Ouyang Dongxu, Chen Mingyi, Liu Jiahao, Wei Ruichao, Weng Jingwen, Wang Jian
State Key Laboratory of Fire Science, University of Science and Technology of China Hefei 230022 China.
School of Environment and Safety Engineering, Jiangsu University Zhenjiang 212013 China.
RSC Adv. 2018 Sep 27;8(58):33414-33424. doi: 10.1039/c8ra05564e. eCollection 2018 Sep 24.
A lithium-ion battery (LIB) may experience overcharge or over-discharge when it is used in a battery pack because of capacity variation of different batteries in the pack and the difficulty of maintaining identical state of charge (SOC) of every single battery. A series of experiments were established to investigate the thermal and fire characteristics of a commercial LIB under overcharge/over-discharge failure conditions. According to the results, it is clear that the batteries experienced a clear temperature rise in the overcharge/over-discharge process. The temperature rise worsened and required less time when the battery was overcharged/over-discharged to failure with the increasing charge/discharge rate. Besides, the closer the position to the opening of the battery, the higher the surface temperature. It was demonstrated that LIBs can fail when overcharged/over-discharged to a critical degree regardless of the charge/discharge rate. Under different rates, the final capacities were around a critical value. Finally, there existed an explosion phenomenon in the external heating test of battery failure after overcharge, whereas the fire behaviors of the over-discharged battery were much more moderate.
当锂离子电池（LIB）用于电池组时，由于电池组中不同电池的容量变化以及难以使每个电池保持相同的荷电状态（SOC），可能会出现过充电或过放电情况。开展了一系列实验来研究商用锂离子电池在过充电/过放电故障条件下的热特性和着火特性。根据实验结果，很明显电池在过充电/过放电过程中温度明显升高。随着充电/放电速率的增加，当电池过充电/过放电至失效时，温度上升加剧且所需时间减少。此外，距离电池开口位置越近，表面温度越高。结果表明，无论充电/放电速率如何，锂离子电池过充电/过放电至临界程度时都会失效。在不同速率下，最终容量都在一个临界值左右。最后，过充电后电池失效的外部加热试验中存在爆炸现象，而过放电电池的着火行为则较为缓和。
