TW201840045A - Binder composition for non-aqueous electrolyte batteries, and binder aqueous solution for non-aqueous electrolyte batteries, slurry composition and electrod for non-aqueous electrolyte batteries, and non-aqueous electrolyte battery - Google Patents

Abstract

The present invention relates to: a binder composition for non-aqueous electrolyte batteries, characterized by containing (A) polyvinyl alcohol and (B) at least one component selected from a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and neutralized salts thereof; and a binder aqueous solution for non-aqueous electrolyte batteries, a slurry composition for non-aqueous electrolyte batteries, an electrode for non-aqueous electrolyte batteries, a non-aqueous electrolyte battery and the like, in each of which the binder composition is used.

Description

   Adhesive composition for non-aqueous electrolyte battery, and aqueous binder solution for non-aqueous electrolyte battery, slurry composition for non-aqueous electrolyte battery, electrode for non-aqueous electrolyte battery, and non-aqueous electrolyte battery   

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

In recent years, the popularity of mobile terminals such as mobile phones, notebook computers, and tablet-type information terminal devices has been remarkable. Among the secondary batteries used in power sources of these mobile terminals, lithium ion secondary batteries are mostly used. Mobile terminals require more comfortable portability. Therefore, miniaturization, thinness, weight reduction, and high performance are rapidly progressing, and they can be used in a variety of occasions. This trend is currently continuing, and the batteries used in mobile terminals also need to be further miniaturized, thinned, lightened, and high-performance.

A non-aqueous electrolyte battery such as a lithium ion secondary battery is provided with a positive electrode and a negative electrode via a separator, and has properties such as LiPF ₆ , LiBF ₄ , and LiTFSI (lithium (bistrifluoromethylsulfonylimide)), LiFSI ( A structure in which a lithium salt of lithium (difluorosulfofluorenimide) is dissolved in an electrolytic solution of an organic liquid such as ethylene carbonate and the like is stored in a container.

The negative electrode and the positive electrode are usually electrode pastes obtained by dissolving or dispersing a binder and a thickener in water or a solvent, mixing an active material with the binder, and optionally a conductive auxiliary agent (conductivity imparting agent) and the like. A body (hereinafter sometimes referred to simply as a slurry) is applied to a current collector, dried with water or a solvent, and formed as a mixed layer. More specifically, for example, the negative electrode is a carbonaceous material capable of occluding and releasing lithium ions as an active material, and if necessary, acetylene black, which is a conductive additive, is used for a secondary battery electrode in a current collector such as copper. Adhesives that bind them together. On the other hand, the positive electrode is made of LiCoO ₂ or the like as an active material, and if necessary, a conductive auxiliary agent similar to that of the negative electrode, and a secondary battery electrode binder is used for a current collector such as aluminum to be bonded to each other.

In recent years, from the viewpoint of reducing the load on the environment and the simplicity of manufacturing equipment, there has been an increase in interest from a slurry using a solvent to a slurry using water, and in particular, the negative electrode system has been rapidly transferred.

As a binder for aqueous media, the most common user in the industry is to add carboxymethyl cellulose and sodium salt (CMC-Na) as a thickener to diene rubbers such as styrene-butadiene rubber (SBR). Series (for example, Patent Document 1). However, diene rubbers such as styrene-butadiene rubber have a problem of low adhesion to metal collectors such as copper, and the use amount cannot be reduced in order to improve the adhesion between the collector and the electrode material. In addition, there is also a problem that it is easily affected by heat generated during charge and discharge, and the capacity retention rate is low. Furthermore, since it is a two-liquid system, there are also problems in manufacturing with low storage stability and complicated slurry manufacturing steps.

In order to eliminate the problem of the SBR / CMC-Na addition system, the development of acrylic adhesives such as polyacrylic acid (for example, Patent Document 2) or polyamines / fluorimide-based adhesives (for example, Patent Document 3).

From the viewpoint of exhibiting high adhesiveness and low swelling property with respect to an electrolytic solution, an acrylic adhesive is excellent. On the other hand, there are problems that the resistance is high, the flexibility is insufficient, and the electrode is easily broken. Regarding the flexibility, for example, there have been reports of improvement in the introduction of a nitrile group as in Patent Document 4, but the resistance tends to be high.

In addition, polyamidoamine / amimine-based adhesives also exhibit high adhesiveness, and are particularly excellent in electrical properties, thermal stability, and mechanical strength. The subject is the same as the acrylic adhesive. Examples include high electrical resistance, lack of flexibility, and susceptibility to electrode breakage. However, it has been reported that the electrode swells with the insertion and removal of lithium ions during charge and discharge by utilizing mechanical strength. An example of a metal oxide with a large shrinkage used as a negative electrode active material to supplement flexibility (for example, Patent Document 5). However, the combination of polyamide / fluorimide-based adhesives and metal oxides cannot sufficiently eliminate the problems of high electrical resistance and lack of flexibility. In addition, polyamine / fluorimide-based adhesives also have difficulty in being expensive. .

Recently, there has been an increase in the use time of mobile terminals or the reduction in charging time. In particular, the increase in battery capacity (lower resistance, higher efficiency), life (cycle characteristics), and charging speed (rate characteristics) have increased. Top priority.

In non-aqueous electrolyte batteries, the capacity of the battery is affected by the amount of active material, so it is effective to increase the amount of active material in the limited space of the battery, and to suppress the amount of binder and thickener. Since the rate characteristics are also affected by the ease with which electrons can move, the amount of a binder and a thickener that suppresses non-conductivity and hinders the movement of electrons is effective. However, if the amount of the binder and the thickener is reduced, the binding property between the collector and the electrode material and the active material in the electrode is reduced, and not only the durability (battery life) is significantly reduced compared to long-term use, but also The electrodes are also brittle. In this way, it has been difficult to improve the battery characteristics such as battery capacity and the like while maintaining the combination of the collector and the electrode material and maintaining the toughness as an electrode.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to realize the function as a binder, that is, not to impair the binding property with the active material and the collector and the toughness as the electrode, and to improve the non-aqueous electrolyte battery. Battery characteristics (higher efficiency).

