An Analytical 2D Formulation for the Combined Cooling of PCM-Covered Cylindrical Battery Cells

Abstract

Lithium-ion battery packs are being used more and more in high energy, high power applications such as in power devices, drones, and electric or unmanned vehicles. Battery packs require careful heat management to guarantee near-optimal and safe, hazard-free operation. Modern heat management systems include combined air–phase change material (PCM) strategies, the accurate analysis and simulation of which lead to FEM/computational fluid dynamics (CFD) modeling, as is often seen in the literature. In this study, we developed an analytical two-dimensional (2D) formulation for an air–PCM cooling system installed around a cylindrical cell. This approximate formulation enabled us to rapidly investigate the effects of the airflow field and PCM thickness at multiple operating conditions and to estimate the overall thermal resistance and melted volume of PCM. The results were benchmarked with FEM simulations and then compared with the literature. A comprehensive investigation of the airflow effects under various temperature and current rates is presented and discussed in detail. The analytical formulation in this work can be easily programmed and used in fast estimations of performance or for design purposes.