Investigation of lithium transport through an electrodeposited vanadium pentoxide film electrode

Abstract

Lithium intercalation into vanadium pentoxide film electrodes prepared by electrodeposition methods has been investigated in a I M solution of LiClO4 in propylene carbonate (PC) by employing potentiostatic current transient technique. From the analysis of the current transient experimentally measured, it is proposed that lithium transport through the electrodeposited vanadium pentoxide film electrode is exclusively controlled by the cell impedance. The theoretical current-time relation has been analytically obtained from the solution to the diffusion equation under the assumption of the cell impedance-controlled constraint at the electrolyte/electrode interface. On the basis of the theoretical current transient, the current transient experimentally measured has been analysed to estimate the kinetic parameters governing lithium intercalation such as the cell impedance and the chemical diffusivity of lithium. In particular, the chemical diffusivity of lithium was determined to be 2.1 X 10(-13) to 2.1 X 10(-10) cm(2) s(-1), and was found to be in good accordance with that obtained from electrochemical impedance spectroscopy. (C) 2003 Elsevier Science B.V. All rights reserved.