JP2000256616A - Non-aqueous solvent type binder composition, electrode formed therewith, and non-aqueous solvent type secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-aq. electrolyte secondary battery with improved charging/discharging cycle lifetime properties and safety. SOLUTION: This non-aq. electrolyte secondary battery has an electrode with a non-aq. solvent type binder compsn. layer formed by coating the surface of an electrode base with the binder compsn. obtd. by dissolving and/or dispersing a binder resin in a non-aq. solvent followed by elimination of the non-aq. solvent. The binder resin is obtd. by reacting a polyamide resin intermediate (A), an epoxy resin (B), and a polyoxyalkylene monoamine (C), and has the component (C) group at its side chain. The polyamide resin intermediate (A) is obtd. by reacting a diisocyanate or a diamine (a) with a dicarboxylic acid and/or a tricarboxylic acid anhydride (b) in an org. solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous solvent-based binder composition for a battery, which has a small capacity reduction by suppressing the peeling and falling off of an active material even after repeated charging and discharging. More particularly, the present invention relates to a binder composition for a non-aqueous solvent secondary battery, an electrode formed with the composition, and a non-aqueous solvent secondary battery.

2. Description of the Related Art With the advance of electronic technology, the performance of electronic equipment has been improved, miniaturization and portability have been advanced, and batteries with high energy density as power sources have been desired. Conventional secondary batteries include lead-acid batteries, nickel batteries, and cadmium batteries, but they are still insufficient in obtaining batteries with high energy density. Therefore, as a substitute for these batteries, a high energy density organic electrolyte secondary battery (hereinafter referred to as a lithium secondary battery) has been developed and rapidly spread. Lithium secondary batteries use a lithium composite metal oxide such as a lithium cobalt composite oxide for the positive electrode, and a carbon material that can store and release lithium and has excellent flexibility and a low risk of lithium deposition for the negative electrode. A slurry obtained by dispersing these and a binder resin in N-methyl-2-pyrrolidone (NMP) was applied on both sides of a metal foil as a current collector, and after drying the solvent, compression molding was performed by a roller press. Positive and negative electrode plates are obtained. As a binder, polyvinylidene fluoride (PVDF) is mainly used in many cases. However, when polyvinylidene fluoride is used as a binder, the adhesion at the interface between the current collector and the mixture layer, and the adhesion between the mixture layers are inferior, such as in the electrode plate cutting step and the winding step. At the time of the manufacturing process, a part of the mixture peels off and falls off from the current collector, causing a minute short circuit or a variation in battery capacity. In addition, since the carbon material of the negative electrode expands and contracts due to repetition of charge and discharge, the mixture may peel off or fall off from the current collector, or the adhesion between the mixture may decrease, thereby lowering the current collection efficiency. In addition, there is a problem that the battery capacity gradually decreases due to non-uniform reaction with lithium and the like. Further, as described in JP-A-6-172452,
When a vinylidene fluoride-based monomer and a vinylidene fluoride-based copolymer obtained by copolymerizing an unsaturated dibasic monoester as a binder are used as a binder, the adhesion strength with the current collector is Despite the improvement, abnormal temperature rise under high voltage decomposes to generate hydrogen fluoride, which reacts with the lithium intercalation compound (GIC) on the negative electrode plate surface and the deposited lithium metal, generates abnormal heat, and ruptures the battery. ， I could explode.
As a binder other than a fluororesin such as polyvinylidene fluoride, for example, styrene-butadiene rubber (SBR) -based synthetic rubber described in JP-A-5-74461,
Use of synthetic rubbers containing diene rubbers described in JP-A-9-87571, and thermoplastic resins such as polyimide resins described in JP-A-6-16331 have been proposed. However, these dissolve or largely swell in the electrolytic solution, and cannot maintain the adhesion at the interface between the current collector and the mixture layer and the adhesion between the mixture layers for a long time. In addition, when a polyimide resin is used for the mixture layer, the flexibility is low, and when the produced electrode is wound, the mixture layer is cracked or peeled off to reduce the capacity. Diene-based synthetic rubbers such as styrene-butadiene rubber have electrolytic solution resistance,
It is very difficult to uniformly disperse the active material and the binder, etc.
Cellulose, a surfactant, and the like need to be added, and these dissolve in the electrolytic solution to lower the charge / discharge efficiency of the battery.

SUMMARY OF THE INVENTION An object of the present invention is to improve the adhesion at the interface between the current collector and the mixture layer and the adhesion between the mixture layers, thereby suppressing minute short circuits and variations in battery capacity. At the same time, by increasing the capacity of the battery by reducing the amount of binder added, the battery capacity is reduced due to charge / discharge cycles, and the risk of rupture and explosion is reduced even if the battery temperature rises abnormally. To provide a nonaqueous electrolyte secondary battery.

The gist of the present invention to achieve the above object is as known. [1] A polyamide resin intermediate (A), an epoxy resin (B) and a polyoxy resin obtained by reacting a diisocyanate or a diamine (a) with a dicarboxylic acid and / or a tricarboxylic anhydride (b) in an organic solvent. A non-aqueous solvent-based binder composition, comprising: dissolving and / or dispersing a binder resin having a component (C) residue in a side chain obtained by reacting the alkylene monoamine (C) with a non-aqueous solvent. [2] The non-aqueous solvent-based binder composition containing a polyfunctional compound and / or a thermoplastic resin. [3] An electrode, wherein the non-aqueous solvent-based binder composition is prepared by mixing the non-aqueous solvent-based binder composition with an active material, coating the mixture on an electrode substrate surface, and removing the non-aqueous solvent. [4] The electrode as described above, wherein the active material is capable of reversibly inserting and releasing lithium ions by charging and discharging. [5] The active material, reversibly inserting lithium ions by charging and discharging, a transition metal oxide capable of releasing, the transition metal oxide is formula Li _x Mn _y O _{0 (x} is 0.2 ≦ x ≦ 2.
5 wherein y is 0.8 ≦ y ≦ 1.25.) [6] At least one pole of the non-aqueous solvent secondary battery,
A non-aqueous solvent-based secondary battery using the electrode.

