Aqueous polymer composition for dispersing carbon-based materials

Abstract

The invention relates to a process for the preparation of a rechargeable battery component, wherein a composition comprising a) water, b) an electrically conductive carbon-based material and c) a polymer comprising polymerized monomer repeat units of i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate, and iii) an olefinically unsaturated monomer having 1 or 2 carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form, is used for the preparation of the component.

Description

[0001] This invention relates to a method for preparing a rechargeable battery assembly, the use of a composition comprising water and a polymer as a dispersant for a conductive carbon-based material for a rechargeable battery, and a rechargeable battery.

[0002] International patent publication WO 2022 / 248318 A1 relates to coating and / or paint compositions containing specific copolymer dispersants. These compositions comprise materials that can be polymerized by at least one acrylic monomer, at least one hydrophobic non-acrylic monomer, and at least one C1-C... 12 A copolymer obtained from alkoxy polyethylene glycol (meth)acrylate.

[0003] US Patent Publication US 2006 / 0074002 A1 describes partially esterified copolymers of monoolefinic unsaturated dicarboxylic anhydrides, vinyl aromatic compounds, and other non-olefinic unsaturated monomers containing heteroatoms. These polymers are used as additives in detergents and cleaning agents.

[0004] Japanese Patent Application JP 2007 261911 A relates to a slurry composition for producing ceramics, and more specifically to a slurry composition for producing ceramic electronic components such as ceramic capacitors, varistors, thermistors, electrolyte filters, and sensors. The slurry contains a dispersant, which is a copolymer of polyoxyalkylene ethers, maleic anhydride, and styrene.

[0005] There is a persistent need for improved methods for preparing rechargeable battery components. Existing methods for preparing rechargeable battery components typically use non-aqueous liquid compositions based on organic solvents. Given the fire risks, industrial hygiene risks, and adverse health effects associated with organic solvents, their use in such methods is undesirable. Therefore, the use of aqueous compositions in such methods is desirable. Compositions used to prepare rechargeable battery components typically contain particles of conductive carbon-based material in a dispersed form. It is important that these particles are well dispersed and remain well dispersed. Poor particle dispersion typically manifests itself as a high viscosity of the dispersion. High-viscosity compositions are undesirable because they are difficult to process and require additional diluents to achieve the desired viscosity. Furthermore, excessively high viscosity of the dispersion indicates insufficient and uneven dispersion of the conductive carbon-based material particles. In addition to the aforementioned processing performance issues, insufficient and uneven dispersion reduces the quality of battery components prepared from such compositions. The present invention addresses the above-mentioned problems.

[0006] This invention provides a method for preparing a rechargeable battery assembly, wherein a composition comprising the following components is used to prepare the assembly:

[0007] a) water,

[0008] b) Conductive carbon-based materials, and

[0009] c) A polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

[0010] The method of the present invention mitigates or eliminates the above-mentioned disadvantages.

[0011] The method of the present invention relates to a method for preparing a rechargeable battery assembly. In a preferred embodiment of the invention, a lithium-ion rechargeable battery is described as a specific example. The lithium-ion rechargeable battery has a structure in which the anode and cathode are immersed in an electrolyte. In the lithium-ion rechargeable battery, a separator may be provided between the cathode and the anode. Examples of such separators include nonwoven fabrics, cloths, and microporous membranes, each primarily containing polyolefins such as polyethylene and polypropylene, combinations thereof.

[0012] In a preferred embodiment of the invention, known organic electrolytes, inorganic solid electrolytes, and polymer solid electrolytes can be used as the electrolyte for forming a lithium-ion rechargeable battery.

[0013] In the method of this invention, a composition is used to prepare a rechargeable battery assembly. The composition comprises:

[0014] a) water,

[0015] b) Conductive carbon-based materials, and

[0016] c) A polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

[0017] The composition contains water. Water is present as a liquid diluent to give the composition a liquid or paste-like state. In a typical embodiment, water is present in the composition in an amount of 95-30% by weight, calculated based on the total weight of the composition. In a preferred embodiment, water is present in the composition in an amount of 90-40% by weight. When the water content is very high, the viscosity of the composition may become too low and the evaporation of water after application of the composition may take too long. When the water content is very low, the viscosity of the composition may become too high to allow the composition to be shaped as required for a rechargeable battery assembly.