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2014-13693

[Patent Document 2] Japanese Patent Laid-Open No. 2002-260667

[Patent Document 3] Japanese Patent Laid-Open No. 2001-68115

[Patent Document 4] Japanese Patent Laid-Open No. 2003-282061

[Patent Document 5] Japanese Patent Laid-Open No. 2015-65164

As a result of careful research by the inventors of the present invention in order to solve the above-mentioned problems, it was found that the above-mentioned object can be achieved by using a binder composition for a non-aqueous electrolyte battery having the following structure, and further repeated discussions based on this knowledge have led to completion of the present invention.

That is, an adhesive composition for a non-aqueous electrolyte battery according to one aspect of the present invention (hereinafter simply referred to as an adhesive composition) is characterized by including (A) polyvinyl alcohol and (B) selected from vinyl alcohol At least one of a copolymer with an ethylenically unsaturated carboxylic acid and a neutralization salt thereof.

    [Form of Implementing Invention]    

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

The adhesive composition for a non-aqueous electrolyte battery according to this embodiment (hereinafter simply referred to as an adhesive composition) is characterized in that it includes the following (A) and (B): (A) polyvinyl alcohol and (B) selected from At least one of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralizing salt thereof.

According to the above configuration, a binder composition for a non-aqueous electrolyte battery having bonding properties and toughness can be obtained, and further use thereof can improve the battery characteristics (higher efficiency) of the non-aqueous electrolyte battery.

The content of the polyvinyl alcohol as the component (A) in the adhesive composition of this embodiment is not particularly limited, but is preferably 50% by weight or less, more preferably 40% by weight or less, and even more preferably 30% by weight. %the following. The lower limit of the content of the polyvinyl alcohol 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 the component (A) exceeds 50% by weight, the resistance may increase, and a high charge-discharge efficiency may not be obtained. If it is less than 1% by weight, the stability of the slurry may be deteriorated.

By containing polyvinyl alcohol as the component (A), the effect of improving the cohesiveness of the adhesive by the carboxyl group and the affinity of the collector and improving the adhesion can be expected. In addition, by mixing different polymers, the molecular weight distribution is broadened in appearance, and the crystallinity of the polymer is reduced. Therefore, the effect of improving the flexibility can be expected. In addition, by utilizing the intermolecular interaction of heterogeneous polymers to suppress agglomeration in a homopolymer, an effect of improving the stability of a slurry can be expected.

In this embodiment, the saponification degree of polyvinyl alcohol is also not particularly limited, but it is usually 50 mol% or more, more preferably 80 mol% or more, and still more preferably 95 mol% or more. When the degree of saponification is low, the alkali metal contained in the adhesive composition is hydrolyzed and the stability is unstable, which is not preferable.

In this embodiment, the ethylenically unsaturated carboxylic acid constituting the component (B) includes, for example, ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, methyl methacrylate, ethyl ester, and crotonic acid. , Fumaric acid, itaconic acid, maleic acid and other ethylenically unsaturated dicarboxylic acids. Among these, acrylic acid, methacrylic acid, and maleic acid are preferable from the viewpoints of availability, polymerization, and stability of products. These ethylenically unsaturated carboxylic acid esters may be used alone or in combination of two or more.

The content ratio of the vinyl alcohol and the ethylenically unsaturated carboxylic acid in the copolymer of the component (B) of the present embodiment is preferably in the range of 100/1 to 1/100 in terms of mole ratio. This is because the advantages of hydrophilicity, water solubility, and affinity for metals or ions as high polymers dissolved in water are obtained. When the ethylenically unsaturated carboxylic acid is too small, adhesion and flexibility are reduced, and when the ethylenically unsaturated carboxylic acid is too large, thermal and electrical stability are reduced.

(B) in the copolymer according to this embodiment is selected from at least one of a vinyl alcohol and an ethylenically unsaturated carboxylic acid copolymer and a neutralization salt thereof, and a copolymerization form thereof is not particularly limited, and random copolymerization may be mentioned , Cross copolymerization, block copolymerization, graft copolymerization, etc. In particular, in order to obtain high adhesiveness, block copolymerization and graft copolymerization of vinyl alcohol regularly arranged are preferred. From the viewpoint of having both adhesiveness and flexibility, a graft copolymer is more preferred.

The method for producing the copolymer of this embodiment is also not particularly limited, and may be any polymerization initiation method such as anionic polymerization, cationic polymerization, and radical polymerization. As a method for producing the polymer, solution polymerization, block polymerization, Any method such as suspension polymerization, dispersion polymerization, or emulsion polymerization.

The component (B) of this embodiment is at least one selected from the group consisting of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralization salt thereof, and the mass of the ethylenically unsaturated carboxylic acid is preferably 0.1 to 0.1. About 60 mol%. According to the foregoing, there are advantages that toughness and low electrical resistance can be imparted. The better quality of ethylenically unsaturated carboxylic acid is about 1 ~ 40 mole%. The quality of the ethylenically unsaturated carboxylic acid in this embodiment can be quantified by, for example, nuclear magnetic resonance spectroscopy (NMR).

From the viewpoint of heat resistance, the mass of the ethylenically unsaturated carboxylic acid is preferably less than 20 mole%, and more preferably less than 15 mole%. From the viewpoint of improving low resistance, it is also preferable to change the mass of the ethylenically unsaturated carboxylic acid to 11 mol% or more.

The average molecular weight of the copolymer of this embodiment is preferably a number average molecular weight of 5,000 to 250,000. When the number average molecular weight of the copolymer is less than 5,000, the mechanical strength of the adhesive may decrease. The number average molecular weight is more preferably 10,000 or more, and still more preferably 15,000 or more. On the other hand, when the number average molecular weight of the copolymer exceeds 250,000, the viscosity stability of the slurry composition for a non-aqueous electrolyte battery may decrease, and handling properties such as slurry aggregation may become insufficient. The number average molecular weight is more preferably 200,000 or less, and still more preferably 150,000 or less. In addition, the number average molecular weight of the copolymer in the present invention means that it is measured by a colloidal permeation chromatography (GPC) method using polyethylene oxide and polyethylene glycol as standard materials and using a water-based column as a column. Value.

