JP7096724B2 - Non-aqueous lithium storage element - Google Patents

Description

The present invention relates to a non-aqueous lithium storage element.

In recent years, from the viewpoint of energy conservation and effective use of energy aiming at conservation of global environment, power smoothing system or midnight power storage system for wind power generation, distributed power storage system for home use based on solar power generation technology, power storage for electric vehicles Systems and the like are attracting attention.
The first requirement of the batteries used in these power storage systems is high energy density. Lithium-ion batteries are being energetically developed as promising candidates for high-energy density batteries that can meet such demands.
The second requirement is that the output characteristics are high. For example, in a combination of a high efficiency engine and a power storage system (for example, a hybrid electric vehicle) or a combination of a fuel cell and a power storage system (for example, a fuel cell electric vehicle), high output discharge characteristics in the power storage system are required at the time of acceleration. There is. Currently, electric double layer capacitors, nickel-metal hydride batteries, and the like are being developed as high-output power storage devices.

Among the electric double layer capacitors, those using activated carbon for the electrodes have an output characteristic of about 0.5 to 1 kW / L. This electric double layer capacitor has high durability (cycle characteristics and high temperature storage characteristics), and has been considered to be the most suitable device in the above-mentioned field where high output is required. However, its energy density is only about 1 to 5 Wh / L. Therefore, it is necessary to further improve the energy density.

On the other hand, the nickel-metal hydride battery currently used in a hybrid electric vehicle has a high output equivalent to that of an electric double layer capacitor and an energy density of about 160 Wh / L. However, research is being vigorously pursued to further increase its energy density and output, as well as to improve its durability (particularly, stability at high temperatures).
In addition, research is underway to increase the output of lithium-ion batteries. For example, a lithium ion battery has been developed in which a high output exceeding 3 kW / L can be obtained at a discharge depth (a value indicating what percentage of the discharge capacity of the power storage element is in a discharged state) of 50%. However, the energy density is 100 Wh / L or less, and the design is such that the high energy density, which is the greatest feature of the lithium ion battery, is intentionally suppressed. Moreover, its durability (cycle characteristics and high temperature storage characteristics) is inferior to that of electric double layer capacitors. Therefore, in order to have practical durability, it is used in a range where the discharge depth is narrower than the range of 0 to 100%. Since the capacity that can actually be used becomes smaller, research is being vigorously pursued to further improve the durability of lithium-ion batteries.
As described above, there is a strong demand for practical use of a power storage element having high energy density, high output characteristics, and durability. However, each of the existing power storage elements described above has advantages and disadvantages. Therefore, there is a demand for a new power storage element that satisfies these technical requirements. As a promising candidate, a power storage element called a lithium ion capacitor has attracted attention and is being actively developed.
The energy of the capacitor is represented by 1/2 · C · V ² (where C is the capacitance and V is the voltage).

A lithium-ion capacitor is a type of power storage element (non-aqueous lithium-type power storage element) that uses a non-aqueous electrolyte solution containing a lithium salt. -A power storage element that charges and discharges by a non-Faraday reaction due to desorption, and a Faraday reaction by the storage and release of lithium ions at the negative electrode, similar to a lithium ion battery.
To summarize the above-mentioned electrode materials and their characteristics, high output and high durability are achieved when charging and discharging are performed by adsorption / desorption (non-Faraday reaction) of ions on the surface of activated carbon using a material such as activated carbon for the electrodes. However, the energy density becomes low (for example, it is multiplied by 1). On the other hand, when an oxide or carbon material is used for the electrode and charging / discharging is performed by the Faraday reaction, the energy density becomes high (for example, 10 times that of the non-Faraday reaction using activated carbon), but the durability and output characteristics are increased. There is a problem in.
As a combination of these electrode materials, the electric double-layer capacitor uses activated carbon (energy density 1 times) for the positive electrode and the negative electrode, and both the positive and negative electrodes are charged and discharged by a non-Faraday reaction, and have high output and high durability. However, it is characterized by low energy density (1x positive electrode x 1x negative electrode = 1).

Lithium-ion secondary batteries are characterized by using a lithium transition metal oxide (energy density 10 times) for the positive electrode and a carbon material (energy density 10 times) for the negative electrode, and charging and discharging both the positive and negative electrodes by a Faraday reaction. Although the energy density is 10 times the positive electrode x 10 times the negative electrode = 100, there are problems in output characteristics and durability. Further, in order to satisfy the high durability required for a hybrid electric vehicle or the like, the discharge depth must be limited, and a lithium ion secondary battery can use only 10 to 50% of its energy.
Lithium-ion capacitors use activated carbon (1x energy density) for the positive electrode and carbon material (10x energy density) for the negative electrode, and are characterized by performing charging and discharging by a non-Faraday reaction at the positive electrode and a Faraday reaction at the negative electrode. It is a new asymmetric capacitor that combines the characteristics of a multi-layer capacitor and a lithium-ion secondary battery. Therefore, it is necessary for a lithium ion capacitor to have a high energy density (1x positive electrode x 10x negative electrode = 10) while having high output and high durability, and to limit the discharge depth like a lithium ion secondary battery. The feature is that there is no such thing.

Examples of applications using lithium ion capacitors include electric storage for railways, construction machinery, and automobiles. In these applications, the operating environment is harsh, so the capacitors used must have excellent temperature characteristics. In particular, there is a problem of performance deterioration caused by gas generation due to decomposition of the electrolytic solution at high temperature and deterioration of the negative electrode interface. As a countermeasure against such problems, an additive is added to the non-aqueous electrolyte solution to form a film composed of its decomposition products on the surface of the negative electrode active material, thereby reducing the non-aqueous electrolyte solution with subsequent charge and discharge. There is a technology that suppresses disassembly and improves the durability of the battery.

As a technique related to this, in Patent Document 1, gas generation inside a battery in a high temperature environment is suppressed by adding an additive that decomposes in a specific potential range to form a film on a negative electrode. In Patent Document 3, the cycle durability of the battery is improved by forming a film containing lithium oxide on the surface of the negative electrode. Patent Document 2 proposes a technique for improving low temperature characteristics and high temperature durability by simultaneously containing a cyclic ester and a sulfonic acid ester derivative to optimize the coating state of the negative electrode. In Patent Document 4, it is attempted to suppress the reduction decomposition reaction at the negative electrode interface by containing an unsaturated sultone compound and a phosphazene compound in the electrolytic solution, and to exhibit a high capacity retention rate and a gas suppressing effect. ..

In Patent Document 5, a specific sulfur compound is contained in the negative electrode active material layer, and a cyclic sulfur compound is contained in the non-aqueous electrolyte solution to achieve both low temperature characteristics and high temperature durability. Further, in Patent Document 6, by controlling the ratio of the sulfur compound contained in the negative electrode active material layer and the positive electrode active material layer within a certain range, the low temperature characteristics are improved and the gas generation and the resistance increase at the high temperature are suppressed. Are compatible. In Patent Document 7, by containing a specific lithium salt, a sulfate compound and a vinyl carbonate in the electrolytic solution, not only the high temperature storage characteristic and the high temperature cycle characteristic can be maintained high, but also the battery resistance at a low temperature is lowered and the low temperature output characteristic is achieved. Techniques to improve are also proposed.

In the present specification, the mesopore amount is calculated by the BJH method and the micropore amount is calculated by the MP method. However, the BJH method is proposed in Non-Patent Document 1, and the MP method is "t-. It means a method of obtaining a micropore volume, a micropore area, and a distribution of micropores by using a "plot method" (Non-Patent Document 2), and is shown in Non-Patent Document 3.

Japanese Unexamined Patent Publication No. 2013-152824 Japanese Unexamined Patent Publication No. 2016-86153 Japanese Unexamined Patent Publication No. 2016-85975 Japanese Unexamined Patent Publication No. 2014-27196 Japanese Unexamined Patent Publication No. 2017-21238 Japanese Unexamined Patent Publication No. 2018-5426 Japanese Patent Publication No. 2011-517402

E. P. Barrett, L. G. Joiner and P. Hallenda, J. Mol. Am. Chem. Soc. , 73, 373 (1951) B. C. Lippens, J. Mol. H. de Boer, J.M. Catalysis, 4319 (1965) R. S. Mikhair, S.M. Brunar, E. et al. E. Border, J. et al. Colloid Interface Sci. , 26,45 (1968)

The techniques described in Patent Documents 1, 3 and 4 suppress gas generation and electrode deterioration in a high temperature environment, but do not mention low temperature characteristics. Patent Document 2 proposes a technique for improving both low temperature characteristics and high temperature durability. However, since a power storage element capable of maintaining high output in an extremely low temperature environment below -30 ° C is required for in-vehicle use, the temperature is low. It can be said that the characteristics are insufficient. In addition, all of these techniques suppress the deterioration of gas and electrodes during high-temperature storage by forming a film on the negative electrode interface, and the gas generated by the oxidative decomposition of the electrolytic solution at the positive electrode interface and the deterioration of the positive electrode interface. No mention is made of the performance degradation caused.
The techniques described in Patent Documents 5 or 6 both improve low-temperature characteristics and suppress gas generation and resistance increase at high temperatures, but suppress capacity deterioration when placed in a high-temperature environment. The effect is not specified.
In Patent Document 7, a protective film is formed at the interface of the negative electrode by impregnating two kinds of compounds and a specific lithium salt in the non-aqueous electrolyte solution to achieve both low temperature characteristics and high temperature durability. In order to improve the durability when placed in a high temperature environment in a high voltage region of .0 V or higher, it is necessary to consider deterioration due to oxidative decomposition of the positive electrode interface.

As described above, conventional lithium-ion capacitors focus on either low-temperature characteristics, gas generation in high-temperature environments, or increased resistance, or by suppressing only deterioration of the negative electrode interface, these problems We are trying to solve it.
However, when considering the mounting of capacitors in automobiles or construction machinery, in addition to excellent low-temperature characteristics that do not deteriorate even at -30 ° C and can maintain high output, high output even after long-term exposure to high-temperature environments. Durability that can maintain high capacity is required. In particular, by suppressing capacity deterioration when the power storage device is used in a high voltage and high temperature environment, it is possible to maintain the function of the power storage system for a long period of time.
In order to obtain sufficient high temperature durability while maintaining excellent low temperature characteristics, it is necessary to suppress decomposition of the electrolytic solution at both the negative electrode interface and the positive electrode interface. In view of the above circumstances, the problem to be solved by the present invention is to provide excellent low temperature characteristics while adding sufficient high temperature durability required for automobiles or construction machines even in a high voltage region of 4.0 V or higher. It is to provide the non-aqueous lithium type electricity storage element shown.

｛式中、Ｘ^１は、水素、リチウム、炭素数１～６のアルキル基、炭素数１～６のモノ若しくはポリヒドロキシアルキル基又はそのリチウムアルコキシド、炭素数２～６のアルケニル基、炭素数２～６のモノ若しくはポリヒドロキシアルケニル基又はそのリチウムアルコキシド、炭素数３～６のシクロアルキル基、又はアリール基であり、そしてＸ^２は、水素、リチウム、又は炭素数１～１２のアルキル基である。｝
で表される硫黄化合物を含み、
該正極活物質層に含まれる上記式（１）で表される硫黄化合物の総量が、該正極活物質層の単位質量当たり０．１０×１０^－５ｍｏｌ／ｇ～５０×１０^－５ｍｏｌ／ｇであり、
該負極活物質層に含まれる上記式（１）で表される硫黄化合物の総量が、該負極活物質層の単位質量当たり０．１０×１０^－５ｍｏｌ／ｇ～４０×１０^－５ｍｏｌ／ｇであり、かつ
該正極活物質層の単位質量当たりの含有量をＡ、
該負極活物質層の単位質量当たりの含有量をＢ、
としたとき０．５０≦Ａ／Ｂ≦１２である非水系リチウム型蓄電素子。
［２］
前記非水系電解液が、下記式（１－１）：

｛式中、Ｒ^５～Ｒ^８は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表される環状硫酸化合物を、前記非水系電解液の総量を基準として、０．１質量％～５質量％含有する、項目１に記載の非水系リチウム型蓄電素子。
［３］
前記非水系電解液が、下記式（１－２）：

｛式中、Ｒ^１～Ｒ^４は、それぞれ独立に、水素原子、ハロゲン原子、ホルミル基、アセチル基、ニトリル基、アセチル基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、及び炭素数１～６のアルキルエステルから成る群から選択される少なくとも１つを表す。｝
で表されるチオフェン化合物；
下記式（１－３）：

｛式中、Ｒ^９～Ｒ^１４は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表されるスルトン化合物；
下記式（１－４）：

｛式中、Ｒ^１５～Ｒ^２０は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表されるスルトン化合物；
下記式（１－５）：

｛式中、Ｒ^２１～Ｒ^２６は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよい。｝
で表される化合物；並びに
下記式（１－６）：

｛式中、Ｒ^２７～Ｒ^３０は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表される環状亜硫酸化合物から成る群から選択される少なくとも１つの含硫黄化合物を、前記非水系電解液の総量を基準として、０．１質量％～５質量％含有する、項目１又は２に記載の非水系リチウム型蓄電素子。
［４］
前記式（１－１）で表される環状硫酸化合物が、エチレンスルファート、１，２－プロピレンスルファート、またはトリメチレンスルファートである、項目１～３のいずれか１項に記載の非水系リチウム型蓄電素子。
［５］
前記式（１－２）で表されるチオフェン化合物が、チオフェン、２－メチルチオフェン、３－メチルチオフェン、２－シアノチオフェン、３－シアノチオフェン、２，５－ジメチルチオフェン、２－メトキシチオフェン、３－メトキシチオフェン、２－クロロチオフェン、３－クロロチオフェン、２－アセチルチオフェン又は３－アセチルチオフェンであり、
前記式（１－３）で表されるスルトン化合物が、１，３－プロパンスルトン、２，４－ブタンスルトン、１，４－ブタンスルトン、１，３－ブタンスルトン又は２，４－ペンタンスルトンであり、
前記式（１－４）で表されるスルトン化合物が、１，３－プロペンスルトン又は１，４－ブテンスルトンであり、
前記式（１－５）で表される化合物が、３－スルフォレンであり、かつ
前記式（１－６）で表される環状亜硫酸化合物が、亜硫酸エチレン、１，２－亜硫酸プロピレン又は１，３－亜硫酸プロピレンである、項目３に記載の非水系リチウム型蓄電素子。
［６］
前記非水系電解液が、下記式（２）：

｛式中、Ｘ^１～Ｘ^３は、それぞれ独立に、水素原子、ハロゲン原子、ホルミル基、アセチル基、ニトリル基、アセチル基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数１～６のアルキルエステル、又は－Ｓｉ（Ｒ^１）_３（式中、Ｒ^１は炭素数１～６のアルキル基を表す。）を表し、かつＸ^１～Ｘ^３の少なくとも１つは、水素原子ではない。｝
で表されるリン酸エステル化合物を、非水系電解液の総量を基準として、０．１質量％～３質量％含有する、項目１～５のいずれか１項に記載の非水系リチウム型蓄電素子。
［７］
前記式（２）で表されるリン酸エステル化合物が、トリメチルホスフェート、トリエチルホスフェート、トリブチルホスフェート、リン酸トリス（トリメチルシリル）、トリトリルホスフェート、トリフェニルホスフェート、又はジオクチルホスフェートである、項目６に記載の非水系リチウム型蓄電素子。
［８］
前記非水系電解液に下記式（３）：
Ｒ^３１－Ｏ－Ｒ^３２ （３）
｛式中、Ｒ^３１は、ハロゲン原子又は炭素数１～１２のハロゲン化アルキル基であり、かつＲ^３２は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、又は炭素数１～１２のハロゲン化アルキル基である。｝
で表される非環状含ハロゲンエーテルを、前記非水系電解液の総量を基準として、０．１質量％～３質量％含有する、項目１～７のいずれか１項に記載の非水系リチウム型蓄電素子。
［９］
前記式（３）で表される非環状含ハロゲンエーテルが、Ｃ_２Ｆ_５ＯＣ_２Ｆ_５、Ｃ_３Ｆ_７ＯＣ_３Ｆ_７、Ｃ_４Ｆ_９ＯＣ_４Ｆ_９、Ｃ_６Ｆ_１３ＯＣ_６Ｆ_１３、Ｃ_２Ｆ_５ＯＣＨ_３、Ｃ_３Ｆ_７ＯＣＨ_３、Ｃ_４Ｆ_９ＯＣＨ_３、Ｃ_６Ｆ_１３ＯＣＨ_３、Ｃ_２Ｆ_５ＯＣＨ_５、Ｃ_３Ｆ_７ＯＣＨ_５、Ｃ_４Ｆ_９ＯＣ_２Ｈ_５、Ｃ_２Ｆ_５ＣＦ（ＯＣＨ_３）Ｃ_３Ｆ_７、ＣＦ_３ＣＨ_２ＯＣＦ_２ＣＦ_２Ｈ、ＣＨＦ_２ＣＦ_２ＯＣＨ_２ＣＦ_３、ＣＨＦ_２ＣＦ_２ＣＨ_２ＯＣＦ_２ＣＦ_２Ｈ、ＣＦ_３ＣＦ_２ＣＨ_２ＯＣＦ_２ＣＨＦ_２、ＣＦ_３ＣＨ_２ＯＣＦ_２ＣＨＦＣＦ_３、及びＣ_３ＨＦ_６ＣＨ（ＣＨ_３）ＯＣ_３ＨＦ_６から成る群から選ばれた少なくとも一種の化合物である、項目８に記載の非水系リチウム型蓄電素子。
［１０］
前記非水系電解液が、ＬｉＰＦ_６、ＬｉＣｌＯ_４、及びＬｉＢＦ_４のうち少なくとも１種を含有する、項目１～９のいずれか１項に記載の非水系リチウム型蓄電素子。
［１１］
前記非水系電解液におけるＬｉＮ（ＳＯ_２Ｆ）_２の濃度が、前記非水系電解液の総量を基準として０．１ｍｏｌ／Ｌ以上１．５ｍｏｌ／Ｌ以下である、項目１～１０のいずれか１項に記載の非水系リチウム型蓄電素子。
［１２］
前記非水系電解液が、ジメチルカーボネート（ＤＭＣ）とエチルメチルカーボネート（ＥＭＣ）を含有し、かつ前記エチルメチルカーボネートに対する前記ジメチルカーボネートの体積比率（ＤＭＣ／ＥＭＣ）が、０．５以上８．０以下である、項目１～１１のいずれか１項に記載の非水系リチウム型蓄電素子。
［１３］
前記正極がアルカリ金属炭酸塩を含有し、該アルカリ金属炭酸塩が、炭酸リチウム、炭酸ナトリウム、炭酸カリウム、炭酸ルビジウム、及び炭酸セシウムから成る群から選ばれる１種以上であり、前記正極活物質の総量に対する該アルカリ金属炭酸塩の含有量が、１質量％以上５０質量％以下である、項目１～１２のいずれか１項に記載の非水系リチウム型蓄電素子。
［１４］
前記正極集電体及び前記負極集電体が無孔状の金属箔である、項目１～１３のいずれか１項に記載の非水系リチウム型蓄電素子。
［１５］
前記負極活物質が、少なくとも２種類である、項目１～１４のいずれか１項に記載の非水系リチウム型蓄電素子。
［１６］
前記負極活物質が少なくとも２種類であり、かつ少なくとも１種の負極活物質の平均粒子径が、１μｍ以上１５μｍ以下である、項目１～１５のいずれか１項に記載の非水系リチウム型蓄電素子。
［１７］
前記負極が、天然黒鉛、人造黒鉛、低結晶黒鉛、ソフトカーボン、ハードカーボン、又はそれらのいずれかを基材として含む複合化炭素材料Ａより選ばれる少なくとも１種の負極活物質Ａを含有し、かつ、活性炭、カーボンブラック、鋳型多孔質炭素、高比表面積黒鉛、カーボンナノ粒子、又はそれらのいずれかを基材として含む複合化炭素材料Ｂより選ばれる少なくとも１種の負極活物質Ｂを含有する、項目１～１６のいずれか１項に記載の非水系リチウム型蓄電素子。
［１８］
前記負極活物質Ｂの比率が、前記負極活物質層に含まれる前記負極活物質の総量を基準として、１．０質量％～４５．０質量％である、項目１７に記載の非水系リチウム型蓄電素子。
［１９］
前記負極活物質ＡのＢＥＴ比表面積が０．５ｍ^２／ｇ以上３５ｍ^２／ｇ以下であり、かつ前記負極活物質ＢのＢＥＴ比表面積が５０ｍ^２／ｇ以上１，５００ｍ^２／ｇ以下である、項目１７又は１８に記載の非水系リチウム型蓄電素子。
［２０］
前記負極活物質Ａのリチウムイオンのドープ量が、単位質量当たり５０ｍＡｈ／ｇ以上５２０ｍＡｈ／ｇ以下である、項目１７～１９のいずれか１項に記載の非水系リチウム型蓄電素子。
［２１］
前記負極活物質Ｂのリチウムイオンのドープ量が、単位質量当たり５３０ｍＡｈ／ｇ以上２，５００ｍＡｈ／ｇ以下である、項目１７～２０のいずれか１項に記載の非水系リチウム型蓄電素子。
［２２］
前記正極活物質層に含まれる前記正極活物質が、ＢＪＨ法により算出した直径２０Å以上５００Å以下の細孔に由来するメソ孔量をＶ１（ｃｃ／ｇ）、ＭＰ法により算出した直径２０Å未満の細孔に由来するマイクロ孔量をＶ２（ｃｃ／ｇ）とするとき、０．３＜Ｖ１≦０．８、及び０．５≦Ｖ２≦１．０を満たし、かつ、ＢＥＴ法により測定される比表面積が１，５００ｍ^２／ｇ以上３，０００ｍ^２／ｇ以下を示す活性炭である、項目１～２１のいずれか１項に記載の非水系リチウム型蓄電素子。
［２３］
前記正極活物質層に含まれる前記正極活物質が、ＢＪＨ法により算出した直径２０Å以上５００Å以下の細孔に由来するメソ孔量Ｖ１（ｃｃ／ｇ）が０．８＜Ｖ１≦２．５を満たし、ＭＰ法により算出した直径２０Å未満の細孔に由来するマイクロ孔量Ｖ２（ｃｃ／ｇ）が０．８＜Ｖ２≦３．０を満たし、かつ、ＢＥＴ法により測定される比表面積が２，３００ｍ^２／ｇ以上４，０００ｍ^２／ｇ以下を示す活性炭である、項目１～２１のいずれか１項に記載の非水系リチウム型蓄電素子。
［２４］
前記正極活物質が、リチウムイオンを吸蔵及び放出可能な遷移金属酸化物を含む、項目１～２３のいずれか１項に記載の非水系リチウム型蓄電素子。
［２５］
前記遷移金属酸化物が、層状構造、オリビン構造、又はスピネル構造を有するリチウム金属複合酸化物である、項目２４に記載の非水系リチウム型蓄電素子。
［２６］
前記遷移金属酸化物が、
Ｌｉ_ｘ１ＣｏＯ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１ＮｉＯ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１Ｎｉ_ｙＭ^１ _{（１－ｙ）}Ｏ_２（式中、Ｍ^１はＣｏ、Ｍｎ、Ａｌ、Ｆｅ、Ｍｇ、及びＴｉから成る群より選ばれる少なくとも１種の元素であり、ｘ１は、０≦ｘ１≦２を満たし、かつｙは０．２＜ｙ＜０．９７を満たす。）、
Ｌｉ_ｘ１Ｎｉ_１／３Ｃｏ_１／３Ｍｎ_１／３Ｏ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１ＭｎＯ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
α－Ｌｉ_ｘ１ＦｅＯ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１ＶＯ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１ＣｒＯ_２（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１Ｍｎ_２Ｏ_４（式中、ｘ１は、０≦ｘ１≦２を満たす。）、
Ｌｉ_ｘ１Ｍ^２ _ｙＭｎ_{（２－ｙ）}Ｏ_４（Ｍ^２はＣｏ、Ｎｉ、Ａｌ、Ｆｅ、Ｍｇ、及びＴｉから成る群より選ばれる少なくとも１種の元素であり、ｘ１は、０≦ｘ１≦２を満たし、かつｙは０．２＜ｙ＜０．９７を満たす。）、
Ｌｉ_ｘ１Ｎｉ_ａＣｏ_ｂＡｌ_{（１－ａ－ｂ）}Ｏ_２（式中、ｘ１は、０≦ｘ１≦２を満たし、かつａ及びｂは、それぞれ０．２＜ａ＜０．９７、０．２＜ｂ＜０．９７を満たす。）、
Ｌｉ_ｘ１Ｎｉ_ｃＣｏ_ｄＭｎ_{（１－ｃ－ｄ）}Ｏ_２（式中、ｘ１は、０≦ｘ１≦２を満たし、かつｃ及びｄは、それぞれ０．２＜ｃ＜０．９７、０．２＜ｄ＜０．９７を満たす。）、
Ｌｉ_ｘ１Ｍ^３ＰＯ_４（式中、Ｍ^３はＣｏ、Ｎｉ、Ｆｅ、Ｍｎ、及びＣｕから成る群より選ばれる少なくとも１種の元素であり、かつｘ１は、０≦ｘ１≦２を満たす。）、及び
Ｌｉ_ｚＶ_２（ＰＯ_４）_３（式中、ｚは０≦ｚ≦３を満たす）から成る群より選ばれる少なくとも１種のリチウム金属複合酸化物を含む、項目２４又は２５に記載の非水系リチウム型蓄電素子。
［２７］
前記遷移金属酸化物が、Ｌｉ_ｘ２ＦｅＰＯ_４（式中、ｘ２は、０≦ｘ１≦２を満たす。）、Ｌｉ_ｘ２ＣｏＰＯ_４（式中、ｘ２は、０≦ｘ１≦２を満たす。）、及びＬｉ_ｘ２ＭｎＰＯ_４（式中、ｘ２は、０≦ｘ１≦２を満たす。）から成る群より選ばれる少なくとも１種のリチウム金属複合酸化物を含む、項目２４～２６のいずれか１項に記載の非水系リチウム型蓄電素子。
［２８］
前記活性炭の平均粒子径が、２μｍ以上２０μｍ以下であり、前記遷移金属酸化物の平均粒子径が、０．１μｍ以上２０μｍ以下である、項目２４～２７のいずれか１項に記載の非水系リチウム型蓄電素子。
［２９］
前記遷移金属酸化物の含有率が、前記正極活物質層の総重量を基準として、１．０質量％～５０．０質量％である、項目２４～２８のいずれか１項に記載の非水系リチウム型蓄電素子。
［３０］
セル電圧４．２Ｖでの初期の内部抵抗をＲａ（Ω）、静電容量をＦ（Ｆ）、電力量をＥ（Ｗｈ）、前記電極積層体を収納している前記外装体の体積をＶ（Ｌ）、環境温度－３０℃における内部抵抗をＲｃとした時、以下の（ａ）、（ｂ）及び（ｃ）の要件：
（ａ）ＲａとＦの積Ｒａ・Ｆが０．５以上３．５以下である；
（ｂ）Ｅ／Ｖが２０以上８０以下である；及び
（ｃ）Ｒｃ／Ｒａが３０以下である；
を同時に満たす、項目１～２９のいずれか１項に記載の非水系リチウム型蓄電素子。
［３１］
セル電圧４．２Ｖでの初期の内部抵抗をＲａ（Ω）、静電容量をＦａ（Ｆ）、セル電圧４．２Ｖ及び環境温度６０℃において２か月間保存した後の２５℃における内部抵抗をＲｂ（Ω）及び静電容量をＦｂ（Ｆ）としたとき、以下の（ｄ）、（ｅ）及び（ｆ）の要件：
（ｄ）Ｒｂ／Ｒａが０．８以上３．０以下である；
（ｅ）Ｆｂ／Ｆａが０．５以上１．２以下である；並びに
（ｆ）セル電圧４．２Ｖ及び環境温度６０℃において２か月間保存した時に発生するガス量が、２５℃において３０×１０^－３ｃｃ／Ｆ以下である；
を同時に満たす、項目１～３０のいずれか１項に記載の非水系リチウム型蓄電素子。
［３２］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を構成する前記正極の前駆体である正極前駆体の製造方法であって、
前記正極前駆体は、集電体と前記集電体上に配置された正極活物質層とを有し、
前記正極活物質層は、正極活物質、及びアルカリ金属化合物を含み、
前記正極活物質は、炭素材料を含み、かつ
下記の工程１）、２）、３）、４）及び５）：
１）前記炭素材料を含む前記正極活物質と、前記アルカリ金属化合物とを混錬して、塗工液を作製する塗工液作製工程；
２）前記塗工液を前記集電体に塗布して正極前駆体を作製する塗布工程；
３）前記正極前駆体を４５℃以上２００℃以下の温度で乾燥する一次乾燥工程；
４）前記正極前駆体を０．５ｋＮ／ｃｍ^２以上２０ｋＮ／ｃｍ^２以下の線圧でプレスするプレス工程；及び
５）前記正極前駆体を１６０℃以上２５０℃以下の温度で乾燥する二次乾燥工程；
を含む正極前駆体の製造方法。
［３３］
前記４）プレス工程の前に前記５）二次乾燥工程を行う、項目３２に記載の正極前駆体の製造方法。
［３４］
前記４）プレス工程の前に、前記３）一次乾燥工程と前記５）二次乾燥工程を一体化させた一体化乾燥工程を行う、項目３２に記載の正極前駆体の製造方法。
［３５］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を構成する前記負極の製造方法であって、
前記負極は、集電体と前記集電体上に配置された負極活物質層とを有し、
下記の工程１）、２）、３）、４）及び５）：
１）炭素材料を含む負極活物質と、アルカリ金属化合物とを混錬して、塗工液を作製する塗工液作製工程；
２）前記塗工液を前記集電体に塗布して、負極を作製する塗布工程；
３）前記負極を４５℃以上２００℃以下の温度で乾燥する一次乾燥工程；
４）前記負極を０．５ｋＮ／ｃｍ^２以上２０ｋＮ／ｃｍ^２以下の線圧でプレスするプレス工程；及び
５）前記負極を１６０℃以上２５０℃以下の温度で乾燥する二次乾燥工程；
を含む負極の製造方法。
［３６］
前記４）プレス工程の前に前記５）二次乾燥工程を行う、項目３５に記載の負極の製造方法。
［３７］
前記４）プレス工程の前に、前記３）一次乾燥工程と前記５）二次乾燥工程を一体化させた一体化乾燥工程を行う、項目３５に記載の負極の製造方法。
［３８］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む蓄電モジュール。
［３９］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む電力回生アシストシステム。
［４０］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む電力負荷平準化システム。
［４１］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む無停電電源システム。
［４２］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む非接触給電システム。
［４３］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含むエナジーハーベストシステム。
［４４］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む蓄電システム。
［４５］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子と、鉛電池、ニッケル水素電池、リチウムイオン二次電池又は燃料電池とを直列又は並列に接続した蓄電システム。
［４６］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む太陽光発電蓄電システム。
［４７］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む電動パワーステアリングシステム。
［４８］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む非常用電源システム。
［４９］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含むインホイールモーターシステム。
［５０］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含むアイドリングストップシステム。
［５１］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む乗り物。
［５２］
電気自動車、プラグインハイブリッド自動車、ハイブリッド自動車、又は電動バイクである、項目５１に記載の乗り物。
［５３］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含む急速充電システム。
［５４］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含むスマートグリッドシステム。
［５５］
項目１～３１のいずれか１項に記載の非水系リチウム型蓄電素子を含むハイブリッドショベル。 The above problems are solved by the following technical means.
[1]
A non-aqueous lithium storage element including an electrode laminate having a negative electrode, a positive electrode and a separator, a non-aqueous electrolyte solution, and an exterior body accommodating the electrode laminate and the non-aqueous electrolyte solution.
The negative electrode has a negative electrode current collector and a negative electrode active material layer containing a negative electrode active material provided on one side or both sides of the negative electrode current collector, and the negative electrode active material stores lithium ions. Contains carbon material that can be released
The positive electrode has a positive electrode current collector and a positive electrode active material layer containing a positive electrode active material provided on one side or both sides of the positive electrode current collector, and the positive electrode active material contains activated carbon.
The negative electrode active material layer and the positive electrode active material layer have the following formula (1):

