TW201832402A - Thickening stabilizer for nonaqueous electrolyte cell electrode, binder composition comprising same, slurry composition for nonaqueous electrolyte cell electrode, nonaqueous electrolyte cell electrode, and nonaqueous electrolyte cell - Google Patents

Abstract

The present invention relates to a thickening stabilizer for a nonaqueous electrolyte cell electrode, the thickening stabilizer containing a polyamine and a neutral salt of an [alpha]-olefin-maleic acid copolymer obtained by copolymerization of an [alpha]-olefin and a maleic acid.

Description

   Viscosity stabilizer for non-aqueous electrolyte battery electrodes, binder composition containing the same, slurry composition for non-aqueous electrolyte battery electrodes, non-aqueous electrolyte battery electrode, and non-aqueous electrolyte battery   

The present invention relates to a viscosity-increasing stabilizer for non-aqueous electrolyte battery electrodes, a binder composition containing the same, a slurry composition for non-aqueous electrolyte battery electrodes, a non-aqueous electrolyte battery electrode, and a non-aqueous electrolyte battery.

In recent years, the popularity of mobile terminals such as mobile phones, notebook personal computers, and pad-type information terminal devices has been very significant. Among secondary batteries used in power sources of these mobile terminals, lithium ion secondary batteries are widely used. Since mobile terminals require more comfortable portability, they have been rapidly developed in miniaturization, thinness, weight reduction, and high performance, and are used in various occasions. This trend is still ongoing, and the battery used in mobile terminals is further required to be smaller, thinner, lighter, and higher performance.

Non-aqueous electrolyte batteries such as lithium ion secondary batteries have a structure in which a positive electrode and a negative electrode are provided with a separator interposed therebetween, and are housed in a container together with an electrolytic solution such as LiPF ₆ and LiBF ₄ Lithium (bistrifluoromethanesulfonyl imide); Lithium (bistrifluoromethanesulfonyl imide)) and LiFSI (lithium difluorosulfonylimide) lithium are dissolved in organic liquids such as ethyl carbonate.

The above-mentioned negative electrode and positive electrode are generally formed by applying a slurry for an electrode (hereinafter, also simply referred to as a slurry) to a current collector, drying the water, and combining them as a mixed layer. The binding agent and the viscosity-increasing stabilizer are dissolved or dispersed in water as an adhesive composition, and are obtained by mixing an active material and a necessary conductive auxiliary agent (conductivity imparting agent). More specifically, for example, in the case of a negative electrode, a carbonaceous material capable of absorbing and releasing lithium ions of an active material, and acetylene black, which is a necessary conductive auxiliary agent, and the like are bonded with a binder for a secondary battery electrode. Current collectors such as copper are combined with each other. On the other hand, the positive electrode is formed by combining LiCoO ₂ and the like, which are active materials, and the same conductive auxiliary agent as the negative electrode, with a secondary battery electrode binder, and a current collector such as aluminum.

Among the technologies so far, as a viscosity-increasing stabilizer for aqueous media, it has been proposed to use methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropoxy cellulose, and carboxymethyl cellulose ‧ sodium Cellulose derivatives such as salts (CMC-Na) (for example, Patent Document 1). Among them, CMC-Na is often used (for example, Patent Document 2).

However, since these cellulose derivatives are insulators, the conductivity between active materials is blocked; or the internal resistance is increased because they do not have Li ion transferability, and a reduction in battery capacity cannot be avoided (Patent Document 3). Recently, the demand for extending the use time of mobile terminals and shortening the charging time has been increasing, and the increase in battery capacity (low resistance), life (cycle characteristics), and charging speed (rate characteristics) have become urgent, especially as an obstacle .

Since it contributes to the increase of resistance, it is a binding agent and a viscosity-increasing stabilizer that are adsorbed on the surface of the active material. In order to reduce the resistance, the amount of the cellulose derivative that suppresses the viscosity-increasing stabilizer is effective. However, when the amount of the viscosity-increasing stabilizer is reduced, the dispersibility of the active substance in the slurry is reduced and agglomerates are generated. Such agglomerates not only promote the reduction of battery capacity, but also form bumps or defects on the coated electrodes. Therefore, not only the electrode yield is reduced, but also Li dendrites, which are the cause of battery short circuits, may significantly damage safety. In addition, since the binding property between the collector and the electrode material and the active material in the electrode is reduced, in addition to the electrode becoming brittle and the electrode yield being reduced, the durability (battery life) for long-term use may be significantly reduced. Therefore, it has hitherto been difficult to reduce the resistance while maintaining the bonding property between the collector and the electrode material.

The present invention has been made in view of the above problems, and its purpose is not to impair the function as a thickening stabilizer, that is, to not impair the dispersibility of the active material, and to improve the binding property with the collector and the non-aqueous electrolyte battery. Reduced battery internal resistance.

Prior art literature Patent literature

Patent Document 1 Japanese Patent Application Publication No. 2008-288214

Patent Document 2 Japanese Patent Application Laid-Open No. 2011-192610

Patent Document 3 Japanese Patent Application Publication No. 2013-257978

As a result of intensive research in order to solve the above-mentioned problems, the present inventors have found that the above-mentioned object is achieved by using a viscosity-increasing stabilizer for a non-aqueous electrolyte battery having the following structure, and further reviewing based on this knowledge, the present invention has been completed.

One form of the viscosity-increasing stabilizer of the present invention is characterized by containing a neutralized salt of an α-olefin-maleic acid copolymer and a polyamine by copolymerizing an α-olefin and a maleic acid.

Forms used to implement the invention

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these.

In this embodiment, the "thickening stabilizer" for non-aqueous electrolyte batteries is not particularly limited. It refers to those that exhibit their functions by dissolving or dispersing in water, and means those having a viscosity region that is adjusted to be suitable for coating. The function of the viscosity modifier and the function of a dispersant to uniformly disperse the active substance in the solvent.

The viscosity-increasing stabilizer for a non-aqueous electrolyte battery according to this embodiment is characterized in that it contains a neutralized salt of an α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid, and a polyamine.

By using the thus constructed non-aqueous electrolyte battery electrode thickening stabilizer, it is possible to obtain a binder composition for a non-aqueous electrolyte battery that does not impair the dispersibility of the active material in the electrode slurry and has binding properties and low resistance. . Furthermore, it is possible to use this to reduce the internal resistance of the non-aqueous electrolyte battery.

