Electrochromism in Polymer‐Electrolyte‐Enabled Nanostructured WO3: Active Layer Thickness and Morphology on Device Performance

Herein, we showcase the ease and feasibility of integrating a quasi‐solid semi‐IPN electrolyte supporting Li+‐ion conduction with nanostructured WO3 to achieve a functional electrochromic device with impressive performance and stability. Co‐continuous WO3 electrodes, obtained layer‐by‐layer, reveal interesting changes in morphology from plate‐like structures to nanoparticles. The nanostructured electrodes offer a large surface area and a sufficiently open architecture for realizing effective permeation of the polymeric electrolyte. WO3 films (∼300 nm) achieved with five repetitive deposition‐spin cycles (5 L) provide best coverage, electrolyte wetting and device characteristics. Redox efficiency and reversibility >2000 cycles indicates a stable electrode‐electrolyte interface and device performance. A considerably high coloration efficiency of ∼134 cm2 C−1, an appreciably fast switching response (