In the present embodiment, the neutralized salt of the copolymer is preferably an active hydrogen of a carboxylic acid generated from an ethylenically unsaturated carboxylic acid and a basic substance which react to form a salt and become a neutralizer. In the (B) vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer and / or its neutralized salt used in this embodiment, it is preferable to use a monovalent metal from the viewpoint of the binding property as a binder. An alkaline substance and / or ammonia are used as the aforementioned alkaline substance.

Examples of the alkaline substance containing a monovalent metal usable 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. Carbonates; acetates of alkali metals such as sodium acetate and potassium acetate; phosphates of alkali metals such as trisodium phosphate. Among these, ammonia, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferred. In particular, as a binder for a lithium ion secondary battery, ammonia and lithium hydroxide are preferably used. The basic substance and / or ammonia containing a monovalent metal may be used alone or in combination of two or more kinds. In addition, as long as it does not adversely affect the battery performance, a neutral substance may be prepared by using an alkaline substance such as a hydroxide containing an alkali metal such as sodium hydroxide in combination.

The degree of neutralization is not particularly limited, but when used as a binder, considering the reactivity with the electrolytic solution, it is usually preferably in the range of 0.1 to 1 equivalent to the carboxylic acid generated from the ethylenically unsaturated carboxylic acid. It is more preferable to use a neutralizer in the range of 0.3 to 1 equivalent. As long as the degree of neutralization is as described above, there is an advantage that the acidity is low and decomposition of the electrolytic solution is suppressed.

In this embodiment, the method for determining the degree of neutralization may be a method using alkali titration, infrared spectrum, NMR spectrum, or the like. However, for simple and accurate measurement of the neutralization point, titration with alkali is preferred. The specific titration method is not particularly limited, but it can be dissolved in water with few impurities such as ion-exchanged water, and neutralized with alkaline substances such as lithium hydroxide, sodium hydroxide, and potassium hydroxide. The indicator of the neutralization point is not particularly limited, but an indicator such as phenolphthalein can be used for pH indication using an alkali.

In this embodiment, the usage amount of the alkaline substance and / or ammonia containing a monovalent metal is not particularly limited, and can be appropriately selected depending on the purpose of use and the like, and it is usually preferably relative to the ethylenically unsaturated carboxylic acid unit. The amount is 0.1 to 1 equivalent. Furthermore, if the amount of the basic substance containing a monovalent metal is used, it is preferably set to 0.3 to 1.0 equivalent, and more preferably set to 0.4 to 1.0 equivalent with respect to the maleic acid unit in the maleic acid copolymer. Amount of water can obtain a water-soluble copolymer salt with little alkali residue.

In this embodiment, the reaction of (B) vinyl alcohol with an ethylenically unsaturated carboxylic acid copolymer and / or a neutralized salt thereof can be performed according to a conventional method, but it is performed in the presence of water, and the neutralized product is used as an aqueous solution. The obtained method is simple and preferable.

The content of the vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer and / or its neutralized salt as the component (B) in the adhesive composition of this embodiment is not particularly limited, but is preferably 99.9% by weight or less. It is more preferably 99.5% by weight or less, and still 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, even more preferably 70% by weight or more, and particularly preferably 80% by weight or more. If the content of the component (B) exceeds 99.9% by weight, the stability of the slurry may be deteriorated. If the content is less than 50% by weight, the resistance may increase, and high charge-discharge efficiency may not be obtained.

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

The binder composition according to this embodiment is generally used as an aqueous binder solution for a non-aqueous electrolyte battery containing the above-mentioned binder composition and water.

The binder composition for a non-aqueous electrolyte battery according to this embodiment is generally preferably a slurry composition for a non-aqueous electrolyte battery (hereinafter simply referred to as a slurry) in addition to the binder composition described above, which further contains an active material and water. Body composition). That is, the slurry composition of this embodiment contains the above-mentioned binder composition of this embodiment, an active material, and water.

In this embodiment, the electrode for a non-aqueous electrolyte battery 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 a current collector, and then removing the solvent by a method such as drying. In the aforementioned mixed layer, a tackifier, a conductive aid, and the like may be further added as necessary.

In the aforementioned slurry composition for a non-aqueous electrolyte battery, the amount of the binder composition used when the weight of the active material is set to 100 is usually preferably 0.1 to 15% by weight, and more preferably 0.5 to 10% by weight. It is more preferably 1 to 8% by weight. If the amount of the binder composition is too small, the viscosity of the slurry may be too low and the thickness of the mixed layer may be reduced. If the amount of the binder composition is too large, the discharge capacity may be reduced.

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

As the solvent in the slurry composition of the present embodiment, in addition to the water described above, for example, alcohols such as methanol, ethanol, propanol, and 2-propanol, tetrahydrofuran, and 1,4-dioxane can be used. Cyclic ethers such as alkane, amines such as N, N-dimethylformamide, N, N-dimethylacetamide, and rings such as N-methylpyrrolidone and N-ethylpyrrolidone Sulfaamines, sulfenylamines, etc. Among these, water is preferably used from the viewpoint of safety.

In addition, as the solvent of the slurry composition of the present embodiment, in addition to water, the organic solvent shown below can be used in combination in a range of preferably 20% by weight or less of the entire solvent. As the aforementioned organic solvent, those having a boiling point of 100 ° C. to 300 ° C. at normal pressure are preferred, and examples thereof include hydrocarbons such as n-dodecane; 2-ethyl-1-hexanol and 1-nonanol Other alcohols; γ-butyrolactone, methyl lactate and other esters; N-methylpyrrolidone, N, N-dimethylacetamide, dimethylformamide and other amines; dimethyl Organic dispersing media such as Asiatic and Cymbidium, etc.

