Erythritol/expanded graphite form-stable phase change materials with excellent thermophysical properties

Organic phase change materials possess the merits of high latent heat storage, small temperature changes, high chemical/thermal stability, low corrosion and reusability, and thus have attracted extensive attention in the research of low and medium-temperature energy storage media. However, pure phase change material has the deficiency of low thermal conductivity and easy leakiness, which seriously hinder their practical large-scale applications. In this work, the expanded graphite was used as the skeleton to encapsulate erythritol to form the composite phase change material. The composite had remarkably boosted thermal conductivity (5.97 ± 0.30 W/m·K compared with pure erythritol of 0.60 ± 0.03 W/m·K) and high melting latent heat (290.52 J/g) and solidification latent heat (239.52 J/g) at a loading rate of 95 wt%. The supercooling degree was reduced from 92.41 °C to 43.75 °C, facilitating the release of latent heat. The developed composite phase change material exhibits extraordinary heat transfer and storage characteristics, which has great application prospects in the fields of solar photothermal conversion utilization.