Abstract: Electrolyte is an important component part of lithium ion battery，which plays an important role on the performances，such as cycle performance and safety，of lithium ion batteries.The recent research progress related to electrolyte salts and primary organic solvents in China and abroad was reviewed.The safety performance of battery materials was summarized from electrolytes and electrolyte additives two aspects.The current research status of the improvements of co-solvents and the flame retarded additives was also introduced.

Key words: lithium ion battery, electrolyte, safety, flame retardancy, thermal stability