JP7116311B2 - Electrolyte for non-aqueous electrolyte battery and non-aqueous electrolyte battery using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrolyte for non-aqueous electrolyte batteries and a non-aqueous electrolyte battery using the same.

In recent years, batteries, which are electrochemical devices, have been used in information-related equipment, communication equipment, namely personal computers, video cameras, digital cameras, mobile phones, smart phones, etc. Compact, high energy density power storage systems, electric vehicles, hybrid vehicles , auxiliary power sources for fuel cell vehicles, power storage, and other large-scale power storage systems are attracting attention. One of the candidates is a non-aqueous electrolyte secondary battery such as a lithium ion battery, which has a high energy density and voltage and a high capacity, and is currently being actively researched and developed.

The electrolyte for non-aqueous electrolyte batteries (hereinafter sometimes referred to as "non-aqueous electrolyte") is lithium hexafluorophosphate (hereinafter LiPF ₆ ), bis(fluorosulfonylimide)lithium (hereinafter LiFSI), lithium tetrafluoroborate (hereinafter LiBF ₄ ), and other non-aqueous electrolytes in which fluorine-containing electrolytes are dissolved are used to obtain high-voltage and high-capacity batteries. It is widely used because it is convenient. However, non-aqueous electrolyte batteries using such a non-aqueous electrolyte are not necessarily satisfactory in terms of battery characteristics such as cycle characteristics and output characteristics.

For example, in the case of a lithium ion secondary battery, when lithium cations are inserted into the negative electrode during initial charging, the negative electrode and lithium cations, or the negative electrode and the electrolyte solvent react, and lithium oxide, lithium carbonate, and alkyl carbonate are formed on the surface of the negative electrode. Forms a coating mainly composed of lithium. This film on the surface of the electrode is called Solid Electrolyte Interface (SEI), and its properties greatly affect battery performance, such as suppressing further reductive decomposition of the solvent and suppressing deterioration of battery performance. In addition, it is also known that a film of decomposition products is formed on the surface of the positive electrode, which also plays an important role in suppressing oxidative decomposition of the solvent and suppressing gas generation inside the battery.

It is important to form a stable SEI with high ionic conductivity and low electronic conductivity in order to improve durability such as cycle and high temperature storage and battery characteristics such as input and output characteristics. Attempts have been made to positively form a good SEI by adding a small amount (usually 0.001% by mass or more and 10% by mass or less) of a compound called an additive to the electrolytic solution.

For example, in Patent Document 1, vinylene carbonate (hereinafter referred to as VC) is used as an additive that forms an effective SEI that significantly improves battery durability. In addition to VC, by using a silicon compound having an unsaturated bond in Patent Documents 2 and 3, or by using a silicon compound containing both an unsaturated bond and a halogen in Patent Document 4, cycle characteristics and low-temperature characteristics are improved. It is disclosed that a battery having excellent efficiencies can be obtained. Further, Patent Document 5 discloses that the use of trialkoxyvinylsilane has the effect of suppressing battery swelling in a lithium secondary battery with a voltage of 4.2 V or more and less than 4.35 V. Furthermore, by using a silicon compound having an unsaturated bond and a fluorine-containing compound (fluorophosphate with a specific structure, imide salt with a fluorophosphoryl structure and/or fluorosulfonyl structure with a specific structure) at the same time, -30 Patent Document 6 discloses that a battery having excellent low-temperature output characteristics even at temperatures below 50° C. and excellent cycle characteristics at high temperatures of 50° C. or higher can be obtained.

In addition to research on improving battery characteristics such as cycle characteristics and output characteristics, research to increase the energy density of the battery itself is being actively pursued. This is a method of increasing the charging voltage of the battery, which increases the average discharge voltage and provides a large discharge capacity. However, as the voltage rises, the solvent is oxidized and decomposed, and the expansion of the battery due to the generation of gas is remarkable. At present, high-voltage batteries with a charging voltage of 4.5 V or more have not been widely put into practical use.

Another method of increasing the energy density of batteries is to use nickel oxide as the positive electrode. For example, Patent Document 7 discloses a lithium ion secondary battery using LiNiO ₂ as a positive electrode.
Although nickel oxide has a high theoretical capacity, it has low thermal stability during charging. At first, cobalt oxide, manganese oxide, iron phosphate, and the like were mainly used as positive electrode active materials. However, the demand for improving the energy density of batteries has become more stringent, and cobalt is a concern about the reserves of natural resources. has come into use. For example, Patent Document 8 discloses a positive electrode in which part of nickel is replaced with manganese, cobalt, or the like.
Regarding this ternary positive electrode, in order to further reduce the use of cobalt and to further increase the positive electrode capacity, the development of batteries using a positive electrode with a nickel ratio further increased has been very active. It is Here, Ni-rich positive electrodes with an increased nickel ratio include nickel-, cobalt-, and manganese-based ones with a ratio of "3:1:1" or "8:1:1", and manganese replaced with aluminum. , the ratio of nickel, cobalt and aluminum is "8.5 to 1.0 to 0.5", "8.8 to 0.9 to 0.3", "9.0 to 0.5 to 0.5", etc. are known.
An example of a method for synthesizing the LiPF ₆ concentrate used in the electrolyte for non-aqueous electrolyte batteries is disclosed in Patent Document 9, for example.

JP-A-8-045545 Japanese Patent No. 3497812 Japanese Patent No. 5072379 Japanese Patent Application Laid-Open No. 2004-039510 Japanese Patent No. 6051537 JP 2016-157679 A JP-A-6-096769 WO2010/113583 Japanese Patent No. 5845955 Patent No. 5668684 publication

Z. Anorg. Chem. 2006, 632, P1356 (Rovnanik, Prvel, "Syntheses of Phosphoryl Chloro- and Bromofluorides and Crystal Structures of POFCl2 and POF2Cl, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim")

Electrolytes containing silicon compounds with unsaturated bonds are certainly excellent in terms of durability (cycle characteristics, high-temperature storage characteristics), but Ni-rich positive electrodes (specifically, Ni content of 30 to 100% by mass) tended to elute from the positive electrode into the electrolyte when charging and discharging were repeated. The eluted Ni deposits on the negative electrode, which can cause a short circuit in the battery and is a very dangerous situation.

The present invention provides an electrolytic solution containing a silicon compound having an unsaturated bond in which the elution of Ni from a Ni-rich positive electrode into the electrolytic solution is reduced without impairing the capacity retention rate after cycling, and the electrolytic solution. An object of the present invention is to provide a non-aqueous electrolyte battery having a positive electrode with a high Ni content.

The present invention
An electrolytic solution for a non-aqueous electrolyte battery comprising a positive electrode containing at least one oxide containing at least nickel as a positive electrode active material, wherein the nickel content in the metal contained in the positive electrode active material is 30 to 100% by mass. and
(I) a non-aqueous organic solvent,
(II) a solute that is an ionic salt;
(III) at least one selected from the group consisting of compounds represented by general formula (1), and
(IV) Lithium fluorosulfonate (hereinafter sometimes referred to as LiSO ₃ F), a compound having an O=SF bond represented by general formula (2), and O=P represented by general formula (3) At least one selected from the group consisting of a compound having a -F bond, a compound having a P( ₌ O)F2 bond represented by general formula (4), and a compound represented by general formula (5),
Electrolyte for non-aqueous electrolyte batteries (hereinafter simply referred to as "non-aqueous It may be described as "electrolyte" or "electrolyte").

Si(R ¹ ) _a (R ² ) _4-a (1)
[In general formula (1), each R ¹ independently represents a group having a carbon-carbon unsaturated bond.
R ² each independently represents a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an allyl group having 3 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. an aryl group having 6 to 15 carbon atoms, an allyloxy group having 3 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, and an aryloxy group having 6 to 15 carbon atoms. group, and these groups may have a fluorine atom and/or an oxygen atom. The phrase "having a fluorine atom" specifically refers to the above group in which a hydrogen atom is substituted with a fluorine atom. Further, "having an oxygen atom" specifically includes groups in which "--O--" (ether bond) is interposed between the carbon atoms of the above groups.
a is 2-4. ]

R ³ -S(=O) ₂ -F (2)
[In general formula (2), R ³ is an alkyl group, an alkenyl group, an aryl group, an alkoxy group, or an aryloxy group. ]
of R ³ above,
The alkyl group is preferably a methyl group, a trifluoromethyl group, an ethyl group, a pentafluoroethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group,
The alkenyl group is preferably an ethenyl group,
The aryl group is a phenyl group, a methylphenyl group, a dimethylphenyl group, a tert-butylphenyl group, a tert-amylphenyl group, a biphenyl group, or a naphthyl group (even if a hydrogen atom in each aromatic ring is substituted with a fluorine atom). good) is preferred,
The aryloxy group is a phenoxy group, a methylphenoxy group, a dimethylphenoxy group, a tert-butylphenoxy group, a tert-amylphenoxy group, or a naphthoxy group (a hydrogen atom of each aromatic ring may be substituted with a fluorine atom). is preferred,
The alkoxy group is preferably a cyclohexyloxy group, a methoxy group, or an ethoxy group, which may be substituted with fluorine.
Among them, R3 is particularly preferably a methyl group ^, a trifluoromethyl group, an ethyl group, an ethenyl group, or a phenyl group from the viewpoint of the balance between the capacity retention rate after cycling and the effect of suppressing Ni elution, and the stability of the compound.

R ⁴ -PF(=O)-R ⁵ (3)
[In general formula (3), R ⁴ is an alkoxy group or an aryloxy group, and R ⁵ is OLi (where O represents oxygen and Li represents lithium). ]
of R ⁴ above,
Alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, 2,2-dimethylpropoxy, 3-methylbutoxy, 1-methylbutoxy, 1 -ethylpropoxy group, 1,1-dimethylpropoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3-tetrafluoropropoxy group, 1,1,1-trifluoroisopropoxy group, 1 , 1,1,3,3,3-hexafluoroisopropoxy group or cyclohexyloxy group is preferred,
The aryloxy group is preferably a phenoxy group, a methylphenoxy group, a dimethylphenoxy group, a fluorophenoxy group, a tert-butylphenoxy group, a tert-amylphenoxy group, a biphenoxy group, or a naphthoxy group, and each aromatic ring hydrogen atom is It may be substituted with a fluorine atom.
Among them, an ethoxy group is particularly preferable as R ⁴ from the viewpoint of the balance between the capacity retention rate after cycles and the effect of suppressing Ni elution and the stability of the compound.

