A Lithium‐Salt‐Free, Hydrophobic, Solid‐State Poly(Ionic Liquid) Electrolyte Enables Rapid Assembly of Unencapsulated, Removable Electrochromic “Window Tint Film”

Abstract

Electrochromic technology that enables modulation of a material's optical properties by application of an applied voltage is utilized in smart windows. However, avoiding water absorption by lithium salt in the electrolyte necessitates complex encapsulated device assemblies that must be constructed under strict atmosphere conditions and are largely unrepairable. Herein, a lithium‐salt‐free, hydrophobic, solid‐state poly(ionic liquid) electrolyte based on strong C─F bonds that exhibits low polarizability, low moisture absorption, and a wide electrochemical window, allowing the fabrication of unencapsulated electrochromic devices with outstanding long‐term cycling and environmental stability are presented. Intimate contact between the electrolyte and the electrode is achieved through integrated in situ polymerization, providing an interface with multiple molecular interactions that impart robust adhesion, efficient ion transport, and excellent stability. To demonstrate the potential of this electrolyte for cost‐effective electrochromic smart windows, low‐cost (≈110 USD m−2), unencapsulated, removable, electrochromic “window tint film” with customizable dimensions and shapes are fabricated.

Efficient Bifunctional NiFe-LDH@Co9S8 Nanoflower Electrocatalysts Anchored with Pt Nanocrystal for Flexible Quasi-solid Rechargeable Zinc Air Battery

“…The most remarkable thing was that the hydrogel could maintain the electrolytes when FZABs were folded. In general, the optimized hydrogel electrolytes for hydrogels should meet the following three conditions: (1) high ionic conductivity; (2) high water uptake and strong water retention; and (3) stability with alkane. , Organic ionic liquid (IL), as additive, was widely used in the hydrogel to form an organohydrogel to prevent water evaporation. , Therefore, we designed a hydrogel composed of sodium polyacrylate (PANa), carboxymethyl cellulose (CMC) as polymer skeleton, and 1-ethyl-3-methylimidazolium chloride (EMImCl), acetamide as IL, which absorbed the water from air to alleviate water loss. The PANa-CMC-IL hydrogel exhibited a higher ionic conductivity (136.4 mS cm –1 ) than that of that of PANa (87.8 mS cm –1 ) and PANa-CMC hydrogel (94.4 mS cm –1 ) based on the Nyquist plot of the three types of hydrogel (Figure b).…”

Full color control and patterned display device from cyan/magenta/yellow water-dispersed electrochromic polymer nanoparticles systems

“…Electrochromism can be defined as a reversible change in the optical properties of a material under an applied voltage [1][2][3]. Electrochromic (EC) materials have potentially broad applications in smart windows, anti-glare mirrors, flexible displays, and military camouflage [4][5][6][7]. Compared with inorganic EC materials, conjugated polymers have been widely studied due to their rich colors, fast switching time, high optical contrast, and easy processing methods, which could be the promising EC materials to achieve the requirement of the multi-color or full-color for flexible display fields [8][9][10].…”

Complementary electrochromic device via a scalable solution process: a step towards affordable and energy-efficient smart windows

“…ECDs have garnered significant interest for their ability to offer user-controlled light transmission, presenting a viable solution to the challenge of balancing energy efficiency and user comfort. 3–8 A standard structure of ECD consists of four layers where an electrolyte is sandwiched between a bare transparent conducting electrode (TCE) and a TCE hosting an electrochromic (EC) film. A variant of this design, the complementary ECD (CECD) involves an extra EC layer on the bare TCE to enhance the optical contrast via a complementary coloration mechanism.…”