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CN-122025642-A - Battery monomer and preparation method thereof, battery device, energy storage device and electricity utilization device

CN122025642ACN 122025642 ACN122025642 ACN 122025642ACN-122025642-A

Abstract

The application relates to the field of energy storage battery cores, and provides a battery monomer, a preparation method thereof, a battery device, an energy storage device and an electricity utilization device. In the battery monomer, the positive electrode active layer comprises a binder and a cross-linking agent, the positive electrode active layer comprises a polymer network, the polymer network comprises the binder and the cross-linking agent, the binder comprises modified polyvinylidene fluoride, a carboxyl group is grafted on a main chain of the modified polyvinylidene fluoride, and the cross-linking agent is provided with an epoxy group. The battery cell can at least inhibit the migration of the binder in the positive electrode plate, improve the peeling strength of the positive electrode plate after use, reduce the internal resistance of the positive electrode plate and facilitate the improvement of the service performance of the battery cell.

Inventors

  • Luan Xiangsen
  • SUN GUOYU
  • YANG ZIXIANG
  • ZHANG LUHUA

Assignees

  • 浙江晶科储能有限公司

Dates

Publication Date
20260512
Application Date
20260409

Claims (14)

  1. 1. The battery cell is characterized by comprising a positive electrode plate, wherein the positive electrode plate comprises a positive electrode current collector, at least one surface of the positive electrode current collector is provided with a positive electrode active layer, the positive electrode active layer comprises a binder and a cross-linking agent, and the positive electrode active layer comprises a polymer network, and the polymer network comprises the binder and the cross-linking agent; The adhesive comprises modified polyvinylidene fluoride, and carboxyl is grafted on the main chain of the modified polyvinylidene fluoride; The crosslinking agent includes at least one of tetraglycidyl-4, 4' -diaminodiphenylmethane, triglycidyl para-aminophenol, tetraphenylethane tetraglycidyl ether, polyethylene glycol diglycidyl ether, or vinylcyclohexene dioxide.
  2. 2. The battery cell according to claim 1, wherein the modified polyvinylidene fluoride has a carboxyl functionality of 0.15mmol/g to 0.35mmol/g.
  3. 3. The battery cell according to claim 1 or 2, wherein the mass content of the binder is 2% to 3% and the mass content of the crosslinking agent is 0.2% to 0.5% based on the mass of the positive electrode active layer.
  4. 4. The battery cell according to claim 1 or2, wherein the modified polyvinylidene fluoride has a number average molecular weight of 50000 to 150000.
  5. 5. The battery cell according to claim 1, wherein the positive electrode active layer further comprises 96% -97% of a positive electrode active material and 0.5% -0.8% of a conductive agent based on the mass of the positive electrode active layer.
  6. 6. The preparation method of the battery monomer is characterized by comprising the following steps of: Coating positive electrode slurry on at least one surface of a positive electrode current collector, and drying to enable the positive electrode slurry to be solidified to form a positive electrode active layer; The positive electrode slurry comprises a binder and a cross-linking agent, wherein the binder comprises modified polyvinylidene fluoride, carboxyl groups are grafted on the main chain of the modified polyvinylidene fluoride, and the cross-linking agent comprises at least one of tetraglycidyl-4, 4' -diaminodiphenylmethane, triglycidyl para-aminophenol, tetraphenylethane tetraglycidyl ether, polyethylene glycol diglycidyl ether or vinylcyclohexene dioxide; During curing, the binder and the cross-linking agent cross-link and form a polymer network.
  7. 7. The method for producing a battery cell according to claim 6, wherein the temperature at the time of drying is 100 ℃ to 140 ℃.
  8. 8. The method for preparing a battery cell according to claim 6, wherein the modified polyvinylidene fluoride is prepared by the steps of: And mixing polyvinylidene fluoride, anhydride and an initiator, and then reacting for 2-10 min at 180-200 ℃ to enable the anhydride to be grafted with the main chain of the polyvinylidene fluoride, wherein the anhydride comprises at least one of maleic anhydride, phthalic acid or succinic anhydride.
  9. 9. The method for producing a battery cell according to claim 8, wherein the initiator comprises at least one of dicumyl peroxide or dibenzoyl peroxide.
  10. 10. The method for preparing a battery cell according to claim 8, wherein the drying treatment is performed after the grafting is completed, and the temperature at the time of the drying treatment is 80 ℃ to 90 ℃.
  11. 11. The method for producing a battery cell according to claim 10, wherein an extraction process is further performed after the drying process is performed.
  12. 12. A battery device, characterized by comprising the battery cell according to any one of claims 1-5 or the battery cell manufactured by the manufacturing method of the battery cell according to any one of claims 6-11, wherein the battery device comprises one or more of a battery module, a battery pack and an energy storage battery.
  13. 13. An energy storage device comprising the battery device of claim 12 for storing electrical energy.
  14. 14. An electrical device comprising a battery device according to claim 12 for providing electrical energy.