When the slurry composition of this embodiment is used for a negative electrode, examples of the negative electrode active material added to the slurry composition include amorphous carbon, graphite, natural graphite, mesocarbon microspheres (MCMB), Carbonaceous materials such as pitch-based carbon fibers; conductive polymers such as polyacene; composite metal oxides such as SiOx, SnOx, and LiTiOx; other metal oxides; lithium-based metals such as lithium metals, and lithium alloys; TiS ₂ , LiTiS ₂ and other metal compounds.

When the slurry composition of this embodiment is used for a positive electrode, examples of the positive electrode active material added to the slurry composition include lithium iron phosphate (LiFePO ₄ ), lithium manganese phosphate (LiMnPO ₄ ), and phosphoric acid. Cobalt lithium (LiCoPO ₄ ), iron pyrophosphate (Li ₂ FeP ₂ O ₇ ), lithium cobalt complex oxide (LiCoO ₂ ), spinel type lithium manganese composite oxide (LiMn ₂ O ₄ ), lithium manganese composite oxide (LiMnO ₂ ), lithium nickel composite oxide (LiNiO ₂ ), lithium niobium composite oxide (LiNbO ₂ ), lithium iron composite oxide (LiFeO ₂ ), lithium magnesium composite oxide (LiMgO ₂ ), lithium calcium composite oxide (LiCaO ₂ ), lithium copper composite oxide (LiCuO ₂ ), lithium zinc composite oxide (LiZnO ₂ ), lithium molybdenum composite oxide (LiMoO ₂ ), lithium group composite oxide (LiTaO ₂ ), lithium tungsten 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 system Ni - Co - manganese complex oxide (LixNiACoBMnCO ₂ solid solution), nickel-manganese oxide _{(LiNi 0.5 Mn 1.5 O 4)} , manganese oxide (MnO _2), vanadium oxides, sulfur oxides, silicate Department of oxides.

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, unsaturated carboxylic acids and their modifiers, α-olefin-maleic acids and their modifiers, celluloses, and starch polysaccharides can be used. .

In response to the amount of the thickener blended with the slurry composition, when the weight of the active material is 100, it is preferably about 0.1 to 4% by weight, more preferably 0.3 to 3% by weight, and even more preferably 0.5 to 2% by weight. When the amount of the thickener 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. Conversely, when the amount of the thickener is too large, the discharge capacity may be reduced.

Examples of the conductive auxiliary agent to be blended in accordance with the slurry composition include metal powder, conductive polymer, and acetylene black. When the amount of the conductive auxiliary is 100, the weight of the active material is usually preferably 0.1 to 10% by weight, and more preferably 0.8 to 7% by weight.

As described above, in this embodiment, the electrode for a non-aqueous electrolyte battery is characterized in that a current collector is combined with a mixed layer including at least the binder composition and the active material of this embodiment. The current collector used for the negative electrode of the non-aqueous electrolyte battery of this embodiment is not particularly limited as long as it is made of a conductive material, and for example, iron, copper, aluminum, nickel, stainless steel, titanium, group, gold , Platinum and other metal materials. These may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

In particular, when copper is used as a current collector for a negative electrode, the effect of the slurry for a negative electrode of a non-aqueous electrolyte battery of the present invention is best exhibited. This is because the adhesive composition of this embodiment has high affinity with copper foil, and a negative electrode having high adhesion can be produced. 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.

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 is best exhibited. This is because the adhesive composition of this embodiment has high affinity with aluminum foil, and a negative electrode having high adhesion can be produced. 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, a dipping method, a reverse roll method, a direct roll method, a gravure method, an extrusion method, a dipping method, and a brush coating method. The amount of coating is also not particularly limited, but in general, the thickness of the mixed layer containing the active material, the conductive additive, the adhesive, and the thickener formed after removing the solvent or dispersant by a method such as drying is preferred. The amount is 0.005 to 5 mm, and more preferably 0.01 to 2 mm.

There is no particular limitation on the drying method for solvents such as water contained in the slurry composition, and examples thereof include aeration drying using warm air, hot air, and low-humidity wind; vacuum drying; infrared, far infrared, and electron beam drying such as irradiation Wait. Drying conditions are adjusted within a speed range that is such a degree that cracks in the active material layer are caused by stress concentration and the active material layer does not peel from the current collector, and the solvent can be removed as soon as possible. Furthermore, in order to increase the density of the active material of the electrode, it is effective to pressurize the dried current collector. Examples of the pressing method include methods such as die pressing and roller pressing.

The present invention also includes a non-aqueous electrolyte battery including the electrode. Non-aqueous electrolyte batteries usually include a negative electrode, a positive electrode, and an electrolytic solution.

When the binder composition of this embodiment is used for the positive electrode, the negative electrode is not particularly limited, and a negative electrode generally used in a non-aqueous electrolyte battery such as a lithium ion secondary battery can be used. For example, as the negative electrode active material, graphite, hard carbon, Si-based oxide, or the like can be used. In addition, the negative electrode active material, the conductive auxiliary agent shown above, and SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, and other binders can be mixed in water or the above. A negative electrode slurry prepared by a solvent having a boiling point of 100 ° C. or higher and 300 ° C. or lower at normal pressure, for example, is applied to a negative electrode current collector such as a copper foil, and the solvent is dried to form a negative electrode.

When the binder composition of this embodiment is used for the negative electrode, the positive electrode is not particularly limited, and a positive electrode generally used in a non-aqueous electrolyte battery such as a lithium ion secondary battery can be used. 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 and the like are used. Transition metal oxides or lithium-containing composite metal oxides such as LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , and LiMn ₂ O ₄ . In addition, the positive electrode active material, the conductive auxiliary agent described above, and binders such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinylidene fluoride can be mixed with water or the above. The positive electrode slurry prepared by a solvent having a boiling point of 100 ° C. or higher and 300 ° C. or lower at normal pressure is applied to a positive electrode current collector such as aluminum, and the solvent is dried to form a positive electrode.

