Supercapacitors based on self-assembled graphene organogel

Abstract

Self-assembled graphene organogel (SGO) with 3-dimensional (3D) macrostructure was prepared by solvothermal reduction of a graphene oxide (GO) dispersion in propylene carbonate (PC). This SGO was used as an electrode material for fabricating supercapacitors with a PC electrolyte. The supercapacitor can be operated in a wide voltage range of 0–3 V and exhibits a high specific capacitance of 140 F g⁻¹ at a discharge current density of 1 A g⁻¹. Furthermore, it can still keep a specific capacitance of 90 F g⁻¹ at a high current density of 30 A g⁻¹. The maximum energy density of the SGO based supercapacitor was tested to be 43.5 Wh kg⁻¹, and this value is higher than those of the graphene based supercapacitors with aqueous or PC electrolytes reported previously. Furthermore, at a high discharge current density of 30 A g⁻¹, the energy and power densities of the supercapacitor were measured to be 15.4 Wh kg⁻¹ and 16 300 W kg⁻¹, respectively. These results indicate that the supercapacitor has a high specific capacitance and power density, and excellent rate capability.