Facile preparation of WO3 nano-fibers with super large aspect ratio for high performance supercapacitor

WO3 nano-fibers with super large aspect ratio are synthesized on a Cu conductive current collector by using a simple hydrothermal method. The as-prepared WO3 nano-fibers can accommodate a large number of electrolyte ions and provide a rapid route for the migration of electrons and electrolyte ions due to its direct growth, high specific surface area, and one dimensional (1D) pipeline structure. The WO3 nano-fibers exhibit excellent cyclic reversibility (98% at 1.0 A g(-1)), good cycling stability (93% after 5000 cycles), high specific capacitance (436 F g(-1) at 1.0 A g(-1)) and low charge transfer resistance (29 Omega). After the WO3 nano-fibers are assembled into a symmetric supercapacitor, the symmetric supercapacitor device has a wide effective operating range of 0-1.8 V and high energy density of 99.0 Wh kg(-1) at the power density of 450 W kg(-1). The good electrochemical performances of as-prepared WO3 nano-fibers make it an attractive candidate for high energy storage systems and promising supercapacitor electrode material. (C) 2018 Elsevier B.V. All rights reserved.