An electrode including the binder composition of the present embodiment can be used for either the positive electrode or the negative electrode.

In the non-aqueous electrolyte battery of this embodiment, an electrolytic solution in which an electrolyte is dissolved in a solvent can be used. The electrolytic solution may be in a liquid state or a gel state as long as it is used for a non-aqueous electrolyte battery such as a lithium ion secondary battery, and it may be appropriately selected and used depending on the type of the negative electrode active material and the positive electrode active material. The battery function is sufficient. As a specific electrolyte, for example, any conventionally known lithium salt can be used, and examples include LiClO ₄ , LiBF ₆ , LiPF ₆ , LiCF ₃ SO ₃ , LiCF ₃ CO ₂ , LiAsF ₆ , LiSbF ₆ , 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, etc.

The solvent (electrolytic solution solvent) for dissolving the electrolyte is not particularly limited. Specific examples include carbonates such as propylene carbonate, ethylene carbonate, butene carbonate, dimethyl carbonate, and diethyl carbonate; lactones such as γ-butyrolactone; and trimethoxymethane , 1,2-dimethoxyethane, diethyl ether, 2-ethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran and other ethers; dimethylsulfinium and other ethers; 1,3-bis Oxetanes such as oxetane, 4-methyl-1,3-dioxane; nitrogen compounds such as acetonitrile or nitromethane; methyl formate, methyl acetate, Organic acid esters such as ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate; inorganic acid esters such as triethyl phosphate, dimethyl carbonate, and diethyl carbonate; diethylene glycol di Methyl ethers; triethylene glycol dimethyl ethers; cyclobutanes; 3-methyl-2- Azolidone Zolidones; sultones such as 1,3-propanesultone, 1,4-butanesultone, and naphthalenesultone, etc. These can be used alone or in combination of two or more. 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 the present embodiment is not particularly limited, and examples thereof include the following manufacturing methods. That is, the negative electrode and the positive electrode are stacked with a separator such as a polypropylene porous membrane, and are rolled, folded, or the like according to the shape of the battery, put into a battery container, and filled with an electrolytic solution and sealed. The shape of the battery can also be any known coin type, button type, sheet type, cylindrical type, square type, flat type, and the like.

The non-aqueous electrolyte battery of the present embodiment is a battery capable of improving both adhesion and battery characteristics, and is useful for various applications. For example, it is also very useful as a battery used in mobile terminals that require miniaturization, thinness, weight reduction, and high performance.

In this specification, various techniques are disclosed as described above, and the main techniques are summarized below.

One aspect of the present invention is a binder composition for a non-aqueous electrolyte battery, which comprises (A) polyvinyl alcohol and (B) selected from a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and its neutralization. At least one kind of salt.

According to such a configuration, it is considered that the battery characteristics can be improved without impairing the binding property with the active material and the collector and the toughness as an electrode.

In the adhesive composition, it is preferred that the (B) is at least one selected from the group consisting of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralization salt thereof, and is copolymerized in the form of block copolymerization. . From the foregoing, it is considered that higher adhesion can be obtained.

Further, in the adhesive composition, it is preferred that the (B) is at least one selected from the group consisting of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralization salt thereof, and is copolymerized in the form of graft copolymerization. polymerization. From the foregoing, it is considered that both adhesiveness and flexibility can be achieved.

Moreover, in the said adhesive composition, it is preferable that the said (B) is an ethylene unsaturated carboxylic acid modified from at least 1 type of the copolymer of a vinyl alcohol and an ethylenically unsaturated carboxylic acid, and its neutralization salt. It is 0.1 to 60 mole%. From the foregoing, it is considered that toughness and low electrical resistance can be imparted.

The content of the component (B) in the adhesive composition is preferably 50.0 to 99.9% by weight. From the foregoing, it can be considered that slurry stability or higher charge-discharge efficiency can be obtained.

In another aspect of the present invention, a binder aqueous solution for a non-aqueous electrolyte battery is characterized by containing the binder composition and water.

In another aspect of the present invention, a slurry composition for a non-aqueous electrolyte battery is characterized by containing the above-mentioned binder composition, an active material, and water.

In another aspect of the present invention, an electrode for a non-aqueous electrolyte battery is characterized in that a current collector is combined with a mixed layer containing the binder composition and an active material.

A non-aqueous electrolyte battery according to another aspect of the present invention includes the above-mentioned electrode for a non-aqueous electrolyte battery.

    [Example]    

Examples of the present invention are 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 (manufactured by Kuraray Co., Ltd., 28-98s) was irradiated with an electron beam (30 kGy). Next, 33.4 g of acrylic acid and 466.6 g of methanol were added to a reactor equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, and a particle addition port, and nitrogen was substituted in the system for 30 minutes while bubbling nitrogen gas. Here, 100 g of polyvinyl alcohol irradiated with electron beam was added and stirred, and the particles were dispersed in the solution and heated under reflux for 300 minutes to perform graft polymerization. Then, it filtered, the particle was collect | recovered, and it dried under vacuum overnight at 40 degreeC, and obtained the objective copolymer. The mass of the ethylenically unsaturated carboxylic acid of the obtained copolymer was changed to 6.8 mol%.

    <Preparation of neutralization salt of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>    

To 100 g of a 10% by weight aqueous solution of the vinyl alcohol and acrylic copolymer obtained above, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer, and the mixture was heated and stirred at 80 ° C. for 2 hours, and then cooled to room temperature.

    <Adjustment of Binder Aqueous Solution>    

To the 10% by weight aqueous solution (B-1) of the neutralized salt of the vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer obtained above, a commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., 28-98s, Saponification degree: 98) (A-1), and the weight ratio was set to (A-1): (B-1) = 10: 90 in terms of solid content, and the binder aqueous solution was adjusted.

