Search

CN-122025815-A - Lithium ion battery and application thereof

CN122025815ACN 122025815 ACN122025815 ACN 122025815ACN-122025815-A

Abstract

The invention provides a lithium ion battery and application thereof, wherein the lithium ion battery comprises a positive electrode plate, a negative electrode plate, a diaphragm, electrolyte and an electrolyte, wherein the positive electrode plate comprises a positive electrode material, the positive electrode material comprises a positive electrode active substance and a sulfur simple substance coated on the surface of the positive electrode active substance, the diaphragm is arranged between the positive electrode plate and the negative electrode plate, the electrolyte comprises an additive, and the structural formula of the additive is shown as formula (I); Wherein R1, R2, R3 and R4 are each selected from at least one of H, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms or a substituted or unsubstituted alkoxy group having 3 to 12 carbon atoms, and when substituted, the substituent is halogen or an alkyl group having 1 to 12 carbon atoms. The lithium ion battery and the application thereof provided by the invention can reduce self-discharge at high temperature and reduce battery capacity loss.

Inventors

  • YU LE
  • Hu Ajuan

Assignees

  • 远景动力技术(湖北)有限公司
  • 远景动力技术(江苏)有限公司
  • 远景睿泰动力技术(上海)有限公司

Dates

Publication Date
20260512
Application Date
20260304

Claims (10)

  1. 1. A lithium ion battery, comprising: the positive electrode plate comprises a positive electrode material, wherein the positive electrode material comprises a positive electrode active substance and a sulfur element coated on the surface of the positive electrode active substance; A negative electrode plate; a separator arranged between the positive electrode plate and the negative electrode plate, and An electrolyte comprising an additive, the additive comprising a first additive having the structural formula (I); Wherein R1, R2, R3 and R4 are each selected from at least one of H, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms or a substituted or unsubstituted alkoxy group having 3 to 12 carbon atoms, and when substituted, the substituent is halogen or an alkyl group having 1 to 12 carbon atoms.
  2. 2. The lithium ion battery of claim 1, wherein the first additive is present in the electrolyte in an amount of 0.1wt% to 2wt%.
  3. 3. The lithium ion battery according to claim 1, wherein the content of the elemental sulfur in the positive electrode material is 0.1wt% to 2wt%.
  4. 4. The lithium ion battery of claim 1, wherein in the lithium ion battery, the mass ratio of the first additive to the elemental sulfur is 1:30 to 5:3.
  5. 5. The lithium ion battery of claim 1, wherein the electrolyte further comprises a lithium salt selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (trifluoromethane) sulfonimide, lithium dioxalate borate, lithium difluorodioxalate phosphate, lithium difluorooxallate, lithium difluorophosphate, or lithium trifluoromethane sulfonate.
  6. 6. The lithium ion battery of claim 5, wherein the lithium salt comprises lithium hexafluorophosphate and lithium bis-fluorosulfonyl imide, the content of the lithium hexafluorophosphate in the electrolyte is 11wt% to 15wt%, and the content of the lithium bis-fluorosulfonyl imide in the electrolyte is 0.5wt% to 3wt%.
  7. 7. The lithium ion battery of claim 1, wherein the electrolyte further comprises a non-aqueous solvent selected from at least one of a carbonate solvent, a carboxylate solvent, an ether solvent, or a nitrile solvent.
  8. 8. The lithium ion battery of claim 1, wherein the additive comprises a second additive comprising vinyl disulfate, the second additive being present in the electrolyte in an amount of 0.1wt% to 2wt%.
  9. 9. The lithium ion battery according to claim 1, wherein the positive electrode active material is at least one selected from lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, or lithium nickel cobalt aluminum oxide.
  10. 10. An electronic device comprising a lithium-ion battery according to any one of claims 1-9.

Description

Lithium ion battery and application thereof Technical Field The invention relates to the technical field of power batteries, in particular to a lithium ion battery and application thereof. Background Lithium ion batteries play an increasingly important role in modern society and are widely applied to the fields of energy storage systems, portable energy storage, artificial satellites, aerospace, electronic equipment and the like. The huge potential of the energy storage battery in different fields is demonstrated, and the energy storage battery not only contributes to improving the energy utilization efficiency, but also promotes sustainable development and environmental protection. With the progress of technology, the demand of lithium ion batteries is rapidly growing, and although the lithium battery technology is relatively mature, problems in terms of safety, service life, energy density and the like still exist to be solved. Disclosure of Invention The invention provides a lithium ion battery and application thereof, wherein a CEI film with a three-dimensional network structure is formed by regulating and controlling the composition of electrolyte and the structure of a positive electrode material, so that the floating charge capacity of a battery core is improved, the self-discharge at high temperature is reduced, the capacity loss during storage can be reduced, and the cycle performance of the battery is improved. In order to solve the above technical problems, the present invention provides a lithium ion battery, comprising: the positive electrode plate comprises a positive electrode material, wherein the positive electrode material comprises a positive electrode active substance and a sulfur element coated on the surface of the positive electrode active substance; A negative electrode plate; a separator arranged between the positive electrode plate and the negative electrode plate, and An electrolyte comprising an additive, the additive comprising a first additive having the structural formula (I); Wherein R1, R2, R3 and R4 are each selected from at least one of H, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 12 carbon atoms or a substituted or unsubstituted alkoxy group having 3 to 12 carbon atoms, and when substituted, the substituent is halogen or an alkyl group having 1 to 12 carbon atoms. In one embodiment of the present invention, the first additive is contained in the electrolyte in an amount of 0.1wt% to 2wt%. In an embodiment of the present invention, the content of the elemental sulfur in the positive electrode material is 0.1wt% to 2wt%. In an embodiment of the present invention, in the lithium ion battery, a mass ratio of the first additive to the elemental sulfur is 1:30 to 5:3. In an embodiment of the present invention, the electrolyte further includes a lithium salt selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium difluorosulfonimide, lithium bis (trifluoromethyl) sulfonimide, lithium dioxalate borate, lithium difluorodioxalate phosphate, lithium difluorooxalato borate, lithium difluorophosphate, or lithium trifluoromethane sulfonate. In an embodiment of the present invention, the lithium salt includes lithium hexafluorophosphate having a content of 11wt% to 15wt% in the electrolyte and lithium difluorosulfonimide having a content of 0.5wt% to 3wt% in the electrolyte. In an embodiment of the present invention, the electrolyte further includes a non-aqueous solvent selected from at least one of a carbonate solvent, a carboxylate solvent, an ether solvent, or a nitrile solvent. In one embodiment of the present invention, the additive includes a second additive including vinyl disulfate, and the second additive is contained in the electrolyte in an amount of 0.1wt% to 2wt%. In an embodiment of the present invention, the positive electrode active material is selected from at least one of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese oxide, or lithium nickel cobalt aluminum oxide. The invention also provides electronic equipment comprising the lithium ion battery. In summary, the invention provides a lithium ion battery and application thereof, wherein the composition of electrolyte and the structure of a positive electrode material are regulated, the surface of the positive electrode material is coated with elemental sulfur, a first additive is added into the electrolyte, and when the lithium ion battery is charged for the first time to form a CEI film, the elemental sulfur and the first additive undergo a sulfur crosslinking reaction to form the CEI film with a three-dimensional network structure, so that the protection area is effectively improved. In addition, after the sulfur simple substance is crosslinked, active oxygen released by the positive