Numerical investigation of air cooling system for a densely packed battery to enhance the cooling performance through cell arrangement strategy

Recent studies have revealed that the operating temperature and temperature uniformity within the battery pack significantly affected its performance. In this study, the air-cooled thermal management system of a densely packed battery pack was numerically investigated under different cell arrangements such as inline, offset, and staggered configurations to evaluate their cooling characteristics. The effects of inlet ambient air velocity and discharge rate were also evaluated to guarantee the temperature of the battery pack operated within an optimal range. The results revealed that increased airflow enhanced the cooling performance of the system but also increased the flow resistance, resulting in large power consumption. A battery pack operating at the low discharge rate of 0.5C might not require forced air-cooling. For fast discharge rates, especially over 2C-rate, forced air-cooling would not be economical for battery thermal management. A narrow cell-to-cell distance can decrease the cell temperature and also improve space utilization; however, it increased the power consumption for circulating air and the risk of a thermal runaway propagation. A trade-off between thermal dissipation and energy consumption was investigated. After comparing several circumstances, the offset layout was the appropriate choice for the air-cooled thermal management system, followed by the inline layout. It satisfied the requirements of low power consumption, high space utilization, and efficient cooling performance; in particular, the offset layout consumed about 43.1% less power than the inline layout, while losing space utilization of only 6.3%.