Binder, preparation method therefor and use thereof

Abstract

The present application relates to the technical field of batteries, and specifically relates to a binder, a preparation method therefor and the use thereof. Starting materials for preparing the binder in the present application comprise a first monomer, a second monomer, a third monomer and a fourth monomer; the first monomer comprises a cyclic anhydride compound and / or a non-carboxyl polyamine; the second monomer comprises a small molecule carboxyl polyamine; the third monomer comprises a polymer polyamine and / or a polymer polyol; and the fourth monomer comprises an isocyanate. The binder of the present application improves the rheological properties of electrode slurries formed thereby while maintaining an excellent bonding performance, so as to improve the coating processability of the electrode slurries, and endow further formed electrode sheets with high edge flatness. Thus, the binder improves the quality of the electrode sheets, thereby obtaining batteries having excellent comprehensive properties.

Description

Adhesives, their preparation methods and applications Technical Field

[0001] This application relates to the field of batteries, specifically to a binder, its preparation method, and its application. Background Technology

[0002] Battery slurry is crucial to the preparation and processing of battery electrodes and is a key factor determining the quality of battery electrodes. Battery slurry is a high-viscosity solid-liquid two-phase suspension system obtained by stirring and fully dispersing active materials, binders, conductive agents, and other materials in a solvent. The battery slurry is then coated onto the surface of a current collector to obtain the battery electrode.

[0003] The coating of battery slurry involves different shear rates. During the coating process onto the current collector, the electrode slurry undergoes a high shear rate; at this stage, the shear viscosity should not be too high to avoid uneven coating. After coating onto the current collector, the slurry enters a flow phase under the influence of gravity and surface tension, where the shear rate is lower. To ensure a smooth and uniform coating thickness, the viscosity of the electrode slurry needs to gradually increase during the flow phase and recover to a higher level. Simultaneously, the viscosity recovery time during the flow phase must be neither too long nor too short. If the recovery time is too long, the slurry's fluidity during flow is too high, potentially leading to tailing at the coating edges or a thicker lower edge than the upper edge, resulting in excessive local voltage in the cell. Conversely, if the recovery time is too short, the electrode slurry cannot flow sufficiently, resulting in an uneven coating. This leads to uneven pressure distribution and porosity during the compaction process, ultimately affecting the cell's capacity.

[0004] Therefore, controlling the rheological properties of the electrode slurry is crucial for obtaining high-quality battery electrodes.

[0005] As the most important polymer material in battery slurry, the binder plays a crucial role. Its performance directly affects the rheological properties of the slurry, and consequently, the manufacturing quality and final performance of the battery cell. Therefore, developing a binder that can improve the rheological properties of the battery slurry, thereby enhancing the quality of battery electrode preparation and ultimately obtaining high-performance battery cells, is of paramount importance. Summary of the Invention

[0006] In view of the above problems, this application provides an adhesive, its preparation method and application. The adhesive, while possessing excellent bonding performance, improves the rheological properties of the electrode slurry formed therefrom and enhances the coating and processing performance of the electrode slurry. Furthermore, the resulting electrode sheet has high edge flatness. The adhesive improves the quality of the electrode sheet, and a battery with excellent overall performance can be obtained.

[0007] In a first aspect, this application provides an adhesive, wherein the raw materials for preparing the adhesive include a first monomer, a second monomer, a third monomer, and a fourth monomer;

[0008] The first monomer comprises cyclic anhydride compounds and / or non-carboxyl polyamines;

[0009] The second monomer includes small molecule carboxyl polyamines;

[0010] The third monomer includes polymeric polyamines and / or polymeric polyols;

[0011] The fourth monomer includes isocyanate.

[0012] In the technical solution of this application, a fourth monomer is used as the reactive matrix in the binder. Combined with three different monomers, the resulting binder contains polymer segments with certain intramolecular or intermolecular forces, making it easier for these segments to form a relatively orderly phase, thus obtaining a polymer with certain rheological properties. The electrode slurry formed by the above binder undergoes a high shear rate during the coating stage. Under the action of shear force, the polymer unwinds, and the interaction between polymer chains is small. The shear viscosity of the electrode slurry is within a relatively low range, allowing the slurry to be smoothly coated onto the current collector. After the electrode slurry is coated onto the current collector, it enters a laminar flow stage, and the shear rate rapidly decreases. At this time, the interaction between polymer chains gradually increases, and the orderly chain segments in the polymer partially recover. The viscosity of the electrode slurry gradually increases during the laminar flow process and recovers to a higher level within a suitable time range, resulting in a uniform coating thickness and high edge smoothness. Combined with the excellent bonding properties of the binder, the quality of the electrode sheet is further improved, thereby obtaining a battery with excellent overall performance.

[0013] Specifically, the first monomer, as the base monomer reacting with the fourth monomer, forms the main chain backbone of the binder; the second monomer contains a strongly polar carboxyl group, which enables the polymer to form intra- or inter-chain interactions of a certain strength, regulating the rheological properties of the binder, and improving the adhesive strength of the binder through the interaction between the carboxyl group and the metal current collector; the third monomer can form well-ordered polymer segments that can change from a coiled state to an extended state under high shear; after the external force on the slurry is removed, i.e., when it changes to low shear, the segments can return from the extended state to the coiled state within a certain time, thereby enhancing the rheological properties of the binder. Therefore, the four monomers work together synergistically, enabling the binder to have excellent adhesive properties while improving its rheological properties, which is beneficial for its application in batteries.

