JP7110170B2 - Binder composition for nonaqueous electrolyte battery, binder aqueous solution for nonaqueous electrolyte battery using the same, slurry composition for nonaqueous electrolyte battery, electrode for nonaqueous electrolyte battery, and nonaqueous electrolyte battery - Google Patents

Description

The present invention relates to a binder composition for nonaqueous electrolyte batteries, an aqueous binder solution for nonaqueous electrolyte batteries using the same, a slurry composition for nonaqueous electrolyte batteries, an electrode for nonaqueous electrolyte batteries, and a nonaqueous electrolyte battery.

2. Description of the Related Art In recent years, mobile terminals such as mobile phones, notebook personal computers, and pad-type information terminal devices have spread remarkably. Lithium-ion secondary batteries are often used as secondary batteries used as power sources for these portable terminals. Since portable terminals are required to have more comfortable portability, they have rapidly become smaller, thinner, lighter, and have higher performance, and have come to be used in various places. This trend continues today, and batteries used in mobile terminals are also required to be smaller, thinner, lighter, and have higher performance.

A non-aqueous electrolyte battery such as a lithium ion secondary battery has a positive electrode and a negative electrode placed through a separator, and LiPF ₆ , LiBF ₄ LiTFSI (lithium (bistrifluoromethylsulfonylimide)), LiFSI (lithium (bisfluorosulfonylimide) )) is housed in a container together with an electrolytic solution obtained by dissolving a lithium salt in an organic liquid such as ethylene carbonate.

The negative electrode and the positive electrode are usually obtained by dissolving or dispersing a binder and a thickener in water or a solvent, and mixing an active material and, if necessary, a conductive agent (conductive agent). A slurry (hereinafter sometimes simply referred to as slurry) is applied to a current collector, and water or a solvent is dried to form a mixed layer that is bound and formed. More specifically, for example, the negative electrode is composed of a carbonaceous material capable of intercalating and deintercalating lithium ions, which is an active material, and, if necessary, a conductive agent such as acetylene black. They are bound together by a battery electrode binder. On the other hand, for the positive electrode, an active material such as LiCoO ₂ and, if necessary, a conductive aid similar to that used for the negative electrode are bound together to a current collector such as aluminum using a secondary battery electrode binder. It is.

In recent years, from the standpoints of reducing the load on the environment and simplifying production equipment, there has been an increasing interest in slurries using water from slurries using solvents.

The most industrially used binder for aqueous media is a system in which carboxymethyl cellulose sodium salt (CMC-Na) is added as a thickener to diene rubber such as styrene-butadiene rubber (SBR). (For example, Patent Document 1). However, diene-based rubbers such as styrene-butadiene rubber have low adhesiveness to metal collecting electrodes such as copper, and there is a problem that the amount used cannot be reduced in order to increase the adhesion between the collecting electrode and the electrode material. . In addition, there is also the problem that it is vulnerable to heat generated during charging and discharging, and the capacity retention rate is low. Further, since it is a two-liquid system, it has problems in manufacturing such as low storage stability and complicated slurry preparation process.

In order to solve the problems of SBR/CMC-Na addition systems, acrylic binders such as polyacrylic acid (eg, Patent Document 2) or polyamide/imide binders (eg, Patent Document 3) have been developed. .

Acrylic binders are excellent in that they exhibit high adhesiveness and have low swelling properties with respect to electrolytic solutions. On the other hand, there is a problem that the electrical resistance is high, the flexibility is poor, and the electrode is easily broken. Regarding flexibility, there are reports of introducing nitrile groups to improve flexibility, as in Patent Document 4, for example, but electrical resistance still tends to be high.

Polyamide/imide binders also exhibit high adhesiveness, and are particularly excellent in electrical and thermal stability and mechanical strength. As with acrylic binders, the problems include high electrical resistance, poor flexibility, and easy cracking of the electrodes. An example of compensating for flexibility by using a metal oxide having a large electrode expansion and contraction as a negative electrode active material has been reported (for example, Patent Document 5). However, the combination of a polyamide/imide binder and a metal oxide cannot sufficiently solve the problems of high resistance and poor flexibility, and furthermore, the polyamide/imide binder is expensive. There is also

Recently, there has been a growing demand for longer usage times and shorter charging times for mobile devices. There is an urgent need to improve

In a non-aqueous electrolyte battery, since the battery capacity is affected by the amount of active material, it is effective to reduce the amount of binder and thickener in order to increase the amount of active material in the limited space of the battery. The rate characteristics are also affected by the ease with which electrons move, so it is effective to reduce the amount of the binder and thickener, which are non-conductive and hinder the movement of electrons. However, when the amount of binder and thickener is reduced, the adhesion between the collecting electrode and the electrode material and the active material in the electrode is lowered, and the durability (battery life) for long-term use is only significantly lowered. Therefore, the electrode becomes fragile. Thus, until now, it has been difficult to improve the battery characteristics such as the battery capacity, especially to lower the resistance, while maintaining the adhesion between the collecting electrode and the electrode material and maintaining the toughness of the electrode.

The present invention has been made in view of the above problems, and the battery characteristics in a non-aqueous electrolyte battery without impairing the function as a binder, that is, the binding property between the active materials and with the collector electrode and the toughness as an electrode The purpose is to improve (high efficiency).

Japanese Unexamined Patent Application Publication No. 2014-13693 Japanese Patent Application Laid-Open No. 2002-260667 Japanese Patent Application Laid-Open No. 2001-68115 Japanese Patent Application Laid-Open No. 2003-282061 Japanese Patent Application Laid-Open No. 2015-65164

As a result of intensive studies aimed at solving the above problems, the present inventors have found that the above objects can be achieved by using a binder composition for non-aqueous electrolyte batteries having the following composition. The present invention was completed by stacking.

That is, the binder composition for non-aqueous electrolyte batteries according to one aspect of the present invention (hereinafter also simply referred to as the binder composition) comprises (A) polyvinyl alcohol, and (B) vinyl alcohol and ethylenically unsaturated carboxylic acid. and at least one selected from a copolymer and a neutralized salt thereof.