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide resin intermediate (A) is not particularly limited, but the carboxyl group in the diisocyanate or diamine (a) and the dicarboxylic acid and / or tricarboxylic anhydride (b) component is 1 equivalent. /
Those obtained by reacting at a ratio such that the isocyanate group or amino group in the component (A) is less than 1 equivalent are exemplified. These components (A) are used alone or in combination of two or more. Although any of the above-mentioned diisocyanates or diamines may be used, diisocyanates are more preferable in view of easiness of production of the component (A), improvement in yield, and the like. The diisocyanate is, for example, aromatic diisocyanate such as 4,4′-diphenylmethane diisocyanate, 2,6-tolylene diisocyanate, 2,4-
Tolylene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, 4,4'-diphenyl ether diisocyanate, m-xylylene diisocyanate, m-
Examples include tetramethylxylylene diisocyanate. Examples of the aliphatic diisocyanate include 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Alicyclic diisocyanate (isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hydrogenated 4,4'-diphenylmethane diisocyanate), transcyclohexane-1,4-diisocyanate, hydrogenated m-xylylene diisocyanate, etc.), complex Cyclic diisocyanate (3,9-bis (3
-Isocyanatopropyl) -2,4,8,10-tetraspiro [5,5] undecane and the like. Among these, aromatic diisocyanates are preferred in terms of improving heat resistance and the like. Examples of the diamine include aliphatic diamine (alkylenediamine, diaminopolydimethylsiloxane, polyoxyalkylenediamine, etc.), alicyclic diamine (isophorone diamine, 4,4′-dicyclohexylmethanediamine, etc.), and heterocyclic diamine. (3,
9-bis (3-aminopropyl) -2,4,8,10-tetraspiro [5,5] undecane, etc., aromatic diamines (p-phenylenediamine, m-phenylenediamine,
p-xylylenediamine, m-xylylenediamine,
4,4'- (or 3,4'-, 3,3'-, 2,4'-, 2,
2'-) diaminodiphenylmethane, 4,4'- (or 3,4'-, 3,3'-, 2,4'-, 2,2'-) diaminodiphenyl ether, 4,4'- (or 3, 4'-, 3,3 '
-, 2,4'-, 2,2'-) diaminodiphenyl sulfone, 4,4'- (or 3,4'-, 3,3'-, 2,4'-,
2,2 '-) diaminodiphenyl sulfide, 4,4'-
(Or 3,3 ′-) benzophenonediamine, 2,2-
Bis [4- (4-aminophenoxy) phenyl] propane, 4,4′-diaminobenzanilide and the like. One or more of these (a) diisocyanates or diamines can be used. (B) The dicarboxylic acid and / or tricarboxylic anhydride are not particularly limited, and examples thereof include succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, dodecandioic acid, and eicosan as aliphatic dicarboxylic acids. Examples include diacids, dicarboxylic acids containing an alkylene ether bond, dicarboxylic acids containing an alkylene carbonate bond, dicarboxylic acids containing a butadiene bond, dicarboxylic acids containing a hydrogenated butadiene bond, and dicarboxylic acids containing a dimethylsiloxane bond. In addition, alicyclic dicarboxylic acids (dimer acid, 1,4-
Cyclohexanedicarboxylic acid, etc.), heterocyclic dicarboxylic acid (pyridinedicarboxylic acid, etc.), aromatic dicarboxylic acid (phthalic acid, isophthalic acid, terephthalic acid, 1,5-naphthalenedicarboxylic acid, 4,4′-diphenylether dicarboxylic acid, 4 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-benzophenonedicarboxylic acid, bis (4-
Carboxymethoxyphenyl) dimethylmethane, trimellitic anhydride / diamine = 2 mol / 1 mol imide bond-containing dicarboxylic acid as reaction product, etc.), aromatic tricarboxylic anhydride (trimellitic anhydride etc.), etc. Can be One or more of these (b) dicarboxylic acids and / or tricarboxylic anhydrides can be used.
The mixing ratio of (a) diisocyanate or diamine and (b) dicarboxylic acid for producing component (A) [carboxyl group in component (b) / isocyanate group or amino group in component (a)] is as follows: It is preferable to set the equivalent to less than 1 equivalent / 1 equivalent, preferably 1 equivalent / 0.5 equivalent to 1 equivalent /
0.97 equivalent is more preferred, 1 equivalent / 0.67 equivalent to 1 equivalent.
The equivalent weight / 0.95 equivalent is particularly preferable, and it is extremely preferable to be 1 equivalent / 0.75 equivalent to 1 equivalent / 0.91 equivalent. When the compounding ratio is 1 equivalent / 1 equivalent or more,
The component (a) tends to remain as an unreacted product, and the terminal of the reaction product is unlikely to become a carboxylic acid,
The yield of the component (A) tends to decrease. The reaction between the component (a) and the component (b) can be performed in an organic solvent.
The organic solvent is not particularly limited. For example, amide solvents (N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, etc.), urea solvents (N, N-dimethylethyleneurea) , N, N-dimethylpropylene urea, tetramethylurea, etc.), lactone solvents (γ-butyrolactone, γ-caprolactone, etc.), carbonate solvents (propylene carbonate, etc.), ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.) ), Ester solvents (ethyl acetate, n-butyl acetate, butyl cellosolve acetate, butyl carbitol acetate, ethyl cellosolve acetate, ethyl carbitol acetate, etc.),
Examples include glyme-based solvents (diglyme, triglyme, tetraglyme, etc.), hydrocarbon-based solvents (toluene, xylene, cyclohexane, etc.), and sulfone-based solvents (sulfolane, etc.). Among the above, amide solvents and urea solvents are preferable in terms of high solubility, high reaction promoting property and the like. Among them, active hydrogen which easily inhibits the reaction between the component (a) and the component (b) is preferable. N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylethylene urea, N, N-dimethylpropylene urea, and tetramethyl urea are more preferred in that they have no
-Methyl-2-pyrrolidone is particularly preferred. The amount of the organic solvent used is preferably 30 to 2,000 parts by weight, and more preferably 50 to 50 parts by weight based on 100 parts by weight of the total of the components (a) and (b).
1000 parts by weight is more preferable, and 70 to 400 is particularly preferable. If the amount of the solvent is less than 30 parts by weight, the solubility is poor, the reaction system tends to be non-uniform and the viscosity tends to be increased. If the amount exceeds 2,000 parts by weight, the reaction is difficult to proceed and the reaction is difficult to complete. There is. One or more of these organic solvents can be used. (A) component and (b)
The reaction temperature of the components is preferably from 40 to 300 ° C,
-250 ° C is more preferable, and 120-220 ° C is particularly preferable. If the reaction temperature is lower than 40 ° C., the reaction does not easily proceed and the reaction tends to be difficult to complete. If the reaction temperature exceeds 300 ° C., gelation or the like due to a side reaction tends to occur, and the reaction tends to be difficult to control. The epoxy resin (B) used in the present invention is not particularly limited. For example, bisphenol A epoxy resin, tetrabromobisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol AD epoxy resin as a bifunctional aromatic glycidyl ether , Naphthalene type epoxy resin, biphenyl type epoxy resin, tetramethyl biphenyl type epoxy resin and the like. Examples of the polyfunctional aromatic glycidyl ether include phenol novolak type epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene-phenol type epoxy resin, and tetraphenylolethane type epoxy resin. Epoxy resins, polypropylene glycol-type epoxy resins, neopentyl glycol-type epoxy resins, dibromoneopentyl glycol-type epoxy resins, hexanediol-type epoxy resins, and the like. Bifunctional alicyclic glycidyl ether (hydrogenated bisphenol A type epoxy resin, etc.), polyfunctional aliphatic glycidyl ether (trimethylolpropane type epoxy resin, sorbitol type epoxy resin, glycerin type epoxy resin, etc.), bifunctional aromatic glycidyl Esters (such as diglycidyl phthalate), bifunctional alicyclic glycidyl esters (such as diglycidyl tetrahydrophthalate and diglycidyl hexahydrophthalate),
Bifunctional aromatic glycidylamine (N, N-diglycidylaniline, N, N-diglycidyltrifluoromethylaniline, etc.), polyfunctional aromatic glycidylamine (N, N,
N ', N'-tetraglycidyl-4,4-diaminodiphenylmethane, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, N, O-triglycidyl-p-
Aminophenol, etc.), bifunctional alicyclic epoxy resin (alicyclic diepoxy acetal, alicyclic diepoxy adipate, alicyclic diepoxycarboxylate, vinylcyclohexene dioxide, etc.), bifunctional heterocyclic epoxy resin ( Diglycidyl hydantoin), polyfunctional heterocyclic epoxy resin (triglycidyl isocyanurate, etc.), difunctional or polyfunctional silicon-containing epoxy resin (organopolysiloxane type epoxy resin, etc.). A bifunctional epoxy resin is preferred in terms of ease of use and the like. Among the bifunctional epoxy resins, bifunctional aromatic glycidyl ether is more preferable in terms of heat resistance improvement, among which,
A bisphenol A type epoxy resin is particularly preferred in terms of cost and the like. One or more of these (B) epoxy resins are used. The polyoxyalkylene monoamine (C) used in the present invention is not particularly limited, and for example, the general formula [1]

Embedded image (Wherein, R represents a hydrogen atom or a methyl group, and n is a positive integer). Among them, a polyoxyalkylene monoamine represented by the following formula is obtained. In this respect, polyoxyalkylene monoamines having a molecular weight of 600 to 2,000 are preferred. Examples of such polyoxyalkylene monoamines include, for example, Jeffamine M-600, M-1000, M-2005, and M-20 manufactured by Huntsman Corporation.
