Optimization of gravity heat pipe-air hybrid thermal management system for power batteries in high-rate scenarios

Abstract This paper proposes a gravity heat pipe-air hybrid temperature control system to address the inadequate heat dissipation in power batteries under high-rate discharge conditions when using single cooling methods. The system’s performance was evaluated for series-arranged battery packs at discharge rates above 5C. Results show that the system effectively meets thermal management requirements for 3-cell packs at 5C, but as the number of cells increases to seven, temperature control degrades, with temperature uniformity exceeding the 5 °C threshold, leading to system failure. To resolve this, a “C-shaped” configuration was adopted for improved battery pack arrangement. Further analysis demonstrates that the optimized system effectively manages heat dissipation for discharge rates up to 7C within a cooling air temperature span of 20 °C to 35 °C.