18650 型锂离子电池一维热失控传播试验研究

对18650 型锂离子电池在线性水平排列方式下，单体电池和电池组热失控的热量传递、温度变化、烟气变化等进行了研究。将单体锂离子电池热失控过程划分为初始阶段、燃爆阶段和后期燃烧阶段。研究了热失控传播过程，定量分析导热系数k的变化，指出电池距离外部热源越近，越早发生热失控；距离热源较远的电池由于导热系数k 减小，发生热失控的时间变长，燃爆最高温度降低；当距离超长时，热失控传播被阻断。锂离子电池热失控烟气成分主要包含SO2、NO2、CO、HCl 和NH3 等气体，其中，NO2 和SO2 占比较高，分别达到了47%和27%。

Experimental study on thermal runaway propagation of 18650 lithium ion battery in linear horizontal arrangement

In this paper,the common 18650 lithium-ion battery is taken as the experimental object,the fire behavior,heat transfer,temperature change and the concentration change of smoke components in the process of thermal runaway of single lithium-ion battery and lithium-ion battery pack under the linear horizontal arrangement mode were studied.Combined with the experimental phenomena and temperature changes,the thermal runaway process of single lithium-ion battery was divided into initial stage,deflagration stage and late combustion stage.The thermal runaway propagation process of lithium-ion battery with linear horizontal arrangement is studied.The change of thermal conductivity k is quantitatively analyzed.It is proposed that the closer the battery is to the heat source,the earlier thermal runaway occurs.For the battery far away from the heat source,due to the decrease of the thermal conductivity k,the less heat is obtained,the longer the thermal runaway occurs,and the maximum temperature at the deflagration stage is also reduced.When the distance is long enough,the thermal conductivity decreases to the minimum,and the battery behind can not receive enough heat,and the propagation process of thermal runaway will be blocked.It was concluded that the smoke released from thermal runaway of lithium-ion battery pack mainly contained SO2,NO2,CO,HCl and NH3,and the concentrations of NO2 and SO2 accounted for 47%and 27%respectively.