In this embodiment, an α-olefin-maleic acid copolymer obtained by copolymerizing an α-olefin and a maleic acid is composed of an α-olefin-based unit (A) and a maleic acid-based unit (B). Each component of (A) and (B) preferably satisfies (A) / (B) = 1/1 to 1/3 (molar ratio). A linear random copolymer having an average molecular weight of 10,000 to 500,000 is preferred.

In the present embodiment, the unit (A) based on α-olefins means the general formula -CH ₂ CR ¹ R ^2- (wherein R ¹ and R ² may be the same or different from each other, indicating hydrogen, Alkyl, alkenyl or aryl, ether, and silyl) having 1 to 10 carbon atoms. The α-olefin used in this embodiment is a linear or branched olefin having a carbon-carbon unsaturated double bond at the α-position. In particular, olefins having a carbon number of 2 to 12 are preferred, and 2 to 8 are particularly preferred. Examples of usable examples include ethylene, propylene, n-butene, isobutene, n-pentene, isoprene, 2-methyl-1-butene, 3-methyl-1-butene, and n-hexane Ene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-butene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethylbutadiene, 2,5-pentadiene, 1,4-hexadiene, 2,2,4-trimethyl-1-pentene, Styrene, α-methylstyrene, p-methylstyrene, methyl vinyl ether, ethyl vinyl ether, and the like. Among these, isobutylene, ethylene, and methyl vinyl ether are particularly preferred from the viewpoints of availability, polymerizability, and stability of the product. Among them, isobutene also includes: a mixture containing isobutene as a main component, such as a BB fraction (C4 fraction). These olefins may be used alone or in combination of two or more.

In this embodiment, as the maleic acid-based unit (B), maleic anhydride; maleic acid; maleic acid monoesters (for example: methyl maleate, ethyl maleate, maleic acid) Maleate, phenyl maleate, etc.), maleate diesters (for example: dimethyl maleate, diethyl maleate, dipropyl maleate, diphenyl maleate, etc.) Etc. maleic anhydride derivatives; maleimide or its N-substituted derivative (for example: maleimide, N-methylmaleimide, N-ethylmaleimide, N -N-substituted alkyl maleates such as -propylmaleimide, N-n-butylmaleimide, N-tertiary butylmaleimide, N-cyclohexylmaleimide, etc. N-substituted alkylphenylmaleimide, fluorenimine, N-phenylmaleimide, N-methylphenylmaleimide, N-ethylphenylmaleimide, etc. Amine, or N-substituted alkoxyphenylmaleimide of N-methoxyphenylmaleimide, N-ethoxyphenylmaleimide, etc.); further, these Halides (eg: N-chlorophenylmaleimide); citraconic anhydride; citraconic acid; citraconic acid monoester (ex: citraconic acid methyl ester) , Ethyl citraconic acid, propyl citraconic acid, phenyl citraconic acid, etc.), citraconic acid diesters (for example: dimethyl citraconic acid, diethyl citraconic acid, dipropyl citraconic acid, Citraconic acid diphenyl ester) and other citraconic anhydride derivatives; citraconic acid or its N-substituted derivative (e.g. citraconic acid, 2-methyl-N-methylmaleimide) , 2-methyl-N-ethylmaleimide, 2-methyl-N-propylmaleimide, 2-methyl-N-n-butylmaleimide, 2-methyl N-substituted alkylmaleimide, 2-methyl-N-tertiary butylmaleimide, 2-methyl-N-cyclohexylmaleimide, 2-methyl-N-phenyl 2-methyl-N-substituted alkanes such as maleimide, 2-methyl-N-methylphenylmaleimide, 2-methyl-N-ethylphenylmaleimide, etc. 2-methyl-N-methoxyphenylmaleimide, 2-methyl-N-methoxyphenylmaleimide, 2-methyl-N-ethoxyphenylmaleimide, etc. -N-substituted alkoxyphenylmaleimide); further, these halides (for example: 2-methyl-N-chlorophenylmaleimide). Among these, maleic anhydride is preferably used from the viewpoints of availability, polymerization rate, and ease of molecular weight adjustment. These maleic acids can be used alone or in combination. As described above, the maleic acid is neutralized by an alkali salt, and the carboxylic acid and carboxylate produced are in the form of 1,2-dicarboxylic acid or salt. This form has the function of replenishing heavy metals dissolved from the positive electrode.

It is desirable that the content ratio of each of the above-mentioned structural units in the copolymer of the present embodiment is in the range of 1/1 to 1/3 in terms of the molar ratio (A) / (B). This is because the advantages of being hydrophilic, water-soluble, and affinity for metals or ions as a high-molecular-weight substance soluble in water can be obtained. In particular, the molar ratio of (A) / (B) is expected to be 1/1 or a value close to it, in which case it becomes a unit having an α-olefin (that is, -CH ₂ CR ¹ R ^2- Copolymers in which the units based on maleic acids are repeated alternately.

The blending ratio of the α-olefins and maleic acid used to obtain the copolymer of this embodiment varies depending on the composition of the standard copolymer. In order to improve the reaction rate of maleic acid, the molar number is maleic acid. Alpha-olefins having 1 to 3 times the mole number are effective.

The manufacturing method of the copolymer of this embodiment is not specifically limited, For example, a copolymer can be obtained by radical polymerization. At this time, as the polymerization catalyst to be used, azo catalysts such as azobisisobutyronitrile, 1,1-azobiscyclohexane-1-carbonitrile, benzamidine peroxide, and diperoxide are preferred. An organic peroxide catalyst such as cumene. The amount of the polymerization catalyst used must be in the range of 0.1 to 5 mole% relative to the maleic acid, and preferably 0.5 to 3 mole%. As a method for adding a polymerization catalyst and a monomer, they may be added together at the initial stage of the polymerization, but a method of gradually adding the polymerization catalyst to the progress of the polymerization is desired.

In the method for producing a copolymer of this embodiment, the adjustment of the molecular weight can be appropriately performed mainly depending on the monomer concentration, the amount of catalyst used, and the polymerization temperature. For example, it is also possible to use an amine represented by a salt, hydroxide, group IV metal halide, general formula N≡, HN =, H ₂ N- or H ₄ N- Nitrogen compounds such as ammonium acetate, ammonium acetate, and urea, or mercaptans, etc., are added to reduce the molecular weight at the initial stage of polymerization or during the polymerization to adjust the molecular weight of the copolymer. The polymerization temperature is preferably in the range of 40 ° C to 150 ° C, and more preferably in the range of 60 ° C to 120 ° C. When the polymerization temperature is too high, the resulting copolymer is likely to become agglomerate, and the polymerization pressure may be significantly increased. The polymerization time is generally preferably about 1 to 24 hours, and more preferably 2 to 10 hours. The amount of the polymerization solvent used is preferably 5 to 40% by weight of the obtained copolymer, and more preferably adjusted to be 10 to 30% by weight.

