Efficient thermal management of Lithium-ion (Li-ion) battery packs is critical to ensure safety, performance, and longevity in electric vehicles (EVs). This study investigates the influence of cell and module arrangements on the thermal behaviour and pumping power of cylindrical Li-ion battery packs using full immersion liquid cooling. A numerical model of a battery pack comprising 3072 cells arranged in 16 modules is developed to systematically evaluate the effects of cell orientation, inter-cell spacing, inlet/outlet distances, and module configurations under various operating conditions. After obtaining the best cell arrangement in the module, five different module arrangements (e.g., 16S, 4S4P, 2S8P, 16P) are evaluated based on mean and maximum temperatures, temperature gradients and pressure drop. Results indicate that a 30° cell orientation combined with a 2 mm spacing provides an optimal balance between thermal performance and compact design. Among the module configurations, the 2S8P arrangement achieves a maximum temperature of 32.8 °C, a temperature gradient of 7.3 °C, and a moderate pressure drop of approximately 21.2 kPa. Furthermore, reducing coolant temperature difference improves thermal uniformity but increases pumping power requirements. Compared to existing studies that typically consider isolated parameters, this work provides a comprehensive parametric framework that integrates both cell- and module-level design variables. The proposed design provides practical design guidelines for optimizing thermal performance while maintaining acceptable pressure losses, supporting the development of safer and more efficient battery packs for electric vehicle applications. • 30° cell angle offers optimal thermal and space efficiency. • 2 mm cell spacing balances cooling and fluid volume. • 2S8P module layout gives best performance and low pressure drop. • Lower coolant temps improve cooling but raise pumping power. • Higher charging rates demand more flow, raising pressure losses.
Talebizadehsardari et al. (Fri,) studied this question.