Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/26—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers modified by chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L79/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen with or without oxygen or carbon only, not provided for in groups C08L61/00 - C08L77/00
  • C08L79/02—Polyamines
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to a thickening stabilizer for a nonaqueous electrolyte battery electrode, a binder composition containing the same, a slurry composition for a nonaqueous electrolyte battery electrode, a nonaqueous electrolyte battery electrode, and a nonaqueous electrolyte battery.
• Lithium ion secondary batteries are frequently used as secondary batteries used for the power sources of these portable terminals. Since portable terminals are required to have more comfortable portability, miniaturization, thinning, weight reduction, and high performance have rapidly progressed, and have come to be used in various places. This trend continues today, and batteries used in mobile terminals are further required to be smaller, thinner, lighter, and higher in performance.
• a non-aqueous electrolyte battery such as a lithium ion secondary battery has a positive electrode and a negative electrode installed via a separator, and LiPF 6 , LiBF 4 LiTFSI (lithium (bistrifluoromethylsulfonylimide)), LiFSI (lithium (bisfluorosulfonylimide). )) And a lithium salt dissolved in an organic liquid such as ethylene carbonate in a container.
• the negative electrode and the positive electrode are usually a binder composition in which a binder and a thickening stabilizer are dissolved or dispersed in water, and an active material and, if necessary, a conductive additive (conductivity imparting agent) are mixed therewith.
• the electrode slurry (hereinafter, sometimes simply referred to as slurry) obtained in this manner is applied to a current collector and water is dried to form a mixed layer.
• a carbonaceous material that can store and release lithium ions which is an active material, and, if necessary, acetylene black as a conductive auxiliary agent, are used as a current collector such as copper. They are formed by binding with a secondary battery electrode binder.
• the positive electrode is formed by binding LiCoO 2 as an active material and, if necessary, a conductive aid similar to the negative electrode to a current collector such as aluminum using a binder for a secondary battery electrode.
• CMC-Na carboxymethylcellulose sodium salt
• the electrode since the binding between the collecting electrode, the electrode material, and the active material in the electrode is reduced, the electrode is brittle and the electrode yield is reduced, and the durability (battery life) for a long time use is remarkably increased. There is also a risk of decline. For these reasons, it has been difficult to reduce the resistance while maintaining the binding property between the collector electrode and the electrode material.
• the present invention has been made in view of the above-mentioned problems, and functions as a thickening stabilizer, i.e., improved binding properties with a collector electrode and a battery in a nonaqueous electrolyte battery without impairing active material dispersibility.
• the purpose is to reduce the internal resistance.
• the present inventors have found that the above object can be achieved by using a thickening stabilizer for a nonaqueous electrolyte battery having the following constitution, and further studies are made based on this finding. Thus, the present invention was completed.
• the thickening stabilizer according to one aspect of the present invention is characterized by containing a neutralized salt of an ⁇ -olefin-maleic acid copolymer obtained by copolymerizing an ⁇ -olefin and maleic acid and a polyamine.
• the “thickening stabilizer” for non-aqueous electrolyte batteries is not particularly limited, and is a slurry viscosity that is dissolved or dispersed in water to express its function and is suitable for coating. It has a function as a viscosity adjusting agent for adjusting to a region and a function as a dispersing agent for uniformly dispersing an active material in a solvent.
• the thickening stabilizer for a nonaqueous electrolyte battery according to this embodiment is characterized by containing a neutralized salt of an ⁇ -olefin-maleic acid copolymer obtained by copolymerizing an ⁇ -olefin and a maleic acid, and a polyamine. To do.
• the binder for a non-aqueous electrolyte battery having binding properties and low resistance without impairing the dispersibility of the active material in the electrode slurry.
• a composition can be obtained. Furthermore, the internal resistance reduction of a nonaqueous electrolyte battery is realizable using it.
• an ⁇ -olefin-maleic acid copolymer obtained by copolymerizing an ⁇ -olefin and maleic acid is composed of a unit (A) based on ⁇ -olefin and a unit (B) based on maleic acid,
• a linear random copolymer having an average molecular weight of 10,000 to 500,000 is preferable.
• the unit (A) based on ⁇ -olefins is represented by the general formula —CH 2 CR 1 R 2 — (wherein R 1 and R 2 may be the same or different from each other, hydrogen Represents an alkyl group having 1 to 10 carbon atoms, an alkenyl or aryl group, an ether group, or a silyl group).
• the ⁇ -olefin used in this embodiment is a linear or branched olefin having a carbon-carbon unsaturated double bond at the ⁇ -position. In particular, olefins having 2 to 12 carbon atoms, particularly 2 to 8 carbon atoms are preferred.