70 and the like. One or more of these (C) polyoxyalkylene monoamines are used. (A) component,
The mixing ratio of the component (B) and the component (C) is such that the active hydrogen derived from the epoxy group in the component (B) / the active hydrogen derived from the carboxyl group in the component (A) and the active hydrogen derived from the amino group in the component (C). Is preferably less than 1 equivalent / 1 equivalent, more preferably 1 equivalent / 0.25 equivalent to 1 equivalent / 0.90 equivalent, and more preferably 1 equivalent / 0.33 equivalent to 1 equivalent /.
It is particularly preferred that the equivalent amount be 0.83 equivalent, that is, 1 equivalent / 0.4.
It is extremely preferred that the amount be 5 equivalents to 1 equivalent / 0.67 equivalents. When the mixing ratio is 1 equivalent / 1 equivalent or more, the thermosetting property is easily deteriorated, and the chemical resistance tends to decrease.
In the reaction of the components (A), (B) and (C), it is preferable that the components (A) and (C) are not directly reacted. Specifically, after reacting the component (B) and the component (C), it is more preferable to react the component (A) with the reaction product. In particular, the components (A) and (B) The component (C) is preferably reacted with the reaction product of (1). When the component (A) and the component (C) are directly reacted, a resin having a component (C) residue at a terminal is easily produced as a by-product, and the thermosetting resin of the present invention having a component (C) residue in a side chain. The yield of the polyamide resin tends to decrease. (A) component, (B)
The reaction of the component and the component (C) is performed in an organic solvent. The organic solvent is not particularly limited, and includes, for example, the organic solvents that can be used in producing the component (A) described above. Among them, nitrogen-containing polar solvents (amide solvents, amide solvents,
Urea-based solvents). Among them, N-methyl-2-pyrrolidone, N-methyl-2-pyrrolidone, and the like in that they do not have active hydrogen which easily inhibits the reaction of the components (A), (B) and (C). N, N-dimethylacetamide, N, N-dimethylethyleneurea, N, N-dimethylpropyleneurea, and tetramethylurea are more preferred, and among them, N-methyl-2-pyrrolidone is particularly preferred. The amount of the organic solvent to be used is preferably 30 to 2,000 parts by weight, more preferably 50 to 1,000 parts by weight, and more preferably 70 to 1,000 parts by weight, per 100 parts by weight of the total of the components (A), (B) and (C). 40
0 is particularly preferred. If the amount of the organic solvent is less than 30 parts by weight, the solubility is poor, and the reaction system tends to be non-uniform or highly viscous. If the amount exceeds 2,000 parts by weight, the reaction does not easily proceed and the reaction tends to be difficult to complete. . One or more of these organic solvents are used. The reaction temperature of the component (A), the component (B) and the component (C) is preferably 40 to 300 ° C, more preferably 100 to 250 ° C, and 120 to 220 ° C.
C is particularly preferred. If the reaction temperature is lower than 40 ° C., the reaction does not easily proceed and the reaction tends to be difficult to complete. If the reaction temperature exceeds 300 ° C., gelation or the like due to side reactions tends to occur, and the reaction tends to be difficult to control. In the present invention, a catalyst can be used if necessary. Examples of the reaction catalyst include tertiary amines such as triethylamine, triethylenediamine, N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, N, N'-dimethylpiperazine, pyridine, picoline, 1,8-diazabicyclo [5,4,0] undecene-7 and the like. 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-methyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole as an imidazole compound,
2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-azine-2-methylimidazole and the like. Organotin compounds (dibutyltin dilaurate,
1,3-diacetoxytetrabutyldistannoxane, etc., quaternary onium salts (tetraethylammonium bromide, tetrabutylammonium bromide, benzyltriethylammonium chloride, trioctylmethylammonium chloride, cetyltrimethylammonium bromide, tetraiodide Butylammonium, dodecyltrimethylammonium iodide, benzyldimethyltetradecylammonium acetate, tetraphenylphosphonium chloride, triphenylmethylphosphonium chloride, tetramethylphosphonium bromide, etc., and organic phosphorus compounds (3-methyl-1-phenyl-2-phospholene) -1-oxide, etc.), organic acid alkali metal salts (sodium benzoate, potassium benzoate, etc.), inorganic salts (zinc chloride, iron chloride, lithium chloride, lithium bromide, etc.), metal carb Carbonyl compounds (eg, octacarbonyldicobalt (cobaltcarbonyl)). One or more of these catalysts can be used.
The binder resin obtained by the method described above has a high polarity and a strong hydrogen bond between the bond between the nitrogen atom and the carbon atom of the amide bond, and has a large bond energy, so that heat resistance, adhesiveness and Excellent electrolyte resistance.
In addition, the polyoxyalkylene monoamine (C) component residue in the side chain is excellent in flexibility. By adding a polyfunctional compound such as an epoxy resin or bismaleimide, a blocked isocyanate compound, or a melamine compound as a cross-linking agent to these non-aqueous solvent-based binder compositions, heat resistance, adhesiveness, and electrolyte resistance are improved. A better non-aqueous solvent-based binder composition is obtained. The epoxy resin (B) can be used as the epoxy resin. Examples of the blocked isocyanate compound include tolylene diisocyanate, hexamethylene isocyanate, isophorone diisocyanate and derivatives thereof,
For example, Coronate 25 manufactured by Nippon Polyurethane Industry Co., Ltd.
13, 2507, 2515, 2512, Desmodule BL3175, BL41 manufactured by Sumitomo Bayer Urethane Co., Ltd.