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

The binder composition for non-aqueous electrolyte batteries of the present embodiment (hereinafter also simply referred to as the binder composition) is characterized by comprising the following (A) and (B):
(A) polyvinyl alcohol,
(B) At least one selected from copolymers of vinyl alcohol and ethylenically unsaturated carboxylic acid and neutralized salts thereof.

According to the above configuration, it is possible to obtain a binder composition for a non-aqueous electrolyte battery having binding properties and toughness, and by using it, improve the battery characteristics (high efficiency) of the non-aqueous electrolyte battery. can do.

The content of polyvinyl alcohol as component (A) in the binder composition of the present embodiment is not particularly limited, but is preferably 50% by weight or less, and 40% by weight or less. is more preferable, and 30% by weight or less is even more preferable. The lower limit of the polyvinyl alcohol content is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, and even more preferably 1% by weight or more. If the content of component (A) exceeds 50% by weight, the electrical resistance may increase and high charge-discharge efficiency may not be obtained. If the content is less than 1% by weight, slurry stability may deteriorate. .

By including polyvinyl alcohol as the component (A), an effect of enhancing the cohesiveness of the binder due to the carboxyl group and the affinity with the collecting electrode and improving the adhesiveness can be expected. Further, by mixing different polymers, the molecular weight distribution appears to be broadened, and the crystallinity of the polymer is lowered, so that the effect of improving the flexibility can be expected. In addition, the effect of improving slurry stability can be expected by suppressing aggregation of a single polymer through intermolecular interaction with a different polymer.

In the present embodiment, the degree of saponification of polyvinyl alcohol is also not particularly limited, and is usually 50 mol% or more, more preferably 80 mol% or more, still more preferably 95 mol% or more. If the degree of saponification is low, it may be hydrolyzed by alkali metals contained in the binder composition, and the stability may not be determined, which is not preferable.

In the present embodiment, the ethylenically unsaturated carboxylic acid constituting the component (B) includes, for example, ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, methacrylic acid methyl esters, ethyl esters, and crotonic acid, Examples include ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid. Among these, acrylic acid, methacrylic acid, and maleic acid are particularly preferable from the viewpoint of availability, polymerization synthesis, and product stability. These ethylenically unsaturated carboxylic acid esters may be used alone or in combination of two or more.

The content ratio of vinyl alcohol and ethylenically unsaturated carboxylic acid in the copolymer of component (B) of the present embodiment is desirably in the range of 100/1 to 1/100 in terms of molar ratio. This is because the advantages of hydrophilicity, water solubility, and affinity for metals and ions as a water-soluble polymer can be obtained. If the amount of the ethylenically unsaturated carboxylic acid is too small, the adhesion and flexibility will be lowered, and if it is too large, the thermal and electrical stability will be lowered.

In at least one selected from (B) vinyl alcohol and ethylenically unsaturated carboxylic acid copolymers and neutralized salts thereof in the copolymer of the present embodiment, the copolymerization form is not particularly limited, and random copolymerization , alternating copolymerization, block copolymerization, graft copolymerization, and the like. In particular, block copolymerization or graft copolymerization in which vinyl alcohols are regularly arranged is preferred for obtaining high adhesiveness. Moreover, from the viewpoint of achieving both adhesiveness and flexibility, a graft copolymer is more preferable.

The method for producing the copolymer of the present embodiment is also not particularly limited, and any polymerization initiation method such as anionic polymerization, cationic polymerization, or radical polymerization may be used. , bulk polymerization, suspension polymerization, dispersion polymerization, or emulsion polymerization.

At least one selected from vinyl alcohol, an ethylenically unsaturated carboxylic acid copolymer, and a neutralized salt thereof, which is the component (B) of the present embodiment, has an ethylenically unsaturated carboxylic acid modification amount of 0.1. It is preferably about 60 mol %. Thereby, there is an advantage that toughness and low resistance can be imparted. A more preferable ethylenically unsaturated carboxylic acid modification amount is about 1 to 40 mol %. The amount of ethylenically unsaturated carboxylic acid modified in the present embodiment can be quantified by, for example, nuclear magnetic resonance spectroscopy (NMR).

From the viewpoint of heat resistance, the amount of ethylenically unsaturated carboxylic acid modification is preferably less than 20 mol %, more preferably less than 15 mol %. From the viewpoint of improving low resistance, it is also a preferred embodiment that the amount of modification with ethylenically unsaturated carboxylic acid is 11 mol % or more.

The number average molecular weight of the copolymer of the present embodiment is preferably from 5,000 to 250,000. If the number average molecular weight of the copolymer is less than 5,000, the mechanical strength of the binder may deteriorate. More preferably, the number average molecular weight is 10,000 or more, and even more preferably 15,000 or more. On the other hand, if the number-average molecular weight of the copolymer exceeds 250,000, the viscosity stability of the slurry composition for non-aqueous electrolyte batteries may be lowered, or the slurry may aggregate, resulting in insufficient handleability. There is a risk. More preferably, the number average molecular weight is 200,000 or less, and even more preferably 150,000 or less. The number average molecular weight of the copolymer in the present invention means a value measured by a gel permeation chromatography (GPC) method using polyethylene oxide and polyethylene glycol as standard substances and an aqueous column as a column.

In the present embodiment, the neutralized salt of the copolymer means that the active hydrogen of the carbonyl acid generated from the ethylenically unsaturated carboxylic acid reacts with a basic substance to form a salt and become a neutralized product. It is preferable to be In the (B) vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer and/or neutralized salt thereof used in the present embodiment, a monovalent metal is used as the basic substance from the viewpoint of binding properties as a binder. It is preferred to use a basic substance containing and/or ammonia.