R ⁶ -P(=O)F ₂ (4)
[In general formula (4), R ⁶ is an aryl group, an alkoxy group, or an aryloxy group. ]
of R ⁶ above,
The aryl group is a phenyl group, a methylphenyl group, a dimethylphenyl group, a tert-butylphenyl group, a tert-amylphenyl group, a biphenyl group, or a naphthyl group (even if a hydrogen atom in each aromatic ring is substituted with a fluorine atom). good) is preferred,
Alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert-butoxy, 2,2-dimethylpropoxy, 3-methylbutoxy, 1-methylbutoxy, 1 -ethylpropoxy group, 1,1-dimethylpropoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3-tetrafluoropropoxy group, 1,1,1-trifluoroisopropoxy group, 1 , 1,1,3,3,3-hexafluoroisopropoxy group or cyclohexyloxy group is preferred,
The aryloxy group is a phenoxy group, methylphenoxy group, dimethylphenoxy group, fluorophenoxy group, tert-butylphenoxy group, tert-amylphenoxy group, biphenoxy group, or naphthoxy group (the hydrogen atom of each aromatic ring is a fluorine atom). may be substituted) is preferred.
Among them, a phenyl group and a phenoxy group are particularly preferable as R ⁶ from the viewpoint of the balance between the capacity retention rate after cycling and the effect of suppressing Ni elution and the stability of the compound.

［一般式（５）中、Ｘは酸素原子、又はハロゲン原子に置換されていてもよいメチレン基であり、Ｙはリン原子、又は硫黄原子である。ｎはＹがリン原子の場合は０、硫黄原子の場合は１である。Ｒ^７及びＲ^８はそれぞれ独立で、ハロゲン原子、ハロゲン原子に置換されていてもよい、アルキル基、アルケニル基、又はアリール基である。なお、Ｙが硫黄原子の場合、Ｒ^８は存在しない。］
上記Ｒ^７及びＲ^８の、
ハロゲン原子はフッ素原子が好ましく
ハロゲン原子に置換されていてもよいアルキル基は、メチル基、トリフルオロメチル基、エチル基、ペンタフルオロエチル基、プロピル基、ブチル基、ペンチル基、又はヘキシル基が好ましく、
ハロゲン原子に置換されていてもよいアルケニル基は、エテニル基が好ましく、
ハロゲン原子に置換されていてもよいアリール基は、フェニル基、メチルフェニル基、ジメチルフェニル基、ｔｅｒｔ－ブチルフェニル基、ｔｅｒｔ－アミルフェニル基、ビフェニル基、又はナフチル基（それぞれの芳香環の水素原子がフッ素原子に置換されていても良い）が好ましい。
中でも、サイクル後の容量維持率とＮｉ溶出の抑制効果のバランスや、化合物の安定性の観点から、Ｒ^７、Ｒ^８はフッ素原子、メチル基、トリフルオロメチル基、エチル基、エテニル基、フェニル基、フルオロフェニル基が特に好ましい。

[In general formula (5), X is an oxygen atom or a methylene group optionally substituted with a halogen atom, and Y is a phosphorus atom or a sulfur atom. n is 0 when Y is a phosphorus atom and 1 when Y is a sulfur atom. R ⁷ and R ⁸ are each independently a halogen atom, an alkyl group optionally substituted by a halogen atom, an alkenyl group, or an aryl group. Note that when Y is a sulfur atom, ^R8 does not exist. ]
of R ⁷ and R ⁸ above,
The halogen atom is preferably a fluorine atom, and the alkyl group optionally substituted by a halogen atom is preferably a methyl group, a trifluoromethyl group, an ethyl group, a pentafluoroethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. ,
The alkenyl group optionally substituted by a halogen atom is preferably an ethenyl group,
The aryl group optionally substituted by a halogen atom includes a phenyl group, a methylphenyl group, a dimethylphenyl group, a tert-butylphenyl group, a tert-amylphenyl group, a biphenyl group, or a naphthyl group (the hydrogen atom of each aromatic ring may be substituted with a fluorine atom).
Among them, R ⁷ and R ⁸ are fluorine atom, methyl group, trifluoromethyl group, ethyl group, ethenyl group, phenyl Groups such as the fluorophenyl group are particularly preferred.

It is important that (III) and (IV) are present in the electrolytic solution of the present invention at the above-described predetermined concentrations.
By containing the above (IV),
When the electrolytic solution containing the above (III) is applied to a battery having a Ni-rich positive electrode, elution of Ni from the Ni-rich positive electrode into the electrolytic solution is reduced.

As the component (IV), lithium fluorosulfonate, a compound having an O=S—F bond represented by the general formula ( ₂ ), and a P(=O)F2 bond represented by the general formula (4) It is particularly preferable to use at least one selected from the group consisting of the compound and the compound represented by the general formula (5), since the effect of suppressing the capacity retention rate after cycling and the elution of Ni can be exhibited in a well-balanced manner.

R ¹ above is preferably an ethenyl group.
In addition, the alkyl group for R ² includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, 3-pentyl group, and is preferably selected from tert-pentyl groups,
Alkoxy groups include methoxy, ethoxy, butoxy, tert-butoxy, propoxy, isopropoxy, 2,2,2-trifluoroethoxy, 2,2,3,3-tetrafluoropropoxy, 1 , 1,1-trifluoroisopropoxy group and 1,1,1,3,3,3-hexafluoroisopropoxy group,
The allyl group is preferably a 2-propenyl group,
The alkynyl group is preferably an ethynyl group,
The aryl group is preferably selected from a phenyl group, a methylphenyl group, a tert-butylphenyl group, and a tert-amylphenyl group (hydrogen atoms of each aromatic ring may be substituted with fluorine atoms),
The allyloxy group is preferably a 2-propenyloxy group,
The alkynyloxy group is preferably a propargyloxy group, and the aryloxy group is a phenoxy group, a methylphenoxy group, a tert-butylphenoxy group, and a tert-amylphenoxy group (each of which the hydrogen atom of the aromatic ring is substituted with a fluorine atom). It is preferable to select from ).

Further, it is more preferable that a in the general formula (1) is 3 or 4 from the viewpoint of excellent durability improvement effect.

In addition, the above (III) is preferably at least one selected from the group consisting of compounds (1-1) to (1-28) described later, and among them (1-1), (1 -2), (1-3), (1-4), (1-6), (1-7), (1-8), (1-10), (1-12), (1-15) ), (1-22), (1-23), (1-24), (1-25), (1-26), (1-27), and (1-28). At least one is more preferable from the viewpoint of ease of synthesis and stability of the compound.
Among them, (1-1), (1-2), (1-4), (1-10), (1-12), (1-15), (1-22), (1-24) ), (1-25), and (1-28) are preferably at least one selected from the group consisting of (1-1), (1-2), ( At least one selected from the group consisting of 1-12) and (1-15) is particularly preferred.

According to the present invention, an electrolytic solution containing a silicon compound having an unsaturated bond in which Ni elution from a Ni-rich positive electrode into the electrolytic solution is reduced without impairing the capacity retention rate after cycling, and the electrolytic solution can provide a non-aqueous electrolyte battery comprising a positive electrode with a high Ni content.

Configurations and combinations thereof in the following embodiments are examples, and configuration additions, omissions, substitutions, and other changes are possible without departing from the scope of the present invention. Moreover, the present invention is not limited by the embodiments, but only by the claims.

1. Electrolyte for non-aqueous electrolyte batteries The electrolyte for non-aqueous electrolyte batteries of the present invention is
An electrolytic solution for a non-aqueous electrolyte battery comprising a positive electrode containing at least one oxide containing at least nickel as a positive electrode active material, wherein the nickel content in the metal contained in the positive electrode active material is 30 to 100% by mass. and
(I) a non-aqueous organic solvent,
(II) a solute that is an ionic salt;
(III) at least one selected from the group consisting of compounds represented by the general formula (1); and
(IV) LiSO ₃ F, a compound having an O=SF bond represented by the above general formula (2), a compound having an O=P-F bond represented by the above general formula (3), the above general formula (4) ) and at least one selected from the group consisting of compounds having a P (=O) F ₂ bond represented by the above general formula (5),
The concentration of (IV) is 0.01 to 5.00% by mass with respect to 100% by mass of the total amount of (I) to (IV).

(I) Non-aqueous organic solvent The type of non-aqueous organic solvent used in the electrolyte for non-aqueous electrolyte batteries of the present invention is not particularly limited, and any non-aqueous organic solvent can be used. Specifically, ethyl methyl carbonate (hereinafter referred to as "EMC"), dimethyl carbonate (hereinafter referred to as "DMC"), diethyl carbonate (hereinafter referred to as "DEC"), methyl propyl carbonate, ethyl propyl carbonate, methyl butyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, 2,2,2-trifluoroethyl propyl carbonate, bis(2,2,2-trifluoro ethyl) carbonate, 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, 1,1, 1,3,3,3-hexafluoro-1-propylpropyl carbonate, bis(1,1,1,3,3,3-hexafluoro-1-propyl) carbonate, ethylene carbonate (hereinafter referred to as "EC" ), propylene carbonate (hereinafter referred to as “PC”), butylene carbonate, fluoroethylene carbonate (hereinafter referred to as “FEC”), difluoroethylene carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, 2- methyl fluoropropionate, ethyl 2-fluoropropionate, diethyl ether, dibutyl ether, diisopropyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4- At least one selected from the group consisting of dioxane, N,N-dimethylformamide, acetonitrile, propionitrile, dimethylsulfoxide, sulfolane, γ-butyrolactone, and γ-valerolactone is preferred.

Moreover, it is preferable that the non-aqueous organic solvent is at least one selected from the group consisting of cyclic carbonates and chain carbonates from the viewpoint of excellent cycle characteristics at high temperatures. Moreover, it is preferable that the non-aqueous organic solvent is at least one selected from the group consisting of esters, since the input/output characteristics at low temperatures are excellent.
Specific examples of the cyclic carbonate include EC, PC, butylene carbonate, FEC, etc. Among them, at least one selected from the group consisting of EC, PC, and FEC is preferable.
Specific examples of the chain carbonate include EMC, DMC, DEC, methylpropyl carbonate, ethylpropyl carbonate, 2,2,2-trifluoroethylmethyl carbonate, 2,2,2-trifluoroethylethyl carbonate, 1,1, 1,3,3,3-hexafluoro-1-propylmethyl carbonate and 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, among others EMC, DMC, DEC, and at least one selected from the group consisting of methyl propyl carbonate.
Specific examples of the above ester include methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl 2-fluoropropionate, and ethyl 2-fluoropropionate.