65 and the like. Examples of the melamine compound include melamine manufactured by American Cyanamid and Mitsui Toatsu Cymel, for example, Cymel (registered trademark) 300, 301, 3
03, 350, 370, 380, 1116 and 113
0, benzoguanamines such as Cymel® 1123 and 1125, the glycoluril resin Cymel® 1170, 1171 and 1172, and
Urea-based resin Beetle® 60, 65 and 80. As bismaleimide, bis
(4-maleimidophenyl) methane, 2,2-bis [4-
(4-maleimidophenoxy) phenyl] propane and the like. The amount of the polyfunctional compound to be added is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the non-aqueous solvent-based binder composition. Further, a binder composition obtained by mixing a non-aqueous solvent-based binder composition with a thermoplastic resin such as a polyamide resin, a polyimide resin, a polyamide-imide resin, a polyester resin, a polyvinylidene fluoride resin, and polytetrafluoroethylene has excellent heat resistance. It is possible to impart good flexibility while maintaining the adhesiveness and the resistance to the electrolytic solution. However, if a fluorine-containing thermoplastic resin such as polyvinylidene fluoride resin or polytetrafluoroethylene is mixed, hydrogen fluoride may be generated at a high temperature, so that polyamide resin, polyimide resin, polyamideimide resin, polyester resin Thermoplastic resins containing no fluorine atom are preferred. The electrode obtained by mixing the non-aqueous solvent-based binder composition and the active material, applying the mixture on the surface of the electrode substrate, and removing the polar non-aqueous solvent adheres the mixture layer containing the active material and the metal foil as the electrode substrate. It is excellent in electrolyte properties, excellent in electrolyte solution resistance and heat resistance, and can maintain the adhesion strength between the electrode substrate and the mixture layer and between the mixture layers for a long period of time even when used at a high temperature. When the adhesion strength between the electrode substrate and the mixture layer and the mixture layer is improved, the amount of the non-aqueous solvent-based binder composition in the mixture can be reduced, and as a result, the amount of the active material can be increased, A battery using such an electrode can increase the volume energy density. Batteries using electrodes that maintain the adhesion strength between the electrode base and the mixture layer and between the mixture layers for a long period of time can maintain a conductive network between the electrode substrate and the mixture layer and between the mixture layers even after repeated charging and discharging. Since the charge and discharge reactions can be maintained uniformly, the cycle life characteristics can be improved. The active material may be a transition metal oxide capable of reversibly inserting and releasing lithium ions, and may be a lithium cobalt composite oxide, a lithium nickel composite oxide, or a mixture thereof. Also, in the lithium nickel composite oxide, Al, V, Cr, Fe, Co, Sr, M
It may be a lithium-nickel composite oxide in which nickel sites or lithium sites are substituted by one kind of metal selected from o, W, Mn, B, and Mg. In the lithium manganese composite oxide, Li, Al, V, Cr, Fe, Co,
A lithium manganese composite oxide in which a manganese site or a lithium site is substituted by at least one metal selected from Ni, Mo, W, Zn, B, and Mg may be used. on the other hand,
Pitch coke, petroleum coke,
Graphite, carbon fiber, activated carbon and the like or a mixture thereof may be used. Although N-methyl-2-pyrrolidone was used as the dispersion solvent, any organic solvent capable of uniformly dissolving or dispersing the non-aqueous solvent-based binder composition may be used, and a mixture of a plurality of organic solvents may be used. As the solvent that can be used, the above-mentioned solvents that can be used for the synthesis of the binder resin can be used as they are, but N-methyl-2-pyrrolidone and N-methyl-2-pyrrolidone and ester solvents (ethyl acetate, n-butyl acetate) can be used. , Butyl cellosolve acetate, butyl carbitol acetate, ethyl cellosolve acetate,
Ethyl carbitol acetate, etc.) or glyme solvents (diglyme, triglyme, tetraglyme, etc.)
Is particularly preferred.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preparation of Non-Aqueous Solvent-Based Binder Composition A specific example of the non-aqueous solvent-based binder composition of the present invention will be specifically described. [Preparation Example 1] In a 1-liter separable flask equipped with a stirrer, a thermometer, a cooling condenser, and a nitrogen gas inlet tube, (a) 4,4'-diphenylmethane diisocyanate 11 as a diisocyanate in a nitrogen atmosphere.
5.87 g (0.463 mol) of (b) adipic acid 2 as dicarboxylic acid and / or tricarboxylic anhydride
4.36 g (0.167 mol), sebacic acid 44.95 g
(0.222 mol), 38.39 g of dodecanedioic acid (0.1
67 mol) and 252.8 g of N-methyl-2-pyrrolidone as an organic solvent, and the mixture was heated to 130 ° C.
On the way, the reaction system became a homogeneous solution at about 100 ° C., and carbon dioxide gas accompanying the amidation reaction began to be generated. 130 ° C
When the reaction was advanced for 2 hours and then at 170 ° C. for 2 hours, the generation of carbon dioxide gas disappeared, and a solution of the (A) polyamide-based resin intermediate was obtained. Subsequently, a bisphenol A-type epoxy resin obtained by dissolving this (A) polyamide-based resin intermediate solution in 92.6 g of N-methyl-2-pyrrolidone as an epoxy resin in a state where the solution of the polyamide resin intermediate was kept at 170 ° C. (Epoxy equivalent 187 g / eq.) 88.75 g (0.
(238 mol) was added dropwise over 5 minutes. When the reaction was allowed to proceed for 1 hour at the same temperature, the product (C) was dissolved in 103.8 g of N-methyl-2-pyrrolidone as a polyoxyalkylene monoamine, and was manufactured by Huntsman Corporation under the trade name Jeffamine M-1000 (the above-mentioned general formula [ 1], n: 22, R: hydrogen atom / methyl group = 19 /
3, a solution of 27.90 g (0.023 mol) of a primary amino group-equivalent molecular weight: 1205, catalog value above was added dropwise over 5 minutes. After further proceeding the reaction at the same temperature for 1 hour, N
After adding 249.6 g of -methyl-2-pyrrolidone and cooling, a non-aqueous solvent-based binder composition of the present invention having a component (C) residue in a side chain was obtained. [Preparation Example 2] In a 1-liter separable flask equipped with a stirrer, a thermometer, a cooling condenser and a nitrogen gas inlet tube, under a nitrogen atmosphere (a) 4,4'-diphenylmethane diisocyanate as a diisocyanate 1000.1
0 g (0.400 mol) (b) 21.04 adipic acid as dicarboxylic and / or tricarboxylic anhydride
g (0.144 mol), 38.83 g of sebacic acid (0.1
92 mol), 33.16 g (0.144 mol) of dodecanedioic acid and 218.4 g of N-methyl-2-pyrrolidone as an organic solvent were charged and heated to 130 ° C. On the way,
At about 100 ° C., the reaction system became a homogeneous solution state, and carbon dioxide gas began to be generated due to the amidation reaction. When the reaction was allowed to proceed at 130 ° C. for 2 hours and then at 170 ° C. for 2 hours, the generation of carbon dioxide gas disappeared, and a solution of (A) a polyamide resin intermediate was obtained. Subsequently, the solution of this (A) polyamide-based resin intermediate was kept at 170 ° C.
N-methyl-2-pyrrolidone 120 as an epoxy resin
A solution of 92.00 g (0.246 mol) of bisphenol A type epoxy resin (epoxy equivalent: 187 g / eq.) dissolved in g was added dropwise over 5 minutes. When the reaction was allowed to proceed for 1 hour at the same temperature, (C) N-methyl-2-pyrrolidone 10 as polyoxyalkylene monoamine was added.
Jeffamine M-1000 (trade name, manufactured by Huntsman Corporation) dissolved in 8.8 g (n: 22, R: hydrogen atom / methyl group = 19/3 in the general formula [1], molecular weight in terms of primary amino group: 1,205, or more) Catalog value) 48.
20 g (0.040 mol) of the solution were added dropwise over 5 minutes. After further proceeding the reaction at the same temperature for 1 hour, 248.5 g of N-methyl-2-pyrrolidone was added and cooled, and the non-aqueous solvent-based binder composition of the present invention having the component (C) residue in the side chain was added. I got [Preparation Example 3] In a 1-liter separable flask equipped with a stirrer, a thermometer, a cooling condenser, and a nitrogen gas inlet tube, under a nitrogen atmosphere (a) 4,4'-diphenylmethane diisocyanate as a diisocyanate 115.
12 g (0.460 mol) (b) dicarboxylic acid and / or
Or adipic acid 24.2 as tricarboxylic anhydride
0 g (0.166 mol), 44.66 g of sebacic acid (0.16 mol).
221 mol), 38.14 g (0.166 mol) of dodecanedioic acid and 251.2 g of N-methyl-2-pyrrolidone as an organic solvent were charged and heated to 130 ° C. On the way,
At about 100 ° C., the reaction system became a homogeneous solution state, and carbon dioxide gas began to be generated due to the amidation reaction. When the reaction was allowed to proceed at 130 ° C. for 2 hours and then at 170 ° C. for 2 hours, the generation of carbon dioxide gas disappeared, and a solution of (A) a polyamide resin intermediate was obtained. Subsequently, the solution of this (A) polyamide-based resin intermediate was kept at 170 ° C.
