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CN-122000554-A - Battery cell, battery device and electricity utilization device

CN122000554ACN 122000554 ACN122000554 ACN 122000554ACN-122000554-A

Abstract

The application provides a battery monomer, a battery device and an electricity utilization device, and belongs to the technical field of batteries. The battery monomer comprises a positive electrode plate, a positive electrode film layer of the positive electrode plate comprises a positive electrode additive, the positive electrode additive comprises a first polymer and a second polymer, the first polymer comprises a fluorine-containing olefin polymer, the second polymer comprises an anchoring group G and a flexible chain segment, the anchoring group G contains at least one of carboxyl, sulfonic acid group, phosphate ester group, amide group and ester group, and the main chain of the flexible chain segment contains at least one of carbon-carbon single bond, carbon-oxygen single bond, ether bond, ester bond and amide bond. The application can improve the stability of the small-particle-size positive electrode active material slurry through the coordination of the first polymer and the second polymer.

Inventors

  • MIAO YUANYUAN
  • XU CHONG
  • PEI TONG
  • HUANG RULONG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (12)

  1. 1. The battery monomer comprises a positive electrode plate, wherein the positive electrode plate comprises a positive electrode film layer, and the battery monomer is characterized in that the positive electrode film layer comprises a positive electrode additive, and the positive electrode additive comprises a first polymer and a second polymer; The first class of polymers includes fluoroolefin polymers; The second polymer comprises an anchoring group G and a flexible chain segment, wherein the anchoring group G comprises at least one of carboxyl, sulfonic acid group, phosphate ester group, amide group and ester group, and the main chain of the flexible chain segment comprises at least one of carbon-carbon single bond, carbon-oxygen single bond, ether bond, ester bond and amide bond.
  2. 2. The battery cell of claim 1, wherein the soft segment further comprises at least one branch comprising at least one of a carbon chain, a benzene ring, an anhydride, a polyether, a cyclic ether.
  3. 3. The battery cell of claim 1 or 2, wherein the second polymer has a structural formula as shown in formula (I):
  4. 4. a battery cell according to any one of claims 1 to 3, wherein the anchoring group G is a group of formula (II) or formula (III): formula (II) Formula (III); Wherein, C n is alkyl carbon chain, and R' comprises at least one of hydrogen atom, C 1 -C 12 alkyl carbon chain, C 1 -C 12 alkyl alcohol and C 1 -C 12 alkyl hydroxylamine.
  5. 5. A battery cell according to any one of claims 1 to 3, wherein the anchoring group G is a group of formula (IV) or formula (V): Wherein, R' comprises at least one of hydrogen atom, C 1 -C 12 alkyl carbon chain, C 1 -C 12 alkyl alcohol and C 1 -C 12 alkyl hydroxylamine.
  6. 6. A battery cell according to any one of claims 1 to 3, wherein the anchoring group G is a group of formula (VI) or formula (VII): Wherein, R 3 and R 5 are both C 1 -C 12 alkyl hydroxylamine, and R 4 comprises at least one of hydrogen atom, C 1 -C 12 alkyl carbon chain and C 1 -C 12 alkyl alcohol.
  7. 7. The battery cell of any one of claims 1 to 6, wherein the polymerized monomer of the first polymer comprises at least one of the compounds of formula (VIII), formula (IX): R 1 、R 2 comprises at least one of hydrogen atom, C 1 -C 12 alkyl carbon chain, C 1 -C 12 alkyl benzene ring carbon chain, polyether chain segment and polyoxyethylene ether-polyoxypropylene ether copolymer chain segment.
  8. 8. The battery cell according to any one of claims 1 to 7, wherein the positive electrode additive is present in the positive electrode film layer in an amount of 0.01% to 3% by mass.
  9. 9. The battery cell of claim 8, wherein the first polymer comprises 0.5% to 1.1% by mass of the positive electrode layer and/or, The mass ratio of the second polymer in the positive electrode film layer is 0.16% -0.36%.
  10. 10. The battery cell of any one of claims 1 to 9, wherein the positive electrode film layer has a coating thickness of 100 μιη to 120 μιη.
  11. 11. A battery device comprising the battery cell according to any one of claims 1 to 10.
  12. 12. An electrical device comprising the battery device of claim 11.

