Long-life Inorganic Electrochromic Device Based on WO3 and PB Films with Fast Switching Respond

Abstract Complementary electrochromic devices were fabricated by using tungsten trioxide (WO 3 ) film as working electrode, Prussian blue (PB) film as counter electrode and 0.1 M lithium perchlorate in propylene carbonate as electrolyte. The XRD result presents that WO 3 and PB films are amorphous, which is favourable for a fast ion intercalation-deintercalation process. The device was tested under potentiostatic control using ±1.3 V steps, and changed its color between blue and colorless. It has a fast-switching respond (about 1.5 s for colouring and 2 s for bleaching) and could withstand 100,000 cycles with little change in its optical contrast.