The invention discloses an ultrahigh-temperature safe
lithium ion battery electrolytic solution and a
lithium ion battery using the electrolytic solution. The electrolytic solution comprises 10-15% ofa
lithium salt, 1-5% of a high-temperature film-forming additive, 1-10% of a
flame-retardant additive and the balance of an
organic solvent, wherein the lithium salt is one or a mixture of more thantwo of
hexafluorophosphoric acid, lithium bis (fluorosulfonyl)
imide or lithium bis (trifluoromethylsulfonyl)
imide, the
organic solvent is formed by mixing carbonic ester,
carboxylic ester and a fluoroether
solvent according to a certain proportion, the carbonic ester accounts for 30%-70% of the total amount of the
lithium ion battery electrolytic solution, the
carboxylic ester accounts for 0%-10% of the total amount of the
lithium ion battery electrolytic solution, and the fluoroether accounts for 0%-10% of the total amount of the
lithium ion battery electrolytic solution. According to the invention, the electrolytic solution disclosed by the invention is a high-temperature
solvent and lithium salt with excellent
thermal stability, and a film-forming additive with excellent film-formingthermal stability and a proper
flame-retardant additive are added to realize the
flame-retardant effect of the electrolytic solution; and the lithium
ion battery disclosed by the invention can be normally used under the ultrahigh temperature condition of 100 DEG C while the battery has excellent safety performance.