液氮抑制外部加热和过充锂电池模组热失控

Liquid nitrogen suppresses thermal runaway of lithium-ion battery modulesunder external heating and overcharge

为抑制锂离子电池模组的热失控传播,构建液氮(LN)对热失控的抑制试验系统,揭示在外部加热和过充条件下,LN对锂离子电池模组热失控传播的抑制作用。结果表明:外部加热条件下,热失控自紧贴加热板的电池向两侧传播,共6块热失控电池;同条件下,注氮后热失控电池温度降低超过100℃,峰值温度降低70℃以上,LN冷却效率为42.9%,有效利用率为4.1%,热失控剧烈程度降低,传播被阻断;改变加热板位置使LN不直接接触热失控电池时,LN的冷却效率为18.3%,有效利用率仅为2.1%,远低于接触组,且热失控电池回温至207℃,LN不能终止电池热失控进程,LN直接接触热失控电池时达到最佳抑制效果。过充条件下,电池模组内共7块热失控电池,峰值温度均超过345℃;注氮组无热失控电池,电池峰值温度为127.4℃,LN冷却效率为41.7%,在电池模组压降时注氮可防止热失控发生。

In order to inhibit the thermal runaway propagation of lithium-ion battery modules,a test system was constructed to reveal the inhibition effect of LN on thermal runaway propagation of lithium-ion battery modules under the conditions of external heating and overcharging.Results show that under external heating conditions,thermal runaway propagates from the battery immediately adjacent to the heating plate to both sides,with a total of 6 thermal runaway batteries.The temperature of the thermal runaway battery is reduced by more than 100℃after LN injection under the same conditions,and the peak temperature is reduced by more than 70℃,with LN cooling efficiency of 42.9%and effective utilization of 4.1%,the thermal runaway is reduced to a lower degree of severity,and the propagation is blocked.When the position of the heating plate is changed so that the LN does not directly contact the thermal runaway battery,the cooling efficiency of LN is 18.3%.The effective utilization rate is only 2.1%,which is much lower than that of the contact group,while the thermal runaway battery is warmed back up to 207℃,LN cannot terminate the process of thermal runaway of the battery.LN achieves the optimal inhibition effect when directly contacting the thermal runaway battery.Under overcharging conditions,there are 7 thermal runaway batteries in the battery module,and the peak temperature exceeds 345℃.However,the LN injection group has no thermal runaway battery,the peak temperature of the battery is 127.4℃,and the cooling efficiency of LN is 41.7%.LN can terminate the thermal runaway process when the voltage of the battery module drops.This work is expected to provide a research reference for suppressing thermal runaway propagation in lithium-ion battery modules.