Fast Photothermal Regulation of All‐in‐One Electrochromic Dynamic Windows Based on Synergetic Electrodeposition of CuBi and MnO ₂

ABSTRACT Electrochromic dynamic windows represent an attractive avenue for enhancing the energy‐saving efficiency of buildings. However, the practical application of dynamic windows remains in its infancy due to challenges related to efficient optical modulation and cost‐effective manufacturing. Herein, we report an all‐in‐one electrochromic dynamic window through synergetic electrodeposition of CuBi and MnO 2 , featuring a simplified three‐layer configuration. The synergy of dual electrodeposition, coupled with Br − /Br 3 − redox pair, endows the CuBi//MnO 2 system with reversible color transitions between transparent and brown‐black states. Benefiting from a well‐balanced charge distribution, the CuBi//MnO 2 system demonstrates superior photothermal regulation in the visible‐near‐infrared region, including large optical modulation of 90.6% at 500 nm and 58% at 1100 nm, short response time of 16.1/12.9 s at 500 nm and 21.4/8.1 s at 1100 nm in coloration/bleaching processes. Outdoor test indicates that the assembled large‐size dynamic window can lower the temperature by 5 to 10°C within a homemade house. Further simulation suggests that implementing the dynamic window can reduce annual energy consumption in buildings by up to 95.7 MJ/m 2 and decrease average CO 2 emissions by 18.8 kg/m 2 in subtropical regions of China. Our work offers a straightforward and effective strategy for developing low‐cost energy‐saving dynamic window technologies.