Optical and electrochemical properties of vanadium pentoxide gel thin films

Abstract

Optical and electrochemical properties of vanadium pentoxide (V2O5) films prepared by sol-gel method from organic and inorganic precursors were studied. The organic gel was obtained by hydrolysis and polycondensation of vanadium isopropoxide dissolved in isopropanol. The inorganic gel was prepared from aqueous solution of sodium vanadate. Lithium insertion in LiyV2O5 films (0<y≤2.0) was investigated by cyclic voltammetry and electrochemical potential spectroscopy, showing good reversibility up to y∼2.0 and structure transitions from α phase to ε phase and δ phase in the range 0<y≤1.0. Highest values for chemical diffusion coefficient were about 3×10−10 cm2/s at y∼0.8, as determined from complex impedance measurements.