Uniform temperature distribution, prolonged temperature regulation, and accelerated recovery of battery thermal management system using a novel fin design

This study proposed a battery thermal management system (BTMS) integrating phase change material (PCM) with novel interior-exterior fins to address the low heat conduction properties of PCM. The battery heat generation and PCM liquefaction were analysed using the lumped model and enthalpy-porosity technique. The irreversible, reversible, and total battery heat generation were investigated. The BTMS was investigated under 1C, 2C, 3C, and 5C current rates. The Interior-Exterior Fin-PCM-Air-Cooled BTMS outperformed the Air-Cooled BTMS, PCM-Air-Cooled BTMS, Interior Fin-PCM-Air-Cooled BTMS, and Exterior Fin-PCM-Air-Cooled BTMS before, during, and after the PCM melting process, providing a superior uniform cooling effect to the battery. Different heat transfer mechanisms were identified throughout the PCM phase transition. During PCM melting and solidification cycles at 5C, the variation in the maximum battery surface temperature in the Interior-Exterior Fin-PCM-Air-Cooled BTMS was 15.98 K lower than that in the PCM-Air-Cooled BTMS, buffering the effects of the temperature change. In the first cycle at 5C, the interior-exterior fins extended the duration for which the battery's temperature remained within the optimal range by 6.91 % and decreased the recovery period of the thermal management system by 37.56 % compared to the PCM-Air-Cooled BTMS. These results provided new horizons for the development of effective BTMSs. • Interior-exterior fins were more effective than interior fins for PCM-based BTMSs. • Conduction and convection heat transfer were observed during PCM melting process. • The BTMS with interior-exterior fins provided temperature-buffering effect. • Interior-exterior fins prolonged the period for optimum battery temperature. • Interior-exterior fins decreased the recovery period of the PCM-based BTMS.