Synthesis of V2O5 center dot 1.6H(2)O/graphene composite and its application in supercapacitors

摘要

V2O5 center dot nH(2)O/graphene composite is synthesized by self-assembly of V2O5 center dot 1.6H(2)O nanobelts on the surface of graphene via a simple hydrothermal method. The structure and morphologies of the composites are characterized by thermogravimetry analyzer, x-ray diffraction, and scanning electron microscope, respectively. It's found that the V2O5 center dot 1.6H(2)O nanobelts are in width of 90 nm and length of 1.5 mu m. The electrochemical behaviors of the composites in supercapacitors are tested by cyclic voltammetry and galvanostatic charge/discharge in a three-electrode system in KCl aqueous solution. Three pairs of redox peaks and voltage plateaus are observed correspondingly in the cyclic voltammetry curves and galvanostatic charge/discharge curves. The hybrid capacitance of this composite reaches 579 F/g at current density of 1 A/g and decreases 21 % after 5000 cycles at 4 A/g.