Electrochromism refers to the phenomenon that the optical properties (reflectivity, transmittance, absorptivity, etc.) of materials change stably and reversibly under the action of external electric field, which is manifested in the reversible change of color and transparency in appearance. Materials with electrochromic properties are called electrochromic materials, and devices made of electrochromic materials are called electrochromic devices.

APG in Electrochromism indusrty to provide target material basically has：