The electrolyte for non-aqueous electrolyte batteries of the present invention can also contain a polymer and is generally called a polymer solid electrolyte. Polymer solid electrolytes also include those containing non-aqueous organic solvents as plasticizers.

The polymer is not particularly limited as long as it is an aprotic polymer capable of dissolving the solute and the additive. Examples thereof include polymers having polyethylene oxide as a main chain or side chain, homopolymers or copolymers of polyvinylidene fluoride, methacrylic acid ester polymers, polyacrylonitrile, and the like. When adding a plasticizer to these polymers, an aprotic non-aqueous organic solvent is preferred among the above non-aqueous organic solvents.

(II) Solute For example, at least one cation selected from the group consisting of alkali metal ions and alkaline earth metal ions, hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, fluorosulfone acid anion, bis(trifluoromethanesulfonyl)imide anion, bis(fluorosulfonyl)imide anion, (trifluoromethanesulfonyl)(fluorosulfonyl)imide anion, bis(difluorophosphonyl)imide anion, (difluorophosphonyl)(fluorosulfonyl) An ionic salt comprising a pair of at least one anion selected from the group consisting of imide anions and (difluorophosphonyl)(trifluorosulfonyl)imide anions is preferred.

The cation of the ionic salt as the solute is lithium, sodium, potassium, or magnesium, and the anion is hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, or bis(trifluoromethanesulfonyl)imide. Anion, bis (fluorosulfonyl) imide anion, at least one selected from the group consisting of bis (difluorophosphonyl) imide anion, high solubility in the non-aqueous organic solvent and its electrochemical stability preferred from

The concentration of these solutes is not particularly limited, but the lower limit is 0.5 mol/L or more, preferably 0.7 mol/L or more, more preferably 0.9 mol/L or more, and the upper limit is 2.5 mol/L. /L or less, preferably 2.2 mol/L or less, more preferably 2.0 mol/L or less. If it is less than 0.5 mol/L, the cycle characteristics and output characteristics of the non-aqueous electrolyte battery decrease due to the decrease in ionic conductivity. An increase in viscosity also reduces ionic conduction, which may deteriorate the cycle characteristics and output characteristics of the non-aqueous electrolyte battery. Moreover, these solutes may be used singly or in combination.

When a large amount of the solute is dissolved in the non-aqueous organic solvent at once, the temperature of the non _- aqueous electrolyte may rise due to the heat of dissolution of the solute. In some cases, LiPF ₆ may decompose, which is not preferable.

In the non-aqueous electrolyte, the concentration of (III) is preferably 0.01% by mass or more and 2.00% by mass or less with respect to 100% by mass as the total amount of (I) to (IV). If it is 0.01% by mass or more, the effect of improving the characteristics of the non-aqueous electrolyte battery is likely to be obtained, while if it is 2.00% by mass or less, good durability is obtained without significantly increasing the Ni elution amount. It is easy to show an improvement effect. The range is more preferably 0.04% by mass or more and 1.00% by mass or less, and still more preferably 0.08% by mass or more and 0.50% by mass or less.

In the non-aqueous electrolyte, the concentration of (IV) is 0.01% by mass or more and 5.00% by mass or less with respect to 100% by mass of the total amount of (I) to (IV). If it is less than 0.01% by mass, the effect of reducing Ni elution from the Ni-rich positive electrode into the electrolyte cannot be sufficiently obtained. There is a concern that the capacity may decrease and the aluminum of the positive electrode current collector may be eluted. The range is more preferably 0.10% by mass or more and 2.50% by mass or less, and still more preferably 0.50% by mass or more and 1.50% by mass or less.

［一般式（６）中、Ｒ^９は炭素数２～５の炭化水素基であり、炭素数が３以上の場合は分枝構造をとってもよい。また、当該炭化水素基にはハロゲン原子やヘテロ原子や酸素原子が含まれていてもよい。］ Other Additives Additive components generally used in the electrolytic solution for non-aqueous electrolyte batteries of the present invention may be further added in an arbitrary ratio as long as they do not impair the gist of the present invention. Specific examples include cyclohexylbenzene, cyclohexylfluorobenzene, fluorobenzene (hereinafter sometimes referred to as FB), biphenyl, difluoroanisole, tert-butylbenzene, tert-amylbenzene, 2-fluorotoluene, 2-fluorobiphenyl , vinylene carbonate, dimethyl vinylene carbonate, vinyl ethylene carbonate, fluoroethylene carbonate, methyl propargyl carbonate, ethyl propargyl carbonate, dipropargyl carbonate, maleic anhydride, succinic anhydride, propanesultone, 1,3-propanesultone (hereinafter referred to as PS butane sultone, methylene methane disulfonate, dimethylene methane disulfonate, trimethylene methane disulfonate, compounds represented by the following general formula (6) (e.g., compounds in which R ⁹ is an ethylene group (hereinafter , sometimes referred to as "Dod"), compounds in which ^R9 is a propylene group (hereinafter sometimes referred to as "Dad"), compounds in which ^R9 is a butylene group, and R9 is a ^pentylene group compounds, compounds in which R ⁹ is a —CH ₂ —CH(C ₃ H ₇ )— group (hereinafter sometimes referred to as “pDod”)), methyl methanesulfonate, lithium difluorobis(oxalato)phosphate (hereinafter , LDFBOP), sodium difluorobis(oxalato)phosphate, potassium difluorobis(oxalato)phosphate, lithium difluorooxalatoborate (hereinafter sometimes referred to as LDFOB), difluorooxalatoborate sodium acid, potassium difluorooxalatoborate, lithium bis(oxalato)borate, sodium bis(oxalato)borate, potassium bis(oxalato)borate, lithium tetrafluorooxalatophosphate (hereinafter referred to as LTFOP) ), sodium tetrafluorooxalate, potassium tetrafluorooxalate, lithium tris(oxalato)phosphate, lithium difluorophosphate ₍ hereinafter sometimes referred to as _LiPO2F2 ), lithium fluorophosphate compounds having an overcharge prevention effect, a negative electrode film-forming effect, and a positive electrode protective effect, such as
The content of the other additive in the electrolytic solution is preferably 0.01% by mass or more and 8.00% by mass or less.

[In general formula (6), R ⁹ is a hydrocarbon group having 2 to 5 carbon atoms, and when the number of carbon atoms is 3 or more, it may have a branched structure. Further, the hydrocarbon group may contain a halogen atom, a heteroatom, or an oxygen atom. ]

In addition, when the content of the ionic salt mentioned as the solute in the electrolytic solution is less than 0.5 mol/L, which is the lower limit of the preferred concentration of the solute, the ionic salt is used as an “other additive” to form a negative electrode film. and positive electrode protection effect. In this case, the content in the electrolytic solution is preferably 0.01% by mass or more and 5.00% by mass. Examples of ionic salts in this case include lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate, magnesium trifluoromethanesulfonate, sodium fluorosulfonate, potassium fluorosulfonate, magnesium fluorosulfonate, Bis(trifluoromethanesulfonyl)imide lithium, bis(trifluoromethanesulfonyl)imide sodium, bis(trifluoromethanesulfonyl)imide potassium, bis(trifluoromethanesulfonyl)imide magnesium, bis(fluorosulfonyl)imide lithium, bis(fluorosulfonyl)imide sodium, bis(fluorosulfonyl)imide potassium, bis(fluorosulfonyl)imide magnesium, (trifluoromethanesulfonyl)(fluorosulfonyl)imide lithium, (trifluoromethanesulfonyl)(fluorosulfonyl)imide sodium, (trifluoromethanesulfonyl)(fluorosulfonyl) ) imide potassium, (trifluoromethanesulfonyl)(fluorosulfonyl)imide magnesium, bis(difluorophosphonyl)imide lithium, bis(difluorophosphonyl)imide sodium, bis(difluorophosphonyl)imide potassium, bis(difluorophosphonyl)imide magnesium, (difluorophosphonyl)(fluorosulfonyl)imide lithium, (difluorophosphonyl)(fluorosulfonyl)imide sodium, (difluorophosphonyl)(fluorosulfonyl)imide potassium, (difluorophosphonyl)(fluorosulfonyl)imide magnesium, (difluorophosphonyl)(trifluorosulfonyl)imide lithium, (difluorophosphonyl)(trifluorosulfonyl)imide sodium, (difluorophosphonyl)(trifluorosulfonyl)imide potassium, and (difluorophosphonyl)(trifluorosulfonyl) imidomagnesium and the like.

Furthermore, as in the case of non-aqueous electrolyte batteries called polymer batteries, the electrolyte for non-aqueous electrolyte batteries can be used after being quasi-solidified with a gelling agent or a cross-linked polymer.

2. Nonaqueous Electrolyte Battery The nonaqueous electrolyte battery of the present invention includes at least (a) the electrolyte for nonaqueous electrolyte batteries, (b) a positive electrode, and (c) a negative electrode. Furthermore, it is preferable to include (d) a separator, an outer package, and the like.

[(a) positive electrode]
(a) The positive electrode contains at least one oxide containing nickel as a positive electrode active material, and the nickel content in the metal contained in the positive electrode active material is 30 to 100% by mass.

[Positive electrode active material]
In the case of a lithium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly lithium, (a) the positive electrode active material constituting the positive electrode is not particularly limited as long as it is a material that can be charged and discharged. , for example, (A) nickel, or a lithium-transition metal composite oxide containing one or more metals selected from the group consisting of manganese, cobalt, and aluminum in addition to nickel and having a layered structure, (B) a spinel structure (C) a lithium-containing olivine-type phosphate, and (D) a lithium-excess layered transition metal oxide having a layered rock salt structure.

((A) lithium transition metal composite oxide)
Positive electrode active material (A) Nickel or a lithium-transition metal composite oxide containing one or more metals selected from the group consisting of manganese, cobalt, and aluminum in addition to nickel and having a layered structure includes, for example, lithium - Nickel composite oxides, lithium-nickel-cobalt composite oxides, lithium-nickel-manganese composite oxides, lithium-nickel-manganese-cobalt composite oxides, and the like. In addition, some of the transition metal atoms that are the main constituent of these lithium-transition metal composite oxides are You may use what substituted with other elements, such as.

Specific examples of lithium-nickel composite oxides include _LiNiO2 , lithium nickel oxide to which dissimilar elements such as Mg, Zr, Al, and Ti are added, and _LiNiO2 particle powder in which part of the particle surface is coated with aluminum oxide. may be used.

