Multi‐Color Flexible Electrochromic Device for Smart Anti‐Counterfeiting

Information security is critically important. We propose a multilevel electrochromic display design for dynamic information encryption, enabled by Prussian blue, zinc, and potassium nickel hexacyanoferrate. The as-fabricated electrochromic devices offer a two-dimensional CIE color space modulation with four distinct states from transparent to blue, green, and yellow. The devices facilitate precise, localized, and dynamic modulation of electrochromism via an elaborately designed and independently addressable pattern configuration, enabling advanced encryption and identity authentication with enhanced adaptability. This approach achieves superior security through multi-stage authentication, real-time color modulation, and adjustable smart encryption levels tailored to different specific requirements. Our work envisions a new generation of flexible electrochromic devices that elevate both display performance and information security.