N-methyl-2-pyrrolidone 10 as an epoxy resin
Bisphenol A type epoxy resin (epoxy equivalent: 187 g / eq.) Dissolved in 5.3 g (61.93 g, 0.1 g)
66 mol) was added dropwise over 5 minutes. 1 at the same temperature
After proceeding with the time reaction, Jeffamine M-1000 (trade name, manufactured by Huntsman Corporation) (C) was dissolved in 92.0 g of N-methyl-2-pyrrolidone as a polyoxyalkylene monoamine (C).
N: 22, R: hydrogen atom / methyl group = 19/3, molecular weight in terms of primary amino group: 1,205, catalog value above 5)
5.43 g (0.046 mol) of the solution were added dropwise over 5 minutes. After further proceeding the reaction at the same temperature for 1 hour, 249.2 g of N-methyl-2-pyrrolidone was added and cooled, and the non-aqueous solvent-based binder composition of the present invention having the component (C) residue in the side chain was added. I got [Preparation Example 4] N- of the binder resin obtained in Preparation Example 1
100.0 g of a methyl-2-pyrrolidone solution (solid content: 42
%), 8.3 g of a blocked polyisocyanate crosslinking agent (hexamethylene diisocyanate trimer 2-butanone oxime block) was added to obtain a binder composition solution. [Preparation Example 5] N- of the binder resin obtained in Preparation Example 1
100.0 g of a methyl-2-pyrrolidone solution (solid content: 42
%), 8.3 g of a melamine resin crosslinking agent (hexamethoxymethylol melamine) was added to obtain a binder composition solution. [Preparation Example 6] N- of the binder resin obtained in Preparation Example 1
100.0 g of a methyl-2-pyrrolidone solution (solid content: 42
%), 8.3 g of an epoxy resin crosslinking agent (4,4'-isopropylidenebisphenol diglycidyl ether) was added to obtain a binder composition solution. [Preparation Example 7] N- of the binder resin obtained in Preparation Example 1
100.0 g of a methyl-2-pyrrolidone solution (solid content: 42
%), 8.3 g of a bismaleimide crosslinking agent (bis (4-maleimidophenyl) methane) was added to obtain a binder composition solution. The binder composition solutions obtained in Preparation Examples 1 to 7 and an N-methyl-2-pyrrolidone solution of polyvinylidene fluoride (KF manufactured by Kureha Chemical Co., Ltd.) as a comparative resin composition
-1100) was cast on a rolled copper foil or aluminum foil by an applicator method so as to have a dry film thickness of about 30 μm, and was preliminarily dried at 90 ° C. for 10 minutes, and then dried at 150 ° C.
For 1 hour to prepare a cured coating film. Apply a two-part curing type epoxy resin adhesive on this cured coating film,
The coated surface was pressed against a glass plate and cured at room temperature for 12 hours to obtain a double-sided adhesive cured coating film. This cured coating film was evaluated for adhesiveness (peel strength to the rolled copper foil surface or aluminum foil surface).

[Table 1] In the resin compositions shown in Preparation Examples 1 to 3, the adhesive strength of the binder resin composition to the base material was improved as compared with polyvinylidene fluoride as the comparative resin composition. In Preparation Examples 4 to 7 in which various crosslinking agents were added to the resin of Preparation Example 1,
A further improvement in adhesion was observed with the addition of the crosslinking agent. 2. Preparation of Positive Electrode [Example 1] A lithium manganate having an average particle diameter of 10 µm, a carbon powder having an average particle diameter of 3 µm, and the nonaqueous solvent-based binder composition of Preparation Example 1 were mixed at a ratio of 80:10:10 (% by volume). )
, And N-methyl-2-pyrrolidone is added to form a slurry-like solution. The solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. The mixture application amount is 29 per side
0 g / m ² . The mixture was rolled with a roll press so that the bulk density of the mixture became 2.6 g / cm ³ , and cut into a width of 54 mm to produce a strip-shaped positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and thereafter, a residual solvent in the electrode, 150 ° C. for removal of adsorbed water and crosslinking of the non-aqueous solvent-based binder composition.
For 16 hours to obtain a positive electrode mixture electrode. Incidentally, it was used reversibly intercalate lithium ions, Li _{1. 12} Mn _1.88 O ₄ and refers to the composition of lithium-manganese composite oxide as the transition metal oxide capable of releasing in this embodiment. Example 2 A positive electrode was obtained in the same manner as in Example 1, except that a 60: 40% by weight mixture of N-methyl-2-pyrrolidone and triglyme was used as a dispersion solvent used for preparing a slurry-like solution. Was. Example 3 A positive electrode was prepared in the same manner as in Example 1 except that a 60: 40% by weight mixture of N-methyl-2-pyrrolidone and ethyl carbitol acetate was used as a dispersion solvent used when preparing a slurry-like solution. Obtained. Example 4 A positive electrode was obtained in the same manner as in Example 1 except that the nonaqueous solvent-based binder composition used in Preparation Example 2 was used. Example 5 A positive electrode was obtained in the same manner as in Example 1 except that the nonaqueous solvent-based binder composition used in Preparation Example 3 was used. [Example 6] Lithium manganate having an average particle size of 10 µm, carbon powder having an average particle size of 3 µm, the binder resin obtained in Preparation Example 1, and a blocked polyisocyanate crosslinking agent (2-butanone of hexamethylene diisocyanate trimer) (Oxime block) at a ratio (volume%) of 80: 10: 8: 2, and the mixture is added to and mixed with N-methyl-2-pyrrolidone to prepare a slurry-like solution. This solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. The amount of the mixture applied is 290 g / m ² on one side. The mixture bulk density is 2.6 g /
so as to be in cm ^3, it was rolled by a roll press machine, 54m
By cutting into a width of m, a strip-shaped positive electrode mixture electrode sheet was prepared. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then 150 ° C. for removal of residual solvent and adsorbed water in the electrode and thermal curing of the binder resin.
For 16 hours to obtain a positive electrode mixture electrode. Example 7 80 parts of lithium manganate having an average particle size of 10 μm, carbon powder having an average particle size of 3 μm, the binder resin obtained in Preparation Example 1, and a melamine resin crosslinking agent (hexamethoxymethylolmelamine) were used. Mix at a ratio of 10: 9.5: 0.5 (vol%) and add N-methyl-2-pyrrolidone to make a slurry-like solution. This solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. The amount of the mixture applied is 290 g / m ² on one side. The mixture bulk density is 2.6
g / cm ³ and rolled with a roll press
It was cut to a width of 4 mm to produce a strip-shaped positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then removed to remove residual solvent and adsorbed water in the electrode and to cure the binder resin by heat.
