Long-term-stable WO3-PB complementary electrochromic devices

Abstract The complementary electrochromic devices based on WO3 and Prussian blue electrodes (PB) have shown a limited chemical stability and durability because WO3 is degraded in electrochromic performance and PB is gradually dissolved in the Li+-based electrolyte under neutral pH conditions. Herein, the utilization of acetic acid as super-additive solution was proposed to improve WO3 cathodes and stabilize PB anodes, in which the highly nanoporous nanocrystal-in-glass WO3 and hierarchical PB was made by electron beam evaporation and electrochemical deposition method, respectively. Our findings suggest that synergistic effects of Li+ and H+ on WO3 and Prussian blue electrodes contribute to the improvement on electrochemical, electrochromic, and cycling stability performance of the whole device. Impressively, the WO3-PB complementary electrochromic device could experience a superior long-term cycling stability of over 10,000 cycles, with a high coloration efficiency of 137.80 cm2 C−1 and a maximum transmittance modulation of 66.22%@ 633 nm. All these results open a new way to the construction of high-performance electrochromic devices.