[0018] Water is typically the primary liquid diluent in this composition. In some embodiments, the composition may additionally contain one or more organic liquid diluents, also known as organic solvents. If such organic solvents are present, water-miscible organic solvents are preferred. Considering solvent emissions and industrial hygiene, it is preferable that the composition contains a small amount of organic solvent. This means a composition appropriately containing organic solvent in an amount of 0.0-15.0% by weight, preferably 0.0-10.0% by weight, more preferably 0.0-7.0% by weight, of volatile organic solvent based on the total weight of the composition.

[0019] The optional organic solvent may also include more than one type of organic solvent, such as a mixture of two or more types of solvents. Examples of suitable solvents include ester solvents, such as methyl acetate, ethyl acetate, butyl butyrate, γ-butyrolactone, and ε-caprolactone; or carbonate solvents, such as dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), and propylene carbonate (PC); alcohol solvents, such as ethanol and isopropanol; and nitriles, such as R-CN (where R is linear, branched, or cyclic C2-C). 20 Hydrocarbon groups (which may include double bonds, aromatic rings, or ether bonds); amides such as dimethylformamide; dioxolane such as 1,3-dioxolane; or sulfolane can be used as organic solvents. Examples of other suitable solvents include aprotic dipolar solvents such as dimethyl sulfoxide, dimethylformamide, or N-methylpyrrolidone, or other solvents containing amide groups.

[0020] In a further preferred embodiment, polymer c) is dissolved in water or an aqueous liquid phase of the composition. When the polymer is dissolved in water or an aqueous liquid phase of the composition, the polymer and water form a continuous, homogeneous single phase, as opposed to an aqueous dispersion or emulsion in which the polymer exists as a discontinuous phase in the form of solid or liquid particles.

[0021] The composition further comprises a conductive carbon-based material. The carbon-based material is composed of 90-100% by weight of carbon. For use in battery module manufacturing, a conductive carbon-based material is selected. The conductive carbon-based material exists in the composition in the form of solid particles. In a preferred embodiment, the conductive carbon-based material includes at least one of carbon nanotubes, carbon black, graphene, fullerene, and carbon fibers. Carbon nanotubes are particularly preferred.

[0022] Carbon nanotubes (CNTs) are tubes made of carbon with diameters in the nanometer range. They are one of the allotropes of carbon. Single-walled carbon nanotubes have diameters of approximately 0.5–2.0 nanometers. They can be idealized as fragments taken from two-dimensional graphene sheets wound to form hollow cylinders.

[0023] Multi-walled carbon nanotubes are composed of nested single-walled carbon nanotubes in a nested tube-within-a-tube structure. Double-walled and triple-walled carbon nanotubes are special cases of multi-walled carbon nanotubes.

[0024] The composition further comprises a polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) a polymerized monomer repeating unit of an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

[0025] The polymer in the composition is used as a dispersant for the conductive carbon-based material.

[0026] The polymer contains repeating units of polymerized vinyl aromatic monomers.

[0027] Vinyl aromatic monomers are monomers having polymerizable olefinic unsaturated groups and aromatic groups. Preferably, the polymerizable olefinic unsaturated groups and aromatic groups are conjugated. In some embodiments, the vinyl aromatic monomer is a hydrocarbon monomer, such as styrene and various isomers of methylstyrene, such as 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, and β-methylstyrene. Similar isomers of dimethylstyrene and trimethylstyrene may also be used.

[0028] In some embodiments, the vinyl aromatic monomer comprises one or more of an ether group and a hydroxyl group. Examples of such monomers include p-coumarol, coniferol, sinigrin, 4-vinylphenol, 4-vinylguaiacol, and 4-vinyleugenol.

[0029] Styrene is commercially available and provides good performance for polymers as dispersants. Therefore, styrene is a preferred vinyl aromatic monomer.

[0030] Preferably, the vinyl aromatic monomer does not contain a carboxylic acid group.

[0031] The polymer contains i) polymerized monomer repeating units of vinyl aromatic monomers in an amount of 50-90 mol%, preferably 55-85 mol%, where mol% is calculated based on the total moles of polymerized monomers. A very good balance of polymeric properties is achieved within these ranges, particularly as an effective dispersant for conductive carbon-based materials and also exhibiting sufficient solubility in water.

[0032] In addition, the polymer contains repeating units of polymerized polyether acrylate or polyether methacrylate monomers.

[0033] Such repeating units are appropriately provided by monomers of the following formula (I):

[0034]

[0035] in

[0036] R 1 Indicates H or CH3,

[0037] R a Indicates linear or branched alkylene groups having 2-6 carbon atoms.

