Preparation of layered graphene and tungsten oxide hybrids for enhanced performance supercapacitors

• Published in: Dalton transactions : an international journal of inorganic chemistry 2016-11, Vol.45 (43), p.17439-17446
• Main Authors: Xing, Ling-Li, Huang, Ke-Jing, Fang, Lin-Xia
• Format: Article
• Language: English
• Subjects: Capacitance; Current density; Electrode materials; Graphene; Performance enhancement; Specific surface; Supercapacitors; Tungsten oxides
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c6dt03719d

Tungsten oxide (WO 3 ), 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-WO 3 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 WO 3 nanoparticles to 580 F g −1 for Gr-WO 3 hybrids (scanned at 1 A g −1 in 2 M KOH over a potential window of 0 to 0.45 V). The Gr-WO 3 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-WO 3 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-WO 3 hybrids are a promising electrode material for high-performance supercapacitors. Graphene-tungsten oxide hybrids are prepared and used for enhanced performance supercapacitor electrode materials.