[0014] In this application, small molecule carboxyl polyamines refer to carboxyl polyamines that do not contain polymer chain segments, and their molecular weight depends on the chemical formula of the polyamine.

[0015] Preferably, the cyclic anhydride compound includes 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride), 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, and p-phenylene oxide. The dianhydride, 1,2,4-phenyltricarboxylic anhydride, cyclopentanetetracarboxylic anhydride, pyromellitic dianhydride, tetrahydropyromellitic dianhydride, 1,2,4-cyclohexanetricarboxylic anhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, 1,2,3,4-cyclobutanetetracarboxylic anhydride, and bicyclo(2.2.2)oct-7-ene-2,3,5,6-tetracarboxylic anhydride, or any one or a combination of at least two of these.

[0016] Preferably, the cyclic anhydride compound includes any one or a combination of at least two of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, or 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride).

[0017] Preferably, the non-carboxylated polyamine has ≥2 amino groups, such as 3 or 4. Optionally, the non-carboxylated polyamine includes non-carboxylated diamines.

[0018] Preferably, the non-carboxylated polyamines include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 2,7-diamino-9-fluorenone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 1,4-bis(4'-aminophenoxy)benzene, 1,3-bis(4'-aminophenoxy)benzene, 2,2- The first or a combination of at least two of the following: bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 5-amino-2-(4-aminophenyl)benzimidazole, 1,2-bis(2-aminoethoxy)ethane, 3,6,9-trioxaundecane-1,11-diamine, 3,6,9,12-tetraoxatetradecane-1,14-diamine, polyoxyethylene diamine, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane.

[0019] Preferably, the non-carboxylated polyamine comprises one or more combinations of 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4'-aminophenoxy)benzene, 1,3-bis(4'-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)benzene]propane, 1,2-bis(2-aminoethoxy)ethane, 3,6,9-trioxaundecane-1,11-diamine, 3,6,9,12-tetraoxatetradecane-1,14-diamine, polyoxyethylene diamine, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane.

[0020] Preferably, the small molecule carboxyl polyamine has ≥2 amino groups, such as 3 or 4. Optionally, the small molecule carboxyl polyamine includes a small molecule carboxyl diamine.

[0021] Preferably, the small molecule carboxyl polyamine includes lysine, hydroxylysine, arginine, histidine, 2,5-diaminocyclohexanecarboxylic acid, 3,5-diaminocyclohexanecarboxylic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,6-diamino-1,3-phthalic acid, 2,5-diamino-1,4-phthalic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diamino-3,3'-dicarboxyl-5,5'-dimethylbiphenyl, and 4,4'-diamino-3,3'-dicarboxyl 5,5'-Dimethoxybiphenyl, 4,4'-Diaminodiphenylmethane-3-carboxylic acid, 4,4'-Diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-Diaminodiphenylethane-3-carboxylic acid, 4,4'-Diaminodiphenylethane-3,3'-dicarboxylic acid, bis(4-amino-3-carboxyphenyl) ether, bis(4-amino-3,5-dicarboxyphenyl) ether, 1,4-bis(4-amino-3-carboxyphenoxy)benzene, 1,3-bis(4-amino-3-carboxyphenoxy)benzene, bis(4-amino-3-carboxyphenyl) sulfone, bis(4-amino-3,5-dicarboxyphenyl) sulfone, bis[4-(4-amino-3-carboxyphenoxy)phenyl] sulfone, bis[4-(4-amino-3-carboxyphenoxy)phenyl]propane, or a combination of at least two of these.

[0022] Preferably, the number-average molecular weight of the third monomer is ≤3000 g / mol, such as 500 g / mol, 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, etc.

[0023] In the technical solution of this application, the number average molecular weight of the third monomer is within the above range. If the molecular weight of the third monomer is too large, the proportion of well-ordered polymer chain segments increases. Under high shear, the energy barrier required for the polymer molecular chain to change from a coiled state to an extended state gradually increases, which increases the thixotropic time and weakens the rheological properties.

[0024] Preferably, the number of amino groups in the polymeric polyamine is ≥2, such as 3 or 4. Optionally, the polymeric polyamine includes polymeric diamines.

[0025] Preferably, the polymeric polyamine includes any one or a combination of at least two of polyamide polyamine, polyester polyamine, polyesteramide polyamine, or polyacetal polyamine.

[0026] Preferably, the polymeric diamine includes any one or a combination of at least two of polyamide diamine, polyester diamine, polyesteramide diamine, or polyacetal diamine.

[0027] Preferably, the polymer polyol has ≥2 hydroxyl groups, such as 3 or 4. Optionally, the polymer polyol includes polymer diols.

[0028] Preferably, the polymeric polyol includes any one or a combination of at least two of polyamide polyols, polyester polyols, polyesteramide polyols, or polyacetal polyols.

[0029] Preferably, the polymeric diol comprises any one or a combination of at least two of polyamide diol, polyester diol, polyesteramide diol, or polyacetal diol.

[0030] In this application, the polyamide polyamine / alcohol, polyester polyamine / alcohol, and polyesteramide polyamine / alcohol are prepared by reacting saturated / unsaturated polycarboxylic acids with saturated / unsaturated polyols, saturated / unsaturated polyamines, or amino alcohols, or may be prepared by ring-opening polymerization of lactones or lactams.

[0031] In this application, the polyacetal polyamine / alcohol is prepared by reacting formaldehyde with saturated / unsaturated polyols, polyamines, or amino alcohols.

