高比能锂离子电池过充失效机理研究

Study on overcharge failure mechanism of high specific energy lithium-ion power battery

对NCM811/SiO_(x)+C体系锂离子电池进行不同倍率及不同程度的过充,充分研究了动力电池过充过程中电池和材料发生的变化。揭示了高比能量电池过充失效的根本原因为过充过程中电解液在电极界面发生分解反应,产生大量的热导致隔膜破孔,内部短路。研究成果可为高镍体系电池安全性改善提供参考依据。

The overcharging of lithium ion batteries in NCM811/SiO_(x)+C system with different rates and state of charge(SOC)was studied to fully understand the changes of batteries and materials during the overcharging process of power batteries.The root cause of overcharge failure of batteries with high specific energy was heat accumulation and internal short-circuit.This work provides clues for the improvement of Li-ion power battery safety.