• Representative examples that can be used include ethylene, propylene, n-butylene, isobutylene, n-pentene, isoprene, 2-methyl-1-butene, 3-methyl-1-butene, n-hexene, 2-methyl- 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-butene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethylbutadiene, 2,5 -Pentadiene, 1,4-hexadiene, 2,2,4-trimethyl-1-pentene, styrene, ⁇ -methylstyrene, paramethylstyrene, methyl vinyl ether, ethyl vinyl ether and the like.
• isobutylene ethylene
• methyl vinyl ether are particularly preferred from the viewpoints of availability, polysynthesis, and product stability.
• the isobutylene includes a mixture containing isobutylene as a main component, for example, a BB fraction (C4 fraction).
• BB fraction C4 fraction
• These olefins may be used alone or in combination of two or more.
• maleic anhydride maleic acid, maleic acid monoester (for example, methyl maleate, ethyl maleate, propyl maleate, phenyl maleate, etc.), maleic acid, as the unit (B) based on maleic acids
• Maleic anhydride derivatives such as diesters (eg dimethyl maleate, diethyl maleate, dipropyl maleate, diphenyl maleate etc.), maleic imides or N-substituted derivatives thereof (eg maleic imide, N-methylmaleimide, N N-substituted alkylmaleimides such as ethylmaleimide, N-propylmaleimide, Nn-butylmaleimide, Nt-butylmaleimide, N-cyclohexylmaleimide, N-methylphenylmaleimide, N-ethylphenylmaleimide N-substituted alkylphenylmaleimide such as imide, or N-
• maleic anhydride is preferable from the viewpoint of availability, polymerization rate, and ease of molecular weight adjustment.
• These maleic acids may be used alone or in combination.
• Maleic acids are neutralized with alkali salts as described above, and the resulting carboxylic acid and carboxylic acid salt form a 1,2-dicarboxylic acid or salt form. This form has a function of capturing heavy metals eluted from the positive electrode.
• the content ratio of each structural unit in the copolymer of the present embodiment is preferably such that (A) / (B) is in the range of 1/1 to 1/3 in terms of molar ratio. This is because the advantages of hydrophilicity, water solubility, and affinity for metals and ions as a high molecular weight substance that dissolves in water can be obtained. Particularly, it is desirable that the molar ratio of (A) / (B) is 1/1 or a value close thereto, in which case the unit based on ⁇ -olefin, that is, —CH 2 CR 1 R 2 — A copolymer having a structure in which the units shown and units based on maleic acids are alternately repeated is obtained.
• the mixing ratio of ⁇ -olefins and maleic acids to obtain the copolymer of the present embodiment varies depending on the composition of the target copolymer, but ⁇ -olefin of 1 to 3 times the number of moles of maleic acids.
• Use of olefin is effective for increasing the reaction rate of maleic acids.
• the method for producing the copolymer of the present embodiment is not particularly limited, and for example, the copolymer can be obtained by radical polymerization.
• the polymerization catalyst used is an azo catalyst such as azobisisobutyronitrile, 1,1-azobiscyclohexane-1-carbonitrile, or an organic peroxide catalyst such as benzoyl peroxide or dicumyl peroxide. preferable.
• the amount of the polymerization catalyst used is required to be in the range of 0.1 to 5 mol%, preferably 0.5 to 3 mol% with respect to maleic acids.
• As a method for adding the polymerization catalyst and the monomer they may be added all at the beginning of the polymerization, but it is desirable to add them sequentially as the polymerization proceeds.
• the molecular weight can be appropriately adjusted mainly depending on the monomer concentration, the amount of catalyst used, and the polymerization temperature.
• the polymerization temperature is preferably 40 ° C.
• the polymerization time is usually preferably about 1 to 24 hours, more preferably 2 to 10 hours.
• the amount of the polymerization solvent used is preferably adjusted so that the concentration of the obtained copolymer is 5 to 40% by weight, more preferably 10 to 30% by weight.
• the copolymer of this embodiment usually has an average molecular weight of 10,000 to 500,000.
• a more preferred average molecular weight is 15,000 to 450,000.
• the average molecular weight of the copolymer of this embodiment is less than 10,000, the crystallinity is high and the adhesive strength between particles may be low.
• it exceeds 500,000 the solubility in water or a solvent becomes small, and it may precipitate easily.
• the average molecular weight of the copolymer of the present embodiment can be measured by, for example, a light scattering method or a viscosity method.
• the copolymer of this embodiment preferably has an intrinsic viscosity in the range of 0.05-2.
• the copolymer of this embodiment is usually obtained in the form of a powder having a grain size of about 16 to 60 mesh.
