Stabilizing Hybrid Electrochromic Devices through Pairing Electrochromic Polymers with Minimally Color-Changing Ion-Storage Materials Having Closely Matched Electroactive Voltage Windows

Conjugated electrochromic polymers hold great promises for next-generation color-changing windows and displays. One of the major roadblocks in their solid-state electrochromic devices is the relatively poor cycling stability. Finding ion-storage materials as a charge-balancing component is critical in improving their electrochemical cycling stability. A key criterion for the selection of ion-storage materials is to match their electroactive voltage windows with the paired electrochromic polymers. Thus, we developed a nanostructured, amorphous vanadium oxide (VOx) ion-storage material that exhibits high transmissivity, minimal color interference, and excellent charge-balancing capability in a closely matched electroactive window with the paired electrochromic polymers. High-performance magenta-to-transmissive hybrid electrochromic devices constructed from pairing the polymer with the VOx can be reversibly switched for 50 000 cycles with an optical loss less than 5%.