(Invited) Solution-Processed Nanostructured Electrochromic Materials: Preparation and Application

Abstract

Electrochromic materials and devices can change color under applied potentials, which are widely studied for applications in energy-saving smart windows, rearview mirrors, displays, and so forth. The operation of electrochromic materials and devices involves the gain or loss of electrons and simultaneous insertion/extraction of ions with opposite charges to balance the internal electric fields. The performance is therefore limited by kinetics of charge transport in electrochromic materials as well as ion migration in electrolytes, materials and at their interfaces. Nanostructured electrochromic materials have an extremely short charge transport distance facilitating charge transport in electrochromic devices and large specific surface area improving the contact with electrolytes, which may result in enhanced electrochromic properties. By using solution-processed technology, we prepared nanostructured electrochromic materials, including hydrothermally synthesized WO3 nanorods, NiO nanosheets, flower-like NiO micro-nanostructures, well-adhesive WO3 and Prussian blue films directly grown on transparent conductive glass, electrodeposited Prussian blue film. Electrochromic devices based on these materials show their potential applications in smart windows, displays and self-rechargeable batteries.