Dynamic metal-ligand interaction of synergistic polymers for bistable see-through electrochromic devices.

Bistable electrochromic materials are a promising alternative solution to reduce the energy consumption in display. Limited by the mechanism and lack of design strategy, only a few electrochromic materials could truly achieve bistability. Herein, we proposed a novel strategy to design bistable electrochromic materials based on the polymer-assisted dynamic metal-ligand coordination. The mechanism and materials of such unconventional electrochromic systems were proved by sufficient characterization. Synergistic stabilization of polymerized switchable dyes and the ionic ligand polymer are attracted to each other by supramolecular forces. In this work, the color states of dye molecules were controlled and stabilized by the valence changes of metal ions. At the same time, through the polymerization of the EC material and the nearby metal ligand material, the metal ions of the electro-induced valence change were tightly fixed, and the related diffusion problem of the active EC component was also almost completely suppressed. This strategy successfully enabled us to prepare the corresponding low open voltage (0.7V), high transmittance (74%) transparent electrochromic display. It can keep the display information clearly visible for more than 1.5 h without consuming energy (transmittance attenuation rate <8%). More importantly, the new way of dynamic coordination or dissociation bistable display could likely prosper the development of the electrochromic area and inspire other fields with more pleasant surprise. This article is protected by copyright. All rights reserved.