As described above, the copolymer of this embodiment generally has an average molecular weight of 10,000 to 500,000. A more preferable average molecular weight is 15,000 to 450,000. When the average molecular weight of the copolymer of this embodiment is less than 10,000, there is a possibility that the crystallinity is high and the adhesion strength between particles is reduced. On the other hand, when it exceeds 500,000, the solubility to water or a solvent may become small and it may precipitate easily.

The average molecular weight of the copolymer of this embodiment can be measured by, for example, a light scattering method or a viscosity method. When the limiting viscosity ([η]) in dimethylformamide is measured using a viscosity method, the limiting viscosity of the copolymer of this embodiment is preferably in a range of 0.05 to 2. In addition, the copolymer of this embodiment is usually obtained in a uniform powder form with particles of about 16 to 60 meshes.

In this embodiment, it is preferable that the neutralization salt of the copolymer is an active hydrogen of a carboxylic acid generated from maleic acids and an alkaline substance to form a salt and become a neutralizer. In the neutralized α-olefin-maleic acid copolymer used in the present embodiment, it is preferable to use a basic substance containing a monovalent metal and / or ammonia from the viewpoint of binding properties. .

The degree of neutralization is not particularly limited, but when used as a binder, considering the reactivity with the electrolyte, it is generally 1 mole, preferably 0.3 to 1 mole, relative to the carboxylic acid generated from maleic acids. The range of ears is more preferably neutralized in the range of 0.4 to 1 mole. With such a degree of neutralization, the pH of the adhesive composition of this embodiment can be adjusted to a predetermined range, and has the advantage of being low in acidity and inhibiting decomposition of the electrolytic solution.

In this embodiment, a method such as titration with an alkali, infrared spectrum, and NMR spectrum can be used for the degree of neutralization. In order to easily and accurately measure the neutralization point, titration with an alkali is preferable. The specific titration method is not particularly limited, and it can be carried out by neutralizing an alkaline substance such as lithium hydroxide, sodium hydroxide, potassium hydroxide, and the like with a small amount of impurities dissolved in ion-exchanged water and the like. The indicator of the neutralization point is not particularly limited, and an indicator such as phenolphthalein that expresses pH by a base can be used.

In this embodiment, the usage amount of the alkaline substance containing a monovalent metal and / or ammonia is not particularly limited, and it is appropriately selected depending on the purpose of use and the like. Usually, it is preferably a maleic acid unit in a maleic acid copolymer. The amount is 0.1 to 2 moles per mole. If it is such an amount used, it can be considered that the pH of the adhesive composition of this embodiment can be adjusted to a predetermined range. In addition, it is preferable that the amount of the basic substance containing a monovalent metal is 0.6 to 2.0 mol per maleic acid unit in the maleic acid-based copolymer, and more preferably 0.7 to 2.0. In the case of a molar amount, the alkali residue is small, and a water-soluble copolymer salt can be obtained.

The reaction of an α-olefin-maleic acid copolymer with an amine such as a basic substance containing a monovalent metal and / or ammonia can be carried out according to a conventional method, and an α-olefin as an aqueous solution can be obtained in the presence of water. -The method of neutralizing the maleic acid copolymer is simple and preferable.

Examples of the alkaline substance containing a monovalent metal that can be used in this embodiment include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; and alkali metals such as sodium carbonate and potassium carbonate. Carbonate; sodium acetate, potassium acetate and other alkali metal acetates; trisodium phosphate and other alkali metal phosphates. Examples of the amines such as ammonia include primary amines such as ammonia, methylamine, ethylamine, butylamine, and octylamine; secondary amines such as dimethylamine, diethylamine, and dibutylamine; and trimethylamine and triethyl Tertiary amines such as amines, tributylamine, etc .; polyamines such as ethylenediamine, butylenediamine, diethyleneimine, triethyleneimine, polyethyleneimine, etc. Among these, ammonia, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferred. Especially as a binder for lithium ion secondary batteries, ammonia and lithium hydroxide are preferably used. The alkaline substance and / or ammonia containing a monovalent metal may be used alone or in combination of two or more kinds. If it does not adversely affect the battery performance, an alkaline substance such as a hydroxide of an alkali metal such as sodium hydroxide may be used together to prepare an α-olefin-maleic acid copolymer. And things.

Next, in the present embodiment, the ring opening rate of the copolymer indicates the hydrolysis rate of the maleic anhydride site polymerized with the α-olefin when maleic anhydride is used as the maleic acid. In the copolymer of this embodiment, the preferred ring opening rate is 60 to 100%, more preferably 70% to 100%, and even more preferably 80% to 100%. When the ring opening ratio is too low, the degree of freedom of the structure of the copolymer becomes small, and the stretchability becomes insufficient. Therefore, there is a risk that the adhesion force of the following polar material particles becomes small, which is not preferable. Furthermore, there is a possibility that problems such as low affinity for water and lack of solubility may arise. The ring-opening ratio can be determined by, for example, measuring the hydrogen at the α-position of the ring-opened maleic acid by 1H-NMR based on the hydrogen at the α-position of maleic anhydride. The carbonyl group derived from the ring-opened maleic anhydride was determined by IR measurement to determine the ratio.

In this embodiment, when the maleic acid is maleic anhydride, the active hydrogen of the carbonyl acid generated by the ring-opening of the salt-based maleic anhydride in the copolymer reacts with the basic substance as described above to form a salt. Neutralizer. The degree of neutralization at this time is not particularly limited. When used as a viscosity-increasing stabilizer, considering the reactivity with the electrolyte, it is generally 0.5 moles relative to the carbonyl acid generated by ring opening, preferably 0.5. In the range of ~ 1 mole, it is more preferable to use a neutralizer in the range of 0.6 ~ 1 mole. With such a degree of neutralization, there is an advantage that the acidity is low and decomposition of the electrolytic solution is suppressed. The degree of neutralization of the copolymer when maleic anhydride is used can be measured by the same method as the method described above.

In addition to the copolymer neutralization salt, the viscosity-increasing stabilizer of this embodiment also contains polyamines to form a crosslinked structure. Bondability can be imparted by crosslinking.