{In the formula, X ¹ is hydrogen, lithium, an alkyl group having 1 to 6 carbon atoms, a mono or polyhydroxyalkyl group having 1 to 6 carbon atoms or a lithium alkoxide thereof, an alkenyl group having 2 to 6 carbon atoms, and 2 carbon atoms. A mono or polyhydroxyalkenyl group of ~ 6 or a lithium alkoxide thereof, a cycloalkyl group or an aryl group having 3 to 6 carbon atoms, and X ² is a hydrogen, lithium, or an alkyl group having 1 to 12 carbon atoms. .. }
Contains sulfur compounds represented by
The total amount of the sulfur compound represented by the above formula (1) contained in the positive electrode active material layer is 0.10 × 10 ^-5 mol / g to 50 × 10 ^-5 mol / g per unit mass of the positive electrode active material layer. g,
The total amount of the sulfur compound represented by the above formula (1) contained in the negative electrode active material layer is 0.10 × 10 ^-5 mol / g to 40 × 10 ^-5 mol / g per unit mass of the negative electrode active material layer. g, and the content per unit mass of the positive electrode active material layer is A,
The content of the negative electrode active material layer per unit mass is B,
A non-aqueous lithium-type power storage element having 0.50 ≦ A / B ≦ 12.
[2]
The non-aqueous electrolyte solution has the following formula (1-1):

{In the formula, R ⁵ to R ⁸ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Item 2. The non-aqueous lithium power storage element according to Item 1, which contains the cyclic sulfuric acid compound represented by 1 in 0.1% by mass to 5% by mass based on the total amount of the non-aqueous electrolyte solution.
[3]
The non-aqueous electrolyte solution has the following formula (1-2):

{In the formula, R ¹ to R ⁴ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , And at least one selected from the group consisting of alkyl esters having 1 to 6 carbon atoms. }
Thiophene compound represented by;
The following formula (1-3):

{In the formula, R ⁹ to R ¹⁴ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Sultone compound represented by;
The following formula (1-4):

{In the formula, R ¹⁵ to R ²⁰ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Sultone compound represented by;
The following formula (1-5):

{In the formula, R ²¹ to R ²⁶ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different. }
The compound represented by; and the following formula (1-6):

{In the formula, R ²⁷ to R ³⁰ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Item 1 or 2 containing at least one sulfur-containing compound selected from the group consisting of the cyclic sulfite compound represented by the above in an amount of 0.1% by mass to 5% by mass based on the total amount of the non-aqueous electrolyte solution. The non-aqueous lithium-type power storage element described.
[4]
Item 3. The non-aqueous system according to any one of Items 1 to 3, wherein the cyclic sulfuric acid compound represented by the formula (1-1) is ethylene sulfate, 1,2-propylene sulfate, or trimethylene sulfate. Lithium-type power storage element.
[5]
The thiophene compound represented by the above formula (1-2) is thiophene, 2-methylthiophene, 3-methylthiophene, 2-cyanothiophene, 3-cyanothiophene, 2,5-dimethylthiophene, 2-methoxythiophene, 3 -Methoxythiophene, 2-chlorothiophene, 3-chlorothiophene, 2-acetylthiophene or 3-acetylthiophene,
The sultone compound represented by the above formula (1-3) is 1,3-propane sultone, 2,4-butane sultone, 1,4-butane sultone, 1,3-butane sultone or 2,4-pentane sultone.
The sultone compound represented by the above formula (1-4) is 1,3-propene sultone or 1,4-butene sultone.
The compound represented by the formula (1-5) is 3-sulfolene, and the cyclic sulfite compound represented by the formula (1-6) is ethylene sulfite, 1,2-propylene sulfite or 1,3. -The non-aqueous lithium-type power storage element according to item 3, which is propylene sulfite.
[6]
The non-aqueous electrolyte solution has the following formula (2):

{In the formula, X ¹ to X ³ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , An alkyl ester having 1 to 6 carbon atoms, or -Si (R ¹ ) ₃ (in the formula, R ¹ represents an alkyl group having 1 to 6 carbon atoms), and at least one of X ¹ to X ³ . Is not a hydrogen atom. }
Item 2. The non-aqueous lithium-type power storage element according to any one of Items 1 to 5, which contains 0.1% by mass to 3% by mass of the phosphoric acid ester compound represented by ..
[7]
Item 6. The item 6 wherein the phosphoric acid ester compound represented by the formula (2) is trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris phosphate (trimethylsilyl), tritryl phosphate, triphenyl phosphate, or dioctyl phosphate. Non-aqueous lithium-type power storage element.
[8]
The following formula (3):
R ³¹ -OR ³² (3)
{In the formula, R ³¹ is a halogen atom or a halogenated alkyl group having 1 to 12 carbon atoms, and R ³² is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, or 1 to 12 carbon atoms. Halogen alkyl group. }
Item 2. The non-aqueous lithium type according to any one of Items 1 to 7, which contains the acyclic halogen-containing ether represented by 1 in 0.1% by mass to 3% by mass based on the total amount of the non-aqueous electrolytic solution. Storage element.
[9]
The acyclic halogen-containing ether represented by the above formula (3) is C ₂ F ₅ OC ₂ F ₅ , C ₃ F ₇ OC ₃ F ₇ , C ₄ F ₉ OC ₄ F ₉ , C ₆ F ₁₃ OC ₆ F. ₁₃ , C ₂ F ₅ OCH ₃ , C ₃ F ₇ OCH ₃ , C ₄ F ₉ OCH ₃ , C ₆ F ₁₃ OCH ₃ , C ₂ F ₅ OCH ₅ , C ₃ F ₇ OCH ₅ , C ₄ F ₉ OC ₂ H ₅ , C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ , CF ₃ CH ₂ OCF ₂ CF ₂ H, CHF ₂ CF ₂ OCH ₂ CF ₃ , CHF ₂ CF ₂ CH ₂ OCF ₂ CF ₂ H, CF ₃ 28, which is at least one compound selected from the group consisting of CF ₂ CH ₂ OCF ₂ CHF ₂ , CF ₃ CH ₂ OCF ₂ CHFCF ₃ , and C ₃ HF ₆ CH (CH ₃ ) OC ₃ HF ₆ . Non-aqueous lithium-type power storage element.
[10]
Item 2. The non-aqueous lithium storage element according to any one of Items 1 to 9, wherein the non-aqueous electrolyte solution contains at least one of LiPF ₆ , LiClO ₄ , and LiBF ₄ .
[11]
Any one of items 1 to 10, wherein the concentration of LiN (SO ₂ F) ₂ in the non-aqueous electrolyte solution is 0.1 mol / L or more and 1.5 mol / L or less based on the total amount of the non-aqueous electrolyte solution. The non-aqueous lithium-type power storage element according to the section.
[12]
The non-aqueous electrolyte solution contains dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC), and the volume ratio (DMC / EMC) of the dimethyl carbonate to the ethyl methyl carbonate is 0.5 or more and 8.0 or less. The non-aqueous lithium-type power storage element according to any one of items 1 to 11.
[13]
The positive electrode contains an alkali metal carbonate, and the alkali metal carbonate is at least one selected from the group consisting of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate, and the positive electrode active material. Item 2. The non-aqueous lithium power storage element according to any one of Items 1 to 12, wherein the content of the alkali metal carbonate with respect to the total amount is 1% by mass or more and 50% by mass or less.
[14]
Item 2. The non-aqueous lithium power storage element according to any one of Items 1 to 13, wherein the positive electrode current collector and the negative electrode current collector are non-porous metal foils.
[15]
Item 2. The non-aqueous lithium-type power storage element according to any one of Items 1 to 14, wherein the negative electrode active material is at least two types.
[16]
Item 2. The non-aqueous lithium power storage element according to any one of Items 1 to 15, wherein the negative electrode active material has at least two types, and the average particle size of at least one type of negative electrode active material is 1 μm or more and 15 μm or less. ..
[17]
The negative electrode contains at least one negative electrode active material A selected from the composite carbon material A containing natural graphite, artificial graphite, low crystalline graphite, soft carbon, hard carbon, or any of them as a base material. It also contains at least one negative electrode active material B selected from the composite carbon material B containing activated carbon, carbon black, template porous carbon, high specific surface graphite, carbon nanoparticles, or any of them as a base material. , The non-aqueous lithium type power storage element according to any one of items 1 to 16.
[18]
Item 17. The non-aqueous lithium type according to Item 17, wherein the ratio of the negative electrode active material B is 1.0% by mass to 45.0% by mass based on the total amount of the negative electrode active material contained in the negative electrode active material layer. Power storage element.
[19]
The BET specific surface area of the negative electrode active material A is 0.5 m ² / g or more and 35 m ² / g or less, and the BET specific surface area of the negative electrode active material B is 50 m ² / g or more and 1,500 m ² / g or less. , Item 17 or 18, a non-aqueous lithium-type power storage element.
[20]
Item 2. The non-aqueous lithium storage element according to any one of Items 17 to 19, wherein the amount of lithium ion doped in the negative electrode active material A is 50 mAh / g or more and 520 mAh / g or less per unit mass.
[21]
Item 2. The non-aqueous lithium-type power storage element according to any one of Items 17 to 20, wherein the amount of lithium ions doped in the negative electrode active material B is 530 mAh / g or more and 2,500 mAh / g or less per unit mass.
[22]
The amount of mesopores derived from pores having a diameter of 20 Å or more and 500 Å or less calculated by the BJH method for the positive electrode active material contained in the positive electrode active material layer is V1 (cc / g), and the diameter is less than 20 Å calculated by the MP method. When the amount of micropores derived from the pores is V2 (cc / g), 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0 are satisfied, and the measurement is performed by the BET method. The non-aqueous lithium-type power storage element according to any one of Items 1 to 21, which is an activated carbon having a specific surface area of 1,500 m ² / g or more and 3,000 m ² / g or less.
[23]
The positive electrode active material contained in the positive electrode active material layer has a mesopore amount V1 (cc / g) of 0.8 <V1 ≦ 2.5 derived from pores having a diameter of 20 Å or more and 500 Å or less calculated by the BJH method. The micropore amount V2 (cc / g) derived from the pores having a diameter of less than 20 Å calculated by the MP method satisfies 0.8 <V2 ≦ 3.0, and the specific surface area measured by the BET method is 2. The non-aqueous lithium power storage element according to any one of Items 1 to 21, which is an activated carbon exhibiting 300 m ² / g or more and 4,000 m ² / g or less.
[24]
Item 2. The non-aqueous lithium storage element according to any one of Items 1 to 23, wherein the positive electrode active material contains a transition metal oxide capable of storing and releasing lithium ions.
[25]
The non-aqueous lithium power storage element according to item 24, wherein the transition metal oxide is a lithium metal composite oxide having a layered structure, an olivine structure, or a spinel structure.
[26]
The transition metal oxide
Li _x1 CoO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 NiO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 Ny M ¹ (1- _{y )} O ₂ (In the formula, M ¹ is at least one element selected from the group consisting of Co, Mn, Al, Fe, Mg, and Ti, and x1 is 0. ≦ x1 ≦ 2 and y satisfies 0.2 <y <0.97),.
Li _x1 Ni _1/3 Co _1/3 Mn _1/3 O ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 MnO ₂ (in the formula, x1 satisfies 0≤x1≤2),
α-Li _x1 FeO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 VO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 CrO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 Mn ₂ O ₄ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 M ² _y Mn _(2-y) O ₄ (M ² is at least one element selected from the group consisting of Co, Ni, Al, Fe, Mg, and Ti, and x1 is 0 ≦ x 1 ≦. 2 and y satisfies 0.2 <y <0.97),
Li _x1 Ni _a Co _b Al _(1-ab) O ₂ (In the formula, x1 satisfies 0≤x1≤2, and a and b are 0.2 <a <0.97, 0., respectively. 2 <b <0.97),
Li _x1 Ni _c Cod Mn _{(1-c-d) O 2} (In the formula, x1 satisfies 0≤x1≤2, and c and d are 0.2 <c <0.97, 0., respectively. 2 <d <0.97),
Li _x1 M ³ PO ₄ (In the formula, M ³ is at least one element selected from the group consisting of Co, Ni, Fe, Mn, and Cu, and x1 satisfies 0≤x1≤2.) 24 or 25, comprising at least one lithium metal composite oxide selected from the group consisting of Li _z V ₂ (PO ₄ ) ₃ (where z satisfies 0 ≦ z ≦ 3). Non-aqueous lithium-type power storage element.
[27]
The transition metal oxide is Li _x2 FePO ₄ (where x2 satisfies 0≤x1≤2), Li _x2 CoPO ₄ (in the equation, x2 satisfies 0≤x1≤2), and. The item 1 of item 24 to 26, which comprises at least one lithium metal composite oxide selected from the group consisting of Li _x2 MnPO ₄ (where x2 satisfies 0≤x1≤2). Non-aqueous lithium type power storage element.
[28]
Item 2. Non-aqueous lithium according to any one of Items 24 to 27, wherein the activated carbon has an average particle size of 2 μm or more and 20 μm or less, and the transition metal oxide has an average particle size of 0.1 μm or more and 20 μm or less. Type storage element.
[29]
Item 2. The non-aqueous system according to any one of Items 24 to 28, wherein the content of the transition metal oxide is 1.0% by mass to 50.0% by mass based on the total weight of the positive electrode active material layer. Lithium-type power storage element.
[30]
The initial internal resistance at a cell voltage of 4.2 V is Ra (Ω), the capacitance is F (F), the amount of power is E (Wh), and the volume of the exterior body containing the electrode laminate is V. (L), where the internal resistance at an ambient temperature of −30 ° C. is Rc, the following requirements (a), (b) and (c):
(A) The product Ra / F of Ra and F is 0.5 or more and 3.5 or less;
(B) E / V is 20 or more and 80 or less; and (c) Rc / Ra is 30 or less;
Item 4. The non-aqueous lithium-type power storage element according to any one of Items 1 to 29, which simultaneously satisfies the above conditions.
[31]
The initial internal resistance at a cell voltage of 4.2 V is Ra (Ω), the capacitance is Fa (F), the cell voltage is 4.2 V, and the internal resistance at 25 ° C after storage at an ambient temperature of 60 ° C for 2 months. When Rb (Ω) and capacitance are Fb (F), the following requirements (d), (e) and (f) are:
(D) Rb / Ra is 0.8 or more and 3.0 or less;
(E) Fb / Fa is 0.5 or more and 1.2 or less; and (f) The amount of gas generated when stored for 2 months at a cell voltage of 4.2 V and an environmental temperature of 60 ° C. is 30 × at 25 ° C. 10 ^-3 cc / F or less;
Item 4. The non-aqueous lithium-type power storage element according to any one of Items 1 to 30, which simultaneously satisfies the above conditions.
[32]
A method for producing a positive electrode precursor, which is a precursor of the positive electrode constituting the non-aqueous lithium-type power storage element according to any one of items 1 to 31.
The positive electrode precursor has a current collector and a positive electrode active material layer arranged on the current collector.
The positive electrode active material layer contains a positive electrode active material and an alkali metal compound, and contains.
The positive electrode active material contains a carbon material and has the following steps 1), 2), 3), 4) and 5) :.
1) A coating liquid preparation step of kneading the positive electrode active material containing the carbon material with the alkali metal compound to prepare a coating liquid;
2) A coating step of applying the coating liquid to the current collector to prepare a positive electrode precursor;
3) Primary drying step of drying the positive electrode precursor at a temperature of 45 ° C. or higher and 200 ° C. or lower;
4) Pressing step of pressing the positive electrode precursor at a linear pressure of 0.5 kN / cm ² or more and 20 kN / cm ² or less; and 5) Secondary drying of drying the positive electrode precursor at a temperature of 160 ° C. or higher and 250 ° C. or lower. Process;
A method for producing a positive electrode precursor including.
[33]
The method for producing a positive electrode precursor according to item 32, wherein the 5) secondary drying step is performed before the 4) pressing step.
[34]
The method for producing a positive electrode precursor according to item 32, wherein an integrated drying step in which the 3) primary drying step and the 5) secondary drying step are integrated before the 4) pressing step is performed.
[35]
The method for manufacturing the negative electrode constituting the non-aqueous lithium-type power storage element according to any one of items 1 to 31.
The negative electrode has a current collector and a negative electrode active material layer arranged on the current collector.
The following steps 1), 2), 3), 4) and 5):
1) A coating liquid preparation step of kneading a negative electrode active material containing a carbon material and an alkali metal compound to prepare a coating liquid;
2) A coating step of applying the coating liquid to the current collector to prepare a negative electrode;
3) Primary drying step of drying the negative electrode at a temperature of 45 ° C. or higher and 200 ° C. or lower;
4) Pressing step of pressing the negative electrode with a linear pressure of 0.5 kN / cm ² or more and 20 kN / cm ² or less; and 5) Secondary drying step of drying the negative electrode at a temperature of 160 ° C. or more and 250 ° C. or less;
A method for manufacturing a negative electrode including.
[36]
The method for manufacturing a negative electrode according to item 35, wherein the 5) secondary drying step is performed before the 4) pressing step.
[37]
Item 35. The method for manufacturing a negative electrode according to item 35, wherein an integrated drying step in which the 3) primary drying step and the 5) secondary drying step are integrated before the 4) pressing step is performed.
[38]
A power storage module including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[39]
A power regeneration assist system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[40]
A power load leveling system including the non-aqueous lithium storage element according to any one of items 1 to 31.
[41]
An uninterruptible power supply system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[42]
A non-contact power feeding system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[43]
An energy harvesting system including the non-aqueous lithium-type power storage element according to any one of items 1 to 31.
[44]
A power storage system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[45]
A power storage system in which a non-aqueous lithium power storage element according to any one of items 1 to 31 and a lead battery, a nickel hydrogen battery, a lithium ion secondary battery, or a fuel cell are connected in series or in parallel.
[46]
A photovoltaic power storage system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[47]
An electric power steering system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[48]
An emergency power supply system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[49]
An in-wheel motor system including the non-aqueous lithium-type power storage element according to any one of items 1 to 31.
[50]
An idling stop system including the non-aqueous lithium power storage element according to any one of items 1 to 31.
[51]
A vehicle including the non-aqueous lithium-type power storage element according to any one of items 1 to 31.
[52]
51. The vehicle according to item 51, which is an electric vehicle, a plug-in hybrid vehicle, a hybrid vehicle, or an electric motor vehicle.
[53]
A quick charging system including the non-aqueous lithium storage element according to any one of items 1 to 31.
[54]
A smart grid system including the non-aqueous lithium-type power storage element according to any one of items 1 to 31.
[55]
A hybrid excavator including the non-aqueous lithium-type power storage element according to any one of items 1 to 31.

According to the present invention, in a lithium ion capacitor, a negative electrode active material contains a carbon material capable of storing and releasing lithium ions, active carbon is used as the positive electrode active material, and the above formula (1) is used in the negative electrode active material layer. High input / output characteristics over a wide temperature range by controlling the ratio of the content of the compound to be obtained and the content of the compound represented by the above formula (1) in the positive electrode active material layer within a certain range. It is possible to achieve both the generation of gas due to the decomposition of the electrolytic solution at a high temperature and the suppression of performance deterioration due to this.

Hereinafter, embodiments of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited to the present embodiment. The upper limit value and the lower limit value in each numerical range of the present embodiment can be arbitrarily combined to form an arbitrary numerical range.
Non-aqueous lithium-type power storage elements generally include a positive electrode, a negative electrode, a separator, an electrolytic solution, and an exterior body as main components. As the electrolytic solution, an organic solvent in which a lithium salt is dissolved (hereinafter referred to as a non-aqueous electrolytic solution) is used.

[Positive electrode]
The positive electrode has a positive electrode current collector and a positive electrode active material layer existing on one side or both sides thereof.
Further, the positive electrode preferably contains a lithium compound as a positive electrode precursor before assembling the power storage element. As will be described later, in the present embodiment, it is preferable to pre-dope the negative electrode with lithium ions in the energy storage element assembling process, but the pre-doping method includes a positive electrode precursor containing the lithium compound, a negative electrode, a separator, and an exterior body. It is preferable to apply a voltage between the positive electrode precursor and the negative electrode after assembling the power storage element using the non-aqueous electrolytic solution. The lithium compound is preferably contained in the positive electrode active material layer formed on the positive electrode current collector of the positive electrode precursor. The lithium compound may be contained in the positive electrode precursor in any embodiment. For example, the lithium compound may be present between the positive electrode current collector and the positive electrode active material layer, or may be present on the surface of the positive electrode active material layer. The lithium compound is preferably contained in the positive electrode active material layer formed on the positive electrode current collector of the positive electrode precursor.
In the present specification, the positive electrode state before the lithium doping process is defined as a positive electrode precursor, and the positive electrode state after the lithium doping process is defined as a positive electrode.

[Positive electrode active material layer]
The positive electrode active material layer contained in the positive electrode contains a positive electrode active material containing activated carbon. In addition to this, the positive electrode active material layer preferably contains an optional component such as a conductive filler, a binder, and a dispersion stabilizer, and more preferably contains a transition metal oxide.
Further, it is preferable that the positive electrode active material layer of the positive electrode precursor contains a lithium compound other than the positive electrode active material.

[Positive electrode active material]
The positive electrode active material contains activated carbon. As the positive electrode active material, only activated carbon may be used, or a transition metal oxide may be mixed in addition to the activated carbon.
Further, other carbon materials as described later may be used in combination. As the carbon material, it is preferable to use a carbon nanotube, a conductive polymer, or a porous carbon material.

There are no particular restrictions on the type of activated carbon used as the positive electrode active material and its raw materials. However, it is preferable to optimally control the pores of the activated carbon in order to achieve both high input / output characteristics and high energy density. Specifically, the amount of mesopores derived from pores having a diameter of 20 Å or more and 500 Å or less calculated by the BJH method is V1 (cc / g), and the amount of micropores derived from pores having a diameter of less than 20 Å calculated by the MP method is used. When V2 (cc / g) is set, in the present embodiment, (1) for high input / output characteristics, 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0 are satisfied. Moreover, activated carbon having a specific surface area measured by the BET method of 1,500 m ² / g or more and 3,000 m ² / g or less (hereinafter, also referred to as activated carbon 1) is preferable, and (2) high energy density is obtained. For this purpose, 0.8 <V1 ≤ 2.5 and 0.8 <V2 ≤ 3.0 are satisfied, and the specific surface area measured by the BET method is 2,300 m ² / g or more and 4,000 m ² /. Activated carbon having a g or less (hereinafter, also referred to as activated carbon 2) is preferable.

Hereinafter, the (1) activated carbon 1 and the (2) activated carbon 2 will be described individually in sequence.
[Activated carbon 1]
The mesopore amount V1 of the activated carbon 1 is preferably a value larger than 0.3 cc / g in terms of increasing the input / output characteristics when incorporated into the power storage element. On the other hand, it is preferably 0.8 cc / g or less from the viewpoint of suppressing a decrease in the bulk density of the positive electrode. The above V1 is more preferably 0.35 cc / g or more and 0.7 cc / g or less, and further preferably 0.4 cc / g or more and 0.6 cc / g or less.
The micropore amount V2 of the activated carbon 1 is preferably 0.5 cc / g or more in order to increase the specific surface area and the capacity of the activated carbon. On the other hand, it is preferably 1.0 cc / g or less from the viewpoint of suppressing the bulk of the activated carbon, increasing the density as an electrode, and increasing the capacity per unit volume. The above V2 is more preferably 0.6 cc / g or more and 1.0 cc / g or less, and further preferably 0.8 cc / g or more and 1.0 cc / g or less. The combination of the lower limit and the upper limit can be arbitrary.

The ratio (V1 / V2) of the mesopore amount V1 to the micropore amount V2 is preferably in the range of 0.3 ≦ V1 / V2 ≦ 0.9. That is, V1 / V2 is preferably 0.3 or more from the viewpoint of increasing the ratio of the mesopore amount to the micropore amount to the extent that deterioration of the output characteristics can be suppressed while maintaining a high capacity. On the other hand, V1 / V2 is preferably 0.9 or less from the viewpoint of increasing the ratio of the micropore amount to the mesopore amount to the extent that the decrease in capacitance can be suppressed while maintaining the high output characteristics. .. The more preferable range of V1 / V2 is 0.4 ≦ V1 / V2 ≦ 0.7, and the more preferable range of V1 / V2 is 0.55 ≦ V1 / V2 ≦ 0.7. The combination of the lower limit and the upper limit can be arbitrary.

The average pore diameter of the activated carbon 1 is preferably 17 Å or more, more preferably 18 Å or more, and most preferably 20 Å or more from the viewpoint of maximizing the output of the obtained power storage element. Further, from the viewpoint of maximizing the capacity, the average pore diameter of the activated carbon 1 is preferably 25 Å or less.

The BET specific surface area of the activated carbon 1 is preferably 1,500 m ² / g or more and 3,000 m ² / g or less, and more preferably 1,500 m ² / g or more and 2,500 m ² / g or less. When the BET specific surface area is 1,500 m2 / g or more, a good energy density is likely to be obtained, while when the BET specific surface area is 3,000 m ² / g or less, a binder is used to maintain the strength of the electrode. Since it is not necessary to add a large amount of energy, the performance per electrode volume is improved. The combination of the lower limit and the upper limit can be arbitrary.

Activated carbon 1 having the above-mentioned characteristics can be obtained, for example, by using the raw materials and the treatment method described below.
In the present embodiment, the carbon source used as the raw material of the activated carbon 1 is not particularly limited. For example, plant-based raw materials such as wood, wood flour, coconut shells, by-products during pulp production, bagasse, waste sugar honey; peat, sub-charcoal, brown charcoal, bituminous charcoal, smokeless charcoal, petroleum distillation residue component, petroleum pitch, coke, coal tar, etc. Fossil raw materials; various synthetic resins such as phenol resin, vinyl chloride resin, vinyl acetate resin, melamine resin, urea resin, resorcinol resin, celluloid, epoxy resin, polyurethane resin, polyester resin, polyamide resin; polybutylene, polybutadiene, polychloroprene, etc. Synthetic rubber; other synthetic wood, synthetic pulp, etc., and carbonized products thereof. Among these raw materials, plant-based raw materials such as coconut shells and wood flour and their carbides are preferable, and coconut shell carbides are particularly preferable, from the viewpoint of mass production and cost.

As the carbonization and activation methods for using these raw materials as the activated carbon 1, for example, known methods such as a fixed bed method, a moving bed method, a fluidized bed method, a slurry method, and a rotary kiln method can be adopted.
As a carbonization method for these raw materials, an inert gas such as nitrogen, carbon dioxide, helium, argon, xenone, neon, carbon monoxide, or combustion exhaust gas, or another gas containing these inert gases as a main component is used. Examples thereof include a method of firing at about 400 to 700 ° C. (preferably 450 to 600 ° C.) for about 30 minutes to 10 hours using a mixed gas.

As a method for activating the carbonized product obtained by the above carbonization method, a gas activation method in which calcination is performed using an activation gas such as steam, carbon dioxide, or oxygen is preferably used. Of these, a method using steam or carbon dioxide as the activating gas is preferable.
In this activation method, the above-mentioned carbide is supplied for 3 to 12 hours (preferably 5 to 11) while supplying the activation gas at a ratio of 0.5 to 3.0 kg / h (preferably 0.7 to 2.0 kg / h). It is preferable to raise the temperature to 800 to 1,000 ° C. over time, more preferably 6 to 10 hours) for activation.
Further, the carbide may be first activated in advance prior to the activation treatment of the carbide. In this primary activation, a method in which a carbon material is usually calcined at a temperature of less than 900 ° C. using an activation gas such as steam, carbon dioxide, or oxygen to activate the gas can be preferably adopted.
By appropriately combining the firing temperature and firing time in the carbonization method with the activation gas supply amount, temperature rise rate, and maximum activation temperature in the activation method, activated carbon 1 having the above characteristics that can be used in the present embodiment is produced. can do.

The average particle size of the activated carbon 1 is preferably 2 to 20 μm.
When the average particle size is 2 μm or more, the capacity per electrode volume tends to be high because the density of the active material layer is high. Here, if the average particle size is small, the durability may be low, but if the average particle size is 2 μm or more, such a defect is unlikely to occur. On the other hand, when the average particle size is 20 μm or less, it tends to be easy to adapt to high-speed charging / discharging. The average particle size is more preferably 2 to 15 μm, still more preferably 3 to 10 μm. The upper and lower limits of the average particle size range can be arbitrarily combined.

[Activated carbon 2]
The mesopore amount V1 of the activated carbon 2 is preferably a value larger than 0.8 cc / g from the viewpoint of increasing the output characteristics when incorporated in the power storage element. On the other hand, V1 is preferably 2.5 cc / g or less from the viewpoint of suppressing a decrease in the capacity of the power storage element. The above V1 is more preferably 1.00 cc / g or more and 2.0 cc / g or less, and further preferably 1.2 cc / g or more and 1.8 cc / g or less.

On the other hand, the micropore amount V2 of the activated carbon 2 is preferably a value larger than 0.8 cc / g in order to increase the specific surface area and the capacity of the activated carbon. On the other hand, V2 is 3.0 cc / g or less, more preferably more than 1.0 cc / g and 2.5 cc / g or less, from the viewpoint of increasing the density of activated carbon as an electrode and increasing the capacity per unit volume. More preferably, it is 1.5 cc / g or more and 2.5 cc / g or less.

The activated carbon 2 having the above-mentioned mesopore amount and micropore amount has a higher BET specific surface area than the activated carbon used for a conventional electric double layer capacitor or a lithium ion capacitor. The specific value of the BET specific surface area of the activated carbon 2 is preferably 2,300 m ² / g or more and 4,000 m ² / g or less. The lower limit of the BET specific surface area is more preferably 3,000 m ² / g or more, and further preferably 3,200 m ² / g or more. On the other hand, the upper limit of the BET specific surface area is more preferably 3,800 m ² / g or less. When the BET specific surface area is 2,300 m ² / g or more, good energy density is likely to be obtained, while when the BET specific surface area is 4,000 m ² / g or less, the strength of the electrode is maintained. Since it is not necessary to add a large amount of binder, the performance per electrode volume is high.
Regarding the V1, V2 and BET specific surface areas of the activated carbon 2, the upper and lower limits of the suitable ranges described above can be arbitrarily combined.

Activated carbon 2 having the above-mentioned characteristics can be obtained, for example, by using a raw material and a treatment method as described below.
The carbon source used as a raw material for the activated charcoal 2 is not particularly limited as long as it is a carbon source normally used as a raw material for activated charcoal. Fossil-based raw materials such as phenol resin, furan resin, vinyl chloride resin, vinyl acetate resin, melamine resin, urea resin, resorcinol resin and various synthetic resins and the like can be mentioned. Among these raw materials, phenol resin and furan resin are particularly preferable because they are suitable for producing activated carbon having a high specific surface area.

Examples of the method of carbonizing these raw materials or the heating method at the time of activation treatment include known methods such as a fixed bed method, a moving bed method, a fluidized bed method, a slurry method, and a rotary kiln method. As the heating atmosphere, an inert gas such as nitrogen, carbon dioxide, helium, or argon, or a gas containing these inert gases as a main component and mixed with other gases is used. The carbonization temperature is preferably about 400 to 700 ° C. (the lower limit is preferably 450 ° C. or higher, more preferably 500 ° C. or higher, and the upper limit is preferably 650 ° C. or lower) for about 0.5 to 10 hours.

