Nano tungsten oxide may be applied in the field of thermal insulating glass with excellent thermal insulation properties and high visible light transmittance. Tungsten oxide also has electrochromic properties and therefore can be used on electrochromic devices.
The electrochromic device is generally composed of five-layer structure, which can be divided into two transparent conductor layers (TC), a counter electrode layer (CE), an ion conductor layer (IC), and an electrochromic layer (EC) sandwiched therebetween. If tungsten oxide is used as an electrochromic layer, under the action of an external electric field, the counter electrode layer transmits ions to the electrochromic layer through the ion conductor layer. And the corresponding equivalent amount of electrons is introduced into the electrochromic layer through the transparent conductor layer through an external circuit. The tungsten oxide in the electrochromic layer undergoes electrochromic reaction as shown below by means of electron and ion double injection:
WO3(bleached state) + xM+ + xe−⇔MxWO3(colored state)
Among them, M+ is usually cations with small radius. These cations have good mobility, among which hydrogen ions and lithium ions are common.
More details, please visit:
http://www.tungsten-powder.com/tungsten-oxide.html