Basic substances containing a monovalent metal that can be used in the present embodiment include, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metals such as sodium carbonate and potassium carbonate; carbonates; alkali metal acetates such as sodium acetate and potassium acetate; alkali metal phosphates such as trisodium phosphate. Among these, ammonia, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferred. In particular, ammonia and lithium hydroxide are preferably used as binders for lithium ion secondary batteries. A basic substance containing a monovalent metal and/or ammonia may be used alone or in combination of two or more. In addition, a basic substance containing an alkali metal hydroxide such as sodium hydroxide may be used in combination to prepare the neutralized product, as long as it does not adversely affect the battery performance.

The degree of neutralization is not particularly limited, but when it is used as a binder, it is usually 0.00 to the carboxylic acid generated from the ethylenically unsaturated carboxylic acid in consideration of the reactivity with the electrolytic solution. It is preferably in the range of 1 to 1 equivalent, more preferably in the range of 0.3 to 1 equivalent, and preferably neutralized. With such a degree of neutralization, there is an advantage that the acidity is low and the decomposition of the electrolytic solution is suppressed.

In the present embodiment, the method for determining the degree of neutralization can be titration with a base, infrared spectrum, NMR spectrum, or the like. In order to simply and accurately measure the neutralization point, titration with a base is used. preferably. A specific titration method is not particularly limited. It can be carried out by carrying out neutralization. The indicator for the neutralization point is not particularly limited, but an indicator such as phenolphthalein that indicates pH with a base can be used.

In the present embodiment, the amount of the basic substance containing a monovalent metal and/or ammonia used is not particularly limited and is appropriately selected depending on the purpose of use. It is preferable that the amount is 0.1 to 1 equivalent with respect to The amount of the basic substance containing a monovalent metal used is preferably 0.3 to 1.0 equivalents, more preferably 0.4 to 1.0 equivalents, relative to the maleic acid units in the maleic acid copolymer. When the amount is equivalent, a water-soluble copolymer salt with little residual alkali can be obtained.

In the present embodiment, (B) the reaction of vinyl alcohol with an ethylenically unsaturated carboxylic acid copolymer and/or a neutralized salt thereof can be carried out according to a conventional method, but is carried out in the presence of water to obtain a neutralized product. A method of obtaining an aqueous solution is simple and preferable.

The content of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer and/or neutralized salt thereof, which is the component (B), in the binder composition of the present embodiment is not particularly limited. It is preferably 99.9% by weight or less, more preferably 99.5% by weight or less, and even more preferably 99% by weight or less. The lower limit of the content is preferably 50% by weight or more, more preferably 60% by weight or more, still more preferably 70% by weight or more, and 80% by weight or more. Especially preferred. If the content of component (B) exceeds 99.9% by weight, the slurry stability may deteriorate. There is

In the present embodiment, the composition ratio of the component (A) and the component (B) is preferably about 0.1:99.9 to 50:50 in solid content weight ratio. More preferably, it is about 1:99 to 40:60. From the viewpoint of obtaining low resistance, the composition ratio of the component (A) and the component (B) is preferably 1:99 to 30:70, and is about 1:99 to 20:80. is more preferred.

The binder composition of the present embodiment is generally used as an aqueous binder solution for non-aqueous electrolyte batteries, which consists of the binder composition described above and water.

The binder composition for non-aqueous electrolyte batteries of the present embodiment is a slurry composition for non-aqueous electrolyte batteries (hereinafter, simply slurry composition Also called) is preferably used as. That is, the slurry composition of this embodiment contains the binder composition of this embodiment described above, an active material, and water.

Further, in the present embodiment, the electrode for a non-aqueous electrolyte battery is characterized in that a mixed layer containing at least the binder composition of the present embodiment and an active material is bound to a current collector. This electrode can be formed by applying the above slurry composition to a current collector and then removing the solvent by a method such as drying. If necessary, a thickener, a conductive aid, etc. can be added to the mixed layer.

In the slurry composition for a nonaqueous electrolyte battery, the amount of the binder composition used is usually preferably 0.1 to 15% by weight, more preferably 0.1 to 15% by weight, based on the weight of the active material being 100%. 5 to 10% by weight, more preferably 1 to 8% by weight. If the amount of the binder composition is too small, the viscosity of the slurry will be too low and the thickness of the mixed layer may become thin. If the amount of the binder composition is too large, the discharge capacity may decrease.

On the other hand, the amount of water in the slurry composition is usually preferably 30 to 150% by weight, more preferably 70 to 120% by weight, when the weight of the active material is 100%.

As the solvent in the slurry composition of the present embodiment, in addition to water, for example, alcohols such as methanol, ethanol, propanol, 2-propanol, tetrahydrofuran, cyclic ethers such as 1,4-dioxane, N,N- Amides such as dimethylformamide and N,N-dimethylacetamide, cyclic amides such as N-methylpyrrolidone and N-ethylpyrrolidone, and sulfoxides such as dimethylsulfoxide can also be used. Among these, the use of water is preferable from the viewpoint of safety.

In addition to water, the following organic solvent may be used as the solvent for the slurry composition of the present embodiment, preferably within a range of 20% by weight or less of the entire solvent. Such an organic solvent preferably has a boiling point of 100° C. or higher and 300° C. or lower at normal pressure. Examples include hydrocarbons such as n-dodecane; alcohols such as 2-ethyl-1-hexanol and 1-nonanol. esters such as γ-butyrolactone and methyl lactate; amides such as N-methylpyrrolidone, N,N-dimethylacetamide and dimethylformamide; and organic dispersion media such as sulfoxides and sulfones such as dimethylsulfoxide and sulfolane.

When the slurry composition of the present embodiment is used for a negative electrode, the negative electrode active material added to the slurry composition includes, for example, amorphous carbon, graphite, natural graphite, mesocarbon microbeads (MCMB), pitch-based carbon fiber, and the like. carbonaceous materials; conductive polymers such as polyacene; composite metal oxides represented by SiOx, SnOx, _LiTiOx , other metal oxides, lithium metals, lithium _- based metals such as lithium alloys; and the like are exemplified.

