Impact of thermal management on the performance of the series-parallel battery pack

Lithium-ion battery packs, configured in series and parallel connections, are widely utilized in electric vehicles to meet high-capacity and high-power demands. However, under fixed interconnect resistances and current collector configurations, thermal management significantly influences pack performance. This study develops an electrochemical-thermal coupling model validated through multi-rate discharge experiments. A battery pack comprising 24 cells with series-parallel connections is constructed, incorporating interconnect resistances and collector positions. Simulations investigate the effects of thermal management strategies on electrical and thermal behavior. Results indicate that edge modules directly linked to current collectors exhibit the poorest current uniformity. Negative temperature gradients induced by thermal management toward collectors improve current consistency, while minimizing internal temperature differences enhances overall performance. To extend battery lifespan, optimized thermal management designs must account for interconnect resistances and collector layouts to achieve balanced operational performance.