• the neutralized salt of a copolymer is a neutralized product in which active hydrogen of carbonyl acid generated from maleic acids reacts with a basic substance to form a salt.
• a basic substance containing a monovalent metal and / or ammonia is used as the basic substance from the viewpoint of binding properties. It is preferable.
• the degree of neutralization is not particularly limited, but when used as a binder, considering the reactivity with the electrolytic solution, it is usually 0.3 to 1 mol per carboxylic acid produced from maleic acids. It is preferably in the range of 1 mole, and more preferably neutralized in the range of 0.4 to 1 mole. With such a neutralization degree, it is possible to adjust the pH of the binder composition of the present embodiment to a predetermined range, and further, there is an advantage that the acidity is low and the electrolytic solution decomposition is suppressed.
• the degree of neutralization can be determined by a method such as titration with a base, an infrared spectrum, or an NMR spectrum.
• titration with a base can be performed.
• the specific titration method is not particularly limited, but it can be dissolved in water with little impurities such as ion-exchanged water, and a basic substance such as lithium hydroxide, sodium hydroxide, potassium hydroxide, It can be carried out by neutralization.
• the indicator for the neutralization point is not particularly limited, but an indicator such as phenolphthalein whose pH is indicated by a base can be used.
• the amount of the basic substance containing monovalent metal and / or ammonia is not particularly limited and is appropriately selected depending on the purpose of use and the like, but usually in the maleic acid copolymer.
• the amount is preferably 0.1 to 2 moles per mole of maleic acid units. If it is such usage-amount, it will be possible to adjust pH of the binder composition of this embodiment to the predetermined range.
• the amount of the basic substance containing a monovalent metal is preferably 0.6 to 2.0 mol, more preferably 0.7 to 2. mol per mol of maleic acid unit in the maleic acid copolymer. When the amount is 0 mol, a water-soluble copolymer salt with little alkali residue can be obtained.
• the reaction of the ⁇ -olefin-maleic acid copolymer with a basic substance containing a monovalent metal and / or an amine such as ammonia can be carried out according to a conventional method, but is carried out in the presence of water, and ⁇ - A method for obtaining a neutralized olefin-maleic acid copolymer as an aqueous solution is simple and preferable.
• Examples of basic substances containing monovalent metals that can be used in the present embodiment include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metals such as sodium carbonate and potassium carbonate. Carbonates of alkali metals such as sodium acetate and potassium acetate; phosphates of alkali metals such as trisodium phosphate, and the like.
• ammonia, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferable.
• ammonia or lithium hydroxide as a binder for a lithium ion secondary battery.
• the basic substance containing monovalent metal and / or ammonia may be used alone or in combination of two or more.
• a neutralized product of an ⁇ -olefin-maleic acid copolymer using a basic substance containing an alkali metal hydroxide such as sodium hydroxide as long as the battery performance is not adversely affected. May be prepared.
• the ring-opening rate of the copolymer represents the hydrolysis rate of the site of maleic anhydride that is polymerized with ⁇ -olefins when maleic anhydride is used as the maleic acid.
• a preferable ring opening rate is 60 to 100%, more preferably 70% to 100%, and still more preferably 80 to 100%. If the ring-opening rate is too low, the structural freedom of the copolymer becomes small and the stretchability becomes poor, so that the force for adhering the electrode material particles to be bonded may be small, which is not preferable. Furthermore, there is a possibility that problems such as low affinity for water and poor solubility may occur.
• the ring-opening rate can be determined, for example, by measuring the hydrogen at the ⁇ -position of the maleic acid opened by 1H-NMR with reference to the hydrogen at the ⁇ -position of maleic anhydride.
• the ratio of the carbonyl group derived from the carbonyl group and the ring-opened maleic anhydride can also be determined by IR measurement.
• the neutralized salt of the copolymer means that the active hydrogen of the carbonyl acid generated by the ring opening of maleic anhydride is a basic substance as described above. It forms a salt by forming a salt.
• the degree of neutralization in this case is not particularly limited. However, when used as a thickening stabilizer, considering the reactivity with the electrolytic solution, usually 1 mol of carbonyl acid produced by ring opening. On the other hand, it is preferably in the range of 0.5 to 1 mol, more preferably neutralized in the range of 0.6 to 1 mol. Such a neutralization degree has the advantage of low acidity and suppression of electrolyte decomposition.
• the degree of neutralization of the copolymer when maleic anhydride is used can be measured by the same method as described above.
• the thickening stabilizer of this embodiment contains polyamines and forms a crosslinked structure. By crosslinking, it is possible to impart binding properties.
• the polyamines used in the present embodiment are not limited as long as they are electrochemically stable, but include low molecular weight substances having a molecular weight of less than 300 and / or high molecular weight substances having a molecular weight of 300 or more.