When the slurry composition of the present embodiment is used for a positive electrode, the positive electrode active material added to the slurry composition includes, for example, lithium iron phosphate (LiFePO ₄ ), lithium manganese phosphate (LiMnPO ₄ ), phosphoric acid Lithium cobalt (LiCoPO ₄ ), iron pyrophosphate (Li ₂ FeP ₂ O ₇ ), lithium cobaltate composite oxide (LiCoO ₂ ), spinel type lithium manganate composite oxide (LiMn ₂ O ₄ ), lithium manganate composite oxide (LiMnO ₂ ), lithium nickelate composite oxide (LiNiO ₂ ), lithium niobate composite oxide (LiNbO ₂ ), lithium ferrate composite oxide (LiFeO ₂ ), lithium magnesium oxide composite oxide (LiMgO ₂ ), Lithium calcate composite oxide (LiCaO ₂ ), Lithium cuprate composite oxide (LiCuO ₂ ), Lithium zincate composite oxide (LiZnO ₂ ), Lithium molybdate composite oxide (LiMoO ₂ ), Lithium tantalate composite oxide (LiTaO ₂ ), lithium tungstate composite oxide (LiWO ₂ ), lithium-nickel-cobalt-aluminum composite oxide (LiNi _0.8 Co _0.15 Al _0.05 O ₂ ), lithium-nickel-cobalt-manganese Composite oxide (LiNi _0.33 Co _0.33 Mn _0.33 O ₂ ), Li-excess nickel-cobalt-manganese composite oxide (LixNiACoBMnCO ₂ solid solution), manganese nickel oxide (LiNi _0.5 Mn _1.5 O ₄ ), manganese oxide (MnO ₂ ), vanadium-based oxides, sulfur-based oxides, silicate-based oxides, and the like.

In this embodiment, a thickening agent can be added to the slurry composition as needed. The thickening agent that can be added is not particularly limited, and various alcohols, unsaturated carboxylic acids and modified products thereof, α-olefin-maleic acids and modified products thereof, celluloses, and polysaccharides such as starch can be used. can be used.

The amount of the thickening agent that is optionally blended in the slurry composition is preferably about 0.1 to 4% by weight, more preferably 0.3 to 4% by weight, when the weight of the active material is 100. 3% by weight, more preferably 0.5 to 2% by weight. If the amount of the thickening agent is too small, the viscosity of the secondary battery negative electrode slurry is too low and the thickness of the mixed layer may become thin. Conversely, if the amount of the thickening agent is too large, the discharge capacity may decrease. .

Examples of conductive aids that are optionally blended into the slurry composition include metal powders, conductive polymers, and acetylene black. The amount of the conductive aid used is preferably 0.1 to 10% by weight, more preferably 0.8 to 7% by weight, when the weight of the active material is 100%.

As described above, in the present embodiment, the electrode for a non-aqueous electrolyte battery is characterized by binding a mixed layer containing at least the binder composition of the present embodiment and an active material to a current collector. The current collector used in the negative electrode of the non-aqueous electrolyte battery of the present embodiment is not particularly limited as long as it is made of a conductive material. , platinum and other metal materials can be used. One of these may be used alone, or two or more of them may be used in combination at any ratio.

In particular, when copper is used as the current collector for the negative electrode, the effect of the slurry for the negative electrode of the non-aqueous electrolyte battery of the present invention appears most effectively. This is because the binder composition of the present embodiment has a high affinity with the copper foil, and a negative electrode having high adhesiveness can be produced. Although the shape of the current collector is not particularly limited, it is usually preferably in the form of a sheet with a thickness of about 0.001 to 0.5 mm.

Furthermore, when aluminum is used as the current collector for the positive electrode, the effect of the slurry for the negative electrode of the non-aqueous electrolyte battery of the present invention appears most effectively. This is because the binder composition of the present embodiment has a high affinity with the aluminum foil, and a negative electrode having high adhesiveness can be produced. Although the shape of the current collector is not particularly limited, it is usually preferably in the form of a sheet with a thickness of about 0.001 to 0.5 mm.

The method of applying the slurry to the current collector is not particularly limited. For example, doctor blade method, dip method, reverse roll method, direct roll method, gravure method, extrusion method, immersion method, brush coating method and the like can be used. The amount to be applied is not particularly limited, but the thickness of the mixed layer containing the active material, conductive aid, binder and thickener formed after removing the solvent or dispersion medium by a method such as drying is preferably 0.005 to 0.005. An amount of 5 mm, more preferably 0.01 to 2 mm is common.

The method for drying the solvent such as water contained in the slurry composition is not particularly limited, and includes, for example, hot air, hot air, and low humidity air drying; vacuum drying; infrared rays, far infrared rays, irradiation drying such as electron beams, and the like. . The drying conditions should be adjusted so that the solvent can be removed as quickly as possible within a speed range in which the active material layer does not crack due to stress concentration or the active material layer does not separate from the current collector. Furthermore, it is effective to press the dried current collector in order to increase the density of the active material of the electrode. Examples of the pressing method include methods such as die pressing and roll pressing.

Furthermore, the present invention also includes a non-aqueous electrolyte battery having the above electrodes. A non-aqueous electrolyte battery typically includes a negative electrode, a positive electrode, and an electrolyte.

When the binder composition of the present embodiment is used for the positive electrode, negative electrodes that are commonly used in non-aqueous electrolyte batteries such as lithium ion secondary batteries are used without particular limitations. For example, graphite, hard carbon, Si-based oxides, and the like are used as the negative electrode active material. Further, the negative electrode active material is a mixture of the above-described conductive aid and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, etc. The negative electrode slurry prepared by mixing with a solvent or the like at a temperature of 10° C. or below can be applied to, for example, a negative electrode current collector such as a copper foil, and the solvent can be dried to form a negative electrode.