The polyamines used in this embodiment are not limited as long as they are electrochemically stable, and examples thereof include low molecular weight bodies having a molecular weight of less than 300 and / or high molecular weight bodies having a molecular weight of 300 or more.

Specific examples of the polyamine-based low molecular weight body include aliphatic polyamines, aromatic polyamines, and heterocyclic polyamines. Preferred specific examples include aliphatic polyamines such as ethylenediamine, hexamethylenediamine, ethylenediamine, triethylenetetramine, and guanidine; and aromatic polyamines such as phenylenediamine Class N-aminoethyl piperazine Heterocyclic polyamines and the like.

Specific examples of the polyamine-based high-molecular weight body include an amine group-containing polymer, and preferred specific examples thereof include polyethyleneimine, polytetramethyleneimine, polyvinylamine, Polyallylamine, dicyandiamine-formalin condensate, dicyandiamine-alkylene (polyamine) condensate, and the like. These can be used alone or in combination. In consideration of obtaining a family name and economy, it is preferable to use polyethyleneimine.

The molecular weight of these polyamines is not particularly limited. The average molecular weight is in the range of 50 to 200,000, more preferably in the range of 100 to 180,000, and most preferably in the range of 200 to 100,000.

The amount of polyamines added to the viscosity-increasing stabilizer of the present embodiment is not particularly limited, but it is generally from 0.01 parts by weight to 100 parts by weight of the α-olefin-maleic copolymer (solid content). A range of 10 parts by weight, more preferably a range of 0.02 to 6 parts by weight. An excessive addition amount is not preferable because it forms a salt with the α-olefin-maleic acid copolymer, gels with strength by multi-crosslinking, and restricts moisture violently, making it difficult to dry. On the other hand, an excessively small amount of addition is not preferable because sufficient bonding properties cannot be provided.

In this embodiment, the polyamines may be added while the α-olefin-maleic acid copolymer is reacted with a basic substance containing a monovalent metal, or the α-olefin-maleic acid copolymer and the Valence metal basic substance is added after reaction. Generally, the temperature for promoting the crosslinking reaction is not particularly limited, and the crosslinking reaction proceeds rapidly by heating at 20 ° C or higher, preferably 30 ° C or higher. The time required for the cross-linking reaction to converge is not limited because it depends on the temperature, and the cross-linking reaction usually converges in about 0.1 hours to 2 months.

The viscosity of the viscosity-increasing stabilizer in this embodiment is in the range of 100 to 30,000 cP, and more preferably in the range of 1000 to 10,000 cP. At a viscosity below 100 cP, the coating viscosity is greatly deteriorated due to the drastic reduction of the viscosity of the slurry. In addition, at a viscosity of 30,000 cP or more, when the slurry is adjusted, the wettability of the active material or the conductive additive is poor, and the dispersibility of the active material or the conductive additive in the slurry is greatly reduced.

Next, a binder composition for a non-aqueous electrolyte battery electrode according to this embodiment will be described. The adhesive composition generally includes the viscosity-increasing stabilizer and the particulate bonding agent according to the embodiment.

The particulate binding agent that can be used in this embodiment is not particularly limited as long as it is granular and has mutual binding properties to an active material and / or a current collector described later. Examples of a preferable particulate binder include a dispersion-type binder having excellent dispersibility in a dispersion medium. Specific examples of the dispersion-type binding agent include a fluorine-based polymer, a diene-based polymer, an ethylene aromatic and conjugated diene random or block copolymer, an acrylic polymer, a polyimide, and a polymer. Polymer compounds such as amidine and polyurethane polymers.

A diene polymer is a homopolymer of a conjugated diene, or a random or block copolymer obtained by polymerizing a monomer mixture containing ethylene aromatic or conjugated diene, or a hydride thereof. Specific examples of the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene, and styrene-butadiene copolymers (SBR) which can be modified by carboxyl groups. And other aromatic vinyl ‧ conjugated diene copolymers; acrylonitrile ‧ butadiene copolymers (NBR) and other cyanide ethylene conjugated diene copolymers; hydrogenated SBR, hydrogenated NBR, etc.

The acrylic polymer is a homopolymer of an acrylate or a methacrylate, or a copolymer with a monomer copolymerizable therewith. Examples of the copolymerizable monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, Trimethylolpropane triacrylate and other carboxylic acid esters with more than two carbon-carbon double bonds; styrene, chlorostyrene, vinyltoluene, tertiary butylstyrene, vinylbenzoic acid, vinyl Styrene-based monomers such as methyl benzoate, vinylnaphthalene, chloromethylstyrene, methylolstyrene, α-methylstyrene, and divinylbenzene; acrylamide, N-methylolpropene Ammonium monomers such as ammonium amine and acrylamine-2-methylpropanesulfonic acid; α, β-unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile; olefins such as ethylene and propylene; butadiene Diene monomers such as olefin, isoprene, etc .; halogen atom-containing monomers such as vinyl chloride, vinylidene chloride; etc .; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, etc. Vinyl esters; methyl vinyl ethers, ethyl vinyl ethers, butyl vinyl ethers and other vinyl ethers; methyl Vinyl ketones such as vinyl ketone, ethyl vinyl ketone, butyl vinyl ketone, hexyl vinyl ketone, isopropenyl vinyl ketone, etc .; N-vinyl pyrrolidone, vinyl pyridine, vinyl imidazole, etc. Heterocyclic-containing vinyl compounds; β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, and the like containing hydroxyalkyl compounds.

Among these, an acrylic monomer, SBR, NBR, and hydrogenated SBR are preferably used, and an acrylic monomer, SBR, and hydrogenated SBR are more preferably used.

In addition, in the binder of the present embodiment, "particles" means polymer particles obtained by subjecting the monomers constituting the polymer to emulsion polymerization, or polymer particles emulsified and emulsified after polymerization. It does not specifically limit as an emulsion polymerization method, What is necessary is just to employ the conventionally well-known emulsion polymerization method. The particle size of the particulate binder is preferably 0.01 to 0.5 μm, and more preferably 0.01 to 0.3 μm. When the particle diameter is 0.01 μm or less, the viscosity of the slurry is significantly increased and the coatability is deteriorated. When the particle diameter is 0.5 μm or more, the dispersibility of the adhesive in the electrode decreases, and the adhesiveness decreases.

