A High‐Performance Asymmetric Supercapacitor Based on Tungsten Oxide Nanoplates and Highly Reduced Graphene Oxide Electrodes
Muhammad Ashraf, Syed Shaheen Shah, Ibrahim Khan, Md. Abdul Aziz, Nisar Ullah, Mujeeb Khan, Syed Farooq Adil, Zainab Liaqat, Muhammad Usman, Wolfgang Tremel, Muhammad Nawaz Tahir
Abstract
Abstract Tungsten oxide/graphene hybrid materials are attractive semiconductors for energy‐related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG//m‐WO 3 ASC), fabricated from monoclinic tungsten oxide (m‐WO 3 ) 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 H 2 SO 4 ) using three‐ and two‐electrode systems. The HRG//m‐WO 3 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‐WO 3 ASC displays long‐term cycling stability, maintaining 92 % of the original specific capacitance after 5000 galvanostatic charge–discharge cycles. The m‐WO 3 nanoplates were prepared hydrothermally while HRG was synthesized by a modified Hummers method.