JP2011003529A - Binder resin composition for nonaqueous secondary battery, negative electrode for nonaqueous secondary battery, and nonaqueous secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder resin composition for a nonaqueous secondary battery electrode provided with binding property with an electrode active material of a nonaqueous secondary battery, and swelling-resistance to electrolyte liquid and lithium ion conductivity, and thereby to provide the nonaqueous secondary battery excellent in battery performance such as cyclic characteristics, low temperature output, or the like.SOLUTION: The binder resin composition for the nonaqueous secondary battery electrode includes a water dispersion object of a composite polymer (A) of a fluoropolymer (a1) and a polymer (a2) having an oxygenated functional group, and a water dispersion object of a cellulosic polymer (B), and a rubber polymer (C).

Description

  The present invention relates to a binder resin composition for a non-aqueous secondary battery, a negative electrode for a non-aqueous secondary battery and a non-aqueous secondary battery using the same.

In recent years, demand for high-capacity secondary batteries has increased with the downsizing of electronic devices. In particular, lithium ion secondary batteries having higher energy density and excellent large-current charge / discharge characteristics are attracting attention as compared to nickel-cadmium batteries and nickel-hydrogen batteries.
The positive electrode and the negative electrode of the lithium ion secondary battery are each formed by applying a slurry of an active material and a binder resin composition on a current collector. As the binder resin, a cellulose polymer such as carboxymethyl cellulose (CMC), a rubber polymer such as styrene-butadiene rubber (SBR), and a fluorine polymer such as polyvinylidene fluoride (PVDF) are often used. Water-soluble polymers such as CMC have excellent binding properties with active materials, and exhibit good cycle characteristics (capacity retention ratio) due to low swelling in non-aqueous electrolyte solvents such as ethylene carbonate. Ionic conductivity is not sufficient. On the other hand, although an electrophilic polymer such as PVDF is excellent in lithium ion conductivity, it is inferior in binding property and resistance to electrolytic solution swelling.

  In Patent Document 1, as a binder resin, a CMC having polyethylene oxide ether-bonded to locally form a portion having a high lithium ion conductivity, ions between the active material and the electrolytic solution are used. It is described to improve conductivity. However, in this method, the binding property which is a characteristic of CMC is lowered, and as a result, the cycle characteristics as a battery are insufficient.

Patent Document 2 describes an example in which a dispersion of PVDF powder and styrene-butadiene rubber (SBR) is dispersed in water and CMC is added as a binder resin. However, in this method, PVDF is used in a powder form, so that the dispersibility is inferior and it is difficult to maintain the coating stability.
In Patent Document 3, a water-soluble polymer such as polyvinyl alcohol and a fluorine-based polymer such as PVDF are dissolved in a solvent containing N-methyl-2-pyrrolidone (NMP) and used as a binder resin slurry. Are listed.

In Patent Document 4, as a binder resin, a fluorine-based polymer such as PVDF, which is a polymer that easily swells in a non-aqueous electrolyte, and a cellulose-based resin that is a polymer that does not easily swell in a non-aqueous electrolyte include NMP and the like. It is described that, when used by dissolving in an organic solvent, there is no coating unevenness, and the utilization factor of the electrode active material is improved and the electrode characteristics are excellent.
However, in these methods, an organic solvent such as NMP is used as a solvent, and in the mass production accompanying the future increase in demand, the environmental load at the time of coating and drying is very large compared to the case of using an aqueous solvent.

  Patent Document 5 describes that the output characteristics are improved by using an aqueous dispersion of a composite polymer of a fluorine-containing polymer and a functional group-containing polymer as a binder resin. However, in this method, the aqueous dispersion of the composite polymer is inferior in binding force to the aqueous dispersion of rubber polymer such as SBR, and the cycle characteristics are not sufficient.

Japanese Patent No. 3960193 JP 2008-243441 A JP 2004-95332 A JP 2002-93420 A JP-A-10-302799

  As described above, a water-soluble polymer such as CMC is excellent in binding property with an active material and resistance to electrolytic solution swelling, but lithium ion conductivity is not sufficient. On the other hand, a parent electrolyte polymer such as PVDF is Although it is excellent in lithium ion conductivity, it is inferior in binding property and electrolyte solution swelling resistance. Further, when both are used together to satisfy both of these performances simultaneously, it is necessary to use an organic solvent such as NMP because both are incompatible.

  The present invention has been made in view of the background art, and the problem is that it can be uniformly dispersed in water without using an organic solvent such as NMP, and has excellent binding properties (= electrode strength). An object of the present invention is to provide a binder resin composition for a lithium ion secondary battery electrode that has both lithium ion conductivity (= low temperature output).

  As a result of intensive studies in view of the above problems, the present inventors have determined that water-dispersible particles of a composite polymer of a fluorine-based polymer and a polymer having an oxygen-containing functional group can be combined with a cellulose-based polymer and a rubber-based polymer. By dispersing the water-dispersible particles in the mixed binder, it is possible to form a structure that ensures a lithium ion path, and to achieve both binding properties, electrolytic solution swelling resistance, and lithium ion conductivity. As a result, the present invention has been completed.

That is, the gist of the present invention is as follows.
(1) Water dispersion particles of a composite polymer (A) of a fluorine-based polymer (a1) and a polymer (a2) having an oxygen-containing functional group, a cellulose-based polymer (B), and a rubber-based polymer (C The binder resin composition for non-aqueous secondary battery electrodes, comprising water-dispersed particles of
(2) The binder resin composition for a non-aqueous secondary battery electrode according to claim 1, wherein the binder resin composition further contains a conductive additive (D).
(3) The binder resin composition for a nonaqueous secondary battery electrode according to any one of claims 1 and 2, wherein the fluorine-based polymer (a1) is polyvinylidene fluoride or a copolymer thereof.
(4) The oxygen-containing functional group of the polymer (a2) having an oxygen-containing functional group is a hydroxy group, a peroxy group, a carboxyl group, a carbonyl group, an acetyl group, an aldehyde group, a sulfo group, a nitro group, a nitroso group, or an ether bond. The binder resin composition for non-aqueous secondary battery electrodes according to any one of claims 1 to 3, which is at least one selected from an ester bond and an amide bond. (5) The binder resin composition for nonaqueous secondary battery electrodes according to any one of claims 1 to 4, wherein the cellulose polymer (B) is carboxymethylcellulose or a metal salt thereof. (6) The binder resin composition for a nonaqueous secondary battery electrode according to any one of claims 1 to 5, wherein the rubber polymer (C) is a styrene-butadiene rubber.
(7) The binder resin for a non-aqueous secondary battery electrode according to any one of claims 1 to 6, wherein the conductive auxiliary agent (D) is at least one selected from fibrous carbon, graphite particles, and carbon black. Composition.
(8) A negative electrode in which an active material layer containing a binder and a negative electrode active material is formed on a current collector, wherein the binder is the binder resin composition for an electrode according to any one of claims 1 to 7. A negative electrode for a non-aqueous secondary battery, characterized in that there is.
(9) A battery including a positive electrode and a negative electrode capable of inserting and extracting lithium ions, an electrolyte, and an electrolytic solution, wherein the negative electrode is the negative electrode according to claim 8.

