Numerical and Experimental Investigation on Enhancing Thermal Conductivity of Paraffin Wax with Expanded Graphene in Battery Thermal Management System

Battery Thermal Management System using phase change materials has gained its popularity due to its passive nature. Paraffin is considered a widely used phase change material but limited its applications due to its low thermal conductivity. In this present work to increase the thermal conductivity of paraffin, expanded graphite is added to the battery module at various ratios (0.5%, 1%, 1.5% and 2%). Computational analysis is conducted to study the temperature distribution of PCM/EG composites-based battery thermal management system at various ambient temperatures (25 °C, 40 °C and 55 °C). To increase the thermal conductivity of the module further copper tubes were inserted inside the horizontal pocket structure and analysis was carried out. Finally, the experimental studies are conducted by fabricating the PCM/EG composites battery module and it is well matched with the simulation studies. Results obtained concludes that PCM/EG with 2% expanded graphite along with copper tubes performs well at all ambient conditions. A maximum of around 7 °C reductions in temperature is obtained after implementing copper tubes at 25 °C and 40 °C operating conditions. This shows clearly that the designed PCM/EG composites model performs well at ambient and medium temperature operating conditions. Experimental studies result also reveals that a maximum of around 38 °C is obtained while operating battery modules for several hours at 2C discharge rate conditions.