• the low molecular weight polyamines include aliphatic polyamines, aromatic polyamines, and heterocyclic polyamines.
• Preferable specific examples include aliphatic polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and guanidine; aromatic polyamines such as phenylenediamine; and heterocyclic polyamines such as piperazine and N-aminoethylpiperazine. Etc.
• high molecular weight polyamines include amino group-containing polymers, and preferred specific examples thereof include polyethyleneimine, polytetramethyleneimine, polyvinylamine, polyallylamine, dicyandiamide-formalin condensate, dicyandiamide-alkylene ( Polyamine) condensates and the like. These may be used alone or in combination. In view of availability and economy, it is preferable to use polyethyleneimine.
• the molecular weight of these polyamines is not particularly limited, and the average molecular weight is in the range of 50 to 200,000, more preferably in the range of 100 to 180,000, and most preferably in the range of 200 to 100,000. .
• the amount of polyamines added to the thickening stabilizer of the present embodiment is not particularly limited, but is usually 100 parts by weight of an ⁇ -olefin-maleic acid copolymer (solid content). 0.01 parts by weight to 10 parts by weight, and more preferably 0.02 parts by weight to 6 parts by weight.
• An excessive addition amount is not preferable because it forms a complex salt with an ⁇ -olefin-maleic acid copolymer, and the gelation of the strength due to the multi-crosslinking proceeds, and the water is severely restricted and difficult to dry.
• an excessively small addition amount is not preferable because sufficient binding properties cannot be imparted.
• the polyamines can be added simultaneously with the reaction of the ⁇ -olefin-maleic acid copolymer and a basic substance containing a monovalent metal, or the ⁇ -olefin-maleic acid copolymer and It can also be added after reacting a basic substance containing a monovalent metal.
• the temperature for accelerating the crosslinking reaction is not particularly limited, but the crosslinking reaction proceeds rapidly by heating at 20 ° C. or higher, preferably 30 ° C. or higher.
• the time required for convergence of the crosslinking reaction is not limited because it depends on the temperature, but the crosslinking reaction usually converges in about 0.1 hour to 2 months.
• the viscosity of the thickening stabilizer of this embodiment is in the range of 100 to 30000 cP, more preferably in the range of 1000 to 10000 cP.
• the viscosity is 100 cP or less, the coating property is greatly deteriorated due to a significant decrease in the slurry viscosity.
• the viscosity is 30000 cP or more, the wettability with respect to the active material or the conductive auxiliary agent is poor at the time of slurry preparation, and the dispersibility of the active material or conductive auxiliary agent in the slurry is greatly reduced.
• the binder composition usually contains the thickening stabilizer and particulate binder of the present embodiment described above.
• the particulate binder that can be used in the present embodiment is not particularly limited as long as it is particulate and has a binding property to an active material and / or a current collector described later.
• suitable particulate binders include dispersion type binders that are excellent in dispersibility in a dispersion medium.
• Specific dispersion-type binders include, for example, fluoropolymers, diene polymers, vinyl aromatic / conjugated diene random or block copolymers, acrylic polymers, polyimides, polyamides, polyurethane polymers, and the like. A high molecular compound is mentioned.
• the diene polymer is a homopolymer of a conjugated diene, a vinyl aromatic, a random or block copolymer obtained by polymerizing a monomer mixture containing a conjugated diene, or a hydrogenated product thereof.
• Specific examples of the diene polymer include conjugated diene homopolymers such as polybutadiene and polyisoprene; aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copolymer (SBR); Examples thereof include vinyl cyanide / conjugated diene copolymers such as acrylonitrile / butadiene copolymer (NBR); hydrogenated SBR, hydrogenated NBR, and the like.
• conjugated diene homopolymers such as polybutadiene and polyisoprene
• aromatic vinyl / conjugated diene copolymers such as carboxy-modified styrene / butadiene copo
• the acrylic polymer is a homopolymer of acrylic ester or methacrylic ester or a copolymer with a monomer copolymerizable therewith.
• the copolymerizable monomer include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and fumaric acid; two or more carbons such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, and trimethylolpropane triacrylate.
• Carboxylates having carbon double bonds including styrene, chlorostyrene, vinyl toluene, t-butyl styrene, vinyl benzoic acid, methyl vinyl benzoate, vinyl naphthalene, chloromethyl styrene, hydroxymethyl styrene, ⁇ -methyl styrene, Styrenic monomers such as divinylbenzene; Amide monomers such as acrylamide, N-methylolacrylamide, and acrylamide-2-methylpropanesulfonic acid; ⁇ , ⁇ -insoluble such as acrylonitrile and methacrylonitrile Japanese nitrile compounds; olefins such as ethylene and propylene; diene monomers such as butadiene and isoprene; monomers containing halogen atoms such as vinyl chloride and vinylidene chloride; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate Vinyl esters such as methyl
• acrylic polymers, SBR, NBR, and hydrogenated SBR are preferably used, and acrylic polymers, SBR, and hydrogenated SBR are more preferably used.
