Self-standing rationally functionalized graphene as high-performance electrode materials for supercapacitors

Supercapacitors (SCs) have attracted much attention as one of the alternative energy devices due to their high power performance, long cycle life, and low maintenance cost. Graphene is considered as an innovative and promising material due to its large theoretical specific surface area, high electrical conductivity, good mechanical properties and chemical stability. Herein, we report an effective strategy for elaborately constructing rationally functionalized self-standing graphene (SG) obtained from giant graphene oxide (GGO) paper followed by an ultrarapid thermal-processing. This treatment results in both the exfoliation of graphene sheets and the reduction of GGO by elimination of oxygen-containing groups. The as-prepared SG electrode materials without additive and conducting agent provide an excellent combination of the electrical double layer capacitor (EDLC) and pseudocapacitor (PC) functions and exhibit superior electrochemical performance, including high specific capacitance, good rate capability and excellent cycling stability when investigated in three-electrode electrochemical cells.