Graphene in Supercapacitor Applications

The use of graphene-based materials for electrochemical double-layer capacitor (EDLCs) electrodes is reviewed. To establish a detailed understanding of the science and technology of graphene-based EDLCs, we summarize the key aspects of graphene-based materials, including specific surface area, pore size distribution, interlayer distance, heteroatom doping, surface functionalities, and conductivity. We also discuss the contribution of these physical-chemical properties to the capacitance and rate performance of graphene-based EDLCs. Although graphene is one of the most promising electrode materials for supercapacitors, many challenges still remain, particularly to establish a standardized measurement of capacitor performance, to reduce the price of graphene-based EDLC, to understand the mechanism of ion sorption on graphene, to study self-discharge mechanisms of graphene-based supercapacitors, to propose a new storage method for graphene-based EDLCs, etc. The full potential of graphene-based EDLCs as energy storage sources has not been fully developed, but as outlined in this review, the future looks very promising.