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CN-122000407-A - Secondary battery, preparation method thereof and power utilization device

CN122000407ACN 122000407 ACN122000407 ACN 122000407ACN-122000407-A

Abstract

The application relates to the technical field of batteries, in particular to a secondary battery, a preparation method thereof and an electric device. The preparation method of the secondary battery comprises the steps of providing a positive electrode plate and electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer arranged on at least one side of the positive electrode current collector, the positive electrode active layer comprises a positive electrode active material, the positive electrode active layer further comprises a first reaction monomer, at least one of the positive electrode active layer and the electrolyte comprises a second reaction monomer, one of the first reaction monomer and the second reaction monomer comprises at least two epoxy groups, and the other one of the first reaction monomer and the second reaction monomer comprises a functional group capable of undergoing polymerization reaction with the epoxy groups. The scheme of the application can well improve the dissolution and migration problems of transition metals in the anode active material.

Inventors

  • ZHANG XINRAN
  • HAN YUZHEN
  • MA GUIXIN
  • HE JIANFU
  • YE YONGHUANG

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241101

Claims (20)

  1. 1. A method of manufacturing a secondary battery, comprising: Providing a positive electrode plate and electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer arranged on at least one side of the positive electrode current collector, and the positive electrode active layer comprises a positive electrode active material; the positive electrode active layer further includes a first reactive monomer, and at least one of the positive electrode active layer and the electrolyte includes a second reactive monomer; One of the first reactive monomer and the second reactive monomer comprises at least two epoxy groups, and the other comprises a functional group capable of undergoing a polymerization reaction with the epoxy groups.
  2. 2. The method for producing a secondary battery according to claim 1, wherein the molar ratio of the epoxy group to the functional group capable of undergoing a polymerization reaction with the epoxy group is (1-2): 1.
  3. 3. The method for producing a secondary battery according to claim 1 or 2, wherein the molar ratio of the epoxy group to the functional group capable of undergoing a polymerization reaction with the epoxy group is (1.5 to 2): 1.
  4. 4. The method for producing a secondary battery according to any one of claims 1 to 3, wherein the first reactive monomer contains at least two epoxy groups, and the second reactive monomer contains at least two functional groups capable of undergoing a polymerization reaction with the epoxy groups.
  5. 5. The method for manufacturing a secondary battery according to claim 4, wherein the first reactive monomer comprises one or more of a glycidyl ether type epoxy resin monomer, a biphenyl type epoxy resin monomer, a fluorine-containing type epoxy resin monomer, and a silicon-containing type epoxy resin monomer.
  6. 6. The method for producing a secondary battery according to claim 5, wherein the glycidyl ether type epoxy resin monomer comprises one or more of bisphenol A diglycidyl ether, resorcinol diglycidyl ether, and/or, The biphenyl epoxy resin monomer comprises And/or the number of the groups of groups, The fluorine-containing epoxy resin monomer comprises
  7. 7. The method according to any one of claims 1 to 6, wherein the functional group capable of undergoing a polymerization reaction with the epoxy group includes one or more of an amino group, a hydroxyl group, and a carboxyl group.
  8. 8. The method according to any one of claims 4 to 7, wherein the second reactive monomer comprises NH 2 -R 1 -NH 2 ,R 1 comprising an alkylene group having 2 to 10 carbon atoms.
  9. 9. The method for manufacturing a secondary battery according to claim 8, wherein the second reactive monomer comprises one or more of hexamethylenediamine and ethylenediamine.
  10. 10. The method for producing a secondary battery according to any one of claims 4 to 9, wherein the mass content of the first reactive monomer in the positive electrode active layer is 0.008% to 0.5%.
  11. 11. The method for manufacturing a secondary battery according to claim 10, wherein the mass content of the first reactive monomer in the positive electrode active layer is 0.08% -0.5%.
  12. 12. The method for producing a secondary battery according to any one of claims 4 to 11, wherein the electrolyte contains the second reactive monomer in an amount of 0.01 to 3% by mass in the electrolyte, or the positive electrode active layer contains the second reactive monomer in an amount of 0.001 to 0.08% by mass in the positive electrode active layer.
  13. 13. The method for producing a secondary battery according to claim 12, wherein the electrolyte contains the second reactive monomer, and the mass content of the second reactive monomer in the electrolyte is 0.1% to 0.7%.
  14. 14. The method for producing a secondary battery according to any one of claims 1 to 3, wherein the second reactive monomer contains at least two epoxy groups, and the first reactive monomer contains at least two functional groups capable of undergoing polymerization reaction with the epoxy groups.
  15. 15. The method according to claim 14, wherein the mass content of the first reactive monomer in the positive electrode active layer is 0.001% -0.08%.
  16. 16. The method for producing a secondary battery according to claim 14 or 15, wherein the electrolyte contains the second reactive monomer, and the mass content of the second reactive monomer in the electrolyte is 0.07% -4%.
  17. 17. The secondary battery is characterized by comprising a positive electrode plate and electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer arranged on at least one side of the positive electrode current collector, and the positive electrode active layer contains a positive electrode active material and is dispersed with epoxy resin.
  18. 18. The secondary battery according to claim 17, wherein the mass content of the epoxy resin in the positive electrode active layer is 0.01% -0.6%.
  19. 19. The secondary battery according to claim 17 or 18, wherein the mass content of the epoxy resin in the positive electrode active layer is 0.1% to 0.5%.
  20. 20. An electric device comprising the secondary battery according to any one of claims 17 to 19.