  The binder resin composition for a non-aqueous secondary battery electrode of the present invention is excellent in binding property with an active material, resistance to electrolytic solution, and lithium ion conductivity. By using the binder resin, the electrode strength and low temperature can be reduced. A non-aqueous secondary battery excellent in battery characteristics such as output is realized.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. However, the description of constituent elements described below is an example (representative example) of an embodiment of the present invention, and is not specified by these contents.
<Binder resin composition>
The binder resin composition of the present invention comprises an aqueous dispersion particle of a composite polymer (A) of at least a fluorine-based polymer (a1) and a polymer (a2) having an oxygen-containing functional group, and a cellulose-based polymer (B). And water-dispersed particles of rubber polymer (C).

The binder resin composition of the present invention can be used for both positive and negative electrodes. In particular, when the binder of the active material layer constituting the negative electrode is used, the above-described effects of the present invention are remarkably exhibited.
Composite polymer (A)
The composite polymer (A) in the binder resin composition of the present invention is preferably a composite of the fluorine-based polymer (a1) and the polymer (a2) having an oxygen-containing functional group. As used herein, the term “composite” refers to a structure in which a fluorine-based polymer (a1) and a polymer (a2) having an oxygen-containing functional group form an interpenetrating structure (an interpenetrating network structure (hereinafter, IPN structure)). The polymer having a structure in which the polymer (a2) having an oxygen-containing functional group enters between the molecular chains of the fluorine-based polymer (a1). However, the form of the composite is not limited to the IPN structure, and a core-shell structure, a graft polymer, a block copolymer, and the like are conceivable.

  Such water-dispersed particles of the composite polymer (A) are obtained by subjecting the raw material monomer forming the fluorine-based polymer (a1) to emulsion polymerization in the presence of water and an emulsifier to obtain primary particles. It can be produced by polymerizing a raw material monomer that forms a polymer (a2) having an oxygen-containing functional group in the presence. However, the method for producing water-dispersed particles of the composite polymer (A) is not limited to the above method.

Fluorine polymer (a1)
The fluorine polymer in the present invention refers to a polymer having one or more fluorine atoms in a polymerized unit, and examples of the fluorine polymer include vinylidene fluoride (VDF), chlorotrifluoroethylene (CTFE), Examples thereof include homopolymers or copolymers such as tetrafluoroethylene (TFE), hexafluoropropylene (HFP), trifluoroethylene (TrFE), and vinyl fluoride (VF). Among these, the use of PVDF is preferable in terms of high ion conductivity and the amount of movable lithium ions does not decrease.
Among these, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, and vinyl fluoride are preferable, and vinylidene fluoride, hexafluoropropylene, and trifluoroethylene are particularly preferable from the viewpoint of ionic conductivity.

Polymer having oxygen-containing functional group (a2)
In the present invention, the polymer (a2) having an oxygen-containing functional group is a hydroxyl group, a peroxy group, a carboxyl group, a carbonyl group, an acetyl group, an aldehyde group, a sulfo group, a nitro group, a nitroso group, an ether in a polymer unit. A polymer having any of a bond, an ester bond and an amide bond.

Examples of the polymer (a2) having an oxygen-containing functional group include a cellulose polymer, an acrylic polymer, an ether polymer, an alcohol polymer, and an ester polymer.
Examples of the acrylic polymer include polyacrylic acid, polymethacrylic acid, polyalkyl acrylate, and polyalkyl methacrylate.

Examples of the ether polymer include polyethylene oxide, polypropylene oxide, polyphenylene oxide, and polyetherimide.
Examples of the alcohol polymer include polyvinyl alcohol, polybutyl alcohol, and polyalkylene glycol.
Examples of the ester polymer include polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6 naphthalate, and polyarylate.

Among these, acrylic polymers are preferable from the viewpoint of affinity with fluorine polymers, and polyacrylic acid and polymethacrylic acid are particularly preferable from the viewpoint of water dispersibility and binding properties. Polyalkyl acrylates and polyalkyl methacrylates are also particularly preferred from the viewpoint of few side reactions.
The content ratio of the fluorinated polymer (a1) and the polymer (a2) having an oxygen-containing functional group in the composite polymer (A) is high when the total of both is 100% by weight. The lower limit of the content of the molecule (a1) is usually 1 wt%, preferably 10 wt%, more preferably 20 wt%, and the upper limit is usually 99 wt%, preferably 90 wt%, more preferably 80 wt%. % By weight.

When the amount is too large, the uniform dispersibility in the aqueous solvent and the binding property to the active material tend to decrease, and when the amount is too small, the ionic conductivity tends to decrease.
Cellulosic polymer (B)
Examples of the cellulose polymer include methylcellulose, ethylcellulose, acetylcellulose, hydroxyethylcellulose, carboxymethylcellulose, starch, carrageenan, pullulan, guar gum, xanthan gum (xanthan gum), hydroxypropylcellulose, hydroxypropylmethylcellulose and the like.

Among these, hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose are preferable, and hydroxyethyl cellulose, carboxymethyl cellulose, and hydroxypropyl cellulose are particularly preferable from the viewpoint of dispersibility and thickening.
The mixing ratio of the cellulose-based polymer (B) of the present invention to the water-dispersed particles of the composite polymer (A) of the fluorine-based polymer (a1) and the polymer (a2) having an oxygen-containing functional group is as follows: When the total of (A) and (B) is 100% by weight, the lower limit of the content of the composite polymer (A) is usually 1% by weight, preferably 10% by weight, more preferably 20% by weight. The upper limit is usually 99% by weight, preferably 90% by weight, more preferably 80% by weight.

