Topology optimization of air-cooled battery thermal management systems for uniform temperature distribution in lithium-ion battery modules

Abstract

This study developed a new topology optimization approach using a milling constraint and curve fitting in fluid dynamics and optimized U- and Z-type BTMSs for flowrate and temperature distribution uniformity in the lithium-ion battery module. This topology optimization procedure begins from the external surface to reduce viscous power dissipation and deviation of flow rate and has an easier manufacturing process than the traditional topology optimization. In this study, the deviation in the flow rate, which was a 10% fixed constraint, decreased to 5.80% for the U-type BTMS and 3.51% for the Z-type BTMS. Compared with the base model, the U- and Z-type optimized models reduced the deviation of the flow rate from 47.9% and 58.6% to 6.24% and 4.47%, respectively, the deviation of the average temperature decreased by 2.83% and 3.38% to 0.69% and 0.36%, respectively, and the maximum temperature difference decreased from 3.46 and 4.06 °C to 0.88 and 0.45 °C, respectively. In engineering, the weight and power consumption are some of the figures of merit. Hence, the weights of the U- and Z-type optimized models were reduced by 41.6% and 25.9%, respectively, and the power consumption were reduced by 68.0% and 67.8%, respectively. Furthermore, numerical simulations with various Reynolds numbers confirmed that the optimal Reynolds numbers for the U-type and Z-type topology-optimized models are 1713 and 1677, respectively. These findings indicate that the proposed topology optimized BTMS designs effectively mitigate aging, degradation, and thermal runaway risks due to large temperature differences between lithium-ion battery cells.