Numerical Evaluation of Thermal Cooling in 32700 Lithium-Ion Cell-Based Electric Two-Wheeler Battery Pack

Abstract

As the electric vehicle have become reality in today’s world of technology advancement, lithium-ion cells are the main reason to achieve this paradigm shift. Lithium-ion cells properties have enhanced energy density, cycle life, and safety, making it suitable for electric vehicle utilization. The main disadvantage of these cells is that when run at high C-rate, the cell temperature increases. In order to maintain the cells healthy for a longer time frame and to prevent thermal runaway, the cells must be kept at their optimal operating temperature. Presently, no separate battery pack thermal management system is used in the two-wheeler electric vehicle. As a result, this study makes an earnest endeavor to provide a solution for battery pack temperature control employing phase change material (PCM).  In this case, an entire battery pack of a two-wheeler electric vehicle is studied, and work is done on building a battery pack casing, 32700 lithium-ion cells, and PCM based thermal cooling system. A battery architecture of 20P16S (320 cells) with LFP 32700 cell is chosen for the pack, while paraffin wax with graphene nanoparticles mixture is selected as the cooling medium for cells. The designed top cover plate can withstand weight over 80kg with less than 0.1mm total deformation for steel and aluminum material. The passive cooling solution provides better cooling of battery pack in comparison to natural air cooling.