[Paper] Investigation of Electrolyte Species on Color Properties of an Electrochromic Device Featuring a Hybrid Capacitor Architecture

Abstract

We have demonstrated a multicolor electrochromic device (ECD) with a novel architecture. Different typical ECDs featuring commonly two flat transparent electrodes, a double electrical layer electrode is applied to the device as the counter electrode. By this architecture, even two EC molecules with different polarities mixed in the same ECD can display their unique color, respectively. This paper reports the effect of several commonly-used quaternary ammonium salts as electrolytes on color properties of the ECD featuring a hybrid capacitor architecture. The aim is to select the suitable electrolyte to fabricate multicolor ECD with excellent color performance. Among them, the electrolyte tetraethylammonium tetrafluoroborate performs most satisfactorily attributed to its small ion size and high conductivity. This novel, easily-fabricated, and high EC performance multicolor device provides an opportunity that will develop color ECDs and expand the potential of EC technology.