[0032] In this application, the saturated or unsaturated polycarboxylic acids include one or more of succinic acid, glutaric acid, adipic acid, tartaric acid, citric acid, terephthalic acid, phthalic acid, or maleic acid.

[0033] In this application, the saturated or unsaturated polyols include one or more of ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,4-butenediol, 1,5-pentanediol, neopentanediol, hexanediol, diethylene glycol, or trimethylolpropane.

[0034] In this application, the saturated / unsaturated polyamines include one or more of ethylenediamine, 1,4-butanediamine, cyclohexanediamine, 1,6-hexanediamine, decanediamine, diethylenetriamine, triethylenetetramine, or polyethylenepolyamine.

[0035] In this application, the amino alcohols include one or more of ethanolamine, butanolamine, 6-amino-1-hexanol or 4-aminocyclohexanol.

[0036] Preferably, based on a total weight of 100 parts for the first monomer, the second monomer, and the third monomer, the weight of the first monomer is 20 to 40 parts, for example, 25 parts, 30 parts, 35 parts, etc.; and / or;

[0037] The second monomer is present in parts by weight of 10 to 30, for example, 15, 20, or 25 parts; and / or;

[0038] The third monomer is present in parts by weight of 30 to 70, for example, 35, 40, 45, 50, 55, 60, 65, etc.

[0039] In the technical solution of this application embodiment, the total weight of the first monomer, the second monomer, and the third monomer is 100 parts. If the weight of the second monomer is within the above range, and is lower than the weight, the rheological properties will be weakened and the bonding strength will be reduced; if it is higher than the weight, the viscosity of the adhesive will easily increase, or even gel will be formed, affecting the processing of the adhesive.

[0040] In the technical solution of this application embodiment, the total weight of the first monomer, the second monomer, and the third monomer is 100 parts. If the weight of the third monomer is within the above range, it will weaken the rheological properties; if it is higher than the weight, it will easily lead to insufficient binder viscosity, poor electrode slurry suspension ability, and affect the processing of binder.

[0041] In this application, the functionality of the isocyanate is not limited, for example, the functionality is ≥2, such as 3 or 4, and difunctional isocyanates are preferred.

[0042] In this application, the functionality of isocyanate refers to the number of isocyanate groups (-N=C=O) in an isocyanate molecule that can participate in the reaction.

[0043] As an example, the isocyanate includes aliphatic isocyanates and / or aromatic isocyanates;

[0044] Aliphatic isocyanates include any one or a combination of at least two of hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and lysine diisocyanate; aromatic isocyanates include any one or a combination of at least two of 4,4'-diphenylmethane diisocyanate, toluene diisocyanate, phenylenediamine diisocyanate, dimethylbiphenyl diisocyanate, terephthalic diisocyanate, 1,5'-naphthalene diisocyanate, and 3,3'-dichlorobiphenyl-4,4'-diisocyanate.

[0045] In this application, the amount of the fourth monomer added is sufficient to meet the preparation requirements. For example, with the total molar amount of the first monomer, the second monomer, and the third monomer being 100%, the molar amount of the fourth monomer is 100%-120%, such as 112%, 114%, 116%, 118%, etc.

[0046] Preferably, the raw materials for preparing the adhesive also include a neutralizing agent.

[0047] In the technical solution of this application, the raw materials for preparing the binder also include a neutralizing agent. The inventors have discovered that by neutralizing the carboxyl group of the second monomer, the polymer chain can acquire a certain charge, which can further improve the rheological properties and thus further improve the quality of the electrode sheet.

[0048] Preferably, the neutralizing agent comprises any one or a combination of at least two of alkali metal hydroxides, ammonia, or organic amines.

[0049] As an example, the alkali metal hydroxide includes any one or a combination of at least two of lithium hydroxide, sodium hydroxide, and potassium hydroxide; the organic amine includes any one or a combination of at least two of diethylamine, triethylamine, triethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, n-butanolamine, isobutanolamine, tetramethylammonium hydroxide, and tetramethylguanidine.

[0050] In this application, the amount of neutralizing agent added is sufficient to meet the preparation requirements. For example, the weight of the neutralizing agent is not greater than the weight of the second monomer, that is, ≤30 parts, such as 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, etc.

[0051] Preferably, the number average molecular weight of the adhesive is 50,000-200,000 g / mol, such as 60,000 g / mol, 80,000 g / mol, 100,000 g / mol, 120,000 g / mol, 140,000 g / mol, 160,000 g / mol, 180,000 g / mol, etc.

[0052] In the technical solution of this application, the number average molecular weight of the binder is adjusted to be within the above-mentioned range. The reason is that binders within the above-mentioned number average molecular weight range are suitable for use in batteries. If the number average molecular weight of the binder is too low, sedimentation will occur during the subsequent preparation of battery slurry, resulting in poor uniformity of the coated electrode sheets and affecting the performance of the battery. If the number average molecular weight is too high, the prepared battery slurry is prone to local agglomeration, resulting in difficulty in dispersion and affecting the performance of the battery.

[0053] In this application, in order to obtain a suitable number-average molecular weight, chain extenders and / or terminators may be further added for adjustment.

[0054] Preferably, the chain extender has a number average molecular weight of less than 600. For example, the chain extender includes any one or a combination of at least two of the following: ethylene glycol, 1,2-propanediol, 1,4-butanediol, 1,4-butenyldiol, 1,5-pentanediol, neopentanediol, hexanediol, diethylene glycol, hydrazine, ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, butylenediamine, hexamethylenediamine, cyclohexanediamine, piperazine, 2-methylpiperazine, tris(2-aminoethyl)amine, and isophoronediamine.

