A Systematic Approach to Evaluation of Various Cooling Strategies for EV Battery Pack Prismatic Cell using Analytical and Numerical Methods

Abstract

Technology to maximize energy density and life of Lithium-ion batteries at a gradually reducing cost is evolving day by day. Fast charging of the battery pack has become one of the major requirements of electric vehicles. Such a requirement invariably poses certain challenges to the cells of the EV battery pack. One of them is to achieve an efficient and an optimal thermal management of the battery pack to maintain uniform operating temperature of the cells and within the manufacturers’ allowable range to ultimately increase the lifespan and reliability of the battery pack. The current work discusses the design strategies of cell cooling, heat load estimation & features of different cooling strategies. A MS Excel spreadsheet-based design tool was developed to quickly estimate the cell temperature gradient. The results from the spreadsheet-based tool, which was based on fundamental equations, correlated well with 3D CFD simulation results. The results were analysed and the cooling strategy for the battery pack was decided based on the analytical and numerical values obtained from the analysis of various cell parameters. 

Keywords: Thermal management; Design strategies of cell cooling; Heat load estimation; Spread sheet; Temperature gradient; 3D CFD simulation