Vacuum drying was performed at 16 ° C. for 16 hours to obtain a positive electrode mixture electrode. [Example 8] Lithium manganate having an average particle size of 10 µm, carbon powder having an average particle size of 3 µm, the binder resin obtained in Preparation Example 1, and an epoxy resin crosslinking agent (4,4'-isopropylidenebisphenol diglycidyl) Ether) in a ratio of 80: 10: 9.5: 0.5 (% by volume),
N-methyl-2-pyrrolidone is added to make a slurry-like solution. This solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. 290 g / m on one side
² So that the mixture bulk density becomes 2.6 g / cm ³
It was rolled with a roll press and cut into a width of 54 mm to produce a strip-shaped positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then vacuum-dried at 150 ° C. for 16 hours to remove the residual solvent and adsorbed water in the electrode and thermally cure the binder resin. Thus, a positive electrode mixture electrode was obtained. Example 9 Lithium manganate having an average particle size of 10 μm, carbon powder having an average particle size of 3 μm, the binder resin obtained in Preparation Example 1, and a bismaleimide crosslinking agent [bis (4-maleimidophenyl) methane] To 80: 10: 9.5:
Mix at a ratio of 0.5 (vol%) and add N-methyl-2-pyrrolidone to make a slurry-like solution. Thickness 20
This solution is applied to both sides of a μm aluminum foil and dried. The amount of the mixture applied is 290 g / m ² on one side. The mixture was rolled with a roll press so that the bulk density of the mixture became 2.6 g / cm ³ , and cut into a width of 54 mm to produce a strip-shaped positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then vacuum-dried at 150 ° C. for 16 hours to remove the residual solvent and adsorbed water in the electrode and thermally cure the binder resin. Thus, a positive electrode mixture electrode was obtained. Example 10 Lithium cobalt oxide having an average particle diameter of 10 μm, carbon powder having an average particle diameter of 3 μm, and the nonaqueous solvent-based binder composition of Preparation Example 1 were mixed at a ratio of 80:10:10 (vol%). Then, N-methyl-2-pyrrolidone is added to prepare a slurry-like solution. This solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. The amount of the mixture applied is 289 g / m ² on one side. The mixture bulk density is 3.6 g / cm ³
Was rolled with a roll press, and cut into a width of 54 mm to produce a strip-shaped positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then 150 ° C. for removing residual solvent and adsorbed water in the electrode and crosslinking the non-aqueous solvent-based binder composition.
For 16 hours to obtain a positive electrode mixture electrode. Example 11 Lithium nickelate having an average particle size of 10 μm, carbon powder having an average particle size of 3 μm, and the nonaqueous solvent-based binder composition of Preparation Example 1 were mixed at a ratio of 80:10:10 (vol%). Then, N-methyl-2-pyrrolidone is added to prepare a slurry-like solution. This solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. The mixture application amount is 220 g / m ² on one side. The bulk density of the mixture is 3.5 g / cm ³
Was rolled with a roll press, and cut into a width of 54 mm to produce a strip-shaped positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then 150 ° C. for removing residual solvent and adsorbed water in the electrode and crosslinking the non-aqueous solvent-based binder composition.
For 16 hours to obtain a positive electrode mixture electrode. Comparative Example 1 Lithium manganate having an average particle size of 10 μm, carbon powder having an average particle size of 3 μm, and polyvinylidene fluoride resin were mixed at a ratio (volume%) of 80:10:10, and N-methyl-2 was added. -Add pyrrolidone to make a slurry-like solution. This solution is applied to both sides of an aluminum foil having a thickness of 20 μm and dried. The mixture application amount is 290 on one side
g / m ² . The mixture was rolled with a roll press so that the bulk density of the mixture became 2.6 g / cm ³ , and cut into a width of 54 mm to produce a short positive electrode mixture electrode sheet. A current collector tab made of aluminum was ultrasonically welded to the end of the positive electrode mixture electrode sheet, and then vacuum-dried at 150 ° C. for 16 hours for removal of residual solvent and adsorbed water in the electrode and thermal curing of the binder resin. A positive electrode mixture electrode was obtained. Comparative Example 2 A positive electrode was obtained in the same manner as in Comparative Example 1, except that lithium cobaltate having an average particle size of 10 μm was used as the positive electrode active material. Comparative Example 3 A positive electrode was obtained in the same manner as in Comparative Example 1, except that lithium nickelate having an average particle size of 10 μm was used as the positive electrode active material. 3. Preparation of Negative Electrode [Example 12] Amorphous carbon having an average particle diameter of 20 µm and the nonaqueous solvent-based binder composition of Preparation Example 1 were mixed at a ratio of 90:10 (vol%), and N-methyl-2 was added. Add pyrrolidone to make a slurry-like solution. This solution is applied to both sides of a copper foil having a thickness of 10 μm and dried. The amount of the mixture applied is 65 g / m ² on one side. The mixture was rolled with a roll press so that the bulk density of the mixture became 1.0 g / cm ³ , and cut into a width of 56 mm to prepare a strip-shaped negative electrode mixture electrode sheet. A current collector tab made of nickel was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then removed at 150 ° C. for removal of residual solvent and adsorbed water in the electrode and crosslinking of the non-aqueous solvent-based binder composition.
After vacuum drying for an hour, a negative electrode mixture electrode was obtained. Example 13 Example 1 was repeated except that a 60: 40% by weight mixture of N-methyl-2-pyrrolidone and triglyme was used as a dispersion solvent used when preparing a slurry-like solution.
In the same manner as in 2, a negative electrode was obtained. Example 14 A negative electrode was prepared in the same manner as in Example 12, except that a 60: 40% by weight mixture of N-methyl-2-pyrrolidone and ethyl carbitol acetate was used as a dispersion solvent for preparing the slurry-like solution. An electrode was obtained. [Example 15] A negative electrode was obtained in the same manner as in Example 12, except that Preparation Example 2 was used as the nonaqueous solvent-based binder composition. Example 16 A negative electrode was obtained in the same manner as in Example 12 except that the nonaqueous solvent-based binder composition used in Preparation Example 3 was used. [Example 17] Amorphous carbon having an average particle diameter of 20 µm, the nonaqueous solvent-based binder composition of Preparation Example 1, and a blocked polyisocyanate crosslinking agent (2-butanone oxime block of hexamethylene diisocyanate trimer) To 90:
Mix at a ratio of 8: 2 (volume%) and add N-methyl-2-pyrrolidone to prepare a slurry-like solution. Thickness 1
This solution is applied to both sides of a 0 μm copper foil and dried. The amount of the mixture applied is 65 g / m ² on one side. The mixture bulk density is 1.0g
/ Cm ³ , and rolled to 56
The resultant was cut to a width of mm to prepare a strip-shaped negative electrode mixture electrode sheet. A nickel current-collecting tab was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then a residual solvent, adsorbed water in the electrode was removed, and a non-aqueous solvent-based binder composition was cross-linked.
Vacuum drying was performed at 50 ° C. for 16 hours to obtain a negative electrode mixture electrode. [Example 18] Amorphous carbon having an average particle diameter of 20 µm, the non-aqueous solvent-based binder composition of Preparation Example 1, and a melamine resin crosslinking agent (hexamethoxymethylolmelamine) 90:
9.5: 0.5 (vol.%) Mixed in N-methyl-
Add 2-pyrrolidone to make a slurry-like solution.
