ELECTROLYTE SOLUTION, AND SECONDARY BATTERY, BATTERY MODULE, BATTERY PACK AND ELECTRICAL APPARATUS THEREOF

Provided are an electrolyte solution, comprising an organic solvent, an electrolyte lithium salt, and an additive; wherein the organic solvent comprises a fluorinated solvent; the electrolyte lithium salt comprises a fluorine-containing sulfonylimide lithium salt; and the additive comprises a lithium halide salt. The electrolyte solution of the present application has good conductivity and flame retardancy, and a lithium-ion battery comprising the electrolyte solution has at least one of improved energy density, safety performance, output performance, and cycling performance.