Numerical analysis and surrogate model optimization of air-cooled battery modules using double-layer heat spreading plates

In this paper, the air-cooled battery module with thermally conductive heat spreading plate (HSP) is investigated numerically and optimized using the surrogate models to enhance the air cooling capability. In the battery module, the cylindrical batteries are arranged in a 4 × 5 aligned array. The HSP is allocated to the middle of the batteries, acting as not only the enlarged surface but also heat homogenizer due to the reversed heat flow effect. The numerical modeling is first validated with experimental data and then applied to examine the thermal performance of both single-layer and double-layer HSPs at the discharge rate of 3C. Multi-objective optimization of the double-layer HSPs case is conducted to further improve the thermal performance of the battery module. The optimizing parameters include HSP thickness, length of sleeve tube, downstream length of HSP and spacing of the adjacent battery cells. The temperature rise and temperature difference of the optimized battery module are decreased by 36.48% and 44.36%, respectively, which extends the cooling limit of battery module greatly at the minimal increase of 11.32% in the mass of the battery module. Further study on the effects of inlet velocity and fan power shows show that the temperature uniformity can be effectively maintained even with lower fan power.