Effect of graphite powder on thermal behavior of phase change material

The effect of graphite powder on the thermal behavior of phase change material (PCM) was investigated experimentally. It is well known that the graphite is contributed to enhance the thermal response. However, the effect of graphite on the supercooling of the PCM is not clear when a highly heat conductive material is added. In this study, the specific heat of the PCM based on sugar alcohol such as D-mannitol and inositol was measured with an adiabatic scanning calorimeter. The enthalpy and entropy during the phase-change process were obtained by the measured specific heat of the PCM. Additionally, the exergy analysis was conducted to evaluate the thermal energy storage of PCM. As the experimental results, the specific heat of D-mannitol during the phase change process was higher than that of inositol. Moreover, it was found that the addition of graphite powder at the mass fraction of 9% improves the thermal behavior of D-mannitol with lower supercooling while maintaining latent heat. The suppression of supercooling by the addition of 9% graphite powder was 37.5%.