Numerical investigation of a vapor chamber-assisted liquid cooling system for cylindrical battery thermal management

Abstract An efficient battery thermal management system (BTMS) is critical for ensuring performance and lifespan of the battery module. To enhance the module thermal performance, a new liquid cooling system integrating with vapor chambers for cylindrical battery module is proposed in this paper. Systematically numerical studies are carried out to compare performance of three BTMSs: liquid cooling (LC), liquid cooling with vapor chamber (LC-VC), and liquid cooling with two-end vapor chambers (LC-2VCs). Results highlight that integrating VC reduces the maximum temperature of the battery module (Tmax) and shows preferable temperature distribution. It is detected that LC-VC displays excellent temperature uniformity performance along coolant flow path with the maximum temperature difference (ΔTmax) of 6.65 K at 3C discharge rate compared to the LC case with ΔTmax of 9.18 K. However, it still suffers from a noticeable temperature gradient from the top to the bottom thermal transfer paths. In contrast, LC-2VCs further enhances the temperature uniformity with ΔTmax of 4.72 K and controls Tmax of 306.89 K. Then, effects of the battery axial thermal conductivity, VC effective thermal conductivity, fin height, inlet velocity on cooling performance of LC-VC and LC-2VCs are examined. Finally, the cooling performance under optimal conditions is compared to initial conditions. The results show that Tmax and ΔTmax for LC-2VCs are controlled at 305.58 K and 3.51 K under 3C discharge rate, reducing by 1.31 K and 1.21 K, respectively, compared to initial conditions.