Sustainable Rejuvenation of Scalable Large‐Area WO₃‐PB Electrochromic Devices

Abstract Electrochromic devices (ECD) have become a hot research topic in the field of green buildings due to their excellent energy efficiency and thermal management capabilities. Currently, challenges such as difficulties in large‐area preparation, high costs, and degradation of electrochromic performance over time have hindered their widespread application. A strategy incorporating a dual‐phase nanocrystalline structure of WO 3 and TiO 2 ·H 2 O is proposed, in which specific synthesis parameters are precisely controlled to tailor the microstructure and composition of the films, enabling the fabrication of large‐area WO 3 ‐PB ECD with UV‐rejuvenation electrochromic performance. As a result, the as‐prepared WO 3 ‐PB ECD exhibits an optical modulation of 75.6% and a remarkable cycle life exceeding 13,000 cycles. The electrochromic performance degradation caused by long cycles can be restored via UV irradiation. Utilizing UV light to restore the performance of these WO 3 ‐PB ECDs promotes sustainable and environmentally friendly development, highlighting their important practical value.