• “particulate” means polymer fine particles obtained mainly by emulsion polymerization of monomers constituting the above-mentioned polymer, or a polymer emulsified and emulsified after polymerization. Refers to fine particles.
• the particle size of the particulate binder is preferably 0.01 to 0.5 ⁇ m, and more preferably 0.01 to 0.3 ⁇ m. When the particle diameter is 0.01 ⁇ m or less, the increase in slurry viscosity is remarkably caused to deteriorate the coatability. Further, when the particle diameter is 0.5 ⁇ m or more, the binder dispersibility in the electrode is lowered, and the adhesiveness is lowered.
• a protective colloid may be added in order to stabilize the above-mentioned polymer fine particles.
• the protective colloid used in the present invention refers to a hydrocolloid added for the purpose of stabilizing the hydrophobic colloid with respect to the electrolyte. This stabilizing action is thought to be because the hydrocolloid particles enclose the hydrophobic colloid particles and the properties of the hydrocolloid appear as a whole.
• protective colloids examples include polyvinyl alcohol, modified polyvinyl alcohol; water-soluble cellulose derivatives such as methyl cellulose, ethyl cellulose, hydroxymethyl cellulose, and hydroxypropyl cellulose; water-soluble salts of (meth) acrylate-unsaturated carboxylic acid copolymers; styrene -Maleic anhydride copolymer salts, maleated polybutadiene salts, naphthalene sulfonates, polyacrylates and the like. These protective colloids can be used alone or in combination of two or more.
• a water-soluble salt of a (meth) acrylic acid ester-unsaturated carboxylic acid copolymer and / or polyvinyl alcohol as the protective colloid
• (meth) acrylic acid ester- it is very preferable to use a water-soluble salt of an unsaturated carboxylic acid copolymer.
• the nonaqueous electrolyte battery binder composition of the present embodiment is usually a slurry composition for a nonaqueous electrolyte battery electrode (hereinafter simply referred to as “a nonaqueous electrolyte battery electrode slurry”), which further contains an active material and water in addition to the binder composition described above. It is preferably used as a slurry composition). That is, the slurry composition of the present embodiment contains the thickening stabilizer and the particulate binder of the present embodiment described above, an active material, water, and a protective colloid that stabilizes the polymer fine particles as necessary. To do.
• the nonaqueous electrolyte battery electrode is characterized in that a mixed layer containing at least the binder composition and the active material of the present embodiment is bound to a current collector.
• This electrode can be formed by applying the slurry composition described above to a current collector and then removing the solvent by a method such as drying. If necessary, a conductive additive or the like can be added to the mixed layer.
• the amount of the thickening stabilizer used is usually preferably 0.1 to 4 parts by weight, more preferably 0.3 to 3 parts per 100 parts by weight of the active material. Part by weight, more preferably 0.5 to 2 parts by weight. If the amount of the thickening stabilizer is too small, the viscosity of the slurry may be too low and the thickness of the mixed layer may be reduced. Conversely, if the amount of the thickening stabilizer is too large, the discharge capacity may be reduced. .
• the amount of the particulate binder in the slurry composition is usually preferably 0.1 to 4 parts by weight, more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the active material. is there. If the amount of the particulate binder is excessively large, the internal resistance of the battery may be increased. Conversely, if the amount is too small, the binding property is remarkably lowered.
• the solvent in the negative electrode slurry composition of the present embodiment in addition to the above water, for example, alcohols such as methanol, ethanol, propanol and 2-propanol, cyclic ethers such as tetrahydrofuran and 1,4-dioxane, N, Amides such as N-dimethylformamide and N, N-dimethylacetamide, cyclic amides such as N-methylpyrrolidone and N-ethylpyrrolidone, and sulfoxides such as dimethylsulfoxide can also be used. In these, use of water is preferable from a viewpoint of safety.
• the following organic solvent may be used in combination within a range of preferably 20% by weight or less of the total solvent.
• Such an organic solvent preferably has a boiling point at normal pressure of 100 ° C. or higher and 300 ° C. or lower, for example, hydrocarbons such as n-dodecane; alcohols such as 2-ethyl-1-hexanol and 1-nonanol.
• Esters such as ⁇ -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 dimethyl sulfoxide and sulfolane.
