A High-Performance Asymmetric Supercapacitor Based on Tungsten Oxide Nanoplates and Highly Reduced Graphene Oxide Electrodes

Abstract

Tungsten oxide/graphene hybrid materials are attractive semiconductors for energy-related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG//m-WO3 ASC), fabricated from monoclinic tungsten oxide (m-WO3) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material. The supercapacitor performance of the prepared electrodes was evaluated in an aqueous electrolyte (1 m H2SO4) using three- and two-electrode systems. The HRG//m-WO3 ASC exhibits a maximum specific capacitance of 389 F g−1 at a current density of 0.5 A g−1, with an associated high energy density of 93 Wh kg−1 at a power density of 500 W kg−1 in a wide 1.6 V operating potential window. In addition, the HRG//m-WO3 ASC displays long-term cycling stability, maintaining 92 % of the original specific capacitance after 5000 galvanostatic charge–discharge cycles. The m-WO3 nanoplates were prepared hydrothermally while HRG was synthesized by a modified Hummers method.