充电状态下热滥用引发的电池热失控现象研究

Research on battery thermal runaway caused by thermal abuse under charging state

为了揭示充电行为对磷酸铁锂电池热失控现象的影响,选取6节12 Ah方形铝壳磷酸铁锂电池,对其中3节用0.3 C、0.6 C、0.9 C倍率电流动态充电的同时提供1000 W的加热功率直至引发热失控,计算电池热失控时的电量后,将另外3节电池充电至相应电量,再对电池进行静态下的加热直至引发热失控。研究发现:充电状态下电池热失控时的内部化学反应更加活跃,导致更多的能量转化成化学能,从而生成更多气体,转化成热能的部分相对较少,导致热失控后电池的温度相对较低。因此,对于充电状态下电池的安全管理,除了考虑温度因素以外,还更应该考虑气体产生带来的危害。

To investigate the influence of charging behavior on thermal runaway phenomena of lithium iron phosphate(LiFePO_(4))batteries,six 12 Ah square aluminum-cased LiFePO_(4) batteries were selected.Three of these batteries were dynamically charged at rates of 0.3 C,0.6 C,and 0.9 C while providing 1000 W of heating power until the thermal runaway occurred.The remaining three batteries were then charged to the same state of charge after calculating the energy capacity at the point of thermal runaway,and the batteries were subjected to static heating until inducing the thermal runaway.The results show that the internal chemical reactions become more active when the battery experiences thermal runaway under the charging state which leads to a higher conversion of energy into chemical potential energy,resulting in the generation of more gas.Consequently,a relatively smaller portion of energy is transformed into thermal energy,which results in a relatively lower temperature of the battery after thermal runaway.Therefore,when managing the safety of batteries under the charging state,it is important to consider not only the temperature factor but also the hazards associated with gas production.