The electrolyte is a pure ion conductor and separates the two EC layers. In this structure there are three principally different kinds of layered materials in the ECD: The EC layer and ion-storage layer conduct ions and electrons and belong to the class of mixed conductors. The basic structure of electrochromic device embodies five superimposed layers on one substrate or positioned between two substrates in a laminated configuration. Laminated ECD are the one in which liquid gel is used while in solid electrolyte EC devices solid inorganic or organic material is used. Electrochromic devices can be categorized in two types depending upon the kind of electrolyte used viz. The ECD works on an external voltage, for which the conducting electrodes are used on the either side of both EC layers.
The basic structure of ECD consists of two EC layers separated by an electrolytic layer.
Various types of materials and structures can be used to construct electrochromic devices, depending on the specific applications.Ĭross-sectional diagram showing the layers of a typical laminated electrochromic deviceĮlectrochromic (sometimes called electrochromatic) devices are one kind of electrochromic cells. The electrochromism occurs due to the electrochemical redox reactions that take place in electrochromic materials. Deb’s seminal paper of 1973, wherein he described the coloration mechanism in WO 3. In fact, the real birth of the EC technology is usually attributed to S. Deb observed electrochromic color by applying electric field of the order of 10 4 Vcm −1 across WO 3 thin film. Deb demonstrated electrochromic coloration in WO 3 thin films. Kraus provided a detailed description of electrochemical coloration in thin film of tungsten trioxide (WO 3) on 30 July 1953. While working at Balzers in Lichtenstein, T. In the 1930s, Kobosew and Nekrassow first noted electrochemical coloration in bulk tungsten oxide. The history of coloration goes back to 1704 when Diesbach discovered Prussian blue (hexacyanoferrate), which changes the color from transparent to blue under oxidation of iron.