Synthesis and electrochemical evaluation of WS2/WO3-x heterostructure for binder-free high-performance supercapacitors

Abstract

Transition metal-based electrodes are the forefront of advanced supercapacitor research due to their tunable redox activity and structural versatility. In this work, a binary composite tungsten disulfide/tungsten oxide (WS₂/WO_3-x) material was synthesized via an atmospheric pressure chemical vapor deposition (APCVD) technique and its application as a binder-free electrode for high-performance supercapacitors is studied. The as-synthesized WS₂/WO_3-x binary composite possesses a hierarchical flower-rod like morphology, resulting in combined electric double-layer and pseudocapacitive capacitance. A symmetric supercapacitor is assembled by coating WS₂/WO_3-x on a carbon cloth. The symmetric supercapacitor delivers an excellent specific capacitance of 380.8 F/g at 0.083 A/g with an energy density of 33.8 Wh/kg and power density of 133.3 W/kg. The electrode retains 84% of its initial capacitance after 2100 cycles at a current density of 2.6 A/g, underscoring its excellent cycling stability. Thus, these observed excellent electrochemical performances establish the WS₂/WO_3-x binary composite based electrodes, suggesting their tremendous potential as supercapacitor electrodes for energy storage systems.