相变材料介质阻断电池热失控传播特性研究

Characteristic of Phase Change Material for Preventing Thermal Runaway Propagation Between Batteries

针对锂离子电池热失控传播问题,以石蜡/膨胀石墨复合相变材料为电池模组热管理介质,建立电池热失控传播二维数值计算模型。通过改变膨胀石墨与石蜡的质量分数得到不同导热系数与相变焓的复合材料,探究关键设计参数对电池热失控传播的阻断特性。研究结果表明相变材料能够有效延缓甚至阻断热失控的传播,当导热系数较低或较高(如0.3和21.01 W·m^(-1)·K^(-1))时皆能阻断热失控传播,对于中间导热系数材料的模组,首次热失控传播时间间隔随导热系数升高而增加,而后续传播间隔随着导热系数升高而减小。

Focusing on the problem of battery thermal safety,a two-dimensional thermal runaway propagation model is established for a battery module,in which the paraffin/expanded graphite composite phase change material serves as thermal management media.The materials with different thermal conductivity and phase change enthalpy are obtained by adjusting the mass fractions of expanded graphite,and the features of preventing thermal runaway propagation are investigated.The results show that phase change material can delay or even prevent thermal runaway propagation.The thermal runaway propagation inhibition can achieve by the phase change materials with lower and higher thermal conductivity(e.g.0.3 and 21.01 W·m^(-1)·K^(-1)).For materials with intermediate thermal conductivity,with the increase of thermal conductivity,the duration of initial thermal runaway propagation increases and the time interval of later thermal runaway propagation decreases.