Evaluating Air-Cooling Performance of Lithium-Ion-Battery Module with Various Cell Arrangements

The significant heat generated during the operation of lithium-ion batteries raises the battery temperature thereby leading to performance degradation and thermal runaway in a thermal abuse environment. Therefore, a simple but effective battery thermal management system (BTMS) is crucial to achieve the permissible operating temperatures. In this work, the performance of air-cooled BTMS is evaluated by changing the arrangement of cells under discharging conditions. Seven distinct arrangements (trapezoidal, slanted, cross, aligned, staggered, tilted square, and zigzag) of lithium-ion cells are investigated in a rectangular battery pack. Two-way coupling of 1D electrochemical model and 2D conjugate thermal-fluid model is employed. The increasing Reynolds number reduces the cell temperature due to augmented convective effects. Under otherwise identical conditions, the zigzag cell arrangement outperforms the other cell arrangements but at the expense of the highest pressure drop (approximate to threefold). Particularly, the values of average and maximum cell temperature are reduced by approximate to 5K and approximate to 4K, respectively, for Re = 1000 at 1C in comparison to the aligned cell arrangement. Similarly, the least favorable performance is predicted by the trapezoidal, slanted, and cross-cell arrangements. Finally, a performance plot is suggested considering the trade-off between the power requirement and the cooling enhancement. The thermal and hydrodynamic impact of seven distinct cell arrangements on air-cooling performance of lithium-ion battery module at 1C and 5C discharge rates is evaluated. Typical results on pressure drop, cell average and maximum temperature, and Nusselt number are presented and thoroughly analyzed under the laminar flow conditions. Zigzag cell layout outperforms but at an expense of increased pressure drop.image (c) 2023 WILEY-VCH GmbH