Electrochromic and Ex Situ IR and Raman Spectroelectrochemical Studies of LixInVO4 Films Charged/Discharged in the 0 < x < 1 Domain

Abstract

films were prepared using the sol-gel route from V-oxoisopropoxide and In-nitrate precursors. Films were made by dip coating deposition technique which allows the preparation of films with a thickness up to 230 nm by a single dipping cycle. The structure of crystalline films obtained at 500°C was investigated using Raman and IR spectroscopies, which were combined with X-ray diffraction. The crystalline films consist of a monoclinic phase with an admixed orthorhombic phase. Electrochemical investigations revealed that the charge capacity of the crystalline films (500°C) is about −40 mC significantly exceeding the ion storage capacity of amorphous films prepared at 300°C (−20 mC In situ UV-visible spectrolectrochemical studies of amorphous and crystalline films showed that the coloration of the films is cathodic with a change in a photopic transmittance from 0.034 to 0.149, respectively. Crystalline films exhibit higher coloring than amorphous films; this is related to their higher coloration efficiency The main focus is given to IR and Raman spectroelectrochemical studies of crystalline films (500°C) galvanostatically charged in the domain Vibrational spectra revealed that the monoclinic phase remains unchanged in the domain and transforms to the amorphous phase when charged in the domain. Vibrational band changes observed in Raman and IR spectra of charged and discharged films are assessed and correlated with the spectral features of and films studied previously. © 2001 The Electrochemical Society. All rights reserved.