[0055] Preferably, the number average molecular weight of the terminator is less than 300. For example, the terminator includes any one or a combination of at least two of ethanol, butanol, dodecyl alcohol, phenol, dimethylamine, diethylamine, methyl ethylamine, dipropylamine, N-dodecylmethylamine, and N-methylaniline.

[0056] Secondly, this application provides a method for preparing the adhesive described in the first aspect, the method comprising the following steps:

[0057] The first monomer, the second monomer, the third monomer, and the fourth monomer are mixed and reacted to obtain the adhesive.

[0058] Preferably, the preparation method includes the following steps:

[0059] (1) The first monomer and part of the fourth monomer are mixed and reacted to form a first oligomer solution;

[0060] (2) The first oligomer solution, the second monomer and part of the fourth monomer obtained in step (1) are mixed and reacted to form the second oligomer solution;

[0061] (3) The second oligomer solution obtained in step (2), the third monomer and the remaining fourth monomer are mixed and reacted to obtain the binder.

[0062] In the technical solution of this application, during the preparation of the binder, the first monomer, the second monomer, and the third monomer are added to the reaction system step by step, and the fourth monomer is added to the reaction system in batches, so that each functional monomer can form polymer segments of a certain length, thereby improving the ability of the third monomer to form an ordered phase and the proportion of the ordered phase formed, and improving the rheological properties of the polymer.

[0063] Preferably, in step (1), the first monomer is first dispersed in a solvent.

[0064] Preferably, the solvent comprises any one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, and methyl 5-(dimethylamino)-2-methyl-5-oxo-valerate.

[0065] Preferably, with the total mass of the fourth monomer in steps (1), (2) and (3) being 100%, the mass of the portion of the fourth monomer in step (1) is 10%-40%, for example, 15%, 20%, 25%, 30%, 35%, etc.

[0066] Preferably, in step (1), the temperature of the mixing reaction is 60-100°C, for example 70°C, 80°C, 90°C, etc.; and / or;

[0067] The mixing reaction time is 0.1-10 hours, for example, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, etc.

[0068] Preferably, with the total mass of the fourth monomer in steps (1), (2) and (3) being 100%, the mass of the portion of the fourth monomer in step (2) is 30%-80%, for example, 35%, 40%, 50%, 60%, 70%, etc.

[0069] Preferably, in step (2), the temperature of the mixing reaction is 60-100℃, for example 70℃, 80℃, 90℃, etc.; and / or;

[0070] The mixing reaction time is 0.1-10 hours, for example, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, etc.

[0071] Preferably, in step (3), the temperature of the mixing reaction is 60-100℃, for example 70℃, 80℃, 90℃, etc.; and / or;

[0072] The mixing reaction time is 0.1-10 hours, for example, 1 hour, 2 hours, 4 hours, 6 hours, 8 hours, etc.

[0073] Preferably, in step (3), after the mixing reaction, a neutralizing agent is added.

[0074] As a preferred technical solution, the preparation method includes the following steps:

[0075] (1) Dissolve the first monomer in a solvent, add a portion of the fourth monomer, heat to 60-100℃ and stir to react for 0.1-10h until no bubbles are generated, forming the first oligomer solution;

[0076] (2) Add the second monomer and part of the fourth monomer (30%-50% of the total mass of the fourth monomer) to the first oligomer solution, heat to 60-100℃ and stir to react for 0.1-10h to form the second oligomer solution;

[0077] (3) Add the third monomer and the remaining fourth monomer (20%-40% of the total mass of the fourth monomer) to the second oligomer solution, heat to 60-100℃ and stir to react for 0.1-10h to obtain the binder.

[0078] Thirdly, this application provides an electrode paste, comprising the binder described in the first aspect, or the binder obtained by the preparation method described in the second aspect;

[0079] As an example, the electrode slurry of this application can be a positive electrode slurry or a negative electrode slurry.

[0080] In this application, the electrode paste includes active materials, binders, conductive agents, and solvents.

[0081] This application does not limit the composition of the electrode paste, and any material known in the art can be used.

[0082] As an example, the solid content of the electrode paste can be 50%-80%, such as 55%, 60%, 65%, 70%, 75%, etc.

[0083] As an example, the mass ratio of active material, binder, and conductive agent can be (92-99):(0.5-4):(0.5-4), where 92-99 can be 93, 94, 95, 96, 97, 98, etc.; 0.5-4 can be 1, 1.5, 2, 2.5, 3, 3.5, etc.; the amount of binder and conductive agent added can be the same or different.

[0084] As an example, taking the positive electrode slurry as an example, the active material can be a phosphate material such as lithium iron phosphate; the conductive agent can be a zero-dimensional conductive agent (such as carbon black), a one-dimensional conductive agent (such as carbon nanotubes), a two-dimensional conductive agent (such as graphene), or a three-dimensional conductive agent (such as porous carbon); the solvent can be N-methylpyrrolidone, etc.

[0085] Fourthly, this application provides an electrode sheet comprising the binder described in the first aspect, or the binder obtained by the preparation method described in the second aspect, or the electrode paste described in the third aspect.

[0086] As an example, the electrode sheet of this application can be a positive electrode sheet or a negative electrode sheet.

[0087] In this application, the electrode sheet includes a current collector and an active material layer disposed on at least one surface of the current collector;

[0088] The active material layer includes the binder described in the first aspect, or the binder obtained by the preparation method described in the second aspect, or the electrode paste described in the third aspect.

