Flexible Solid‐State Symmetric Supercapacitors Using HxWO3@Reduced Graphene Oxide Composite with High Volumetric Energy and Power Densities

Abstract

AbstractWe have synthesized hydrogen tungsten oxide decorated reduced graphene oxide (HxWO3@rGO) composite with different precursor weight ratios of WS2 and GO, of which the WG1‐2 system, produced from WS2 and GO in the 1 : 2 weight ratio by treatment with hydrogen peroxide followed by hydrothermal treatment, shows high areal capacitance of 409 mF cm−2 at 1 mA cm−2 current density with retention of 61.4 % at 20 mA cm−2 current density. This HxWO3@rGO composite is drop‐cast onto graphite layer‐coated on scotch tape to design a flexible supercapacitor. The flexible solid‐state symmetric supercapacitor based on the WG1‐2 composite shows a high volumetric capacitance of 3.56 F cm−3 and ultrahigh energy density of 1.6 mW h cm−3 at 1469.43 mW cm−3 power density.