• examples of the negative electrode active material (sometimes abbreviated as active material) added to the negative electrode slurry composition include amorphous carbon, graphite, natural graphite, Carbonaceous materials such as mesocarbon microbeads (MCMB) and pitch-based carbon fibers; conductive polymers such as polyacene; composite metal oxides represented by SiOx, SnOx, LiTiOx, other metal oxides, lithium metal, lithium Examples thereof include lithium-based metals such as alloys; metal compounds such as TiS 2 and LiTiS 2 .
• a thickener can be further added to the slurry composition as necessary.
• the thickener that can be added is not particularly limited, and various alcohols, in particular, polyvinyl alcohol and modified products thereof, celluloses, starches, and other polysaccharides can be used.
• the amount of the thickener used as necessary in the slurry composition is preferably about 0.1 to 4 parts by weight, more preferably 0.3 to 3 parts by weight with respect to 100 parts of the negative electrode active material. More preferably, it is 0.5 to 2 parts by weight. If the thickener is too small, the viscosity of the secondary battery negative electrode slurry may be too low and the thickness of the mixed layer may be reduced. Conversely, if the thickener is excessively large, the discharge capacity may be reduced. .
• a conductive support agent mix blended with a slurry composition as needed, metal powder, a conductive polymer, acetylene black etc. are mentioned, for example.
• the amount of the conductive aid used is usually preferably 0.5 to 10 parts by weight, more preferably 1 to 7 parts by weight with respect to 100 parts by weight of the negative electrode active material.
• the current collector used for the nonaqueous electrolyte battery electrode of the present embodiment is not particularly limited as long as it is made of a conductive material.
• a negative electrode for example, iron, copper, aluminum, nickel, stainless steel, titanium Metal materials such as tantalum, gold, and platinum can be used. One of these may be used alone, or two or more of these may be used in combination at any ratio.
• the shape of the current collector is not particularly limited, but usually it is preferably a sheet having a thickness of about 0.001 to 0.5 mm.
• the method for applying the slurry to the current collector is not particularly limited. Examples thereof include a doctor blade method, a dip 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 to be applied is not particularly limited, but the thickness of the mixed layer containing the active material, conductive additive, binder and thickener formed after removing the solvent or dispersion medium by a method such as drying is preferably 0.005 to An amount of 5 mm, more preferably 0.01 to 2 mm is common.
• the method for drying a solvent such as water contained in the slurry composition is not particularly limited, and examples thereof include aeration drying with hot air, hot air, and low-humidity air; vacuum drying; drying with infrared rays, far infrared rays, electron beams, and the like. .
• the drying conditions are preferably adjusted so that the solvent can be removed as soon as possible while the active material layer is cracked by stress concentration or the active material layer does not peel from the current collector.
• the pressing method include a die press and a roll press.
• the present invention also includes a nonaqueous electrolyte battery having the negative electrode.
• the electrode of the present embodiment is a negative electrode
• the nonaqueous electrolyte battery usually includes the negative electrode, the positive electrode, and an electrolytic solution.
• the positive electrode normally used for nonaqueous electrolyte batteries is especially used for a positive electrode without a restriction
• the positive electrode active material 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 , 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.
• the positive electrode active material is made of a conductive additive similar to that of the negative electrode, and a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, and the boiling point at 100 ° C. in water or the above normal pressure.
• a binder such as SBR, NBR, acrylic rubber, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinylidene fluoride, and the boiling point at 100 ° C. in water or the above normal pressure.
• the positive electrode slurry prepared by mixing in a solvent of 300 ° C. or lower can be applied to a positive electrode current collector such as aluminum and the solvent can be dried to obtain a positive electrode.
• an electrolytic solution in which an electrolyte is dissolved in a solvent can be used.
• the electrolyte solution may be liquid or gel as long as it is used for a non-aqueous electrolyte battery such as a normal lithium ion secondary battery, and functions as a battery depending on the type of the negative electrode active material and the positive electrode active material. What is necessary is just to select suitably.
• lithium salt for example, also known lithium salt is any conventionally available, 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 And lower aliphatic lithium carboxylates.
• 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 ⁇ -butyllactone; trimethoxymethane, 1,2-dimethoxyethane, diethyl ether, and 2-ethoxyethane.
• Ethers such as dimethyl sulfoxide; oxolanes 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 Terigres; diglymes; triglymes; sulfolanes; oxazolidinones such as 3-methyl-2-oxazolidinone; sultones such as 1,3-propane sultone, 1,4-butane sultone, naphtha sultone, etc.
• formic acid Organic acid esters such as methyl, methyl acetate, ethyl acetate, buty
• a gel electrolyte a nitrile polymer, an acrylic polymer, a fluorine polymer, an alkylene oxide polymer, or the like can be added as a gelling agent.
