Pt-induced reversible Zn electrodeposition for flexible, heatable smart windows with ultrafast response and low-driving-voltage

Flexible and heatable electrochromic smart windows. • Dense and dendrite-suppressed Zn electrodeposition during repeated plating/stripping cycles. • Ultrafast optical switching behavior driven by low operating voltage. • Long-term cycling stability exceeding 1000 coloration/bleaching cycles. Reversible Zn electrodeposition-based electrochromic smart windows are attractive owing to their simple configuration, fast optical response, and low energy consumption. However, uncontrolled dendritic growth of Zn during repeated electrodeposition severely limits the achievable coloring efficiency and long-term stability of such devices, hindering their commercial adoption. In this work, a Pt interfacial layer is introduced onto a flexible ZnO/Ag/ZnO/PET working electrode, effectively suppressing Zn dendritic growth and enabling the development of a flexible electrochromic device with enhanced performance and stability. Pt-induced abundant and uniform Zn nucleation leads to denser and less dendritic Zn electrodeposition, allowing a wide and reversible visible-light transmittance modulation from 6.2% to 60.5%, along with rapid coloring and bleaching response times of less than 6 s under ultra-low operating voltages. The device further exhibits stable electrochromic performance over 1000 cycles, excellent mechanical flexibility, and effective Joule heating capability for defrosting/defogging. This work provides an effective interfacial strategy for regulating repeated Zn electrodeposition and advances the development of flexible electrochromic smart windows for energy-efficient buildings and vehicles. A Pt interfacial layer is designed to suppress the dendritic growth of Zn on the working electrode of reversible metal electrodeposition devices through the enhancement of Zn nucleation density, enabling the regulation of repeated Zn plating/stripping and the development of flexible, heatable electrochromic smart window with remarkable and ultrafast optical modulation. Download: Download high-res image (44KB) Download: Download full-size image