Appropriate Proportion of Holey Graphene Used as Partial Conductive Agent in Electric Double-Layer Supercapacitors

Graphene is widely used in supercapacitors as active materials and conductive agents because of its large specific surface area, high electrical conductivity and electron mobility. However, there are few studies on microwave treatment of graphene for perforating and using holey graphene mixed with conductive carbon black as conductive agent. Here, we report the best mixing ratio of holey graphene and conductive carbon black treated by microwave, that is, 5%SP + 5%HG has good electrochemical comprehensive properties. We attribute the improved performance to the fact that the holey graphene can reduce the migration distance between the electrode and the electrolyte because of pores. At the same time, the larger specific surface area of graphene can be connected with conductive carbon black, thus improving the comprehensive performance of electric double layer capacitors. Compared with only using graphene as conductive agent, this method reduces the overall cost and is more suitable for industrial application.