Graphene hybrids for supercapacitor applications

Abstract

The most intriguing 2D form of carbon, graphene, is composed of a thin layer of tightly spaced carbon atoms. Since its discovery, graphene has fascinated researchers owing to its distinct electrical, chemical, and mechanical properties and large surface area. Graphene is the most efficient electrode material for supercapacitor applications because of its distinctive properties. However, the efficiency of graphene-based supercapacitors is severely hampered by the constant re-stacking between the carbon layers in graphene due to the strong van der Waals contacts between them. Moreover, they lag behind in providing the high energy density desired for supercapacitors. As a result, several techniques have been employed to avoid the issues outlined above. Graphene-based nanomaterials have been employed to overcome the above-mentioned limitations and significantly improve the efficiency of supercapacitors. Furthermore, graphene has been combined with other materials to boost the energy density of devices. Graphene-based hybrids have significantly increased supercapacitor performance when used as electrodes. Thus, focusing on their synthetic methodologies, topologies, and electrochemical characteristics for supercapacitor application, this study highlights the progress to date in graphene-based nanohybrids composed of metal oxides, chalcogenides, nitrides, carbides, phosphides, and conducting polymers. Furthermore, we discuss new approaches to augment the performance of next-generation supercapacitors.