Bidirectional Color Switching and Multimodal Energy Outputs Enabled by Synergistic Complementary Color Fusion and Inherent Potential Gradient in a Fully-Printed Tri-Electrode Electrochromic System

Self-powered electrochromic devices, which integrate optical modulation with energy storage, represent a significant direction in adaptive optics and smart electronics. However, they still face limitations such as monotonous operation modes, slow self-charging, and complex fabrication processes. To address these challenges, we present a novel self-powered electrochromic system (MnO 2 ||PEDOT:PSS/PANI:PSS||Zn) based on a synergistic strategy of complementary color fusion and potential gradient utilization. The electrochromic electrode exploits the complementary color fusion effect between the cathodic electrochromic material PEDOT:PSS and the anodic electrochromic material PANI:PSS, enabling distinct color manifestations (green, purple, and blue) at different redox states. The inherent potential gradient among MnO 2 , PEDOT:PSS/PANI:PSS, and Zn provides a robust driving force for the redox reactions in the electrochromic electrode, allowing the system to achieve rapid and reversible bidirectional color switching along with multiple output modes. Via a fully-printed fabrication process, we integrated the three electrodes onto a single paper substrate, constructing a compact, mechanically flexible, multi-mode self-powered electrochromic system. This system has been successfully applied in reconfigurable multicolor display arrays and pressure-activated connected smart display labels. We envision that this work provides new insights into the development of flexible, multifunctional energy-optical systems.