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

Abstract

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.

Tuning Electron Transfer in Pyrene-Based Two Dimensional Covalent Organic Frameworks: Unveiling the Impact of Semi-isomerism on Physicochemical Properties

“…The response time was determined from measurements of ΔT%, i.e., the time required for the optical modulation ratio to reach 95% of their maximum. , The coloration time (t c ) and bleaching time (t b ) of the COFs film electrodes were calculated to be 0.29 s/2.1 and 0.72 s/3.8 s, respectively (Figure e). The SI-Py COFs exhibited a more pronounced response in both the colored and bleached states, which might be attributed to the shorter electron transfer path present in SI-Py COFs.…”

Advanced inorganic nanomaterials for high-performance electrochromic applications

“…Generally, EC materials can be divided into organic materials and inorganic materials. 20–22 Organic EC materials mainly include organic small molecules (viologen and its derivatives) 25 and conducting polymers ( e.g. , polyaniline, polythiophene, polypyrrole, and their derivatives).…”

Conductivity and Transference Numbers in Lithium Salt-Doped Block Copolymeric Ionic Liquid Electrolytes

“…Polymeric ionic liquids (PolyILs), which consist of monomeric ionic liquids (ILs) as the building block of macromolecules, are a novel class of solid polymer electrolytes (SPEs) that have shown promise in electrochemical energy applications. − By inheriting the unique physicochemical properties of ILs, , PolyILs exhibit several advantages in comparison with conventional electrolyte materials, such as enhanced chemical stability, nonflammability, and nontoxicity . Hence, significant interest has arisen in the properties of both pure PolyILs and salt-doped PolyILs. − …”