Temperature Simulation and Analysis of Power Lithium-ion Battery Module Based on Two-dimensional CFD Thermal Model

Abstract

The power lithium battery generates a lot of heat during working, whose heat dissipation performance will directly affect its working performance and safety. In order to study the heat dissipation characteristics of lithium batteries, In this paper, a battery module structure based on phase change material(PCM) was designed, and a two-dimensional battery heat generation model and a heat transfer model based on PCMs were established. Then, the geometric model, grid division and grid size correlation verification were carried out using ANSYS simulation software. Under comprehensive consideration of computational efficiency and accuracy, 0.5mm was selected as the grid division size. Finally, for the charging and discharge cycle, the temperature field of the battery module based on composite phase change material(CPCM) composed of pure graphite material and expanded graphite, and paraffin is simulated respectively. At the same time, the influence of ambient temperature on the heat dissipation performance of battery module with PCM was studied. when the ambient temperature is set to be 17°C, 27 °C and 37 °C respectively, the maximum temperature of the battery module base on PCM is 199°C, 211°C and 223°C respectively, and the maximum temperature difference is 162°C, 164°C and 165 °C respectively. The results show that the heat dissipation performance of the battery module with CPCM is better than that of PCM under cycle conditions. What’s more, the higher the ambient temperature is, the higher the temperature of the battery module is. The research results in this paper can provide a certain reference for the thermal management design of the battery.