Thermal conductivity of phase change materials in solid state at high temperature

The portfolio of phase change material (PCM) candidates available for high temperature applications that are fully characterized in the solid-phase within these elevated temperature ranges is limited. In this study, 11 PCM candidates—previously proposed for high-temperature applications—were experimentally characterized in terms of solid-phase thermal conductivity at both room (20 °C) and high temperature (300 °C). The results revealed a substantial and general decrease in solid-phase thermal conductivity with increasing temperature, highlighting the importance of conducting thermal characterization at high temperature. These PCM candidates were subsequently compared with the few PCMs reported in the literature for similar applications and characterized within the same temperature ranges, by considering the solid-phase thermal conductivity analyzed in study, as well as the melting temperature and latent heat obtained from a previous study. Thanks to this, a comprehensive comparative map of PCM candidates fully characterized in the solid state at high temperature was finally presented (≥300 °C).