In addition, in the binder of this embodiment, a protective colloid may be added in order to stabilize the polymer particles. The protective colloid system used in the present invention refers to a hydrophilic colloid added for the purpose of stabilizing a hydrophobic colloid to an electrolyte. The stabilization effect is considered to be due to the fact that the hydrocolloid particles surround the hydrocolloid particles and thus exhibit the properties of the hydrocolloid as a whole. Examples of the protective colloid include polyvinyl alcohol, modified polyvinyl alcohol; water-soluble cellulose derivatives such as methyl cellulose, ethyl cellulose, methylol cellulose, and hydroxypropyl cellulose; Group) water-soluble salts of acrylate-unsaturated carboxylic acid-based copolymers; styrene-maleic anhydride copolymer salts, maleated polybutadiene salts, naphthalenesulfonates, polyacrylates, and the like. These protective colloids may be used singly or in combination of two or more kinds. Among these, as the protective colloid, a water-soluble salt of (meth) acrylate-unsaturated carboxylic acid copolymer and / or polyvinyl alcohol is preferably used, and (meth) acrylic acid is particularly preferably used as the protective colloid. A water-soluble salt of an ester-unsaturated carboxylic acid copolymer.

The adhesive composition for a non-aqueous electrolyte battery of the present embodiment is preferably used as a slurry composition (hereinafter, also simply referred to as a slurry composition) for a non-aqueous electrolyte battery electrode, which is a non-aqueous electrolyte battery. The slurry composition for electrodes generally contains an active material and water in addition to the above-mentioned binder composition. That is, the slurry composition of this embodiment contains the viscosity-increasing stabilizer and particulate binder, the active material, and water, and the protective colloid that stabilizes polymer particles as necessary.

In this embodiment, the non-aqueous electrolyte battery electrode is characterized in that a mixed layer including at least the binder composition and the active material of this embodiment is bonded to a current collector. This electrode can be formed by applying the above-mentioned slurry composition to an electrode, and then removing the solvent by a method such as drying. A conductive auxiliary agent and the like may be further added to the mixed layer as necessary.

In the above slurry composition for a non-aqueous electrolyte battery, the amount of the thickening stabilizer is generally preferably 0.1 to 4 parts by weight, more preferably 0.3 to 3 parts by weight, and even more preferably 100 parts by weight of the active material. 0.5 ~ 2 parts by weight. When the amount of the thickening stabilizer is too small, the viscosity of the slurry is too low and the thickness of the mixed layer may be reduced. On the contrary, when the amount of the thickening stabilizer is excessive, the discharge capacity may be reduced.

The amount of the particulate binder in the slurry composition is generally preferably 0.1 to 4 parts by weight, and more preferably 0.1 to 2 parts by weight based on 100 parts by weight of the active material. When the amount of the particulate binding agent is too large, the internal resistance of the battery may increase. On the other hand, when the amount is too small, the binding property is significantly reduced.

As the solvent in the negative electrode slurry composition of this embodiment, in addition to the above water, alcohols such as methanol, ethanol, propanol, 2-propanol, and the like can also be used; tetrahydrofuran, 1,4-di Cyclic ethers such as alkanes; N, N-dimethylformamide, N, N-dimethylacetamide and other amines; N-methylpyrrolidone, N-ethylpyrrolidone And other cyclic amidines; dimethylarylene and the like. Among these, from the viewpoint of safety, it is preferable to use water.

As the solvent of the slurry composition for a negative electrode of the present embodiment, in addition to the water described above, the organic solvent described below can be used in a range of preferably 20% by weight or less as the entire solvent. As such an organic solvent, those having a boiling point of 100 ° C. to 300 ° C. under normal pressure are preferred, and examples thereof include hydrocarbons such as n-dodecane; 2-ethyl-1-hexanol, 1-nonanol Alcohols such as γ-butyrolactone, methyl lactate, etc .; N-methylpyrrolidone, N, N-dimethylacetamide, dimethylformamide, etc. Organic dispersing media such as dimethyl sulfene and cyclobutane.

When the slurry composition of this embodiment is used for a negative electrode, as a negative electrode active material (also referred to as an active material for short) added to the slurry composition for a negative electrode, examples are: amorphous carbon, graphite, Carbonaceous materials such as natural graphite, mesocarbon microbeads (MCMB), pitch-based carbon fibers; conductive polymers such as polyacene; composites shown by SiO _x , SnO _x , and LiTiO _x Metal oxides, other metal oxides, or lithium-based metals such as lithium metals and lithium alloys; metal compounds such as TiS ₂ and LiTiS ₂ .

In this embodiment, a thickener may be further added to the slurry composition as necessary. The tackifier that can be added is not particularly limited, and various alcohols (especially polyvinyl alcohol and modified products thereof), celluloses, and polysaccharides such as starch can be used.

The amount of the thickener to be blended in the slurry composition as necessary is preferably about 0.1 to 4 parts by weight, more preferably 0.3 to 3 parts by weight, and even more preferably 0.5 to 100 parts of the negative electrode active material. ~ 2 parts by weight. When the amount of the thickening agent is too small, the viscosity of the slurry for the negative electrode of the secondary battery may be too low and the thickness of the mixed layer may be reduced. On the other hand, when the amount of the thickening agent is too large, the discharge capacity may be reduced.

Examples of the conductive auxiliary agent to be blended in the slurry composition as necessary include metal powder, conductive polymer, and acetylene black. The amount of the conductive additive used is generally preferably 0.5 to 10 parts by weight, and more preferably 1 to 7 parts by weight relative to 100 parts by weight of the negative electrode active material.

The current collector used in the non-aqueous electrolyte battery electrode of this embodiment is not particularly limited as long as it is made of a conductive material. When it is a negative electrode, for example, iron, copper, aluminum, nickel, stainless steel, and titanium can be used. , Tantalum, gold, platinum and other metal materials. These can be used alone or in combination of two or more at any ratio.

In particular, when copper is used as the negative electrode, the effect of the slurry for a non-aqueous electrolyte battery electrode of the present invention is most exhibited. The shape of the current collector is not particularly limited, and generally a sheet shape having a thickness of about 0.001 to 0.5 mm is preferred.

The method for applying the slurry to the current collector is not particularly limited. Examples of the method include a doctor blade method, an immersion method, a reverse roll method, a direct roll method, a gravure printing method, an extrusion method, a dipping method, and a brush coating method. The coating amount is also not particularly limited, and it is generally preferred that the thickness of the mixed layer including the active material, the conductive auxiliary agent, the binder, and the thickener formed after removal by a method such as drying a solvent or a dispersion medium becomes 0.005 The amount of ~ 5mm is more preferably 0.01 ~ 2mm.

