The invention discloses a
lithium ion battery electrolytic solution, which comprises a film-forming additive, wherein the film-forming additive comprises
vinylene carbonate,
ethylene sulfate, 1,3-
propane sultone and
lithium difluorophosphate, wherein the
vinylene carbonate accounts for 0.2%-3% of the total
mass of the electrolytic solution, the
ethylene sulfate accounts for 0.5%-5% of the total
mass of the electrolytic solution, the 1,3-
propane sultone accounts for 0.2%-3% of the total
mass of the electrolytic solution, and the
lithium difluorophosphate accounts for 0.2%-2% of the total mass of the electrolytic solution. According to the invention,
vinylene carbonate and
ethylene sulfate in the electrolytic solution form a stable and compact SEI film on the surface of the negative
electrode of the battery in the formation, charging and discharging processes, and 1,3-
propane sultone and lithium
difluorophosphate form a passive film on the surface of the positive
electrode, so that the high-temperature gas production performance of the battery is improved, the damage to the negative
electrode due to
dissolution of positive electrode
transition metal elements in the quick charge cycleprocess is inhibited, the film forming structure of the positive electrode and the negative electrode can be improved, the
side reaction is reduced, and the battery is ensured to have good high-ratecharging performance and cycle life.