Graphene a promising electrode material for supercapacitors-A review

Abstract

The global demand for high performance and environmentally friendly energy storage systems leads to intensive research on new and advanced electrode materials that are able to satisfy the fast-growing global market in various applications. The 2D graphene material is one of the most promising candidates for next-generation energy storage applications, particularly supercapacitor devices due to its exceptional intrinsic properties such as highest theoretical specific surface area (2600 m2/g), high electrical charges mobility (230 000 cm2/V·s), thermal conductivity (3000 W/mK), and highest strength (130 GPa). This comprehensive review summarizes the most recent progress made on the graphene material in its different structural forms of foams (3D), thin films (2D), nano-fibers (1D), and nano-dotes (0D) for supercapacitor electrodes. It initiates with a brief historical introduction on graphene discovery and its current production techniques that retain its intrinsic properties ranging from mechanical exfoliation of graphene in high quality to its epitaxial growth by chemical vapor deposition on metal substrates and its derivation by chemical reduction of graphene oxide. In addition to highlighting its main characterization techniques such as Raman spectroscopy, atomic force microscopy, and transmission electron microscopy, as well as, its critical properties including electrical, optical, mechanical, and thermal properties. Its potential applications are also illustrated with emphasizing on its usage as an electrode material in supercapacitors. Finally, its main challenges and future prospects are considerably pointed out.