Bio-Based Phase Change Material for Electric Vehicle Battery Thermal Management using Copper Fins: A Numerical Investigation

Electric vehicles (EVs) are gaining popularity due to their zero tailpipe emissions, superior energy efficiency, and sustainable nature. EVs have various limitations, and crucial one is the occurrence of thermal runaway in the battery pack. During charging or discharging condition of battery pack may result in thermal runaway condition. This promotes the requirement of effective cooling arrangement in and around the battery pack to avoid localized peak temperature. In the present work, thermal management of a 26650 Lithium iron phosphate (LFP) cell using natural convection air cooling, composite biobased phase change material (CBPCM) and its combination with copper fins is numerically investigated using multi-scale multi dimension - Newman, Tiedenann, Gu and Kim (MSMD-NTGK) battery model in Ansys Fluent at an ambient temperature of 306 K. Natural convection air cooling was found effective at discharge rates of 1C to 3C, maintaining cell temperature below the safe limit of 318 K for 80% DoD. However, the temperatures increased to 321.7 K and 325.4 K for 4C and 5C discharge rates respectively which indicating the inadequacy of natural convection air cooling for high-powered electric vehicles. 4 mm thick layer of CBPCM reduced the average cell surface temperatures to 312.7 K and 314.8 K for 4C and 5C discharge rates, respectively, while the integration of fins further reduced the temperatures to 310.7 K and 311.5 K. This reduction is due to the enhanced latent heat absorption of CBPCM and improved thermal conductivity provided by the fins. Overall, CBPCM combined with fins proved to be a more effective thermal management strategy than natural convection air cooling and standalone CBPCM.