▎ 摘　　要

Tungsten oxide (WO3), which was originally poor in capacitive performance, is made into an excellent electrode material for supercapacitors by dispersing it on graphene (Gr). The obtained Gr-WO3 hybrids are characterized by X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy and scanning electron microscopy techniques, and evaluated as electrode materials for high-performance supercapacitors by cyclic voltammetry, galvanostatic charge-discharge curves and electrochemical impedance spectroscopy. A great improvement in specific capacitance is achieved with the present hybrids, from 255 F g(-1) for WO3 nanoparticles to 580 F g(-1) for Gr-WO3 hybrids (scanned at 1 A g(-1) in 2 M KOH over a potential window of 0 to 0.45 V). The Gr-WO3 hybrid exhibits an excellent high rate capability and good cycling stability with more than 92% capacitance retention over 1000 cycles at a current density of 5 A g(-1). The enhancement in supercapacitor performance of Gr-WO3 is not only attributed to its unique nanostructure with large specific surface area, but also its excellent electro-conductivity, which facilitates efficient charge transport and promotes electrolyte diffusion. As a whole, this work indicates that Gr-WO3 hybrids are a promising electrode material for high-performance supercapacitors.