Lithium-ion battery (LIB) eruptions play an important role in battery fires in electric vehicles. This study aims to quantitatively reveal the eruption process of LIBs. A 50-Ah commercial prismatic cell with a Li(Ni_0.6Mn_0.2Co_0.2)O₂ cathode was triggered to thermal runaway using external heating in a sealed chamber with different initial nitrogen atmospheres under 0%, 25%, 50%, 75%, and 100% state of charge (SOC) values, respectively. Based on the in-chamber pressure under 100% SOC value, a quantitative analysis method for the LIB eruption process was proposed, and applied to the other SOC values at different test conditions. Results show that using a LIB eruption index (i.e., product of the in-chamber pressure rise rate and the cubic root of the chamber volume) based on the gas explosion index can effectively and quantitatively analyze the LIB eruption process at 100% SOC. According to the variation of the explosion indices with time, LIB eruption processes can be divided into ultrafast, fast, and slow phases. This quantitative analysis method is also effective in case of the eruption process at different SOC values under different conditions. Thus, the results of this study can provide guidance for fire early warning systems, fire suppression strategies, proper battery selections, and storage designs.

锂离子电池（LIB）的爆发在电动汽车的电池起火中起着重要作用。这项研究旨在定量揭示LIB的爆发过程。具有Li（Ni _0.6 Mn _0.2 Co _0.2）O ₂的50Ah商业方形电池在密封室中使用外部加热，分别在0％，25％，50％，75％和100％的荷电状态（SOC）值下，在不同的初始氮气氛下，将阴极触发至热失控状态。基于100％SOC值下的室内压力，提出了LIB喷发过程的定量分析方法，并应用于不同测试条件下的其他SOC值。结果表明，使用基于气体爆炸指数的LIB爆发指数（即腔内压力上升速率与腔室容积的立方根的乘积）可以有效，定量地分析100％SOC下的LIB爆发过程。根据爆炸指数随时间的变化，LIB爆发过程可分为超快，快和慢两个阶段。对于在不同条件下以不同SOC值进行喷发过程的情况，这种定量分析方法也是有效的。因此，这项研究的结果可以为火灾预警系统，灭火策略，正确的电池选择和存储设计提供指导。