When the binder composition of the present embodiment is used for the negative electrode, the positive electrode normally used for non-aqueous electrolyte batteries such as lithium ion secondary batteries is used without particular limitation. For example, positive electrode active materials include TiS ₂ , TiS ₃ , amorphous MoS ₃ , Cu ₂ V ₂ O ₃ , amorphous V ₂ O—P ₂ O ₅ , MoO ₃ , V ₂ O ₅ and V ₆ O. transition metal oxides such as ₁₃ and lithium-containing composite metal oxides such as LiCoO ₂ , LiNiO ₂ , LiMnO ₂ and LiMn ₂ O ₄ are used. Further, the positive electrode active material is a mixture of the above-described conductive aid and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, etc. A positive electrode slurry prepared by mixing with a solvent or the like at a temperature of 10° C. or below can be applied to a positive electrode current collector such as aluminum, and the solvent can be dried to form a positive electrode.

An electrode containing the binder composition of the present embodiment can also be used for both the positive electrode and the negative electrode.

Further, an electrolytic solution in which an electrolyte is dissolved in a solvent can be used for the non-aqueous electrolyte battery of the present embodiment. The electrolyte may be liquid or gel as long as it is used in non-aqueous electrolyte batteries such as lithium ion secondary batteries, and exhibits battery functions depending on the type of negative electrode active material and positive electrode active material. You can choose what to do. As a specific electrolyte, for example, any conventionally known lithium salt can be used, including LiClO ₄ , LiBF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , LiB ₁₀ Cl ₁₀ , _LiAlCl4 , LiCl, LiBr, LiB _{( C2H5} ) _{4 , CF3SO3Li , CH3SO3Li , LiCF3SO3 , LiC4F9SO3 ,} Li _{( CF3SO2} ) _2N , lithium lower aliphatic carboxylate, and the like.

A solvent (electrolyte solvent) for dissolving such an electrolyte is not particularly limited. Specific examples include carbonates such as propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate and diethyl carbonate; lactones such as γ-butyl lactone; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether and 2-ethoxyethane. , tetrahydrofuran, ethers such as 2-methyltetrahydrofuran; sulfoxides such as dimethylsulfoxide; oxolane such as 1,3-dioxolane and 4-methyl-1,3-dioxolane; nitrogen-containing compounds such as acetonitrile and nitromethane; formic acid organic acid esters such as methyl, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate; inorganic acid esters such as triethyl phosphate, dimethyl carbonate, and diethyl carbonate; diglymes; triglymes; sulfolanes; oxazolidinones such as 3-methyl-2-oxazolidinone; sultones such as 1,3-propanesultone, 1,4-butanesultone and naphthsultone; these can be used alone or in combination of two or more. When a gel electrolyte 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, but the following manufacturing method is exemplified, for example. That is, the negative electrode and the positive electrode are superimposed via a separator such as a polypropylene porous film, rolled or folded according to the shape of the battery, placed in a battery container, an electrolytic solution is injected, and the opening is sealed. The shape of the battery may be any known coin type, button type, sheet type, cylindrical type, square type, flat type, or the like.

The non-aqueous electrolyte battery of the present embodiment is a battery that achieves both improved adhesion and improved battery characteristics, and is useful in various applications. For example, it is very useful as a battery for use in portable terminals that are required to be smaller, thinner, lighter, and have higher performance.

As described above, this specification discloses technologies of various aspects, and the main technologies thereof are summarized below.

A binder composition for a non-aqueous electrolyte battery according to one aspect of the present invention is selected from (A) polyvinyl alcohol and (B) a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid and a neutralized salt thereof. characterized by including at least one

It is believed that such a configuration can improve the battery characteristics without impairing the adhesion between the active materials and the collector electrode and the toughness as an electrode.

In the binder composition, at least one selected from (B) a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid and a neutralized salt thereof is copolymerized in the form of block copolymerization. is preferred. It is believed that higher adhesion is thereby obtained.

Further, in the binder composition, at least one selected from (B) a copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid and a neutralized salt thereof is copolymerized in the form of graft copolymerization. is preferred. Therefore, it is considered that both adhesiveness and flexibility can be achieved.

In the binder composition, at least one selected from (B) a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralized salt thereof has an ethylenically unsaturated carboxylic acid modification amount of 0. .1 to 60 mol %. It is thought that toughness and low resistance can be imparted thereby.

Also, the content of the component (B) in the binder composition is preferably 50.0 to 99.9% by weight. As a result, it is considered that slurry stability and higher charge/discharge efficiency can be obtained.

An aqueous binder solution for non-aqueous electrolyte batteries according to still another aspect of the present invention is characterized by containing the binder composition and water.

A slurry composition for a nonaqueous electrolyte battery according to still another aspect of the present invention is characterized by containing the above binder composition, an active material, and water.

Further, according to still another aspect of the present invention, there is provided an electrode for a non-aqueous electrolyte battery, comprising a current collector and a mixed layer containing the binder composition and the active material.

A non-aqueous electrolyte battery according to still another aspect of the present invention is characterized by having the electrode for a non-aqueous electrolyte battery.

Examples of the present invention will be described below, but the present invention is not limited to these.

(Example 1)
<Synthesis of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>
100 g of commercially available polyvinyl alcohol (28-98s, manufactured by Kuraray Co., Ltd.) was irradiated with an electron beam (30 kGy). Next, 33.4 g of acrylic acid and 466.6 g of methanol were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a particle addition port, and the inside of the system was replaced with nitrogen for 30 minutes while bubbling with nitrogen. . 100 g of electron beam-irradiated polyvinyl alcohol was added thereto, and the mixture was stirred to disperse the particles in the solution, and the mixture was heated under reflux for 300 minutes for graft polymerization. After that, the particles were collected by filtration and vacuum-dried at 40° C. overnight to obtain the target copolymer. The ethylenically unsaturated carboxylic acid modification amount of the obtained copolymer was 6.8 mol %.

