Rapid, external acid-free synthesis of Bi2WO6 nanocomposite for efficient supercapacitor application

Background: It is crucial to create improved energy storage technologies, such as supercapacitors to reduce the erratic nature of natural energy sources, which heavily rely on the production of electroactive materials with optimal electrochemical properties. A symmetric supercapacitor may achieve a wide voltage window and prevent electrolyte breakdown by taking advantage of both battery-type and capacitor-type materials. This overcomes the energy limits of conventional supercapacitors. Recently, tungsten oxide-based materials have attracted attention as a family of attractive electrode materials for pseudocapacitors due to their greater electronic conductivity, eco-friendliness, strong electrochemical durability, variable oxidation state, and affordability. Methods: In this work, we have synthesized Bi2WO6 nanocomposite by a single-step redox reaction under hydrothermal conditions without using of any external acidic medium. Significant findings: The synthesized Bi2WO6 nanocomposite exhibits the highest specific capacitance of 363 F/g in neutral electrolyte. Moreover, the fabricated symmetric supercapacitor device of synthesized Bi2WO6 nanocomposite shows a maximum energy density of 26.18 Wh/kg and a power density of 5.4 kW/kg. The fabricated symmetric supercapacitor device exhibits excellent durability. The device demonstrates 89% specific capacitance retention after 5000 continuous charge-discharge cycles.