[0038] R b The symbol represents an aralkyl group, preferably benzyl; or an alkyl group having 1-8 carbon atoms, preferably methyl, ethyl, propyl, or butyl; or H, and

[0039] n represents an integer from 1 to 150, preferably from 1 to 50, and more preferably from 1 to 25.

[0040] And in the presence of at least two different types of residues R a In the case of n [R] a O] unit, [R a O] n The chain can have random, block, or gradient structures.

[0041] Examples of suitable monomers include polyether monohydric alcohols, such as ethers—polyethylene glycol, polypropylene glycol, polybutanediol, or (meth)acrylates of mixed polyalkylene glycols having 4-80 carbon atoms and having statistical, block, or gradient distributions of different monomers along the chain, such as diethylene glycol methyl ether (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methyltriethylene glycol (meth)acrylate, ethyltriethylene glycol (meth)acrylate, butyldiethylene glycol (meth)acrylate, polypropylene glycol methyl ether (meth)acrylate, and polyethylene glycol alkyl ether (meth)acrylate, wherein the alkyl group represents a straight-chain or branched alkyl residue having 1-22, preferably 1-15, more preferably 1-13, even more preferably 1-10, and most preferably 1-7 carbon atoms.

[0042] In a preferred embodiment, the polyether acrylate or polyether methacrylate comprises at least one polymerized unit of ethylene oxide and propylene oxide. The presence of polymerized units of ethylene oxide optionally combined with polymerized units of propylene oxide improves the water solubility of the polymer.

[0043] In a preferred embodiment, the polyether acrylate or polyether methacrylate contains 3-50, more preferably 4-35, non-cyclic ether groups.

[0044] Suitable polyethers are polyether acrylates or polyether methacrylates, with the polyethers being capped with hydroxyl or hydrocarbon groups.

[0045] In a typical embodiment, 20-80% by weight, preferably 30-70% by weight, of the repeating units of polymer c) are based on the above-mentioned polyether acrylate or polyether methacrylate.

[0046] In another embodiment, the repeating units of polymer c) of 5-45 mol%, preferably 10-35 mol%, are based on polyether acrylate or polyether methacrylate, wherein the mol% is calculated based on the total number of moles of polymerized monomers.

[0047] In addition, the polymer contains a polymerized olefinic unsaturated monomer repeating unit having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

[0048] Examples of suitable olefinically unsaturated monomers having a carboxylic acid group are acrylic acid and methacrylic acid. Other examples include 2-phenylacrylic acid and 3-phenylacrylic acid, as well as 2- or 3-alkylacrylic acid, wherein the alkyl group has 2 to 6 carbon atoms.

[0049] Unsaturated olefinic monomers having two carboxylic acid groups include maleic acid, fumaric acid, itaconic acid, citraconic acid, and mesocarboxylic acid. Instead of the aforementioned dicarboxylic acids, the corresponding cyclic anhydrides can also be used in this polymerization method, followed by hydrolysis of the anhydride groups.

[0050] Considering the commercial availability and good dispersant properties of the resulting polymer, it is preferred to use an olefinic unsaturated monomer having one or two carboxylic acid groups, including at least one of maleic acid, acrylic acid, and methacrylic acid.

[0051] Preferably, the olefinic unsaturated monomer having one or two carboxylic acid groups does not contain aromatic groups.

[0052] At least some of the carboxylic acid groups in the polymer exist in the form of salts.

[0053] In a typical embodiment, the salt is an alkali metal salt or an ammonium salt. In a preferred embodiment, the salt is a sodium salt or a salt of ammonia or an amine having 1-18 carbon atoms. The amine can be a primary, secondary, or tertiary amine.

[0054] In a typical embodiment, polymer c) contains polymerized monomer repeating units of an olefinic unsaturated monomer having one or two carboxylic acid groups in an amount of 5-45 mol%, preferably 10-35 mol%, wherein the mol% is calculated based on the total number of moles of polymerized monomers.

[0055] Polymer c) has carboxylic acid groups due to the presence of repeating units of the polymerized monomer of an olefinically unsaturated monomer having one or two carboxylic acid groups. The amount of carboxylic acid groups can be determined by titration. The acid value is the amount of KOH (mg) required to neutralize 1g of the substance. The acid value is suitably determined according to DIN EN ISO 2114 by a neutralization reaction with a 0.1N KOH ethanol solution. In a preferred embodiment, the polymer has an acid value in the range of 30-180 mg KOH / g, more preferably 50-160 mg KOH / g.

[0056] The acid value refers to the total number of acid groups in the polymer, including neutralized acid groups present in salt form.

