Porous structured vanadium oxide electrode material for electrochemical capacitors

摘要

A nano porous vanadium oxide (V_2O_5) was prepared by sol-gel method. The preparation involved elutriation of aqueous sodium meta vanadate over a cation exchange resin. The product was characterized using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, surface area analysis and thermogravimetric analysis. Electrochemical characterization was done using cyclic voltammetry in a three electrode system consisting of a saturated calomel electrode as reference electrode, platinum mesh as a counter electrode, and V_2O_5 mounted on Ti mesh as the working electrode. Two molars of aqueous KCl, NaCl and LiCl were used as electrolytes. A maximum capacitance of 214 F g~(-1) was obtained at a scan rate of 5 mV s~' in 2 M KCl. The effect of different electrolytes and the effect of concentration of KCl on the specific capacitance of V_2O_5 were studied. Specific capacitance faded rapidly over 100 cycles in 2 M KCl at a 5 mV s~(-1) scan rate.