Lithium-nickel-cobalt composite oxides and composite oxides in which part of nickel-cobalt is substituted with Al or the like are represented by general formula [1-1].
Li _a Ni _1-bc Co _b M ¹ _c O ₂ [1-1]
In formula [1-1], M ¹ is at least one element selected from the group consisting of Al, Fe, Mg, Zr, Ti and B, a is 0.9 ≤ a ≤ 1.2, and b , c satisfy the conditions of 0.1≦b≦0.3 and 0≦c≦0.1.
These can be prepared, for example, according to the production method described in JP-A-2009-137834. Specifically, LiNi _0.8 Co _0.2 O ₂ , LiNi _0.85 Co _0.10 Al _0.05 O ₂ , LiNi _0.87 Co _0.10 Al _0.03 O ₂ , LiNi _0.6 Co _0.3 Al _0.1 O ₂ and the like.

Specific examples of the lithium-nickel-manganese composite oxide include LiNi _0.5 Mn _0.5 O ₂ and the like.

Lithium-nickel-manganese-cobalt composite oxides and composite oxides in which part of nickel-manganese-cobalt is substituted with Al or the like include lithium-containing composite oxides represented by general formula [1-2].
_{LidNieMnfCogM2hO2 [} ^1-2 _{] _ _ _}
In formula [ ^1-2 ], M2 is at least one element selected from the group consisting of Al, Fe, Mg, Zr, Ti, B, and Sn, and d satisfies 0.9 ≤ d ≤ 1.2. , e, f, g, and h satisfy the conditions e+f+g+h=1, 0≦e≦0.7, 0≦f≦0.5, 0≦g≦0.5, and h≧0.
The lithium-nickel-manganese-cobalt composite oxide contains manganese within the range shown in the general formula [1-2] in order to improve structural stability and improve safety at high temperatures in lithium secondary batteries. More preferably, it further contains cobalt in the range represented by the general formula [1-2] in order to improve the high rate characteristics of the lithium ion secondary battery.
Specifically, for example, Li[Ni _1/3 Mn _1/3 Co _1/3 ]O ₂ and Li[Ni _0.45 Mn _0.35 Co _0.2 ] having a charge/discharge range at 4.3 V or higher _O2 , _Li [ _{Ni0.5Mn0.3Co0.2} ] _O2 , _Li [ _{Ni0.6Mn0.2Co0.2} ] _{O2 , Li [ Ni0.49Mn0.3Co 0.2Zr0.01} ] _{O2 , Li} [ _{Ni0.49Mn0.3Co0.2Mg0.01 ] O2 and} the like.

((B) Nickel-containing lithium-manganese composite oxide having a spinel structure)
Positive electrode active material (B) Examples of lithium-manganese composite oxides having a spinel structure include spinel-type lithium-manganese composite oxides represented by general formula [1-3].
Li _j (Mn _2-k M ³ _k )O ₄ [1-3]
In formula [ ^1-3 ], M3 contains Ni and may contain at least one metal element selected from the group consisting of Co, Fe, Mg, Cr, Cu, Al and Ti. j is 1.05≤j≤1.15 and k is 0<k≤0.20.
Specifically, for example, LiMn _1.9 Ni _0.1 O ₄ , LiMn _1.5 Ni _0.5 O ₄ and the like can be mentioned.

((C) olivine-type lithium phosphate)
Examples of the positive electrode active material (C) olivine-type lithium phosphate include those represented by general formula [1-4].
LiFe _1-n M ⁴ _n PO ₄ [1-4]
In formula [ ^1-4 ], M4 contains Ni, and is at least one selected from Co, Mn, Cu, Zn, Nb, Mg, Al, Ti, W, Zr and Cd, and n is , 0<n≦1.
Specific examples include LiNiPO ₄ and the like.

((D) lithium-excess layered transition metal oxide)
As the positive electrode active material (D), the nickel-containing lithium-excess layered transition metal oxide having a layered rock salt structure includes, for example, those represented by general formula [1-5].
xLiM ⁵ O _2. (1-x)Li ₂ M ⁶ O ₃ [1-5]
In formula [1-5], x is a number that satisfies 0<x< ¹ , M5 is at least one metal element having an average oxidation number of ³⁺ , and ^M6 is an average oxidation number. At least one metallic element whose number is 4 ⁺ . In formula [1-5], M ⁵ is preferably one kind of metal element selected from trivalent Mn, Ni, Co, Fe, V, and Cr, but equivalent amounts of divalent and tetravalent may have an average oxidation number of trivalent.
^In formula [1-5], M6 is preferably one or more metal elements selected from Mn, Zr and Ti. Note that nickel is always included in either M ⁵ or M ⁶ . Specifically, 0.5 [LiNi _0.5 Mn _0.5 O ₂ ]·0.5 [Li ₂ MnO ₃ ], 0.5 [LiNi _1/3 Co _1/3 Mn _1/3 O ₂ ] · 0.5 [Li ₂ MnO ₃ ], 0.5 [LiNi _0.375 Co _0.25 Mn _0.375 O ₂ ] · 0.5 [Li ₂ MnO ₃ ], 0.5 [LiNi _0.375 Co _{0.125Fe0.125Mn0.375O2} ] _.0.5 [ _Li2MnO3 ] _{, 0.45} [ _{LiNi0.375Co0.25Mn0.375O2 ] .0.10 [ Li 2} TiO ₃ ]·0.45[Li ₂ MnO ₃ ] and the like.
It is known that the positive electrode active material (D) represented by this general formula [1-5] exhibits high capacity when charged at a high voltage of 4.4 V (based on Li) or higher (for example, US Patent 7 , 135,252).
These positive electrode active materials can be prepared, for example, according to the production methods described in JP-A-2008-270201, WO2013/118661, JP-A-2013-030284, and the like.

The positive electrode active material contains at least one selected from the above (A) to (D) as a main component, contains one or more oxides containing at least nickel, and contains the metal contained in the positive electrode active material The nickel content may be 30 to 100% by mass, but other substances included include, for example, transition element chalcogenides such as FeS ₂ , TiS ₂ , TiO ₂ , V ₂ O ₅ , MoO ₃ and MoS ₂ , Alternatively, conductive polymers such as polyacetylene, polyparaphenylene, polyaniline, and polypyrrole, activated carbon, radical-generating polymers, and carbon materials can be used.

[Positive collector]
(b) The positive electrode has a positive electrode current collector. As the positive electrode current collector, for example, aluminum, stainless steel, nickel, titanium, alloys thereof, or the like can be used.

[Positive electrode active material layer]
(a) The positive electrode has, for example, a positive electrode active material layer formed on at least one surface of a positive electrode current collector. The positive electrode active material layer is composed of, for example, the positive electrode active material described above, a binder, and, if necessary, a conductive agent.
Binders include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, styrene-butadiene rubber (SBR), carboxymethylcellulose, methylcellulose, cellulose acetate phthalate, hydroxypropylmethylcellulose, and polyvinyl alcohol. etc.
Examples of conductive agents that can be used include carbon materials such as acetylene black, ketjen black, furnace black, carbon fiber, graphite (granular graphite and scale-like graphite), and fluorinated graphite. For the positive electrode, it is preferable to use acetylene black or ketjen black with low crystallinity.

[(C) Negative electrode]
The negative electrode material is not particularly limited, but in the case of lithium batteries and lithium ion batteries, lithium metal, alloys and intermetallic compounds of lithium metal and other metals, various carbon materials (artificial graphite, natural graphite, etc.), metals Oxides, metal nitrides, tin (single substance), tin compounds, silicon (single substance), silicon compounds, activated carbon, conductive polymers and the like are used.

The carbon material includes, for example, graphitizable carbon, non-graphitizable carbon (hard carbon) having a (002) plane spacing of 0.37 nm or more, and graphite having a (002) plane spacing of 0.34 nm or less. and so on. More specifically, there are thermally decomposable carbon, cokes, glassy carbon fibers, baked organic polymer compounds, activated carbon, carbon blacks, and the like. Among them, cokes include pitch coke, needle coke, petroleum coke, and the like. A calcined organic polymer compound refers to a product obtained by calcining a phenol resin, a furan resin, or the like at an appropriate temperature to carbonize it. A carbon material is preferable because it has a very small change in crystal structure due to the absorption and desorption of lithium, so that a high energy density can be obtained and excellent cycle characteristics can be obtained. The shape of the carbon material may be fibrous, spherical, granular, or scaly. Amorphous carbon or a graphite material having a surface coated with amorphous carbon is more preferable because the reactivity between the surface of the material and the electrolytic solution is low.

(c) The negative electrode preferably contains at least one negative electrode active material.

[Negative electrode active material]
In the case of a lithium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly lithium, (c) the negative electrode active material constituting the negative electrode is capable of doping and dedoping lithium ions, for example (E ) a carbon material having a lattice plane (002 plane) d value of 0.340 nm or less in X-ray diffraction, (F) a carbon material having a lattice plane (002 plane) d value of more than 0.340 nm in X-ray diffraction, (G ) oxides of one or more metals selected from Si, Sn and Al, (H) one or more metals selected from Si, Sn and Al or alloys containing these metals or alloys of these metals or alloys and lithium and (I) containing at least one selected from lithium titanium oxide. One of these negative electrode active materials can be used alone, or two or more of them can be used in combination.

((E) a carbon material having a lattice plane (002 plane) d value of 0.340 nm or less in X-ray diffraction)
Negative electrode active material (E) Examples of carbon materials having a lattice plane (002 plane) d value of 0.340 nm or less in X-ray diffraction include pyrolytic carbons and cokes (e.g., pitch coke, needle coke, petroleum coke, etc.). , graphites, organic polymer compound calcined bodies (for example, phenol resin, furan resin, etc. calcined at an appropriate temperature and carbonized), carbon fibers, activated carbon, etc. These may be graphitized. The carbon material has a lattice spacing (d002) between (002) planes of 0.340 nm or less as measured by an X-ray diffraction method, and is graphite or graphite having a true density of 1.70 g/cm ³ or more. Highly crystalline carbon materials with similar properties are preferred.

((F) a carbon material in which the d value of the lattice plane (002 plane) in X-ray diffraction exceeds 0.340 nm)
Negative electrode active material (F) Carbon materials in which the d value of the lattice plane (002 plane) in X-ray diffraction exceeds 0.340 nm include amorphous carbon, which is heat-treated at a high temperature of 2000 ° C. or higher. is also a carbon material in which the stacking order hardly changes. For example, non-graphitizable carbon (hard carbon), mesocarbon microbeads (MCMB) fired at 1500° C. or less, mesopasbitch carbon fiber (MCF), and the like are exemplified. Carbotron (registered trademark) P manufactured by Kureha Corporation is a typical example.

