磷酸铁锂电池热失控过程中释放能量分析

Energy released during thermal runaway of lithium iron phosphate battery

利用锂离子电池热失控实验平台进行不同荷电状态(SOC)磷酸铁锂电池的热失控实验,分别将热失控前后的电池拆解,利用氧弹量热仪测量各部分的燃烧热值并进行对比分析。通过加权计算的方法得到电池热失控前后的能量,分析磷酸铁锂电池热失控过程中释放的能量。结果表明,磷酸铁锂电池热失控过程释放的能量与SOC成正相关关系,满电态20 Ah软包磷酸铁锂电池在热失控时释放的能量最大,可达2342 kJ。

In this paper,a thermal runaway experiment on a lithium iron phosphate battery is carried out for varying states of charge(SOC)on an experimental platform for thermal runaway of lithium ion batteries,wherein the sample battery is disassembled before and after thermal runaway and compared by measuring the heat of combustion on different portions of the battery with an oxygen bomb calorimeter.The energy released during the runaway of the lithium iron phosphate battery is examined against the energy contained in the battery before and after thermal runaway,yielded by weighting algorithm.The result shows that the energy released during thermal runaway of lithium iron phosphate battery is positively correlative to SOC;and the highest energy is released during thermal runaway of a 20 Ah lithium iron phosphate battery when it is fully charged,the maximum energy released is up to 2342 kJ.