[0057] Suitable polymer c) has a number-average molecular weight in the range of 1,500-30,000 g / mol, preferably in the range of 2,000-20,000 g / mol or 2,000-15,000 g / mol.

[0058] The weight-average molecular weight of the polymer can be appropriately determined by gel permeation chromatography (GPC) using polystyrene as a calibration standard and THF as the eluent.

[0059] In a preferred embodiment, polymer c) comprises i) 50-90 mol% of vinyl aromatic monomers, ii) 5-45 mol% of polyether acrylate or polyether methacrylate and iii) 5-45 mol% of polymerized monomer repeating units of olefinic unsaturated monomers having one or two carboxylic acid groups, wherein mol% is calculated based on the total number of moles of polymerized monomers.

[0060] In another preferred embodiment, polymer c) comprises i) 50-80 mol% of vinyl aromatic monomers, ii) 10-40 mol% of polyether acrylate or polyether methacrylate and iii) 10-40 mol% of polymerized monomer repeating units of olefinic unsaturated monomers having one or two carboxylic acid groups, wherein mol% is calculated based on the total number of moles of polymerized monomers.

[0061] In polymer c), the repeating units of polymerized monomers i), ii), and iii) can exist in a random order or as blocks of repeating units of one type of monomer. Preferably, the repeating units exist in a random order.

[0062] In some embodiments, the polymer is composed of repeating units of the polymerized monomers i), ii), and iii) as described above. However, the polymer may also include small amounts of other monomers. These other monomers are typically present in an amount of 0-10 mol% repeating units. Optional other monomers include (meth)acrylates of straight-chain, branched, or alicyclic alcohols having 1-22, preferably 1-12, more preferably 1-8, and most preferably 1-6 carbon atoms. Other optional monomers include olefinically unsaturated polymerizable compounds having amide groups, such as acrylamide and methacrylamide and their N-substituted derivatives.

[0063] For use in the method of preparing a rechargeable battery assembly, the composition appropriately further comprises an organic polymer binder different from polymer c).

[0064] This adhesive improves adhesion between the component and any surface on which the composition is applied, such as current collectors or any other components of an electrochemical device. Examples of adhesives include known adhesives such as fluoropolymers like polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, and polytetrafluoroethylene; rubber-based adhesives such as styrene-butadiene rubber (SBR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), ethylene-propylene-diene monomer rubber (EPDM), sulfonated EPDM, and fluororubber; polyethylene; polypropylene; polyvinyl alcohol; polyvinylpyrrolidone, polyacrylonitrile; carboxymethyl cellulose (CMC); starch; hydroxypropyl cellulose; regenerated cellulose; and polyacrylate-based adhesives such as polyacrylic acid (PAA). If desired, the adhesive can be used in the form of an aqueous dispersion.

[0065] The appropriate amount of adhesive is 1.0-50.0 parts by weight per 100 parts by weight of the non-volatile material of the composition, and is particularly preferably about 1.0-20.0 parts by weight, more preferably 1.0-10.0 parts by weight.

[0066] The organic polymer adhesive is suitably present in the form of an aqueous solution, an aqueous dispersion, or an aqueous emulsion.

[0067] As described above, the present invention relates to a method for manufacturing a rechargeable battery assembly.

[0068] In a preferred embodiment, the rechargeable battery assembly is an anode or a cathode.

[0069] If the component is a cathode, the composition appropriately also includes a cathode active material. Transition metal oxides containing lithium or lithium metal phosphates such as LiFePO4 are typically used as cathode active materials, and preferably mainly contain lithium and at least one oxide of a transition metal element selected from Ti, V, Cr, Mn, Fe, Co, Ni, Mo and W.

[0070] In a particularly preferred embodiment, the rechargeable battery assembly is the anode. In some embodiments, the anode is a silicon-containing anode.

[0071] Electrodes can be formed by molding the aforementioned electrode composition. For this purpose, the composition can be in paste form. Electrodes are obtained, for example, by applying the paste to a current collector, followed by drying and pressure molding.

[0072] Examples of current collectors include foils and meshes made of aluminum, nickel, copper, stainless steel, etc. The coating thickness of the paste is typically 40-200 μm. There are no particular limitations on the paste application method, and examples of application methods include those involving application with a doctor blade or rod applicator, followed by roll molding. Examples of pressure molding include roll molding, compression molding, etc.

[0073] In another preferred embodiment of the method of the present invention, the rechargeable battery assembly is a current collector for the anode or cathode, preferably the current collector for the anode. The current collector for the anode is preferably made of copper. The current collector for the cathode is preferably made of aluminum.