    <Determination of melting point of neutralized salt of vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer>    

1 g of the above-mentioned binder aqueous solution was dried in a hot air dryer at 105 ° C. for 1 hour, and the obtained solid was used to perform differential scanning calorimetry using a thermal analyzer (manufactured by Yamato Scientific Co., Ltd.). The measurement was performed at a measurement temperature range of 50 ° C to 1000 ° C and a temperature increase rate of 10 ° C / min. The results are shown in Table 1 below.

    <Making of Slurry>    

The electrode slurry is produced by using a 10% by weight aqueous solution of the aforementioned binder composition in an amount of 3 parts by weight with respect to 96 parts by weight of natural graphite (manufactured by DMGS, BYD) as an active material for the negative electrode, and solids. 1 part by weight of Super-P (manufactured by TIMCAL) as a conductive additive (conductivity imparting agent) is put into a special container, and a planetary mixer (ARE-250, manufactured by THINKY) is used for kneading to prepare an electrode coating slurry body. The composition ratio of the active substance and the binder in the slurry is based on the solid content. Graphite powder: conductive additive: binder composition = 96: 1: 3 (weight ratio).

    <Stability of Slurry>    

In order to confirm the stability of the obtained slurry, it was visually confirmed that the particles precipitated immediately after the slurry was prepared (within 30 minutes). The slurry which did not precipitate was described as (circle), and the slurry which precipitated was described as (x). The results are shown in Table 1 below.

    <Production of negative electrode for battery>    

The obtained slurry was coated on a copper foil (CST8G, Fukuda Metal Foil Industrial Co., Ltd.) of a current collector using a bar coater (T101, manufactured by Matsuo Industries), and dried at 80 ° C for 30 minutes with a hot air dryer. After that, a roll treatment (manufactured by Baoquan) was used to perform a calendering process. After that, it was punched out as an electrode for a battery (φ14 mm), and then subjected to secondary drying under a reduced pressure condition of 140 ° C. for 3 hours to produce an electrode for a coin battery.

    <Production of electrode for peel strength and toughness test>    

The obtained slurry was coated on a copper foil (CST8G, Fukuda Metal Foil Industrial Co., Ltd.) of a current collector using a bar coater (T101, manufactured by Matsuo Industries), and dried at 80 ° C for 30 minutes with a hot air dryer. Then, the test was performed using the electrode (film thickness: about 40 micrometers) which performed the calendering process using a roller press (made by Baoquan).

    <Toughness test of electrode>    

The evaluation of the toughness of the electrode was performed by visually confirming whether a crack occurred when the electrode was folded using the aforementioned electrode for a toughness test with a width of 10 mm. An electrode where no cracking occurred was described as ○, and an electrode where cracking occurred was described as ×. The results are shown in Table 1 below.

    <Measurement of peeling strength of electrode>    

The strength at the time of peeling the said electrode for peeling strength test from the copper foil which is a collector was measured. The peel strength was measured at a 180 ° peel strength using a 50N load cell (manufactured by IMADA Co., Ltd.). The slurry-coated surface of the battery-coated electrode obtained above was bonded to a stainless steel plate using double-sided tape (double-sided tape made by Nichiban), and the 180 ° peel strength (peel width 10 mm, peel speed 100 mm / min) was measured. The results are shown in Table 1 below.

    <Making a Battery>    

The obtained negative electrode for a battery was transferred to a glove box (manufactured by Miwa Co., Ltd.) under an argon atmosphere. The positive electrode system uses a metal lithium foil (thickness: 0.2mm, φ16mm). In addition, a polypropylene-based separator (Celgard # 2400, manufactured by Polypore) was used as the separator, and the electrolytic solution was vinyl carbonate (EC) and ethyl methyl carbonate (EMC) in lithium hexafluoride phosphate (LiPF ₆ ). A mixed solvent system (1M-LiPF ₆ , EC / EMC = 3 / 7vol%, VC 2% by weight) was added by adding vinylene carbonate (VC) to make a coin battery (type 2032).

    <Charge and discharge characteristics test>    

The coin cell produced was subjected to a charge-discharge test using a commercially available charge-discharge tester (TOSCAT3100, manufactured by Toyo System). The coin cell was placed in a constant temperature bath at 25 ° C. The lithium potential was charged until it reached 0V, and the active material mass was charged at a constant current of 0.1C (about 0.5 mA / cm ² ), and the lithium potential was fixed at 0V. The voltage is charged to a current of 0.02 mA. Let the capacity at this time be the charging capacity (mAh / g). Next, the lithium potential was discharged at a constant current of 0.1 C (about 0.5 mA / cm ² ) to 1.5 V, 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 results are shown in Table 1 below.

    (Example 2)    

A vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer was synthesized by the same method as in Example 1. Furthermore, 1.0 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer, and the neutralization salt (B-2) of the copolymer was prepared. Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and its weight ratio was (A-1) :( B-2) = 10: 90 based on solid content, and an aqueous binder solution was performed. Of adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 3)    

Except having added 100g of acrylic acid and 400g of methanol, it carried out similarly to Example 1, and synthesize | combined the objective copolymer. The ethylene unsaturated carboxylic acid of the obtained copolymer was changed to 26.2 mol%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-3) of the said copolymer was prepared. Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and its weight ratio was (A-3) :( B-3) = 7: 93 based on solid content, and an aqueous binder solution was performed. Of adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 4)    

An electron beam (30 kGy) was irradiated to 100 g of commercially available polyvinyl alcohol (Kuraray Co., Ltd., 22-88s). Next, 33.5 g of acrylic acid and 466.5 g of methanol were added to a reactor equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, and a particle addition port, and nitrogen was replaced in the system for 30 minutes while nitrogen was bubbled. Here, 100 g of polyvinyl alcohol irradiated with electron beam was added and stirred, and the particles were dispersed in the solution and heated under reflux for 300 minutes to perform graft polymerization. Thereafter, filtration was performed to recover the particles, and vacuum drying was performed at 40 ° C overnight to obtain the intended copolymer. The mass of the ethylenically unsaturated carboxylic acid of the obtained copolymer was changed to 7.1 mol%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-4) of the said copolymer was prepared. After that, a commercially available polyvinyl alcohol (made by Kuraray Co., Ltd., 22-88s, degree of saponification: 88) (A-2) was added, and the weight ratio was (A-2): (B-4) in terms of solid content. = 10: 90, adjust the binder aqueous solution.