Examples of the method for activating the charcoal after the carbonization treatment include a gas activation method in which an activated gas such as steam, carbon dioxide, and oxygen is used for firing, and an alkali metal activation method in which a heat treatment is performed after mixing with an alkali metal compound. The alkali metal activation method is preferable for producing activated carbon having a high specific surface area.
In this activation method, the mixture was mixed so that the mass ratio of the carbide to the alkali metal compound such as KOH or NaOH was 1: 1 or more (the amount of the alkali metal compound was the same as or larger than the amount of the carbide). Later, it is heated in the range of 600 to 900 ° C. (preferably 650 ° C. to 850 ° C.) in an inert gas atmosphere for 0.5 to 5 hours, and then the alkali metal compound is washed and removed with acid and water, and further dried. I do.

It was mentioned earlier that the mass ratio of the charcoal to the alkali metal compound (= charcoal: alkali metal compound) is preferably 1: 1 or more. However, as the amount of the alkali metal compound increases, the amount of mesopores increases, but the mass ratio is 1: 1. Since the amount of pores tends to increase sharply around 3.5, the mass ratio is preferably 1: 3 or more, and the alkali metal compound is preferably 1: 5.5 or less. The mass ratio increases as the amount of the alkali metal compound increases, but it is preferably in the above range in consideration of the treatment efficiency such as subsequent cleaning.
In order to increase the amount of micropores and not the amount of mesopores, it is advisable to increase the amount of carbides at the time of activation and mix with KOH. In order to increase both the amount of micropores and the amount of mesopores, it is advisable to use a large amount of KOH. Further, in order to mainly increase the amount of mesopores, it is preferable to perform steam activation after performing alkali activation treatment.
The average particle size of the activated carbon 2 is preferably 2 μm or more and 20 μm or less, and more preferably 3 μm or more and 10 μm or less.

[Usage of activated carbon]
Activated carbons 1 and 2 may be one type of activated carbon, or may be a mixture of two or more types of activated carbon, and each of the above-mentioned characteristic values may be shown as a whole mixture.
The above-mentioned activated carbons 1 and 2 may be used by selecting one of them, or may be used by mixing both of them.
The positive electrode active material may contain a material other than activated carbons 1 and 2 (for example, activated carbon having no specific V ₁ and / or V ₂ or a material other than activated carbon (for example, a conductive polymer)). .. In an exemplary embodiment, the content of activated carbon 1 or the content of activated carbon 2 in the positive electrode active material layer, or the total content of activated carbons 1 and 2, that is, the weight ratio of the carbon material in the positive electrode active material layer is A ₁ . In this case, A ₁ is preferably 15% by mass or more and 65% by mass or less, and more preferably 20% by mass or more and 50% by mass or less.

[Transition metal oxide]
The transition metal oxide is preferably a transition metal oxide having a layered structure, an olivine structure, or a spinel structure.
The transition metal oxide used as the positive electrode active material is not particularly limited. Examples of transition metal oxides include oxides containing at least one element selected from the group consisting of cobalt, nickel, manganese, iron, vanadium, and chromium.

Specifically, as a transition metal oxide, for example,
Li _x1 CoO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 NiO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 Ny M ¹ (1- _{y )} O ₂ (In the formula, M ¹ is at least one element selected from the group consisting of Co, Mn, Al, Fe, Mg, and Ti, and x1 is 0. ≦ x1 ≦ 2 and y satisfies 0.2 <y <0.97),.
Li _x1 Ni _1/3 Co _1/3 Mn _1/3 O ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 MnO ₂ (in the formula, x1 satisfies 0≤x1≤2),
α-Li _x1 FeO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 VO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 CrO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 Mn ₂ O ₄ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 M ² _y Mn _(2-y) O ₄ (M ² is at least one element selected from the group consisting of Co, Ni, Al, Fe, Mg, and Ti, and x1 is 0≤x1≤. 2 and y satisfies 0.2 <y <0.97),
Li _x1 Ni _a Co _b Al _(1-ab) O ₂ (In the formula, x1 satisfies 0≤x1≤2, and a and b are 0.2 <a <0.97, 0., respectively. 2 <b <0.97),
Li _x1 Ni _c Cod Mn _{(1-c-d) O 2} (In the formula, x1 satisfies 0≤x1≤2, and c and d are 0.2 <c <0.97, 0., respectively. 2 <d <0.97),
Li _x1 M ³ PO ₄ (In the formula, M ³ is at least one element selected from the group consisting of Co, Ni, Fe, Mn, and Cu, and x1 satisfies 0≤x1≤2.) , And Li _z V ₂ (PO ₄ ) ₃ (in the equation, z satisfies 0 ≦ z ≦ 3).
Examples thereof include at least one lithium metal composite oxide selected from the group consisting of.
In the present embodiment, if the positive electrode precursor contains an alkali metal compound different from the positive electrode active material, the alkali metal compound becomes a dopant source for the alkali metal by predoping, and the negative electrode can be predoped. Therefore, lithium is previously added to the transition metal compound. Even if it does not contain ions (that is, even if x1 or z = 0 in the general formula of the transition metal oxide), it can be electrostatically charged and discharged as a non-aqueous lithium storage element.
The transition metal oxides include Li _x2 FePO ₄ (where x2 satisfies 0≤x1≤2), Li _x2 CoPO ₄ (in the equation, x2 satisfies 0≤x1≤2), and. At least one selected from the group consisting of Li _x2 MnPO ₄ (in the formula, x2 satisfies 0 ≦ x1 ≦ 2) is preferable.

The average particle size of the lithium transition metal oxide is preferably 0.1 to 20 μm.
When the average particle size is 0.1 μm or more, the capacity per electrode volume tends to be high due to the high density of the active material layer. Here, if the average particle size is small, the durability may be low, but if the average particle size is 0.1 μm or more, such a defect is unlikely to occur. On the other hand, when the average particle size is 20 μm or less, it tends to be easy to adapt to high-speed charging / discharging. The average particle size is more preferably 0.5 to 15 μm, still more preferably 1 to 10 μm. Further, it is preferable that the average particle size of the lithium transition metal oxide is smaller than the average particle size of the carbon material. If the average particle size of the lithium transition metal oxide is small, the lithium transition metal oxide can be arranged in the voids formed by the carbon material having a large average particle size, and the resistance can be reduced.

[Usage of Lithium Transition Metal Oxide]
The lithium transition metal oxide may be one kind, or may be a mixture of two or more kinds of materials, and each of the above-mentioned characteristic values may be shown as a whole mixture.
The positive electrode active material may contain a material other than the above-mentioned lithium transition metal oxide (for example, a conductive polymer or the like). In an exemplary embodiment, when the content ratio of the lithium transition metal oxide is G ₁ with reference to the total weight of the positive electrode active material layer, G ₁ is 1% by weight or more and 50% by weight or less, preferably 10% by weight. % Or more and 45% by weight or less, more preferably 15% by weight or more and 40% by weight or less. When the content ratio of the transition metal oxide is 1% by weight or more, the energy density of the power storage element can be further increased, and when the content ratio is 50% by weight or less, the power storage element can be increased in output. can.

[Usage of positive electrode active material]
When the weight ratio of the carbon material in the positive electrode active material layer is A ₁ and the weight ratio of the lithium transition metal oxide is A ₂ , the content A ₂ of the lithium transition metal oxide and the carbon material It is preferable that the ratio A ₂ / A _{1 to the content A 1 is} 0.1 or more and 2.0 or less. More preferably, it is 0.2 or more and 1.2 or less. When A ₂ / A ₁ is 0.1 or more, the bulk density of the positive electrode active material layer can be increased and the capacity can be increased. When A ₂ / A ₁ is 2.0 or less, the resistance can be lowered because the electron conduction between the activated carbons is increased, and the contact area between the activated carbon and the alkali metal compound can be increased, so that the decomposition of the alkali metal compound can be promoted.

The content ratio of the positive electrode active material in the positive electrode active material layer is preferably 35% by mass or more and 95% by mass or less based on the total mass of the positive electrode active material layer in the positive electrode precursor. The upper limit of the content ratio of the positive electrode active material is more preferably 45% by mass or more, further preferably 55% by mass or more. On the other hand, the lower limit of the content ratio of the positive electrode active material is more preferably 90% by mass or less, further preferably 80% by mass or less. By setting the content ratio in this range, suitable charge / discharge characteristics are exhibited.

[Lithium compound]
It is preferable that the positive electrode active material layer of the positive electrode precursor of the present embodiment contains a lithium compound other than the positive electrode active material. Further, it is preferable that the positive electrode active material layer of the positive electrode of the present embodiment contains a lithium compound other than the positive electrode active material.
Examples of the lithium compound in the present embodiment include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, lithium oxide, lithium hydroxide, lithium fluoride, lithium chloride, lithium oxalate, lithium iodide, lithium nitride, and shu. One or more selected from lithium acid and lithium acetate are preferably used. Among them, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate are more preferable, and lithium carbonate is more preferably used from the viewpoint that it can be handled in the air and has low hygroscopicity. Such a lithium compound decomposes when a voltage is applied, functions as a dopant source for lithium doping to the negative electrode, and forms pores in the positive electrode active material layer, so that the electrolytic solution has excellent retention and ionic conductivity. It is possible to form an excellent positive electrode. When an electrolytic solution in which a lithium salt such as LiPF ₆ described later is dissolved in advance is used as the non-aqueous electrolytic solution, the alkali metal carbonate can also be used alone. The lithium compound contained in the positive electrode precursor may be one kind, may contain two or more kinds of lithium compounds, or may be used as a mixture of the lithium compound and another alkali metal carbonate.

Further, the positive electrode precursor of the present embodiment may contain at least one lithium compound, and in addition to the lithium compound, M in the following formula may be one or more selected from Na, K, Rb, and Cs. ,
Oxides such as _M2O ,
Hydroxides such as MOH,
Halides such as MF and MCl,
M ₂ (CO ₂ ) _2nd grade oxalate,
It may contain one or more carboxylates such as RCOM (in the formula, R is an H, an alkyl group, or an aryl group).
The positive electrode precursor is an alkaline earth metal carbonate selected from BeCO ₃ , MgCO ₃ , CaCO ₃ , SrCO ₃ , or BaCO ₃ , as well as an alkaline earth metal oxide, an alkaline earth metal hydroxide, and an alkaline soil. It may contain one or more kinds of metal halides, alkaline earth metal oxalates, and alkaline earth metal carboxylates.

It is preferable to prepare the positive electrode precursor so that the weight ratio of the alkali metal compound contained in the positive electrode precursor is 10% by mass or more and 50% by mass or less. If it is 10% by mass or more, a sufficient amount of alkali metal ions can be pre-doped into the negative electrode, and the capacity of the non-aqueous lithium storage element is increased. When it is 50% by mass or less, the electron conduction in the positive electrode precursor can be enhanced, so that the alkali metal compound can be efficiently decomposed.
When the positive electrode precursor contains the above two or more kinds of alkali metal compounds or alkaline earth metal compounds in addition to the lithium metal compound, the total amount of the alkali metal compound and the alkaline earth metal compound is one side of the positive electrode precursor. It is preferable to prepare the positive electrode precursor so that it is contained in the positive electrode active material layer in a proportion of 1% by mass or more and 50% by mass or less.

[Lithium compound of positive electrode precursor]
The lithium compound is preferably in the form of particles. The average particle size of the lithium compound contained in the positive electrode precursor is preferably 0.1 μm or more and 100 μm or less. The upper limit of the average particle size of the lithium compound contained in the positive electrode precursor is more preferably 50 μm or less, further preferably 20 μm or less, and most preferably 10 μm or less. On the other hand, the lower limit of the average particle size of the lithium compound contained in the positive electrode precursor is more preferably 0.3 μm or more, further preferably 0.5 μm or more. When the average particle size of the lithium compound is 0.1 μm or more, the pores remaining after the oxidation reaction of the lithium compound in the positive electrode have a sufficient volume to hold the electrolytic solution, so that the high load charge / discharge characteristics are exhibited. improves. When the average particle size of the lithium compound is 100 μm or less, the surface area of the lithium compound does not become excessively small, so that the rate of the oxidation reaction of the lithium compound can be ensured. The upper and lower limits of the range of the average particle size of the lithium compound can be arbitrarily combined.

For pulverizing the lithium compound, any wet and / or dry pulverizer such as a ball mill, a bead mill, a ring mill, a jet mill, a rod mill, a high pressure homogenizer, etc. can be used. In wet pulverization in which a lithium compound is dispersed in a dispersion medium and pulverized using the dispersion liquid, the dispersion medium can be volatilized with a heating mixer or the like as necessary after pulverization to pulverize the lithium compound. Further, for the nuclear growth of the lithium compound, a CVD method; a PVD method using thermal plasma, laser absorption, or the like; a liquid phase process such as precipitation, coprecipitation, precipitation, or positive deposition can be used. Further, a plurality of the above methods may be combined as needed.

[Lithium compound of positive electrode]
The positive electrode preferably contains a lithium compound other than the positive electrode active material. In the present invention, when the _average particle size of the lithium compound other than the positive electrode active material contained in the positive electrode is X1, it is preferably 0.1 μm ≦ X1 ≦ 10.0 μm. A more preferable range of the average particle size of the lithium compound is 0.5 μm ≦ X ₁ ≦ 5.0 μm. When X ₁ is 0.1 μm or more, the high load charge / discharge cycle characteristics are improved by adsorbing the fluorine ions generated in the high load charge / discharge cycle. When X ₁ is 10.0 μm or less, the reaction area with the fluorine ions generated in the high load charge / discharge cycle increases, so that the adsorption of the fluorine ions can be efficiently performed.

The lithium compound contained in the positive electrode other than the positive electrode active material is characterized by being 1% by mass or more and 50% by mass or less based on the total mass of the positive electrode active material layer in the positive electrode, and is 2.5% by mass or more and 25% by mass. % Or less is more preferable. When the amount of the lithium compound is 1% by mass or more, lithium carbonate suppresses the decomposition reaction of the electrolytic solution solvent on the positive electrode in a high temperature environment, so that the high temperature durability is improved, and the effect is improved when the amount is 2.5% by mass or more. Becomes noticeable. Further, when the amount of the lithium compound is 50% by mass or less, the electron conductivity between the positive electrode active materials is relatively small to be hindered by the lithium compound, so that it exhibits high input / output characteristics and is 35% by mass or less. , Especially preferable from the viewpoint of input / output characteristics. The combination of the lower limit and the upper limit can be arbitrary.

[Method for identifying lithium compounds in electrodes]
The method for identifying the lithium compound contained in the positive electrode is not particularly limited, but can be identified by, for example, the following method. For the identification of the lithium compound, it is preferable to identify by combining a plurality of analysis methods described below.
When measuring SEM-EDX, Raman, and XPS described below, the non-aqueous lithium storage element may be disassembled in an argon box, the positive electrode may be taken out, and the electrolyte adhering to the positive electrode surface may be washed before the measurement. preferable. As for the method for cleaning the positive electrode, a carbonate solvent such as dimethyl carbonate, ethylmethyl carbonate, or diethyl carbonate can be preferably used because the electrolyte adhering to the surface of the positive electrode may be washed away. As a cleaning method, for example, the positive electrode is immersed in a diethyl carbonate solvent having a weight of 50 to 100 times the positive electrode for 10 minutes or more, and then the solvent is replaced and the positive electrode is immersed again. The positive electrode is then removed from diethyl carbonate, vacuum dried, and then analyzed for SEM-EDX, Raman spectroscopy, and XPS. The conditions for vacuum drying are such that the residual diethyl carbonate in the positive electrode is 1% by mass or less in the range of temperature: 0 to 200 ° C., pressure: 0 to 20 kPa, and time: 1 to 40 hours. The residual amount of diethyl carbonate can be quantified based on a calibration curve prepared in advance by measuring the GC / MS of the water after washing with distilled water and adjusting the liquid amount, which will be described later.
In ion chromatography described later, anions can be identified by analyzing the water after washing the positive electrode with distilled water.
If the lithium compound cannot be identified by the analytical method, other analytical methods include ⁷ Li-solid NMR, XRD (X-ray diffraction), TOF-SIMS (time-of-flight secondary ion mass spectrometry), and AES (Auger electron). Lithium compounds can also be identified by using spectroscopic), TPD / MS (mass spectrometry of heated gas), DSC (differential scanning calorimeter analysis) and the like.

[Scanning Electron Microscope-Energy Dispersive X-ray Analysis (SEM-EDX)]
The lithium compound and the positive electrode active material can be identified by oxygen mapping using an SEM-EDX image of the positive electrode surface measured at an observation magnification of 1000 to 4000 times. As a measurement example of the SEM-EDX image, the acceleration voltage can be measured as 10 kV, the emission current as 1 μA, the number of measurement pixels as 256 × 256 pixels, and the number of integrations as 50 times. In order to prevent the sample from being charged, gold, platinum, osmium or the like can be surface-treated by a method such as vacuum vapor deposition or sputtering. Regarding the measurement method of the SEM-EDX image, it is preferable to adjust the brightness and the contrast so that the brightness does not reach the maximum brightness and the average value of the brightness is in the range of 40% to 60%. When the obtained oxygen mapping is binarized based on the average value of brightness, the particles containing 50% or more of the bright part in area are defined as lithium compounds.

[Microscopic Raman spectroscopy]
The lithium carbonate and the positive electrode active material can be discriminated by Raman imaging of carbonate ions on the surface of the positive electrode precursor measured at an observation magnification of 1000 to 4000 times. As an example of measurement conditions, the excitation light is 532 nm, the excitation light intensity is 1%, the long operation of the objective lens is 50 times, the diffraction lattice is 1800 gr / mm, the mapping method is point scanning (slit 65 mm, binning 5 fix), 1 mm step, The exposure time per point can be measured for 3 seconds, the number of integrations can be measured once, and the measurement can be performed under the condition of having a noise filter. For the measured Raman spectrum, a straight baseline is set in the range of 1071 to 1104 cm ^-1 , the area is calculated with a positive value from the baseline as the peak of carbonate ion, and the frequency is integrated. At this time, the noise component is added. The frequency for the carbonate ion peak area approximated by the Gaussian function is subtracted from the carbonate ion frequency distribution.

[X-ray Photoelectron spectroscopy (XPS)]
The bonding state of the lithium compound can be determined by analyzing the electronic state by XPS. As an example of measurement conditions, the X-ray source is monochromatic AlKα, the X-ray beam diameter is 100 μmφ (25 W, 15 kV), the path energy is narrow scan: 58.70 eV, there is charge neutralization, and the number of sweeps is narrow scan: 10 times. (Carbon, oxygen) 20 times (fluorine) 30 times (phosphorus) 40 times (lithium element) 50 times (silicon), energy step can be measured under the condition of narrow scan: 0.25 eV. It is preferable to clean the surface of the positive electrode by sputtering before measuring XPS. As a sputtering condition, for example, the surface of the positive electrode can be cleaned under the condition of an acceleration voltage of 1.0 kV and a range of 2 mm × 2 mm for 1 minute (1.25 nm / min in terms of SiO ₂ ).
About the obtained XPS spectrum
The peaks of the binding energy of Li1s of 50 to 54 eV are LiO ₂ or Li—C bonds, and the peaks of 55 to 60 eV are LiF, Li ₂ CO ₃ , and Li _x PO yF _z (where x, _y , and z are, respectively). It is an integer from 1 to 6);
The peak of C1s binding energy 285eV is CC-bonded, the peak of 286eV is CO _- bonded, the peak of 288eV is COO, and the peak of 290-292eV is ^CO3-2- , CF-bonded;
The peaks of the binding energy of O1s of 527 to 530 eV are O ^2- (Li ₂ O), and the peaks of 513 to 532 eV are CO, CO ₃ , OH, PO _x (x is an integer of 1 to 4 in the formula), SiO. _x (in the formula, x is an integer of 1 to 4), the peak of 533 eV is CO, SiO _x (in the formula, x is an integer of 1 to 4);
The peak of the binding energy 685 eV of F1s is LiF, the peak of 687 eV is CF bond, Li _x PO _y F _z (in the formula, x, y, and z are integers of 1 to 6, respectively) ^, PF _6- . ;
Regarding the binding energy of P2p, the peak of 133 eV is PO _x (in the formula, x is an integer of 1 to 4), and the peak of 134 to 136 eV is PF _x (in the formula, x is an integer of 1 to 6);
The peak of the binding energy 99eV of Si2p is Si, silicide, and the peak of 101 to 107eV is Si _x Oy (in the formula, x and _y are arbitrary integers, respectively).
Can be attributed as.
When the peaks of the obtained spectra overlap, it is preferable to separate the peaks assuming a Gaussian function or a Lorentz function and assign the spectra. The existing lithium compound can be identified from the obtained electronic state measurement results and the existing element ratio results.

[Ion chromatography]
By washing the positive electrode precursor with distilled water and analyzing the washed water by ion chromatography, the carbonate ion eluted in the water can be identified. As the column to be used, an ion exchange type, an ion exclusion type, and a reverse phase ion pair type can be used. As the detector, an electric conductivity detector, an ultraviolet visible absorptiometry detector, an electrochemical detector, etc. can be used, and a suppressor method in which a suppressor is installed in front of the detector, or electricity without a suppressor. A non-suppressor method using a solution having low conductivity as an eluent can be used. It is also possible to measure by combining a mass spectrometer or a charged particle detector with a detector.
The retention time of the sample is constant for each ion species component if conditions such as the column or eluent to be used are determined, and the magnitude of the peak response differs for each ion species, but is proportional to the concentration of the ion species. .. By measuring in advance a standard solution with a known concentration that ensures traceability, it is possible to qualify and quantify the ionic species component.

If the lithium compound cannot be identified by the above method, other analysis methods include solid ⁷ Li-NMR, XRD (X-ray diffraction), TOF-SIMS (time-of-flight secondary ion mass spectrometry), and AES (Auger electron spectroscopy). ), TPD / MS (mass spectrometry of heated gas), DSC (differential scanning calorimeter analysis) and the like can also be used to identify the lithium compound.

[Lithium compound quantification method]
The method for quantifying the lithium compound contained in the positive electrode is described below.
The positive electrode can be washed with an organic solvent and then with distilled water, and the lithium compound can be quantified from the change in the mass of the positive electrode before and after washing with distilled water. The area of the positive electrode to be measured is not particularly limited, but is preferably 5 cm ² or more and 200 cm ² or less, and more preferably 25 cm ² or more and 150 cm ² or less, from the viewpoint of reducing variations in measurement. If the area is 5 cm ² or more, the reproducibility of the measurement is ensured. If the area is 200 cm ² or less, the handling of the sample is excellent. The cleaning with an organic solvent is not particularly limited as long as it can remove the non-aqueous electrolyte decomposition product deposited on the surface of the positive electrode, but the lithium compound can be washed by using an organic solvent having a solubility of 2% or less. It is preferable because the elution of the solvent is suppressed. For example, polar solvents such as methanol and acetone are preferably used.

As for the method of cleaning the positive electrode, the positive electrode is sufficiently immersed in a methanol solution 50 to 100 times the mass of the positive electrode for 3 days or more. At this time, it is preferable to take measures such as covering the container so that methanol does not volatilize. After that, the positive electrode is taken out from methanol and vacuum dried (temperature: 100 to 200 ° C., pressure: 0 to 10 kPa, time: 5 to 20 hours, and the condition is that the residual amount of methanol in the positive electrode is 1% by mass or less. The residual amount of the above can be quantified by measuring the GC / MS of the water after washing with distilled water, which will be described later, based on the calibration line prepared in advance.), And the mass of the positive electrode at that time is M ₀ (g). And. Subsequently, the positive electrode is sufficiently immersed in distilled water having 100 times the mass of the positive electrode (100M ₀ (g)) for 3 days or more. At this time, it is preferable to take measures such as covering the container so that the distilled water does not volatilize. After soaking for 3 days or more, the positive electrode is taken out from the distilled water (in the case of measuring the above-mentioned ion chromatography, the amount of the liquid is adjusted so that the amount of the distilled water becomes 100M ₀ (g)), and the above-mentioned. Vacuum dry as in methanol washing. The mass of the positive electrode at this time is M ₁ (g), and subsequently, in order to measure the mass of the obtained positive electrode current collector, a spatula, a brush, a brush, or the like is used to measure the positive electrode active material layer on the current collector. Get rid of. Assuming that the mass of the obtained positive electrode current collector is M ₂ (g), the proportion Z (mass%) of the lithium compound contained in the positive electrode can be calculated by the following equation.
Z = 100 × [1- (M ₁ -M ₂ ) / (M ₀ -M ₂ )]

[Average particle size of lithium compound and positive electrode active material]
When the average particle size of the lithium compound is X ₁ , 0.1 μm ≤ X ₁ ≤ 10 μm, and when the average particle size of the positive electrode active material is Y ₁ , 2 μm ≤ Y ₁ ≤ 20 μm, and X ₁ <Y ₁ is preferable. More preferably, X ₁ is 0.5 μm ≤ X ₁ ≤ 5 μm, and Y ₁ is 3 μm ≤ Y ₁ ≤ 10 μm. When X ₁ is 0.1 μm or more, the lithium compound can remain in the positive electrode after lithium predoping. Therefore, the durability of the high load charge / discharge cycle is achieved by adsorbing the fluorine ions generated in the high load charge / discharge cycle. Is improved. On the other hand, when X ₁ is 10 μm or less, the reaction area with the fluorine ions generated in the high load charge / discharge cycle increases, so that the adsorption of the fluorine ions can be efficiently performed. When Y ₁ is 2 μm or more, electron conductivity between the positive electrode active materials can be ensured. On the other hand, when Y ₁ is 20 μm or less, high input / output characteristics can be obtained because the reaction area with the electrolyte ion increases. When X ₁ <Y ₁ , the lithium compound is filled in the gaps formed between the positive electrode active materials, so that the energy density can be increased while ensuring the electron conductivity between the positive electrode active materials.
The measuring method of X ₁ and Y ₁ is not particularly limited, but can be calculated from the SEM image of the positive electrode cross section and the SEM-EDX image. As a method for forming the positive electrode cross section, BIB processing can be used in which an Ar beam is irradiated from the upper part of the positive electrode to form a smooth cross section along the end portion of the shielding plate installed directly above the sample. When lithium carbonate is contained in the positive electrode, the distribution of carbonate ions can be obtained by measuring Raman imaging of the cross section of the positive electrode.

[Method of distinguishing between lithium compound and positive electrode active material]
The lithium compound and the positive electrode active material can be identified by oxygen mapping using an SEM-EDX image of the positive electrode cross section measured at an observation magnification of 1000 to 4000 times. Regarding the measurement method of the SEM-EDX image, it is preferable to adjust the brightness and the contrast so that the brightness does not reach the maximum brightness and the average value of the brightness is in the range of 40% to 60%. Particles containing 50% or more of the bright part binarized with respect to the obtained oxygen mapping based on the average value of brightness are defined as lithium compounds.

[Calculation method of X ₁ and Y ₁ ]
X ₁ and Y ₁ can be obtained by image analysis of images obtained from the positive electrode cross section SEM-EDX measured in the same field as the positive electrode cross section SEM. The lithium compound particles X and the other particles identified in the SEM image of the positive electrode cross section are defined as the positive electrode active material particles Y, and the cross-sectional area S is obtained for all the X and Y particles observed in the cross-sectional SEM image. Is obtained, and the particle diameter d is obtained by the following equation (the circumference ratio is π).
d = 2 × (S / π) ^1/2
Using the obtained particle size d, the volume average particle size X ₀ and Y ₀ are obtained by the following equation.
X ₀ (Y ₀ ) = Σ [4 / 3π × (d / 2) ³ × d] / Σ [4 / 3π × (d / 2) ³ ]
Measure at 5 or more points by changing the field of view of the positive electrode cross section, and take the average value of X ₀ and Y ₀ , respectively, as the average particle diameter X ₁ and Y ₁ .

[Arbitrary component of positive electrode active material layer]
If necessary, the positive electrode active material layer in the present embodiment may contain optional components such as a conductive filler, a binder, and a dispersion stabilizer in addition to the positive electrode active material and the lithium compound.
The conductive filler is not particularly limited, and for example, acetylene black, ketjen black, vapor-grown carbon fiber, graphite, carbon nanotubes, a mixture thereof, and the like can be used. The amount of the conductive filler used is preferably 0 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the positive electrode active material. It is more preferably 0.01 parts by mass or more and 20 parts by mass or less, and further preferably 1 part by mass or more and 15 parts by mass or less. If the amount of the conductive filler used is more than 30 parts by mass, the content ratio of the positive electrode active material in the positive electrode active material layer is small, and the energy density per volume of the positive electrode active material layer is lowered, which is not preferable.

The binder is not particularly limited, but for example, PVdF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), polyimide, latex, styrene-butadiene copolymer, fluororubber, acrylic copolymer and the like. Can be used. The amount of the binder used is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 27 parts by mass or less, and further preferably 5 parts by mass or more and 25 parts by mass with respect to 100 parts by mass of the positive electrode active material. It is less than a part. When the amount of the binder used is 1 part by mass or more, sufficient electrode strength is exhibited. On the other hand, when the amount of the binder used is 30 parts by mass or less, high input / output characteristics are exhibited without inhibiting the ingress / egress and diffusion of ions into the positive electrode active material.

The dispersion stabilizer is not particularly limited, but for example, PVP (polyvinylpyrrolidone), PVA (polyvinyl alcohol), a cellulose derivative and the like can be used. The amount of the dispersion stabilizer used is preferably 0 parts by mass or 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the positive electrode active material. When the amount of the dispersion stabilizer used is 10 parts by mass or less, high input / output characteristics are exhibited without inhibiting the ingress / egress and diffusion of ions into the positive electrode active material.

[Positive current collector]
The material constituting the positive electrode current collector in the present embodiment is not particularly limited as long as it has high electron conductivity and does not deteriorate due to elution into the electrolytic solution and reaction with the electrolyte or ions, but is not particularly limited. Foil is preferred. Aluminum foil is particularly preferable as the positive electrode current collector in the non-aqueous lithium storage element of the present embodiment.
The metal foil may be a normal metal leaf having no irregularities or through holes, a metal leaf having irregularities subjected to embossing, chemical etching, electrolytic precipitation, blasting, etc., expanded metal, punching metal, etc. , A metal foil having through holes such as an etching foil may be used.
In particular, from the viewpoint of ease of electrode production and high electron conductivity, the positive electrode current collector in the present embodiment is preferably non-porous. In the present specification, the “non-porous positive electrode current collector” means that lithium ions pass through the positive electrode current collector and the lithium ions are uniform on the front and back surfaces of the positive electrode, at least in the coated region of the positive electrode active material layer. It means a positive electrode current collector that does not have a hole to the extent that it becomes an ion. Therefore, within the range in which the effect of the present invention is exhibited, the positive electrode current collector having extremely small diameter or a small amount of holes and the positive electrode current collector having holes in the uncoated region of the positive electrode active material layer are also excluded. is not. Further, in the present embodiment, at least the region where the positive electrode active material layer is coated is non-porous in the positive electrode current collector, and the surplus portion of the positive electrode current collector where the positive electrode active material layer is not coated is covered. May or may not have holes.
The thickness of the positive electrode current collector is not particularly limited as long as the shape and strength of the positive electrode can be sufficiently maintained, but is preferably 1 to 100 μm, for example.

[Manufacturing of positive electrode precursor]
In the present embodiment, the positive electrode precursor to be the positive electrode of the non-aqueous lithium-type power storage element can be manufactured by a technique for manufacturing electrodes in known lithium ion batteries, electric double layer capacitors and the like. For example, a positive electrode active material, a lithium compound, and other optional components used as necessary are dispersed or dissolved in water or an organic solvent to prepare a slurry-like coating liquid, and this coating liquid is collected as a positive electrode. A positive electrode precursor can be obtained by applying a coating film on one or both sides of an electric body to form a coating film and drying the coating film. Further, the obtained positive electrode precursor may be pressed to adjust the film thickness or bulk density of the positive electrode active material layer. Alternatively, without the use of solvents, the positive electrode active material and lithium compound, as well as other optional components used as needed, are dry mixed, the resulting mixture is press molded and then conductively bonded. It is also possible to attach the agent to the positive electrode current collector.

