Tungsten oxide powder for producing liquid electrochromic device is an electrochromic material, more specifically, an inorganic electrochromic material. And usually tungsten trioxide film rather than tungsten trioxide powder is used to assemble an electrochromic device. In fact, the electrochromic material can be further divided into a cathode electrochromic material and an anode electrochromic material in accordance with the coloring method. And tungsten oxide belongs to the cathode electrochromic material.
More details, please visit:
http://www.tungsten-powder.com/tungsten-oxide.html
As you may have known, inorganic electrochromic materials generally consist of transition metal oxides or their derivatives. But do you know why inorganic electrochromic materials are transition metal oxides or their derivatives? This is because in the transition metal oxide, there are unpaired single electrons on the d orbital of the metal element, which makes the structure of the electron layer unstable. Therefore, under certain conditions, the valence state is reversibly transformed to form a mixed valence state. And as the ion concentration and valence change, the color also changes. In other words, the color of tungsten oxide film changes with the change of ion concentration and valence.
