Viologens‐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.
Stretchable electrochromic (EC) devices that can adapt the irregular and dynamic human surfaces show promising applications in wearable display, adaptive camouflage, and visual sensation. However, challenges exist in lacking transparent conductive electrodes with both tensile and electrochemical stability to assemble the complex device structure and endure harsh electrochemical redox reactions. Herein, a wrinkled, semi‐embedded Ag@Au nanowire (NW) networks are constructed on elastomer substrates to fabricate stretchable, electrochemically‐stable conductive electrodes. The stretchable EC devices are then fabricated by sandwiching a viologen‐based gel electrolyte between two conductive electrodes with the semi‐embedded Ag@Au NW network. Because the inert Au layer inhibits the oxidation of Ag NWs, the EC device exhibits much more stable color changes between yellow and green than those with pure Ag NW networks. In addition, since the wrinkled semi‐embedded structure is deformable and reversibly stretched without serious fractures, the EC devices still maintain excellent color‐changing stability under 40% stretching/releasing cycles.
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