The coating liquid of the positive electrode precursor is a dry blend of a part or all of various material powders including a positive electrode active material, and then water or an organic solvent and / or a binder or a dispersion stabilizer is dissolved or dispersed in them. The liquid or slurry-like substance may be added and prepared. Further, various material powders containing a positive electrode active material may be added to a liquid or slurry-like substance in which a binder or a dispersion stabilizer is dissolved or dispersed in water or an organic solvent to prepare a coating liquid. good. As the method of dry blending, for example, a positive electrode active material and a lithium compound are premixed using a ball mill or the like, and if necessary, a conductive filler is premixed so that the lithium compound having low conductivity is coated with the conductive filler. You may do. This facilitates the decomposition of the lithium compound in the positive electrode precursor in the lithium doping step described later. When water is used as the solvent of the coating liquid, the coating liquid may become alkaline by adding the lithium compound, so a pH adjuster may be added if necessary.

The preparation of the coating liquid for the positive electrode precursor is not particularly limited, but preferably a homodisper or a multi-axis disperser, a planetary mixer, a disperser such as a thin film swirling high-speed mixer or the like is used. Can be done. In order to obtain a coating liquid in a good dispersed state, it is preferable to disperse at a peripheral speed of 1 m / s or more and 50 m / s or less. When the peripheral speed is 1 m / s or more, it is preferable because various materials are satisfactorily dissolved or dispersed. Further, when the peripheral speed is 50 m / s or less, various materials are not destroyed by heat or shearing force due to dispersion, and reaggregation does not occur, which is preferable.
The dispersity of the coating liquid is preferably such that the particle size measured by the grain gauge is 0.1 μm or more and 100 μm or less. The upper limit of the dispersity is more preferably 80 μm or less in particle size, and further preferably 50 μm or less in particle size. If the particle size is less than 0.1 μm, the size is smaller than the particle size of various material powders containing the positive electrode active material, and the material is crushed at the time of preparing the coating liquid, which is not preferable. Further, when the particle size is 100 μm or less, stable coating can be performed without clogging at the time of discharging the coating liquid or generation of streaks on the coating film.

The viscosity (ηb) of the coating liquid of the positive electrode precursor is preferably 1,000 mPa · s or more and 20,000 mPa · s or less, more preferably 1,500 mPa · s or more and 10,000 mPa · s or less, still more preferably 1. , 700 mPa · s or more and 5,000 mPa · s or less. When the viscosity (ηb) is 1,000 mPa · s or more, liquid dripping during formation of the coating film is suppressed, and the width and film thickness of the coating film can be satisfactorily controlled. Further, when the viscosity (ηb) is 20,000 mPa · s or less, the pressure loss in the flow path of the coating liquid when using the coating machine is small and stable coating can be performed, and the coating film thickness is less than the desired thickness. Can be controlled.
The TI value (thixotropy index value) of the coating liquid is preferably 1.1 or more, more preferably 1.2 or more, and further preferably 1.5 or more. When the TI value is 1.1 or more, the coating film width and the film thickness can be satisfactorily controlled.

The formation of the coating film of the positive electrode precursor is not particularly limited, but a coating machine such as a die coater or a comma coater, a knife coater, or a gravure coating machine can be preferably used. The coating film may be formed by a single-layer coating or a multi-layer coating. In the case of multi-layer coating, the coating liquid composition may be adjusted so that the content of the lithium compound in each layer of the coating film is different. The coating speed is preferably 0.1 m / min or more and 100 m / min or less, more preferably 0.5 m / min or more and 70 m / min or less, and further preferably 1 m / min or more and 50 m / min or less. If the coating speed is 0.1 m / min or more, stable coating can be performed. On the other hand, if the coating speed is 100 m / min or less, sufficient coating accuracy can be ensured.

[Primary drying]
The coating film of the positive electrode precursor is preferably dried by a drying method such as hot air drying or infrared (IR) drying, and more preferably far infrared rays, near infrared rays, or hot air at 50 ° C. or higher. The coating film may be dried at a single temperature, or may be dried at different temperatures in multiple stages. Moreover, you may dry by combining a plurality of drying methods. The drying temperature is preferably 25 ° C. or higher and 200 ° C. or lower, more preferably 40 ° C. or higher and 180 ° C. or lower, and further preferably 50 ° C. or higher and 160 ° C. or lower. When the drying temperature is 25 ° C. or higher, the solvent in the coating film can be sufficiently volatilized. On the other hand, when the drying temperature is 200 ° C. or lower, it is possible to suppress cracking of the coating film due to rapid volatilization of the solvent, uneven distribution of the binder due to migration, and oxidation of the positive electrode current collector or the positive electrode active material layer.
The water content in the positive electrode precursor after the primary drying is preferably 1% or more and 10% or less, with the mass of the positive electrode active material layer as 100%. When the water content is 1% or more, cracking of the positive electrode precursor due to excessive drying can be suppressed and the resistance can be lowered. When the water content is 10% or less, the deactivation of alkali metal ions in the non-aqueous lithium storage element can be suppressed and the energy density can be increased.
The water content contained in the positive electrode precursor can be measured, for example, by the Karl Fischer titration method (JIS 0068 (2001) “Method for measuring water content of chemical products”).

[press]
A press machine such as a hydraulic press machine or a vacuum press machine can be preferably used for pressing the positive electrode precursor. The film thickness, bulk density and electrode strength of the positive electrode active material layer can be adjusted by the press pressure described later, the gap between the press rolls, and the surface temperature of the press portion. The press pressure is preferably 0.5 kN / cm or more and 20 kN / cm or less, more preferably 1 kN / cm or more and 10 kN / cm or less, and further preferably 2 kN / cm or more and 7 kN / cm or less. When the press pressure is 0.5 kN / cm or more, the electrode strength can be sufficiently increased. On the other hand, when the press pressure is 20 kN / cm or less, the positive electrode precursor does not bend or wrinkle, and the desired positive electrode active material layer film thickness or bulk density can be adjusted. Further, the gap between the press rolls can be set to an arbitrary value according to the film thickness of the positive electrode precursor after drying so as to have a desired film thickness or bulk density of the positive electrode active material layer. Further, the pressing speed can be set to any speed at which the positive electrode precursor does not bend or wrinkle. Further, the surface temperature of the pressed portion may be room temperature or may be heated if necessary.
The lower limit of the surface temperature of the pressed portion in the case of heating is preferably the melting point of the binder of -60 ° C or higher, more preferably the melting point of the binder of -40 ° C or higher, and further preferably the melting point of the binder of -30 ° C or higher. Is. On the other hand, the upper limit of the surface temperature of the pressed portion when heating is preferably preferably the melting point of the binder to be used plus 50 ° C. or lower, more preferably the melting point of the binder plus 30 ° C. or lower, and further preferably the melting point of the binder plus. It is 20 ° C. or lower. For example, when PVdF (polyvinylidene fluoride: melting point 150 ° C.) is used as the binder, it is preferable to heat it to 90 ° C. or higher and 200 ° C. or lower, more preferably 105 ° C. or higher and 180 ° C. or lower, and further preferably 120 ° C. or higher. It is to heat to 170 ° C. or lower. The melting point of the binder can be determined from the endothermic peak position of DSC (Differential Scanning Calorimetry). For example, using a differential scanning calorimeter "DSC7" manufactured by PerkinElmer, 10 mg of sample resin is set in a measurement cell, and the temperature rises from 30 ° C. to 250 ° C. at a heating rate of 10 ° C./min in a nitrogen gas atmosphere. When the temperature is raised, the heat absorption peak temperature in the temperature raising process becomes the melting point.
Further, the press may be performed a plurality of times while changing the conditions of the press pressure, the gap, the speed, and the surface temperature of the press portion.

[Secondary drying]
The coating film of the positive electrode precursor is preferably dried by using a drying method such as vacuum drying, hot air drying, and infrared (IR) drying. The coating film may be dried at a single temperature, or may be dried at different temperatures in multiple stages. Moreover, you may dry by combining a plurality of drying methods. The drying temperature is preferably 160 ° C. or higher and 250 ° C. or lower, and more preferably 180 ° C. or higher and 240 ° C. or lower. The purpose of the secondary drying is to dry the dispersion medium or the moisture in the air that has absorbed moisture that remains without being completely volatilized in the primary drying. The dispersion medium contained in the dried positive electrode precursor is preferably 0.01% or more and 3% or less with the mass of the positive electrode active material layer as 100%. When the dispersion medium is 0.01% or more, deterioration of the binder due to excessive drying can be suppressed and the resistance can be lowered. When the dispersion medium is 3% or less, the deactivation of alkali metal ions in the non-aqueous lithium storage element can be suppressed and the capacity can be increased. After the secondary drying, it is preferable to store in an environment with a dew point of −30 ° C. or lower.

[Process sequence of drying and pressing]
The above-mentioned production of the positive electrode precursor is preferably carried out in the order of [primary drying] → [press] → [secondary drying], and after the primary drying, the binder sufficiently provides a dispersion medium. Since it is contained, it has high flexibility, suppresses structural destruction of the binder by pressing, and ensures conductivity between active materials. Therefore, the amount of the sulfur compound formed in the positive electrode active material layer is made uniform, and high output is possible.
More preferably, it is carried out in the order of [primary drying] → [secondary drying] → [pressing], and by performing the pressing last, the increase in the film thickness of the positive electrode precursor due to the secondary drying is suppressed. The swelling and contraction during charging and discharging is alleviated. Therefore, the high temperature durability can be improved by increasing the stability of the sulfur compound formed in the positive electrode active material layer. In addition, by optimizing the press conditions, structural destruction of the binder is suppressed and the output is increased.
Further, [primary drying] and [secondary drying] can be integrated as long as the peel strength of the positive electrode precursor is not lowered and cracks do not occur.

The texture of the positive electrode active material layer is preferably 20 g · m ^{-2 or more and 150 g · m -2 or} less per one side of the positive electrode current collector, and more preferably 25 g · m ^-2 or more and 120 g · m ^-2 per one side. It is less than or equal to, and more preferably 30 g · m ^-2 or more and 80 g · m ^-2 or less. If the basis weight is 20 g · m ^-2 or more, a sufficient charge / discharge capacity can be developed. On the other hand, if the basis weight is 150 g · m ^-2 or less, the ion diffusion resistance in the electrode can be kept low. Therefore, sufficient output characteristics can be obtained, and the cell volume can be reduced, so that the energy density can be increased. The upper and lower limits of the basis weight range of the positive electrode active material layer can be arbitrarily combined.

The film thickness of the positive electrode active material layer is preferably 20 μm or more and 200 μm or less per one side of the positive electrode current collector, more preferably 25 μm or more and 140 μm or less per one side, and further preferably 30 μm or more and 100 μm or less. When this film thickness is 20 μm or more, a sufficient charge / discharge capacity can be developed. On the other hand, when this film thickness is 200 μm or less, the ion diffusion resistance in the electrode can be kept low. Therefore, sufficient output characteristics can be obtained, and the cell volume can be reduced, so that the energy density can be increased. The upper and lower limits of the film thickness range of the positive electrode active material layer can be arbitrarily combined. The film thickness of the positive electrode active material layer when the current collector has through holes or irregularities means the average value of the film thickness per surface of the portion of the current collector that does not have through holes or irregularities.

[Positive electrode]
The bulk density of the positive electrode active material layer in the positive electrode after the lithium doping step described later is preferably 0.25 g / cm ³ or more, more preferably 0.30 g / cm ³ or more and 1.3 g / cm ³ or less. Is. When the bulk density of the positive electrode active material layer is 0.25 g / cm ³ or more, a high energy density can be exhibited and the miniaturization of the power storage element can be achieved. On the other hand, when the bulk density is 1.3 g / cm ³ or less, the electrolytic solution is sufficiently diffused in the pores in the positive electrode active material layer, and high output characteristics can be obtained.

[Carbon material in positive electrode active material layer, lithium transition metal oxide]
When the weight ratio of the carbon material contained in the positive electrode active material layer is A ₁ , the weight ratio of the lithium transition metal oxide is A ₂ , and the weight ratio of other components is A ₃ , the method for quantifying these values is particularly effective. Although not limited, it can be quantified by, for example, the following method.
The area of the positive electrode to be measured is not particularly limited, but is preferably 5 cm ² or more and 200 cm ² or less, and more preferably 25 cm ² or more and 150 cm ² or less, from the viewpoint of reducing variations in measurement. If the area is 5 cm ² or more, the reproducibility of the measurement is ensured. If the area is 200 cm ² or less, the handling of the sample is excellent.
First, the non-aqueous lithium-type power storage element is disassembled in an Ar box installed in a room at 23 ° C. and controlled at a dew point of −90 ° C. or lower and an oxygen concentration of 1 ppm or less, and the positive electrode is taken out. The removed positive electrode is immersed and washed with dimethyl carbonate (DMC), and then vacuum dried in a side box while maintaining no exposure to the atmosphere. The weight (M ₀ ) of the positive electrode obtained after vacuum drying is measured. Subsequently, the mixture is immersed in distilled water having a weight of 100 to 150 times the weight of the positive electrode for 3 days or more to elute components other than the carbon material and the lithium transition metal oxide into the water. It is preferable to cover the container so that the distilled water does not volatilize during the immersion. After soaking for 3 days or more, the positive electrode is taken out from the distilled water and vacuum dried in the same manner as above. The weight (M ₁ ) of the obtained positive electrode is measured. Subsequently, the positive electrode active material layer applied to one side or both sides of the positive electrode current collector is removed using a spatula, a brush, a brush, or the like. The weight (M ₂ ) of the remaining positive electrode current collector is measured, and A ₃ is calculated by the following equation (1).
A ₃ = (M ₀ -M ₁ ) / (M ₀ -M ₂ ) × 100 (1) Equation Next, in order to calculate A ₁ and A ₂ , the positive electrode active material obtained by removing the above alkali metal compound. For the layer, the TG curve is measured under the following conditions.
・ Sample pan: Platinum ・ Gas: Atmospheric atmosphere or compressed air ・ Temperature rise rate: 0.5 ° C / min or less ・ Temperature range: 25 ° C to 500 ° C or more The mass of the obtained TG curve at 25 ° C. is defined as M3 _, and the mass at the initial temperature at which the mass reduction rate becomes _M3 × 0.01 / min or less at a temperature of 500 ° C. or higher is defined as _M4 .
All carbon materials are oxidized and burned by heating at a temperature of 500 ° C. or lower in an oxygen-containing atmosphere (for example, an atmospheric atmosphere). On the other hand, the mass of the lithium transition metal oxide does not decrease up to the temperature of minus 50 ° C., which is the melting point of the lithium transition metal oxide, even in an oxygen-containing atmosphere.
Therefore, the content A2 of the lithium transition metal oxide in the positive electrode active material layer can be calculated by the following equation ( ₂ ).
A ₂ = (M ₄ / M ₃ ) x {1- (M ₀ -M ₁ ) / (M ₀ -M ₂ )} x 100 (2) formula The content of carbon material in the positive electrode active material layer A ₁ Can be calculated by the following equation (3).
A ₁ = {(M ₃ -M ₄ ) / M ₃ } x {1- (M ₀ -M ₁ ) / (M ₀ -M ₂ )} x 100 (3)

[Negative electrode]
The negative electrode has a negative electrode current collector and a negative electrode active material layer existing on one side or both sides thereof.

[Negative electrode active material layer]
The negative electrode active material layer contains a negative electrode active material that can occlude and release lithium ions. In addition to this, if necessary, an optional component such as a conductive filler, a binder, and a dispersion stabilizer may be contained.

[Negative electrode active material]
As the negative electrode active material, a substance capable of storing and releasing lithium ions can be used. Specific examples thereof include carbon materials, titanium oxides, silicon, silicon oxides, silicon alloys, silicon compounds, tin and tin compounds. The content of the carbon material with respect to the total amount of the negative electrode active material is preferably 50% by mass or more, and more preferably 70% by mass or more. The content of the carbon material may be 100% by mass, but from the viewpoint of obtaining a good effect by using other materials in combination, for example, it is preferably 90% by mass or less, and preferably 80% by mass or less.

The negative electrode active material is preferably doped with lithium ions. In the present specification, the lithium ion doped in the negative electrode active material mainly includes three forms.
The first form is lithium ion, which is preliminarily occluded as a design value in the negative electrode active material before manufacturing the non-aqueous lithium-type power storage element.
The second form is lithium ions stored in the negative electrode active material when a non-aqueous lithium-type power storage element is manufactured and shipped.
The third form is lithium ions occluded in the negative electrode active material after using the non-aqueous lithium-type power storage element as a device.
By doping the negative electrode active material with lithium ions, it is possible to satisfactorily control the capacity and operating voltage of the obtained non-aqueous lithium-type power storage element.

Examples of the carbon material include refractory carbon materials; easily graphitizable carbon materials; carbon black; carbon nanoparticles; activated carbon; artificial graphite; natural graphite; graphitized mesophase carbon spherules; graphite whiskers; polyacenese-based substances. Amorphous carbonaceous materials such as; petroleum-based pitches, coal-based pitches, mesocarbon microbeads, coke, carbonic materials such as synthetic resins (eg, phenolic resins, etc.) Carbonated materials obtained by heat treatment of precursors; full Thermal decomposition products of frill alcohol resin or novolak resin; fullerene; carbon nanophones; and composite carbon materials thereof can be mentioned.

Among these, from the viewpoint of lowering the resistance of the negative electrode, heat treatment is performed in a state where one or more of the carbon materials (hereinafter, also referred to as a base material) and the carbonaceous material precursor coexist, and the base material and the carbon are used. A composite carbon material in which a carbon material derived from the quality material precursor is combined is preferable. The carbonaceous material precursor is not particularly limited as long as it becomes the carbonaceous material by heat treatment, but a petroleum-based pitch or a coal-based pitch is particularly preferable. The substrate and the carbonaceous material precursor may be mixed at a temperature higher than the melting point of the carbonaceous material precursor before the heat treatment. The heat treatment temperature may be any temperature as long as the component generated by volatilization or thermal decomposition of the carbonaceous material precursor to be used becomes the carbonaceous material, but is preferably 400 ° C. or higher and 2500 ° C. or lower, more preferably 500 ° C. It is 2000 ° C. or higher, more preferably 550 ° C. or higher and 1500 ° C. or lower. The atmosphere in which the heat treatment is performed is not particularly limited, but a non-oxidizing atmosphere is preferable.

[Negative electrode active material layer]
In the present embodiment, the negative electrode active material layer contains a first negative electrode active material and a second negative electrode active material made of a carbon material.
Examples of the carbon material include refractory carbon materials; easily graphitizable carbon materials; carbon black; carbon nanoparticles; activated carbon; artificial graphite; natural graphite; graphitized mesophase carbon spherules; graphite whiskers; polyacenese-based substances. Amorphous carbonaceous materials such as; petroleum-based pitches, coal-based pitches, mesocarbon microbeads, coke, carbonaceous materials obtained by heat-treating carbon precursors such as synthetic resins (eg, phenolic resins, etc.); Thermal decomposition products of resins or novolak resins; fullerene; carbon nanophones; and composite carbon materials thereof can be mentioned.
Of the two types of negative electrode active materials, the average particle size of at least one type of negative electrode active material is preferably 1 μm or more and 15 μm or less, and more preferably 1.5 μm or more and 10 μm or less. By containing a negative electrode active material having an average particle size of 1 μm or more, it is possible to increase the electrode strength of the negative electrode and improve the high load charge / discharge characteristics of the power storage element. By containing the negative electrode active material having an average particle size of 15 μm or less, the bulk density of the negative electrode can be increased, so that the energy density of the power storage element can be increased.

In the present embodiment, the negative electrode active material layer includes a first negative electrode active material having a specific surface area of 0.5 m ² / g or more and 35 m ² / g or less calculated by the BET method based on the weight of the negative electrode active material, and BET. It is preferable to include a second negative electrode active material having a specific surface area calculated by the method of 50 m ² / g or more and 1,500 m ² / g or less.
The ratio of the second negative electrode active material is preferably 1.0% by mass to 45.0% by mass based on the total amount of the negative electrode active material contained in the negative electrode active material layer. It is more preferably 2.0% by mass to 35.0% by mass, and further preferably 1.0% by mass to 20.0% by mass. When the ratio of the second negative electrode active material is 1.0% by mass or more, the Li ion diffusion rate in the negative electrode active material layer can be increased, and the power storage element can be increased in output. When the ratio of the second negative electrode active material is 45% by mass or less, the Li-doped amount per unit area can be increased, so that the negative electrode potential can be sufficiently lowered in the lithium doping step described later. This makes it possible to increase the energy density of the power storage element.

It is preferable that the lithium ion doping amount of the first negative electrode active material is 50 mAh / g or more and 520 mAh / g or less per unit mass. More preferably, it is 150 mAh / g or more and 46000 mAh / g or less.
Further, it is preferable that the lithium ion doping amount of the second negative electrode active material is 530 mAh / g or more and 2500 mAh / g or less per unit mass. More preferably, it is 600 mAh / g or more and 2000 mAh / g or less.
If the lithium ion dope amount of the first negative electrode active material and the second negative electrode active material is within the above range, the negative electrode potential is sufficiently lowered in the lithium dope step described later even when two kinds of carbon materials are mixed. be able to. This makes it possible to increase the energy density of the power storage element.

Examples of the first negative electrode active material include natural graphite, artificial graphite, low crystalline graphite, graphitized mesophase carbon globules, graphite whiskers, soft carbon, hard carbon, or a composite carbon material based on any one of them. Can be used.
The graphite-based material used for the negative electrode active material A is not particularly limited, and for example, artificial graphite, natural graphite, graphitized mesophase carbon spherules, graphite whisk, high specific surface area graphite, or the like can be used. .. The average particle size of the graphite material is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 8 μm or less. The above-mentioned graphite-based material may be used as the first negative electrode active material, but it can be more preferably used by performing a composite treatment as described later from the viewpoint of reducing resistance.
The carbonaceous material precursor used in the first negative electrode active material is a solid, liquid, or solvent-soluble organic material that can be combined with a carbonaceous material by heat treatment. The carbonaceous material precursor is not particularly limited as long as it is composited with a graphite-based material by heat treatment, and examples thereof include pitch, mesocarbon microbeads, coke, and synthetic resin (for example, phenol resin). be able to. Among these carbonaceous material precursors, it is preferable to use an inexpensive pitch in terms of manufacturing cost. Pitches are roughly divided into petroleum-based pitches and coal-based pitches. Examples of petroleum-based pitches include distillation residue of crude oil, fluid contact decomposition residue (decant oil, etc.), bottom oil derived from thermal crackers, ethylene tar obtained during naphtha cracking, and the like. The substrate and the carbonaceous material precursor may be mixed at a temperature higher than the melting point of the carbonaceous material precursor before the heat treatment. The heat treatment temperature may be any temperature as long as the component generated by volatilization or thermal decomposition of the carbonaceous material precursor to be used becomes the carbonaceous material, but is preferably 400 ° C. or higher and 2,500 ° C. or lower, more preferably. It is 500 ° C. or higher and 2,000 ° C. or lower, more preferably 550 ° C. or higher and 1,500 ° C. or lower. The atmosphere in which the heat treatment is performed is not particularly limited, but a non-oxidizing atmosphere is preferable.

As the second negative electrode active material, activated carbon, carbon black, template porous carbon, high specific surface area graphite, carbon nanoparticles, or a composite carbon material using any one of them as a base material can be used.
The carbonaceous material precursor used in the second negative electrode active material is an organic material that can be dissolved in a solid, liquid, or solvent, in which the carbonaceous material can be compounded with the amorphous carbon material by heat treatment. Is. The carbonaceous material precursor is not particularly limited as long as it is composited with an amorphous carbon material by heat treatment, but for example, pitch, mesocarbon microbeads, coke, synthetic resin (for example, phenol resin, etc.) and the like. Can be mentioned. Among these carbonaceous material precursors, it is preferable to use an inexpensive pitch in terms of manufacturing cost. Pitches are roughly divided into petroleum-based pitches and coal-based pitches. Examples of petroleum-based pitches include distillation residue of crude oil, fluid contact decomposition residue (decant oil, etc.), bottom oil derived from thermal crackers, ethylene tar obtained during naphtha cracking, and the like. The substrate and the carbonaceous material precursor may be mixed at a temperature higher than the melting point of the carbonaceous material precursor before the heat treatment. The heat treatment temperature may be any temperature as long as the component generated by volatilization or thermal decomposition of the carbonaceous material precursor to be used becomes the carbonaceous material, but is preferably 400 ° C. or higher and 2,500 ° C. or lower, more preferably. It is 500 ° C. or higher and 2,000 ° C. or lower, more preferably 550 ° C. or higher and 1,500 ° C. or lower. The atmosphere in which the heat treatment is performed is not particularly limited, but a non-oxidizing atmosphere is preferable.

In the present embodiment, the negative electrode active material layer preferably has a specific surface area of 4 m ² / g or more and 75 m ² / g or less calculated by the BET method based on the weight of the negative electrode active material. The lower limit of the specific surface area calculated by the BET method is preferably 5 m ² / g or more, more preferably 6 m ² / g or more, and particularly preferably 7 m ² / g or more. The lower limit of the specific surface area calculated by the BET method is 60 m ² / g or less, more preferably 40 m ² / g or less, and particularly preferably 30 m ² / g or less.

In the present embodiment, the negative electrode active material layer appears at the peak intensity ID of the _D band appearing at 1350 ± 15 cm ^-1 and 1585 ± 15 cm -1 in the Raman mapping of the negative electrode active material layer obtained by Raman spectroscopy. The ratio A1 of the mapping area in which the ratio _ID / _IG of the peak intensity IG of the _G band is 0.5 or more and 1.3 or less to the total mapping area is preferably 50% or more and 95% or less. The lower limit of A1 is preferably 60% or more, more preferably 65% or more. The upper limit of A1 is preferably 90% or less and 85% or less.
The negative electrode of the present embodiment has a specific surface area calculated by the BET method in the negative electrode active material layer, and a peak intensity ID of the _D band appearing at 1350 ± 15 cm ^-1 in Raman mapping obtained by Raman spectroscopy on the surface of the negative electrode active material layer. By adjusting the distribution of the _G band peak intensity IG ratio _ID / _IG distribution appearing at 1585 ± 15 cm ^-1 to a specific range, excellent high load charge / discharge cycle characteristics and excellent high voltage High temperature storage characteristics can be obtained. The principle is not clear and is not limited to theory, but it is inferred as follows.
When the specific surface area calculated by the BET method is 4 m ² / g or more and A1 is 60% or more, the high load charge / discharge cycle is improved. The principle is not always clear, but by setting it within the above range, the surface area of the negative electrode active material layer that receives lithium when charging with a large current is large, and the degree of crystallization of the carbon material is low, so lithium is charged and discharged. It is considered that the diffusion of ions is fast and the acceptability of Li is improved, so that lithium precipitation is suppressed when charging with a large current, and the high load charge / discharge cycle characteristics are improved. In particular, when the positive electrode precursor contains a lithium compound, decomposition products of the lithium compound are deposited on the surface of the negative electrode and the acceptability of lithium is lowered, so that lithium is likely to precipitate. Precipitation can be suppressed.
On the other hand, when the specific surface area calculated by the BET method is 75 m ² / g or less and A1 is 95% or less, excellent high-temperature storage characteristics at high voltage are exhibited. Although the principle is not always clear, by setting it within the above range, the decomposition reaction of the electrolytic solution on the surface of the negative electrode can be suppressed, so that excellent high temperature storage characteristics at high voltage can be exhibited. In particular, when the positive electrode precursor contains a lithium compound, the lithium compound decomposes at high voltage, destroys the coating film on the negative electrode surface, and easily generates gas at high temperature. Can exhibit high voltage storage characteristics.
Further, if A1 is 60% or more and 95% or less, it means that the two carbon materials can be uniformly mixed, and since the resistance distribution in the negative electrode active material layer is small, the high load charge / discharge cycle characteristics. Is improved.

In the present embodiment, the negative electrode active material layer may contain optional components such as a conductive filler, a binder, and a dispersion stabilizer, if necessary, in addition to the negative electrode active material capable of occluding and releasing lithium ions.

In the negative electrode of the present embodiment, the ratio A2 of the mapping area in which the _ID / _IG of the negative electrode active material layer is 1.0 or more and 1.3 or less to the total mapping area is preferably 3% or more and 70% or less. .. The lower limit of A2 is more preferably 4% or more, still more preferably 5% or more. The upper limit of A2 is more preferably 50% or less, still more preferably 30% or less. When A2 is 3% or more, the resistance at room temperature is excellent, and when A2 is 70% or less, the energy density is excellent.

In the negative electrode of the present embodiment, the negative electrode active material layer has a pore amount of V _m1 (cc / g) derived from pores having a diameter of 2 nm or more and 50 nm or less calculated by the BJH method based on the weight of the negative electrode active material. When the amount of pores derived from pores having a diameter of 20 nm or more and 50 nm or less is V _m2 (cc / g), it is preferable to satisfy 0.6 ≦ V _m1 / (V _m1 + V _m2 ) ≦ 0.8. The lower limit of V _m1 / (V _m1 + V _m2 ) is more preferably 0.63 or more. The upper limit of V _m1 / (V _m1 + V _m2 ) is more preferably 0.75 or less. When V _m1 / (V _m1 + V _m2 ) is 0.6 or more, the resistance at room temperature is excellent, and when V _m1 / (V _m1 + V _m2 ) is 0.7 or less, the energy density is excellent.

The negative electrode active material layer in the negative electrode of the present embodiment may have at least one peak in a region having a diameter of 20 nm or more and 50 nm or less in the pore distribution curve obtained by analyzing the isotherm at the time of nitrogen desorption by the BJH method. preferable. Having at least one peak in a region having a diameter of 20 nm or more and 50 nm or less is excellent in resistance at low temperatures.
The peel strength of the negative electrode active material layer in the negative electrode of the present embodiment is 0.40 N / cm or more and 2.00 N / cm or less. When the peel strength is 0.40 N / cm or more, it is possible to suppress the loss of the negative electrode active material layer and suppress a slight short circuit. When the peel strength is 2.00 N / cm or less, it means that there is no excessive binder or the like in the negative electrode active material layer, so that the diffusibility of the electrolytic solution can be improved and the resistance can be lowered.
The peel strength of the negative electrode active material layer according to the present invention is a value measured after pressing when the pressing described later is performed. When pressing multiple times, it is a value measured after the final pressing. In the case of a negative electrode that is not pressed, it is a value measured in an unpressed state.
The peel strength of the present invention can be measured by a known method. For example, a peeling test based on JIS Z0237 (2009) "Adhesive Tape / Adhesive Sheet Test Method" may be used. Alternatively, the test method used in the examples described later may be used.

The negative electrode active material may be a material that forms an alloy with lithium (hereinafter, also referred to as “alloy-based negative electrode material”). It is preferable to include at least one selected from the group consisting of silicon, a silicon compound, tin, a tin compound, and a composite material of these and a carbon or a carbonaceous material. As the negative electrode active material, the silicon compound is preferably a silicon oxide, and more preferably SiO _x (0.01 ≦ x ≦ 1 in the formula).

The composite material comprises at least one substrate preferably selected from the group consisting of silicon, silicon compounds, tin, and tin compounds, and non-graphitizable carbon materials; easily graphitizable carbon materials; carbon black; carbon nanos. Particles; Activated carbon; Artificial graphite; Natural graphite; Graphitized mesophase carbon globules; Graphite whiskers; Amorphous carbonaceous materials such as polyacene-based substances; Petroleum-based pitch, coal-based pitch, mesocarbon microbeads, coke, synthetic resin ( At least one selected from the group consisting of a carbonaceous material obtained by heat-treating a carbonaceous material precursor (eg, phenol resin, etc.); a thermal decomposition product of a full frill alcohol resin or a novolak resin; fullerene; carbon nanophones; It is a material obtained by combining the carbon or carbonaceous material of the above by heat treatment or the like.