When the amount is too large, the uniform dispersibility in the aqueous solvent and the binding property to the active material tend to decrease, and when the amount is too small, the ionic conductivity tends to decrease.
Rubber polymer (C)
Rubber polymers include natural rubber, styrene / butadiene rubber, isoprene rubber, nitrile rubber, chloroprene rubber, butyl rubber, ethylene / propylene rubber, acrylic rubber, chlorinated polyethylene rubber, fluorine rubber, silicone rubber, urethane rubber, polysulfide. Examples thereof include rubber, styrene / isoprene / styrene rubber, acrylonitrile / butadiene rubber, butadiene rubber, ethylene / propylene / diene copolymer, and styrene / butadiene rubber (SBR) is particularly easily available.

Of these, natural rubber, styrene / butadiene rubber, isoprene rubber, ethylene / propylene rubber, styrene / isoprene / styrene rubber, and acrylonitrile / butadiene rubber are preferable, and natural rubber, styrene / butadiene rubber, and ethylene / propylene rubber are viscoelastic. Is particularly preferred.
For example, in the case of SBR, rubber-based polymer water-dispersed particles can be produced by emulsion polymerization of styrene and butadiene.

  In the present invention, water-dispersed particles of rubber-based polymer (C), and water-dispersed particles of composite polymer (A) of fluorine-based polymer (a1) and polymer having oxygen-containing functional group (a2), The use ratio of (A) and (C) is 100% by weight, and the use amount of the composite polymer (A) is usually 1% by weight, preferably 10% by weight, More preferably, it is 20% by weight, and the upper limit is usually 99% by weight, preferably 90% by weight, and more preferably 80% by weight.

When the amount is too large, the uniform dispersibility in the aqueous solvent and the binding property to the active material tend to decrease, and when the amount is too small, the ionic conductivity tends to decrease.
If desired, a conductive additive (D) may be further added to the binder resin composition. Examples of the conductive assistant include fibrous carbon such as vapor grown carbon fiber (VGCF), carbon nanotube (CNT), carbon nanofiber (CNF), carbon black such as graphite particles, acetylene black, ketjen black, furnace black, Examples thereof include fine powder made of Cu, Ni, Al, Si or alloys thereof having an average particle size of 10 μm or less. The addition amount of the conductive assistant is usually 0.1 to 10% by weight, preferably 0.5 to 5% by weight, based on the negative electrode active material of the present invention.

In the present invention, when the water-dispersed particles of the composite polymer (A) of the above-described fluorine-based polymer (a1) and the polymer (a2) having an oxygen-containing functional group are used as the binder resin composition for an electrode, Both are used as a slurry in which an active material of each electrode, and a conductive material and a thickener used as necessary are dispersed in an aqueous solvent capable of dissolving or dispersing.
Examples of the aqueous solvent in this case include pure water or an alcohol solution containing 1% by mass or more of water, and pure water is preferable in terms of cost.

<Negative electrode>
As in the case of the positive electrode described above, the negative electrode is obtained by forming a negative electrode active material and a negative electrode active material layer containing the binder resin composition of the present invention on a current collector.
As a material of the negative electrode current collector, a metal material such as copper, nickel, stainless steel, nickel-plated steel, or a carbon material such as carbon cloth or carbon paper is used. Examples of the shape include a metal foil, a metal cylinder, a metal coil, a metal plate, and a metal thin film in the case of a metal material, and a carbon plate, a carbon thin film, and a carbon cylinder in the case of a carbon material. Among these, metal thin films are preferable because they are currently used in industrialized products. In addition, you may form a thin film suitably in mesh shape.

The lower limit of the thickness of the current collector is usually 5 μm, preferably 9 μm, and the upper limit is usually 30 μm, preferably 20 μm.
The negative electrode active material layer includes a negative electrode active material. The negative electrode active material is not particularly limited as long as it can electrochemically occlude and release lithium ions, but it can usually occlude and release lithium from the viewpoint of high safety. A carbon material is used.

Although there is no restriction | limiting in particular as a carbon material, Graphite (graphite), such as artificial graphite and natural graphite, and the thermal decomposition thing of organic substance on various thermal decomposition conditions are mentioned. Examples of pyrolysis products of organic matter include coal-based coke, petroleum-based coke, coal-based pitch carbide, petroleum-based pitch carbide, or carbide obtained by oxidizing these pitches, needle coke, pitch coke, phenol resin, crystalline cellulose, etc. And carbon materials obtained by partially graphitizing these, furnace black, acetylene black, pitch-based carbon fibers, and the like. Among them, graphite is preferable, and particularly preferable is artificial graphite, purified natural graphite, or graphite material containing pitch in these graphites, which is manufactured by subjecting easy-graphite pitch obtained from various raw materials to high-temperature heat treatment. Therefore, those subjected to various surface treatments are mainly used. One of these carbon materials may be used alone, or two or more thereof may be used in combination.

When a graphite material is used as the negative electrode active material, the lower limit of the d value (interlayer distance) of the lattice plane (002 plane) determined by X-ray diffraction by the Gakushin method is usually 0.335 nm, and the upper limit is usually 0.34 nm. Preferably, it is 0.337 nm.
Moreover, it is preferable that the ash content of graphite material is 1 mass% or less normally with respect to the mass of graphite material, especially 0.5 mass% or less, especially 0.1 mass% or less.

Further, the crystallite size (Lc) of the graphite material determined by X-ray diffraction by the Gakushin method is usually 30 nm or more, preferably 50 nm or more, and particularly preferably 100 nm or more.
Further, the median diameter of the graphite material obtained by the laser diffraction / scattering method has a lower limit of usually 1 μm, preferably 3 μm, more preferably 5 μm, particularly preferably 7 μm or more, and an upper limit of usually 100 μm, preferably 50 μm, More preferably, it is 40 micrometers, Most preferably, it is 30 micrometers or less.

The lower limit of the BET specific surface area of the graphite material is usually 0.5 m ² / g, preferably 0.7 m ² / g, more preferably 1.0 m ² / g, particularly preferably 1.5 m ² / g or more. by and the upper limit is usually 25.0m ² / g,, preferably 20.0 m ² / g, more preferably 15.0 m ² / g, particularly preferably 10.0 m ² / g.
Further, when performing Raman spectroscopy using argon laser light for graphite material, and strength _{I A} of the peak _{P A} is detected in the range of 1580～1620Cm ^-1, it is detected in the range of 1350 ^-1 that intensity ratio _I a / _{I B} of the intensity _{I B} of a peak _{P B} is what is preferably 0 to 0.5. Further, the half width of the peak _{P A} is preferably 26cm ^-1 or less, 25 cm ^-1 or less is more preferable.