((G) one or more metal oxides selected from Si, Sn and Al)
Negative electrode active material (G) The oxide of one or more metals selected from Si, Sn, and Al includes, for example, silicon oxide and tin oxide, which can be doped/dedoped with lithium ions.
There is _SiOx , etc., which has a structure in which ultrafine particles of Si are dispersed in _SiO2 . When this material is used as a negative electrode active material, charging and discharging are performed smoothly because the Si that reacts with Li is ultrafine particles, while the SiO _x particles having the above structure themselves have a small surface area, so the negative electrode active material layer The composition (paste) for forming the coating property and the adhesion of the negative electrode mixture layer to the current collector are also good.
Since SiO _x undergoes a large volume change during charging and discharging, by using SiO _x and graphite of the negative electrode active material (E) in a specific ratio as the negative electrode active material, the capacity can be increased and good charge-discharge cycle characteristics can be obtained. can be compatible with

((H) One or more metals selected from Si, Sn, and Al, alloys containing these metals, or alloys of these metals or alloys and lithium)
Negative electrode active material (H) One or more metals selected from Si, Sn, and Al, alloys containing these metals, or alloys of these metals or alloys and lithium include, for example, metals such as silicon, tin, and aluminum, and silicon alloys , tin alloys, aluminum alloys, etc., and materials obtained by alloying these metals or alloys with lithium during charging and discharging can also be used.
Preferred specific examples thereof include simple metals such as silicon (Si) and tin (Sn) (for example, in powder form) and metal alloys described in WO2004/100293 and JP-A-2008-016424. , a compound containing the metal, an alloy containing tin (Sn) and cobalt (Co) in the metal, and the like. When the metal is used for the electrode, it is preferable because high charge capacity can be exhibited and the expansion/contraction of the volume due to charge/discharge is relatively small. In addition, these metals are known to exhibit high charge capacity when used for the negative electrode of a lithium ion secondary battery because they are alloyed with Li during charging, which is also preferable.
Furthermore, a negative electrode active material formed of silicon pillars with a submicron diameter, a negative electrode active material made of fibers composed of silicon, and the like, which are described in WO2004/042851, WO2007/083155, etc., for example, may also be used. .

((I) lithium titanium oxide)
Examples of the negative electrode active material (I) lithium titanium oxide include lithium titanate having a spinel structure and lithium titanate having a ramsdellite structure.
Lithium titanate having a spinel structure includes, for example, Li _4+α Ti ₅ O ₁₂ (α changes within the range of 0≦α≦3 depending on the charge/discharge reaction). Lithium titanate having a ramsdellite structure includes, for example, Li _2+β Ti ₃ O ₇ (β varies within the range of 0≦β≦3 depending on the charge/discharge reaction). These negative electrode active materials can be prepared, for example, according to the production methods described in JP-A-2007-018883, JP-A-2009-176752, and the like.
For example, in the case of a sodium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly sodium, hard carbon, oxides such as TiO ₂ , V ₂ O ₅ and MoO ₃ are used as the negative electrode active material. For example, in the case of a sodium ion secondary battery in which the cation in the non-aqueous electrolyte is mainly sodium, sodium-containing transition metal composite oxides such as NaFeO ₂ , NaCrO ₂ , NaNiO ₂ , NaMnO ₂ and NaCoO ₂ as the positive electrode active material, A mixture of a plurality of transition metals such as Fe, Cr, Ni, Mn, and Co in those sodium-containing transition metal composite oxides, and a part of the transition metals in these sodium-containing transition metal composite oxides other than other transition metals transition metal phosphate _compounds such as _Na2FeP2O7 and _{NaCo3 ( PO4} ) _{2P2O7 ; sulfides} such as _TiS2 and _FeS2 ; Conductive polymers such as phenylene, polyaniline, and polypyrrole, activated carbon, radical-generating polymers, and carbon materials are used.

[Negative electrode current collector]
(c) The negative electrode has a negative electrode current collector. As the negative electrode current collector, for example, copper, stainless steel, nickel, titanium, alloys thereof, or the like can be used.

[Negative electrode active material layer]
(c) For the negative electrode, for example, a negative electrode active material layer is formed on at least one surface of a negative electrode current collector. The negative electrode active material layer is composed of, for example, the negative electrode active material described above, a binder, and, if necessary, a conductive agent.
Binders include polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, styrene-butadiene rubber (SBR), carboxymethylcellulose, methylcellulose, cellulose acetate phthalate, hydroxypropylmethylcellulose, and polyvinyl alcohol. etc.
Examples of conductive agents that can be used include carbon materials such as acetylene black, ketjen black, furnace black, carbon fiber, graphite (granular graphite and scale-like graphite), and fluorinated graphite.

[Method for producing electrodes ((a) positive electrode and (c) negative electrode)]
The electrode is obtained, for example, by dispersing and kneading an active material, a binder, and, if necessary, a conductive agent in a predetermined compounding amount in a solvent such as N-methyl-2-pyrrolidone (NMP) or water. The paste can be applied to a current collector and dried to form an active material layer. The obtained electrode is preferably compressed by a method such as a roll press to adjust the density of the electrode to an appropriate one.

[(d) Separator]
The above non-aqueous electrolyte battery can be provided with (d) a separator. As a separator for preventing contact between (a) the positive electrode and (c) the negative electrode, a nonwoven fabric or porous sheet made of polyolefin such as polypropylene or polyethylene, cellulose, paper, glass fiber, or the like is used. These films are preferably microporous so that the electrolytic solution permeates them and the ions easily permeate them.
Examples of the polyolefin separator include a membrane such as a microporous polymer film such as a porous polyolefin film that electrically insulates the positive electrode and the negative electrode and is permeable to lithium ions. As a specific example of the porous polyolefin film, for example, a porous polyethylene film may be used alone, or a porous polyethylene film and a porous polypropylene film may be laminated to form a multilayer film. Moreover, the film etc. which combined the porous polyethylene film and the polypropylene film are mentioned.

[Exterior body]
In constructing the non-aqueous electrolyte battery, as the exterior body of the non-aqueous electrolyte battery, for example, a coin-shaped, cylindrical, square-shaped metal can, or a laminate exterior body can be used. Metal can materials include, for example, nickel-plated steel plates, stainless steel plates, nickel-plated stainless steel plates, aluminum or its alloys, nickel, and titanium.
As the laminated exterior body, for example, an aluminum laminated film, a SUS laminated film, a silica-coated polypropylene or polyethylene laminated film, or the like can be used.

The configuration of the non-aqueous electrolyte battery according to the present embodiment is not particularly limited. can be configured. The shape of the non-aqueous electrolyte battery is not particularly limited, but an electrochemical device having a shape such as a coin shape, a cylindrical shape, a rectangular shape, or an aluminum laminate sheet shape is assembled from the above components.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these descriptions.

[Preparation of NCM811 positive electrode]
91.0% by mass of LiNi _0.8 Mn _0.1 Co _0.1 O ₂ powder was mixed with 4.5% by mass of polyvinylidene fluoride (PVDF) as a binder and 4.5% by mass of acetylene black as a conductive material. -2-Pyrrolidone (hereinafter referred to as NMP) was added to prepare a positive electrode mixture paste. This paste was applied to both sides of an aluminum foil (A1085), dried and pressed, and then punched out into a size of 4×5 cm to obtain an NCM811 positive electrode for testing.

[Preparation of NCA positive electrode]
89.0% by mass of LiNi _0.87 Co _0.10 Al _0.03 O ₂ powder was mixed with 5.0% by mass of PVDF as a binder and 6.0% by mass of acetylene black as a conductive material, and NMP was added to prepare a positive electrode mixture paste. was made. This paste was applied to both sides of an aluminum foil (A1085), dried and pressed, and then punched out to a size of 4×5 cm to obtain an NCA positive electrode for testing.

[Preparation of graphite negative electrode]
92.0% by mass of artificial graphite powder was mixed with 8.0% by mass of PVDF as a binder, and NMP was further added to prepare a negative electrode mixture paste. This paste was applied to one side of a copper foil, dried and pressed, and then punched out into a size of 4×5 cm to obtain a graphite negative electrode for testing.

[Synthesis of Silicon Compound Having Unsaturated Bond Represented by General Formula (1)]
A silicon compound having a substituent having an unsaturated bond represented by the general formula (1) can be produced by various methods. Although the production method is not limited, for example, ethynyltrichlorosilane, diethynyldichlorosilane, triethynyl is produced by reacting silicon tetrachloride and an ethynyl Grignard reagent in tetrahydrofuran at an internal temperature of 40° C. or less. Chlorosilane, tetraethynylsilane (1-15) is obtained. At this time, after adjusting the amount of the ethynyl Grignard reagent to be used and reacting it, it is possible to separate these silicon compounds by distilling under reduced pressure at an internal temperature of 100° C. or lower.

And (1-1), (1-2), (1-3), (1-4), (1-6), (1-7), (1-8), (1-10) are It was easily obtained by reacting triethynylchlorosilane as a starting material with 1 equivalent of the corresponding alcohol in the presence of a base such as triethylamine. Similarly, (1-11), (1-13), (1-14), (1-16), (1-28) are the corresponding organolithium reagents with 1 equivalent to triethynylchlorosilane, or Grignard reagents. , or obtained by reacting potassium fluoride.

(1-5) is obtained by reacting diethynyldichlorosilane with 2 equivalents of methanol in the presence of a base such as triethylamine, (1-17) is obtained by reacting 2 equivalents of an allyl Grignard reagent, and (1-19) ) was obtained by reaction with 2 equivalents of sodium acetylide. (1-25), (1-26), and (1-27) are reacted with diethynyldichlorosilane in the presence of a base with 1 equivalent of the corresponding alcohol or organolithium reagent, followed by 1 equivalent of fluorine. It was obtained by reacting potassium chloride.

Furthermore, (1-9) and (1-20) were obtained by reacting ethynyltrichlorosilane as a raw material with 3 equivalents of propargyl alcohol or sodium acetylide.

(1-12) is obtained by reacting phenyltrichlorosilane with 3 equivalents of an ethynyl Grignard reagent. obtained by reacting

(1-24) was obtained by reacting trichloromethylsilane with 3 equivalents of an ethynyl Grignard reagent. (1-21), (1-22), and (1-23) are reacted with 2 equivalents of an ethynyl Grignard reagent with trichloromethylsilane, followed by 1 equivalent of the corresponding alcohol in the presence of a base such as triethylamine, Alternatively, it was obtained by reacting an organic lithium reagent.

