UV-Activated Large-Area Switchable Electro-Reflective Window for Energy-Efficient Electric Vehicles

Abstract

The development of electrically driven smart glass with controlled modulation of solar radiation provides a reliable solution to seasonal fluctuations in cabin temperature, privacy leakage, and range anxiety in electric vehicles. However, the preparation of large-area electrochromic glass for cooling in summer and heating in winter remains a challenging task. Here, an electro-reflective device (ERD) with solar reflectance of 0.808 in the mirror state and solar transmittance of 0.637 in the transparent state is obtained by simple UV-activated operation of the device with a three-layer structure (ITO glass/electrolyte/ITO glass). The UV activation promotes the electrodeposition of finer, denser metal particles, reduces the electrodeposition voltage of Ag⁺ by 29.2% and improves the light transmittance in the transparent state, which provides conditions for the expansion of the working area (up to 1726 cm²) and the enhancement of the seasonal temperature control. Simulation results show that ERD has achieved energy savings in air conditioning systems globally, with annual energy savings of 47.2% in the tropical city of Mexico City, demonstrating the potential to extend the driving range through thermal management optimization. This work provides a new solution for all-season energy savings in electric vehicles, helping to promote the electric vehicle business.