Tungsten oxide-based nanomaterials for supercapacitors: Mechanism, fabrication, characterization, multifunctionality, and electrochemical performance

As a class of promising anode materials, tungsten oxide (WO3-x) based materials have been increasingly investigated for pseudocapacitors application, owing to their superior electronic conductivity, environmental friendliness, good electrochemical stability, and low cost. In this review, the development history and the charge storage mechanisms of WO3-x-based electrode materials are first presented. Then the various synthesis strategies of WO3-x based electrode materials and the relationship between microstructure and electrochemical performance are highlighted and summarized. This review also introduces the device performance and the multifunctional applications for WO3-x-based supercapacitors. Finally, the challenges and future directions for the further development of WO3-x-based high-performance supercapacitors are discussed.