[About (IV)]
Ammonium fluorosulfonate was obtained by neutralizing commercial fluorosulfonic acid with 1 equivalent of ammonia while cooling to 0°C. LiSO ₃ F was obtained by adding lithium chloride to this ammonium fluorosulfonate and performing cation exchange.
The ethenesulfonyl fluoride (hereinafter sometimes referred to as “compound (2-1)”) used was from Aldrich.
In addition, methanesulfonyl chloride manufactured by Aldrich, benzenesulfonyl chloride manufactured by Tokyo Chemical Industry Co., Ltd., phenyl dichlorophosphate, and phenyldichlorophosphine oxide manufactured by Wako Pure Chemical Industries, Ltd. were each fluorinated with potassium fluoride to obtain methanesulfonyl fluoride. (hereinafter sometimes referred to as "compound (2-4)"), benzenesulfonyl fluoride (hereinafter sometimes referred to as "compound (2-2)"), phenyl difluorophosphate (hereinafter, " Compound (4-1)") and phenyldifluorophosphine oxide (hereinafter sometimes referred to as "Compound (4-2)") were obtained.
Also, trifluoromethanesulfonyl fluoride (hereinafter sometimes referred to as "compound (2-3)") used was manufactured by Central Glass.
Lithium ethylfluorophosphate (hereinafter sometimes referred to as “compound (3-1)”) was obtained by reacting lithium difluorophosphate with ethanol.
Compounds (5-1) and (5-3) shown below are tetrahydrothiophen-3-ol-1,1-dioxide available from Combi-blocks and methanesulfonyl chloride available from Aldric, or non-patent document 1. obtained by reaction with chlorodifluorophosphine oxide synthesized by chlorinating potassium difluorophosphate with phosphorus oxychloride by the method described in .
Further, the compound (5-2) shown below is prepared by reacting the above tetrahydrothiophen-3-ol-1,1-dioxide with 2-chloroethanesulfonyl chloride manufactured by Tokyo Kasei Kogyo Co., Ltd., and then reacting it with triethylamine to remove it. It was obtained by forming a double bond with hydrochloric acid.
Further, 2-hydroxy-1,3-propane sultone synthesized by reacting sodium 2,3-dihydroxypropanesulfonate with thionyl chloride by the method described in Patent Document 10 and then treating with an aqueous hydrochloric acid solution, The following compound (5-4) was obtained by reacting with the above chlorodifluorophosphine oxide.

[Preparation of LiPF ₆ solution (DMC, EMC)]
Synthesis of LiPF ₆ concentrate was carried out according to the method disclosed in US Pat. That is, after synthesizing lithium phosphate hexachloride by reacting phosphorus trichloride, lithium chloride and chlorine in a carbonate ester (DMC or EMC), hydrogen fluoride is introduced to fluorinate, A DMC solution and an EMC solution containing LiPF ₆ , hydrogen chloride and unreacted hydrogen fluoride were obtained. By concentrating this under reduced pressure, a concentrated LiPF ₆ solution from which almost all of the hydrogen chloride and most of the hydrogen fluoride were removed was obtained. In order to remove the remaining hydrogen fluoride, after adding each carbonate ester to adjust the concentration to 30.0% by mass and lowering the viscosity, 10% by mass of dehydrated ion exchange resin is added to each 100 g of the concentrated liquid, A purification process was performed. This resulted in a 30.0 wt% _LiPF6 /DMC solution and a 30.0 wt% _LiPF6 /EMC solution.

[Preparation of reference electrolyte]
The 30.0% by mass LiPF ₆ /EMC solution prepared above and EMC, DEC, and EC, which are non-aqueous solvents, were mixed with a LiPF ₆ concentration of 1.0 M and a solvent ratio (volume) of EMC:DEC:EC. = 4:2:3, and this was used as Reference Electrolyte 1.
Similarly, a 30.0% by mass LiPF ₆ /DMC solution, DMC and EC were mixed so that the LiPF ₆ concentration was 1.0 M and the solvent ratio (volume) was DMC:EC = 2:1. was used as reference electrolyte 2.

[Preparation of non-aqueous electrolyte solutions according to Examples and Comparative Examples]
A silicon compound (1-1) corresponding to 0.25% by mass was added to the standard electrolyte solution 1 and dissolved by stirring for 1 hour. This was designated as non-aqueous electrolyte 1-(1-1)-0.25-(0).
Next, silicon compound (1-1) corresponding to 0.25% by mass and LiSO ₃ F corresponding to 0.02% by mass were added to reference electrolyte solution 1 and dissolved by stirring for 1 hour. This was designated as non-aqueous electrolyte 1-(1-1)-0.25-LiSO3F-0.02.

Similarly, as shown in Table 2,
The components (III) and (IV) were added to the standard electrolyte solution 1 at concentrations shown in Table 2, and dissolved by stirring to obtain respective non-aqueous electrolyte solutions.

Similarly, as shown in Table 3,
The components (III), (IV), and other solutes or additive components were added to the reference electrolytic solution 1 so as to have the concentrations shown in Table 3, and the respective non-aqueous electrolysis was performed by stirring and dissolving. I got the liquid.

In the table, LiPO ₂ F ₂ means lithium difluorophosphate, LTFOP means lithium tetrafluorooxalatophosphate, LDFBOP means lithium difluorobis(oxalato)phosphate, LDFOB means difluorooxalato means lithium borate, LiFSI means lithium bis(fluorosulfonyl)imide, LTFFSI means lithium (trifluoromethanesulfonyl)(fluorosulfonyl)imide, LDFPI means lithium bis(difluorophosphonyl)imide .

Similarly, as shown in Table 4,
The components (III) and (IV) were added to the standard electrolyte solution 2 at concentrations shown in Table 4, and dissolved by stirring to obtain respective non-aqueous electrolyte solutions.

Similarly, as shown in Table 5,
The components (III), (IV), and other solutes or additive components were added to the reference electrolyte solution 2 so as to have the concentrations shown in Table 5, and the respective non-aqueous electrolysis was performed by stirring and dissolving. I got the liquid.

[Preparation of non-aqueous electrolyte battery] NCM811 / graphite In an argon atmosphere with a dew point of -50 ° C. or less, after welding a terminal to the above-mentioned NCM811 positive electrode, both sides were sandwiched between two polyethylene separators (5 × 6 cm), and further Two graphite negative electrodes, to which terminals were previously welded, were sandwiched so that the surface of the negative electrode active material faced the surface of the positive electrode active material. Then, they were placed in an aluminum laminate bag with an opening on one side left, and after vacuum injection of a non-aqueous electrolyte, the opening was sealed with heat to obtain Examples 1-1 to 1-39. , aluminum laminate type batteries according to Comparative Examples 1-1 to 1-32 were produced. As the non-aqueous electrolyte, those shown in Tables 2 and 3 were used.

[Initial charge/discharge]
The assembled battery had a capacity of 73 mAh standardized by the weight of the positive electrode active material. The battery was placed in a constant temperature bath at 25° C. and connected to a charging/discharging device in that state. The battery was charged to 4.2 V at a charging rate of 0.2 C (current value for full charge in 5 hours). After maintaining 4.2V for 1 hour, the battery was discharged to 3.0V at a discharge rate of 0.2C. This was regarded as one charge/discharge cycle, and a total of 3 cycles of charge/discharge were performed to stabilize the battery.

[Capacity measurement test after 400 cycles (cycle characteristics evaluation)]
Next, the battery was placed in a constant temperature bath at 50° C. and allowed to stand for 2 hours, and then charged to 4.2 V at a charge rate of 2C. After reaching 4.2 V, the voltage was maintained for 1 hour and then discharged to 3.0 V at a discharge rate of 2C. This charging/discharging at 2C in an environment of 50°C was repeated 400 cycles. Then, the capacity retention rate after the cycle was calculated from the following formula.
Capacity retention rate [%] = (discharge capacity after 400 cycles/discharge capacity at 1st cycle) x 100

[Ni elution amount measurement]
After 400 cycles, the battery was disassembled in an environment not exposed to the air, and the negative electrode was taken out. The collected negative electrode was washed with dimethyl carbonate and then collected by scraping off the active material layer on the current collector. The recovered active material layer was added to a 14.0% by mass high-purity nitric acid aqueous solution and heated at 150° C. for 2 hours. An aqueous solution obtained by dissolving the total amount of the residue in ultrapure water is measured with an inductively coupled plasma atomic emission spectrometer (manufactured by Shimadzu Corporation ICPS-7510), and the amount of Ni component contained in the active material layer [μg / g]. (Ni component/negative electrode active material layer) was determined. Only the test negative electrode obtained in paragraph [0074] (test negative electrode before being incorporated into the battery) was similarly washed with dimethyl carbonate, and then the active material layer on the current collector was scraped off and collected. The recovered active material layer was subjected to the same treatment as described above, and the amount of Ni contained in the negative electrode active material layer was measured using an inductively coupled plasma atomic emission spectrometer. Ni component/negative electrode active material layer), it can be said that all of the Ni component quantified from the negative electrode active material layer taken out from the battery after 400 cycles was eluted from the positive electrode active material.

Tables 6 and 7 show the evaluation results of the battery with the electrode configuration of NCM811/graphite. Regarding Comparative Examples 1-9, 1-10, and Examples 1-13 to 1-17, the capacity retention rate and Ni elution after 400 cycles of Comparative Example 1-9 using an electrolytic solution containing no component (III) It was shown as a relative value when each amount was set to 100. In addition, regarding the other examples and comparative examples, the capacity retention rate after 400 cycles and the Ni elution amount of the comparative example using the electrolytic solution having the composition that does not contain the component (IV) in each electrolytic solution composition It was shown as a relative value when set to 100.

The silicon compound (1-1) was used, the amount added was fixed at 0.25% by mass, which is within the particularly preferred range of 0.08 to 0.50% by mass, and the amount of LiSO ₃ F was adjusted to 0.25% by mass. When the content was changed from 00% by mass to 5.50% by mass, the elution of Ni tended to be suppressed as the amount of LiSO ₃ F increased. Up to 2.40% by mass of LiSO ₃ F, the amount of Ni eluted was suppressed and the capacity retention ratio was improved (Examples 1-1 to 1-5, Comparative Example 1-1). At 4.50% by mass, the capacity retention rate was not further improved (Example 1-6), and at 5.50% by mass, the capacity retention rate was lower than 2.40 and 4.50% by mass. was observed to decrease (Comparative Example 1-2). It is believed that this is because the amount of addition is too large, and adverse effects on the aluminum and the like of the positive electrode current collector have become apparent.