Description

Secondary battery, preparation method thereof and power utilization device Technical Field The application relates to the technical field of batteries, in particular to a secondary battery, a preparation method thereof and an electric device. Background Positive electrode materials of secondary batteries include ternary materials, lithium manganate, lithium cobaltate, lithium manganese iron phosphate, and the like, which generally contain transition metals. During the cycle of the secondary battery, these transition metals are easily extracted from the positive electrode material, dissolved into the electrolyte, and migrate to the negative electrode side through the electrolyte to deposit, resulting in deterioration of the performance of the secondary battery. Disclosure of Invention The present application has been made in view of the above-described problems, and an object of the present application is to solve the problems of dissolution and migration of transition metals in a positive electrode active material. In order to achieve the above object, the present application provides a secondary battery, a method of manufacturing the same, and an electric device. The first aspect of the present application provides a method for manufacturing a secondary battery, comprising: providing a positive electrode plate and electrolyte, wherein the positive electrode plate comprises a positive electrode current collector and a positive electrode active layer arranged on at least one side of the positive electrode current collector, and the positive electrode active layer contains a positive electrode active material; the positive electrode active layer further comprises a first reactive monomer, and at least one of the positive electrode active layer and the electrolyte comprises a second reactive monomer; One of the first reactive monomer and the second reactive monomer comprises at least two epoxy groups, and the other comprises a functional group capable of undergoing a polymerization reaction with an epoxy group. According to the embodiment of the application, the first reaction monomer is added into the positive electrode active layer, and the second reaction monomer is added into at least one of the positive electrode active layer and the electrolyte, so that the positive electrode plate is manufactured, or after the positive electrode plate, the electrolyte and other components are assembled into the secondary battery, the first reaction monomer can be subjected to polymerization reaction with the second reaction monomer to generate the epoxy resin. Specifically, in the case where the positive electrode active layer contains both the first reactive monomer and the second reactive monomer, since both the first reactive monomer and the second reactive monomer are dispersed in the positive electrode active layer, the first reactive monomer and the second reactive monomer can contact each other with a high probability, and the two reactive monomers that come into contact can undergo in-situ polymerization reaction to generate the epoxy resin. The epoxy resin produced will also be dispersed in the positive electrode active layer as the first reactive monomer, the second reactive monomer, and can be in contact with the positive electrode active material dispersed therein as well. In the case where the positive electrode active layer contains the first reactive monomer and the electrolyte contains the second reactive monomer, after the positive electrode tab, the electrolyte and other components are assembled into the secondary battery, the positive electrode active layer is immersed in the electrolyte, and the second reactive monomer may be diffused to the surface and inside of the positive electrode active layer along with the electrolyte, thereby contacting the first reactive monomer dispersed in the positive electrode active layer and performing in-situ polymerization in the positive electrode active layer to generate the epoxy resin. Similarly, the epoxy resin produced is dispersed in the positive electrode active layer as in the case of the first reactive monomer, and can be brought into contact with the positive electrode active material dispersed therein as well. In the case where the positive electrode active layer contains both the first reactive monomer and the second reactive monomer and the electrolyte contains the second reactive monomer, the reaction process of the two reactive monomers can be combined with the two cases. The positive electrode active material generally contains transition metals, and epoxy resin generated by the first reaction monomer and the second reaction monomer can be contacted with the positive electrode active material, so that the problems of dissolution and migration of the transition metals can be improved by using the epoxy resin, wherein the principles may include: 1) a part of epoxy resin may be distributed on the surface of the positive electrode active material, so tha