Synergistic Interaction of Dual‐Polymer Networks Containing Viologens‐Anchored Poly(ionic liquid)s Enabling Long‐Life and Large‐Area Electrochromic Organogels

Abstract

AbstractViologens‐based electrochromic (EC) devices with multiple color changes, rapid response time, and simple all‐in‐one architecture have aroused much attention, yet suffer from poor redox stability caused by the irreversible aggregation of free radical viologens. Herein, the semi‐interpenetrating dual‐polymer network (DPN) organogels are introduced to improve the cycling stability of viologens‐based EC devices. The primary cross‐linked poly(ionic liquid)s (PILs) covalently anchored with viologens can suppress irreversible face‐to‐face contact between radical viologens. The secondary poly(vinylidenefluoride‐co‐hexafluoropropylene) (PVDF‐HFP) chains with strong polar groups of ‐F can not only synergistically confine the viologens by the strong electrostatic effect, but also improve the mechanical performance of the organogels. Consequently, the DPN organogels show excellent cycling stability (87.5% retention after 10 000 cycles) and mechanical flexibility (strength of 3.67 MPa and elongation of 280%). Three types of alkenyl viologens are designed to obtain blue, green, and magenta colors, demonstrating the universality of the DPN strategy. Large‐area EC devices (20 × 30 cm) and EC fibers based on organogels are assembled to demonstrate promising applications in green and energy‐saving buildings and wearable electronics.