[0089] This application does not limit the structure and composition of the electrode sheets, and any structure or material known in the art can be used. As an example, the current collector can be a positive current collector, such as aluminum foil, or a negative current collector, such as copper foil.

[0090] Taking the positive electrode as an example, the preparation method of the electrode described in this application includes the following steps:

[0091] Active material layer material, such as active material (e.g., lithium iron phosphate), binder and conductive agent (e.g., carbon black), are dissolved in a solvent (e.g., N-methylpyrrolidone) according to the formula to form a positive electrode slurry. The positive electrode slurry is then coated on the surface of a current collector (e.g., aluminum foil). After drying, pressing and other operations, the positive electrode sheet is obtained.

[0092] Fifthly, this application provides a battery comprising the binder described in the first aspect, or the binder obtained by the preparation method described in the second aspect, or the electrode slurry described in the third aspect, or the electrode sheet described in the fourth aspect.

[0093] Compared with the prior art, this application has at least the following beneficial effects:

[0094] (1) The binder described in this application has excellent bonding performance, improves the rheological properties of the electrode slurry formed by it, and improves the coating and processing performance of the electrode slurry; furthermore, the electrode sheet formed has high edge flatness, and the binder improves the quality of the electrode sheet, so as to obtain a battery with excellent comprehensive performance.

[0095] (2) The electrode slurry formed by the binder described in this application has a shear rate of 1s. -1 The viscosity is in the range of 10290-19220 mPa·s, and the shear rate is 100 s⁻¹. -1The viscosity is in the range of 3840-8250 mPa·s, and the recovery time is in the range of 14-39 s; the peel strength between the active material layer and the current collector of the electrode sheet formed by the binder is 69 N·m. -1 The edge flatness of the electrode sheet is within ±12%.

[0096] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Detailed Implementation

[0097] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0098] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion.

[0099] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0100] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0101] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is also expected that ranges of 60–110 and 80–120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "2-10" indicates that all real numbers between "2-10" have been listed in this article; "2-10" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0102] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0103] The raw material information involved in each embodiment of this application is as follows:

[0104] 3,3',4,4'-Biphenyltetracarboxylic dianhydride: purchased from Tianjin Zhongtai;

[0105] 3,4'-Diaminodiphenyl ether: purchased from Tianjin Zhongtai;

[0106] 1,3-Bis(3-aminopropyl)tetramethyldisiloxane: purchased from Shanghai Maclean;

[0107] Lysine: Purchased from Shanghai Yuanye Biotechnology;

[0108] 4,4'-Diamino-3,3'-dicarboxy-5,5'-dimethylbiphenyl: purchased from Shanghai Maclean;

[0109] Bis(4-amino-3,5-dicarboxyphenyl) ether: purchased from Shanghai Maclean;

[0110] Polyamide diol: purchased from Lubrizol, brand name Aptalon TM 9501, number-average molecular weight 2250 g / mol;

[0111] Polyester diamine: Polyethylene succinate diamine, purchased from Evonik Germany, brand name VERSALINK P1000, number average molecular weight 1200 g / mol;

[0112] Polyether diol: purchased from Jiangsu Haian Petrochemical Plant, model N210, molecular weight 1000g / mol;

[0113] Decanediol: Purchased from Shanghai Maclean's;

[0114] N-Methylpyrrolidone: purchased from Machi Chemical;

[0115] N,N-Dimethylacetamide: purchased from Shanghai Maclean;

[0116] Methyl 5-(dimethylamino)-2-methyl-5-oxo-valerate: purchased from Solvay, Belgium.

[0117] Example 1

[0118] This embodiment provides an adhesive, the raw materials for which the adhesive is prepared include the following components:

[0119] First monomer: 20 parts by weight, 3,3',4,4'-biphenyltetracarboxylic dianhydride;

[0120] Second monomer: 30 parts by weight, lysine;

[0121] Third monomer: 50 parts by weight, polyamide diol, number average molecular weight 2250 g / mol;

[0122] Fourth monomer: 54 parts by weight, toluene diisocyanate;

[0123] Solvent: 120 parts by weight, N-methylpyrrolidone.

[0124] The adhesive is obtained by the following preparation method, which includes the following steps:

[0125] (1) Dissolve 20 parts by weight of 3,3',4,4'-biphenyltetracarboxylic dianhydride in (120 parts by weight) N-methylpyrrolidone, add toluene diisocyanate (13 parts by weight), heat to 80°C and stir to mix for 3 hours until no bubbles are generated, to form the first oligomer solution;

[0126] (2) Add lysine (30 parts by weight) and toluene diisocyanate (36 parts by weight) to the first oligomer solution, heat to 100°C and stir to mix for 4 hours to form the second oligomer solution;

[0127] (3) Add polyamide diol (50 parts by weight) and toluene diisocyanate (5 parts by weight) to the second oligomer solution, heat to 80°C and stir to mix for 2 hours to obtain the adhesive.

[0128] Examples 2-12 and Comparative Examples 1-2

[0129] Except for the parameters in Tables 1-3, the adhesive was obtained according to the preparation method described in Example 1.

[0130] Table 1

[0131] Table 2

[0132] Table 3

[0133] In the table, "—" indicates data that is not involved.

[0134] In Examples 2 and 3, the neutralizing agent was added after the mixing reaction in step (3).

[0135] In Example 11, the neutralizing agent was added after the mixing reaction in step (3), and the rest was the same as in Example 1.

