Transparent Zinc‐Mesh Electrodes for Solar‐Charging Electrochromic Windows

Abstract Newly born zinc‐anode‐based electrochromic devices (ZECDs), incorporating electrochromic and energy storage functions in a single transparent platform, represent the most promising technology for next‐generation transparent electronics. As the existing ZECDs are limited by opaque zinc anodes, the key focus should be on the development of transparent zinc anodes. Here, the first demonstration of a flexible transparent zinc‐mesh electrode is reported for a ZECD window that yields a remarkable electrochromic performance in an 80 cm2 device, including rapid switching times (3.6 and 2.5 s for the coloration and bleaching processes, respectively), a high optical contrast (67.2%), and an excellent coloration efficiency (131.5 cm2 C−1). It is also demonstrated that such ZECDs are perfectly suited for solar‐charging smart windows as they inherently address the solar intermittency issue. These windows can be colored via solar charging during the day, and they can be bleached during the night by supplying electrical energy to electronic devices. The ZECD smart window platform can be scaled to a large area while retaining its excellent electrochromic characteristics. These findings represent a new technology for solar‐charging windows and open new opportunities for the development of next‐generation transparent batteries.