<Preparation of neutralized salt of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>
To 100 g of the 10% by weight aqueous solution of vinyl alcohol and acrylic acid copolymer obtained above, 0.5 equivalent of lithium hydroxide is added to the carboxylic acid unit in the polymer, and the mixture is heated and stirred at 80° C. for 2 hours, and then Cooled to room temperature.

<Adjustment of binder aqueous solution>
Commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., 28-98s, degree of saponification: 98) (A-1) was added as a solid content so that the weight ratio was (A-1):(B-1)=10:90 to prepare an aqueous binder solution.

<Measurement of melting point of neutralized salt of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>
Differential scanning calorimetry was performed using a thermal analyzer (manufactured by Yamato Scientific Co., Ltd.) using a solid obtained by drying 1 g of the aqueous binder solution with a hot air dryer at 105° C. for 1 hour. The measurement was carried out at a temperature range of 50°C to 1000°C and a heating rate of 10°C/min. The results are shown in Table 1 below.

<Preparation of slurry>
Preparation of electrode slurry is performed by adding 96 parts by weight of natural graphite (DMGS, manufactured by BYD) as a negative electrode active material, 3 parts by weight of a 10% by weight aqueous solution of the binder composition as a solid content, and a conductive aid (conductivity imparting As an agent), 1 part by weight of Super-P (manufactured by Timcal Co., Ltd.) as a solid content was put into a special container and kneaded using a planetary stirrer (ARE-250, manufactured by Thinky) to prepare a slurry for electrode coating. . The composition ratio of the active material and the binder in the slurry was graphite powder:conduction aid:binder composition=96:1:3 (weight ratio) as solid content.

<Slurry stability>
In order to confirm the stability of the obtained slurry, the state of particle sedimentation immediately after slurry preparation (within 30 minutes) was visually confirmed. Slurries that did not precipitate were marked with ◯, and slurries that precipitated were marked with ×. The results are shown in Table 1 below.

<Preparation of negative electrode for battery>
The obtained slurry is coated on a current collector copper foil (CST8G, manufactured by Fukuda Metal Foil & Powder Co., Ltd.) using a bar coater (T101, manufactured by Matsuo Sangyo Co., Ltd.), and dried at 80 ° C. for 30 minutes with a hot air dryer. After primary drying, rolling treatment was performed using a roll press (manufactured by Hosen). Then, after punching out a battery electrode (φ14 mm), a coin battery electrode was produced by secondary drying under reduced pressure conditions at 140° C. for 3 hours.

<Preparation of electrode for peel strength and toughness test>
The obtained slurry is coated on a current collector copper foil (CST8G, manufactured by Fukuda Metal Foil & Powder Co., Ltd.) using a bar coater (T101, manufactured by Matsuo Sangyo Co., Ltd.), and dried at 80 ° C. for 30 minutes with a hot air dryer. After primary drying at , a test was performed using an electrode (thickness: about 40 μm) that had been subjected to rolling treatment using a roll press (manufactured by Hosen).

<Electrode toughness test>
The toughness of the electrode was evaluated using the toughness test electrode with a width of 10 mm, and it was visually confirmed whether cracks occurred when the electrode was bent. An electrode with no cracks was marked with ◯, and an electrode with cracks was marked with x. The results are shown in Table 1 below.

<Measurement of peel strength of electrode>
The strength was measured when the electrode for peel strength test was peeled off from the copper foil as the collector electrode. The peel strength was measured as 180° peel strength using a 50N load cell (manufactured by Imada Co., Ltd.). The slurry-coated surface of the battery-coated electrode obtained above and the stainless steel plate are laminated using a double-sided tape (Nichiban double-sided tape), and the 180° peel strength (peeling width 10 mm, peeling speed 100 mm / min) is measured. did. The above results are shown in Table 1 below.

<Production of battery>
The battery negative electrode obtained above was transferred to a glove box (manufactured by Miwa Seisakusho) under an argon gas atmosphere. A metallic lithium foil (thickness: 0.2 mm, φ: 16 mm) was used for the positive electrode. In addition, a polypropylene separator (Celgard #2400, manufactured by Polypore) was used as the separator, and the electrolyte was lithium hexafluorophosphate (LiPF ₆ ) in ethylene carbonate (EC) and ethyl methyl carbonate (EMC) and vinylene carbonate ( A mixed solvent system (1M-LiPF ₆ , EC/EMC = 3/7 vol%, VC 2% by weight) to which VC) was added was injected to prepare a coin battery (2032 type).

<Charge-discharge characteristic test>
The produced coin battery was subjected to a charge/discharge test using a commercially available charge/discharge tester (TOSCAT3100, manufactured by Toyo System Co., Ltd.). The coin battery was placed in a constant temperature bath at 25° C., and was charged at a constant current of 0.1 C (approximately 0.5 mA/cm ² ) with respect to the amount of active material until the lithium potential reached 0 V. A constant voltage charge of 0 V was performed to a current of 0.02 mA. The capacity at this time was defined as the charge capacity (mAh/g). Then, the battery was discharged to 1.5 V at a constant current of 0.1 C (about 0.5 mA/cm ² ) with respect to the lithium potential, and the capacity at this time was defined as the discharge capacity (mAh/g). The difference between initial discharge capacity and charge capacity was defined as irreversible capacity, and the percentage of discharge capacity/charge capacity was defined as charge/discharge efficiency. The above results are shown in Table 1 below.

