Effect of cooling air inlet angle on thermal management of lithium-ion battery modules with flow-controlled baffles

Abstract

The battery thermal management system plays an important role in controlling temperature to ensure safe and stable battery operation. In this study, a traditional Z-flow airflow pattern was applied to a 4 × 6 lithium-ion battery module consisting of cylindrical 18650 cells. The effect of varying the cooling air inlet angle was investigated using computational fluid dynamics simulations to evaluate thermal performance. The results show that changing the inlet angle to 120° provides the most uniform cooling, with the maximum temperature and maximum temperature difference reduced by 5.03 K and 5.09 K, respectively, compared to the original Z-flow model. However, airflow distribution remained insufficient in regions farther from the inlet. To overcome this limitation, an improved design incorporating flow-control baffles and a redesigned outlet configuration was proposed. The optimized model further reduced the maximum module temperature to 308.50 K and the maximum temperature difference to 2.97 K. Although the pressure drop increased from 20.71 Pa to 31.65 Pa, the enhanced airflow circulation significantly improved temperature uniformity and cooling effectiveness. These results are based on CFD simulations under the specified operating conditions and are therefore limited to the investigated battery module configuration and airflow conditions. Future experimental validation is recommended to verify the practical applicability of the proposed design.