  In addition to the various carbon materials described above, other materials capable of inserting and extracting lithium can be used as the negative electrode active material. Specific examples of the negative electrode active material other than the carbon material include metal oxides such as tin oxide and silicon oxide, sulfides and nitrides, and lithium alloys such as lithium alone and lithium aluminum alloys. As for materials other than these carbon materials, one kind may be used alone, or two or more kinds may be used in combination. Moreover, you may use in combination with the above-mentioned carbon material.

The lower limit of the content ratio of the negative electrode active material in the negative electrode active material layer is usually 70% by weight, preferably 75% by weight, more preferably 80% by weight, and the upper limit is usually 99.99% by weight, preferably 99%. .9% by weight.
In addition to the binder resin composition of the present invention described above, known binders can be arbitrarily selected and used as the binder for binding the negative electrode active material. Examples of this are:
Examples include inorganic compounds such as silicate and water glass, and natural compounds such as polyalginic acid.

The lower limit of the weight average molecular weight of these polymers is usually 1000, preferably 10,000, and the upper limit is usually 3 million, preferably 1 million.
<Method for producing negative electrode>
There is no restriction | limiting in particular about the manufacturing method of the negative electrode in this invention.
For example, a composite polymer (A) obtained by combining a negative electrode active material, a fluorine-based polymer (a1), and a polymer (a2) having an oxygen-containing functional group, a cellulose-based polymer (B), and a rubber-based polymer Examples include a method of producing a negative electrode by dispersing the polymer (C) in a dispersion medium to form a slurry, which is applied to a current collector and dried.

The ratio in which the composite polymer (A), the cellulose polymer (B), and the rubber polymer (C) are mixed with the negative electrode active material will be described below.
The lower limit of the content ratio of the composite polymer (A) to the negative electrode active material is usually 0.01% by weight, preferably 0.05% by weight, more preferably 0.1% by weight, and the upper limit is , Usually 5% by weight, preferably 3% by weight.

If the amount is too large, the cycle characteristics tend to deteriorate. If the amount is too small, the input / output characteristics tend to decrease.
The lower limit of the content ratio of the cellulosic polymer (B) with respect to the negative electrode active material is usually 0.01 wt%, preferably 0.05 wt%, more preferably 0.1 wt%, and the upper limit is , Usually 5% by weight, preferably 3% by weight. If the amount is too large, the input / output characteristics tend to deteriorate, and if the amount is too small, the cycle characteristics tend to decrease.

The lower limit of the content of the rubber-based polymer (C) with respect to the negative electrode active material is usually 0.01% by weight, preferably 0.05% by weight, more preferably 0.1% by weight, and the upper limit is , Usually 5% by weight, preferably 3% by weight. If the amount is too large, the input / output characteristics tend to deteriorate, and if the amount is too small, the cycle characteristics tend to decrease.
If desired, a conductive additive (D) may be further added to the binder resin composition. The lower limit of the content ratio of the conductive agent (D) to the negative electrode active material is usually 0.01% by weight, preferably 0.05% by weight, more preferably 0.1% by weight, and the upper limit is usually 5% by weight, preferably 3% by weight. If the amount is too large, the discharge capacity tends to decrease. If the amount is too small, the cycle characteristics tend to decrease.

As the dispersion medium, an organic solvent such as NMP or an aqueous solvent can be used, but an aqueous solvent having a low environmental load is preferable.
Examples of the dispersion method include an aqueous dispersion of the composite polymer (A), an aqueous solution of the cellulose polymer (B), an aqueous dispersion of the rubber polymer (C), a negative electrode active material, and a conductive auxiliary agent (if desired) Examples thereof include a method in which D) is placed in a container and dispersed using a stirring defoamer, a mixer, a disperser, or the like.

After applying the slurry on the current collector, it is usually 60 ° C. or higher, preferably 80 ° C. or higher, and the upper limit is usually 200 ° C. or lower, preferably 195 ° C. or lower, in dry air or an inert atmosphere. Dry to form an active material layer.
The lower limit of the thickness of the active material layer obtained by applying and drying the slurry is usually 5 μm, preferably 20 μm, more preferably 30 μm, and the upper limit is usually 200 μm, preferably 100 μm, more preferably 75 μm. . If the active material layer is too thin, it may not be practical as a negative electrode due to the balance with the particle size of the active material, and if it is too thick, it may be difficult to obtain a sufficient Li occlusion / release function for high-density current values. is there.

The performance of the negative electrode material produced using the binder resin composition obtained by the above production method is typically as follows.
The low-temperature output is usually 1.01 times or more, preferably 1.05 times or more, as compared with a binder resin composition comprising only an aqueous dispersion of a cellulose polymer (B) and a rubber polymer (C). More preferably, it is 1.10 times or more.

The cycle retention rate is usually 1.01 times or more, preferably 1.10 times or more, compared with the binder resin composition consisting only of the composite polymer (A) and the cellulose polymer (B). Preferably, it is 1.20 times or more.
Furthermore, the performance of the negative electrode material produced by using the binder resin composition obtained by the above production method is characterized by satisfying both the low temperature output performance and the cycle maintenance rate performance at the same time.

<Non-aqueous secondary battery>
The basic configuration of the non-aqueous secondary battery of the present invention, particularly preferably a lithium ion secondary battery is the same as that of a conventionally known lithium ion secondary battery, and usually a positive electrode and a negative electrode capable of inserting and extracting lithium ions, As well as an electrolyte. The binder resin composition of the present invention described above can be used as a binder for any active material layer of the positive electrode and the negative electrode, but may be used for only one of them.

<Positive electrode>
The positive electrode is obtained by forming a positive electrode active material layer containing a positive electrode active material and a binder on a current collector.
The positive electrode active material layer is usually formed by mixing a positive electrode material, a binder, and a conductive material and a thickener, which are used if necessary, in a dry form into a sheet shape, and then pressing the positive electrode current collector on the positive electrode current collector. Alternatively, these materials are dissolved or dispersed in a liquid medium to form a slurry, which is applied to the positive electrode current collector and dried.

