Unlocking Scalable Manufacturing of Electrochromic Windows: Wadsley-Roth TiNb2O7 Films with Open Shear Channels for Intelligent Photo-Thermal Management

Electrochromic smart windows represent a promising technology for reducing building energy consumption through dynamic photo-thermal regulation. However, scalable fabrication of high-performance electrochromic films remains challenging. Herein, we pioneer slot-die coating technique and aqueous inks for the high-speed production (600 cm 2 /min) of Wadsley-Roth structure TiNb 2 O 7 films. Experimental and theoretical analyses reveal that the open crystallographic shear channels in TiNb 2 O 7 enable efficient ion transport with a low diffusion barrier of 0.22 eV, allowing it to achieve a high diffusion coefficient (6.34 × 10 −10 cm 2 /s), good uniformity, and 82.8% large optical modulation at 600 nm. We constructed a series of large-scale electrochromic devices with a size up to 200 cm 2 that demonstrate significant optical modulation (64.6%), rapid switching (23.4/12.4 s), and uniform coloration. We evaluated the photo-thermal management performance of the device using a xenon lamp as a simulated solar source, achieving a notable temperature regulation of 18.8°C. To further validate its practical applicability, we conducted an outdoor test, demonstrating a temperature modulation of ∼5.0°C. Additionally, energy simulation analyses reveal that the device enables an energy saving of 155 MJ·m −2 . This work provides a scalable manufacturing strategy for high-performance electrochromic devices, advancing the development of intelligent energy-saving window technology.