Description

Battery monomer and preparation method thereof, battery device, energy storage device and electricity utilization device Technical Field The application relates to the field of energy storage battery cells, in particular to a battery cell, a preparation method thereof, a battery device, an energy storage device and an electricity utilization device. Background Battery cells such as lithium ion batteries are widely used in daily life. An adhesive is generally present in the positive electrode tab of the battery cell to enhance the adhesion in the positive electrode active layer of the positive electrode tab and between the positive electrode active layer and the positive electrode current collector. However, the adhesive in the positive electrode plate can migrate, so that the peeling strength of the positive electrode plate is reduced, the internal resistance is increased, and the service performance of the battery monomer is affected. Disclosure of Invention The application provides a battery monomer, a preparation method thereof, a battery device, an energy storage device and an electric device, which can at least inhibit migration of an adhesive in a positive pole piece, improve peel strength of the positive pole piece after use, reduce internal resistance of the positive pole piece and facilitate improvement of service performance of the battery monomer. The first aspect of the application provides a battery monomer, which comprises a positive electrode plate, wherein the positive electrode plate comprises a positive electrode current collector, at least one surface of the positive electrode current collector is provided with a positive electrode active layer, the positive electrode active layer comprises a binder and a cross-linking agent, the positive electrode active layer comprises a polymer network, the polymer network comprises the binder and the cross-linking agent, the binder comprises modified polyvinylidene fluoride, carboxyl groups are grafted on a main chain of the modified polyvinylidene fluoride, and the cross-linking agent comprises at least one of tetraglycidyl-4, 4' -diaminodiphenylmethane, triglycidyl para-aminophenol, tetraphenylethane tetraglycidyl ether, polyethylene glycol diglycidyl ether or vinylcyclohexene dioxide. The second aspect of the application also provides a preparation method of the battery monomer, wherein the preparation step of the positive electrode plate in the battery monomer comprises the steps of coating positive electrode slurry on at least one surface of a positive electrode current collector, and drying to enable the positive electrode slurry to be solidified to form a positive electrode active layer, wherein the positive electrode slurry comprises a binder and a cross-linking agent, the binder comprises modified polyvinylidene fluoride, carboxyl groups are grafted on a main chain of the modified polyvinylidene fluoride, the cross-linking agent comprises at least one of tetraglycidyl-4, 4' -diaminodiphenyl methane, triglycidyl para-aminophenol, tetraphenyl ethane tetraglycidyl ether, polyethylene glycol diglycidyl ether or vinylcyclohexene dioxide, and the cross-linking agent form a polymer network in the solidification process. A third aspect of the present application provides a battery device comprising the battery cell of the first aspect, or the battery cell as produced by the method of producing a battery cell of the second aspect, the battery device comprising one or more of a battery module, a battery pack, and an energy storage battery. A fourth aspect of the application provides an energy storage device comprising the battery device of the third aspect, the battery device being for storing electrical energy. A fifth aspect of the application provides an electrical consumer comprising the battery device of the third aspect, the battery device being arranged to provide electrical energy. The technical scheme provided by the application has at least the following advantages: in the battery monomer, the carboxyl grafted on the modified polyvinylidene fluoride main chain has good reactivity, the epoxy group contained in the cross-linking agent also has good reactivity, ring-opening addition reaction can be carried out between the carboxyl and the epoxy group to form a polymer network, the structure can reduce the mobility of the modified polyvinylidene fluoride, improve the cohesive force inside the positive electrode active layer, the adhesive force between the positive electrode active layer and the positive electrode current collector and the uniformity of the positive electrode active layer, thereby improving the electrochemical performance of the positive electrode plate, reducing the layering risk of the positive electrode plate, and improving the service performance of the battery monomer. Drawings One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, which are not to be construe