When the results using silicon compounds (1-2), (1-12), and (1-15) were compared, the same tendency as when using (1-1) was confirmed (Example 1-7 1-12, Comparative Examples 1-3 to 1-8). As the amount of LiSO ₃ F increased from 0.00% by mass to 0.60% by mass and then to 1.40% by mass, not only the capacity retention rate improved but also the Ni elution amount decreased. In addition, when adding 5.50% by mass, although further suppression of Ni elution was confirmed, a decrease in capacity retention rate was observed when compared to 1.40% by mass, and the aluminum etc. of the positive electrode current collector were adversely affected. It was found to have manifested itself.

As is clear from the results of Examples 1-1 to 1-6, it is up to the addition of 2.40% by mass of LiSO ₃ F that both the capacity retention rate and the suppression of Ni elution are improved. However, in further long-term tests and tests at elevated temperatures, it is possible that even if the amount of LiSO ₃ F added is less, an adverse effect on the aluminum etc. of the positive electrode current collector may be seen. , LiSO ₃ F addition cost and increase range of performance improvement, 0.10 to 2.50% by mass is a more balanced addition amount, and 0.50 to 1.50% by mass can be said to be a particularly well-balanced addition amount.
Therefore, in the following examples and comparative examples, experiments were conducted with the amount of LiSO ₃ F added fixed at 1.00% by mass, which is within the particularly preferred range of 0.50 to 1.50% by mass.

As described above, the amount of LiSO ₃ F was fixed at 1.00% by mass, and the amount of silicon compound (1-1) added was increased from 0.00 to 2.50% by mass. As a result (Comparative Examples 1-9, 1-10, Examples 1-13 to 1-17), a gradual improvement in the capacity retention rate was observed when the amount added was from 0.02% by mass to 1.50% by mass. An increase in the Ni elution amount was observed (Examples 1-13 to 1-17). On the other hand, when the added amount was increased to 2.50% by mass, only an increase in the Ni elution amount was confirmed without an improvement in the capacity retention ratio (Comparative Example 1-10).

Naturally, it is desired to improve the capacity retention rate as much as possible while suppressing the elution of Ni. From the results of Comparative Examples 1-9, 1-10, and Examples 1-13 to 1-17 above, the concentration of the silicon compound having an unsaturated bond represented by general formula (1) is 0.01 to 2.00. Examples 1-13 to 1-17, which are % by mass, tend to exhibit a good effect of improving durability without significantly increasing the Ni elution amount. Furthermore, Examples 1-14 to 1-16 in which the concentration is 0.04 to 1.00% by mass are more likely to exhibit the above effects, and the concentration is 0.08 to 0.50% by mass. Examples 1-15 and 1-16 are particularly likely to exhibit the above effects.
In the following examples, the amount of LiSO ₃ F added (the amount of component (IV) added) was fixed at 1.00% by mass, which is within the particularly preferred range of 0.50 to 1.50% by mass. It is carried out.
Further, in the following examples and comparative examples, the addition amount of the silicon compound having an unsaturated bond represented by the general formula (1) was set to 0.08 to 0.50% by mass, which is a particularly preferable range. The experiment is conducted by fixing it to 25% by mass.

Comparative Examples 1-11 to 1-20 and Examples 1-18 to 1-27 show the results of evaluation when different types of silicon compounds having unsaturated bonds represented by general formula (1) were used. In both cases, it was clearly confirmed that the system to which 1.00% by mass of LiSO ₃ F was added improved the capacity retention rate and inhibited Ni elution compared to the system to which LiSO ₃ F was not added.

In Comparative Examples 1-21 to 1-32 and Examples 1-28 to 1-39, the type of silicon compound having an unsaturated bond represented by general formula (1) was changed, and various other solutes or additive components were used. The evaluation results when containing are shown. In both cases, it was clearly confirmed that the system to which 1.00% by mass of LiSO ₃ F was added improved the capacity retention rate and inhibited Ni elution compared to the system to which LiSO ₃ F was not added.

[Preparation of non-aqueous electrolyte battery] NCA/graphite In an argon atmosphere with a dew point of −50° C. or less, after welding a terminal to the NCA positive electrode described above, the both sides were sandwiched between two polyethylene separators (5×6 cm), and further Two graphite negative electrodes, to which terminals were previously welded, were sandwiched on the outer side so that the surface of the negative electrode active material faced the surface of the positive electrode active material. Then, they are put in an aluminum laminate bag with an opening on one side left, and after vacuum injection of a non-aqueous electrolyte, the opening is sealed with heat to obtain Examples 2-1 and 2- 18, aluminum laminate type batteries according to Comparative Examples 2-1 to 2-18 were produced. As the non-aqueous electrolyte, those shown in Tables 4 and 5 were used.

[Initial charge/discharge]
The assembled battery had a capacity of 70 mAh standardized by the weight of the positive electrode active material. The battery was placed in a constant temperature bath at 25° C. and connected to a charging/discharging device in that state. The battery was charged to 4.1 V at a charging rate of 0.2 C (current value for full charge in 5 hours). After maintaining 4.1V for 1 hour, the battery was discharged to 2.7V at a discharge rate of 0.2C. This was regarded as one charge/discharge cycle, and a total of 3 cycles of charge/discharge were performed to stabilize the battery.

[Capacity measurement test after 400 cycles (cycle characteristics evaluation)]
Evaluation was performed under the same conditions as the battery with the electrode configuration of NCM811/graphite.

[Ni elution amount measurement]
Evaluation was performed under the same conditions as the battery with the electrode configuration of NCM811/graphite.

Evaluation results are shown in Tables 8 and 9. The values of the capacity retention rate and the Ni elution amount of Examples 2-1 to 2-18 are based on the values of the capacity retention rate and the Ni elution amount of Comparative Examples 2-1 to 2-18, respectively, taken as 100. It is a relative value.

As is clear from the above results, even when the positive electrode is changed to NCA, LiSO ₃ F is not added to any silicon compound having an unsaturated bond represented by general formula (1), as in the case of NCM811. Compared to the system, the system to which 1.00% by mass of LiSO ₃ F was added was confirmed to improve the capacity retention rate and suppress the elution of Ni.

Also, in the same procedure as above, as shown in Tables 10 to 13,
Component (III), component (IV), and other solutes or additive components are added to the reference electrolyte solution 1 or reference electrolyte solution 2 at concentrations shown in Tables 10 to 13, and dissolved by stirring. Thus, each non-aqueous electrolyte was obtained.

Aluminum according to Examples 1-40 to 1-77 and Comparative Examples 1-33 to 1-70 in the same procedure as in Example 1-1 except that the non-aqueous electrolytes described in Tables 10 and 11 were used. A laminate type battery was produced and the same evaluation was performed. The results are shown in Tables 14 and 15. In addition, regarding the examples and comparative examples described in Tables 14 and 15, the capacity retention rate after 400 cycles of the comparative example using the electrolytic solution having the composition that does not contain the component (IV) in each electrolytic solution composition, the Ni It was shown as a relative value when each elution amount was set to 100.

Aluminum according to Examples 2-19 to 2-36 and Comparative Examples 2-19 to 2-36 was produced in the same manner as in Example 2-1 except that the non-aqueous electrolyte solutions described in Tables 12 and 13 were used. A laminate type battery was produced and the same evaluation was performed. The results are shown in Tables 16 and 17. Regarding the examples and comparative examples shown in Tables 16 and 17, the capacity retention rate after 400 cycles of the comparative example using the electrolytic solution having the composition that does not contain the component (IV) in each electrolytic solution composition, the Ni It was shown as a relative value when each elution amount was set to 100.

From the results of Table 14, as the component (IV), instead of LiSO ₃ F, a compound having an O=SF bond represented by the general formula (2), O=P-F represented by the general formula (3) In the case of using a compound having a bond, a compound having a P( ₌ O)F2 bond represented by general formula (4), or a compound represented by general formula (5), a system to which component (IV) is not added By comparison, the system to which 1.00% by mass of component (IV) was added was clearly confirmed to improve the capacity retention rate and suppress Ni elution.

Moreover, from the results in Table 15, the above-mentioned effects were similarly confirmed even when other solutes or additional components were added.

Also, from the results in Tables 16 and 17, the above effects could be confirmed in the same way as in the case of NCM811 even when the positive electrode was changed to NCA.

Also, in the same procedure as above, as shown in Table 18,
The components (III) and (IV) were added to the reference electrolyte solution 1 at concentrations shown in Table 18, and dissolved by stirring to obtain the respective non-aqueous electrolyte solutions.

Aluminum laminate type batteries according to Examples 3-1 to 3-12 were produced in the same manner as in Example 1-1 except that the non-aqueous electrolyte described in Table 18 was used, and the same evaluation was performed. gone. The results are shown in Table 19. The examples in Table 19 are shown as relative values when the capacity retention rate after 400 cycles and the Ni elution amount in Examples 3-12 are set to 100, respectively.

From the results in Table 19,
Compared to Example 3-12 using compound (3-1) as component (IV),
Lithium fluorosulfonate, compounds (2-1) to (2-4), (4-1) to (4-2), (5-1) to (5-4) were used as the component (IV). Examples 3-1 to 3-11 are better,
It was confirmed that either or both of the capacity retention rate after 400 cycles and the Ni elution amount were superior.
From this, as the component (IV), lithium fluorosulfonate, a compound having an O=S—F bond represented by the above general formula (2), and P(=O)F ₂ represented by the above general formula (4) By using at least one compound selected from the group consisting of a compound having a bond and a compound represented by the above general formula (5), the effect of suppressing the capacity retention rate after cycling and the Ni elution can be exhibited in a well-balanced manner.

Also, in the same procedure as above, as shown in Table 20,
The components (III) and (IV) were added to the reference electrolyte solution 1 at concentrations shown in Table 20, and dissolved by stirring to obtain the respective non-aqueous electrolyte solutions.

Aluminum laminate batteries according to Examples 4-1 to 4-28 and Comparative Example 4-1 were produced in the same manner as in Example 1-1, except that the non-aqueous electrolyte solution shown in Table 20 was used. and performed the same evaluation. The results are shown in Table 21. The values of the examples and comparative examples in Table 21 are shown as relative values when the capacity retention rate after 400 cycles of Comparative Example 4-1 is set to 100.