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

    (Example 5)    

An electron beam (30 kGy) was irradiated to 100 g of commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Elvanol 71-30). Next, 25 g of methacrylic acid and 475 g of methanol were added to a reactor equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, and a particle addition port, and nitrogen was bubbled through the system while nitrogen was substituted in the system for 30 minutes. Here, 100 g of polyvinyl alcohol irradiated with electron beam was added and stirred, and the particles were dispersed in the solution and heated under reflux for 300 minutes to perform graft polymerization. Thereafter, filtration was performed to recover the particles, and vacuum drying was performed at 40 ° C overnight to obtain the intended copolymer. The mass of the ethylenically unsaturated carboxylic acid of the obtained copolymer was changed to 7.0 mol%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-5) of the said copolymer was prepared. After that, a commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Elvanol 71-30, degree of saponification: 99) (A-3) was added, and the weight ratio was (A-3): (B-5) in terms of solid content. ) = 12: 88, adjust the binder aqueous solution.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced in the same manner as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 6)    

Except that 100 g of methacrylic acid and 400 g of methanol were added, the copolymer was synthesized in the same manner as in Example 5 to synthesize the intended copolymer. The mass of the ethylenically unsaturated carboxylic acid of the obtained copolymer was changed to 34.0 mol%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-6) of the said copolymer was prepared. Then, the same commercially available polyvinyl alcohol (A-3) as in Example 5 was added, and the weight ratio was set to (A-3): (B-6) = 5:95 based on the solid content, and an aqueous binder solution was then prepared. Adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 7)    

In a reactor equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, and an initiator addition port, 370 g of water and 100 g of a commercially available polyvinyl alcohol (manufactured by Kuraray Co., Ltd., M115) were added and stirred at 95 ° C. After heating, this polyvinyl alcohol was dissolved and then cooled to room temperature. To this aqueous solution, 0.5 equivalent concentration (N) of sulfuric acid was added to adjust the pH to 3.0. Here, after adding 9.9 g of acrylic acid with stirring, the solution was heated to 70 ° C. while bubbling nitrogen gas into the aqueous solution. Then, while maintaining at 70 ° C, nitrogen was bubbled for 30 minutes, and nitrogen substitution was performed. After the nitrogen substitution, it took 1.5 hours, and 80.7 g of a potassium persulfate aqueous solution (concentration: 2.5% by weight) was dropped into this aqueous solution. After the total amount was added, the temperature was raised to 75 ° C., and after stirring for 1 hour, it was cooled to room temperature. The obtained aqueous solution was cast on a PET film, and dried by hot air at 80 ° C. for 30 minutes to prepare a film. This film was frozen with liquid nitrogen, pulverized with a centrifugal pulverizer, and vacuum-dried at 40 ° C. overnight to obtain the intended copolymer. The ethylene-unsaturated carboxylic acid of the obtained copolymer was changed to 6.0 mole%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-7) of the said copolymer was prepared. Then, the same commercially available polyvinyl alcohol (A-1) as in Example 1 was added, and the weight ratio was (A-1) :( B-7) = 10: 90 based on the solid content, and the aqueous binder solution was then prepared. Adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 8)    

A vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer was synthesized by the same method as in Example 7. Furthermore, 1.0 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer, and the neutralization salt (B-8) of the copolymer was prepared. Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and the weight ratio was (A-1) :( B-8) = 10: 90 based on the solid content, and an aqueous binder solution was prepared. Adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 9)    

Except adding 20 g of acrylic acid and 150 g of potassium persulfate aqueous solution (concentration 2.5% by weight), a vinyl alcohol and an ethylenically unsaturated carboxylic acid copolymer were synthesized by the same method as in Example 7. The mass of the ethylenically unsaturated carboxylic acid of the obtained copolymer was changed to 12.0 mol%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-9) of the said copolymer was prepared. Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and the weight ratio was (A-1) :( B-9) = 10: 90 based on the solid content, and an aqueous binder solution was prepared. Adjustment.

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

    (Example 10)    

A vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer was synthesized by the same method as in Example 9. In addition, 0.3 equivalent of sodium hydroxide was added to the carboxylic acid unit in the polymer, and 0.2 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer to prepare the neutralization salt (B-10) of the copolymer. . Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and the weight ratio was (A-1): (B-10) = 10: 90 based on the solid content, and an aqueous binder solution was prepared. Adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 11)    

In a reactor equipped with a stirrer, a reflux cooling tube, an argon introduction tube, and a starter addition port, 640 g of vinyl acetate, 240.4 g of methanol, and 0.88 g of acrylic acid were added, and nitrogen was bubbled into the system while nitrogen was introduced into the system. Replaces 30 minutes. Unlike the foregoing, 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 gas was bubbled for 30 minutes. The temperature of the reactor was started to increase the internal temperature to 60 ° C, and then 0.15 g of 2,2'-azobisisobutyronitrile was added to start polymerization. During the progress of the polymerization reaction, the prepared retardation solution was dropped into the system, so that the monomer composition (the molar ratio of vinyl acetate to acrylic acid) in the polymerization solution became constant. After polymerizing at 60 ° C for 210 minutes, cooling was performed to stop the polymerization. Next, methanol was occasionally added under reduced pressure at 30 ° C. and unreacted monomers were removed to obtain a methanol solution of polyvinyl acetate modified with acrylic acid. Next, methanol was added to the methanol solution of polyvinyl acetate, and 400 g of a methanol solution of polyvinyl acetate having a concentration of 25% by weight was added. 20.4 g of a sodium hydroxide methanol solution (18.0% by weight) and methanol were added. 79.6 g was saponified at 40 ° C. Since a colloid was formed several minutes after the sodium hydroxide methanol solution was added, it was pulverized with a pulverizer and left at 60 ° C for 60 minutes to perform saponification. The obtained pulverized rubber was repeatedly washed with methanol, and then vacuum-dried at 40 ° C. overnight to synthesize a copolymer for the purpose. The mass of the ethylenically unsaturated carboxylic acid of the obtained copolymer was changed to 5.0 mol%. Moreover, 0.5 equivalent of lithium hydroxide was added to the carboxylic acid unit in a polymer, and the neutralization salt (B-11) of the said copolymer was prepared. Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and the weight ratio was (A-1): (B-11) = 10: 90 based on the solid content, and an aqueous binder solution was prepared. Adjustment.

