不同类型添加剂细水雾抑制锂电池组热失控传播试验研究

Experimental study on inhibition of thermal runaway propagation of lithium battery pack by water mist with different additives

以18650型三元锂电池组为研究对象,探究了锂电池组热失控传播的特征,进而研究了在不同灾害时刻施加不同类型添加剂细水雾对锂电池组热失控传播的抑制效果及抑制机理。结果表明:热失控在三角形布置的电池模组中的传播可划分为热失控引发、热失控层间传播、热失控同层传播3个特征时刻,由于存在上一层的预热作用,同层传播比层间传播更为迅速。在不同灾害时刻分别施加纯水细水雾、含1%CAB-35细水雾和含4%APG0810细水雾,发现细水雾抑制锂电池热失控传播效果与其对单体目标电池的降温效果存在一致性。含4%APG0810细水雾可显著降低目标电池热失控最高温度,在抑制热失控传播上具有最优效果,对热失控同层及层间传播均可起到抑制作用;热失控降温不明显的纯水细水雾和含1%CAB-35细水雾对热失控层间传播可起到抑制作用,而对热失控同层传播无法抑制。通过不同添加剂的溶液性能测试发现,含4%APG0810细水雾抑制能力显著优于其余2种的原因是4%APG0810具有最低的表面张力和接触角,并且其起泡性和泡沫稳定性也最佳,这些效果的共同作用提升了其对热失控传播的抑制效果。

Taking 18650 ternary lithium battery as the research object,this paper explores the characteristics of thermal runaway propagation of lithium battery,and then studies the effect and mechanism of inhibition of thermal runaway propagation by applying different types of additive water mist at different disaster times.The results show that the propagation of thermal runaway in the triangle-arranged battery module can be divided into three characteristic moments:thermal runaway initiation,thermal runaway peer layer propagation and thermal runaway interlayer propagation.Due to the preheating effect of the upper layer,the thermal runaway peer layer propagation is faster than the interlayer propagation.At different disaster times,pure water mist,1%CAB-35 water mist and 4%APG0810 water mist were applied respectively.It was found that the effect of water mist on restraining thermal runaway propagation of lithium battery was consistent with its cooling effect on single target battery.4%APG0810 water mist can significantly reduce the maximum thermal runaway temperature of the target battery,and has the best effect on inhibiting thermal runaway propagation,which can inhibit thermal runaway propagation in the same layer and between layers.1%CAB-35 water mist and pure water mist with no obvious thermal runaway cooling can inhibit the thermal runaway propagation between layers,but can not inhibit the thermal runaway propagation in the same layer.Through the solution performance test of different additives,it was found that the inhibition ability of 4%APG0810 water mist was significantly better than the other two,because 4%APG0810 has the lowest surface tension and contact angle,and its foaming property and foam stability are also the best.The combined effect of these effects im‑proves the inhibition effect of thermal runaway propagation.