Electrochromic device based on tungsten oxide and on Nnfion-H as polymeric electrolyte

We describe the preparation, electrical and optical characterization of a prototype of a nearly solid-state electrochromic device. It is fabricated with Nafion-H, a polymeric electrolyte, and involves cathodically coloring tungsten trioxide doped with molybdenum. The device switches rapidly with the applied potential ranging from –2.4 up to 0.8V, between blue and transparent state. The corresponding integrated photopic (T_p) and solar (T_s transmittance is T_p (bleached) = 70.7%, T_s (bleached) = 59.6%, T_p (colored) = 15.5%, and T_s (colored) = 12.2%.