Cycling Stability of an Electrochromic System at Room Temperature

A solid-state electrochromic transparency, of electrically conductive glass/WO 3-y .mH 2 O/solid polymer electrolyte/Cu grid/clear glass, has been shown elsewhere to carry current efficiently over a large area. It provides electrochromic reactions without significant optical transparency loss for more than 10,000 repeated cycles at room temperature. An equivalent-circuit analysis has been applied to this electrochromic system to gain insight into the physical nature of electrochromic switching. Darkening and bleaching are treated separately due to the unsymmetrical nature of the processes