[0074] In this embodiment, the composition is applied as a primer coating to the current collector. The primer is suitably applied to the current collector at a thickness of 1-10 micrometers. This primer layer serves as an intermediate layer between the current collector and the electrode active material.

[0075] In a typical embodiment, the primer layer comprises a conductive carbon-based material comprising i) a polymer of polymerized monomer repeating units of a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate, and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form, and a polymeric adhesive different from, or composed of, the aforementioned polymer. Examples of suitable adhesives are carboxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, and combinations thereof.

[0076] The primer layer reduces the resistance between the current collector and the electrode active material, improves the adhesion of the electrode active material to the current collector, and provides corrosion protection for the current collector.

[0077] As described above, the polymer present in this composition is well-suited for dispersing conductive carbon-based materials in aqueous compositions. Therefore, the present invention also relates to the use of a composition comprising water and a polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups (wherein at least a portion of the carboxylic acid groups are present in salt form) as a dispersant for conductive carbon-based materials for rechargeable batteries.

[0078] In another embodiment, the present invention relates to a rechargeable battery comprising a conductive carbon-based material and a polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

[0079] Example

[0080] Raw materials and abbreviations

[0081] α-MSD: α-methylstyrene dimer

[0082] MPEG500MA: A methacrylate of polyethylene glycol monomethyl ether with a number average molecular weight of 500 g / mol.

[0083] MPEG750MA: A methacrylate of polyethylene glycol monomethyl ether with a number average molecular weight of 750 g / mol.

[0084] MPEG1000MA: A methacrylate of polyethylene glycol monomethyl ether with a number average molecular weight of 1000 g / mol.

[0085] C18-PEG1105MA: A methacrylate of polyethylene glycol monostearin ether with a number average molecular weight of 1105 g / mol.

[0086] AIVN: 2,2'-Azobisisovalerate

[0087] Trigonox ® 21S Peroxy-2-ethylhexanoate tert-butyl

[0088] Comparative Example 1: Aqueous solution of polymer with neutralized carboxylic acid groups

[0089] Comparative Example 2: Polyvinylpyrrolidone

[0090] Comparative Example 3: Cationic polyether-modified styrene / maleic anhydride copolymer

[0091] Comparative Example 4: Polyether-modified epoxyamine addition products

[0092] Comparative Example 5: Aqueous solution of polyether-modified styrene / maleic anhydride copolymer

[0093] Comparative Example 6: Carboxymethyl cellulose

[0094] Polymer preparation

[0095] Example 1

[0096] Add 24.38 g of methoxypropyl acetate and 1.57 g (0.0066 mol) of α-MSD to a four-necked flask and heat to 130°C. Mix 12.00 g (0.1152 mol) of styrene, 14.40 g (0.0288 mol) of MPEG500MA, and 6.00 g of methoxypropyl acetate and feed over 2 hours. Simultaneously begin feeding a mixture of 2.82 g (0.0288 mol) of maleic anhydride, 14.78 g of methoxypropyl acetate, and 0.87 g (0.0053 mol) of AIVN over 2.5 hours. When the feeding is complete, maintain the mixture at 130°C for another hour. Then, feed a mixture of 3 g of methoxypropyl acetate and 0.44 g (0.027 mol) of AIVN over 0.5 hours. Maintain the mixture at 130°C for another hour. The polymer has an acid value of 100 mg KOH / g. Mn(GPC): 2815 g / mol.

[0097] The polymer solution was cooled to 40°C and 132 g of water was added. Then, 8.85 g (0.0473 mol KOH) of a 30% potassium hydroxide aqueous solution was added. The mixture was stirred for 0.5 hours and then heated to 100°C. Methoxypropyl acetate and water were evaporated off, and the removed amount was replenished with water until no more methoxypropyl acetate could be evaporated off. The final non-volatile content of the polymer aqueous solution was 20% by weight.

[0098] Example 2

[0099] The polymer of Example 2 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0100] 24.38g of methoxypropyl acetate and

[0101] 1.57g (0.0066mol) α-MSD

[0102] 12g (0.1152mol) styrene

[0103] 14.4g (0.0288mol) MPEG500MA

[0104] 6g of methoxypropyl acetate.

