Fast Visible-to-Infrared Electrochromic Devices Based on Electrochemically Fabricated Polyaniline

Polyaniline-based electrochromic devices exhibit excellent adaptive camouflage potential in both visible and infrared spectral regions, but they currently still suffer from a slow response issue. Here, a fast visible-to-infrared electrochromic device based on electrochemically fabricated [BSO₃]Py·HSO₄-doped polyaniline is demonstrated. The electrochromic device achieves an ultrafast electrical response time of 0.5 s for coloration and 0.9 s for bleaching as well as maximum emissivity modulation of 0.35 in 3-5 μm and 0.51 in 8-14 μm bands. The device is fabricated by direct electrochemical polymerization of aniline monomers on Au-plated nylon porous electrodes with mixed ionic liquids of [BSO₃]Py·HSO₄/[BMIM]BF₄ simultaneously as acidic precursor solution and gel electrolyte, termed as a one-step device fabrication method. Importantly, the one-step device fabrication combines the high ion diffusion rate of [BSO₃]Py·HSO₄-doped polyaniline film, the high ionic conductivity of an ionic liquid electrolyte, and improved electrolyte wettability, providing an advanced device fabrication strategy for adaptive camouflage applications.