  As the material for the positive electrode current collector, metal materials such as aluminum, stainless steel, nickel plating, titanium, and tantalum, and carbon materials such as carbon cloth and carbon paper are usually used. Of these, metal materials are preferable, and aluminum is particularly preferable. As for the shape, in the case of a metal material, a metal foil, a metal cylinder, a metal coil, a metal plate, a metal thin film, an expanded metal, a punch metal, a foam metal, etc., and in the case of a carbon material, a carbon plate, a carbon thin film, a carbon cylinder Etc. Among these, metal thin films are preferable because they are currently used in industrialized products. In addition, you may form a thin film suitably in mesh shape.

  When a thin film is used as the positive electrode current collector, the thickness is arbitrary, but the lower limit is usually 1 μm, preferably 3 μm, more preferably 5 μm, and the upper limit is usually 100 mm, preferably 1 mm, more preferably 50 μm. A range is preferred. If the thickness is less than the above range, the strength required for the current collector may be insufficient. On the other hand, if it is thicker than the above range, the handleability may be impaired.

Examples of the positive electrode active material include metal chalcogen compounds that can occlude and release alkali metal cations such as lithium ions during charge and discharge. Examples of metal chalcogen compounds include vanadium oxide, molybdenum oxide, manganese oxide, chromium oxide, titanium oxide, tungsten oxide and other transition metal oxides, vanadium sulfide, molybdenum sulfide. , Transition metal sulfides such as titanium sulfide, transition metal sulfides such as NiS ₃ and FePS ₃ , selenium compounds of transition metals such as VSe ₂ and NbSe ₃ , Fe _0.25 V _0. Examples thereof include composite oxides of transition metals such as ₇₅ S ₂ and Na _0.1 CrS ₂ and composite sulfides of transition metals such as LiCoS ₂ and LiNiS ₂ .

Among _{these, V 2 O 5, V 5} O 13, VO 2, Cr 2 O 5, MnO 2, TiO, MoV 2 O 8, LiCoO 2, LiNiO 2, LiMn 2 O 4, TiS 2, V 2 S 5 Cr _0.25 V _0.75 S ₂ , Cr _0.5 V _0.5 S _{2 and the} like are preferable, and LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ and a part of these transition metals are particularly preferable. It is a lithium transition metal composite oxide substituted with another metal. These positive electrode active materials may be used alone or in combination.

The lower limit of the content ratio of the positive electrode active material in the positive electrode active material layer is usually 10% by mass, preferably 30% by mass, more preferably 50% by mass, and the upper limit is usually 99.9% by mass, preferably 99%. % By mass.
As the binder for binding the positive electrode active material, in addition to the binder resin composition of the present invention described above, a known one can be arbitrarily selected and used. Examples of such include inorganic compounds such as silicate and water glass, Teflon (registered trademark), and polymers having no unsaturated bond. The lower limit of the weight average molecular weight of these polymers is usually 10,000, preferably 100,000, and the upper limit is usually 3 million, preferably 1 million.

  The lower limit of the ratio of the binder in the positive electrode active material layer is usually 0.1% by mass, preferably 1% by mass, more preferably 5% by mass, and the upper limit is usually 80% by mass, preferably 60% by mass. More preferably, it is 40% by mass, and most preferably 10% by mass. If the proportion of the binder is too low, the positive electrode active material cannot be sufficiently retained, and the mechanical strength of the positive electrode may be insufficient, and the battery performance such as cycle characteristics may be deteriorated. There is a possibility that it may lead to a decrease in capacity and conductivity.

The positive electrode active material layer may contain a conductive material in order to improve the conductivity of the electrode. The conductive agent is not particularly limited as long as it can be mixed with an active material in an appropriate amount to impart conductivity, but is usually carbon powder such as acetylene black, carbon black, and graphite, various metal fibers, powder, and foil. Etc.
As a liquid medium for forming a slurry, it is possible to dissolve or disperse lithium nickel manganese cobalt based composite oxide powder, which is a positive electrode material, a binder, and a conductive material and a thickener used as necessary. The solvent is not particularly limited as long as it is a suitable solvent, and either an aqueous solvent or an organic solvent may be used. Examples of the aqueous solvent include water and alcohol. Examples of the organic solvent include N-methylpyrrolidone (NMP), dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, N -N-dimethylaminopropylamine, ethylene oxide, tetrahydrofuran (THF), toluene, acetone, dimethyl ether, dimethylacetamide, hexamethylphosphamide, dimethyl sulfoxide, benzene, xylene, quinoline, pyridine, methylnaphthalene, hexane, etc. be able to. In particular, when an aqueous solvent is used, a dispersant is added together with the thickener, and a slurry such as SBR is slurried. In addition, these solvents may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

The thickness of the positive electrode active material layer is usually about 10 to 200 μm.
The positive electrode active material layer obtained by applying the slurry to the positive electrode current collector and drying is preferably consolidated by a roller press or the like in order to increase the packing density of the positive electrode active material.
<Electrolyte>
As the electrolyte, a non-aqueous electrolyte obtained by dissolving a lithium salt in a non-aqueous solvent, or a gel, rubber, or solid sheet obtained by using an organic polymer compound or the like from the non-aqueous electrolyte is used.

The non-aqueous solvent used in the non-aqueous electrolyte is not particularly limited, and can be appropriately selected from known non-aqueous solvents that have been conventionally proposed as solvents for non-aqueous electrolytes. For example, chain carbonates such as diethyl carbonate, dimethyl carbonate, and ethyl methyl carbonate; cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate; chain ethers such as 1,2-dimethoxyethane; tetrahydrofuran, 2-methyl Cyclic ethers such as tetrahydrofuran, sulfolane and 1,3-dioxolane; chain esters such as methyl formate, methyl acetate and methyl propionate; γ-
And cyclic esters such as butyrolactone and γ-valerolactone. Any one of these non-aqueous solvents may be used alone, or two or more thereof may be mixed and used, but a combination of a mixed solvent containing a cyclic carbonate and a chain carbonate is preferred.

