Facile syntheses of Fe2O3-rGO and NiCo-LDH-rGO nanocomposites for high-performance electrochemical capacitors

Abstract

Faraday-type electrode materials and devices for electrochemical capacitors have been widely investigated. However, their applications are severely limited by the preparation method and cost of electrode materials. In this work, high-performance electrochemical capacitors were successfully assembled using Fe2O3-decorated reduced graphene oxide (rGO) nanocomposites and NiCo-Layered Double Hydroxides (LDH) as the anode and cathode, respectively. An easy and efficient approach (the modified precipitation method) for the large-scale fabrication was used to prepare Fe2O3 and NiCo-LDH, supported by rGO sheets, respectively. The anode material, Fe2O3-rGO, exhibited an excellent specific capacitance (Csp) of 1073 F g−1 at a current density of 1 A g−1 and a retention rate of 92 % at 10 A g−1, while the NiCo-LDH-rGO cathode material provided a Csp of 1850 F g−1 at 1 A g−1 and maintained 84 % at 10 A g−1. The effective combination of these electrodes for the NiCo-LDH-rGO//Fe2O3-rGO electrochemical capacitors resulted in an excellent energy density of 108 Wh/kg at a power density of 884 W/kg, with remarkable cycling stability (80 % after 1000 cycles at 10 A g−1). We believe that this work, including the proposed method and electrode materials, will advance the further development and commercialization of electrochemical capacitors.