(Example 2)
A vinyl alcohol/ethylenically unsaturated carboxylic acid copolymer was synthesized in the same manner as in Example 1. Further, 1.0 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-2) of the copolymer. Thereafter, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-2)=10:90, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 3)
A target copolymer was synthesized in the same manner as in Example 1, except that 100 g of acrylic acid and 400 g of methanol were added. The ethylenically unsaturated carboxylic acid modification amount of the obtained copolymer was 26.2 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-3) of the copolymer. After that, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-3):(B-3)=7:93, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 4)
100 g of commercially available polyvinyl alcohol (22-88s, manufactured by Kuraray Co., Ltd.) was irradiated with an electron beam (30 kGy). Next, 33.5 g of acrylic acid and 466.5 g of methanol were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a particle addition port, and the inside of the system was replaced with nitrogen for 30 minutes while bubbling with nitrogen. . 100 g of electron beam-irradiated polyvinyl alcohol was added thereto, and the mixture was stirred to disperse the particles in the solution, and the mixture was heated under reflux for 300 minutes for graft polymerization. After that, the particles were collected by filtration and vacuum-dried at 40° C. overnight to obtain the target copolymer. The ethylenically unsaturated carboxylic acid modification amount of the obtained copolymer was 7.1 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-4) of the copolymer. After that, commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., 22-88s, degree of saponification: 88) (A-2) was used as a solid content, and the weight ratio was (A-2): (B-4) = 10:90. was added so that the binder aqueous solution was adjusted.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 5)
100 g of commercially available polyvinyl alcohol (Elvanol 71-30 manufactured by Kuraray Co., Ltd.) was irradiated with an electron beam (30 kGy). Next, 25 g of methacrylic acid and 475 g of methanol were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a particle addition port, and the system was replaced with nitrogen for 30 minutes while bubbling with nitrogen. 100 g of electron beam-irradiated polyvinyl alcohol was added thereto, and the mixture was stirred to disperse the particles in the solution, and the mixture was heated under reflux for 300 minutes for graft polymerization. After that, the particles were collected by filtration and vacuum-dried at 40° C. overnight to obtain the target copolymer. The ethylenically unsaturated carboxylic acid modification amount of the obtained copolymer was 7.0 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-5) of the copolymer. Then, commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Elvanol 71-30, degree of saponification: 99) (A-3) as a solid content, weight ratio (A-3): (B-5) = 12:88. was added so as to adjust the binder aqueous solution.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 6)
A target copolymer was synthesized in the same manner as in Example 5 except that 100 g of methacrylic acid and 400 g of methanol were added. The ethylenically unsaturated carboxylic acid modification amount of the resulting copolymer was 34.0 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-6) of the copolymer. Thereafter, the same commercial polyvinyl alcohol (A-3) as in Example 5 was added as a solid content so that the weight ratio was (A-3):(B-6)=5:95, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 7)
370 g of water and 100 g of commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., M115) were charged into a reactor equipped with a stirrer, a reflux condenser, a nitrogen introduction tube, and an initiator addition port, and heated at 95° C. with stirring. After dissolving the polyvinyl alcohol, it was cooled to room temperature. 0.5 normality (N) of sulfuric acid was added to the aqueous solution to adjust the pH to 3.0. After adding 9.9 g of acrylic acid with stirring, the aqueous solution was heated to 70° C. while nitrogen was bubbled through it, and nitrogen was bubbled for 30 minutes at 70° C. to replace with nitrogen. After purging with nitrogen, 80.7 g of an aqueous potassium persulfate solution (concentration: 2.5% by weight) was added dropwise to the aqueous solution over 1.5 hours. After the total amount was added, the temperature was raised to 75° C. and the mixture was further stirred for 1 hour, and then cooled to room temperature. The resulting aqueous solution was poured onto a PET film and dried with hot air at 80° C. for 30 minutes to prepare a film. The film was frozen with liquid nitrogen, pulverized using a centrifugal pulverizer, and vacuum-dried at 40° C. overnight to obtain the target copolymer. The ethylenically unsaturated carboxylic acid modification amount of the resulting copolymer was 6.0 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-7) of the copolymer. Thereafter, the same commercial polyvinyl alcohol (A-1) as in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-7)=10:90, and the aqueous binder solution was prepared. made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 8)
A vinyl alcohol/ethylenically unsaturated carboxylic acid copolymer was synthesized in the same manner as in Example 7. Further, 1.0 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-8) of the copolymer. Thereafter, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-8)=10:90, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 9) Vinyl alcohol and an ethylenically unsaturated carboxylic acid copolymer were prepared in the same manner as in Example 7, except that 20 g of acrylic acid and 150 g of an aqueous potassium persulfate solution (concentration: 2.5% by weight) were added. Synthesized. The ethylenically unsaturated carboxylic acid modification amount of the resulting copolymer was 12.0 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-9) of the copolymer. After that, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-9)=10:90, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 10) A copolymer of vinyl alcohol and ethylenically unsaturated carboxylic acid was synthesized in the same manner as in Example 9. Further, 0.3 equivalents of sodium hydroxide and 0.2 equivalents of lithium hydroxide are added to the carboxylic acid units in the polymer to obtain a neutralized salt of the copolymer ( B-10) was prepared. After that, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-10)=10:90, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 11)

640 g of vinyl acetate, 240.4 g of methanol, and 0.88 g of acrylic acid were charged into a reactor equipped with a stirrer, a reflux condenser, an argon introduction tube, and an initiator addition port, and nitrogen was bubbled through the system for 30 minutes. replaced. Separately, a methanol solution of acrylic acid (concentration 20% by weight) was prepared as a comonomer sequential addition solution (hereinafter referred to as a delay solution), and argon was bubbled through it for 30 minutes. Heating of the reactor was started, and when the internal temperature reached 60° C., 0.15 g of 2,2′-azobisisobutyronitrile was added to initiate polymerization. During the progress of the polymerization reaction, the prepared delay solution was dropped into the system so that the monomer composition (molar ratio of vinyl acetate and acrylic acid) in the polymerization solution was kept constant. After polymerizing at 60° C. for 210 minutes, the polymerization was stopped by cooling. Subsequently, unreacted monomers were removed at 30° C. under reduced pressure while occasionally adding methanol to obtain a methanol solution of acrylic acid-modified polyvinyl acetate. Next, 20.4 g of a sodium hydroxide methanol solution (concentration of 18.0% by weight) was added to 400 g of a methanol solution of polyvinyl acetate prepared by adding methanol to the methanol solution of polyvinyl acetate to a concentration of 25% by weight. , and 79.6 g of methanol were added to perform saponification at 40°C. Several minutes after the sodium hydroxide methanol solution was added, a gelled product was formed, which was pulverized with a pulverizer and allowed to stand at 40° C. for 60 minutes to promote saponification. The pulverized gel thus obtained was repeatedly washed with methanol and then vacuum-dried at 40° C. overnight to synthesize the target copolymer. The ethylenically unsaturated carboxylic acid modification amount of the obtained copolymer was 5.0 mol %. Further, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-11) of the copolymer. After that, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-11)=10:90, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 12)

