锂离子电池热解气体爆炸极限测定及其危险性分析

为定量研究锂离子电池热失控的危险性，利用锂离子电池在滥用条件下释放气体的种类及体积分数，计算锂离子电池热解气体爆炸极限并研究锂电池荷电状态对热解气体爆炸极限的影响。结果表明:在一定热失控条件下锂离子电池荷电状态为100%时其热解气爆炸下限为6.22%，上限为38.4%，在相同热失控条件下，锂离子电池热解气体的爆炸极限范围随着荷电状态的升高而增大，锂电池的荷电状态对热解气体的爆炸上限影响较大而对爆炸下限影响较小。在相似条件下，锂离子电池热解气体的爆炸极限范围比普通烃类气体大，一旦锂电池发生热失控会对锂离子电池运输造成潜在威胁。

Determination on explosion limit of pyrolysis gas released by lithium-ion battery and its risk analysis

In order to quantitatively study the risk of thermal runaway for lithium-ion battery, the explosion limit of pyrolysis gas was calculated and the influence of State of Charge (SOC) on the explosion limit of pyrolysis gas was studied for lithium-ion battery throught utilizing the type and volume fraction of gas released by lithium-ion battery under the abusive conditions. The results showed that under a certain thermal runaway conditions, when the SOC of lithium-ion battery is 100%, the lower explosion limit of pyrolysis gas is 6.22%, and the upper limit is 38.4%. Under the same thermal runaway conditions, the explosion limit range of pyrolysis gas increases with the increase of SOC, and the SOC of lithium battery has larger influence on the upper explosion limit of pyrolysis gas and less influence on the lower explosion limit. Under similar conditions, the explosion limit range of pyrolysis gas for lithium-ion battery is larger than ordinary hydrocarbon gas. Once the lithium battery occurs thermal runaway, it will cause a potential threat to the transport of lithium-ion battery.