PCM-based passive cooling solution for Li-ion battery pack, a theoretical and numerical study

We propose in this study a novel cooling solution for Li-ion battery packs based on Phase Change Materials (PCM) and metallic fins placed around each cell. Discharging and charging processes both melt the PCM. To complete the thermal management of the batteries, an intermediary sequence is added for the PCM solidification. During a short timeframe between batteries charging and discharging, a liquid coolant flows through one small channel located within each fin. A numerical model and a theoretical analysis allow to predict the thermal behavior of the battery cells and the PCM liquid fraction changes in time. It is shown that the combination of a passive cooling solution brought by the PCM with the fast period of liquid cooling for the PCM solidification is an effective solution to control the temperature evolution within the battery cells during discharge and charge. The only external energy consumption foreseen comes from the laminar flow of the coolant for solidification during a very short period of time. The findings indicate that the proposed PCM-liquid cooling integration reduces the total energy consumption by 54.9 % (from 0.4406 kJ to 0.1963 kJ) for the 2C discharging-2C charging cycle compared to traditional liquid-cooling strategy.