Synthesis of vanadium oxide, V6O13 hollow-flowers materials and their application in electrochemical supercapacitors

Hollow flowers-like V6O13 with an average size of 3 mu m was successfully synthesized via a facile sol-hydrothermal approach in a short time. The surface composition, crystalline components and morphology of V6O13 were characterized by X-ray photoelectron spectra (XPS), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements, respectively. An intercalating-exfoliatingself- assembly model was proposed to explain the formation process of hollow-flower structure based on experimental results. The obtained hollow flowers-like V6O13 exhibits high specific capacitance, good cyclability and low resistance as revealed by analysis of cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS). Experimental results also indicate that hollow flowers-like V6O13 can deliver a capacitance of 417 F g(-1) at a scan rate of 5 mV s(-1). This value would decrease to 400 F g(-1) after 1000 cycles in potential range from 0 to 0.8 V versus saturated calomel electrode (SCE) in 1 mol L-1 NaNO3 aqueous electrolyte at pH of 2. (C) 2011 Elsevier B.V. All rights reserved.