• the nonaqueous electrolyte battery of this embodiment Although there is no limitation in particular as a method of manufacturing the nonaqueous electrolyte battery of this embodiment, for example, the following manufacturing method is illustrated. That is, the negative electrode and the positive electrode are overlapped with each other via a separator such as a polypropylene porous membrane, wound or folded according to the shape of the battery, put into a battery container, injected with an electrolyte, and sealed.
• the shape of the battery may be any known coin type, button type, sheet type, cylindrical type, square type, flat type, and the like.
• the nonaqueous electrolyte battery of this embodiment is a battery that achieves both improved adhesion and improved battery characteristics, and is useful for various applications.
• the battery is very useful as a battery used in a portable terminal that is required to be small, thin, light, and have high performance.
• the thickening stabilizer according to one aspect of the present invention is characterized by containing a neutralized salt of an ⁇ -olefin-maleic acid copolymer obtained by copolymerizing an ⁇ -olefin and maleic acid and a polyamine.
• a binder aqueous solution for a nonaqueous electrolyte battery electrode is characterized by containing the above thickening stabilizer and a particulate binder.
• a slurry composition for a nonaqueous electrolyte battery electrode is characterized by including the above binder composition for a nonaqueous electrolyte battery electrode, an active material, and a solvent.
• a nonaqueous electrolyte battery electrode is formed by binding a current collector to a mixed layer containing at least the binder composition for a nonaqueous electrolyte battery electrode and an active material.
• a non-aqueous electrolyte battery according to still another aspect of the present invention is characterized by including the non-aqueous electrolyte battery electrode.
• Example 1 Thickening stabilizer for negative electrode>
• PEI polyethyleneimine
• the slurry for the electrode was prepared by using 2.08 parts by weight of TRD2001 (manufactured by SBR, JSR) as a solid binder and 1008 parts by weight of DMGS (natural graphite, manufactured by BYD) as an active material for the negative electrode. 1.04 parts by weight of the thickening stabilizer as a solid content and 1.04 parts by weight of Super-P (manufactured by Timcal) as a conductive auxiliary agent (conductivity imparting agent) as a solid content are put into a special container. Kneading was performed using a stirrer (ARE-250, manufactured by Shinky Corporation).
• ARE-250 manufactured by Shinky Corporation
• an electrode coating slurry was prepared by adding water at the time of kneading and kneading again.
• the battery coating electrode obtained above was transferred to a glove box (Miwa Seisakusho) under an argon gas atmosphere.
• a metal lithium foil (thickness 0.2 mm, ⁇ 16 mm) was used for the positive electrode.
• a polypropylene system (Celgard # 2400, manufactured by Polypore) is used as a separator, and the electrolyte is ethylene carbonate (EC) of lithium hexafluorophosphate (LiPF 6 ) and vinylene carbonate (EMC) with vinylene carbonate (EMC).
• EC ethylene carbonate
• LiPF 6 lithium hexafluorophosphate
• EMC vinylene carbonate
• EMC vinylene carbonate
• ⁇ Evaluation method 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).
• the coin battery is placed in a constant temperature bath at 25 ° C., and charging is performed with a constant current of 0.1 C (about 0.5 mA / cm 2 ) with respect to the amount of active material until the voltage reaches 0 V with respect to the lithium potential.
• the constant voltage charge of 0V was implemented to the electric current of 0.02 mA.
• the capacity at this time was defined as a charging capacity (mAh / g).
• Example 2 As a negative electrode active material, DMGS (natural graphite, manufactured by BYD) 100 parts by weight TRD2001 (SBR, manufactured by JSR) as a solid binder, 2.08 parts by weight as a solid content, the same thickening as in Example 1 A stabilizer is used as 1.56 parts by weight as a solid content, and Super-P (manufactured by Timcal) as a conductive aid (conductivity imparting agent) is used as a solid content at 1.04 parts by weight in a dedicated container. ARE-250, manufactured by Shinky Corporation).
• an electrode coating slurry was prepared by adding water at the time of kneading and kneading again. Then, the coated electrode was produced by the method similar to the said Example 1, and the toughness test and the peeling strength measurement were performed. Furthermore, the coin battery using this electrode was obtained and the charge / discharge characteristic test was done. These evaluation results are shown in Table 1.
• Example 3 As a negative electrode active material DMGS (natural graphite, BYD) 100 parts by weight, TRD2001 (SBR, manufactured by JSR) as a solid binder, 2.08 parts by weight as a solid content, thickening stability of Example 1 2.08 parts by weight of the agent as a solid content and 1.04 parts by weight of Super-P (manufactured by Timcal) as a conductive auxiliary agent (conductivity imparting agent) as a solid content are put into a special container, and a planetary stirrer (ARE -250, manufactured by Shinky Corporation).