[0105] 2.82g (0.0288mol) maleic anhydride

[0106] 14.78g methoxypropyl acetate

[0107] 0.87g (0.0053mol) AIVN

[0108] 3g methoxypropyl acetate

[0109] 0.44g (0.027mol) AIVN

[0110] Acid value 100 mg KOH / g, Mn 3279 g / mol

[0111] 130.87g water

[0112] 5.74g (0.0473mol) of 33% sodium hydroxide aqueous solution.

[0113] The final non-volatile content of the polymer aqueous solution is 20% by weight.

[0114] Example 3

[0115] The polymer of Example 3 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0116] 16.32g methoxypropyl acetate

[0117] 1.35g (0.0057mol) α-MSD

[0118] 10.32g (0.0991mol) styrene

[0119] 24.77g (0.0248mol) MPEG1000MA

[0120] 20.64g methoxypropyl acetate

[0121] 2.43g (0.0248mol) maleic anhydride,

[0122] 12.72g methoxypropyl acetate

[0123] 0.75g (0.0046mol) AIVN

[0124] 10.32g methoxypropyl acetate

[0125] 0.38g (0.0023mol) AIVN

[0126] Acid value: 62.5 mg KOH / g. Mn: 4082 g / mol

[0127] 57g water

[0128] 9.27g (0.0496mol) of 30% potassium hydroxide solution

[0129] The final non-volatile content of the polymer aqueous solution is 40% by weight.

[0130] Example 4

[0131] The polymer in Example 4 was prepared similarly to that in Example 1. The raw materials and properties are summarized below.

[0132] 12.22g methoxypropyl acetate

[0133] 1.28g (0.0054mol) α-MSD

[0134] 9.78g (0.0939mol) of styrene,

[0135] 17.61g (0.0235mol) MPEG750MA

[0136] 7.82g methoxypropyl acetate

[0137] 2.3g (0.0235mol) maleic anhydride,

[0138] 24.1g methoxypropyl acetate

[0139] 0.71g (0.0043mol) AIVN

[0140] 3.91g methoxypropyl acetate

[0141] 0.36g (0.0022mol) AIVN

[0142] Acid value: 72.5 mg KOH / g. Mn: 2853 g / mol

[0143] 138.5g water

[0144] 8.77g (0.0469mol) 30% potassium hydroxide

[0145] The final non-volatile content of the polymer aqueous solution is 20% by weight.

[0146] Example 5

[0147] The polymer in Example 5 was prepared similarly to that in Example 1. The raw materials and properties are summarized below.

[0148] 51.11g methoxypropyl acetate

[0149] 3.49g (0.0148mol) α-MSD

[0150] 20.0g (0.192mol) styrene,

[0151] 64.01g (0.128mol) MPEG500MA

[0152] 10g methoxypropyl acetate

[0153] 6.27g (0.064mol) maleic anhydride,

[0154] 73.92g methoxypropyl acetate

[0155] 1.94g (0.0118mol) AIVN

[0156] 10g methoxypropyl acetate

[0157] 0.97g (0.0059mol) AIVN

[0158] Acid value: 66.5 mg KOH / g. Mn: 3187 g / mol

[0159] 398.7g water

[0160] 23.9g (0.128mol) 30% potassium hydroxide

[0161] The final non-volatile content of the polymer aqueous solution is 20% by weight.

[0162] Example 6

[0163] The polymer of Example 6 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0164] 39.7g methoxypropyl acetate

[0165] 40.0g (0.384mol) styrene,

[0166] 48.1g (0.096mol) MPEG500MA

[0167] 9.41g (0.096mol) maleic anhydride

[0168] 19.48g methoxypropyl acetate

[0169] 77.93g methoxypropyl acetate

[0170] 2.92g (0.0177mol) AIVN

[0171] 5.59g methoxypropyl acetate

[0172] 1.46g (0.0089mol) AIVN

[0173] Acid value: 100 mg KOH / g. Mn: 4326 g / mol

[0174] 425.15g water

[0175] 35.88g (0.192mol) of 30% potassium hydroxide solution

[0176] The final non-volatile content of the polymer aqueous solution is 20% by weight.

[0177] Comparative Example 7

[0178] The polymer of Comparative Example 7 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0179] 44.39g methoxypropyl acetate

[0180] 3.84g (0.0112mol) α-MSD

[0181] 33.0g (0.3169mol) of styrene,

[0182] 105.62g(0.1056mol) MPEG1000MA,

[0183] 34.32g methoxypropyl acetate

[0184] 1.14g (0.007mol) AIVN

[0185] 2.86g methoxypropyl acetate

[0186] 0.29g (0.0017mol) AIVN

[0187] 7.04g methoxypropyl acetate

[0188] 0.7g (0.0043mol) AIVN

[0189] Acid value: 0 mg KOH / g. Mn: 4598 g / mol

[0190] 220.0g water

[0191] The final non-volatile content of the polymer aqueous solution is 30% by weight.

