CFD Analysis of Liquid Cold Plates for Efficient Thermal Performance of Electric Vehicle Li-Ion Battery Modules

Abstract

Immersion cooling for an EV battery module using NCA-chemistry based cylindrical 21700 format Lithium-ion cells is evaluated in this work. A cold-plate-cooled battery module is compared to an immersion-cooled battery module in terms of maximum cell temperature, cell temperature gradient, cell-to-cell temperature difference, and pressure drop. Coolant flow rates and module discharge C-rates are analyzed in order to determine how each cooling technique affects crucial system performance factors. Computational Fluid Dynamics (3D time-accurate) is used for the full numerical analysis (CFD). A lower maximum cell temperature and smaller temperature gradients inside the cells are seen when using immersion cooling, which is likely owing to the cooler's increased thermal conductivity. Due to weak thermal characteristics and a higher rate of heat rejection, there is a substantially greater temperature variation throughout the module. The thermal performance of the two cooling systems is comparable at lower discharge rates. Additionally, an immersion-cooled battery module has greater performance due to the decreased density and viscosity of the dielectric liquid.