The drying method of the solvent such as water contained in the slurry composition is not particularly limited, and examples include: ventilation drying using warm air, hot air, and low-humidity wind; vacuum drying; infrared, far infrared, and electron beam radiation Line drying and so on. The drying conditions may be adjusted within a speed range in which cracks are not formed in the active material layer due to stress concentration or the active material layer does not peel from the current collector, so that the solvent can be removed as quickly as possible. Furthermore, in order to increase the density of the active material of the electrode, it is effective to press the dried current collector. Examples of the pressing method include methods such as die pressing and roll pressing.

The present invention also includes a non-aqueous electrolyte battery having the above-mentioned negative electrode. In a nonaqueous electrolyte battery, when the electrode of this embodiment is used as a negative electrode, the negative electrode, the positive electrode, and the electrolytic solution are generally included.

In this embodiment, the positive electrode is a positive electrode generally used in a non-aqueous electrolyte battery such as a lithium ion secondary battery without particular limitation. For example, as the positive electrode active material, TiS ₂ , TiS ₃ , amorphous MoS ₃ , Cu ₂ V ₂ O ₃ , amorphous V ₂ OP ₂ O ₅ , MoO ₃ , V ₂ O ₅ , V ₆ O _{13 are used.} And other transition metal oxides or lithium-containing composite metal oxides such as LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , and LiMn ₂ O ₄ . The positive electrode active material, the same conductive additive as the negative electrode, and SBR, NBR, acrylic rubber, and hydroxyethyl fiber can be mixed in water or a solvent having a boiling point of 100 ° C to 300 ° C under the normal pressure. A positive electrode slurry prepared by a binder such as cellulose, carboxymethyl cellulose, polyvinylidene fluoride, and the like is applied to a positive electrode current collector such as aluminum, and the solvent is dried to form a positive electrode.

In the non-aqueous electrolyte battery of this embodiment, an electrolytic solution obtained by dissolving an electrolyte in a solvent can be used. If the electrolytic solution is used by a general non-aqueous electrolyte battery such as a lithium ion secondary battery, it may be in a liquid state or a gel state, as long as it is appropriately selected and used as a battery according to the type of the negative electrode active material and the positive electrode active material. The person with the function is sufficient. As a specific electrolyte, for example, any one of conventionally known lithium salts may be used, and examples thereof include LiClO ₄ , LiBF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , and LiB ₁₀ Cl. ₁₀ , LiAlCl ₄ , LiCl, LiBr, LiB (C ₂ H ₅ ) ₄ , CF ₃ SO ₃ Li, CH ₃ SO ₃ Li, LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, lower aliphatic lithium carboxylate and the like.

The solvent (electrolyte solvent) that dissolves such an electrolyte is not particularly limited. Specific examples include carbonates such as propylene carbonate, ethyl carbonate, butyl carbonate, dimethyl carbonate, and diethyl carbonate; lactones such as γ-butyrolactone; and trimethoxy Ethers such as methylmethane, 1,2-dimethoxyethane, diethyl ether, 2-ethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, and the like; Oxycyclopentane (oxolane) such as 3-dioxolane, 4-methyl-1,3-dioxolane; Nitrogen compounds such as acetonitrile or nitromethane; formic acid formate Esters, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate and other organic acid esters; triethyl phosphate, dimethyl carbonate, diethyl carbonate and other inorganic acid esters ; Diglyme; Triglyme; Cyclobutadiene; 3-Methyl-2- Azolidone Oxazolidinones; sultones such as 1,3-propanesultone, 1,4-butanesultone, naphthalenesultone, etc. These can be used alone or in combination Used above. When a gel-like electrolytic solution is used, a nitrile polymer, an acrylic polymer, a fluorine polymer, an alkylene oxide polymer, or the like can be added as a gelling agent.

The method for manufacturing the non-aqueous electrolyte battery of this embodiment is not particularly limited, and examples thereof include the following manufacturing methods. That is, the negative electrode and the positive electrode are overlapped with each other through a separator such as a polypropylene porous film, and are rolled, folded, or the like according to the shape of the battery, put into a battery container, filled with an electrolytic solution, and sealed. The shape of the battery may be any of a well-known coin type, a button type, a sheet type, a cylindrical type, a square type, and a flat type.

The non-aqueous electrolyte battery of the present embodiment is a battery that is compatible with the improvement of adhesion and battery characteristics, and is used in various applications. For example, it is also very useful as a battery used in a mobile terminal that requires miniaturization, thinness, weight reduction, and high performance.

This specification discloses various aspects of the techniques described above, and summarizes the main techniques among them as follows.

One form of the viscosity-increasing stabilizer of the present invention is characterized by containing a neutralized salt of an α-olefin-maleic acid copolymer and a polyamine, which are copolymerized by α-olefins and maleic acid.

With such a configuration, it is possible to improve the binding property with the collector and reduce the internal resistance of the non-aqueous electrolyte battery without impairing the dispersibility of the active material in the electrode slurry.

In addition, according to another aspect of the present invention, a non-aqueous electrolyte battery electrode binder solution is characterized in that it contains the above-mentioned viscosity-increasing stabilizer and particulate binder.

In addition, the slurry composition for a non-aqueous electrolyte battery electrode according to another aspect of the present invention includes the above-mentioned binder composition for a non-aqueous electrolyte battery electrode, an active material, and a solvent.

The non-aqueous electrolyte battery electrode according to another aspect of the present invention is characterized in that a mixed layer containing at least the above-mentioned binder composition for a non-aqueous electrolyte battery electrode and an active material is bonded to a current collector.

A nonaqueous electrolyte battery according to another aspect of the present invention includes the nonaqueous electrolyte battery electrode described above.

    [Example]    

Hereinafter, examples will be described, but the present invention is not limited thereto.

    (Example 1)         <Viscosity stabilizer for negative electrode>    

As a thickening stabilizer for the negative electrode, a lithium-modified isobutylene-maleic anhydride copolymer resin (average molecular weight 325,000, degree of neutralization 0.5, ring opening rate 96%), a 10% by weight aqueous solution, and polyethyleneimine (PEI, Wako Pure Chemical Industries, Ltd. (average molecular weight: 10,000) 10% by weight aqueous solution was mixed so that the weight ratio was 99: 1 (solid content: resin: PEI = 6.387: 0.065). The resulting mixture was warmed to 90 ° C and heated with stirring for 2 hours. Then, water was added to the obtained mixed solution so that the solid content concentration became 5.5% by weight, and the mixture was uniformly stirred at a rotation speed of 3,600 rpm for 2 hours using a mixer mill to obtain a thickening stabilizer.