Among these, a composite material that can be obtained by heat treatment in a state where one or more of the above-mentioned base materials and a petroleum-based pitch or a coal-based pitch coexist is particularly preferable. The substrate and pitch may be mixed at a temperature above the melting point of the pitch prior to the heat treatment. The heat treatment temperature may be any temperature as long as the pitch used is a temperature at which the component generated by volatilization or thermal decomposition becomes a carbonaceous material, but is preferably 400 ° C. or higher and 2500 ° C. or lower, more preferably 500 ° C. or higher and 2000 ° C. or lower, and further. It is preferably 550 ° C or higher and 1500 ° C or lower. The atmosphere in which the heat treatment is performed is not particularly limited, but a non-oxidizing atmosphere is preferable.

The average particle size of the alloy-based negative electrode material is preferably 0.01 μm or more and 30 μm or less. When the average particle size is 0.01 μm or more, the contact area with the non-aqueous electrolyte solution increases, so that the resistance of the lithium ion secondary battery can be reduced. When the average particle size of the negative electrode active material is 30 μm or less, the negative electrode active material layer can be sufficiently thinned, so that the energy density of the lithium ion secondary battery can be improved.

The average particle size of the alloy-based negative electrode material can be adjusted by pulverizing using a wet and dry jet mill built in a classifier, a stirring ball mill, or the like. The crusher is equipped with a centrifugal force classifier, and fine particles crushed in an inert gas environment such as nitrogen and argon can be collected by a cyclone or a dust collector.

The negative electrode active material may contain at least one selected from the group consisting of lithium titanate and titanium oxide capable of occluding and releasing lithium ions. Examples of the lithium titanate include lithium titanate represented by the general formula LixTiyO4 (0.8 ≦ x ≦ 1.4, 1.6 ≦ y ≦ 2.2), and the titanium oxide is a rutile type. Examples thereof include titanium oxide and anatase-type titanium oxide. Among these, it is preferable to include Li4 / 3Ti5 / 3O4 from the viewpoint that the increase in reaction resistance due to the insertion and desorption of Li ions is small and high output can be maintained even in a low temperature environment.

The negative electrode active material layer according to the present invention may contain an optional component such as a conductive filler, a binder, and a dispersion stabilizer, in addition to the negative electrode active material, if necessary.
The type of the conductive filler is not particularly limited, and examples thereof include acetylene black, ketjen black, and vapor phase grown carbon fiber. The amount of the conductive filler used is preferably 0 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the negative electrode active material. It is more preferably 0 parts by mass or more and 20 parts by mass or less, and further preferably 0 parts by mass or more and 15 parts by mass or less.

The binder is not particularly limited, but for example, PVdF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), polyimide, latex, styrene-butadiene copolymer, fluororubber, acrylic copolymer and the like. Can be used. The amount of the binder used is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the negative electrode active material. The amount of the binder used is more preferably 2 parts by mass or more and 27 parts by mass or less, and further preferably 3 parts by mass or more and 25 parts by mass or less. When the amount of the binder is 1 part by mass or more, sufficient electrode strength is developed. On the other hand, when the amount of the binder is 30 parts by mass or less, high input / output characteristics are exhibited without inhibiting the entry and exit of lithium ions into the negative electrode active material.

The dispersion stabilizer is not particularly limited, but for example, PVP (polyvinylpyrrolidone), PVA (polyvinyl alcohol), a cellulose derivative and the like can be used. The amount of the dispersion stabilizer used is preferably 0 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the negative electrode active material. When the amount of the dispersion stabilizer is 10 parts by mass or less, high input / output characteristics are exhibited without inhibiting the entry and exit of lithium ions into the negative electrode active material.

[Negative current collector]
The material constituting the negative electrode current collector in the present invention is preferably a metal foil having high electron conductivity and not deteriorated by elution into a non-aqueous electrolyte solution and reaction with an electrolyte or ions. The metal foil is not particularly limited, and examples thereof include aluminum foil, copper foil, nickel foil, and stainless steel foil. A copper foil is preferable as the negative electrode current collector in the non-aqueous lithium storage element of the present embodiment.
The metal foil may be a normal metal leaf having no irregularities or through holes, a metal leaf having irregularities subjected to embossing, chemical etching, electrolytic precipitation, blasting, etc., expanded metal, punching metal, etc. , A metal foil having through holes such as an etching foil may be used.
In particular, from the viewpoint of ease of electrode production and high electron conductivity, the negative electrode current collector in the present embodiment is preferably non-porous. In the present specification, the “non-porous negative electrode current collector” means that lithium ions pass through the negative electrode current collector and the lithium ions are uniform on the front and back surfaces of the negative electrode, at least in the coated region of the negative electrode active material layer. It means a negative electrode current collector that does not have enough holes to be converted. Therefore, within the range in which the effect of the present invention is exhibited, a negative electrode current collector having an extremely small diameter or a small amount of holes, or a negative electrode current collector having holes in an uncoated region of the negative electrode active material layer is also excluded. is not. Further, in the present embodiment, at least the region where the negative electrode active material layer is coated is non-porous in the negative electrode current collector, and the surplus portion of the negative electrode current collector where the negative electrode active material layer is not coated is covered. May or may not have holes.
The thickness of the negative electrode current collector is not particularly limited as long as the shape and strength of the negative electrode can be sufficiently maintained, but is preferably 1 to 100 μm, for example. When the negative electrode current collector has holes or irregularities, the thickness of the negative electrode current collector shall be measured based on the portion where the holes or irregularities do not exist.

[Manufacturing of negative electrode]
The negative electrode has a negative electrode active material layer on one side or both sides of the negative electrode current collector. In a typical embodiment, the negative electrode active material layer is fixed to the negative electrode current collector.
The negative electrode can be manufactured by a technique for manufacturing electrodes in known lithium ion batteries, electric double layer capacitors and the like. For example, various materials including a negative electrode active material are dispersed or dissolved in water or an organic solvent to prepare a slurry-like coating liquid, and this coating liquid is applied to one or both sides of a negative electrode current collector. A negative electrode can be obtained by forming a coating film and drying it. Further, the obtained negative electrode may be pressed to adjust the film thickness or bulk density of the negative electrode active material layer. Alternatively, it is also possible to dry-mix various materials including the negative electrode active material without using a solvent, press-mold the obtained mixture, and then attach it to the negative electrode current collector using a conductive adhesive. be.

The coating liquid is prepared by dry-blending a part or all of various material powders including the negative electrode active material, and then water or an organic solvent, and / or a liquid or a dispersion in which a binder or a dispersion stabilizer is dissolved or dispersed. A slurry-like substance may be added and adjusted. Further, various material powders containing a negative electrode active material may be added to a liquid or slurry-like substance in which a binder or a dispersion stabilizer is dissolved or dispersed in water or an organic solvent. Although the adjustment of the coating liquid is not particularly limited, a homodisper or a multi-axis disperser, a planetary mixer, a disperser such as a thin film swirl type high-speed mixer and the like can be preferably used. In order to obtain a coating liquid in a good dispersed state, it is preferable to disperse at a peripheral speed of 1 m / s or more and 50 m / s or less. A peripheral speed of 1 m / s or more is preferable because various materials are satisfactorily dissolved or dispersed. Further, when the peripheral speed is 50 m / s or less, various materials are not destroyed by heat or shearing force due to dispersion, and reaggregation does not occur, which is preferable.

The viscosity (ηb) of the coating liquid is preferably 1,000 mPa · s or more and 20,000 mPa · s or less. The viscosity (ηb) is more preferably 1,500 mPa · s or more and 10,000 mPa · s or less, and further preferably 1,700 mPa · s or more and 5,000 mPa · s or less. When the viscosity (ηb) is 1,000 mPa · s or more, liquid dripping during formation of the coating film is suppressed, and the width and film thickness of the coating film can be satisfactorily controlled. Further, when it is 20,000 mPa · s or less, the pressure loss in the flow path of the coating liquid when using the coating machine is small and stable coating can be performed, and the coating film thickness can be controlled to be less than the desired coating film thickness.
The TI value (thixotropy index value) of the coating liquid is preferably 1.1 or more. It is more preferably 1.2 or more, still more preferably 1.5 or more. When the TI value is 1.1 or more, the coating film width and the film thickness can be satisfactorily controlled.

The formation of the coating film is not particularly limited, but a coating machine such as a die coater, a comma coater, a knife coater, or a gravure coating machine can be preferably used. The coating film may be formed by a single-layer coating or a multi-layer coating. Further, the coating speed is preferably 0.1 m / min or more and 100 m / min or less. The coating speed is more preferably 0.5 m / min or more and 70 m / min or less, and further preferably 1 m / min or more and 50 m / min or less. If the coating speed is 0.1 m / min or more, stable coating can be performed. On the other hand, if it is 100 m / min or less, sufficient coating accuracy can be ensured.

[Primary drying]
The coating film of the negative electrode is preferably dried by a drying method such as hot air drying or infrared (IR) drying, and more preferably far infrared rays, near infrared rays, or hot air at 50 ° C. or higher. The coating film may be dried at a single temperature, or may be dried at different temperatures in multiple stages. Moreover, you may dry by combining a plurality of drying methods. The drying temperature is preferably 25 ° C. or higher and 200 ° C. or lower, more preferably 40 ° C. or higher and 180 ° C. or lower, and further preferably 50 ° C. or higher and 140 ° C. or lower. When the drying temperature is 25 ° C. or higher, the solvent in the coating film can be sufficiently volatilized. On the other hand, when the drying temperature is 200 ° C. or lower, it is possible to suppress cracking of the coating film due to rapid volatilization of the solvent, uneven distribution of the binder due to migration, and oxidation of the negative electrode current collector or the negative electrode active material layer.
The water content in the negative electrode after the primary drying is preferably 1% or more and 10% or less, with the mass of the negative electrode active material layer as 100%. When the water content is 1% or more, cracking of the negative electrode due to excessive drying can be suppressed and the resistance can be lowered. When the water content is 10% or less, the deactivation of alkali metal ions in the non-aqueous lithium storage element can be suppressed and the energy density can be increased.
The water content contained in the negative electrode can be measured by, for example, the Karl Fischer titration method (JIS 0068 (2001) “Method for measuring water content of chemical products”).

[press]
A press machine such as a hydraulic press machine or a vacuum press machine can be preferably used for pressing the negative electrode. The film thickness, bulk density and electrode strength of the negative electrode active material layer can be adjusted by the press pressure described later, the gap between the press rolls, and the surface temperature of the press portion. The press pressure is preferably 0.5 kN / cm or more and 20 kN / cm or less, more preferably 1 kN / cm or more and 10 kN / cm or less, and further preferably 2 kN / cm or more and 7 kN / cm or less. When the press pressure is 0.5 kN / cm or more, the electrode strength can be sufficiently increased. On the other hand, when the press pressure is 20 kN / cm or less, the negative electrode does not bend or wrinkle, and the film thickness or bulk density of the negative electrode active material can be adjusted to a desired value. Further, the gap between the press rolls can be set to an arbitrary value according to the film thickness of the negative electrode after drying so as to have a desired film thickness or bulk density of the negative electrode active material layer. Further, the pressing speed can be set to any speed at which the negative electrode does not bend or wrinkle. Further, the surface temperature of the pressed portion may be room temperature or may be heated if necessary.
The lower limit of the surface temperature of the pressed portion in the case of heating is preferably the melting point of the binder of -60 ° C or higher, more preferably the melting point of the binder of -40 ° C or higher, and further preferably the melting point of the binder of -30 ° C or higher. Is. On the other hand, the upper limit of the surface temperature of the pressed portion when heating is preferably preferably the melting point of the binder to be used plus 50 ° C. or lower, more preferably the melting point of the binder plus 30 ° C. or lower, and further preferably the melting point of the binder plus. It is 20 ° C. or lower. For example, when PVdF (polyvinylidene fluoride: melting point 150 ° C.) is used as the binder, it is preferable to heat it to 90 ° C. or higher and 200 ° C. or lower, more preferably 105 ° C. or higher and 180 ° C. or lower, and further preferably 120 ° C. or higher. It is to heat to 170 ° C. or lower. The melting point of the binder can be determined from the endothermic peak position of DSC (Differential Scanning Calorimetry). For example, using a differential scanning calorimeter "DSC7" manufactured by PerkinElmer, 10 mg of sample resin is set in a measurement cell, and the temperature rises from 30 ° C. to 250 ° C. at a heating rate of 10 ° C./min in a nitrogen gas atmosphere. When the temperature is raised, the heat absorption peak temperature in the temperature raising process becomes the melting point.
Further, the press may be performed a plurality of times while changing the conditions of the press pressure, the gap, the speed, and the surface temperature of the press portion.

[Secondary drying]
The coating film of the negative electrode is preferably dried by using a drying method such as vacuum drying, hot air drying, and infrared (IR) drying. The coating film may be dried at a single temperature, or may be dried at different temperatures in multiple stages. Moreover, you may dry by combining a plurality of drying methods. The drying temperature is preferably 160 ° C. or higher and 250 ° C. or lower, and more preferably 180 ° C. or higher and 240 ° C. or lower. The purpose of the secondary drying is to dry the dispersion medium that has not completely volatilized in the primary drying or the moisture in the air that has absorbed moisture. The dispersion medium contained in the negative electrode after drying is preferably 0.01% or more and 3% or less with the mass of the negative electrode active material layer as 100%. When the dispersion medium is 0.01% or more, deterioration of the binder due to excessive drying can be suppressed and the resistance can be lowered. When the dispersion medium is 3% or less, the deactivation of alkali metal ions in the non-aqueous lithium storage element can be suppressed and the capacity can be increased. After the secondary drying, it is preferable to store in an environment with a dew point of −30 ° C. or lower.

[Process sequence of drying and pressing]
The above-mentioned production of the negative electrode is preferably carried out in the order of [primary drying] → [press] → [secondary drying], and after the primary drying, the binder sufficiently contains the dispersion medium. It has high flexibility, suppresses structural destruction of the binder by pressing, and ensures conductivity between active materials. Therefore, the amount of the sulfur compound formed in the negative electrode active material layer is made uniform, and high output is possible.
More preferably, it is carried out in the order of [primary drying] → [secondary drying] → [pressing], and by finishing the pressing, the increase in the film thickness of the negative electrode due to the secondary drying is suppressed, and charging / discharging is performed. The swelling and contraction of time is alleviated. Therefore, the high temperature durability can be improved by increasing the stability of the sulfur compound formed in the negative electrode active material layer. Again, by optimizing the press conditions, structural destruction of the binder is suppressed and the output is increased.
Further, [primary drying] and [secondary drying] can be integrated as long as the peel strength of the negative electrode is not lowered and cracks do not occur.

The melting point of the binder can be determined from the endothermic peak position of DSC (Differential Scanning Calorimetry). For example, using a differential scanning calorimeter "DSC7" manufactured by PerkinElmer, 10 mg of sample resin is set in a measurement cell, and the temperature rises from 30 ° C. to 250 ° C. at a heating rate of 10 ° C./min in a nitrogen gas atmosphere. The temperature rises, and the heat absorption peak temperature in the temperature rise process becomes the melting point.
Further, the press may be performed a plurality of times while changing the conditions of the press pressure, the gap, the speed, and the surface temperature of the press portion.

[Measurement item]
The BET specific surface area, the average pore diameter, the mesopore amount, and the micropore amount in the present invention are values obtained by the following methods, respectively. The sample is vacuum-dried at 200 ° C. for a whole day and night, and the isotherms of adsorption and desorption are measured using nitrogen as an adsorbent. Using the isotherms on the adsorption side obtained here, the BET specific surface area is the BET multi-point method or the BET one-point method, and the average pore diameter is the mesopores by dividing the total pore volume per mass by the BET specific surface area. The amount is calculated by the BJH method, and the amount of micropores is calculated by the MP method.
The BJH method is a calculation method generally used for analysis of mesopores, and has been proposed by Barrett, Joiner, Hallenda et al. (Non-Patent Document 1).
The MP method means a method for obtaining the micropore volume, the micropore area, and the distribution of micropores by using the "t-plot method" (Non-Patent Document 2). S. This is a method devised by Mikhair, Brunauer, and Bodor (Non-Patent Document 3).

The average particle size in the present invention is the particle size at the point where the cumulative curve is 50% when the cumulative curve is obtained with the total product as 100% when the particle size distribution is measured using the particle size distribution measuring device (that is,). Refers to 50% diameter (Median diameter). This average particle size can be measured using a commercially available laser diffraction type particle size distribution measuring device.

The amount of lithium ion doped in the negative electrode active material in the non-aqueous lithium-type power storage element at the time of shipment and after use can be known, for example, as follows.
First, the negative electrode active material layer in the present embodiment is washed with ethyl methyl carbonate or dimethyl carbonate and air-dried, and then an extract extracted with a mixed solvent consisting of methanol and isopropanol and a negative electrode active material layer after extraction are obtained. This extraction is typically performed in an Ar box at an ambient temperature of 23 ° C.
The amount of lithium contained in the extract obtained as described above and the negative electrode active material layer after extraction is quantified using, for example, ICP-MS (inductively coupled plasma mass spectrometer), and the amount thereof is quantified. By obtaining the total, the amount of lithium ions doped in the negative electrode active material can be known. Then, the obtained value may be allocated by the amount of the negative electrode active material used for extraction to calculate the numerical value in the above unit.

For the primary particle size in the present invention, the powder is photographed in several fields with an electron microscope, and the particle size of the particles in those fields is measured by about 2,000 to 3,000 using a fully automatic image processing device or the like. However, it can be obtained by a method in which the value obtained by arithmetically averaging these is used as the primary particle size.

In the present specification, the dispersity is a value obtained by a dispersity evaluation test using a grain gauge specified in JIS K5600. That is, a sufficient amount of sample is poured into the tip of the deeper groove of the grain gauge having a groove of a desired depth according to the size of the grain, and the sample is slightly overflowed from the groove. Next, the long side of the scraper is parallel to the width direction of the gauge, and the cutting edge is placed so as to contact the deep tip of the groove of the grain gauge, and the scraper is held so as to be the surface of the gauge while the long side direction of the groove. Pull the surface of the gauge at a right angle to the depth of the groove at a uniform speed for 1 to 2 seconds, and shine light at an angle of 20 ° or more and 30 ° or less within 3 seconds after the pulling is completed. Observe and read the depth at which the grain appears in the groove of the grain gauge.

The viscosity (ηb) and the TI value in the present invention are values obtained by the following methods, respectively. First, a stable viscosity (ηa) is obtained after measuring for 2 minutes or more under the conditions of a temperature of 25 ° C. and a shear rate of 2s-1 using an E-type viscometer. Next, the viscosity (ηb) measured under the same conditions as above is obtained except that the shear rate is changed to 20s-1. Using the viscosity value obtained above, the TI value is calculated by the formula of TI value = ηa / ηb. When increasing the shear rate from 2s-1 to 20s-1, it may be increased in one step, or the shear rate may be increased in multiple steps within the above range, and the viscosity may be increased while appropriately acquiring the viscosity at the shear rate. You may let me.

The texture of the negative electrode active material layer is preferably 10 g · m ^{-2 or more and 100 g · m -2 or} less per one side of the negative electrode current collector, and more preferably 12 g · m ^-2 or more and 80 g · m ^-2 per one side. It is less than or equal to, and more preferably 15 g · m ^-2 or more and 50 g · m ^-2 or less. If the basis weight is 10 g · m ^-2 or more, the high load charge / discharge characteristics can be improved. On the other hand, if the basis weight is 100 g · m ^-2 or less, the ion diffusion resistance in the electrode can be kept low. Therefore, sufficient output characteristics can be obtained, the cell volume can be reduced, and the energy density can be increased. The upper and lower limits of the basis weight range of the negative electrode active material layer can be arbitrarily combined.

The film thickness of the negative electrode active material layer is preferably 10 μm or more and 150 μm or less per one side. The lower limit of the film thickness of the negative electrode active material layer is more preferably 12 μm or more, still more preferably 15 μm or more. The upper limit of the film thickness of the negative electrode active material layer is more preferably 120 μm or less, still more preferably 80 μm or less. When this film thickness is 10 μm or more, no streaks or the like are generated when the negative electrode active material layer is applied, and the coatability is excellent. On the other hand, when this film thickness is 150 μm or less, high energy density can be developed by reducing the cell volume. The film thickness of the negative electrode active material layer when the current collector has through holes or irregularities means the average value of the film thickness per surface of the portion of the current collector that does not have through holes or irregularities.

The bulk density of the negative electrode active material layer is preferably 0.30 g / cm ³ or more and 1.8 g / cm ³ or less, more preferably 0.40 g / cm ³ or more and 1.5 g / cm ³ or less, and further preferably 0. .45 g / cm ³ or more and 1.3 g / cm ³ or less. When the bulk density is 0.30 g / cm ³ or more, sufficient strength can be maintained and sufficient conductivity between the negative electrode active materials can be exhibited. Further, when the bulk density is 1.8 g / cm ³ or less, it is possible to secure pores in which ions can be sufficiently diffused in the negative electrode active material layer.

｛式中、Ｘ^１は、水素、リチウム、炭素数１～６のアルキル基、炭素数１～６のモノ若しくはポリヒドロキシアルキル基又はそのリチウムアルコキシド、炭素数２～６のアルケニル基、炭素数２～６のモノ若しくはポリヒドロキシアルケニル基又はそのリチウムアルコキシド、炭素数３～６のシクロアルキル基、又はアリール基であり、そしてＸ^２は、水素、リチウム、又は炭素数１～１２のアルキル基である。｝
で表される硫黄化合物の総量が、正極活物質の単位質量当たり０．１０×１０^－５ｍｏｌ／ｇ～５０×１０^－５ｍｏｌ／ｇである。 [Compounds in the positive electrode active material layer]
The positive electrode active material layer according to the present invention has the following formula (1):

{In the formula, X ¹ is hydrogen, lithium, an alkyl group having 1 to 6 carbon atoms, a mono or polyhydroxyalkyl group having 1 to 6 carbon atoms or a lithium alkoxide thereof, an alkenyl group having 2 to 6 carbon atoms, and 2 carbon atoms. A mono or polyhydroxyalkenyl group of ~ 6 or a lithium alkoxide thereof, a cycloalkyl group or an aryl group having 3 to 6 carbon atoms, and X ² is a hydrogen, lithium, or an alkyl group having 1 to 12 carbon atoms. .. }
The total amount of the sulfur compound represented by is 0.10 × 10 ^-5 mol / g to 50 × 10 ^-5 mol / g per unit mass of the positive electrode active material.

In equation (1), from the viewpoint of electrochemical stability
X ¹ is hydrogen, lithium, an alkyl group having 1 to 4 carbon atoms, a mono or polyhydroxyalkyl group having 1 to 4 carbon atoms or a lithium alkoxide thereof, and X ² is hydrogen, lithium, or an alkyl group having 1 to 4 carbon atoms. A compound which is an alkyl group of 3 is preferable.

More preferably, among the sulfur compounds represented by the formula (1),
X ¹ is an alkyl group having 1 to 3 carbon atoms, a mono or polyhydroxyalkyl group having 1 to 3 carbon atoms or a lithium alkoxide thereof, and X ² is a hydrogen, lithium or an alkyl group having 1 to 3 carbon atoms. The compound is preferable.

The sulfonic acid derivative particularly preferable as the sulfur compound represented by the formula (1) is as follows:
LiOCH ₂ CH ₂ OSO ₃ X ¹¹ {In the formula, X ¹¹ is hydrogen, lithium, or an alkyl group having 1 to 2 carbon atoms. }, CH ₃ CH ₂ OSO ₃ X ¹¹ {In the formula, X ¹¹ is hydrogen, lithium, or an alkyl group having 1 to 2 carbon atoms. }, And CH ₃ OSO ₃ X ¹¹ {In the formula, X ¹¹ is hydrogen, lithium, or an alkyl group having 1 to 2 carbon atoms. } Is a compound represented by.

The total amount of the sulfur compound shown above is preferably 0.30 × ^10-5 mol / g or more, preferably 0.50 × ^10-5 mol / g or more, per unit mass of the positive electrode active material layer. It is more preferably present, and more preferably 1.5 × 10 ^-5 mol / g or more. When the total amount of the sulfur compound is 0.10 × ^10-5 mol / g or more per unit mass of the positive electrode active material layer, the non-aqueous electrolyte solution does not come into contact with the positive electrode active material. Therefore, the capacity of the positive electrode can be maintained for a long period of time without deactivating the active points at the active material interface due to the deposits formed by the oxidative decomposition of the non-aqueous electrolyte solution.

The total amount of the sulfur compound is preferably 45 × 10 ^-5 mol / g or less, more preferably 40 × 10 ^-5 mol / g or less, per unit mass of the positive electrode active material layer. It is more preferably 35 × 10 ^-5 mol / g or less. When the total amount of the sulfur compound is 50 × ^10-5 mol / g or less per unit mass of the positive electrode active material layer, the diffusion of Li ions at the interface of the positive electrode active material is not hindered and high input / output characteristics are exhibited. Can be done.

[Compounds in the negative electrode active material layer]
In the negative electrode active material layer according to the present invention, the total amount of the sulfur compound represented by the above formula (1) is 0.10 × 10 ^-5 mol / g to 40 × 10 ^-5 mol per unit mass of the negative electrode active material layer. / G.

The total amount of sulfur compounds in the negative electrode active material layer is preferably 0.30 × ^10-5 mol / g or more, preferably 0.50 × ^10-5 mol / g or more, per unit mass of the negative electrode active material layer. It is more preferably present, and more preferably 1.5 × 10 ^-5 mol / g or more. When the total amount of the sulfur compound is 0.10 × ^10-5 mol / g or more per unit mass of the negative electrode active material layer, the non-aqueous electrolyte solution does not come into contact with the negative electrode active material. Therefore, it is possible to prevent the Li doped in the negative electrode from being inactivated by the reduction decomposition of the non-aqueous electrolyte solution, and to maintain the capacity of the negative electrode for a long period of time.

The total amount of the sulfur compound shown above is preferably 35 × ^10-5 mol / g or less, and preferably 30 × ^10-5 mol / g or less, per unit mass of the negative electrode active material layer. More preferably, it is 20 × 10 ^-5 mol / g or less. When the total amount of the sulfur compound is 40 × ^10-5 mol / g or less per unit mass of the negative electrode active material layer, the diffusion of Li ions at the negative electrode active material interface is not hindered and high input / output characteristics are exhibited. Can be done.

｛式中、Ｒ^５～Ｒ^８は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表される環状硫酸化合物、例えば、エチレンスルファート、１，２－プロピレンスルファート、トリメチレンスルファートなどが挙げられ、これらの中から選択される少なくとも１種以上を、非水系電解液の総量を基準として、０．１質量％～５質量％を非水系電解液に含有させることが更に好ましい。 As a method for expressing the sulfur compound shown above in the negative electrode active material layer and the positive electrode active material layer, for example,
A method of mixing a sulfur-containing compound in a negative electrode active material layer and a positive electrode active material layer,
A method of adsorbing a sulfur-containing compound on a negative electrode active material layer and a positive electrode active material layer,
Examples thereof include a method of electrochemically precipitating a sulfur-containing compound on the negative electrode active material layer and the positive electrode active material layer.
Above all, the negative electrode active material layer and the positive electrode active material are contained in the non-aqueous electrolytic solution by containing a precursor capable of decomposing to produce the sulfur compound, and utilizing the decomposition reaction in the step of producing the power storage element. A method of depositing the compound in the layer is preferable, and a method of depositing the compound through a step of oxidatively decomposing the alkali metal compound in the positive electrode precursor described later at a high potential is not clear in principle, but is in a low temperature environment. It is more preferable because a film that can maintain high input / output characteristics is formed even underneath.
As a precursor capable of producing the compound, the following formula (1-1):

{In the formula, R ⁵ to R ⁸ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Examples of the cyclic sulfuric acid compound represented by, for example, ethylene sulphate, 1,2-propylene sulphate, trimethylene sulphate, etc., may be mentioned, and at least one selected from these may be used as the total amount of the non-aqueous electrolyte solution. It is more preferable to contain 0.1% by mass to 5% by mass in the non-aqueous electrolytic solution.

The ratio A / B of the sulfur compound according to the present invention to the content A per unit mass of the positive electrode active material layer and the content B per unit mass of the negative electrode active material layer is 0.50 or more and 12 or less. .. The A / B is more preferably 0.7 or more and 8.5 or less, and further preferably 0.9 or more and 6.0 or less. When the A / B is 0.50 or more, the non-aqueous electrolyte solution is not oxidatively decomposed at the positive electrode interface to deteriorate the positive electrode active material, and the diffusion of Li ions is not hindered at the negative electrode interface. .. Further, when the A / B is 12 or less, the non-aqueous electrolyte solution is not reduced and decomposed at the negative electrode interface to deteriorate the negative electrode active material, and the diffusion of Li ions is not hindered at the positive electrode interface. .. Therefore, when the A / B is 0.50 or more and 12 or less, it is possible to achieve both sufficient high temperature durability and high input / output characteristics in a wide range of temperatures. Since A / B represents the ratio, the units of the contents A and B may be arbitrary, and may be, for example, mol / g, respectively.

[Electrolytic solution]
The electrolytic solution of this embodiment is a non-aqueous electrolytic solution. That is, this electrolytic solution contains a non-aqueous solvent described later. The non-aqueous electrolyte solution preferably contains 0.5 mol / L or more of a lithium salt based on the total amount of the non-aqueous electrolyte solution. That is, the non-aqueous electrolyte solution preferably contains lithium ions as an electrolyte.

[Lithium salt]
The non-aqueous electrolyte solution of the present embodiment has, as lithium salts, for example, (LiN (SO ₂ F) ₂ ), LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiN (SO ₂ ). CF ₃ ) (SO ₂ C ₂ F ₅ ), LiN (SO ₂ CF ₃ ) (SO ₂ C ₂ F ₄ H), LiC (SO ₂ F) ₃ , LiC (SO ₂ CF ₃ ) ₃ , LiC (SO ₂ ) C ₂ F ₅ ) ₃ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiPF ₆ , LiBF ₄ , etc. can be used alone, or two or more of them may be mixed and used. The non-aqueous electrolyte solution preferably contains at least one selected from the group consisting of LiPF ₆ , LiN (SO ₂ F) ₂ and LiBF ₄ because of its ability to exhibit high conductivity, and LiPF ₆ and / or LiBF ₄ And LiN (SO ₂ F) ₂ are more preferable.
The lithium salt concentration in the non-aqueous electrolyte solution is preferably 0.5 mol / L or more, more preferably 0.5 mol / L or more and 2.0 mol / L or less, based on the total amount of the non-aqueous electrolyte solution. .. When the lithium salt concentration is 0.5 mol / L or more, anions are sufficiently present, so that the capacity of the power storage element can be sufficiently increased. Further, when the lithium salt concentration is 2.0 mol / L or less, it is possible to prevent undissolved lithium salt from precipitating in the non-aqueous electrolytic solution and the viscosity of the electrolytic solution from becoming too high, and the conductivity is lowered. It is preferable because it does not deteriorate the output characteristics.

The non-aqueous electrolyte solution of the present embodiment preferably contains LiN (SO ₂ F) ₂ having a concentration of 0.1 mol / L or more and 1.5 mol / L or less based on the total amount of the non-aqueous electrolyte solution. The concentration of SO ₂ F) ₂ is more preferably 0.3 mol / L or more and 1.2 mol / L or less. When the LiN (SO ₂ F) ₂ concentration is 0.1 mol / L or more, the ionic conductivity of the electrolytic solution is increased, and an appropriate amount of the electrolyte film is deposited on the negative electrode interface, whereby the gas due to the decomposition of the electrolytic solution is released. Can be reduced. On the other hand, when this concentration is 1.5 mol / L or less, precipitation of the electrolyte salt does not occur during charging and discharging, and the viscosity of the electrolytic solution does not increase even after a long period of time.

