A high-performance asymmetric supercapacitor fabricated with graphene-based electrodes

Abstract

An asymmetric supercapacitor (ASC) was fabricated using reduced graphene oxide (RGO) sheets modified with ruthenium oxide (RGO-RuO 2) or polyaniline (RGO-PANi) as the anode and cathode, respectively. The ASC exhibited a significantly improved capacitive performance in comparison with that of the symmetric supercapacitors fabricated with RGO-RuO 2 or RGO-PANi as the electrodes. The improvement was attributed to the broadened potential window in an aqueous electrolyte, leading to an energy density of 26.3 W h kg -1, about two-times higher than that of the symmetrical supercapacitors based on RGO-RuO 2 (12.4 W h kg -1) and RGO-PANi (13.9 W h kg -1) electrodes. In addition, a power density of 49.8 kW kg -1 was obtained at an energy density of 6.8 W h kg -1. © 2011 The Royal Society of Chemistry.