快充条件下18650锂离子电池热-力耦合分析

为研究锂离子电池温升所产生的热应力和形变分布,建立了快充条件下18650锂离子电池的热模型,仿真得到不同环境温度下电池的温度场分布,并在此基础上建立顺序热-力耦合模型,进一步分析电池的热应力和形变分布.结果表明:随着环境温度增加,电池最高温度增大,温差减小,充电末期电池温度稍有下降且降幅随环境温度增加而减小;最大应力值出现在电池柱面外边中间部分,最小应力分布在轴向两端;最大形变分布在电池轴向两端,最小形变出现在电池中心区域;电池的应力和形变随环境温度增加分别呈减小和增大趋势.

Thermal-mechanical coupling analysis of 18650 Li-ion battery under fast charging condition

In order to study the thermal stress and deformation distribution generated by the temperature rise of Li-ion batteries, the thermal model of 18650 Li-ion battery under the condition of fast charging was established, and the temperature field distribution of 18650 Li-ion battery under different ambient temperature was simulated. On this basis, a sequential thermo-mechanical coupling model was established to further analyze the distribution of thermal stress and total deformation of the battery. The results show that with the increase of ambient temperature, the maximum temperature of the battery increases, the temperature difference decreases. The battery temperature drops slightly at the end of charging, and the drop decreases with the increase of ambient temperature. The maximum stress value appears in the middle of the outer edge of the battery cylinder, and the minimum stress is distributed at both ends of the axial direction of the battery. The maximum deformation is distributed at both ends of the axial direction of the battery, and the minimum deformation is located in the central area of the battery. The stress and total deformation of the battery respectively decrease and increase with the increase of ambient temperature.