Patent ID: 11961964
Assignee: SOPHIA SCHOOL CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. A method of producing a lithium-ion secondary battery, comprising:
preparing a lithium-ion secondary battery, the lithium-ion secondary battery comprising at least a positive electrode, a negative electrode, and an electrolyte solution, the electrolyte solution of the prepared lithium-ion secondary battery comprising a solvent and a lithium salt; and
adding a zwitterionic compound to the electrolyte solution of the prepared lithium-ion secondary battery,
the negative electrode of the prepared lithium-ion secondary battery including at least a negative electrode active material and a solid electrolyte interface (SEI) film,
the SEI film being formed on a surface of the negative electrode active material prior to adding the zwitterionic compound to the electrolyte solution,
the film containing a lithium compound,
the zwitterionic compound containing a phosphonium cation and a carboxylate anion in one molecule,
wherein the method includes determining an amount of the zwitterionic compound to be added to the electrolyte solution of the lithium-ion secondary battery a capacity loss of the battery caused by the SEI film.