锂离子电池安全材料的研究进展

Research progress of lithium ion batteries safety materials

锂离子电池因其清洁、充放电快、高能量密度等优点广泛应用于电动汽车。最近,电动汽车起火、爆炸事故引起人们对锂离子电池安全性的担忧。针对锂离子电池电解液易燃、易爆、易泄漏等安全问题,本文综述了电解液中加入阻燃剂磷酸酯、离子液体、氢氟醚的最新研究进展及其优缺点。电池如果在过充危险状况下会造成热积累,进而引发电池内部一系列危险副反应。本文还总结了氧化还原保护和电聚合保护两种措施来避免电池过度充电的研究进展。由于锂电池发生危险事故前内部会有一个热积累过程以及随着电池内部温度上升隔膜难以保持其力学性能,本文分别从热响应开关正极材料和安全隔膜两部分阐述了近年来锂离子电池内部热积累的应对策略,以期为最终解决锂离子电池的安全问题指明方向。

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.