All-solid-state electrochromic device composed of WO3 and Ni(OH)2 with a Ta2O5 protective layer

An all-solid-state electrochromic device composed of WO3 and Ni(OH)2 with a Ta2O5 protective layer was prepared by rf magnetron sputtering and lamination with a proton-conducting solid polymer electrolyte. This device had good durability, high transmittance modulation (18%–74%) and coloration efficiency (about 84 cm2 C−1), and good response times (8.5 and 18 s, respectively, during the bleaching and coloring processes). This indicates that Ta2O5 layers are electrochemically stable and can be used as protective layer for Ni(OH)2 as well as WO3.