PCM热物性对锂离子电池热失控蔓延的影响

Influence of PCM Thermophysical Properties on Thermal Runaway Spreading of Lithium-ion Batteries

针对大型锂离子电池的热失控蔓延问题,以相变材料为电池模组隔热材料,建立了电池组热失控防护三维数值计算模型。通过改变PCM隔板的潜热、厚度和导热系数,分析相变材料的热物性参数对锂离子电池热失控蔓延的影响特性。计算结果表明,单纯改变PCM隔板的潜热对热失控蔓延时间的影响很小,而增加隔板厚度可以有效延长,且厚度为8mm时可以达到规范要求的防护效果;隔板潜热为226kJ/kg,厚度在6mm以上时,导热系数为0.02W/m·K和2W/m·K模组平均热失控蔓延时间基本相同。

Aiming at the thermal runaway spreading problem of large lithium-ion batteries,a three-dimensional numerical calculation model for thermal runaway protection of battery packs was established by using phase change materials(PCMs)as the insulating materials of battery modules.By changing the latent heat,thickness and thermal conductivity of the PCM separator,the physical parameters of the phase change material are analysed for their influence on the thermal runaway spread of lithium-ion batteries.Calculation results show that simply changing the latent heat of the PCM spacer has little effect on the thermal runaway spreading time,while increasing the thickness of the spacer can be effectively prolonged,and when the thickness is 8mm,the protection effect required by the specification can be achieved;the latent heat of the spacer is 226kJ/kg,and the thickness of the spacer is more than 6mm,and the thermal conductivity of the thermal conductivity of the thermal runaway spreading time of the module is basically the same as that of the average of the thermal runaway spreading time of the module of 0.02W/m·K and 2W/m·K.