[0192] Example 7

[0193] The polymer of Example 7 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0194] 48.32g methoxypropyl acetate

[0195] 6.55g (0.0277mol) α-MSD

[0196] 50g (0.48mol) of styrene,

[0197] 67.69g (0.12mol) MPEG500MA

[0198] 24.38g of methoxypropyl acetate,

[0199] 10.33g (0.12mol) methacrylic acid

[0200] 2.44g (0.0148mol) AIVN

[0201] 12.1g methoxypropyl acetate

[0202] 1.2g (0.0073mol) AIVN

[0203] Acid value: 55 mg KOH / g. Mn: 5049 g / mol

[0204] 323.9g water

[0205] 14.45g (0.12mol) of 33% sodium hydroxide solution

[0206] The final non-volatile content of the polymer aqueous solution is 30% by weight.

[0207] Example 8

[0208] The polymer of Example 8 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0209] 24.38g methoxypropyl acetate

[0210] 1.57g (0.0066mol) α-MSD

[0211] 12g (0.1152mol) styrene

[0212] 14.4g (0.0288mol) MPEG500MA

[0213] 6g methoxypropyl acetate

[0214] 2.82g (0.0288mol) maleic anhydride,

[0215] 14.78g methoxypropyl acetate

[0216] 0.87g (0.0053mol) AIVN

[0217] 3g methoxypropyl acetate

[0218] 0.44g (0.027mol) AIVN

[0219] Acid value: 100 mg KOH / g. Mn: 3279 g / mol

[0220] 130.87g water

[0221] 2.87g (0.0237mol) 33% Sodium Hydroxide

[0222] The final non-volatile content of the polymer aqueous solution is 20% by weight.

[0223] Example 9

[0224] The polymer of Example 9 was prepared similarly to that of Example 1. The raw materials and properties are summarized below.

[0225] 51.46g methoxypropyl acetate

[0226] 4.58g (0.0194mol) α-MSD

[0227] 30.0g (0.3899mol) styrene,

[0228] 40.61g(0.0720mol) MPEG500MA,

[0229] 10.38g (0.1440mol) acrylic acid

[0230] 1.71g (0.0077mol) Trigonox 21S

[0231] 1.71g methoxypropyl acetate

[0232] 1.71g (0.0077mol) Trigonox 21S

[0233] 1.71g methoxypropyl acetate

[0234] Acid value: 102 mg KOH / g. Mn: 4583 g / mol

[0235] 48.88g water

[0236] 17.96g (0.1483mol) of 33% sodium hydroxide solution

[0237] The final non-volatile content of the polymer aqueous solution is 20% by weight.

[0238] Preparation of compositions containing conductive carbon-based materials

[0239] 0.4 g of the appropriate polymer, 18.3 g of softened water, 0.8 g of carbon nanotubes (CnanoFT7320), 0.1 g of defoamer (BYK-024), and 60 g of zirconia beads (1.0 mm) were added to a 100 ml glass bottle. Dispersion was performed for 720 minutes using a LAU DAS 200 disperser at cooling setting 3, followed by sieving to remove the zirconia beads. The slurry was finally evaluated by measuring its viscosity at 23°C using a conical geometry (25 1°) on an Anton Paar MCR 102. The results are summarized in the table below.

[0240]

[0241] The following conclusion can be drawn: the composition of the present invention has a significantly lower viscosity than the composition of Comparative Example 1. The composition of Comparative Example 1 has too high a viscosity for use in the preparation of rechargeable battery components.

[0242] Add 0.4g of the appropriate polymer, 18.7g of softened water, 0.8g of carbon nanotubes (CnanoFT7320), 0.1g of defoamer (BYK-024), and 60g of zirconia beads (1.0mm) to a 100ml glass bottle. Disperse the mixture using a LAU DAS 200 disperser at cooling setting 3 for 720 minutes, then sieve out the zirconia beads. Finally, evaluate the slurry by measuring its viscosity at 23°C on an Anton Paar MCR 102 with a conical geometry (25 1°).

[0243]

[0244] The following conclusion can be drawn: the compositions of the present invention have a significantly lower viscosity than the comparative compositions. The comparative compositions have too high a viscosity for use in the preparation of rechargeable battery components.

