Graphene and relative materials
Due to the significant advantages of high power density, high rate capacity and long cycling life, supercapacitors play an important role ranging from portable electronics to hybrid electric vehicles, and other high power energy sources. Recently, graphene and their composites, due to their unique mechanical strength, chemical stability, high conductivity and theoretical specific surface area as well as low fabrication cost, has emerged an ideal candidates for electrochemical energy storage devices. Because of the aggregating nature of graphene due to strong π–π interactions, the large surface area cannot be fully utilized, especially at a high charge- discharge rate. To overcome the overstacking problems of graphene sheets and obtain high rate performance and high ionic and electronic transport kinetics in supercapacitors, various three-dimensional (3D) graphene bulk materials have been developed and they were called graphene aerogels (GA). Generally, GA is a structure which contains interconnected pores that prevent the restacking of graphene sheets.