Nitrogen and sulfur co-doped graphene aerogel with hierarchically porous structure for high-performance supercapacitors

Abstract

Supercapacitors with unique performance have been widely utilized in many fields. Herein, we report a nitrogen and sulfur co-doped graphene aerogel (N/S-GA-2) prepared using a low toxic precursor for high-performance supercapacitors. The as-obtained material possesses a hierarchically porous structure and a large number of electrochemical active sites. At a current density of 1 A g−1, the specific capacitance of the N/S-GA-2 for supercapacitors with the ionic liquid as the electrolyte is 169.4 F g−1, and the corresponding energy density is 84.5 Wh kg−1. At a power density of 8.9 kW kg−1, the energy density can reach up to 75.7 Wh kg−1, showing that the N/S-GA-2 has an excellent electrochemical performance. Consequently, the N/S-GA-2 can be used as a promising candidate of electrode materials for supercapacitors with high power density and high energy density. Keywords: Graphene aerogel, Hierarchically porous structure, Supercapacitor, Ionic liquid