This solution is applied to both sides of a copper foil having a thickness of 10 μm and dried. The amount of the mixture applied is 65 g / m ² on one side. The mixture was rolled with a roll press so that the bulk density of the mixture became 1.0 g / cm ³ , and cut into a width of 56 mm to prepare a strip-shaped negative electrode mixture electrode sheet. A current collector tab made of nickel was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then the residual solvent in the electrode,
Vacuum drying was performed at 150 ° C. for 16 hours to remove the adsorbed water and crosslink the non-aqueous solvent-based binder composition to obtain a negative electrode mixture electrode. Example 19 Amorphous carbon having an average particle diameter of 20 μm, the non-aqueous solvent-based binder composition of Preparation Example 1, and an epoxy resin crosslinking agent (4,4′-isopropylidenebisphenol diglycidyl ether) were mixed with 90: Mix at a ratio of 9.5: 0.5 (% by volume), add N-methyl-2-pyrrolidone,
Make a slurry-like solution. This solution is applied to both sides of a copper foil having a thickness of 10 μm and dried. The mixture application amount is 65g per side
/ M ² . The mixture was rolled with a roll press so that the bulk density of the mixture became 1.0 g / cm ³ , and cut into a width of 56 mm to prepare a strip-shaped negative electrode mixture electrode sheet. A current collector tab made of nickel was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then removed at 150 ° C. for removal of residual solvent and adsorbed water in the electrode and crosslinking of the non-aqueous solvent-based binder composition. After vacuum drying for an hour, a negative electrode mixture electrode was obtained. Example 20 Amorphous carbon having an average particle diameter of 20 μm, the non-aqueous solvent-based binder composition of Preparation Example 1, and a bismaleimide crosslinking agent [bis (4-maleimidophenyl 9 methane)]
Mix at a ratio of 0: 9.5: 0.5 (vol%) and add N-methyl-2-pyrrolidone to make a slurry-like solution. This solution is applied to both sides of a copper foil having a thickness of 10 μm and dried. The amount of the mixture applied is 65 g / m ² on one side. The mixture was rolled with a roll press so that the bulk density of the mixture became 1.0 g / cm ³ , and cut into a width of 56 mm to prepare a strip-shaped negative electrode mixture electrode sheet. A current collector tab made of nickel was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then removed at 150 ° C. for removal of residual solvent and adsorbed water in the electrode and crosslinking of the non-aqueous solvent-based binder composition. After vacuum drying for an hour, a negative electrode mixture electrode was obtained. [Example 21] Artificial graphite having an average particle diameter of 20 µm and the nonaqueous solvent-based binder composition of Preparation Example 1 were mixed at a ratio of 90:10 (vol%), and N-methyl-2-pyrrolidone was added. To produce a slurry-like solution. This solution is applied to both sides of a copper foil having a thickness of 10 μm and dried. The mixture was applied such that the active material utilization rate per unit area facing the positive electrode was 1 or more for the negative electrode / positive electrode. When the lithium manganese composite oxide is used for the positive electrode active material of Example 1 or the like, 130 g / m ² on one side, and when the lithium nickel composite oxide is used for the positive electrode active material of Example 11 is 150 g / m 2 for one side.
² The bulk density of the mixture was 1.5 g / cm ^{3 in} each case.
Was rolled by a roll press and cut into a width of 56 mm to produce a strip-shaped negative electrode mixture electrode sheet. A current collector tab made of nickel was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then removed at 150 ° C. for removal of residual solvent and adsorbed water in the electrode and crosslinking of the non-aqueous solvent-based binder composition. After vacuum drying for an hour, a negative electrode mixture electrode was obtained. [Comparative Example 4] A negative electrode was prepared by mixing amorphous carbon having an average particle diameter of 20 µm and polyvinylidene fluoride resin in a ratio of 90:10 (volume%), adding N-methyl-2-pyrrolidone, and forming a slurry. To prepare a solution. This solution is applied to both sides of a copper foil having a thickness of 10 μm and dried. The mixture was applied such that the active material utilization rate per unit area facing the positive electrode was 1 or more for the negative electrode / positive electrode. When the lithium manganese composite oxide is used as the positive electrode active material of Example 1 and the like, the surface is 65 g / m ² on one side, and when the lithium cobalt composite oxide is used as the positive electrode active material of Example 10, the surface is 100 g / m ^{2 on} one side.
It is. The mixture was rolled by a roll press so that the bulk density was 1.0 g / cm ³ in each case, and cut into a width of 56 mm to prepare a strip-shaped negative electrode mixture electrode sheet. A nickel current collecting tab was ultrasonically welded to the end of the negative electrode mixture electrode sheet, and then vacuum-dried at 150 ° C. for 16 hours to remove the residual solvent and adsorbed water in the electrode and thermally cure the binder resin. Thus, a negative electrode mixture electrode was obtained. Comparative Example 5 A negative electrode was obtained in the same manner as in Example 21 except that a polyvinylidene fluoride resin was used instead of the nonaqueous solvent-based binder composition. The obtained electrode was evaluated for electrolytic solution resistance. In addition, as an electrolytic solution used for this,
(1) N-methyl-2-pyrrolidone or (2) a mixed solution of ethylene carbonate / dimethyl carbonate = 1/2 (volume ratio) in which LiPF ₆ is dissolved to a concentration of 1 M, and After the immersion at 50 ° C. for 24 hours, the presence or absence of abnormal appearance was examined by an electron microscope (1000 times magnification). The results are summarized in Table 2.

[Table 2] As shown in Table 2, when polyvinylidene fluoride is used as the binder resin, when the electrode mixture is immersed in the electrolytic solution at 50 ° C., the binder resin on the surface swells, and the electrode mixture is separated from the base material and the binder resin is removed. In contrast, in Examples 1 to 21, the resistance of the binder resin composition to the electrolytic solution was improved, and these phenomena were not observed. 4. Production of Battery The positive electrode mixture electrodes prepared in Examples 1 to 11 and Comparative Example 1 and the negative electrode mixture electrodes prepared in Examples 12 to 21 and Comparative Example 2 were combined as shown in Table 3. hand,
It is wound through a separator made of a microporous polyethylene film having a thickness of 25 μm and a width of 58 mm to form a spiral wound group.

[Table 3] The spiral wound group is inserted into a battery can, and a nickel tab terminal previously welded to the copper foil of the negative electrode current collector is welded to the bottom of the battery can. Next, L was added to a solution in which ethylene carbonate and dimethyl carbonate were mixed at a volume ratio of 1: 1.
5 ml of an electrolyte solution in which iPF ₆ was dissolved at a concentration of 1 mol / l was injected into the battery container. Next, an aluminum tab terminal, which was previously welded to the aluminum foil of the positive electrode current collector, was welded to the lid, and the lid was placed on top of the battery can via an insulating gasket. A cylindrical battery having a size of 18 mm × a height of 65 mm was produced. In this embodiment, an electrolytic solution in which LiPF ₆ was dissolved at a concentration of 1 mol / l in a solution in which ethylene carbonate and dimethyl carbonate were mixed at a volume ratio of 1: 1 was used. , Ethers, ketones, lactones, nitriles, amines, amides, sulfur compounds, chlorinated hydrocarbons, sulfolane compounds and the like. Among them, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, 1,2
-Diethoxyethane, diethyl carbonate, γ-butyrolactone, tetrahydrofuran, diethyl ether,
One or more of sulfolane, acetonitrile and the like are used, and a mixed solvent is particularly preferable. The electrolyte is also LiClO ₄ , Li
PF ₆ , LiPF ₄ , LiBF ₄ , LiCl, LiBr,
CH ₃ SO ₃ Li, LiAsF _{6 and the} like can be used. The batteries of the present invention products 1 to 15 and the comparative product 1 have a charging current of 40
After charging at a constant voltage of 0 mA and a limit voltage of 4.2 V, the battery was discharged at a discharge current of 800 mA until the discharge end voltage reached 2.7 V, and the initial capacity was measured. In addition, in order to confirm the amount of manganese eluted from the positive electrode active material into the electrolyte, the battery in a fully charged state is disassembled, and only the positive electrode is immersed in a new electrolyte and sealed. It was left in a thermostat set at 50 ° C. for 7 days, and the amount of manganese eluted in the electrolytic solution was measured using a plasma emission spectrometer (ICP). The batteries of the products 16 and 17 of the present invention and the battery of the comparative product 2 were charged at a constant voltage of 750 mA and a limit voltage of 4.2 V, then discharged at a discharge current of 1500 mA until the discharge end voltage reached 2.5 V, and the initial capacity was measured. did. The batteries of the invention product 18 and the comparison product 3 were charged at a constant voltage of 900 mA and a limit voltage of 4.15 V, then discharged at a discharge current of 1800 mA until the discharge end voltage reached 3.0 V, and the initial capacity was measured. did. The charge / discharge under these conditions was defined as one cycle, and the charge / discharge was repeated at an ambient temperature of 50 ° C. until the capacity reached 70% or less of the initial capacity, and a cycle life test was performed. The results are shown in Table 4 and FIG.

