极寒环境下动力锂离子电池特性

Characteristics of Power Lithium-Ion Batteries at Extreme Cold Environment

针对极地无人机系统供电保障问题,为极地锂离子电池开发及电池管理技术研究提供依据,对12 A·h三元镍钴锰酸锂电池在极寒环境下的特性展开了实验研究.结果表明:在0℃以下,随着环境温度的降低,电池在不同放电倍率下的可用容量迅速减小,最大放电深度的衰减速率不断加快,欧姆内阻与极化内阻均显著增大且极化内阻的变化更为突出,开路电压明显降低;在低于-40℃的环境温度下,放电前对电池表面进行预热能显著改善电池放电性能,预热温度的变化不影响相同倍率放电时电池表面的平衡温度,同时采取预热与保温措施能够有效恢复电池的容量特性与功率特性.

Research on characteristics of power Li-ion batteries at extreme cold environment is the most necessary task for optimizing the battery design and the battery management system of unmanned aerial vehicle powered by Li-ion batteries in the application of polar research.A series of experiments are taken to explore the characteristics of a 12 A·h Li(NiCoMn)O2 lithium battery at extreme cold environment.The results show that the available capacities of battery under different discharge rates decrease rapidly at subzero temperatures,and the attenuation rate of the maximum depth of discharge speed up with falling temperature.Meanwhile,the discharge internal resistances,especially the polarization resistance,increase substantially.The open-circuit voltage is reduced evidently.Moreover,the implement of preheating before discharging can well recover battery performance at the ambient temperatures below-40℃.The equilibrium temperature of battery surface remains unchanged under the same discharge rate even with changing preheating temperature.The capacity and power characteristics of battery can be recovered effectively by utilizing both the preheating and heat insulation methods at the same time.