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–RuO₂) 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–RuO₂ 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–RuO₂ (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.