Using the same neutralized salt (B-11) as in Example 11, the same commercially available polyvinyl alcohol (A-1) as in Example 1 was used as the solid content, and the weight ratio was (A-1):(B-11). )=40:60 to prepare an aqueous binder solution.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Example 13)

A vinyl alcohol/ethylenically unsaturated carboxylic acid copolymer was synthesized in the same manner as in Example 11. Further, 1.0 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare a neutralized salt (B-13) of the copolymer. Thereafter, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added as a solid content so that the weight ratio was (A-1):(B-13)=10:90, and the aqueous binder solution was made adjustments.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Comparative example 1)

A 10% by weight aqueous solution of commercially available polyvinyl alcohol (28-98s, saponification degree: 98, manufactured by Kuraray Co., Ltd.) was prepared and used as a binder composition. A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Comparative example 2)

A 10% by weight aqueous solution of commercially available polyvinyl alcohol (22-88s, saponification degree: 88, manufactured by Kuraray Co., Ltd.) was prepared and used as a binder composition. A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Comparative Example 3)
Using the same neutralized salt as in Example 1, a 10% by weight aqueous solution was prepared and used as a binder composition. A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Comparative Example 4)
Using the same neutralized salt as in Example 7, a 10% by weight aqueous solution was prepared and used as a binder composition. A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Comparative Example 5)
Using the same neutralized salt as in Example 11, a 10% by weight aqueous solution was prepared and used as a binder composition. A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Comparative Example 6)
A 10% by weight aqueous solution of polyacrylic acid (manufactured by Aldrich, molecular weight 250,000) was prepared and used as a binder composition. A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1, and the stability of the slurry was confirmed. Furthermore, a coated negative electrode for a battery was produced by the same method as in Example 1, a coin battery was obtained, and a charge-discharge characteristic test was performed. Similarly, a coated electrode for toughness test and peel strength was prepared by the same method as in Example 1, and using it, the toughness test and peel strength measurement were performed. The results are shown in Table 1 below.

(Discussion)
In Examples 1 to 13 containing the components (A) and (B) of the present invention, it was shown that a high charge-discharge efficiency of 92% or more was achieved due to the effect of the neutralizing salt. It is hypothesized that the polymer salt coated the powdered active material to form an ionically conductive layer that facilitated the movement of Li ions within the cell. In addition, the coexistence of two or more components (A) component and (B) component was found to improve slurry stability, toughness, and adhesiveness. On the other hand, Comparative Examples 1 to 2 and 6, which do not contain a neutralizing salt, resulted in low charge/discharge efficiency (less than 92%), slurry stability, toughness, and adhesiveness.

In addition, although Comparative Examples 3 to 5 showed high charge-discharge efficiency as in the Examples, on the other hand, it was difficult to form a uniform electrode due to the low slurry stability. sex wasn't good enough.

From the above, it was clarified that the use of the binder composition of the present invention can improve the battery characteristics of non-aqueous electrolyte batteries without impairing the binding properties of the electrode binder and the toughness of the electrode.

This application is based on Japanese Patent Application No. 2017-50807 filed on March 16, 2017, the contents of which are incorporated herein.

In order to express the present invention, the present invention has been adequately and fully described through the embodiments with reference to specific examples and the like in the foregoing, but those skilled in the art can easily modify and/or improve the above-described embodiments. It should be recognized that it is something that can be done. Therefore, to the extent that modifications or improvements made by those skilled in the art do not deviate from the scope of the claims set forth in the claims, such modifications or modifications do not fall within the scope of the claims. is interpreted to be subsumed by

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

Claims (8)

(A) polyvinyl alcohol, and
(B) at least one selected from copolymers of vinyl alcohol and ethylenically unsaturated carboxylic acid and neutralized salts thereof,
The composition ratio of the component (A) and the component (B) is 1:99 to 50:50 in solid content weight ratio,
The content ratio of vinyl alcohol and ethylenically unsaturated carboxylic acid in the copolymer of component (B) is 100/1 to 1/100 in terms of molar ratio,
The copolymer of component (B) has a number average molecular weight of 5,000 to 250,000,
A binder composition for a non-aqueous electrolyte battery, characterized in that the amount of ethylenically unsaturated carboxylic acid modification in the component (B) is 0.1 to 60 mol% ,
A binder composition for a non-aqueous electrolyte battery, wherein the content of the component (A) in the binder composition is 1% by weight or more and 50% by weight or less . At least one selected from (B) a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralized salt thereof is copolymerized in the form of a block copolymer, according to claim 1 A binder composition for water electrolyte batteries. At least one selected from (B) a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralized salt thereof is copolymerized in the form of a graft copolymerization. A binder composition for water electrolyte batteries. 4. The binder composition for non-aqueous electrolyte batteries according to claim 1, wherein the content of said component (B) in said binder composition is 50.0 to 99.0 % by weight. An aqueous binder solution for non-aqueous electrolyte batteries, containing the binder composition according to any one of claims 1 to 4 and water. A slurry composition for a non-aqueous electrolyte battery, comprising the binder composition according to any one of claims 1 to 4, an active material and water. An electrode for a non-aqueous electrolyte battery, comprising a current collector and a mixed layer containing the binder composition according to any one of claims 1 to 4 and an active material. A nonaqueous electrolyte battery comprising the electrode for a nonaqueous electrolyte battery according to claim 7 .