Single-phase static immersion-cooled battery thermal management system with finned heat pipes

Effective thermal management is of critical importance to the performance and safety of lithium-ion batteries. However, research on small and medium-sized battery packs remains scarce. This paper proposes a new immersion cooling method. It combines finned heat pipes with a single-phase static immersion fluid, achieving optimal battery pack homogeneity in existing studies while outperforming the performance of conventional immersion cooling. The method is particularly suitable for energy storage batteries and small and medium-sized battery pack cooling applications. This paper presents a verification of the cooling performance of the cooling method through a combination of simulation analysis and experimental validation. The results demonstrate that the cooling method can enable small and medium-sized battery packs to meet the heat dissipation requirements of 3C or even higher discharge rate under natural convection conditions. In the active cooling scenario, when the battery pack is discharged at a 3C multiplier, the cooling scheme of 9 finned heat pipes can reduce the maximum temperature of the flow-submerged cooled battery pack by 6.4 °C and the maximum temperature difference between cells by 5.3 °C. Even when the battery is discharged at an extreme multiplication rate of 6C, the maximum temperature of the battery pack can be maintained at approximately 60 °C, with a maximum temperature difference between cells of around 15 °C. Based on the aforementioned simulation and experimental results, this paper also validates and analyses the main factors affecting the cooling effect of the method, namely the type of submerged liquid and the number of finned heat pipes.