[Non-aqueous solvent]
The non-aqueous electrolyte solution of the present embodiment contains a cyclic carbonate as a non-aqueous solvent. The inclusion of the cyclic carbonate in the non-aqueous electrolyte solution is advantageous in that it dissolves a lithium salt having a desired concentration and that an appropriate amount of the lithium compound is deposited in the positive electrode active material layer. Examples of the cyclic carbonate include ethylene carbonate (EC), propylene carbonate, butylene carbonate, vinylene carbonate, fluoroethylene carbonate and the like.
The total content of the cyclic carbonate is preferably 15% by mass or more, more preferably 20% by mass or more, based on the total amount of the non-aqueous electrolyte solution. When the total content is 15% by mass or more, it is possible to dissolve a lithium salt having a desired concentration, and high lithium ion conductivity can be exhibited. Further, an appropriate amount of the lithium compound can be deposited on the positive electrode active material layer, and oxidative decomposition of the electrolytic solution can be suppressed.

The non-aqueous electrolyte solution of the present embodiment preferably contains dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC), which are chain carbonate compounds, as the non-aqueous solvent. The volume ratio (DMC / EMC) of the ethylmethyl carbonate to the dimethyl carbonate is preferably 0.5 or more and 8.0 or less, more preferably 0.8 or more and 6.0 or less, and 1.0 or more. It is more preferably 4.0 or less. When the DMC / EMC is 0.5 or more, the viscosity of the electrolytic solution can be reduced and high lithium ion conductivity can be exhibited. When DMC / EMC is 8.0 or less, the melting point of the mixed solvent can be kept low, and high input / output characteristics can be exhibited even in a low temperature environment.

Further, the non-aqueous electrolyte solution of the present embodiment may contain other chain carbonate as the non-aqueous solvent. Examples of other chain carbonates include dialkyl carbonate compounds typified by diethyl carbonate, dipropyl carbonate, dibutyl carbonate and the like. Dialkyl carbonate compounds are typically unsubstituted.
The total content of the chain carbonate is preferably 30% by mass or more, more preferably 35% by mass or more, preferably 95% by mass or less, and more preferably 90% by mass or less, based on the total amount of the non-aqueous electrolyte solution. be. When the content of the chain carbonate is 30% by mass or more, the viscosity of the electrolytic solution can be reduced and high lithium ion conductivity can be exhibited. When the total concentration is 95% by mass or less, the electrolytic solution can further contain the additives described later.

｛式中、Ｒ^１～Ｒ^４は、それぞれ独立に、水素原子、ハロゲン原子、ホルミル基、アセチル基、ニトリル基、アセチル基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、及び炭素数１～６のアルキルエステルから成る群から選択される少なくとも１つを表す。｝
で表されるチオフェン化合物；
下記式（１－３）：

｛式中、Ｒ^９～Ｒ^１４は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表されるスルトン化合物；
下記式（１－４）：

｛式中、Ｒ^１５～Ｒ^２０は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表されるスルトン化合物；
下記式（１－５）：

｛式中、Ｒ^２１～Ｒ^２６は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよい。｝
で表される化合物；並びに
下記式（１－６）：

｛式中、Ｒ^２７～Ｒ^３０は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、及び炭素数１～１２のハロゲン化アルキル基から成る群より選ばれる少なくとも１つを表し、互いに同一であっても異なっていてもよく；そしてｎは０～３の整数である。｝
で表される環状亜硫酸化合物から成る群から選択される少なくとも１つの含硫黄化合物、下記式（２）：

｛式中、Ｘ^１～Ｘ^３は、それぞれ独立に、水素原子、ハロゲン原子、ホルミル基、アセチル基、ニトリル基、アセチル基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数１～６のアルキルエステル、又は－Ｓｉ（Ｒ^１）_３（式中、Ｒ^１は炭素数１～６のアルキル基を表す。）を表し、かつＸ^１～Ｘ^３の少なくとも１つは、水素原子ではない。｝
で表されるリン酸エステル化合物、又は下記式（３）：
Ｒ^３１－Ｏ－Ｒ^３２ （３）
｛式中、Ｒ^３１は、ハロゲン原子又は炭素数１～１２のハロゲン化アルキル基であり、かつＲ^３２は、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、又は炭素数１～１２のハロゲン化アルキル基である。｝
で表される非環状含ハロゲンエーテルが好ましい。 [Additive]
The non-aqueous electrolytic solution of the present embodiment may further contain an additive. The additive is not particularly limited, and is, for example, a sulfur-containing compound, a phosphoric acid ester compound, an acyclic halogen-containing ether, a cyclic phosphazene, a fluorocyclic carbonate, a cyclic carbonate ester, a cyclic carboxylic acid ester, a cyclic acid anhydride and the like. Can be used alone, or two or more of them may be mixed and used.
Among these, the following formula (1-2):

{In the formula, R ¹ to R ⁴ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , And at least one selected from the group consisting of alkyl esters having 1 to 6 carbon atoms. }
Thiophene compound represented by;
The following formula (1-3):

{In the formula, R ⁹ to R ¹⁴ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Sultone compound represented by;
The following formula (1-4):

{In the formula, R ¹⁵ to R ²⁰ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Sultone compound represented by;
The following formula (1-5):

{In the formula, R ²¹ to R ²⁶ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different. }
The compound represented by; and the following formula (1-6):

{In the formula, R ²⁷ to R ³⁰ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
At least one sulfur-containing compound selected from the group consisting of cyclic sulfurous acid compounds represented by the following formula (2):

{In the formula, X ¹ to X ³ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , An alkyl ester having 1 to 6 carbon atoms, or -Si (R ¹ ) ₃ (in the formula, R ¹ represents an alkyl group having 1 to 6 carbon atoms), and at least one of X ¹ to X ³ . Is not a hydrogen atom. }
Phosphoric acid ester compound represented by, or the following formula (3):
R ³¹ -OR ³² (3)
{In the formula, R ³¹ is a halogen atom or a halogenated alkyl group having 1 to 12 carbon atoms, and R ³² is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, or 1 to 12 carbon atoms. Halogen alkyl group. }
The acyclic halogen-containing ether represented by is preferable.

It is preferable that the electrolytic solution contains a sulfur-containing compound selected from the compounds represented by the general formulas (1-2) to (1-6). More preferably, the thiophene compound represented by the formula (1-2) is thiophene, 2-methylthiophene, 3-methylthiophene, 2-cyanothiophene, 3-cyanothiophene, 2,5-dimethylthiophene, 2-methoxy. Thiophene, 3-methoxythiophene, 2-chlorothiophene, 3-chlorothiophene, 2-acetylthiophene, or 3-acetylthiophene, and the sultone compound represented by the formula (1-3) is 1,3-propane. Sultone, 2,4-butane sultone, 1,4-butane sultone, 1,3-butane sultone or 2,4-pentane sultone, and the sultone compound represented by the formula (1-4) is 1,3-propen sultone or 1,4-Butensultone, the compound represented by the formula (1-5) is 3-sulfolene, and / or the cyclic sulfite compound represented by the formula (1-6) is ethylene sulfite, 1, It is propylene 2-sultone or propylene 1,3-sultone, and more preferably, one or more of the compounds selected from these are contained in the electrolytic solution.

The total content of the sulfur-containing compound in the non-aqueous electrolyte solution of the non-aqueous lithium-type power storage element in the present embodiment is 0.1% by mass or more and 5% by mass or less based on the total amount of the non-aqueous electrolyte solution. preferable. When the total content of the sultone compound in the non-aqueous electrolytic solution is 0.1% by mass or more, it is possible to suppress the decomposition of the electrolytic solution at a high temperature and suppress the gas generation. On the other hand, when the total content is 5% by mass or less, the decrease in the ionic conductivity of the electrolytic solution can be suppressed, and high input / output characteristics can be maintained. Further, the content of the sulton compound present in the non-aqueous electrolyte solution of the non-aqueous lithium-type power storage element is preferably 0.3% by mass or more and 4% by mass or less from the viewpoint of achieving both high input / output characteristics and durability. , More preferably 0.5% by mass or more and 3% by mass or less.

｛式中、Ｘ^１～Ｘ^３は、それぞれ独立に、水素原子、ハロゲン原子、ホルミル基、アセチル基、ニトリル基、アセチル基、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数１～６のアルキルエステル、又は－Ｓｉ（Ｒ^１）_３（式中、Ｒ^１は炭素数１～６のアルキル基を表す。）を表し、かつＸ^１～Ｘ^３の少なくとも１つは、水素原子ではない。｝
で表されるリン酸エステル化合物を非水系電解液に含有させることが好ましい。
前記式（２）で表されるリン酸エステル化合物としては、例えば、トリメチルホスフェート、トリエチルホスフェート、トリブチルホスフェート、リン酸トリス（トリメチルシリル）、トリトリルホスフェート、トリフェニルホスフェート、ジオクチルホスフェート、トリオクチルホスフェート、リン酸トリス（４－ニトロフェニル）等を挙げることができ、これらのうちから選択される１種以上が好ましい。 [Phosphate ester compound]
The following formula (2):

{In the formula, X ¹ to X ³ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , An alkyl ester having 1 to 6 carbon atoms, or -Si (R ¹ ) ₃ (in the formula, R ¹ represents an alkyl group having 1 to 6 carbon atoms), and at least one of X ¹ to X ³ . Is not a hydrogen atom. }
It is preferable to include the phosphoric acid ester compound represented by (1) in the non-aqueous electrolyte solution.
Examples of the phosphoric acid ester compound represented by the formula (2) include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris phosphate (trimethylsilyl), tritryl phosphate, triphenyl phosphate, dioctyl phosphate, trioctyl phosphate and phosphorus. Tris (4-nitrophenyl) acid and the like can be mentioned, and one or more selected from these is preferable.

The content of the phosphoric acid ester compound is preferably 0.1% by mass or more and 3% by mass or less, more preferably 0.3% by mass or more and 2.5% by mass or less, based on the total amount of the non-aqueous electrolyte solution. .. When the content of the phosphoric acid ester compound is 0.1% by mass or more, the stability of the non-aqueous electrolyte solution against oxidative decomposition is enhanced, and the capacity deterioration at high temperature can be suppressed. On the other hand, when the content of the phosphoric acid ester compound is 3% by mass or less, the reaction resistance at the interface between the positive electrode and the electrolytic solution can be kept low, so that high input / output characteristics can be exhibited. The phosphoric acid ester compound may be used alone or in combination of two or more.

[Acyclic halogen-containing ether]
The following formula (3):
R ³¹ -OR ³² (3)
{In the formula, R ³¹ is a halogen atom or a halogenated alkyl group having 1 to 12 carbon atoms, and R ³² is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, or 1 to 12 carbon atoms. Halogen alkyl group. }
It is preferable that the electrolytic solution contains the acyclic halogen-containing ether represented by.
Examples of the acyclic halogen-containing ether represented by the formula (3) include C ₂ F ₅ OC ₂ F ₅ , C ₃ F ₇ OC ₃ F ₇ , C ₄ F ₉ OC ₄ F ₉ , C ₆ F ₁₃ OC. ₆ F ₁₃ , C ₂ F ₅ OCH ₃ , C ₃ F ₇ OCH ₃ , C ₄ F ₉ OCH ₃ , C ₆ F ₁₃ OCH ₃ , C ₂ F ₅ OCH ₅ , C ₃ F ₇ OCH ₅ , C ₄ F ₉ OC ₂ H ₅ , C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ , CF ₃ CH ₂ OCF ₂ CF ₂ H, CHF ₂ CF ₂ OCH ₂ CF ₃ , CHF ₂ CF ₂ CH ₂ OCF ₂ CF ₂ H, CF ₃ CF ₂ CH ₂ OCF ₂ CHF ₂ , CF ₃ CH ₂ OCF ₂ CHFCF ₃ , and C ₃ HF ₆ CH (CH ₃ ) OC ₃ HF ₆ etc. can be mentioned, and one selected from these. The above is preferable.

The content of the acyclic halogen-containing ether is preferably 0.1% by mass or more and 3% by mass or less, and further preferably 0.3% by mass or more and 2.5% by mass or less, based on the total amount of the non-aqueous electrolyte solution. preferable. When the content of the acyclic halogen-containing ether is 0.1% by mass or more, the stability of the non-aqueous electrolyte solution against oxidative decomposition is enhanced, and the capacity deterioration at high temperature can be suppressed. On the other hand, when the content of the acyclic halogen-containing ether is 3% by mass or less, the solubility of the electrolyte salt can be kept good and the ionic conductivity of the non-aqueous electrolyte solution can be kept high. It is possible to express input / output characteristics. The acyclic halogen-containing ether may be used alone or in combination of two or more.

[Circular phosphazene]
Examples of the cyclic phosphazene include ethoxypentafluorocyclotriphosphazene, diethoxytetrafluorocyclotriphosphazene, phenoxypentafluorocyclotriphosphazene and the like, and one or more selected from these is preferable.

The content of cyclic phosphazene in the non-aqueous electrolyte solution is preferably 0.5% by mass or more and 20% by mass or less based on the total amount of the non-aqueous electrolyte solution. When this value is 0.5% by weight or more, it is possible to suppress the decomposition of the electrolytic solution at high temperature and suppress the gas generation. On the other hand, when this value is 20% by mass or less, the decrease in the ionic conductivity of the electrolytic solution can be suppressed, and high input / output characteristics can be maintained. The content of cyclic phosphazene is more preferably 2% by mass or more and 15% by mass or less, and further preferably 4% by mass or more and 12% by mass or less.
These cyclic phosphazenes may be used alone or in combination of two or more.

[Fluorine-containing cyclic carbonate]
The fluorine-containing cyclic carbonate is preferably used by selecting from fluoroethylene carbonate (FEC) and difluoroethylene carbonate (dFEC) from the viewpoint of compatibility with other non-aqueous solvents.
The content of the cyclic carbonate containing a fluorine atom is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 5% by mass or less, based on the total amount of the non-aqueous electrolytic solution. When the content of the cyclic carbonate containing a fluorine atom is 0.5% by mass or more, a high-quality film can be formed on the negative electrode, and by suppressing the reductive decomposition of the electrolytic solution on the negative electrode, the temperature is high. A storage element with high durability can be obtained. On the other hand, when the content of the cyclic carbonate containing a fluorine atom is 10% by mass or less, the solubility of the electrolyte salt can be kept good and the ionic conductivity of the non-aqueous electrolyte solution can be kept high. It is possible to develop a high degree of input / output characteristics. The above-mentioned cyclic carbonate containing a fluorine atom may be used alone or in combination of two or more.

[Cyclic carbonic acid ester]
For the cyclic carbonate, vinylene carbonate is preferable.
The content of the cyclic carbonate is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 5% by mass or less, based on the total amount of the non-aqueous electrolyte solution. When the content of the cyclic carbonate is 0.5% by mass or more, a high-quality film can be formed on the negative electrode, and by suppressing the reductive decomposition of the electrolytic solution on the negative electrode, the durability at high temperature can be improved. A high power storage element can be obtained. On the other hand, when the content of the cyclic carbonate is 10% by mass or less, the solubility of the electrolyte salt can be kept good and the ionic conductivity of the non-aqueous electrolyte solution can be kept high, so that the input / output is high. It becomes possible to express the property.

[Cyclic carboxylic acid ester]
Examples of the cyclic carboxylic acid ester include gamma-butyrolactone, gamma delta-valerolactone, gamma caprolactone, and epsilon caprolactone, and it is preferable to use one or more selected from these. Of these, gamma-butyrolactone is particularly preferable from the viewpoint of improving battery characteristics resulting from an improvement in the degree of lithium ion dissociation.
The content of the cyclic carboxylic acid ester is preferably 0.5% by mass or more and 15% by mass or less, and more preferably 1% by mass or more and 5% by mass or less, based on the total amount of the non-aqueous electrolyte solution. When the content of cyclic acid anhydride is 0.5% by mass or more, a high-quality film can be formed on the negative electrode, and by suppressing the reductive decomposition of the electrolytic solution on the negative electrode, durability at high temperatures is achieved. A high power storage element can be obtained. On the other hand, when the content of the cyclic carboxylic acid ester is 15% by mass or less, the solubility of the electrolyte salt can be kept good and the ionic conductivity of the non-aqueous electrolyte solution can be kept high. It is possible to develop output characteristics. The above cyclic carboxylic acid ester may be used alone or in combination of two or more.

[Cyclic acid anhydride]
As the cyclic acid anhydride, one or more selected from succinic anhydride, maleic anhydride, citraconic anhydride, and itaconic anhydride are preferable. Among them, it is preferable to select from succinic anhydride and maleic anhydride because the production cost of the electrolytic solution can be suppressed due to industrial availability and the solubility in a non-aqueous electrolytic solution is easy.
The content of the cyclic acid anhydride is preferably 0.5% by mass or more and 15% by mass or less, and more preferably 1% by mass or more and 10% by mass or less, based on the total amount of the non-aqueous electrolyte solution. When the content of cyclic acid anhydride is 0.5% by mass or more, a high-quality film can be formed on the negative electrode, and by suppressing the reductive decomposition of the electrolytic solution on the negative electrode, the durability at high temperature can be improved. A high power storage element can be obtained. On the other hand, when the content of the cyclic acid anhydride is 15% by mass or less, the solubility of the electrolyte salt can be kept good and the ionic conductivity of the non-aqueous electrolyte solution can be kept high, and therefore a high degree of input / output can be maintained. It becomes possible to express the property. The above cyclic acid anhydride may be used alone or in combination of two or more.

[Separator]
The positive electrode precursor and the negative electrode are laminated or wound via a separator, and an electrode laminate or an electrode wound body having the positive electrode precursor, the negative electrode and the separator is formed.
As the separator, a polyethylene microporous film or polypropylene microporous film used for a lithium ion secondary battery, a cellulose non-woven paper used for an electric double layer capacitor, a non-woven fabric containing a polyester resin, or the like can be used. Can be used. A film made of organic or inorganic fine particles may be laminated on one side or both sides of these separators. Further, organic or inorganic fine particles may be contained inside the separator.
The thickness of the separator is preferably 5 μm or more and 35 μm or less. A thickness of 5 μm or more is preferable because self-discharge due to internal micro shorts tends to be small. On the other hand, a thickness of 35 μm or less is preferable because the input / output characteristics of the non-aqueous lithium storage element tend to be high.
The film made of organic or inorganic fine particles is preferably 1 μm or more and 10 μm or less. It is preferable to make the film made of organic or inorganic fine particles having a thickness of 1 μm or more because self-discharge due to internal microshorts tends to be small. On the other hand, a thickness of 10 μm or less is preferable because the input / output characteristics of the non-aqueous lithium storage element tend to be improved.
The porosity of the separator of the present embodiment is preferably 30% to 75%, more preferably 55 to 70%. It is preferable that the porosity is 30% or more from the viewpoint of following the rapid movement of lithium ions during high-speed charging / discharging. On the other hand, setting the porosity to 70% or less is preferable from the viewpoint of improving the film strength, and it is possible to suppress the internal short circuit of the power storage element due to the unevenness of the electrode surface or foreign matter.

[Non-aqueous lithium-type power storage element]
The non-aqueous lithium-type power storage element of the present embodiment is configured such that an electrode laminate or an electrode winding body, which will be described later, is housed in the exterior body together with the non-aqueous electrolyte solution.

[assembly]
The electrode laminate obtained in the cell assembly step is a laminate obtained by laminating a positive electrode precursor and a negative electrode cut into a single-wafer shape via a separator, and connecting a positive electrode terminal and a negative electrode terminal to the laminate. By using the laminated electrode, the distance between the positive electrode and the negative electrode can be made uniform when the electrode is housed in the exterior body, so that the internal resistance can be reduced and the power storage element can be increased in output.
Further, the electrode winding body is formed by winding a positive electrode precursor and a negative electrode via a separator, and connecting a positive electrode terminal and a negative electrode terminal to the winding body. The shape of the electrode winding body may be cylindrical or flat, but it is preferably flat from the viewpoint of improving the filling rate of the power storage element at the time of packing. By using a wound electrode, the time required for the cell assembly process can be shortened, so that the production efficiency is improved.
The method of connecting the positive electrode terminal and the negative electrode terminal is not particularly limited, but a method such as resistance welding or ultrasonic welding is used.

[Exterior body]
As the exterior body, a metal can, a laminated packaging material, or the like can be used.
The metal can is preferably made of aluminum or an aluminum alloy. It is preferable that the lid of the metal can is provided with a safety valve. By installing a safety valve, gas can be released when the internal pressure of the battery rises due to gas generation. By using a metal can, the filling rate of the electrode laminate in the exterior body can be increased, so that the energy density can be improved.
As the laminated packaging material, a film obtained by laminating a metal foil and a resin film is preferable, and a three-layer structure composed of an outer layer resin film / metal foil / interior resin film is exemplified. The outer layer resin film is for preventing the metal foil from being damaged by contact or the like, and a resin such as nylon or polyester can be preferably used. The metal foil is for preventing the permeation of moisture and gas, and a foil of copper, aluminum, stainless steel or the like can be preferably used. Further, the interior resin film is intended to protect the metal foil from the non-aqueous electrolytic solution stored inside and to melt and seal the exterior body at the time of heat sealing, and polyolefins, acid-modified polyolefins and the like can be preferably used. By using the laminated packaging material, the heat dissipation of the power storage element can be improved, and the high temperature durability can be improved.

[Storage in the exterior]
It is preferable that the dried electrode laminated body or electrode wound body is housed in an exterior body typified by a metal can or a laminated packaging material, and sealed with only one opening left. In the case of the electrode wound body, it is preferable to form it flat on a press machine before storing it in the outer body. At this time, it may be heated at the time of pressurization. After forming the wound body flat, it is stored in the outer body. From the viewpoint of improving the adhesion between the exterior body and the electrode unwound body, it is preferable to pressurize and heat the electrode again using a press machine after storage.
The sealing method of the exterior body is not particularly limited, but when a laminated packaging material is used, a method such as heat sealing or impulse sealing is used.

[Drying]
It is preferable that the electrode laminated body or the electrode wound body housed in the outer body is dried to remove the residual solvent. The drying method is not limited, but it is dried by vacuum drying or the like. The residual solvent is preferably 1.5% by mass or less per mass of the positive electrode active material layer or the negative electrode active material layer. If the residual solvent is more than 1.5% by mass, the solvent remains in the system and the self-discharge characteristics or the cycle characteristics are deteriorated, which is not preferable.

[Liquid injection, impregnation, sealing process]
After the assembly process is completed, the non-aqueous electrolyte solution is injected into the electrode laminate or the electrode winding body housed in the exterior body. After the completion of the liquid injection step, it is desirable to further impregnate and sufficiently immerse the positive electrode, the negative electrode, and the separator with a non-aqueous electrolyte solution. When the non-aqueous electrolyte solution is not immersed in at least a part of the positive electrode, the negative electrode, and the separator, the doping proceeds non-uniformly in the lithium doping step described later, so that the resistance of the obtained non-aqueous lithium storage element becomes high. It rises or becomes less durable. The impregnation method is not particularly limited, but for example, the electrode laminate or the electrode winding body after injection is installed in a decompression chamber with the outer body open, and the inside of the chamber is filled with a vacuum pump. It is possible to use a method of reducing the pressure and returning the pressure to atmospheric pressure again. After the impregnation step is completed, when the laminated packaging material is used, the electrode laminated body or the electrode wound body with the outer body open is sealed by sealing while reducing the pressure. When using a metal can, a sealing means such as welding or caulking is used.

[Lithium dope process]
In the lithium doping step, a preferred step is to apply a voltage between the positive electrode precursor and the negative electrode to decompose the lithium compound, thereby decomposing the lithium compound in the positive electrode precursor and releasing lithium ions. By reducing lithium ions at the negative electrode, liotium ions are pre-doped into the negative electrode active material layer.
In this lithium doping step, gas such as CO ₂ is generated due to oxidative decomposition of the lithium compound in the positive electrode precursor. Therefore, when applying a voltage, it is preferable to take measures to release the generated gas to the outside of the exterior body. As this means, for example, a method of applying a voltage with a part of the exterior body opened; a state in which an appropriate gas discharge means such as a gas vent valve or a gas permeation film is previously installed in the part of the exterior body. A method of applying a voltage with the above;

[Aging process]
After the lithium doping step is completed, it is preferable to perform aging on the electrode laminate or the electrode wound body. In the aging step, the solvent in the non-aqueous electrolyte solution is decomposed at the electrode-electrolyte solution interface, and a lithium ion permeable solid polymer film is formed on the electrode.
The aging method is not particularly limited, and for example, a method of reacting a solvent in a non-aqueous electrolyte solution in a high temperature environment can be used.

[Additional charge / discharge process]
In the non-aqueous lithium storage element of the present invention, it is preferable that the electrode laminate or the electrode wound body is additionally charged and discharged after aging. By performing additional charge / discharge, the surface functional groups on the surface of the activated carbon generated by the lithium compound decomposition reaction during the lithium doping step are stabilized, and active points that reversibly interact with Li ions are formed. This makes it possible to store more electricity than the activated carbon originally possessed by the activated carbon in the positive electrode active material, so that the battery capacity can be improved. Further, since the active point that reversibly interacts with the Li ion has a low interaction energy with the Li ion, the diffusion of the Li ion is not hindered even in a low temperature environment, and high output can be maintained. It will be possible.

[Degassing process]
After the aging step is completed, it is preferable to further degas to surely remove the gas remaining in the non-aqueous electrolyte solution, the positive electrode, and the negative electrode. In a state where gas remains in at least a part of the non-aqueous electrolyte solution, the positive electrode, and the negative electrode, ion conduction is inhibited, so that the resistance of the obtained non-aqueous lithium storage element increases.
The method for degassing is not particularly limited, but for example, the electrode laminate or the electrode winding body is installed in the decompression chamber with the exterior body opened, and the inside of the chamber is depressurized by using a vacuum pump. A method or the like can be used.

[Capacitance]
In the present specification, the capacitance F (F) is a value obtained by the following method:
First, in a constant temperature bath in which the cell corresponding to the non-aqueous lithium storage element is set to 25 ° C, constant current charging is performed until the current value of 20C reaches 4.2V, and then a constant voltage of 4.2V is applied. The constant voltage charging to be applied is performed for a total of 30 minutes. After that, let Q be the capacity when a constant current discharge is performed with a current value of 2C up to 2.2V. It means a value calculated by F = Q / (4.2-2.2) using the Q obtained here.

[Electric energy]
In the present specification, the electric energy E (Wh) is a value obtained by the following method:
It refers to a value calculated by F × (4.2-2.2) / 2/3600 using the capacitance F (F) calculated by the method described above.

[volume]
The volume of the non-aqueous lithium-type power storage element is not particularly specified, but the region in which the positive electrode active material layer and the negative electrode active material layer are stacked in the electrode laminate or the electrode wound body is housed by the exterior body. Refers to the volume of the part.
For example, in the case of an electrode laminate or an electrode wound body housed by a laminated film, a region of the electrode laminated body or the electrode wound body in which the positive electrode active material layer and the negative electrode active material layer are present is cup-molded. Although housed in the laminated film, the volume (V11) of the non-aqueous lithium storage element includes the outer dimension length (l1), the outer dimension width (w1), and the laminated film of the cup molded portion. It is calculated by V11 = l1 × w1 × t1 according to the thickness (t1) of the non-aqueous lithium-type power storage element.
In the case of an electrode laminate or an electrode winding body housed in a square metal can, the volume of the non-aqueous lithium-type power storage element is simply the volume of the outer size of the metal can. That is, the volume (V22) of this non-aqueous lithium-type power storage element depends on the outer dimension length (l2), outer dimension width (w2), and outer dimension thickness (t2) of the square metal can, and V22 = l2 × w2. It is calculated by × t2.
Further, even in the case of an electrode winding body housed in a cylindrical metal can, the volume of the non-aqueous lithium-type power storage element is the volume of the outer dimension of the metal can. That is, the volume (V33) of this non-aqueous lithium type power storage element is V33 = 3.14 × r × depending on the outer dimension radius (r) and the outer dimension length (l3) of the bottom surface or the upper surface of the cylindrical metal can. It is calculated by r × l3.

[Energy density]
In the present specification, the energy density is a value obtained by the formula of E / Vi (Wh / L) using the electric energy E and the volume Vii (i = 1, 2, 3).

[Room temperature internal resistance]
In the present specification, the room temperature internal resistance Ra (Ω) is a value obtained by the following method:
First, the cell corresponding to the non-aqueous lithium-type power storage element is charged with a constant current in a constant temperature bath set at 25 ° C. until it reaches 4.2 V with a current value of 20 C, and then a constant voltage of 4.2 V is applied. Perform constant voltage charging for a total of 30 minutes. Subsequently, a constant current discharge is performed up to 2.2 V at a current value of 20 C to obtain a discharge curve (time-voltage). In this discharge curve, when the voltage at the discharge time = 0 second obtained by extrapolating from the voltage values at the time points of the discharge time of 2 seconds and 4 seconds is set to Eo, the voltage drop ΔE = 4.2. It is a value calculated by Eo and Ra = ΔE / (20C (current value A)).

[Low temperature internal resistance]
As used herein, the low temperature internal resistance Rc is a value obtained by the following method:
First, the cell corresponding to the non-aqueous lithium-type power storage element is left in a constant temperature bath set at −30 ° C. for 2 hours. After that, while keeping the constant temperature bath at -30 ° C, constant current charging is performed with a current value of 1.0 C until it reaches 4.2 V, and then constant voltage charging with a constant voltage of 4.2 V is applied for a total of 2 Do time. Subsequently, a constant current discharge is performed up to 2.2 V with a current value of 10 C to obtain a discharge curve (time-voltage). In this discharge curve, when the voltage at the discharge time = 0 second obtained by extrapolating from the voltage values at the time points of the discharge time of 2 seconds and 4 seconds is set to Eo, the voltage drop ΔE = 4.2. It is a value calculated by Eo and Rc = ΔE / (10C (current value A)).

[High temperature storage test]
In the present specification, the amount of gas generated during the high temperature storage test, the room temperature internal resistance increase rate after the high temperature storage test, and the capacity retention rate are measured by the following methods:
First, the cell corresponding to the non-aqueous lithium-type power storage element is charged with a constant current in a constant temperature bath set at 25 ° C. until it reaches 4.2 V with a current value of 100 C, and then a constant voltage of 4.2 V is applied. Perform constant voltage charging for 10 minutes. Then, the cell is stored in a 60 ° C environment, taken out from the 60 ° C environment every two weeks, the cell voltage is charged to 4.2 V in the above-mentioned charging step, and then the cell is stored again in the 60 ° C environment. .. This step is repeated, and the cell volume Va before the start of storage and the cell volume Vb 2 months after the storage test are measured by the Archimedes method. Let Vb-Va be the amount of gas generated when stored for 2 months at a cell voltage of 4.2 V and an environmental temperature of 60 ° C.
For the cell after the high temperature storage test, the resistance value obtained by using the same measurement method as the normal temperature internal resistance is measured by using the same measurement method as the normal temperature internal resistance Rb after the high temperature storage test and the capacitance. When the obtained capacitance is the capacitance Fb after the high temperature storage test, the rate of increase in the normal temperature internal resistance after the high temperature storage test is Rb / Ra, and the high temperature storage test is started with respect to the normal temperature internal resistance Ra before the start of the high temperature storage test. The capacitance retention rate after the high temperature storage test for the previous capacitance Fa can be calculated by Fb / Fa.

In the non-aqueous lithium-type power storage element according to the present embodiment, the initial room temperature internal resistance is Ra (Ω), the capacitance is F (F), the electric power is E (Wh), and the volume of the power storage element is V (L). When, the following:
(A) The product Ra / F of Ra and F is 0.3 or more and 3.0 or less; and (b) E / V is 20 or more and 80 or less; and (c) Rc / Ra is 30 or less. be;
It is preferable that the above conditions are satisfied at the same time.

