锂离子电池安全材料的研究进展

Lithium-ion batteries are widely used in electric vehicles because of their cleanliness, fast charge and discharge, and high energy density. Recently, fires and explosions of electric vehicles have caused people to worry about the safety of lithium-ion batteries. Aiming at the safety problems of lithium-ion battery electrolyte such as flammability, explosiveness, and leakage, the latest research progress and advantages and disadvantages of adding flame retardant phosphate, ionic liquid and hydrofluoroethers into the electrolyte are reviewed. If the battery is overcharged, it will cause heat accumulation, which will cause a series of side reactions inside the battery. Two measures, redox protection and electropolymerization protection, are summarized to avoid battery overcharging. Due to the internal heat accumulation process in the dangerous accident of lithium batteries and the difficulty of maintaining the mechanical properties of the separator as the internal temperature of the battery rises, this article describes response strategies of the internal heat accumulation of lithium ion batteries in recent years from the thermal response switch cathode material and safety separator, which is expected to point out the direction for finally solving the safety problem of lithium-ion batteries.