Construction of high thermal conductivity MOFs composite phase change materials with reinforced light-to-thermal conversion

Abstract

Improving the light-to-thermal conversion properties of phase change materials (PCMs) is conducive to the development of their applications in solar thermal energy storage systems. In this work, a porous structure of expanded graphite (EG) modified Ni-MOF was synthesized by hydrothermal synthesis, and scattered in CH 3 COONa‧3H 2 O (SAT) by a physical blending and impregnation method to obtain a novel composite phase change material with reinforce light-to-thermal conversion. The resulting composite PCM showed that the latent heat of composite PCM was 166.6J/g, the supercooling temperature was reduced to 2.5 °C. The porous network structure formed by the close combination of EG and MOF effectively enhanced the heat transfer rate of composite PCM. The thermal conductivity of composite PCM was about 3.21 times that of pure SAT. Furthermore, the composite PCM showed good thermal cycling performance and excellent light-to-thermal conversion properties, which could be suggested as a promising candidate for solar thermal storage systems. • Porous structure of EG@Ni-MOF is synthesized via hydrothermal synthesis method. • The existence of EG@Ni-MOF reinforces the light-to-thermal conversion. • The composite PCM exhibits improved thermal conductivity. • This work provides a new approach for the utilization of solar energy.