过充条件下三元锂离子电池热安全性分析

Thermal safety analysis on ternary lithium ion battery under overcharge conditions

为探究锂离子电池在过充条件下的热安全性问题,以18650型三元锂离子电池为研究对象,开展单次与循环过充不同SOC电池在相同条件下的热安全性对比实验。通过锂离子电池到达初爆和热失控节点所用时间、节点处电池表面温度以及电池表面温度峰值,分析单次与循环过充电池的热稳定性和后果严重程度,为评估过充条件下锂离子电池热安全性提供评价指标,为民用航空运输中使用锂离子电池的设备的检验管理、行业的规范发展提供技术支持。结果表明:单次过充后的锂离子电池与循环过充后相比,初爆时间提前20%,温度升高8%,热失控时间提前15%。在综合分析电池热失控现象、最高温度和质量损失后,得出循环过充后锂离子电池的热稳定性优于单次过充电池,但其热失控后果更为严重。

To explore the thermal safety issues of lithium ion battery under the condition of overcharge,18650 type ternary lithium ion battery was used as the research object,and the thermal safety comparative experiment of batteries with different SOC of single and cyclic overcharged under the same conditions was conducted.The thermal stability and the severity of the consequences of the single and cyclic overcharged battery were analyzed by the time of battery to reach the initial burst and thermal runaway,the surface temperature of two nodes,and the battery surface temperature peak.The research was to provide evaluation indicators for evaluating the thermal safety of lithium ion batteries under overcharge conditions,and provide technical support for the inspection management of equipment using lithium ion batteries in civil air transportation and the standardized development of the industry.The result showed that,compared with cyclic overcharged batteries,the initial burst time of single overcharged batteries is 20%earlier and the temperature rises by 8%,and thermal runaway time is 15%ahead.After comprehensive analysis of battery thermal runaway phenomenon,maximum temperature and mass loss,it is concluded that the thermal stability of lithium ion battery after cyclic overcharged is better than that of single overcharged battery,but the consequences of thermal runaway are more serious.