3D mesoporous reduced graphene oxide with remarkable supercapacitive performance

Abstract

Chemical reduction of graphene oxide (GO) to reduced graphene oxide (rGO) is an important process in view of the development of graphene-based supercapacitors on industrial level. We report an in situ chemical reduction of GO by copper(I) salt (CuCl) and isolation of semiconducting rGO material with three-dimensional (3D) mesoporous structure. Fabricated all-solid-state supercapacitors of our rGO exhibited specific capacitance and energy density values as high as 310 F/g at a current density of 1 A/g and 10 Wh/kg, respectively in an eco-friendly aqueous gel polymer electrolyte (GPE) system. Furthermore, increasing the mass loading of rGO boosted the areal capacitance to a record value of about 580 mF/cm2 at 1 mA/cm2 current density. More than 80% capacitance was retained beyond 100,000 continued charge-discharge (CD) cycles. Also, sustainability of our rGO supercapacitor over switching current densities in the CD cycles was excellent resembling the rate performance in battery-like energy storing devices. The use of organic electrolyte boosted the energy density of rGO to very high level of ∼22 Wh/kg.