ELECTROLYTE SOLUTION OF LITHIUM-ION BATTERY AND LITHIUM SECONDARY BATTERY

An electrolyte solution of a lithium-ion battery and a lithium secondary battery. The electrolyte solution of a lithium-ion battery includes an organic solvent, a lithium salt and an additive, wherein the organic solvent includes fluorinated ethylene carbonate accounting for at least 5% of the total mass of the electrolyte solution, the additive comprises an additive A containing one or more compounds which have three or more carbon-carbon double bonds, and the electrolyte solution does not include a compound containing a sulfonyl group. The electrolyte solution of a lithium-ion battery is not only more environmentally friendly, but can also improve the swelling of the battery during the formation and high-temperature storage thereof, the discharge capacity of the battery, and the self-discharge performance of the battery under a high voltage.