Patent ID: 11961964
Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 11:
12. A method of using a zwitterionic compound to restore capacity of a lithium-ion secondary battery, comprising:
identifying a battery as having a deteriorated capacity, wherein the battery having the deteriorated capacity comprises at least a positive electrode, a negative electrode, and an electrolyte solution, the electrolyte solution comprising a solvent and a lithium salt, and the negative electrode including at least a negative electrode active material and a solid electrolyte interface (SEI) film formed on a surface of the negative electrode active material;
determining a capacity loss of the battery having the deteriorated capacity;
selecting an amount of a zwitterionic compound to add to the electrolyte solution of the lithium-ion secondary battery having the deteriorated capacity based on the capacity loss;
preparing the zwitterionic compound; and
restoring capacity of the lithium-ion secondary battery having the deteriorated capacity by adding the zwitterionic compound to the electrolyte solution of the lithium-ion secondary battery having the deteriorated capacity and the SEI film on the surface of the negative electrode active material,
wherein the zwitterionic compound contains a phosphonium cation and a carboxylate anion in one molecule, and
the deteriorated capacity represents a capacity being lower than an initial capacity of the lithium-ion secondary battery.