    <Production of slurry for negative electrode>    

The electrode slurry is produced in a special container, and 100% by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode is charged with 2.08 parts by weight of a solid binder as a particulate binder. TRD2001 (SBR, manufactured by JSR), the above-mentioned viscosity-increasing stabilizer at 1.04 parts by weight in terms of solid content, and Super-P (Timcal) as a conduction aid (conductivity imparting agent) at 1.04 parts by weight in terms of solid content Co., Ltd.), using a planetary mixer (ARE-250, manufactured by Thinky). In order to adjust the viscosity of the slurry, water was added during the kneading, and kneading was performed again to prepare a slurry for electrode coating. The composition ratio of the active substance and the binder in the slurry is graphite powder in terms of solid content: conductive additive: binder composition = 100: 1.04: 3.12.

    <Production of negative electrode for battery>    

The obtained slurry was applied to a copper foil (CST8G, Fukuda Metal Foil Industrial Co., Ltd.) of a current collector using a bar coater (T101, manufactured by Matsuo Industry Co., Ltd.), and heated at 80 ° C with a hot air dryer (manufactured by Yamato Scientific) After performing primary drying for 30 minutes, a rolling process was performed using a roll press (manufactured by Hohsen). Then, after punching as an electrode for a battery (φ 14 mm), a coin-type battery electrode was produced by secondary drying under reduced pressure at 120 ° C for 3 hours.

    <Toughness test of electrode>    

The electrode toughness evaluation is based on JIS K5600-5-1 (General Test Method for Coatings-Part 5: Mechanical Properties of Coating Films-Section 1: Bending Resistance (Cylinder Mandrel Method)) get on. The electrode rupture was confirmed visually, and the results of the minimum mandrel diameter at which no rupture occurred were shown in Table 1 below. In addition, the smaller the toughness mandrel diameter is, the higher the diameter is. If it is 5 mm or less, it is suitable for use as an electrode.

    <Measurement of peeling strength of electrode>    

The strength when the electrode was peeled from the copper foil of the collector was measured. The peel strength was measured at a 180 ° peel strength using a 50 N dynamometer (manufactured by Imada Co., Ltd.). The slurry-coated surface of the battery-coated electrode obtained above was bonded to a stainless steel plate using a double-sided tape (double-sided tape made by Nichiban), and the 180 ° peel strength (peel width 10 mm, peel speed 100 mm / minute) was measured. The results are shown in Table 1 below.

    <Making a Battery>    

The coated electrode for a battery obtained as described above was transferred to a glove box (manufactured by Miwa Co., Ltd.) under an argon atmosphere. As the positive electrode system, a metal lithium foil (thickness: 0.2 mm, φ 16 mm) was used. Polypropylene (Celguard # 2400, manufactured by Polypore) was used as the separator, and lithium hexafluorophosphate (LiPF ₆ ) was used as the electrolyte. Ethyl carbonate (EC) and ethyl methyl carbonate (EMC) were added. A mixed solvent system of vinyl ester (VC) (1M-LiPF ₆ , EC / EMC = 3 / 7vol%, VC 2% by weight) was injected to make a coin-type battery (type 2032).

    <Evaluation method: Charging and discharging characteristics test>    

The produced coin-type battery was subjected to a charge-discharge test using a commercially available charge-discharge tester (TOSCAT3100, manufactured by TOYO SYSTEM). The coin-type battery was placed in a 25 ° C constant temperature bath, and the charging system was charged at a constant current of 0.1C (about 0.5 mA / cm ² ) with respect to the mass of the active material until the potential of the lithium reached 0V, and then the 0V was further implemented. The voltage was charged until a current of 0.02 mA relative to the lithium potential. The capacity at this time was taken as the charging capacity (mAh / g). Next, discharge was performed at a constant current of 0.1 C (about 0.5 mA / cm ² ) to 1.5 V with respect to the lithium potential, and the capacity at this time was taken as the discharge capacity (mAh / g). The difference between the initial discharge capacity and the charge capacity is taken as the irreversible capacity, and the percentage of the discharge capacity / charge capacity is taken as the charge and discharge efficiency. The DC resistance of coin-type batteries is the resistance value after one charge (in a fully charged state). The results are shown in Table 1 below.

    (Example 2)    

In a special container, TRD2001 (SBR, manufactured by JSR), which is a particulate binder, was added in an amount of 2.08 parts by weight with respect to 100 parts by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode. In terms of solid content, 1.56 parts by weight of the same thickening stabilizer as in Example 1, and in terms of solid content, 1.04 parts by weight of Super-P (manufactured by Timcal) as a conductive additive (conductivity imparting agent). Using a planetary mixer (ARE-250, manufactured by Thinky). In order to adjust the viscosity of the slurry, water was added during the kneading, and kneading was performed again to prepare a slurry for electrode coating. Then, a coated electrode was prepared by the same method as in Example 1 above, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Example 3)    

In a special container, TRD2001 (SBR, manufactured by JSR), which is a particulate binder, was added in an amount of 2.08 parts by weight with respect to 100 parts by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode. 2.08 parts by weight of the solid content of the viscosity-increasing stabilizer of Example 1 and 1.04 parts by weight of the solid content of Super-P (manufactured by Timcal) as a conductive additive (conductivity imparting agent) were used. Planetary mixer (ARE-250, manufactured by Thinky) was kneaded. In order to adjust the viscosity of the slurry, water was added during the kneading, and kneading was performed again to prepare a slurry for electrode coating. Then, a coated electrode was produced by the same method as in Example 1 above, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Example 4)    

As a thickening stabilizer for the negative electrode, a lithium-modified methyl vinyl ether-maleic anhydride copolymer resin (average molecular weight 630,000, degree of neutralization 0.5, ring opening rate 98%), 10% by weight aqueous solution and polyethylene glycol A 10% by weight aqueous solution of amine (PEI, manufactured by Wako Pure Chemical Industries, Ltd., with an average molecular weight of 10,000) was mixed at a weight ratio of 99: 1 (resin in terms of solid content: PEI = 6.387: 0.065). The resulting mixture was warmed to 90 ° C and heated with stirring for 2 hours. Then, water was added to the obtained mixed solution so that the solid content concentration became 5.5% by weight, and the mixture was uniformly stirred at a rotation speed of 3,600 rpm for 2 hours using a mixing mill. Then, a slurry and a coated electrode were produced by the same method as in Example 1 above, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Example 5)    

