Synergistic Enhancement of Phase Change Materials through Three-Dimensional Macropore Lamellar Structured MOF/EG Composite for Solar Energy Storage and Beyond

Abstract

Phase change materials (PCMs) have gained significant attention as thermal energy storage materials for reducing dependence on fossil fuels. However, the leakage caused by long-term molecular motion has become a bottleneck for the further advances of energy storage density and application value. Herein, a novel PCM composite with good shape stability, thermal conductivity and photothermal conversion capability was designed. Given the synergistic or hybridization effect between metal-organic frameworks (MOFs) and expanded graphite (EG) components offered the composite unique capabilities, even with the merits of both. The combination of ZIF-67 and EG in a hybrid structure can effectively prevent particle agglomeration, while simultaneously providing a high specific surface area and pore volume for the adsorption of paraffin wax. Compared to pristine unsupported PCMs, the as-obtained PCM composite possesses a 3-fold enhancement in thermal conductivity, 95.56% photothermal conversion efficiency and excellent shape stability. It demonstrates the potential of MOFs-enhanced PCM composites for thermal energy storage and highlight the importance of synergistic or hybridization strategies in the development of advanced materials for sustainable energy applications.