[Table 4] As shown in Table 4 and FIG. 1, the battery of Comparative Product 1 in which a positive electrode using lithium manganate as an active material, a polyvinylidene fluoride resin as a binder, and a negative electrode using polyvinylidene fluoride resin as a binder was used, 1
The life was reached in 00 cycles. On the other hand, the binder for at least one of the positive electrode and the negative electrode is a non-aqueous electrolyte secondary battery using a non-aqueous solvent-based binder composition (the present invention products 1 to 4).
15, 19, 20), it can be seen that the life is extended to 200 cycles or more. In particular, a non-aqueous electrolyte secondary battery using the non-aqueous solvent-based binder composition for the negative electrode binder (the present invention products 1, 3, 4, 6, 8, 10, 12 to 15, 19,
20) has improved cycle life characteristics. In addition, batteries using the mixed solvent of N-methyl-2-pyrrolidone alone and a poor solvent such as triglyme or ethyl carbitol acetate rather than N-methyl-2-pyrrolidone alone (Products 4 to 7 of the present invention) have further improved cycle life characteristics. ing. This suppresses migration and segregation to the surface of the non-aqueous solvent-based binder composition during the removal of the dispersion solvent by mixing the poor solvent,
This is probably because the distribution of the non-aqueous solvent-based binder composition in the positive electrode or negative electrode mixture was made uniform. When the battery after the life was disassembled, in Comparative Product 1, the negative electrode mixture was peeled off from the copper foil as the electrode substrate, and deposition of metallic lithium was confirmed in this portion. However, the non-aqueous solvent-based binder composition of the present invention was used. It is not seen in the electrode used. From this, the battery using the non-aqueous solvent-based binder composition of the present invention maintains excellent adhesion between the electrode substrate and the mixture layer interface and between the mixture layers. Think. Next, Table 5 shows the measurement results of the amount of manganese eluted in the electrolytic solution after the charged positive electrode was left at 50 ° C. for 7 days.

[Table 5] The positive electrode using lithium manganate as the active material and the non-aqueous solvent-based binder composition of the present invention as the binder has a smaller amount of manganese eluted in the electrolyte than the positive electrode of Comparative Example 1. This is considered to be because the binder was present so as to cover a part of the surface of the lithium manganese composite oxide particles, so that the contact area with the electrolytic solution was reduced and the amount of manganese eluted from the positive electrode active material could be reduced. When the elution of manganese from the positive electrode active material can be suppressed, the crystal structure of the positive electrode active material is stabilized and the electron conductivity is secured, and on the other hand, the deterioration of the negative electrode due to the eluted manganese can be suppressed.
The batteries of 2, 4 to 15, 19 are considered to have improved cycle life characteristics.

The polyamide resin intermediate (A) and the epoxy resin (A) obtained by reacting the diisocyanate or diamine (a) of the present invention with a dicarboxylic acid and / or tricarboxylic anhydride (b) in an organic solvent. The non-aqueous solvent-based binder composition obtained by reacting B) with the polyoxyalkylene monoamine (C) has a high polarity and a strong hydrogen bond between the bond between the nitrogen atom and the carbon atom of the amide bond, and Since it has binding energy, it is excellent in adhesiveness and resistance to electrolytic solutions at high temperatures. When a polyfunctional compound such as an epoxy resin, a bismaleimide, a blocked isocyanate compound, or a melamine compound is further added as a crosslinking agent to the non-aqueous solvent-based binder composition, the non-aqueous solvent has excellent adhesion and electrolytic solution resistance at high temperatures. A solvent-based binder composition is obtained. The electrode using the non-aqueous solvent-based binder composition and the battery using the electrode have excellent adhesion between the mixture layer containing the active material and the metal foil serving as the electrode substrate, and have excellent electrolytic solution resistance and heat resistance. It is excellent in property and can maintain the adhesion strength between the electrode substrate and the mixture layer and the mixture layer for a long period of time even when used at a high temperature. When the adhesion strength between the electrode substrate and the mixture layer and the mixture layer is improved, the amount of the non-aqueous solvent-based binder composition in the mixture can be reduced, and as a result, the amount of the active material can be increased, A battery using this electrode can increase the volume energy density. Batteries using electrodes that maintain the adhesion strength between the electrode substrate and the mixture layer and between the mixture layers for a long period of time maintain the conductive network between the electrode substrate and the mixture layer and between the mixture layers even after repeated charging and discharging. Since the charging reaction and the discharging reaction can be performed uniformly, the cycle life characteristics can be improved. In particular, as a transition metal oxide capable of reversibly inserting and releasing lithium ions, a general formula Li _x M
n _y O ₂ (x is 0.2 ≦ x ≦ 2.5, and y is 0.8 ≦ y ≦ 1.
In the organic electrolyte secondary battery using the lithium manganese composite oxide shown in 25) as a positive electrode active material, a non-aqueous solvent-based binder composition exists so as to cover a part of the particle surface of the lithium manganese composite oxide. Therefore, the amount of Mn eluted from the positive electrode active material can be reduced, the electron conductivity of the positive electrode is secured,
On the other hand, the deterioration of the negative electrode due to the eluted Mn can be suppressed, so that an organic electrolyte secondary battery in which the reduction in battery capacity due to charge / discharge cycles is improved is obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a cycle life test result of a non-aqueous electrolyte secondary battery of this example.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shin Nishimura 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Kenji Suzuki 4--13 Higashimachi, Hitachi City, Ibaraki Prefecture 1 Ibaraki Research Laboratory, Hitachi Chemical Co., Ltd. (72) Inventor Kenji Hara 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo F-term in Shin-Kobe Electric Co., Ltd. 4J038 DB002 DB391 DB471 DB491 DH001 EA012 HA216 JB34 MA07 PB09 PC02 5H003 AA02 AA04 AA10 BB05 BB11 BC05 BD00 5H014 AA02 BB03 BB06 BB08 EE01 EE03 EE10 HH00

Claims (6)

[Claims] 1. Diisocyanate or diamine (a)
And a dicarboxylic acid and / or tricarboxylic anhydride (b) in an organic solvent to react with a polyamide resin intermediate (A), an epoxy resin (B) and a polyoxyalkylene monoamine (C). A non-aqueous solvent-based binder composition obtained by dissolving and / or dispersing a binder resin having a component residue (C) in a side chain obtained in the above method. 2. The non-aqueous solvent-based binder composition according to claim 1, comprising a polyfunctional compound and / or a thermoplastic resin. 3. A non-aqueous solvent-based binder composition from which the non-aqueous solvent-based binder composition according to claim 1 or 2 is mixed with an active material, applied to the surface of an electrode substrate, and then the non-aqueous solvent is removed. An electrode characterized in that: 4. The electrode according to claim 3, wherein the active material is capable of reversibly inserting and releasing lithium ions by charging and discharging. Wherein said active material, reversibly inserting lithium ions by charging and discharging, a transition metal oxide capable of releasing, the transition metal oxide is formula Li _x Mn _y O _{0 (x} is 0.2 ≦ x
≤ 2.5, and y is 0.8 ≤ y ≤ 1.25). 6. A non-aqueous solvent-based secondary battery, wherein the electrode according to claim 3, 4 or 5 is used for at least one pole of the non-aqueous solvent-based secondary battery.