Investigation on heat transfer enhancement of phase change material for battery thermal energy storage system based on composite triply periodic minimal surface

Phase change material (PCM), such as paraffin wax, has attracted extensive attention in the field of battery thermal energy storage (BTES) system. However, the latent heat of the PCM is unable to be efficiently utilized in the cases with fast thermal responses due to the low thermal conductivity. Triply periodic minimal surface (TPMS) has large surface area. In this study, the composite P-IWP type TPMS is proposed to enhance local heat transfer of the PCM. The thermal performance of the TPMS-based BTES system is studied by simulations and experiments. The results demonstrate that the composite P-IWP type TPMS sheet structure improves the efficiency of the PCM latent heat utilization. The enhanced heat transfer method based on traditional Kelvin type metal foam structure cannot make full use of the latent heat of PCM. Compared with the P type TPMS, the melting time of the PCM in the case of P-IWP type TPMS reduces by 30.8 %. The battery temperature in the case of P-IWP types TPMS decreases by 12.2 % and 11.3 % than that in the case of PCM-only at 1C and 2C discharge rates, respectively. In addition, the experimental results of the cycle process indicate that the TPMS-based BTES system reduces the temperature rise of the battery and increases the duration of the unit temperature drop. •A novel composite P-IWP type TPMS sheet structure is proposed.•The thermal energy storage property of the PCM is improved by the composite P-IWP type TPMS sheet structure.•The melting time of the PCM is reduced due to the local heat transfer enhancement.•The TPMS-based BTES system reduces the temperature rise and improves heat preservation performance of the battery.