[0136] Example 13

[0137] The difference between this embodiment and Embodiment 1 is that the first monomer, the second monomer, the third monomer, and the fourth monomer are directly mixed, heated to 80°C, stirred and reacted for 9 hours to obtain the binder.

[0138] 1. Testing of electrode paste:

[0139] (1) Preparation of electrode paste

[0140] By weight, 95 parts of lithium iron phosphate (Hunan Yuneng, model Y9), 2.5 parts of conductive carbon black Super P, and 2.5 parts of binder were added to N-methylpyrrolidone at a ratio of 65% of the total solid content, and the mixture was thoroughly mixed using a dual planetary mixer to obtain an electrode slurry containing the prepared binder.

[0141] (2) Viscosity of electrode slurry: The viscosity of the electrode slurry was tested using a rotational rheometer at 25℃. The first-stage shear rate was set to 1 s. -1 The rotation time is 30 seconds, and viscosity data is collected once per second. The viscosity at the 30th second is recorded as η1. The second-stage shear rate is set to 100 seconds. -1The rotation time was 5 seconds, and viscosity data was collected every 0.5 seconds. The viscosity at the 5th second was recorded as η2. The shear rate of the third stage was set to 1 second. -1 The rotation time is 200s, and viscosity data is collected once per second. When the viscosity recovers to 85% of η1, the recovery time is recorded as t.

[0142] The test results are summarized in Table 4.

[0143] Table 4

[0144] Analysis of the data in Table 4 shows that the electrode slurry formed by the binder described in this application has a shear rate of 1 s. -1 The viscosity is in the range of 10290-19220 mPa·s, and the shear rate is 100 s⁻¹. -1 The viscosity is in the range of 3840-8250 mPa·s, and the recovery time is in the range of 14-39 s; the binder described in this application improves the rheological properties of the electrode slurry formed therefrom and improves the coating and processing performance of the electrode slurry.

[0145] Taking Examples 1-3 and Example 11 as examples, within the preferred range, the recovery time of the electrode slurry formed by the binder described in this application is in the range of 18-20 seconds.

[0146] Analysis of Comparative Examples 1-2 and Example 1 shows that the binder of Comparative Example 1 does not contain a small molecule carboxyl polyamine structure, and the binder of Comparative Example 2 does not contain a polymer polyamine or polymer polyol structure. The thixotropic properties of the electrode slurry prepared in this way are significantly reduced, and the viscosity recovery time of the slurry is significantly increased. This proves that the presence of a second monomer and a third monomer in the raw materials for preparing the binder is more conducive to improving the performance of the electrode slurry.

[0147] Analysis of Examples 4 and 1 shows that the thixotropy of the electrode paste prepared in Example 4 is lower than that in Example 1, and the viscosity recovery time of the paste is increased. This proves that among the third monomers of the binder, the polymer polyamine is preferably polyamide polyamine, polyester polyamine, polyesteramide polyamine or polyacetal polyamine; and the polymer polyol is preferably polyamide polyol, polyester polyol, polyesteramide polyol or polyacetal polyol, which is more conducive to improving the performance of the electrode paste.

[0148] Analysis of Examples 5-10 and Example 1 shows that the edge flatness and other properties of the electrode sheets in Examples 5-10 are not as good as those in Example 1. This proves that, based on a total mass of 100 parts of the first monomer, the second monomer, and the third monomer, the first monomer, the second monomer, and the third monomer are more conducive to improving the performance of the electrode paste within the preferred range of this application.

[0149] Analysis of Example 11 and Example 1 shows that the performance of Example 11 is better than that of Example 1, proving that adding a neutralizing agent to the raw materials for preparing the binder is more conducive to improving the performance of the electrode slurry.

[0150] Analysis of Examples 12 and 1 shows that the performance of Example 12 is inferior to that of Example 1, proving that the preferred polymer polyols are polyamide polyols, polyester polyols, polyesteramide polyols, or polyacetal polyols, which are more conducive to improving the performance of the electrode paste. Similarly, the preferred polymer diamines are polyamide diamines, polyester diamines, polyesteramide diamines, or polyacetal diamines, which are more conducive to improving the performance of the electrode paste.

[0151] Analysis of Example 13 and Example 1 shows that the performance of Example 13 is not as good as that of Example 1, proving that adding the various raw materials of the binder in batches or in sequence is more conducive to improving the performance of the electrode slurry.

[0152] 2. Testing of electrode plates

[0153] (1) Preparation of electrode sheets

[0154] The electrode paste was filtered through a 100-mesh sieve and then coated onto a 10μm thick aluminum foil using an extrusion coater at a speed of 40m / min to form an active material layer. After drying in a 110℃ forced-air drying tunnel, it was then subjected to a 1×10⁻⁶ folding process. 4 Electrode sheets are obtained by rolling under a unit length load of N / m.

[0155] (2) Edge flatness of electrode sheet: The edge thickness of the electrode sheet is measured as h1; the average thickness of the electrode sheet is measured as h2; the edge flatness is calculated as (h1-h2) / h2×100%.

[0156] (3) Peel strength of active material layer in electrode sheet: The electrode sheet prepared above is cut into strips of 100mm×20mm. The current collector side is fixed to a steel plate with a thickness of 1mm with double-sided tape. Transparent tape is pasted on the coating layer side. Under the condition of 25℃, a 180° tensile peel test is carried out using a universal electronic testing machine at a peel speed of 100mm / min. The peel strength is recorded.

