The Electrochemical Behavior of Anodically Electrodeposited Iridium Oxide Films and the Reliability of Transmittance Variable Cells

Abstract

The electrochemical properties of anodically electrodeposited iridium oxide films are investigated for application to transmittance variable cells. The reactivity of electrochromic reaction of the film increases with the increase in water content in LiClO4 propylene carbonate electrolyte, and decreases with increasing temperature of the heat treatment after electrodeposition. The coloration potential E of the film depends on the proton activity in the electrolyte, and increases linearly with the hydrogen electrode potential E' of the electrolyte at a slope of 1.0. This means that the coloration is caused by the release of H+ from the film or by the injection of OH- into the film. The reliability of transmittance variable cells made with the films is tested.