三元锂离子电池高温诱导热失控试验研究

Experimental Study on High Temperature Induced Thermal Runaway of Ternary Lithium-Ion Battery

针对频频发生的锂电池热失控事故,本文使用绝热加速量热仪(accelerating rate calometry,ARC)的“Ramp”程序,外部热诱导一款2.6 Ah的圆柱形Li(Ni _(0.5) Co_(0.2) Mn_(0.3))O_(2)(简称NCM523)电池触发热失控,探究了100%,75%和50%不同荷电状态(state of charge,SOC)电池热失控的特征参数,并比较了“Ramp”程序和广泛使用的“H-W-S”程序的差异。同时,对100%,75%和50%不同SOC电池热失控起始温度T_(1)、触发温度T_(2)和最高温度T_(3)进行比较分析。研究结果表明,电池SOC越高,电池的热稳定性和安全性越差,热失控爆炸所释放的能量越大,热失控最高温度为715.4℃。三者热失控过程中所释放的能量分别为32.68,32.5和14.27 kJ,相当于7.37,7.32,3.22 g三硝基甲苯(trinitortoluene,TNT)爆炸的威力。“Ramp”程序较“H-W-S”程序试验耗时较短,可模拟环境升温对电池的影响。该研究为电池热失控的预警及防控提供了理论指导。

In order to explore the occurrence process of thermal runaway of lithium battery,accelerating rate calometry’Ramp program was used to induce a 2.6 Ah cylindrical NCM 523 battery to contact heating runaway,exploring the characteristic parameters of thermal runaway of batteries with different state of charge(100%,75% and 50%),and comparing the differences between"ramp"program and widely used"H-W-S"program.By comparing the starting temperature T_(1),triggering temperature T_(2) and maximum temperature T_(3) of thermal runaway of 100%,75%and 50%SOC batteries,it is concluded that the higher the SOC of the battery,the worse the thermal stability of the battery,the worse the safety of the battery,the greater the energy released by the thermal runaway explosion,and the maximum temperature of thermal runaway is 715.4℃.The energy released in the process of thermal runaway is 32.68 kJ,32.5 kJ and 14.27 kJ,respectively,which is equivalent to the power of 7.37 g,7.32 g and 3.22 g TNT explosion,respectively.The"Ramp"program takes less time than the"H-W-S"program,which can simulate the impact of environmental temperature rise on the battery.This paper explores the process of lithium battery thermal runaway,and provides guidance for the early warning and prevention of battery thermal runaway.