[0157] The test results are summarized in Table 5.

[0158] Table 5

[0159] Analysis of the data in Table 5 shows that the peel strength between the active material layer and the current collector of the electrode sheet formed by the binder described in this application is 69 N·m. -1The edge flatness of the electrode sheet is within ±12%. The binder described in this application, based on its excellent bonding performance, improves the rheological properties of the electrode slurry formed therefrom and enhances the coating and processing performance of the electrode slurry. Furthermore, the electrode sheet formed has high edge flatness. The binder improves the quality of the electrode sheet, resulting in a battery with excellent overall performance.

[0160] Taking Examples 1-3 and Example 11 as examples, within the preferred range, the electrode paste formed by the binder described in this application has an edge smoothness within the range of ±3%.

[0161] Analysis of Comparative Examples 1-2 and Example 1 shows that the performance of Comparative Examples 1-2 is not as good as that of Example 1, proving that the presence of a second monomer and a third monomer in the raw materials for preparing the binder is more conducive to improving the performance of the electrode sheet.

[0162] Analysis of Example 4, Comparative Example 3 and Example 1 shows that the performance of Example 4 and Comparative Example 3 is not as good as that of Example 1. This proves that in the third monomer of the binder, the polymer polyamine is preferably polyamide polyamine, polyester polyamine, polyesteramide polyamine or polyacetal polyamine; the polymer polyol is preferably polyamide polyol, polyester polyol, polyesteramide polyol or polyacetal polyol, which is more conducive to improving the performance of the electrode sheet.

[0163] Analysis of Examples 5-10 and Example 1 shows that the performance of Examples 5-10 is not as good as that of Example 1. This proves that, based on a total mass of 100 parts of the first monomer, the second monomer, and the third monomer, the first monomer, the second monomer, and the third monomer are more conducive to improving the performance of the electrode sheet within the preferred range of this application.

[0164] Analysis of Example 11 and Example 1 shows that the performance of Example 11 is better than that of Example 1, proving that adding a neutralizing agent to the raw materials for preparing the binder is more conducive to improving the performance of the electrode sheet.

[0165] Analysis of Examples 12 and 1 shows that the performance of Example 12 is inferior to that of Example 1, proving that the preferred polymer polyols are polyamide polyols, polyester polyols, polyesteramide polyols, or polyacetal polyols, which are more conducive to improving the performance of the electrode sheet. Similarly, the preferred polymer diamines are polyamide diamines, polyester diamines, polyesteramide diamines, or polyacetal diamines, which are more conducive to improving the performance of the electrode sheet.

[0166] Analysis of Example 13 and Example 1 shows that the performance of Example 13 is not as good as that of Example 1, proving that adding the various raw materials of the binder in batches or in sequence is more conducive to improving the performance of the electrode sheet.

[0167] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An adhesive, characterized in that, The raw materials for preparing the adhesive include a first monomer, a second monomer, a third monomer, and a fourth monomer; The first monomer comprises cyclic anhydride compounds and / or non-carboxyl polyamines; The second monomer includes small molecule carboxyl polyamines; The third monomer includes polymeric polyamines and / or polymeric polyols; The fourth monomer includes isocyanate.

2. The adhesive according to claim 1, characterized in that, The cyclic anhydride compounds include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride), 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, and p-phenyldiphenyl... Any one or a combination of at least two of the following: trimellitate dianhydride, 1,2,4-phenyltricarboxylic anhydride, cyclopentanetetracarboxylic anhydride, pyromellitic dianhydride, tetrahydropyromellitic dianhydride, 1,2,4-cyclohexanetricarboxylic anhydride, 1,4,5,8-naphthalenetetracarboxylic anhydride, 1,2,3,4-cyclobutanetetracarboxylic anhydride, and bicyclo(2.2.2)oct-7-ene-2,3,5,6-tetracarboxylic anhydride; Preferably, the cyclic anhydride compound includes any one or a combination of at least two of 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3',4'-diphenyl ether tetracarboxylic dianhydride, or 4,4'-(4,4'-isopropyldiphenoxy)bis(phthalic anhydride); Preferably, the non-carboxylated polyamine has ≥2 amino groups; optionally, the non-carboxylated polyamine includes non-carboxylated diamines. Preferably, the non-carboxylated polyamines include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 2,7-diamino-9-fluorenone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, 1,4-bis(4'-aminophenoxy)benzene, 1,3-bis(4'-aminophenoxy)benzene, 2,2- The first or a combination of at least two of the following: bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis(trifluoromethyl)diaminobiphenyl, 5-amino-2-(4-aminophenyl)benzimidazole, 1,2-bis(2-aminoethoxy)ethane, 3,6,9-trioxaundecane-1,11-diamine, 3,6,9,12-tetraoxatetradecane-1,14-diamine, polyoxyethylene diamine, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane; Preferably, the non-carboxylated polyamine comprises one or more combinations of 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4'-aminophenoxy)benzene, 1,3-bis(4'-aminophenoxy)benzene, 2,2-bis[4-(4-aminophenoxy)benzene]propane, 1,2-bis(2-aminoethoxy)ethane, 3,6,9-trioxaundecane-1,11-diamine, 3,6,9,12-tetraoxatetradecane-1,14-diamine, polyoxyethylene diamine, and 1,3-bis(3-aminopropyl)tetramethyldisiloxane.

