An electrochromic ionic liquid: design, characterization, and performance in a solid-state platform

ACS Appl Mater Interfaces. 2013 Jan;5(1):55-62. doi: 10.1021/am3018948. Epub 2012 Dec 14.

Abstract

This work describes the synthesis and characteristics of a novel electrochromic ionic liquid (IL) based on a phosphonium core tethered to a viologen moiety. When integrated into a solid-state electrochromic platform, the viologen modified IL behaved as both the electrolyte and the electrochromic material. Platform fabrication was achieved through in situ photo-polymerization and encapsulation of this novel IL within a hybrid sol-gel. Important parameters of the platform performance, including its coloration efficiency, switching kinetics, and optical properties were characterised using UV-vis spectroscopy and cyclic voltammetry in tandem. The electrochromic platform exhibits a coloration efficiency of 10.72 cm(2) C(-1) and a varied optical output as a function of the incident current. Despite the rather viscous nature of the material, the platform exhibited approximately 2 orders of magnitude faster switching kinetics (221 s to reach 95 % absorbance) when compared to previously reported electrochromic ILs (18,000 s).

Publication types

  • Research Support, Non-U.S. Gov't