电动汽车用软包动力锂电池热-结构耦合分析

Thermal-structural coupling analysis of pouch power lithium-ion battery for electrical vehicles

建立了方形锂电池瞬态产热模型,将软包锂电池简化为各向异性的叠层式复合材料,确定了模型中的热物性参数和力学参数;使用ANSYS软件,利用顺序热-结构耦合方式,模拟了电池瞬态温度场和热应力场分布。研究结果表明,电池中心区域温度较高,且受压应力,侧边温度较低,且受拉应力;电池各边出现应力集中,且最大Mises应力随放电电流增大而增大,随环境温度升高而减小;最大形变发生在电池高度方向两端,且随放电电流增大和环境温度升高而增大。

In this work, a transient heat-production model of square lithium-ion battery was established; pouch lithium-ion battery was simplified as anisotropic laminated composite material,the thermal properties and mechanical parameters were defined in this model. The transient temperature field and thermal stress field were simulated by using sequential thermal-structural coupling method and ANSYS software. Results show that the center of the battery presents a higher temperature and compressive stress, while the side regions present a lower temperature and tensile stress. At the same time, stress concentration occurs on every edge of battery, the maximum stress increases when discharging current increases, while decreases when ambient temperature increases.Furthermore, the maximum deformation appears at the top and bottom of the battery, which getting worse if discharging current increases or ambient temperature going higher.