Thermal conductivity enhancement and thermal saturation elimination designs of battery thermal management system for phase change materials based on triply periodic minimal surface

Phase change material (PCM) exhibits great application prospects for battery thermal management system (BTMS) due to their high enthalpy of phase change. However, the low thermal conductivity of PCM has limited its application in fast thermal response. Furthermore, the risk of battery thermal runaway will be exacerbated by the thermal saturation of PCM after complete melting. In this study, triply periodic minimal surface (TPMS) sheet structure is proposed for thermal conductivity enhancement and thermal saturation elimination of PCM. The thermal performance of the BTMS is studied by simulations and experiments. The results show that the TPMS sheet structure improves the heat transfer performance and decreases the battery temperature at 1C discharge rate. When the PCM is combined with the liquid cooling, the average battery temperature of the PCM/liquid/TPMS-based BTMS is 40% lower than that of the PCM/TPMS-based BTMS at 2C discharge rate, eliminating the thermal saturation of PCM. At 1C discharge rate, the phase transition temperature of PCM can affect the cooling performance of the BTMS without liquid cooling. For the PCM/TPMS-based BTMS, at 1C discharge rate, the average battery temperature with phase transition temperature of PCM at 35 °C is 8.5% lower than that at 40 °C.