Characterization of Expanded Graphite Microstructure and Fabrication of Composite Phase-Change Material for Energy Storage

Abstract

Phase-change composites for energy storage were prepared by the expanded graphite (EG) absorption method and their microstructures were analyzed. The organic phase-change materials (PCMs) were evaluated for their thermal and latent heat storage properties. The expanded graphite was prepared under the microwave irradiation. The scanning electron microscope (SEM) and mercury intrusion porosimetry analyses showed that expanded graphite had micron-size pores. The EG was able to easily absorb organic PCMs because of its nonpolarity and porosity. Composite PCMs for energy storage were fabricated with paraffin and the expanded graphite. The resulting material showed superior heat storage (releasing) effects and reduced large-range fluctuation in environmental temperature, thus achieving energy transfer simultaneously across different times and space.