Anchoring carbon layers and oxygen vacancies endow WO(3−x)/C electrode with high specific capacity and rate performance for supercapacitors

Herein, novel hierarchical carbon layer-anchored WO(3−x)/C ultra-long nanowires were developed via a facile solvent-thermal treatment and a subsequent rapid carbonization process. The inner anchored carbon layers and abundant oxygen vacancies endowed the WO(3−x)/C nanowire electrode with high conductivity, as measured with a single nanowire, which greatly enhanced the redox reaction active sites and rate performance. Surprisingly, the WO(3−x)/C electrode exhibited outstanding specific capacitance of 1032.16 F g(−1) at the current density of 1 A g(−1) in a 2 M H(2)SO(4) electrolyte and maintained the specific capacitance of 660 F g(−1) when the current density increased to 50 A g(−1). Significantly, the constructed WO(3−x)/C//WO(3−x)/C symmetric supercapacitors achieved specific capacitance of 243.84 F g(−1) at the current density of 0.5 A g(−1) and maintained the capacitance retention of 94.29% after 5000 charging/discharging cycles at the current density of 4 A g(−1). These excellent electrochemical performances resulted from the fascinating structure of the WO(3−x)/C nanowires, showing a great potential for future energy storage applications.