Enhanced Fast Switching of Viologen‐Based Electrochromics Using Hybrid Electrolytes

Among various electrochromic materials for electrochromic devices (ECDs), viologens are particularly attractive owing to their intense optical contrast, stable redox behavior, and low operating voltages. Recent progress in this field has primarily centered on modifying molecular structures and designing confinement architectures to enhance performance, yet it remains comparatively underexplored in viologen ECDs. Herein, we demonstrate viologen‐based electrochromic devices incorporating a 1,2‐dimethoxyethane/dioxolane (DME/DOL) mixed solvent, which exhibit improved optical contrast and faster coloration/bleaching kinetics compared with devices using conventional electrolytes. The DME/DOL hybrid electrolyte system enables faster ion diffusion and reduced charge transfer resistance, confirmed through chronoamperometry analysis and electrochemical impedance spectroscopy. 7 Li NMR spectrum and electrostatic potential (ESP) analysis reveal stronger lithium ion shielding and more extensive negative electrostatic potential distribution around viologen species in DME/DOL, facilitating lithium ions diffusion for efficient charge compensation during redox switching. This work highlights hybrid electrolyte engineering as a powerful strategy to optimize viologen electrochromic devices for fast switching and explained mechanism based on experimental results combined with computational analysis, which can inform the development of next‐generation solution‐processed optical functional materials and devices.