Effects of supercritical carbon dioxide cooling on heat dissipation performance enhancement of a prismatic LiFePO4 battery pack

In order to maintain the battery operation temperature within the appropriate range, an effective heat dissipation strategy should be developed. Generally, the air, water and phase change material (PCM) are adopted as cooling medium to remove heat from battery. However, these mediums have some performance limitations under the fast charging/discharging process of battery pack. The supercritical carbon dioxide (sCO2) has many desirable physical and transport properties near the critical point, and the leakage of CO2 will also not threaten the battery security. It is attractive to employ the sCO2 as cooling medium of the battery thermal management system (BTMS). Therefore, the numerical investigation on the heat dissipation performance of a BTMS featuring the serpentine channel cold plate using sCO2 as coolant is conducted in this work. The results indicate that compared with the water cooling, the sCO2 cooling could significantly reduce the battery temperature rise, temperature difference and power consumption since sCO2 has significantly higher specific heat capacity and lower viscosity, causing the far higher heat transfer coefficient and lower pressure loss. Moreover, the operation parameters of sCO2 cooling approaching to the critical or pseudo-critical point of sCO2 contribute to obtaining a better overall heat dissipation performance for battery.