Abstract This study presents a high-fidelity transient numerical analysis of hybrid passive Battery Thermal Management Systems (BTMS) integrating Phase Change Material (PCM), Heat Pipes (HP), and aluminium fins for effective heat mitigation in lithium-ion batteries subjected to high discharge rates. Three configurations PCM-only, PCM + HP, and PCM + HP + Fin were evaluated at 2C, 3C, and 4C discharge rates under varying convective heat transfer coefficients (h = 15, 30, and 60 W/m2·K). Unlike existing passive cooling approaches, this work uniquely combines axial heat pipe conduction, latent heat absorption from PCM, and fin-assisted lateral dispersion to form a synergistic passive thermal control system. The PCM-only system exhibited poor performance at 4C, with Tmax reaching 318.2 K and LF rising to 0.53, indicating substantial PCM melting and inadequate thermal buffering. The PCM + HP configuration improved Tmax to 316.4 K and reduced LF to 0.50 under identical conditions. At 2C and h = 60 W/m2·K, the same configuration-maintained Tmax at 308.49 K with zero PCM melting. Temperature difference (ΔT) across the battery pack was minimized to less than 1.0 K, confirming excellent thermal uniformity. Validation against literature results yielded a deviation of less than 1.5 K, verifying the model's accuracy. The combined effects of axial conduction via HPs, surface area enhancement through fins, and latent heat buffering by PCM demonstrate a highly synergistic mechanism.
Shehabaz et al. (Wed,) studied this question.