Description

Battery cell, battery device and electricity utilization device Technical Field The application relates to the technical field of batteries, in particular to a battery cell, a battery device and an electricity utilization device. Background Based on the requirement of long endurance, the particle size of the positive electrode active material of the battery is continuously reduced. This is because the reduction in particle size of the positive electrode active material can increase the specific surface area and shorten the diffusion distance of active ions, thereby contributing to the improvement of energy density. However, the smaller the particle size of the positive electrode active material, the higher the surface energy thereof, resulting in the difficulty of dispersing the positive electrode active material in a solvent, and the poor stability of the formed positive electrode slurry, and the tendency of occurrence of a gel phenomenon. Although there is a solution for improving stability by increasing the molecular weight of the binder in the related art, the high molecular weight binder has a high viscosity, and there is a problem in that slurry gel occurs. Disclosure of Invention In view of the above, the present application provides a battery cell, a battery device, and an electric device, which aim to solve the problem of poor stability of a small-particle-diameter positive electrode active material slurry. In a first aspect, the application provides a battery cell comprising a positive electrode sheet, wherein the positive electrode sheet comprises a positive electrode film layer, the positive electrode film layer comprises a positive electrode additive, and the positive electrode additive comprises a first polymer and a second polymer; The first class of polymers includes fluoroolefin polymers; The second polymer comprises an anchoring group G and a flexible chain segment, wherein the anchoring group G comprises at least one of carboxyl, sulfonic acid group, phosphate ester group, amide group and ester group, and the main chain of the flexible chain segment comprises at least one of carbon-carbon single bond, carbon-oxygen single bond, ether bond, ester bond and amide bond. In the technical scheme of the application, the first polymer is used as the binder, so that the positive electrode active material and the conductive agent can be firmly bonded, and a mixed system formed by the positive electrode active material and the conductive agent can be adhered on the current collector, so that the situation that the positive electrode film layer is separated and falls off is reduced. The second polymer contains anchoring groups and soft chain segments, wherein the anchoring groups can enhance the adsorption capacity between the polymer and the surfaces of different particles and improve the dispersion performance, and the soft chain segments play a role in steric hindrance and can reduce the re-agglomeration condition after powder dispersion. Therefore, the present application can improve the stability of the small-particle size cathode active material slurry. In some embodiments, the soft segment further comprises at least one branch comprising at least one of a carbon chain, a benzene ring, an anhydride, a polyether, a cyclic ether. According to the technical scheme, the sliding capacity between particles can be improved by matching the branched chains of the flexible chain segments with the main chain, and when the positive electrode film layer is coated on the positive electrode current collector with higher compaction density, the flexibility of the formed positive electrode plate can be increased, so that the problem that the section is easy to be uneven when the film roll is cut is solved, and the risk of puncturing the diaphragm at the uneven position of the cutting edge can be reduced when the laminated battery is formed, and the stability of the battery is further improved. In some embodiments, the second class of polymers has the structural formula (I): According to the technical scheme, the rigid structures such as benzene rings and acid anhydrides are introduced into the branched chains of the second type polymers, so that the capability of embedding the second type polymers into the first type polymers can be enhanced, the crystallinity of the first type polymers is reduced, the flexibility of the positive pole piece is further enhanced, and the ethylene oxide and the anchoring groups are used as end caps, so that the dispersion capability of particles can be improved, and the flexibility of the formed positive pole piece is enhanced. In some embodiments, the anchoring group G is a group of formula (II) or formula (III): formula (II) Formula (III); Wherein, C n is alkyl carbon chain, and R' comprises at least one of hydrogen atom, C 1-C12 alkyl carbon chain, C 1-C12 alkyl alcohol and C 1-C12 alkyl hydroxylamine. In the technical scheme of the application, the anchoring group G comprises