A slurry for a non-aqueous electrolyte battery was prepared in the same manner as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 12)    

The same neutralizing salt (B-11) as in Example 11 was used, and a commercially available polyvinyl alcohol (A-1) similar to that in Example 1 was added, and the weight ratio was (A-1) in terms of solid content: ( B-11) = 40: 60, adjust the aqueous binder solution.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Example 13)    

A vinyl alcohol and ethylenically unsaturated carboxylic acid copolymer was synthesized by the same method as in Example 11. Furthermore, 1.0 equivalent of lithium hydroxide was added to the carboxylic acid unit in the polymer, and the neutralization salt (B-13) of the copolymer was prepared. Then, the commercially available polyvinyl alcohol (A-1) used in Example 1 was added, and the weight ratio was (A-1): (B-13) = 10: 90 based on the solid content, and an aqueous binder solution was prepared. Adjustment.

A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Comparative example 1)    

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

    (Comparative example 2)    

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

    (Comparative example 3)    

A 10% by weight aqueous solution was prepared using the same neutralizing salt as in Example 1 and used as a binder composition. A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Comparative Example 4)    

A 10% by weight aqueous solution was prepared using the same neutralizing salt as in Example 7 and used as an adhesive composition. A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. In the same manner as in Example 1, a coated electrode for toughness test and peel strength was prepared, and the toughness test and peel strength measurement were performed using the same. The results are shown in Table 1 below.

    (Comparative example 5)    

A neutralizing salt similar to that in Example 11 was used to prepare a 10% by weight aqueous solution and used as a binder composition. A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. 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 an adhesive composition. A slurry for a non-aqueous electrolyte battery was produced by the same method as in Example 1 above, and the stability of the slurry was confirmed. In addition, a coated negative electrode for a battery was produced by the same method as in Example 1 to obtain a coin battery, and a charge-discharge characteristic test was performed. Then, a coated electrode for toughness test and peeling strength was produced in the same manner as in Example 1, and the toughness test and peeling strength measurement were performed using the same. The results are shown in Table 1 below.

    (Inspection)    

Examples 1 to 13 including the component (A) and the component (B) of the present invention show the effect of neutralizing the salt, and can achieve a high charge-discharge efficiency of 92% or more. The polymer salt is assumed to be able to easily move Li ions in the battery due to the application of a powdered active material to form an ionic conductive layer. In addition, by coexisting the (A) component and the (B) component with two or more components, improvement in slurry stability, toughness, and adhesion can be seen. In contrast, Comparative Examples 1 to 2 and 6 which did not include a neutralizing salt had low charge / discharge efficiency (less than 92%), and even results in low slurry stability, toughness, and adhesion.

In addition, like Examples, Comparative Examples 3 to 5 show high charge-discharge efficiency, but on the other hand, because of the low stability of the slurry, it is difficult to form a uniform electrode. Compared with the Examples, slurry stability, Toughness and adhesion are insufficient.

From the above, it is clear that by using the adhesive composition of the present invention, the binding properties of the electrode binder and the toughness of the electrode are not impaired, and the battery characteristics of the non-aqueous electrolyte battery can be improved.

This application is based on Japanese Patent Application No. 2017-50807, filed on March 16, 2017, and its contents are included in this application.

In order to present the present invention, while referring to specific examples and the like, the present invention will be appropriately and fully explained through embodiments. However, as long as it is a person with ordinary knowledge in the technical field, he or she can recognize that it can be easily changed and / or The aforementioned embodiment is improved. Therefore, as long as the form of change or improvement implemented by a person having ordinary knowledge in the technical field does not depart from the scope of rights described in the claims of the scope of patent application, the form of change or improvement is to be interpreted as including To the scope of the claim.

    [Industrial availability]    

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

Claims (9)

    A binder composition for a non-aqueous electrolyte battery, comprising (A) polyvinyl alcohol and (B) at least one selected from the group consisting of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralizing salt thereof.         The adhesive composition for a non-aqueous electrolyte battery according to claim 1, wherein the (B) is at least one selected from the group consisting of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralization salt thereof, and is block copolymerized. Copolymerization of morphology.         The adhesive composition for a non-aqueous electrolyte battery according to claim 1, wherein (B) is at least one selected from the group consisting of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralization salt thereof, and is graft copolymerized Copolymerization of morphology.         The adhesive composition for a non-aqueous electrolyte battery according to claim 1, wherein (B) is an ethylenically unsaturated carboxylic acid selected from at least one of a copolymer of vinyl alcohol and an ethylenically unsaturated carboxylic acid and a neutralizing salt thereof. The quality of acid change is 0.1 ~ 60 mol%.         The adhesive composition for a non-aqueous electrolyte battery according to claim 1, wherein the content of the component (B) in the adhesive composition is 50.0 to 99.9% by weight.         An aqueous binder solution for a non-aqueous electrolyte battery, comprising the binder composition according to any one of claims 1 to 5 and water.         A slurry composition for a non-aqueous electrolyte battery, comprising the binder composition according to any one of claims 1 to 5, an active material, and water.         An electrode for a non-aqueous electrolyte battery, which is formed by combining a mixed layer containing the binder composition according to any one of claims 1 to 5 and an active material with a current collector.         A non-aqueous electrolyte battery having the electrode for a non-aqueous electrolyte battery according to claim 8.