From the results in Table 21,
(III) Compared to Comparative Example 4-1 that does not contain component,
In Examples 4-1 to 4-28 using compounds (1-1) to (1-28) as component (III), improvement in durability (capacity retention rate after 400 cycles) was confirmed.
In the examples using compounds (1-1) to (1-4) and (1-6) to (1-28) in which a in the general formula (1) is 3 or 4, a large amount of 3% or more An improvement in durability (capacity retention rate after 400 cycles) was confirmed.
Among them, compounds (1-1), (1-2), (1-4), (1-10), (1-12), (1-15), (1-22), (1-24) , (1-25), and (1-28), a greater improvement in durability (capacity retention rate after 400 cycles) was confirmed.
Furthermore, among them, in the examples using compounds (1-1), (1-2), (1-12), and (1-15), a particularly large improvement in durability (capacity retention rate after 400 cycles) was achieved. confirmed.

Claims (18)

An electrolytic solution for a non-aqueous electrolyte battery comprising a positive electrode containing at least one oxide containing at least nickel as a positive electrode active material, wherein the nickel content in the metal contained in the positive electrode active material is 30 to 100% by mass. and
(I) a non-aqueous organic solvent,
(II) a solute that is an ionic salt;
(III) at least one selected from the group consisting of compounds represented by general formula (1), and
(IV) Lithium fluorosulfonate, a compound having an O=SF bond represented by the general formula (2), a compound having an O=P-F bond represented by the general formula (3), and a compound represented by the general formula (4) including at least one selected from the group consisting of a compound having a P (=O) F ₂ bond shown and a compound represented by the general formula (5),
An electrolytic solution for a non-aqueous electrolyte battery, wherein the concentration of (IV) is 0.01 to 5.00% by mass with respect to 100% by mass of the total amount of (I) to (IV).
Si(R ¹ ) _a (R ² ) _4-a (1)
[In general formula (1), each R ¹ independently represents a group having a carbon-carbon unsaturated bond.
R ² each independently represents a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an allyl group having 3 to 10 carbon atoms, or an alkynyl group having 2 to 10 carbon atoms. an aryl group having 6 to 15 carbon atoms, an allyloxy group having 3 to 10 carbon atoms, an alkynyloxy group having 2 to 10 carbon atoms, and an aryloxy group having 6 to 15 carbon atoms. group, and these groups may have a fluorine atom and/or an oxygen atom.
a is 2-4. ]
R ³ -S(=O) ₂ -F (2)
[In general formula (2), R ³ is an alkyl group, an alkenyl group, an aryl group, an alkoxy group, or an aryloxy group. ]
R ⁴ -PF(=O)-R ⁵ (3)
[In general formula (3), R ⁴ is an alkoxy group or an aryloxy group, and R ⁵ is OLi (where O represents oxygen and Li represents lithium). ]
R ⁶ -P(=O)F ₂ (4)
[In general formula (4), R ⁶ is an aryl group, an alkoxy group, or an aryloxy group. ]

[In general formula (5), X is an oxygen atom or a methylene group optionally substituted with a halogen atom, and Y is a phosphorus atom or a sulfur atom. n is 0 when Y is a phosphorus atom and 1 when Y is a sulfur atom. R ⁷ and R ⁸ are each independently a halogen atom, an alkyl group optionally substituted by a halogen atom, an alkenyl group, or an aryl group. Note that when Y is a sulfur atom, ^R8 does not exist. ] The electrolytic solution for non-aqueous electrolyte batteries according to claim 1, wherein said ^R1 is an ethenyl group. of said R ² ,
alkyl group selected from methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, 3-pentyl group, and tert-pentyl group; is a group that is
alkoxy group is methoxy group, ethoxy group, butoxy group, tert-butoxy group, propoxy group, isopropoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3-tetrafluoropropoxy group, 1 , 1,1-trifluoroisopropoxy group and 1,1,1,3,3,3-hexafluoroisopropoxy group,
the allyl group is a 2-propenyl group,
the alkynyl group is an ethynyl group,
the aryl group is a group selected from a phenyl group, a methylphenyl group, a tert-butylphenyl group, and a tert-amylphenyl group (hydrogen atoms of each aromatic ring may be substituted with a fluorine atom);
the allyloxy group is a 2-propenyloxy group,
the alkynyloxy group is a propargyloxy group,
the aryloxy group is a group selected from a phenoxy group, a methylphenoxy group, a tert-butylphenoxy group, and a tert-amylphenoxy group (a hydrogen atom of each aromatic ring may be substituted with a fluorine atom); The electrolyte for non-aqueous electrolyte batteries according to claim 1 or 2. 4. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 3, wherein a in the general formula (1) is 3 or 4. The electrolyte solution for non-aqueous electrolyte batteries according to any one of claims 1 to 4, wherein (III) is at least one member selected from the group consisting of the following (1-1) to (1-28).

The (III) is the (1-1), (1-2), (1-3), (1-4), (1-6), (1-7), (1-8), ( 1-10), (1-12), (1-15), (1-22), (1-23), (1-24), (1-25), (1-26), (1- 27), and at least one selected from the group consisting of (1-28). The (III) is the (1-1), (1-2), (1-4), (1-10), (1-12), (1-15), (1-22), ( 1-24), (1-25), and (1-28). of said R ³ ,
the alkyl group is a methyl group, a trifluoromethyl group, an ethyl group, a pentafluoroethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group;
the alkenyl group is an ethenyl group,
The aryl group is a phenyl group, a methylphenyl group, a dimethylphenyl group, a tert-butylphenyl group, a tert-amylphenyl group, a biphenyl group, or a naphthyl group (even if a hydrogen atom in each aromatic ring is substituted with a fluorine atom). good), the electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 7. of the above R ⁴ ,
alkoxy group is methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, tert-butoxy group, 2,2-dimethylpropoxy group, 3-methylbutoxy group, 1-methylbutoxy group, 1 -ethylpropoxy group, 1,1-dimethylpropoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3-tetrafluoropropoxy group, 1,1,1-trifluoroisopropoxy group, 1 , 1,1,3,3,3-hexafluoroisopropoxy group or cyclohexyloxy group,
The aryloxy group is a phenoxy group, methylphenoxy group, dimethylphenoxy group, fluorophenoxy group, tert-butylphenoxy group, tert-amylphenoxy group, biphenoxy group, or naphthoxy group (the hydrogen atom of each aromatic ring is a fluorine atom 9. The electrolytic solution for non-aqueous electrolyte batteries according to any one of claims 1 to 8, which is optionally substituted). of the above R ⁶ ,
The aryl group is a phenyl group, a methylphenyl group, a dimethylphenyl group, a tert-butylphenyl group, a tert-amylphenyl group, a biphenyl group, or a naphthyl group (even if a hydrogen atom in each aromatic ring is substituted with a fluorine atom). good) and
alkoxy group is methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, tert-butoxy group, 2,2-dimethylpropoxy group, 3-methylbutoxy group, 1-methylbutoxy group, 1 -ethylpropoxy group, 1,1-dimethylpropoxy group, 2,2,2-trifluoroethoxy group, 2,2,3,3-tetrafluoropropoxy group, 1,1,1-trifluoroisopropoxy group, 1 , 1,1,3,3,3-hexafluoroisopropoxy group or cyclohexyloxy group,
The aryloxy group is a phenoxy group, methylphenoxy group, dimethylphenoxy group, fluorophenoxy group, tert-butylphenoxy group, tert-amylphenoxy group, biphenoxy group, or naphthoxy group (the hydrogen atom of each aromatic ring is a fluorine atom 10. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 9, which is optionally substituted). of the above R ⁷ and R ⁸ ,
the halogen atom is a fluorine atom, and the alkyl group optionally substituted by the halogen atom is a methyl group, a trifluoromethyl group, an ethyl group, a pentafluoroethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group; can be,
an alkenyl group optionally substituted by a halogen atom is an ethenyl group,
The aryl group optionally substituted by a halogen atom is a phenyl group, a methylphenyl group, a dimethylphenyl group, a tert-butylphenyl group, a tert-amylphenyl group, a biphenyl group, or a naphthyl group (the hydrogen atom of each aromatic ring may be substituted with a fluorine atom). The non-aqueous organic solvent is ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, methyl butyl carbonate, 2,2,2-trifluoroethylmethyl carbonate, 2,2,2-trifluoroethyl ethyl carbonate, 2,2,2-trifluoroethylpropyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, 1,1,1,3,3,3-hexafluoro-1-propylmethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylethyl carbonate, 1,1,1,3,3,3-hexafluoro-1-propylpropyl carbonate, bis(1,1,1, 3,3,3-hexafluoro-1-propyl) carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate, difluoroethylene carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, 2-fluoropropion methyl acid, ethyl 2-fluoropropionate, diethyl ether, dibutyl ether, diisopropyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, furan, tetrahydropyran, 1,3-dioxane, 1,4-dioxane, The at least one selected from the group consisting of N,N-dimethylformamide, acetonitrile, propionitrile, dimethylsulfoxide, sulfolane, γ-butyrolactone, and γ-valerolactone, according to any one of claims 1 to 11. Electrolyte for non-aqueous electrolyte batteries. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 11, wherein said non-aqueous organic solvent contains at least one selected from the group consisting of cyclic carbonates and chain carbonates. The cyclic carbonate is at least one selected from the group consisting of ethylene carbonate, propylene carbonate, and fluoroethylene carbonate, and the chain carbonate is the group consisting of ethyl methyl carbonate, dimethyl carbonate, diethyl carbonate, and methyl propyl carbonate. The electrolytic solution for a non-aqueous electrolytic battery according to claim 13, which is at least one selected from. The solute comprises at least one cation selected from the group consisting of alkali metal ions and alkaline earth metal ions, hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, and bis(trifluoromethane). 15. The electrolyte for non-aqueous electrolyte batteries according to any one of claims 1 to 14, which is an ionic salt paired with at least one anion selected from the group consisting of sulfonyl)imide anions. The cation of the solute is lithium, sodium, potassium, or magnesium, and the anion is selected from the group consisting of hexafluorophosphate anion, tetrafluoroborate anion, trifluoromethanesulfonate anion, and bis(trifluoromethanesulfonyl)imide anion. The electrolytic solution for a non-aqueous electrolyte battery according to claim 15, which is at least one kind. The non-aqueous electrolyte battery according to any one of claims 1 to 16, wherein the concentration of (III) is 0.01 to 2.00% by mass with respect to 100% by mass of the total amount of (I) to (IV). Electrolyte for a positive electrode containing at least one kind of oxide containing at least nickel as a positive electrode active material, wherein the nickel content in the metal contained in the positive electrode active material is 30 to 100% by mass; and a negative electrode; A nonaqueous electrolyte battery comprising the electrolyte for a nonaqueous electrolyte battery according to any one of the above.