Graphite-Mediated Microwave-Exfoliated Graphene Fluoride as Supercapacitor Electrodes

A graphite-mediated microwave-based strategy was used for solid-state exfoliation of graphite fluoride in a few seconds, followed by a simple yet efficient separation to obtain exfoliated materials based on the density difference between graphite and graphene fluoride in solvent. The microwave-exfoliated graphene fluoride was a few layers thick and electrically conductive. The electrochemical testing of pouch-cell supercapacitors assembled by using the exfoliated graphene fluoride electrodes and a novel microemulsion-based electrolyte showed reasonable performance with typical electrical double-layer capacitance behavior and good rate capability (gravimetric specific capacitance: 3.2 F g^-1 at 500 mA g^-1 and 3.1 F g^-1 at 5000 mA g^-1). The BET specific surface areas of the as-exfoliated graphene fluoride are ~60-80 m² g^-1, which could be increased by activation using this simple yet versatile microwave-based method for further improvements on the electrochemical performance.