Electrolyte for lithium-ion battery, lithium-ion battery, battery module, battery pack, and apparatus

Abstract

This application provides an electrolyte for lithium-ion battery, a lithium-ion battery, a battery module, a battery pack, and an apparatus. The electrolyte provided in this application includes a non-aqueous solvent, and a lithium salt and an additive that are dissolved in the non-aqueous solvent, and the additive includes a cyclosiloxane and a fluoroether. This application further provides a lithium-ion battery including the foregoing electrolyte. In the electrolyte provided in this application, the cyclosiloxane and the fluoroether are used together to synergistically react on a surface of the positive electrode, combining silicon and oxygen containing groups and fluorine and oxygen containing groups to form an interface film containing silicon, oxygen, and fluorine, which not only ensures density of the interface film, but also strengthens oxidation resistance and thermal stability of the interface film, greatly improving both storage performance and cycling performance of the lithium-ion battery under high temperature.