• DMGS natural graphite, BYD
• TRD2001 SBR, manufactured by JSR
• Super-P manufactured by Timcal
• a conductive auxiliary agent conductivity imparting agent
• an electrode coating slurry was prepared by adding water at the time of kneading and kneading again. Then, the coated electrode was produced by the method similar to the said Example 1, and the toughness test and the peeling strength measurement were performed. Furthermore, the coin battery using this electrode was obtained and the charge / discharge characteristic test was done. These evaluation results are shown in Table 1.
• PEI polyethyleneimine
• PEI polyethyleneimine
• Example 6 ⁇ Particulate binder> Hydrogenated block copolymer dissolved in 15 g of polyvinyl alcohol (trade name, manufactured by Kuraray Co., Ltd., Poval 405 (polymerization degree 500, saponification degree 81.5%)) and 300 g of toluene in a 1 L homogenizer equipped with a homomixer. (Septon 2002 (trade name, manufactured by Kuraray Co., Ltd., hydrogenated product of styrene-isoprene-styrene triblock copolymer, styrene content 30%) 150 g and water 500 g were sequentially added, and 10 rpm at room temperature at 15,000 rpm.
• the mixture was stirred for 5 minutes, transferred to a pressure homogenizer, and emulsified, and the resulting dispersion was distilled off toluene and water using a rotary evaporator under reduced pressure and heating (60 ° C.). An aqueous emulsion having an average particle size of 0.3 ⁇ m was obtained.
• the electrode slurry was prepared as follows: 1008 parts by weight of DMGS (natural graphite, manufactured by BYD) as the negative electrode active material, 2.08 parts by weight of the above-mentioned particulate binder as a solid content, the same thickening stability as in Example 1 1.04 parts by weight of the agent as a solid content, and Super-P (manufactured by Timcal) as a conductive auxiliary agent (conductivity imparting agent), 1.04 parts by weight as a solid content, are put into a special container, and a planetary stirrer ( ARE-250, manufactured by Shinky Corporation).
• DMGS natural graphite, manufactured by BYD
• the above-mentioned particulate binder as a solid content
• the same thickening stability as in Example 1 1.04 parts by weight of the agent as a solid content
• Super-P manufactured by Timcal
• a conductive auxiliary agent conductivity imparting agent
• an electrode coating slurry was prepared by adding water at the time of kneading and kneading again. Then, the coated electrode was produced by the method similar to the said Example 1, and the toughness test and the peeling strength measurement were performed. Furthermore, the coin battery using this electrode was obtained and the charge / discharge characteristic test was done. These evaluation results are shown in Table 1.
• DMGS natural graphite, manufactured by BYD
• TRD2001 SBR, manufactured by JSR
• carboxymethylcellulose as a thickening stabilizer
• Super-P manufactured by Timcal
• a conductive auxiliary agent conductivity imparting agent
• an electrode coating slurry was prepared by adding water at the time of kneading and kneading again. Then, the coated electrode was produced by the method similar to the said Example 1, and the toughness test and the peeling strength measurement were performed. Furthermore, the coin battery using this electrode was obtained and the charge / discharge characteristic test was done. These evaluation results are shown in Table 1.
• DMGS natural graphite, manufactured by BYD
• TRD2001 SBR, manufactured by JSR
• hydroxyethyl cellulose as a thickening stabilizer
• Super-P manufactured by Timcal
• a conductive auxiliary agent conductivity imparting agent
• an electrode coating slurry was prepared by adding water at the time of kneading and kneading again. Then, the coated electrode was produced by the method similar to the said Example 1, and the toughness test and the peeling strength measurement were performed. Furthermore, the coin battery using this electrode was obtained and the charge / discharge characteristic test was done. These evaluation results are shown in Table 1.
• Examples 1 to 6 and Comparative Example 1 had lower resistance than Comparative Examples 2 to 3 using a cellulose derivative. This is because Examples 1 to 6 and Comparative Example 1 have a dicarboxylic acid unit in the structure, so that Li ion hopping via a carboxylic acid group occurs and expresses Li ion conductivity. Yes.
• Examples 1 to 6 had higher adhesion than Comparative Examples 1 to 3. This is considered to be due to the cross-linking by polyamine and the excellent binding property of the polymer alone compared to the cellulose derivative. From the above, it was shown that excellent binding property and resistance reduction can be realized by using the thickening stabilizer of the present invention.
• the present invention has wide industrial applicability in the technical field related to non-aqueous electrolyte batteries such as lithium ion secondary batteries.

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