Regarding (a), Ra and F are preferably 3.0 or less, more preferably 2.6 or less, and further, from the viewpoint of developing sufficient charge capacity and discharge capacity for a large current. It is preferably 2.4 or less. When Ra / F is not more than the above upper limit value, a non-aqueous lithium storage element having excellent input / output characteristics can be obtained. Therefore, by combining a power storage system using a non-aqueous lithium-type power storage element with, for example, a high-efficiency engine, it is possible to sufficiently withstand a high load applied to the non-aqueous lithium-type power storage element, which is preferable.

Regarding (b), the E / V is preferably 20 or more, more preferably 25 or more, and further preferably 30 or more, from the viewpoint of developing a sufficient charge capacity and discharge capacity. When the E / V is equal to or higher than the above lower limit value, a power storage element having an excellent volumetric energy density can be obtained. Therefore, when a power storage system using a power storage element is used in combination with, for example, an engine of an automobile, it is possible to install the power storage system in a limited narrow space in the automobile, which is preferable.

Regarding (c), Rc / Ra is preferably 30 or less, more preferably 26 or less, and further preferably 26 or less, from the viewpoint of developing sufficient charge capacity and discharge capacity even in a low temperature environment of −30 ° C. It is preferably 22 or less. When Rc / Ra is not more than the above upper limit value, a power storage element having excellent output characteristics can be obtained even in a low temperature environment. Therefore, when starting an engine of an automobile, a motorcycle, or the like in a low temperature environment, it is possible to obtain a power storage element that gives sufficient electric power to drive a motor.

The non-aqueous lithium storage element according to this embodiment is
The initial room temperature internal resistance is Ra (Ω), the capacitance is Fa (F), the cell voltage is 4.2 V, and the internal resistance at 25 ° C after storage at an ambient temperature of 60 ° C for 2 months is Rb (Ω), static. When the capacitance is Fb (F) and the internal resistance at an ambient temperature of -30 ° C is Rc, the following requirements (d), (e) and (f) are:
(D) Rb / Ra is 0.8 or more and 3.0 or less;
(E) Fb / Fa is 0.5 or more and 1.2 or less; and (f) The amount of gas generated when stored for 2 months at a cell voltage of 4.2 V and an environmental temperature of 60 ° C. is 30 × at 25 ° C. 10 ^-3 cc / F or less;
It is more preferable to satisfy at the same time.

Regarding (d), Rb / Ra is preferably 3.0 or less from the viewpoint of developing sufficient charge capacity and discharge capacity for a large current when exposed to a high temperature environment for a long time. , More preferably 2.0 or less, still more preferably 1.5 or less. When Rb / Ra is not more than the above upper limit value, stable and excellent output characteristics can be obtained for a long period of time, which leads to a long life of the device.

Regarding (e), Fb / Fa is 0.5 or more from the viewpoint of developing sufficient charge capacity and discharge capacity when exposed to a high temperature environment for a long time and maintaining the function of the power storage system. It is preferable, more preferably 0.6 or more, still more preferably 0.7 or more. If Fb / Fa is equal to or higher than the above lower limit value, a constant power can be stably obtained for a long period of time, which leads to a longer life of the device.

Regarding (f), the amount of gas generated when stored for 2 months at a cell voltage of 4.2 V and an environmental temperature of 60 ° C. is 25 ° C. from the viewpoint that the generated gas does not deteriorate the characteristics of the element. The value measured in 1 is preferably 30 × 10 ^-3 cc / F or less, more preferably 20 × 10 ^-3 cc / F or less, and further preferably 15 × 10 -3 cc / F or less. When the amount of gas generated under the above conditions is not more than the above upper limit value, there is no possibility that the cell will expand due to gas generation even when the device is exposed to a high temperature for a long period of time. Therefore, it is possible to obtain a power storage element having sufficient safety and durability.

[Use of non-aqueous alkali metal type power storage element]
A power storage module can be manufactured by connecting a plurality of non-aqueous alkali metal type power storage elements according to the present embodiment in series or in parallel. Further, since the non-aqueous alkali metal type power storage element and the power storage module of the present embodiment can achieve both high input / output characteristics and safety at high temperature, a power regeneration assist system, a power load leveling system, and no power failure occur. It can be used in power supply systems, contactless power supply systems, energy harvest systems, power storage systems, electric power steering systems, emergency power supply systems, in-wheel motor systems, idling stop systems, quick charging systems, smart grid systems, and the like.

The power storage system is preferably used for natural power generation such as solar power generation or wind power generation, the power load leveling system is preferably used for microgrids, and the non-disruptive power supply system is preferably used for production equipment in factories. In the non-contact power supply system, the non-aqueous alkali metal energy storage element is used for leveling voltage fluctuations such as microwave power transmission or electric field resonance and for storing energy. In the energy harvest system, the non-aqueous alkali metal energy storage element is used. In order to use the electric power generated by vibration power generation or the like, each is suitably used.
In a power storage system, a plurality of non-aqueous alkali metal storage elements are connected in series or in parallel as a cell stack, or a non-aqueous alkali metal storage element is connected to a lead battery, a nickel hydrogen battery, and a lithium ion secondary battery. Batteries or fuel cells are connected in series or in parallel.

Further, the non-aqueous lithium power storage element according to the present embodiment can achieve both high input / output characteristics and safety at high temperatures, and therefore, for example, an electric vehicle, a plug-in hybrid vehicle, a hybrid vehicle, an electric motorcycle, etc. It can be mounted on vehicles such as hybrid excavators. The power regeneration assist system, the electric power steering system, the emergency power supply system, the in-wheel motor system, the idling stop system, or a combination thereof described above are suitably mounted on the vehicle.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Example 1)

<Crushing lithium carbonate>
Using lithium carbonate having a BET specific surface area of 0.9 m ² / g and a pore volume P of 0.001 cc / g, 15 parts by mass of lithium carbonate and 85 parts by mass of IPA (isopropanol) were mixed with a homodisper. A lithium carbonate suspension was obtained. This lithium carbonate suspension was pulverized with a wet bead mill for 2 hours to obtain a lithium compound-containing slurry. The obtained lithium compound-containing slurry was heated to 50 ° C. under reduced pressure with a heating mixer and dried while stirring for 3 hours to prepare lithium carbonate. When the average particle size of the obtained lithium carbonate was measured to determine the charged lithium carbonate particle size, it was 0.5 μm.

<Preparation of positive electrode active material>
[Preparation of positive electrode active material A]
The crushed coconut shell carbide was carbonized in nitrogen at 500 ° C. for 3 hours in a small carbonization furnace to obtain carbonized material. The obtained carbide was put into an activation furnace, and 1 kg / h of steam was introduced into the activation furnace in a state of being heated in the preheating furnace, and the temperature was raised to 900 ° C. over 8 hours for activation. The activated carbonized material was taken out and cooled in a nitrogen atmosphere to obtain activated activated carbon. The obtained activated carbon was washed with water for 10 hours and then drained. Then, after drying for 10 hours in an electric dryer kept at 115 ° C., activated carbon A was obtained by pulverizing with a ball mill for 1 hour.
The average particle size of this activated carbon A was 4.2 μm as a result of measuring the average particle size using a laser diffraction type particle size distribution measuring device (SALD-2000J) manufactured by Shimadzu Corporation. In addition, the pore distribution was measured using a pore distribution measuring device (AUTOSORB-1 AS-1-MP) manufactured by Yuasa Ionics. As a result, the BET specific surface area was 2360 m ² / g, the mesopore amount (V1) was 0.52 cc / g, the micropore amount (V2) was 0.88 cc / g, and V1 / V2 = 0.59.

[Preparation of positive electrode active material B]
The phenol resin was carbonized in a firing furnace at 600 ° C. for 2 hours in a nitrogen atmosphere, then pulverized with a ball mill and classified to obtain a carbide having an average particle size of 7 μm. This carbide and KOH were mixed at a mass ratio of 1: 5, and activated by heating in a firing furnace at 800 ° C. for 1 hour in a nitrogen atmosphere. Then, activated carbon B was obtained by stirring and washing in dilute hydrochloric acid adjusted to a concentration of 2 mol / L for 1 hour, boiling and washing with distilled water until the pH became stable between 5 and 6, and then drying.
The pore distribution of this activated carbon B was measured using a pore distribution measuring device (AUTOSORB-1 AS-1-MP) manufactured by Yuasa Ionics. As a result, the BET specific surface area was 3627 m ² / g, the mesopore amount (V1) was 1.50 cc / g, the micropore amount (V2) was 2.28 cc / g, and V1 / V2 = 0.66.

<Manufacturing of positive electrode precursors A and B>
The activated carbon A obtained above was used as a positive electrode active material to produce a positive electrode precursor.
87.5 parts by mass of activated carbon A, 30 parts by mass of lithium carbonate having an average particle size of 0.5 μm as a lithium compound, 3.0 parts by mass of KB (Ketchen Black), and 1.5 parts by mass of PVP (polyvinylpyrrolidone). , And PVDF (polyfluorovinylidene) in an amount of 8.0 parts by mass, and NMP (N-methylpyrrolidone) were mixed, and the mixture was mixed with a thin film swirling high-speed mixer fill mix manufactured by PRIMIX at a peripheral speed of 17 m / s. The coating liquid was obtained by dispersing under the conditions. The viscosity (ηb) and TI value of the obtained coating liquid were measured using an E-type viscometer TVE-35H manufactured by Toki Sangyo Co., Ltd. As a result, the viscosity (ηb) was 2,700 mPa · s, and the TI value was 3.5. In addition, the degree of dispersion of the obtained coating liquid was measured using a grain gauge manufactured by Yoshimitsu Seiki Co., Ltd. As a result, the particle size was 35 μm. The above coating liquid is applied to one or both sides of a 15 μm thick aluminum foil using a die coater manufactured by Toray Engineering Co., Ltd. under the condition of a coating speed of 1 m / s, and hot air is applied at a drying temperature of 100 ° C. as a primary drying step. It was dried to obtain a positive electrode precursor. The obtained positive electrode precursor was pressed using a roll press machine under the conditions of a pressure of 4 kN / cm and a surface temperature of the pressed portion of 25 ° C. Then, as a secondary drying step, the film thickness of the positive electrode active material layer of the positive electrode precursor obtained by vacuum drying at a drying temperature of 200 ° C. was measured using a film thickness meter Linear Gauge Sensor GS-551 manufactured by Ono Keiki Co., Ltd. It was obtained by subtracting the thickness of the aluminum foil from the average value of the thickness measured at any 10 points on the body. As a result, the film thickness of the positive electrode active material layer was 170 μm per one side. As a result of calculating the basis weight by the above method, the basis weight of the positive electrode active material layer was 50 g · m ^-2 per one side.
Hereinafter, the single-sided positive electrode precursor and the double-sided positive electrode precursor using the activated carbon A are referred to as a single-sided positive electrode precursor A and a double-sided positive electrode precursor A (collectively, “positive electrode precursor A”). Similarly, the single-sided positive electrode precursor and the double-sided positive electrode precursor produced by using the activated carbon B are referred to as a single-sided positive electrode precursor B and a double-sided positive electrode precursor B (collectively, “positive electrode precursor B”).

<Preparation of positive electrode precursor C containing transition metal oxide>
43.1 parts by mass of activated carbon A, 14.4 parts by mass of LiFePO ₄ having an average particle diameter of 3.5 μm as a lithium transition metal oxide, 30.0 parts by mass of lithium carbonate, and 3.0 parts by mass of Ketjen Black. , PVP (polyvinylpyrrolidone) by 1.5 parts by mass, PVDF (polyvinylidene fluoride) by 8.0 parts by mass, and NMP (N-methyl-2-) so that the weight ratio of solid content is 24.5%. Pyrrolidone) is mixed, and the mixture is dispersed for 3 minutes at a peripheral speed of 20 m / s using a thin film swirl type high-speed mixer “Fillmix (registered trademark)” manufactured by PRIMIX to obtain a positive electrode coating liquid 1. rice field.
The viscosity (ηb) and TI value of the obtained positive electrode coating liquid 1 were measured using an E-type viscometer TVE-35H manufactured by Toki Sangyo Co., Ltd. As a result, the viscosity (ηb) was 2,690 mPa · s, and the TI value was 6.6. Further, the degree of dispersion of the obtained positive electrode coating liquid 1 was measured using a grain gauge manufactured by Yoshimitsu Seiki Co., Ltd. As a result, the particle size was 23 μm.
Using a double-sided die coater manufactured by Toray Engineering Co., Ltd., the positive electrode coating liquid 1 was applied to both sides of a 15 μm-thick aluminum foil at a coating speed of 1 m / s, and the temperatures of the drying furnaces were set to 70 ° C and 90 ° C. , 110 ° C. and 130 ° C. in this order, and then primary drying with an IR heater to obtain a positive electrode precursor C. The obtained positive electrode precursor C was pressed using a roll press machine under the conditions of a pressure of 6 kN / cm and a surface temperature of the pressed portion of 25 ° C. Then, as a secondary drying step, the total thickness of the positive electrode precursor C obtained by vacuum drying at a drying temperature of 200 ° C. was measured by using a film thickness meter Liner Gauge Sensor GS-551 manufactured by Ono Keiki Co., Ltd. to obtain the positive electrode precursor C. Measurements were made at any 10 locations. The film thickness of the positive electrode active material layer obtained by subtracting the thickness of the aluminum foil was 70 μm per side. As a result of calculating the basis weight by the above method, the basis weight of the positive electrode active material layer was 45 g · m ^-2 per one side.

<Preparation of negative electrode active material>
[Preparation of negative electrode active material A]
A stainless steel bat containing 150 g of artificial graphite having an average particle diameter of 6.2 μm and a BET specific surface area of 7.2 m ² / g in a stainless steel mesh cage and 15 g of coal-based pitch (softening point: 65 ° C.). Both were placed in an electric furnace (effective size in the furnace 300 mm × 300 mm × 300 mm). This was heated to 1,250 ° C. in a nitrogen atmosphere in 8 hours and kept at the same temperature for 4 hours to cause a thermal reaction to obtain a negative electrode active material A. The obtained negative electrode active material A was cooled to 60 ° C. by natural cooling, and then taken out from the electric furnace.
For the obtained negative electrode active material A, the average particle size and the BET specific surface area were measured by the same method as described above. As a result, the average particle size was 6.4 μm and the BET specific surface area was 5.2 m ² / g.

<Manufacturing of negative electrode A>
Next, a negative electrode was manufactured using the negative electrode active material A.
85 parts by mass of negative electrode active material A, 10 parts by mass of acetylene black, 5 parts by mass of PVdF (polyvinylidene fluoride), and NMP (N-methylpyrrolidone) are mixed and mixed with a thin film swirl type high speed manufactured by PRIMIX. Using a mixer fill mix, a coating liquid was obtained by dispersing under the condition of a peripheral speed of 15 m / s. The viscosity (ηb) and TI value of the obtained coating liquid were measured using an E-type viscometer TVE-35H manufactured by Toki Sangyo Co., Ltd. As a result, the viscosity (ηb) was 2,789 mPa · s, and the TI value was 4.3. The above coating liquid was applied to both sides of an electrolytic copper foil having a thickness of 10 μm and having no through holes using a die coater manufactured by Toray Engineering Co., Ltd. at a coating speed of 1 m / s, and dried at a drying temperature of 85 ° C. Obtained a negative electrode A. The obtained negative electrode A was pressed using a roll press machine under the conditions of a pressure of 4 kN / cm and a surface temperature of the pressed portion of 25 ° C. The film thickness of the negative electrode active material layer of the negative electrode A obtained above was measured from the average value of the thickness measured at any 10 points of the negative electrode A using a film thickness meter Linear Gauge Sensor GS-551 manufactured by Ono Keiki Co., Ltd. , Calculated by subtracting the thickness of the copper foil. As a result, the basis weight per one side of the negative electrode active material layer of the negative electrode A was 30 g / m ² , and the film thickness was 40 μm.

[Measurement of capacity per unit weight of negative electrode]
One of the obtained negative electrode A was cut into a size of 1.4 cm × 2.0 cm (2.8 cm ² ), and one layer of the negative electrode active material layer coated on both sides of the copper foil was formed with a spatula, a brush, and a brush. Was removed to make a working electrode. LiPF ₆ was dissolved at a concentration of 1.0 mol / L in a 1: 1 mixed solvent having a volume ratio of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) as an electrolytic solution, using metallic lithium as a counter electrode and a reference electrode, respectively. An electrochemical cell was made in an argon box using a non-aqueous solution.
The initial charge capacity of the obtained electrochemical cell was measured by the following procedure using a charging / discharging device (TOSCAT-3100U) manufactured by Toyo System Co., Ltd.
After constantly charging the electrochemical cell at a temperature of 25 ° C. at a current value of 0.5 mA / cm ² until the voltage value reaches 0.01 V, the current value further becomes 0.01 mA / cm ² . Constant voltage charging was performed until. When the charge capacity at the time of constant current charging and constant voltage charging was evaluated as the initial charge capacity, the capacity per unit mass of the negative electrode A (lithium ion doping amount) was 400 mAh / g.

[Preparation of negative electrode active material B]
100 parts by weight of carbon black (CB1) with an average particle diameter of 30 nm and a BET specific surface area of 254 m ² / g, and 50 parts by weight of an optically isotropic pitch (P1) with a softening point of 110 ° C. and a metaphase amount (QI amount) of 13%. The kneaded product obtained by kneading and kneaded with a heating kneader was calcined at 1,000 ° C. in a non-oxidizing atmosphere. The obtained fired product was pulverized to an average particle size (D50) of 7 μm to obtain a composite porous material B as a negative electrode active material B. The BET specific surface area of the obtained negative electrode active material B was measured by the same method as described above. As a result, the BET specific surface area was 180 m ² / g.

<Manufacturing of negative electrode B>
The negative electrode B was manufactured in the same manner as the negative electrode A except that the negative electrode active material B obtained above was used as the negative electrode active material. As a result of measuring the doping amount of lithium ions in the same manner as the negative electrode A, the negative electrode B was 1300 mAh / g.

<Manufacturing of negative electrode C containing two types of active materials>
76 parts by mass of the negative electrode active material A, 4 parts by mass of the negative electrode active material B, 8 parts by mass of acetylene black, 12 parts by mass of PVdF (polyfluorinated vinylidene), and NMP (N-methylpyrrolidone) are mixed. Was dispersed under the condition of a peripheral speed of 15 m / s using a thin film swirl type high-speed mixer fill mix manufactured by PRIMIX to obtain a coating liquid. The viscosity (ηb) and TI value of the obtained coating liquid were measured using an E-type viscometer TVE-35H manufactured by Toki Sangyo Co., Ltd. As a result, the viscosity (ηb) was 2,789 mPa · s, and the TI value was 4.3. The above coating liquid was applied to both sides of an electrolytic copper foil having a thickness of 10 μm and having no through holes using a die coater manufactured by Toray Engineering Co., Ltd. at a coating speed of 1 m / s, and dried at a drying temperature of 85 ° C. Obtained a negative electrode C. The obtained negative electrode C was pressed using a roll press machine under the conditions of a pressure of 4 kN / cm and a surface temperature of the pressed portion of 25 ° C. The film thickness of the negative electrode active material layer of the negative electrode C obtained above was measured from the average value of the thickness measured at any 10 points of the negative electrode C using a film thickness meter Linear Gauge Sensor GS-551 manufactured by Ono Keiki Co., Ltd. , Calculated by subtracting the thickness of the copper foil. As a result, the basis weight per one side of the negative electrode active material layer of the negative electrode C was 28 g / m ² , and the film thickness was 40 μm.

<Preparation of electrolytic solution>
As an organic solvent, a mixed solvent of ethylene carbonate (EC): dimethyl carbonate (DMC): methyl ethyl carbonate (EMC) = 34: 44: 22 (volume ratio) was used, and LiN (SO ₂ F) was used with respect to the total electrolytic solution. Each electrolyte salt was dissolved so that the concentration ratio of ₂ and LiPF ₆ was 25:75 (molar ratio) and the sum of the concentrations of LiN (SO ₂ F) ₂ and LiPF ₆ was 1.2 mol / L. ..
The concentrations of LiN (SO ₂ F) ₂ and LiPF ₆ in the electrolytic solution prepared here were 0.3 mol / L and 0.9 mol / L, respectively. Further, as an additive, ethylene sulfate in an amount of 0.1% by mass with respect to the total electrolytic solution was dissolved to obtain a non-aqueous electrolytic solution 1.

<Assembly of power storage element>
The obtained double-sided negative electrode A and double-sided positive electrode precursor A were cut into 10 cm × 10 cm (100 cm ² ). A single-sided positive electrode precursor is used for the uppermost surface and the lowermost surface, and 21 double-sided negative electrodes and 20 double-sided positive electrode precursors are used. The microporous membrane separator A was sandwiched and laminated.
<Welding of terminals>
Then, the negative electrode terminal and the positive electrode terminal were connected to the negative electrode and the positive electrode precursor by ultrasonic welding to form an electrode laminate. This electrode laminate was subjected to 60 hr. At 80 ° C. and 50 Pa. Was vacuum dried. This electrode laminate is inserted into an exterior body made of a laminated packaging material in a dry environment with a dew point of −45 ° C., and the three outer bodies of the electrode terminal portion and the bottom portion are heated at 180 ° C., 20 sec, and 1.0 MPa. Sealed. A non-aqueous lithium-type power storage element was assembled by injecting a non-aqueous electrolyte solution and sealing the exterior body.

<Liquid injection, impregnation, sealing process of power storage element>
About 80 g of the non-aqueous electrolyte solution 1 was injected into the electrode laminate housed in the aluminum laminate packaging material under a dry air environment having a temperature of 25 ° C. and a dew point of −40 ° C. or lower under atmospheric pressure. Subsequently, the non-aqueous lithium-type power storage element was placed in the decompression chamber, the pressure was reduced from normal pressure to −87 kPa, the pressure was returned to atmospheric pressure, and the mixture was allowed to stand for 5 minutes. Then, after reducing the pressure from normal pressure to −87 kPa, the process of returning to atmospheric pressure was repeated 4 times, and then the mixture was allowed to stand for 15 minutes. Further, the pressure was reduced from normal pressure to −91 kPa, and then the pressure was returned to atmospheric pressure. Similarly, the steps of depressurizing and returning to atmospheric pressure were repeated 7 times in total (decompressed to -95, -96, -97, -81, -97, -97, and -97 kPa, respectively). By the above steps, the electrode laminate was impregnated with the non-aqueous electrolyte solution.
Then, the non-aqueous lithium-type power storage element was placed in a vacuum sealing machine, and the aluminum laminate packaging material was sealed by sealing at 180 ° C. for 10 seconds at a pressure of 0.1 MPa with the pressure reduced to −95 kPa.

<Lithium dope process>
For the obtained non-aqueous lithium type power storage element, a charging / discharging device (TOSCAT-3100U) manufactured by Toyo System Co., Ltd. is used, and the voltage is fixed until the voltage reaches 4.4 V at a current value of 0.7 A in a 25 ° C environment. After the current charge, the initial charge was continuously performed by the method of continuing the 4.4 V constant voltage charge for 10 hours, and the negative electrode was lithium-doped.

<Aging process>
The non-aqueous lithium-type power storage element after lithium doping is subjected to constant current discharge at 0.7 A until the voltage reaches 3.0 V, and then constant current constant voltage charge up to 4.0 V for 1 hour. The voltage was adjusted to 4.0V. Subsequently, the non-aqueous lithium-type power storage element was stored in a constant temperature bath at 60 ° C. for 20 hours.
<Additional charge / discharge process>
After aging, the non-aqueous lithium-type power storage element is discharged at 10 A at 10 A with a constant current until it reaches a voltage of 2.5 V, then charged at 10 A from 2.5 V to 3.9 V, and then charged at 10 A. The charge / discharge process of discharging to 2.5 V was repeated 5 times.

<Degassing process>
A part of the aluminum laminate packaging material was opened in a dry air environment with a temperature of 25 ° C. and a dew point of −40 ° C. for the non-aqueous lithium-type power storage element after the additional charge / discharge step. Subsequently, the non-aqueous lithium-type power storage element was placed in the decompression chamber, and the pressure was reduced from atmospheric pressure to -80 kPa using a diaphragm pump (N816.3KT.45.18) manufactured by KNF for 3 minutes. The process of returning to atmospheric pressure over 3 minutes was repeated a total of 3 times. Then, a non-aqueous lithium-type power storage element was placed in a vacuum sealing machine, the pressure was reduced to −90 kPa, and then the aluminum laminate packaging material was sealed by sealing at 200 ° C. for 10 seconds at a pressure of 0.1 MPa.

により、正極活物質層に堆積する各化合物の、正極活物質層の単位質量当たりの存在量（ｍｏｌ／ｇ）を求めた。
なお、抽出に用いた正極活物質層の質量は、以下の方法によって求めた。
重水抽出後に残った正極の集電体から正極活物質層を剥がし取り、該剥がし取った正極活物質層を、水洗した後、真空乾燥した。真空乾燥して得た正極活物質層を、ＮＭＰ又はＤＭＦにより洗浄した。続いて、得られた正極活物質層を再度真空乾燥した後、秤量することにより、抽出に用いた正極活物質層の質量を調べた。 <Analysis of positive electrode active material layer and negative electrode active material layer>
After adjusting the completed non-aqueous lithium-type power storage element to 2.9V, disassemble it in an Ar box installed in a room at 23 ° C and controlled at a dew point of -90 ° C or less and an oxygen concentration of 1 ppm or less, and take out the positive electrode. rice field. The removed positive electrode was immersed and washed with dimethyl carbonate (DMC), and then vacuum dried in a side box while maintaining no exposure to the atmosphere.
The dried positive electrode was transferred from the side box to the Ar box while being not exposed to the atmosphere, and immersed in heavy water for extraction to obtain a positive electrode extract. The extract was analyzed by IC / MS, and the concentration A (mol / ml) of each compound in the obtained positive electrode extract, the volume B (ml) of the heavy water used for the extraction, and the positive activity used for the extraction. From the mass C (g) of the material layer, the following formula 1:

The abundance (mol / g) of each compound deposited on the positive electrode active material layer per unit mass of the positive electrode active material layer was determined.
The mass of the positive electrode active material layer used for extraction was determined by the following method.
The positive electrode active material layer was peeled off from the positive electrode current collector remaining after heavy water extraction, and the peeled positive electrode active material layer was washed with water and then vacuum dried. The positive electrode active material layer obtained by vacuum drying was washed with NMP or DMF. Subsequently, the obtained positive electrode active material layer was vacuum-dried again and then weighed to examine the mass of the positive electrode active material layer used for extraction.

The analysis method of the extract is shown below.
(IC / MS)
The IC / MS measurement conditions of the positive electrode extract are shown below.
<IC>
Equipment: Tosoh, IC-2001
Separation column: Tosoh, TSKgel Super IC-AP (4.6 mm ID x 75 mm)
Eluent: 1.7 mM NaHCO ₃ + 1.8 mM Na ₂ CO ₃
Flow rate: 0.8 mL / min
Constant temperature bath: 40 ° C
Injection volume: 30 μL
<MS>
Equipment: Waters, Synapt G2
Ionization: Electrospray ionization (ESI)
Scan range: m / z 50-179

When IC / MS measurement of the positive electrode extract was carried out under the above conditions, HOCH ₂ CH ₂ OSO _3- ^, CH ₃ CH ₂ OSO _3- ^{, and} CH ₃ OSO _3- were mainly detected. Next, the concentration A of each compound was determined by semi-quantification by an absolute calibration curve method using a commercially available reagent CH ₃ CH ₂ CH ₂ SO ₃ Na.
From the IC / MS analysis results, it is determined whether the detected HOCH ₂ CH ₂ OSO ₃ ⁻ is derived from LiOCH ₂ CH ₂ OSO ₃ Li or HOCH ₂ CH ₂ OSO ₃ Li or HOCH ₂ CH ₂ OSO ₃ H. It cannot be determined whether CH ₃ CH ₂ OSO ₃ ⁻ is derived from CH ₃ CH ₂ OSO ₃ Li or CH ₃ CH ₂ OSO ₃ ⁻ H, and CH ₃ OSO ₃ ⁻ is derived from CH ₃ OSO ₃ Li. It cannot be determined whether it is derived from CH ₃ OSO ₃ H. However, considering the presence of the electrolyte, they were treated as LiOCH ₂ CH ₂ OSO ₃ Li-derived compounds, CH ₃ CH ₂ OSO ₃ Li-derived compounds, and CH ₃ OSO ₃ Li-derived compounds, respectively.

Based on the concentration of each compound in the extract obtained by the above (IC / MS) analysis, the volume of heavy water used for extraction, and the mass of the positive electrode active material layer used for extraction, the positive positive substance layer has a positive electrode. XOCH ₂ CH ₂ OSO ₃ X (compound (A)) is 0.50 × ^10-5 mol / g, CH ₃ CH ₂ OSO ₃ X (compound (B)) is 0.20 × per unit mass of the active material layer. ^10-5 mol / g and CH ₃ OSO ₃ X (compound (C)) were present at 0.20 × ^10-5 mol / g.
The total amount of the compounds (A) to (C) contained in the positive electrode active material layer was 0.9 × ^10-5 mol / g.
Similarly, when the total amount of the compounds (A) to (C) contained in the negative electrode active material layer was determined, it was 0.4 × 10 ^-5 mol / g.

[Calculation of energy density]
The power storage element obtained in the above step reaches 4.2V at a current value of 2C using a charging / discharging device (5V, 360A) manufactured by Fujitsu Telecom Networks Limited in a constant temperature bath set at 25 ° C. Constant current charging was performed until the voltage was increased, and then constant voltage charging was performed for a total of 30 minutes by applying a constant voltage of 4.2 V. After that, let Q be the capacitance when constant current discharge is performed with a current value of 2C up to 2.2V, and use the capacitance F (F) calculated by F = Q / (4.2-2.2). hand,
The energy density was calculated by E / V = F × (4.22-2-22) / 2/3600 / V and found to be 47.9 Wh / L.

[Calculation of Ra / F]
The power storage element obtained in the above step reaches 4.2V at a current value of 20C using a charging / discharging device (5V, 360A) manufactured by Fujitsu Telecom Networks Co., Ltd. in a constant temperature bath set at 25 ° C. The constant current charge is performed until the current value is increased, and then the constant voltage charge of applying a constant voltage of 4.2 V is performed for a total of 30 minutes, and then the constant current discharge is performed at a current value of 20 C to 2.2 V, and the discharge curve ( Time-voltage) was obtained. In this discharge curve, the voltage at the discharge time = 0 second obtained by extrapolating from the voltage values at the time points of the discharge time of 2 seconds and 4 seconds is defined as Eo, the voltage drop ΔE = 4.2-Eo, and. The room temperature internal resistance Ra was calculated by R = ΔE / (20C (current value A)).
The product Ra · F of the capacitance F and the internal resistance Ra at 25 ° C. was 1.92 ΩF.

[Calculation of Rc / Ra]
The power storage element obtained in the above step was left in a constant temperature bath set at -30 ° C for 2 hours, and then a charging / discharging device (5V, 5V, manufactured by Fujitsu Telecom Networks Limited) was maintained at the constant temperature bath at -30 ° C. Using 360A), constant current charging was performed with a current value of 1.0C until 4.2V was reached, followed by constant voltage charging to which a constant voltage of 4.2V was applied for a total of 2 hours. Subsequently, a constant current discharge was performed up to 2.2 V with a current value of 120 C to obtain a discharge curve (time-voltage), and the low temperature internal resistance Rc was calculated by the internal resistance calculation method.
The ratio Rc / Ra of the internal resistance Rc at −30 ° C. and the internal resistance Ra at 25 ° C. was 13.1.