<Lithium salt>
The lithium salt used in the non-aqueous electrolytic solution is not particularly limited, and can be appropriately selected from known lithium salts that can be used for this purpose. For example, halides such as LiCl and LiBr, perhalogenates such as LiClO ₄ , LiBrO ₄ and LiClO ₄ , inorganic fluoride salts such as LiPF ₆ , LiBF ₄ and LiAsF ₆ , lithium bis (oxalatoborate) LiBC ₄ O Inorganic lithium salt such as ₈ , LiCF ₃ SO ₃ , LiC
Examples thereof include perfluoroalkane sulfonates such as ₄ F ₉ SO ₃ and fluorine-containing organic lithium salts such as perfluoroalkane sulfonic acid imide salts such as Li trifluorosulfonimide ((CF ₃ SO ₂ ) ₂ NLi). Lithium salts may be used alone or in combination of two or more. The concentration of the lithium salt in the non-aqueous electrolyte is usually in the range of 0.5M to 2.0M.

  In addition, when an organic polymer compound is included in the above non-aqueous electrolyte and used in the form of a gel, rubber, or solid sheet, specific examples of the organic polymer compound include polyethylene oxide and polypropylene oxide. Polyether polymer compounds; Cross-linked polymers of polyether polymer compounds; Vinyl alcohol polymer compounds such as polyvinyl alcohol and polyvinyl butyral; Insolubilized vinyl alcohol polymer compounds; Polyepichlorohydrin; Polyphosphazene; Siloxane; vinyl polymer compounds such as polyvinylpyrrolidone, polyvinylidene carbonate, polyacrylonitrile; poly (ω-methoxyoligooxyethylene methacrylate), poly (ω-methoxyoligooxyethylene methacrylate-co-methyl methacrylate) Rate) and polymer copolymers such as poly (hexafluoropropylene-vinylidene fluoride).

  The non-aqueous electrolyte solution described above may further contain a film forming agent. Specific examples of the film forming agent include vinylene carbonate, vinyl ethylene carbonate, vinyl ethyl carbonate, methyl phenyl carbonate, carbonate compounds such as fluoroethylene carbonate and difluoroethylene carbonate, alkene sulfides such as ethylene sulfide and propylene sulfide; 1,3- Examples thereof include sultone compounds such as propane sultone and 1,4-butane sultone; acid anhydrides such as maleic anhydride and succinic anhydride.

Moreover, when using a film forming agent, the content is usually 10% by mass or less, particularly 8% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less. When the content of the film forming agent is too large, other battery characteristics such as an increase in initial irreversible capacity, low temperature characteristics, and deterioration in rate characteristics may be adversely affected.
Further, as the electrolyte, a polymer solid electrolyte which is a conductor of an alkali metal cation such as lithium ion can be used. Examples of the polymer solid electrolyte include a polymer in which a salt of Li is dissolved in the aforementioned polyether polymer compound, and a polymer in which the terminal hydroxyl group of the polyether is substituted with an alkoxide.

<Separator>
In order to prevent a short circuit between the electrodes, a porous separator such as a porous film or a nonwoven fabric is usually interposed between the positive electrode and the negative electrode. In this case, the nonaqueous electrolytic solution is used by impregnating a porous separator. As a material for the separator, polyolefin such as polyethylene and polypropylene, polyethersulfone, and the like are used, and polyolefin is preferable.

  The form of the lithium ion secondary battery of the present invention is not particularly limited. Examples include a cylinder type in which a sheet electrode and a separator are spiral, a cylinder type having an inside-out structure in which a pellet electrode and a separator are combined, a coin type in which a pellet electrode and a separator are stacked, and the like. In addition, by storing batteries of these forms in an optional outer case, the battery can be used in an arbitrary shape such as a coin shape, a cylindrical shape, or a square shape.

  The procedure for assembling the lithium ion secondary battery of the present invention is not particularly limited, and may be assembled by an appropriate procedure according to the structure of the battery. For example, the negative electrode is placed on the outer case, and the electrolytic solution is placed thereon. A separator is provided, and a positive electrode is placed so as to face the negative electrode, and it is caulked together with a gasket and a sealing plate to form a battery.

EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.
In addition, manufacture of the negative electrode active material in an Example and a comparative example, preparation of a positive electrode, preparation of the battery for performance evaluation, the measurement of a low temperature output, and the measurement of a cycle maintenance factor were performed by the following method.
(Manufacture of negative electrode active material)
Naturally produced graphite with a 002 plane spacing (d002) by X-ray wide angle diffraction method of 3.36 mm, Lc of 1000 mm or more, tap density of 0.46 g / cm ³ , and 1580 cm ⁻¹ in an argon ion laser Raman spectrum. A scale-like graphite particle having a Raman R value which is a peak intensity ratio in the vicinity of 1360 cm ^{−1 to} a peak intensity in the vicinity of 0.13, an average particle diameter of 28.7 μm and a true density of 2.27 g / cm ³ is Damage to the graphite particle surface by continuously processing the scaly graphite particles at a processing speed of 20 kg / hr under conditions of a rotor peripheral speed of 60 m / second and 10 minutes using a machine system manufactured by Kikai Seisakusho. The spheronization treatment was performed while fine powder was removed by further classification treatment. The obtained spheroidized graphitic carbon has an 002 plane spacing (d002) of 3.36 mm, an Lc of 1000 mm or more, a tap density of 0.83 g / cm ³ by an X-ray wide angle diffraction method, and an argon ion laser Raman spectrum. 1580 cm ^-1 Raman R value is the peak intensity ratio in the vicinity of 1360 cm ^-1 to the peak intensity near 0.24, an average particle diameter of 11.6, BET method specific surface area of 7.7 m ² / g, a true density of 2.27 g / cm ³ and the average circularity was 0.909.

Next, 100 parts by weight of this spheroidized graphitic carbon and 9.4 parts by weight of coal-derived pitch were mixed by heating at 160 ° C. in a compounding machine, then fired to 1000 ° C. in a non-oxidizing atmosphere over 2 weeks, and then room temperature. The mixture was further cooled to pulverize and classified to obtain a multi-layer structure spheroidized carbon material. This multi-layered spheroidized carbon material has an 002 plane spacing (d002) of 3.36 mm by L-ray wide angle diffraction method, Lc of 1000 mm or more, a tap density of 0.98 g / cm ³ , and 1580 cm in an argon ion laser Raman spectrum. ^The Raman R value, which is the peak intensity ratio near 1360 cm ^{−1 to} the peak intensity near ⁻¹ , is 0.31, the average particle size is 11.6 μm, the d10 particle size is 7.6 μm, the d90 particle size is 17.5 μm, and the BET specific surface area Is 3.5m ² / g, coverage is 5.0%
Thus, the pore volume when the ratio 3R / 2H of the rhombohedral 3R to the hexagonal crystal 2H by the X-ray wide angle diffraction method was 0.26 and 10 nm to 100,000 nm was 0.74 ml / g. In addition, the used coal-derived pitch was baked to 1300 ° C. alone in a nitrogen atmosphere, then cooled to room temperature, and pulverized to obtain a 002 plane by X-ray wide angle diffraction of an amorphous carbon single material. Spacing (d002
) Was 3.45 cm and Lc was 24 cm.

