Extraordinarily fast response all-solid-state electrochromic devices

Abstract

Gel polymer electrolytes have been acknowledged as a promising candidate within the realm of electrochromic devices (ECDs) for addressing the safety concerns of liquid electrolytes and overcoming the poor ionic conductivity inherent in solid electrolytes. Herein, a novel strategy for the simple fabrication of in-situ UV-curable gel polymer electrolytes has been proposed to enhance ionic conductivity and promote interface interactions, thereby facilitating remarkably fast response times. After rapid photopolymerization, the electrolyte containing 10 wt% trimethylolpropane ethoxylate triacrylate exhibits the highest ionic conductivity (1.42 mS cm⁻¹), which is raised to a value of 1.79 mS cm⁻¹ by the incorporation of alumina inorganic nanoparticles. Additionally, the polymer electrolyte demonstrates high optical transmittance, relatively notable interface adhesive strength (26 KPa), and outstanding thermal stability, with only a 5 % weight loss observed up to 126 °C. These distinctive characteristics enable the fabrication of all-solid-state WO₃-NiO ECDs characterized by large optical modulation (50.82 %), super-short switching times (0.8 s for bleaching and 4.0 s for coloration), and exceptional cycling stability (95.7 % after 10,000 cycles, and 77.4 % after 15,000 cycles). This article effectively explores a straightforward method for fabricating high-performance all-solid-state ECDs, simplifying the process flow and enhancing the application prospects for ECDs.