[Gas generation amount after high temperature storage test]
The power storage element obtained in the above step reaches 4.0 V at a current value of 100 C using a charging / discharging device (5V, 360A) manufactured by Fujitsu Telecom Networks Limited in a constant temperature bath set at 25 ° C. It was charged with a constant current until it was charged, and then a constant voltage charge of applying a constant voltage of 4.0 V was performed for a total of 10 minutes. Then, the cell was stored in a 60 ° C environment, taken out from the 60 ° C environment every two weeks, charged to 4.0 V in the cell voltage in the same charging step, and then the cell was stored again in the 60 ° C environment. .. This step was repeated for 3 months, and the cell volume Va before the start of the storage test and the cell volume Vb 3 months after the storage test were measured by the Archimedes method. The amount of gas generated by Vb-Va was 22.1 × 10 ^-3 cc / F.

[Calculation of Rb / Ra]
For the power storage element after the high temperature storage test, the room temperature internal resistance Rb after the high temperature storage test was calculated in the same manner as in the above [Calculation of Ra and F].
The ratio Rb / Ra calculated by dividing this Rb (Ω) by the internal resistance Ra (Ω) before the high temperature storage test obtained in the above [Calculation of Ra / F] was 1.18.
[Calculation of Fb / Fa]
For the power storage element after the high temperature storage test, the capacitance Fb after the high temperature storage test was calculated in the same manner as in the above [Calculation of energy density].
The ratio Fb / Fa calculated by dividing this Fb (Ω) by the capacitance Fa (Ω) before the high temperature storage test obtained in the above [Calculation of Ra / F] was 0.76.

(Examples 2 to 34 and Comparative Examples 1 to 5)
In Example 1, a non-aqueous lithium storage element was produced in the same manner as in Example 1 except that the additives in the negative electrode, the positive electrode precursor, and the non-aqueous electrolyte solution were as shown in Tables 1 and 3, respectively. , Various evaluations were performed. The evaluation results are shown in Tables 2 and 4.

(Example 35)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the lithium-doped step described below, and various evaluations were performed. The evaluation results are shown in Table 2.
<Lithium dope process>
For the obtained non-aqueous lithium type power storage element, use a charging / discharging device (TOSCAT-3100U) manufactured by Toyo System Co., Ltd. under a 25 ° C environment, with a current value of 0.7 A, until the voltage reaches 4.7 V. After the current charge, the initial charge was continuously performed by a method of continuing 4.7 V constant voltage charge for 10 hours, and the negative electrode was lithium-doped.

(Example 36)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the lithium-doped step described below, and various evaluations were performed. The evaluation results are shown in Table 2.
<Lithium dope process>
For the obtained non-aqueous lithium type power storage element, use a charging / discharging device (TOSCAT-3100U) manufactured by Toyo Systems Co., Ltd. under a 25 ° C environment and a current value of 0.7 A until the voltage reaches 4.5 V. After the current charge, the initial charge was performed by the method of continuing the 4.5 V constant voltage charge for 10 hours, and the negative electrode was lithium-doped.

(Example 37)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the lithium-doped step described below, and various evaluations were performed. The evaluation results are shown in Table 2.
<Lithium dope process>
For the obtained non-aqueous lithium type power storage element, use a charging / discharging device (TOSCAT-3100U) manufactured by Toyo System Co., Ltd. under a 25 ° C environment and a current value of 0.7 A until the voltage reaches 4.3 V. After the current charge, the initial charge was continuously carried out by a method of continuing the 4.3 V constant voltage charge for 10 hours, and the negative electrode was lithium-doped.

(Comparative Example 6)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the lithium-doped step described below, and various evaluations were performed. The evaluation results are shown in Table 4.
<Lithium dope process>
For the obtained non-aqueous lithium type power storage element, use a charging / discharging device (TOSCAT-3100U) manufactured by Toyo System Co., Ltd. under a 25 ° C environment and a current value of 0.7 A until the voltage reaches 4.9 V. After the current charge, the initial charge was continuously performed by the method of continuing the 4.9 V constant voltage charge for 10 hours, and the negative electrode was lithium-doped.

(Comparative Example 7)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the lithium-doped step described below, and various evaluations were performed. The evaluation results are shown in Table 4.
<Lithium dope process>
For the obtained non-aqueous lithium type power storage element, use a charging / discharging device (TOSCAT-3100U) manufactured by Toyo Systems Co., Ltd. under a 25 ° C environment and a current value of 0.7 A until the voltage reaches 4.1 V. After the current charge, the initial charge was continuously carried out by a method of continuing 4.1 V constant voltage charge for 10 hours, and the negative electrode was lithium-doped.

(Example 38)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the aging step described below, and various evaluations were performed. The evaluation results are shown in Table 2.
<Aging process>
The non-aqueous lithium-type power storage element after lithium doping is subjected to constant current discharge at 0.7 A until the voltage reaches 3.0 V, and then constant current constant voltage charge up to 4.2 V for 1 hour. The voltage was adjusted to 4.2V. Subsequently, the non-aqueous lithium-type power storage element was stored in a constant temperature bath at 60 ° C. for 20 hours.

(Example 39)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the aging step described below, and various evaluations were performed. The evaluation results are shown in Table 2.
<Aging process>
The non-aqueous lithium-type power storage element after lithium doping is subjected to constant current discharge at 0.7 A until the voltage reaches 3.0 V, and then constant current constant voltage charge up to 3.6 V for 1 hour. The voltage was adjusted to 3.6V. Subsequently, the non-aqueous lithium-type power storage element was stored in a constant temperature bath at 60 ° C. for 20 hours.

(Comparative Example 8)
A non-aqueous lithium storage element was produced in the same manner as in Example 1 except that the aging step was eliminated, and various evaluations were performed. The evaluation results are shown in Table 4.
(Comparative Example 9)
A non-aqueous lithium-type power storage device was produced in the same manner as in Example 1 except for the aging step described below, and various evaluations were performed. The evaluation results are shown in Table 4.
<Aging process>
The non-aqueous lithium-type power storage element after lithium doping is subjected to constant current discharge at 0.7 A until the voltage reaches 3.0 V, and then constant current constant voltage charge up to 4.4 V for 1 hour. The voltage was adjusted to 4.4V. Subsequently, the non-aqueous lithium-type power storage element was stored in a constant temperature bath at 60 ° C. for 20 hours.

(Example 40)
[Preparation of positive electrode precursor D containing transition metal oxide]
A positive electrode precursor D was prepared in the same manner as the positive electrode precursor C except that LiNi _0.80 Co _0.15 Al _0.05 O ₂ having an average particle diameter of 4.0 μm was used as the lithium transition metal oxide. , A non-aqueous lithium-type power storage element was produced in the same manner as in Example 1, and various evaluations were performed.
(Example 41)
[Preparation of positive electrode precursor E containing transition metal oxide]
A positive electrode precursor E was prepared in the same manner as the positive electrode precursor C except that LiNi _0.33 Co _0.33 Mn _0.33 O ₂ having an average particle diameter of 3.0 μm was used as the lithium transition metal oxide. , A non-aqueous lithium-type power storage element was produced in the same manner as in Example 1, and various evaluations were performed.

(Examples 42 to 51)
In the manufacturing process of the positive electrode precursor A, the non-aqueous lithium type is the same as in Example 1 except that the primary drying step, the pressing step, and the secondary drying step after coating are as shown in Table 5, respectively. A power storage element was manufactured and various evaluations were performed. The evaluation results are shown in Table 6.

(Comparative Example 10)
<Manufacturing of positive electrode precursor F>
The activated carbon A obtained above was used as a positive electrode active material to produce a positive electrode precursor.
87.5 parts by mass of activated carbon A, 3.0 parts by mass of KB (Ketchen Black), 1.5 parts by mass of PVP (polyvinylpyrrolidone), 8.0 parts by mass of PVDF (polyvinylidene fluoride), and NMP. (N-Methylpyrrolidone) was mixed, and the mixture was dispersed using a thin film swirl type high-speed mixer fill mix manufactured by PRIMIX under the condition of a peripheral speed of 15 m / s to obtain a coating liquid. The viscosity (ηb) and TI value of the obtained coating liquid were measured using an E-type viscometer TVE-35H manufactured by Toki Sangyo Co., Ltd. As a result, the viscosity (ηb) was 2,500 mPa · s, and the TI value was 4.5. In addition, the degree of dispersion of the obtained coating liquid was measured using a grain gauge manufactured by Yoshimitsu Seiki Co., Ltd. As a result, the particle size was 35 μm. The above coating liquid is applied to one or both sides of a 15 μm thick aluminum foil using a die coater manufactured by Toray Engineering Co., Ltd. under a coating speed of 1 m / s, dried at a drying temperature of 100 ° C., and a positive electrode precursor. Got The obtained positive electrode precursor was pressed using a roll press machine under the conditions of a pressure of 4 kN / cm and a surface temperature of the pressed portion of 25 ° C. The average thickness of the positive electrode active material layer of the positive electrode precursor obtained above was measured at any 10 points of the positive electrode precursor using a film thickness meter Linear Gauge Sensor GS-551 manufactured by Ono Keiki Co., Ltd. It was calculated by subtracting the thickness of the aluminum foil from the value. As a result, the film thickness of the positive electrode active material layer was 110 μm per one side. As a result of calculating the basis weight by the above method, the basis weight of the positive electrode active material layer was 52 g · m ^-2 per one side.

<Manufacturing of negative electrode D>
In the production of the negative electrode A, the negative electrode D was manufactured by the same method except that the negative electrode current collector was a copper foil having a through hole with a thickness of 15 μm. As a result, the film thickness of the negative electrode active material layer of the negative electrode C was 40 μm per one side.
<Manufacturing of negative electrode E>
In the production of the negative electrode C, the negative electrode E was manufactured by the same method except that the negative electrode current collector was a copper foil having a through hole with a thickness of 15 μm. As a result, the film thickness of the negative electrode active material layer of the negative electrode D was 25 μm per one side.
<Assembly of power storage element>
The double-sided negative electrode D and the double-sided positive electrode precursor were cut into 10 cm × 10 cm (100 cm ² ). A lithium metal foil corresponding to 380 mAh / g per unit mass of the negative electrode active material A was attached to one side of the double-sided negative electrode D. A single-sided positive electrode precursor is used for the uppermost surface and the lowermost surface, and 21 double-sided negative electrodes and 20 double-sided positive electrode precursors that have undergone the lithium pasting step are used. Laminated with a porous membrane separator sandwiched between them. Then, the negative electrode terminal and the positive electrode terminal were connected to the negative electrode and the positive electrode precursor by ultrasonic welding, respectively, to form an electrode laminate. This electrode laminate was vacuum dried at 80 ° C. and 50 Pa for 60 hr. This electrode laminate is inserted into an exterior body made of a laminated film under a dry environment with a dew point of −45 ° C., and the three outer bodies of the electrode terminal portion and the bottom portion are heat-sealed at 180 ° C., 20 sec, and 1.0 MPa. did. A non-aqueous lithium-type power storage element was assembled by injecting a non-aqueous electrolyte solution and sealing the exterior body.

<Lithium dope process>
The obtained non-aqueous lithium-type power storage element was left to stand for 21 hours in a constant temperature bath set at 45 ° C. to perform lithium doping on the negative electrode.
<Aging process>
The lithium-doped non-aqueous lithium-type power storage device was adjusted to a cell voltage of 3.0 V, and then stored in a constant temperature bath set at 45 ° C. for 24 hours. Subsequently, using a charging / discharging device manufactured by Asuka Electronics, the charging current is 10A and the discharging current is 10A, and a constant current charging and a constant current discharging charging / discharging cycle are performed between the lower limit voltage of 2.0 V and the upper limit voltage of 4.0 V. Repeated times.
A non-aqueous lithium-type storage element was produced in the same manner as in Example 1 except that the method described above was used for the storage element assembly, the lithium doping process, and the aging process, and various evaluations were performed. The evaluation results are shown in Table 4.

<Comparative Examples 11 to 13>
In Comparative Example 15, a non-aqueous lithium-type power storage element was produced in the same manner as in Comparative Example 10, except that the negative electrode, the positive electrode precursor, and the additives in the non-aqueous electrolyte solution were each as shown in Table 3. Was evaluated. The evaluation results are shown in Table 4.

The abbreviations for additives in Table 1 or 3 have the following meanings, respectively.
[Additive]
ESF: Ethylene sultone PSF: 1,2-propylene sultone TP: Thiophene SFL: 3-Sulfolene PS: 1,3-Propane sultone PES: 1-Propene 1,3-Sultone TEP: Triethyl phosphate TMSP: Tris oxyphosphate (Trimethylsilyl)
TTPE: 1,1,2,2 tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether TFEE: 2,2,2-trifluoroethyl ether

In the non-aqueous lithium storage element of the present invention, a plurality of non-aqueous lithium storage elements can be connected in series or in parallel to form a storage module. The non-aqueous lithium power storage element and the power storage module of the present invention are a power regeneration system of a hybrid drive system of an automobile, which is required to have high load charge / discharge cycle characteristics, a natural power generation such as solar power generation or wind power generation, or a power load in a microgrid or the like. Leveling system, non-disruptive power supply system in factory production equipment, non-contact power supply system for leveling voltage fluctuations such as microwave transmission or electrolytic resonance and storage of energy, utilization of power generated by vibration power generation, etc. It can be suitably used for an energy harvest system for the purpose of.
The non-aqueous lithium storage element of the present invention is preferable because the effect of the present invention is maximized when applied as a lithium ion capacitor or a lithium ion secondary battery.

Claims (55)

A non-aqueous lithium storage element including an electrode laminate having a negative electrode, a positive electrode and a separator, a non-aqueous electrolyte solution, and an exterior body accommodating the electrode laminate and the non-aqueous electrolyte solution.
The negative electrode has a negative electrode current collector and a negative electrode active material layer containing a negative electrode active material provided on one side or both sides of the negative electrode current collector, and the negative electrode active material stores lithium ions. Contains carbon material that can be released
The positive electrode has a positive electrode current collector and a positive electrode active material layer containing a positive electrode active material provided on one side or both sides of the positive electrode current collector, and the positive electrode active material contains activated carbon.
The negative electrode active material layer and the positive electrode active material layer have the following formula (1):

{In the formula, X ¹ is hydrogen, lithium, an alkyl group having 1 to 6 carbon atoms, a mono or polyhydroxyalkyl group having 1 to 6 carbon atoms or a lithium alkoxide thereof, an alkenyl group having 2 to 6 carbon atoms, and 2 carbon atoms. A mono or polyhydroxyalkenyl group of ~ 6 or a lithium alkoxide thereof, a cycloalkyl group or an aryl group having 3 to 6 carbon atoms, and X ² is a hydrogen, lithium, or an alkyl group having 1 to 12 carbon atoms. .. }
Contains sulfur compounds represented by
The total amount of the sulfur compound represented by the above formula (1) contained in the positive electrode active material layer is 0.10 × 10 ^-5 mol / g to 50 × 10 ^-5 mol / g per unit mass of the positive electrode active material layer. g,
The total amount of the sulfur compound represented by the above formula (1) contained in the negative electrode active material layer is 0.10 × 10 ^-5 mol / g to 40 × 10 ^-5 mol / g per unit mass of the negative electrode active material layer. g, and the content per unit mass of the positive electrode active material layer is A,
The content of the negative electrode active material layer per unit mass is B,
A non-aqueous lithium-type power storage element having 0.50 ≦ A / B ≦ 12. The non-aqueous electrolyte solution has the following formula (1-1):

{In the formula, R ⁵ to R ⁸ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
The non-aqueous lithium-type power storage element according to claim 1, which contains the cyclic sulfuric acid compound represented by 1 in 0.1% by mass to 5% by mass based on the total amount of the non-aqueous electrolyte solution. The non-aqueous electrolyte solution has the following formula (1-2):

{In the formula, R ¹ to R ⁴ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , And at least one selected from the group consisting of alkyl esters having 1 to 6 carbon atoms. }
Thiophene compound represented by;
The following formula (1-3):

{In the formula, R ⁹ to R ¹⁴ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Sultone compound represented by;
The following formula (1-4):

{In the formula, R ¹⁵ to R ²⁰ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Sultone compound represented by;
The following formula (1-5):

{In the formula, R ²¹ to R ²⁶ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different. }
The compound represented by; and the following formula (1-6):

{In the formula, R ²⁷ to R ³⁰ represent at least one selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, and an alkyl halide group having 1 to 12 carbon atoms, and each other. It may be the same or different; and n is an integer from 0 to 3. }
Claim 1 or 2 containing at least one sulfur-containing compound selected from the group consisting of the cyclic sulfite compound represented by the above in an amount of 0.1% by mass to 5% by mass based on the total amount of the non-aqueous electrolyte solution. The non-aqueous lithium-type power storage element described in 1. The non-one of claims 1 to 3, wherein the cyclic sulfuric acid compound represented by the formula (1-1) is ethylene sulfate, 1,2-propylene sulfate, or trimethylene sulfate. Aqueous lithium-type power storage element. The thiophene compound represented by the above formula (1-2) is thiophene, 2-methylthiophene, 3-methylthiophene, 2-cyanothiophene, 3-cyanothiophene, 2,5-dimethylthiophene, 2-methoxythiophene, 3 -Methoxythiophene, 2-chlorothiophene, 3-chlorothiophene, 2-acetylthiophene or 3-acetylthiophene,
The sultone compound represented by the above formula (1-3) is 1,3-propane sultone, 2,4-butane sultone, 1,4-butane sultone, 1,3-butane sultone or 2,4-pentane sultone.
The sultone compound represented by the above formula (1-4) is 1,3-propene sultone or 1,4-butene sultone.
The compound represented by the formula (1-5) is 3-sulfolene, and the cyclic sulfite compound represented by the formula (1-6) is ethylene sulfite, 1,2-propylene sulfite or 1,3. -The non-aqueous lithium-type power storage element according to claim 3, which is propylene sulfite. The non-aqueous electrolyte solution has the following formula (2):

{In the formula, X ¹ to X ³ are independently hydrogen atom, halogen atom, formyl group, acetyl group, nitrile group, acetyl group, alkyl group having 1 to 6 carbon atoms, and alkoxy group having 1 to 6 carbon atoms. , An alkyl ester having 1 to 6 carbon atoms, or -Si (R ¹ ) ₃ (in the formula, R ¹ represents an alkyl group having 1 to 6 carbon atoms), and at least one of X ¹ to X ³ . Is not a hydrogen atom. }
The non-aqueous lithium-type storage storage according to any one of claims 1 to 5, which contains 0.1% by mass to 3% by mass of the phosphoric acid ester compound represented by element. The sixth aspect of claim 6, wherein the phosphoric acid ester compound represented by the formula (2) is trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris phosphate (trimethylsilyl), tritryl phosphate, triphenyl phosphate, or dioctyl phosphate. Non-aqueous lithium-type power storage element. The following formula (3):
R ³¹ -OR ³² (3)
{In the formula, R ³¹ is a halogen atom or a halogenated alkyl group having 1 to 12 carbon atoms, and R ³² is a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, or 1 to 12 carbon atoms. Halogen alkyl group. }
The non-aqueous lithium according to any one of claims 1 to 7, wherein the acyclic halogen-containing ether represented by 1 is contained in an amount of 0.1% by mass to 3% by mass based on the total amount of the non-aqueous electrolytic solution. Type storage element. The acyclic halogen-containing ether represented by the above formula (3) is C ₂ F ₅ OC ₂ F ₅ , C ₃ F ₇ OC ₃ F ₇ , C ₄ F ₉ OC ₄ F ₉ , C ₆ F ₁₃ OC ₆ F. ₁₃ , C ₂ F ₅ OCH ₃ , C ₃ F ₇ OCH ₃ , C ₄ F ₉ OCH ₃ , C ₆ F ₁₃ OCH ₃ , C ₂ F ₅ OCH ₅ , C ₃ F ₇ OCH ₅ , C ₄ F ₉ OC ₂ H ₅ , C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ , CF ₃ CH ₂ OCF ₂ CF ₂ H, CHF ₂ CF ₂ OCH ₂ CF ₃ , CHF ₂ CF ₂ CH ₂ OCF ₂ CF ₂ H, CF _{3 25 . _ _ _ _ _ _ _ _ _ _ _} The non-aqueous lithium-type power storage element described. The non-aqueous lithium storage element according to any one of claims 1 to 9, wherein the non-aqueous electrolyte solution contains at least one of LiPF ₆ , LiClO ₄ , and LiBF ₄ . Any of claims 1 to 10, wherein the concentration of LiN (SO ₂ F) ₂ in the non-aqueous electrolyte solution is 0.1 mol / L or more and 1.5 mol / L or less based on the total amount of the non-aqueous electrolyte solution. The non-aqueous lithium-type power storage element according to item 1. The non-aqueous electrolyte solution contains dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC), and the volume ratio (DMC / EMC) of the dimethyl carbonate to the ethyl methyl carbonate is 0.5 or more and 8.0 or less. The non-aqueous lithium-type power storage element according to any one of claims 1 to 11. The positive electrode contains an alkali metal carbonate, and the alkali metal carbonate is at least one selected from the group consisting of lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate, and the positive electrode active material. The non-aqueous lithium power storage element according to any one of claims 1 to 12, wherein the content of the alkali metal carbonate with respect to the total amount is 1% by mass or more and 50% by mass or less. The non-aqueous lithium-type power storage element according to any one of claims 1 to 13, wherein the positive electrode current collector and the negative electrode current collector are non-porous metal foils. The non-aqueous lithium-type power storage element according to any one of claims 1 to 14, wherein the negative electrode active material is at least two types. The non-aqueous lithium-type power storage according to any one of claims 1 to 15, wherein the negative electrode active material has at least two types, and the average particle size of at least one type of negative electrode active material is 1 μm or more and 15 μm or less. element. The negative electrode contains at least one negative electrode active material A selected from the composite carbon material A containing natural graphite, artificial graphite, low crystalline graphite, soft carbon, hard carbon, or any of them as a base material. It also contains at least one negative electrode active material B selected from the composite carbon material B containing activated carbon, carbon black, template porous carbon, high specific surface graphite, carbon nanoparticles, or any of them as a base material. , The non-aqueous lithium type power storage element according to any one of claims 1 to 16. The non-aqueous lithium according to claim 17, wherein the ratio of the negative electrode active material B is 1.0% by mass to 45.0% by mass based on the total amount of the negative electrode active material contained in the negative electrode active material layer. Type storage element. The BET specific surface area of the negative electrode active material A is 0.5 m ² / g or more and 35 m ² / g or less, and the BET specific surface area of the negative electrode active material B is 50 m ² / g or more and 1,500 m ² / g or less. The non-aqueous lithium power storage element according to claim 17 or 18. The non-aqueous lithium-type power storage element according to any one of claims 17 to 19, wherein the amount of lithium ion doped in the negative electrode active material A is 50 mAh / g or more and 520 mAh / g or less per unit mass. The non-aqueous lithium-type power storage element according to any one of claims 17 to 20, wherein the amount of lithium ions doped in the negative electrode active material B is 530 mAh / g or more and 2,500 mAh / g or less per unit mass. The amount of mesopores derived from pores having a diameter of 20 Å or more and 500 Å or less calculated by the BJH method for the positive electrode active material contained in the positive electrode active material layer is V1 (cc / g), and the diameter is less than 20 Å calculated by the MP method. When the amount of micropores derived from the pores is V2 (cc / g), 0.3 <V1 ≦ 0.8 and 0.5 ≦ V2 ≦ 1.0 are satisfied, and the measurement is performed by the BET method. The non-aqueous lithium-type power storage element according to any one of claims 1 to 21, which is an activated carbon having a specific surface area of 1,500 m ² / g or more and 3,000 m ² / g or less. The positive electrode active material contained in the positive electrode active material layer has a mesopore amount V1 (cc / g) of 0.8 <V1 ≦ 2.5 derived from pores having a diameter of 20 Å or more and 500 Å or less calculated by the BJH method. The micropore amount V2 (cc / g) derived from the pores having a diameter of less than 20 Å calculated by the MP method satisfies 0.8 <V2 ≦ 3.0, and the specific surface area measured by the BET method is 2. The non-aqueous lithium power storage element according to any one of claims 1 to 21, which is an activated carbon exhibiting 300 m ² / g or more and 4,000 m ² / g or less. The non-aqueous lithium-type power storage element according to any one of claims 1 to 23, wherein the positive electrode active material contains a transition metal oxide capable of storing and releasing lithium ions. The non-aqueous lithium power storage element according to claim 24, wherein the transition metal oxide is a lithium metal composite oxide having a layered structure, an olivine structure, or a spinel structure. The transition metal oxide
Li _x1 CoO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 NiO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 Ny M ¹ (1- _{y )} O ₂ (In the formula, M ¹ is at least one element selected from the group consisting of Co, Mn, Al, Fe, Mg, and Ti, and x1 is 0. ≦ x1 ≦ 2 and y satisfies 0.2 <y <0.97),.
Li _x1 Ni _1/3 Co _1/3 Mn _1/3 O ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 MnO ₂ (in the formula, x1 satisfies 0≤x1≤2),
α-Li _x1 FeO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 VO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 CrO ₂ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 Mn ₂ O ₄ (in the formula, x1 satisfies 0≤x1≤2),
Li _x1 M ² _y Mn _(2-y) O ₄ (M ² is at least one element selected from the group consisting of Co, Ni, Al, Fe, Mg, and Ti, and x1 is 0 ≦ x 1 ≦. 2 and y satisfies 0.2 <y <0.97),
Li _x1 Ni _a Co _b Al _(1-ab) O ₂ (In the formula, x1 satisfies 0≤x1≤2, and a and b are 0.2 <a <0.97, 0., respectively. 2 <b <0.97),
Li _x1 Ni _c Cod Mn _{(1-c-d) O 2} (In the formula, x1 satisfies 0≤x1≤2, and c and d are 0.2 <c <0.97, 0., respectively. 2 <d <0.97),
Li _x1 M ³ PO ₄ (In the formula, M ³ is at least one element selected from the group consisting of Co, Ni, Fe, Mn, and Cu, and x1 satisfies 0≤x1≤2.) 24 or 25, wherein the lithium metal composite oxide is selected from the group consisting of Li _z V ₂ (PO ₄ ) ₃ (where z satisfies 0 ≦ z ≦ 3). Non-aqueous lithium-type power storage element. The transition metal oxide is Li _x2 FePO ₄ (where x2 satisfies 0≤x1≤2), Li _x2 CoPO ₄ (in the equation, x2 satisfies 0≤x1≤2), and. 24. The aspect of any one of claims 24 to 26, which comprises at least one lithium metal composite oxide selected from the group consisting of Li _x2 MnPO ₄ (where x2 satisfies 0≤x1≤2). Non-aqueous lithium type power storage element. The non-aqueous system according to any one of claims 24 to 27, wherein the activated carbon has an average particle size of 2 μm or more and 20 μm or less, and the transition metal oxide has an average particle size of 0.1 μm or more and 20 μm or less. Lithium-type power storage element. The non-one of claims 24 to 28, wherein the content of the transition metal oxide is 1.0% by mass to 50.0% by mass based on the total weight of the positive electrode active material layer. Aqueous lithium-type power storage element. The initial internal resistance at a cell voltage of 4.2 V is Ra (Ω), the capacitance is F (F), the amount of power is E (Wh), and the volume of the exterior body containing the electrode laminate is V. (L), where the internal resistance at an ambient temperature of −30 ° C. is Rc, the following requirements (a), (b) and (c):
(A) The product Ra / F of Ra and F is 0.5 or more and 3.5 or less;
(B) E / V is 20 or more and 80 or less; and (c) Rc / Ra is 30 or less;
The non-aqueous lithium-type power storage element according to any one of claims 1 to 29, which simultaneously satisfies the above conditions. The initial internal resistance at a cell voltage of 4.2 V is Ra (Ω), the capacitance is Fa (F), the cell voltage is 4.2 V, and the internal resistance at 25 ° C after storage at an ambient temperature of 60 ° C for 2 months. When Rb (Ω) and capacitance are Fb (F), the following requirements (d), (e) and (f) are:
(D) Rb / Ra is 0.8 or more and 3.0 or less;
(E) Fb / Fa is 0.5 or more and 1.2 or less; and (f) The amount of gas generated when stored for 2 months at a cell voltage of 4.2 V and an environmental temperature of 60 ° C. is 30 × at 25 ° C. 10 ^-3 cc / F or less;
The non-aqueous lithium-type power storage element according to any one of claims 1 to 30, which simultaneously satisfies the above conditions. A method for producing a positive electrode precursor, which is a precursor of the positive electrode constituting the non-aqueous lithium-type power storage element according to any one of claims 1 to 31.
The positive electrode precursor has a current collector and a positive electrode active material layer arranged on the current collector.
The positive electrode active material layer contains a positive electrode active material and an alkali metal compound, and contains.
The positive electrode active material contains a carbon material and has the following steps 1), 2), 3), 4) and 5) :.
1) A coating liquid preparation step of kneading the positive electrode active material containing the carbon material with the alkali metal compound to prepare a coating liquid;
2) A coating step of applying the coating liquid to the current collector to prepare a positive electrode precursor;
3) Primary drying step of drying the positive electrode precursor at a temperature of 45 ° C. or higher and 200 ° C. or lower;
4) Pressing step of pressing the positive electrode precursor at a linear pressure of 0.5 kN / cm ² or more and 20 kN / cm ² or less; and 5) Secondary drying of drying the positive electrode precursor at a temperature of 160 ° C. or higher and 250 ° C. or lower. Process;
A method for producing a positive electrode precursor including. The method for producing a positive electrode precursor according to claim 32, wherein the 5) secondary drying step is performed before the 4) pressing step. The method for producing a positive electrode precursor according to claim 32, wherein the integrated drying step of integrating the 3) primary drying step and the 5) secondary drying step is performed before the 4) pressing step. The method for manufacturing a negative electrode constituting the non-aqueous lithium storage element according to any one of claims 1 to 31.
The negative electrode has a current collector and a negative electrode active material layer arranged on the current collector.
The following steps 1), 2), 3), 4) and 5):
1) A coating liquid preparation step of kneading a negative electrode active material containing a carbon material and an alkali metal compound to prepare a coating liquid;
2) A coating step of applying the coating liquid to the current collector to prepare a negative electrode;
3) Primary drying step of drying the negative electrode at a temperature of 45 ° C. or higher and 200 ° C. or lower;
4) Pressing step of pressing the negative electrode with a linear pressure of 0.5 kN / cm ² or more and 20 kN / cm ² or less; and 5) Secondary drying step of drying the negative electrode at a temperature of 160 ° C. or more and 250 ° C. or less;
A method for manufacturing a negative electrode including. The method for manufacturing a negative electrode according to claim 35, wherein the 5) secondary drying step is performed before the 4) pressing step. The method for manufacturing a negative electrode according to claim 35, wherein the integrated drying step of integrating the 3) primary drying step and the 5) secondary drying step is performed before the 4) pressing step. A power storage module including the non-aqueous lithium power storage element according to any one of claims 1 to 31. A power regeneration assist system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. A power load leveling system including the non-aqueous lithium storage element according to any one of claims 1 to 31. An uninterruptible power supply system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. A non-contact power feeding system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. An energy harvesting system including the non-aqueous lithium storage element according to any one of claims 1 to 31. A power storage system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. A power storage system in which a non-aqueous lithium power storage element according to any one of claims 1 to 31 and a lead battery, a nickel hydrogen battery, a lithium ion secondary battery, or a fuel cell are connected in series or in parallel. A photovoltaic power generation power storage system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. An electric power steering system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. An emergency power supply system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. An in-wheel motor system including the non-aqueous lithium storage element according to any one of claims 1 to 31. An idling stop system including the non-aqueous lithium power storage element according to any one of claims 1 to 31. A vehicle including the non-aqueous lithium-type power storage element according to any one of claims 1 to 31. The vehicle according to claim 51, which is an electric vehicle, a plug-in hybrid vehicle, a hybrid vehicle, or an electric motor vehicle. A quick charging system including the non-aqueous lithium storage element according to any one of claims 1 to 31. A smart grid system including the non-aqueous lithium-type power storage element according to any one of claims 1 to 31. A hybrid excavator including the non-aqueous lithium storage element according to any one of claims 1 to 31.