基于主动降温的热失控锂离子电池热扩散抑制研究

Research on Thermal Diffusion Suppression of Lithium-Ion Battery for Thermal Runaway Based on Active Cooling

为解决锂离子电池包在使用过程中的热扩散问题,选用某型号方形三元锂离子电池,采用乙二醇水溶液作为冷却介质对热失控电芯进行主动浇注降温,探究不同浇注量下的热失控电芯及其相邻电芯的温度变化规律,并模拟实车环境研究水泵转速对浇注流速的影响。试验结果表明:冷却液的浇注量、浇注流速是影响热扩散发生的重要变量,当浇注量为1.5L、流速为0.69L/min时,可将热失控电芯的最高温度由713℃降低到556℃,有效减少热失控电芯向相邻电芯的热量传递,避免相邻电芯发生热失控,阻止电池包内热扩散的发生。

In order to solve the problem of thermal diffusion of lithium-ion battery pack in use,this paper selects a certain type of square ternary lithium-ion battery,choosing glycol aqueous solution as the cooling medium to pour and cool the thermal runaway cell actively,so as to explore the temperature change law of the thermal runaway cell and its adjacent cells under different pouring amount,also the influences of water pump on the pouring speed are studied by stimulating a real vehicle environment.The experiment results show that the pouring amount and pouring flow rate of coolant are important variables affecting the occurrence of thermal diffusion.When the pouring amount is 1.5 L and the flow rate is 0.69 L/min,the maximum temperature of the thermal runaway cell is reduced from 713℃to 556℃,effectively reducing the heat transfer from the thermal runaway cell to the adjacent cells,avoiding the thermal runaway of the adjacent cells,and preventing the occurrence of thermal diffusion in the battery pack.