As a thickener for the negative electrode, a lithium-modified ethylene-maleic anhydride copolymer resin (average molecular weight 100,000, degree of neutralization 0.5, ring opening rate 99%), a 10% by weight aqueous solution, and polyethyleneimine (PEI, Made by Wako Pure Chemical Industries, Ltd., with an average molecular weight of 10,000). A 10% by weight aqueous solution is mixed so that the weight ratio becomes 99: 1 (solid content: resin: PEI = 6.387: 0.065). The resulting mixture was warmed to 90 ° C and heated with stirring for 2 hours. Then, water was added to the obtained mixed solution so that the solid content concentration became 5.5% by weight, and the mixture was uniformly stirred at a rotation speed of 3,600 rpm for 2 hours using a mixing mill. Then, in the same manner as in Example 1, a slurry-coated electrode was produced, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Example 6)         <Particulate Binding Agent>    

In a stirring tank with a homogenizer with a capacity of 1 liter, 15 g of polyvinyl alcohol (trade name, manufactured by Kuraray Co., Ltd., POVAL 405 (degree of polymerization: 500, degree of saponification: 81.5%)) was sequentially added, and 300 g of toluene was dissolved. Hydrogenated block copolymer (SEPTON 2002 (trade name, manufactured by Kuraray Co., Ltd., hydrogenated product of styrene-isoprene-styrene triblock copolymer, 30% styrene content) 150 g, water 500 g, room temperature Then, the mixture was stirred at 15,000 rpm for 10 minutes, and then transferred to a pressure homogenizer for emulsification. Toluene and water were distilled off from the obtained dispersion solution under reduced pressure heating (60 ° C) using a rotary evaporator to obtain an average. Aqueous emulsion having a particle size of 0.3 μm.

    <Production of slurry for negative electrode>    

The slurry for the electrode is produced in a dedicated container, and the above-mentioned particulate binder in an amount of 2.08 parts by weight in terms of solid content is added to 100 parts by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode. 1.04 parts by weight of the solid content was the same thickening stabilizer as in Example 1, and 1.04 parts by weight of the solid content of Super-P (manufactured by Timcal) as a conductive additive (conductivity imparting agent), Use a planetary mixer (ARE-250, manufactured by Thinky) to knead. In order to adjust the viscosity of the slurry, water was added during the kneading, and kneading was performed again to prepare a slurry for electrode coating. Then, a coated electrode was produced by the same method as in Example 1 above, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Comparative example 1)    

As a thickening stabilizer for the negative electrode, a lithium-modified isobutylene-maleic anhydride copolymer resin (average molecular weight 325,000, degree of neutralization 0.5, and ring opening rate 96%) was used as a 10% by weight aqueous solution, and was the same as in Example 1 The method was used to make a slurry and coated electrode, and conduct toughness test and peel strength measurement. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Comparative example 2)    

In a special container, TRD2001 (SBR, manufactured by JSR), which is a particulate binder, was added in an amount of 2.08 parts by weight with respect to 100 parts by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode. 1.08 parts by weight of carboxymethylcellulose as a viscosity-increasing stabilizer in terms of solid content, and Super-P (manufactured by Timcal Co., Ltd.) as a conductive aid (conductivity imparting agent) in terms of solid content of 1.04 parts by weight ), Using a planetary mixer (ARE-250, manufactured by Thinky). In order to adjust the viscosity of the slurry, water was added during the kneading, and kneading was performed again to prepare a slurry for electrode coating. Then, a coated electrode was produced by the same method as in Example 1 above, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Comparative example 3)    

In a special container, TRD2001 (SBR, manufactured by JSR), which is a particulate binder, was added in an amount of 2.08 parts by weight with respect to 100 parts by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode. 1.08 parts by weight of hydroxyethyl cellulose as a viscosity-increasing stabilizer in terms of solid content, and Super-P (manufactured by Timcal Corporation) as a conductive aid (conductivity imparting agent) in terms of solid content of 1.04 parts by weight ), Using a planetary mixer (ARE-250, manufactured by Thinky). In order to adjust the viscosity of the slurry, water was added during the kneading, and kneading was performed again to prepare a slurry for electrode coating. Then, a coated electrode was produced by the same method as in Example 1 above, and a toughness test and peel strength measurement were performed. Furthermore, a coin-type battery using the electrode was obtained, and a charge-discharge characteristic test was performed. The results of these evaluations are shown in Table 1.

    (Inspection)    

Compared with Comparative Examples 2 to 3 using cellulose derivatives, Examples 1 to 6 and Comparative Example 1 have low resistance. It is considered that this is because the structures of Examples 1 to 6 and Comparative Example 1 have dicarboxylic acid units, so that Li ions jump through the carboxylic acid group, and Li ion conductivity is exhibited. In addition, regarding the bonding property, the heights of Examples 1 to 6 are higher than those of Comparative Examples 1 to 3. It is considered that this is due to the cross-linking by a polyamine, and that the polymer alone has superior binding properties compared to cellulose derivatives. From the above, it is shown that by using the viscosity-increasing stabilizer of the present invention, excellent binding properties and resistance reduction can be achieved.

This application is based on Japanese Patent Application Japanese Patent Application No. 2017-005051 filed on January 16, 2017 and Japanese Patent Application No. 2017-094146 filed on May 10, 2017, the contents of which are included in this application in.

In order to express the present invention, the present invention will be appropriately and fully explained through the embodiments with reference to specific examples and the like. However, it should be understood that if the person has ordinary knowledge in the technical field, the above embodiments can be easily changed and / Or improvement. Therefore, as long as it does not deviate from the scope of the rights of the claims described in the scope of the patent application, the changed form or the improved form is interpreted as being included in the request. Items in the scope of rights.

Industrial availability

The present invention has wide industrial applicability in the technical field of non-aqueous electrolyte batteries such as lithium ion secondary batteries.

Claims (5)

    A viscosity-increasing stabilizer for a non-aqueous electrolyte battery electrode, which contains a neutralized salt of an α-olefin-maleic acid copolymer and a polyamine, which are copolymerized by α-olefins and maleic acid.         A binder composition for a non-aqueous electrolyte battery electrode, comprising the viscosity-increasing stabilizer and the particulate binder as claimed in claim 1.         A slurry composition for a non-aqueous electrolyte battery electrode, comprising the binder composition as claimed in claim 2, an active material, and water.         A non-aqueous electrolyte battery electrode is formed by combining a mixed layer containing a binder composition as claimed in claim 2 and an active material to a current collector.         A non-aqueous electrolyte battery having a non-aqueous electrolyte battery electrode as claimed in claim 4.