3. The adhesive according to claim 1 or 2, characterized in that, The small molecule carboxyl polyamine has ≥2 amino groups, and optionally, the small molecule carboxyl polyamine includes a small molecule carboxyl diamine; Preferably, the small molecule carboxyl polyamine includes lysine, hydroxylysine, arginine, histidine, 2,5-diaminocyclohexanecarboxylic acid, 3,5-diaminocyclohexanecarboxylic acid, 2,4-diaminobenzoic acid, 2,5-diaminobenzoic acid, 3,5-diaminobenzoic acid, 4,6-diamino-1,3-phthalic acid, 2,5-diamino-1,4-phthalic acid, 4,4'-diaminobiphenyl-3-carboxylic acid, 4,4'-diaminobiphenyl-3,3'-dicarboxylic acid, 4,4'-diaminobiphenyl-2,2'-dicarboxylic acid, 3,3'-diaminobiphenyl-4,4'-dicarboxylic acid, 3,3'-diaminobiphenyl-2,4'-dicarboxylic acid, 4,4'-diamino-3,3'-dicarboxyl-5,5'-dimethylbiphenyl, and 4,4'-diamino-3,3'-dicarboxyl 5,5'-Dimethoxybiphenyl, 4,4'-Diaminodiphenylmethane-3-carboxylic acid, 4,4'-Diaminodiphenylmethane-3,3'-dicarboxylic acid, 4,4'-Diaminodiphenylethane-3-carboxylic acid, 4,4'-Diaminodiphenylethane-3,3'-dicarboxylic acid, bis(4-amino-3-carboxyphenyl) ether, bis(4-amino-3,5-dicarboxyphenyl) ether, 1,4-bis(4-amino-3-carboxyphenoxy)benzene, 1,3-bis(4-amino-3-carboxyphenoxy)benzene, bis(4-amino-3-carboxyphenyl) sulfone, bis(4-amino-3,5-dicarboxyphenyl) sulfone, bis[4-(4-amino-3-carboxyphenoxy)phenyl] sulfone, bis[4-(4-amino-3-carboxyphenoxy)phenyl]propane, or a combination of at least two of these.

4. The adhesive according to any one of claims 1-3, characterized in that, The number-average molecular weight of the third monomer is ≤3000 g / mol; Preferably, the polymeric polyamine contains ≥2 amino groups; optionally, the polymeric polyamine includes a polymeric diamine. Preferably, the polymeric polyamine includes any one or a combination of at least two of polyamide polyamine, polyester polyamine, polyesteramide polyamine, or polyacetal polyamine; Preferably, the polymeric diamine includes any one or a combination of at least two of polyamide diamine, polyester diamine, polyesteramide diamine, or polyacetal diamine; Preferably, the polymeric polyol contains ≥2 hydroxyl groups; optionally, the polymeric polyol includes polymeric diols. Preferably, the polymeric polyol includes any one or a combination of at least two of polyamide polyol, polyester polyol, polyesteramide polyol, or polyacetal polyol; Preferably, the polymeric diol comprises any one or a combination of at least two of polyamide diol, polyester diol, polyesteramide diol, or polyacetal diol.

5. The adhesive according to any one of claims 1-4, characterized in that, With a total weight of 100 parts for the first monomer, the second monomer, and the third monomer, the first monomer comprises 20 to 40 parts by weight; and / or; The second monomer is present in parts by weight of 10 to 30; and / or; The third monomer is present in parts by weight of 30 to 70 parts; Preferably, the raw materials for preparing the adhesive further include a neutralizing agent; Preferably, the neutralizing agent comprises any one or a combination of at least two of alkali metal hydroxides, ammonia, or organic amines; Preferably, the number average molecular weight of the adhesive is 50,000-200,000 g / mol.

6. A method for preparing the adhesive according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: The first monomer, the second monomer, the third monomer, and the fourth monomer are mixed and reacted to obtain the adhesive.

7. The preparation method according to claim 6, characterized in that, The preparation method includes the following steps: (1) The first monomer and part of the fourth monomer are mixed and reacted to form a first oligomer solution; (2) The first oligomer solution, the second monomer and part of the fourth monomer obtained in step (1) are mixed and reacted to form the second oligomer solution; (3) The second oligomer solution obtained in step (2), the third monomer and the remaining fourth monomer are mixed and reacted to obtain the binder; Preferably, in step (1), the first monomer is first dispersed in a solvent; Preferably, the solvent comprises any one or a combination of at least two of N-methylpyrrolidone, N,N-dimethylacetamide, 3-methoxy-N,N-dimethylpropionamide, and methyl 5-(dimethylamino)-2-methyl-5-oxo-valerate. Preferably, with the total mass of the fourth monomer in steps (1), (2) and (3) being 100%, the mass of the portion of the fourth monomer in step (1) is 10%-40%; Preferably, with the total mass of the fourth monomer in steps (1), (2) and (3) being 100%, the mass of the portion of the fourth monomer in step (2) is 30%-80%; Preferably, in step (3), after the mixing reaction, a neutralizing agent is added.

8. An electrode paste, characterized in that, Includes the adhesive according to any one of claims 1-5, or the adhesive obtained by the preparation method according to claim 6 or 7.

9. An electrode sheet, characterized in that, The electrode sheet comprises the binder according to any one of claims 1-5, or the binder obtained by the preparation method according to claim 6 or 7, or the electrode slurry according to claim 8.

10. A battery, characterized in that, The battery comprises the binder according to any one of claims 1-5, or the binder obtained by the preparation method according to claim 6 or 7, or the electrode slurry according to claim 8, or the electrode sheet according to claim 9.

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