[0245] Add 0.3g of the appropriate polymer, 19.0g of softened water, 0.6g of carbon nanotubes (Nanoyl NC7000), 0.1g of defoamer (BYK-024), and 60g of zirconia beads (1.0mm) to a 100ml glass bottle. Disperse the mixture using a LAU DAS 200 disperser at cooling setting 3 for 720 minutes, then sieve out the zirconia beads. Finally, evaluate the slurry by measuring its viscosity at 23°C on an Anton Paar MCR 102 with a conical geometry (25 1°).

[0246]

[0247] The following conclusion can be drawn: the compositions of the present invention have a significantly lower viscosity than the comparative compositions. The comparative compositions have too high a viscosity for use in the preparation of rechargeable battery components.

[0248] Add 0.3g of the appropriate polymer, 16.6g of softened water, 3.0g of conductive carbon black (IMERYS C-NERGY SUPER C 65), 0.1g of defoamer (BYK-024), and 60g of zirconia beads (1.0mm) to a 100ml glass bottle. Disperse the mixture for 300 minutes using a LAU DAS200 disperser at cooling setting 3, then sieve out the zirconia beads. Finally, evaluate the slurry by measuring its viscosity at 23°C using a conical geometry (25 1°) on an Anton Paar MCR 102.

[0249]

[0250] Add 0.3g of the appropriate polymer, 19.0g of softened water, 0.6g of carbon nanotubes (Nanoyl NC7000), 0.1g of defoamer (BYK-024), and 60g of zirconia beads (1.0mm) to a 100ml glass bottle. Disperse the mixture using a LAU DAS 200 disperser at cooling setting 3 for 720 minutes, then sieve out the zirconia beads. Finally, evaluate the slurry by measuring its viscosity at 23°C on an Anton Paar MCR 102 with a conical geometry (25 1°).

[0251]

[0252] The following conclusion can be drawn: the compositions of the present invention have a significantly lower viscosity than the comparative compositions. The comparative compositions have too high a viscosity for use in the preparation of rechargeable battery components.

Claims

1. A method for preparing a rechargeable battery assembly, wherein a composition comprising the following components is used to prepare the assembly: a) water, b) Conductive carbon-based materials, and c) A polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

2. The method of claim 1, wherein the polymer is dissolved in water.

3. The method according to claim 1 or 2, wherein the vinyl aromatic monomer is styrene.

4. The method according to any one of the preceding claims, wherein the polyether acrylate or polyether methacrylate comprises at least one polymerized unit of ethylene oxide and propylene oxide.

5. The method according to any one of the preceding claims, wherein the polyether acrylate or polyether methacrylate comprises 3-50 noncyclic ether groups.

6. The method according to any one of the preceding claims, wherein the polyether of the polyether acrylate or polyether methacrylate is end-capped with a hydroxyl or hydrocarbon group.

7. The method according to any one of the preceding claims, wherein the olefinic unsaturated monomer having one or two carboxylic acid groups comprises at least one of maleic acid, acrylic acid, and methacrylic acid.

8. The method according to any one of the preceding claims, wherein the polymer c) has a number-average molecular weight in the range of 1500-30000 g / mol.

9. The method according to any one of the preceding claims, wherein 20-80% by weight of the repeating unit of polymer c) is based on the polyether acrylate or polyether methacrylate.

10. The method according to any one of the preceding claims, wherein the polymer has an acid value in the range of 30-180 mg KOH / g.

11. The method according to any one of the preceding claims, wherein the polymer c) comprises i) 50-90 mol% of a vinyl aromatic monomer, ii) 5-45 mol% of a polyether acrylate or polyether methacrylate and iii) 5-45 mol% of a polymerized monomer repeating unit of an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein mol% is calculated based on the total number of moles of polymerized monomers.

12. The method according to any one of the preceding claims, wherein the conductive carbon-based material comprises at least one of carbon nanotubes, carbon black, graphene, fullerene, and carbon fiber.

13. The method according to any one of the preceding claims, wherein the composition further comprises an organic polymer adhesive different from polymer c).

14. The method according to any one of the preceding claims, wherein the rechargeable battery assembly is an anode or a cathode.

15. Use of a composition as a dispersant for a conductive carbon-based material for rechargeable batteries, said composition comprising water and a polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

16. A rechargeable battery comprising a conductive carbon-based material and a polymer comprising i) a vinyl aromatic monomer, ii) a polyether acrylate or polyether methacrylate and iii) an olefinic unsaturated monomer having one or two carboxylic acid groups, wherein at least a portion of the carboxylic acid groups are present in salt form.

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