(Preparation of positive electrode)
41.7 parts by weight of an N-methylpyrrolidone solution (polyvinylidene fluoride concentration: 12% by weight) in which 10 parts by weight of carbon black and polyvinylidene fluoride are dissolved in 85 parts by weight of lithium nickel manganese cobalt based composite oxide powder And an appropriate amount of N-methylpyrrolidone were added and kneaded to prepare a slurry. This slurry was applied to an aluminum foil with a basis weight of 8.8 mg / cm ² by the doctor blade method. The film was dried at 110 ° C. and further consolidated by a roll press so that the positive electrode layer had a density of 2.45 g / cm 3. This was cut into a 30 mm × 40 mm square and dried at 140 ° C. to obtain a positive electrode.

(Production of battery for performance evaluation)
The positive electrode described above and the negative electrode described in Examples and Comparative Examples were stacked through a separator impregnated with an electrolytic solution to prepare a battery for a charge / discharge test. As the electrolytic solution, a solution obtained by dissolving LiPF6 in a mixed solution of ethylene carbonate: dimethyl carbonate: ethyl methyl carbonate = 3: 3: 4 (weight ratio) to 1 mol / liter was used.

The battery is first charged to 4.1V at 0.2C, further charged to 4.1mA at 4.1V, discharged to 3.0V at 0.2C, and then 4.2V at 0.2C. After further charging to 4.2 mA at 4.2 V, discharging was repeated twice to 3.0 V at 0.2 C for initial adjustment.
(Measurement of low temperature output)
The battery was charged for 150 minutes at a constant current of 0.2C in a 25 ° C environment, and then stored in a thermostatic bath at -30 ° C for 3 hours or more, and then 0.25C, 0.50C, 0.75C, 1.00, respectively. , 1.25 C, 1.50 C, 1.75, and 2.00 C for 2 seconds, and the voltage at the second second was measured. The area of the triangle surrounded by the current-voltage line and the lower limit voltage (3 V) was defined as output (W).

(Measurement of cycle maintenance rate)
The battery prepared as described above was first charged to 0.2 V at 0.2 C, further charged to 4.2 mA at 4.2 V, and then precharged / discharged to 3.0 V at 0.2 C. Next, the battery was charged to 0.7 V at 0.7 C, charged to 4.2 mA at 4.2 V, and then subjected to 300 cycles of charge / discharge to discharge to 3.0 V at 1 C. The ratio of the discharge capacity at the 300th time to the discharge capacity at the first time was determined, and this was used as the cycle retention rate.

Example 1
10 g of negative electrode active material, 10 g of an aqueous solution of carboxymethylcellulose (carboxymethylcellulose concentration: 1% by weight), and an aqueous dispersion of styrene-butadiene rubber (unsaturation: 75%, weight average molecular weight: 120,000) Concentration of butadiene rubber: 50% by weight (0.12 g) and PVDF and polymethyl methacrylate (PMMA) in a composite polymer in which an IPN structure is dispersed in water (concentration 50% by weight, PVDF: PMMA ( Molar ratio) =
70:30) 0.08 g was mixed using a high speed mixer to form a slurry. This slurry was applied onto a copper foil (current collector) by a doctor blade method and dried. This was pressed at a linear density of 20 to 300 kg / cm by a roll press to form an active material layer. The mass of the active material layer after drying was 10 mg / cm ² , the density was 1.6 g / cm ³ , and the average electrode thickness was 68 μm. The negative electrode (negative electrode for a lithium ion secondary battery) produced by the above procedure is used as the negative electrode of Example 1. The obtained negative electrode had a low-temperature output of 0.097 W and a cycle retention rate of 80%. The low-temperature output ratio for Comparative Example 1 was 1.15, and the cycle retention ratio for Comparative Example 2 was 1.33.

Example 2
10 g of negative electrode active material, 10 g of an aqueous solution of carboxymethylcellulose (carboxymethylcellulose concentration: 1% by weight), and an aqueous dispersion of styrene-butadiene rubber (unsaturation: 75%, weight average molecular weight: 120,000) 0.04 g of butadiene rubber (concentration: 50% by weight) and an emulsion in which a composite polymer in which PVDF and PMMA formed an IPN structure is dispersed in water (concentration: 50% by weight, PVDF: PMMA (molar ratio)) = 70: 30) 0.16g was mixed using the high speed mixer, and it was set as the slurry. This slurry was applied onto a copper foil (current collector) by a doctor blade method and dried. This was pressed at a linear density of 20 to 300 kg / cm by a roll press to form an active material layer. The mass of the active material layer after drying was 10 mg / cm ² , the density was 1.6 g / cm ³ , and the average electrode thickness was 68 μm. The negative electrode (negative electrode for lithium ion secondary battery) produced by the above procedure is used as the negative electrode of Example 2. The obtained negative electrode had a low-temperature output of 0.098 W and a cycle retention rate of 85%. The low-temperature output ratio with respect to Comparative Example 1 was 1.17, and the cycle retention ratio with respect to Comparative Example 2 was 1.42.

Example 3
10 g of negative electrode active material, 10 g of an aqueous solution of carboxymethylcellulose (carboxymethylcellulose concentration: 1% by weight), and an aqueous dispersion of styrene-butadiene rubber (unsaturation: 75%, weight average molecular weight: 120,000) 0.04 g of butadiene rubber (concentration: 50% by weight) and an emulsion in which a composite polymer in which PVDF and PMMA formed an IPN structure is dispersed in water (concentration: 50% by weight, PVDF: PMMA (molar ratio)) = 70: 30) 0.16 g and 0.2 g of vapor grown carbon fiber (VGCF) were mixed using a high speed mixer to form a slurry. This slurry was applied onto a copper foil (current collector) by a doctor blade method and dried. This was pressed at a linear density of 20 to 300 kg / cm by a roll press to form an active material layer. The mass of the active material layer after drying is 10 mg / cm ² , the density is 1.6 g / cm ³ ,
The average electrode thickness was 68 μm. The negative electrode (a negative electrode for a lithium ion secondary battery) produced by the above procedure is used as the negative electrode of Example 3. The obtained negative electrode had a low-temperature output of 0.097 W and a cycle retention rate of 90%. The low-temperature output ratio with respect to Comparative Example 1 was 1.16, and the cycle maintenance ratio with respect to Comparative Example 2 was 1.50.

Comparative Example 1
10 g of negative electrode active material, 10 g of an aqueous solution of carboxymethylcellulose (carboxymethylcellulose concentration: 1% by mass), and an aqueous dispersion of styrene / butadiene rubber (unsaturation: 75%, weight average molecular weight: 120,000) 0.2 g of butadiene rubber (concentration: 50% by mass) was mixed using a high speed mixer to form a slurry. This slurry was applied onto a copper foil (current collector) by a doctor blade method and dried. This was pressed at a linear density of 20 to 300 kg / cm by a roll press to form an active material layer. The dried active material layer had a mass of 10 mg / cm ² , a density of 1.6 g / cm ³ , and an average electrode thickness of 68 μm. The negative electrode (negative electrode for lithium ion secondary battery) produced by the above procedure is used as the negative electrode of Comparative Example 1. The obtained negative electrode had a low-temperature output of 0.084 W and a cycle retention rate of 80%. The cycle maintenance ratio with respect to Comparative Example 2 was 1.33.

Comparative Example 2
10 g of negative electrode active material, 10 g of an aqueous solution of carboxymethylcellulose (carboxymethylcellulose concentration: 1% by weight), and an emulsion in which a composite polymer in which PVDF and polymethyl methacrylate (PMMA) form an IPN structure is dispersed in water (Concentration 50 wt%, PVDF
: PMMA (molar ratio) = 70: 30) 0.2 g was mixed using a high-speed mixer to obtain a slurry. This slurry was applied onto a copper foil (current collector) by a doctor blade method and dried. This was pressed at a linear density of 20 to 300 kg / cm by a roll press to form an active material layer. The mass of the active material layer after drying was 10 mg / cm ² , the density was 1.6 g / cm ³ , and the average electrode thickness was 68 μm. The negative electrode (negative electrode for lithium ion secondary battery) produced by the above procedure is used as the negative electrode of Comparative Example 2. The obtained negative electrode had a low-temperature output of 0.097 W and a cycle retention rate of 60%. In addition, the low-temperature output ratio with respect to the comparative example 1 was 1.15.

Comparative Example 3
10 g of the negative electrode active material and 5 g of PVDF (concentration 12%) dissolved in N-methylpyrrolidone were mixed using a high speed mixer to form a slurry. This slurry was applied onto a copper foil (current collector) by a doctor blade method and dried. This was pressed at a linear density of 20 to 300 kg / cm by a roll press to form an active material layer. The dried active material layer had a mass of 10 mg / cm ² , a density of 1.6 g / cm ³ , and an average electrode thickness of 68 μm. The negative electrode (negative electrode for lithium ion secondary battery) produced by the above procedure is used as the negative electrode of Comparative Example 3. The obtained negative electrode had a low-temperature output of 0.120 W and a cycle retention rate of 10%. The low-temperature output ratio with respect to Comparative Example 1 was 1.43, and the cycle maintenance ratio with respect to Comparative Example 2 was 0.167.

From the results in Table 1, the following is clear.
When Example 1 and Examples 2 and 3 are compared with Comparative Example 1, it can be seen that they are excellent in low-temperature output. Moreover, when Example 1 and Example 2, 3 are compared with the comparative example 2 and the comparative example 3, it turns out that it is excellent in cycling characteristics. Therefore, it can be said that only the binder resin composition for a lithium ion secondary battery electrode of the present invention achieves both low temperature output and cycle characteristics at a high level.

  The binder resin composition for a lithium ion secondary battery electrode of the present invention is sufficient with a hydrophilic polymer excellent in binding property to an active material and resistance to electrolytic solution swelling without using an organic solvent such as NMP. Lithium ion secondary polymer with lithium ion conductivity is uniformly dispersed in water, and by using this binder resin composition, the lithium ion secondary has excellent battery characteristics such as cycle characteristics and low-temperature output. A battery is realized.

Claims (9)

  A composite polymer (A) of a fluorine-based polymer (a1) and a polymer (a2) having an oxygen-containing functional group, a cellulose-based polymer (B), and a rubber-based polymer (C); A binder resin composition for non-aqueous secondary battery electrodes.   The binder resin composition for a non-aqueous secondary battery electrode according to claim 1, wherein the binder resin composition further contains a conductive additive (D).   The binder resin composition for non-aqueous secondary battery electrodes according to any one of claims 1 and 2, wherein the fluorine-based polymer (a1) is polyvinylidene fluoride or a copolymer thereof.   The oxygen-containing functional group of the polymer (a2) having an oxygen-containing functional group is a hydroxy group, a peroxy group, a carboxyl group, a carbonyl group, an acetyl group, an aldehyde group, a sulfo group, a nitro group, a nitroso group, an ether bond, or an ester bond. The binder resin composition for nonaqueous secondary battery electrodes according to any one of claims 1 to 3, which is at least one selected from amide bonds.   The binder resin composition for non-aqueous secondary battery electrodes according to any one of claims 1 to 4, wherein the cellulose polymer (B) is carboxymethyl cellulose or a metal salt thereof. The binder resin composition for non-aqueous secondary battery electrodes according to any one of claims 1 to 5, wherein the rubber polymer (C) is styrene-butadiene rubber. The binder resin composition for a non-aqueous secondary battery electrode according to any one of claims 1 to 6, wherein the conductive auxiliary agent (D) is at least one selected from fibrous carbon, graphite on a flake, and carbon black.   It is the negative electrode which formed the active material layer containing a binder and a negative electrode active material on the electrical power collector, Comprising: This binder is a binder resin composition for electrodes in any one of Claims 1-7. A negative electrode for a non-aqueous secondary battery.   A battery comprising a positive electrode and a negative electrode capable of inserting and extracting lithium ions, an electrolyte, and an electrolyte solution, wherein the negative electrode is the negative electrode according to claim 8.