Probing Ionic Liquid/Electrode Interfaces by Hyperspectral Imaging

Abstract

We will present data for experiments that probe structure and dynamics at ionic liquid (IL) and ionic liquid-based (IL-based) systems with electrode interfaces. IL-based electrolytes have been investigated for applications ranging from energy conversion devices (e.g., capacitors, batteries, fuel cells, and solar cells) to sensors. Fundamental characterizations of IL-based electrolyte/electrode systems can contribute toward engineered progress for these enterprises since adsorbed species and their associated interfacial dynamics play critical roles in determining device efficiencies. Our studies utilize surface enhanced infrared absorption (SEIRA) spectroscopy. In particular, we demonstrate hyperspectral imaging at an attenuated total reflectance crystal that has been modified with a nanostructured gold electrode. Imaging experiments characterize interfacial structure and dynamics between several ionic liquid media (compositions) at the electrode surface simultaneously during electrochemical perturbation. Our initial spectral imaging studies explore ILs composed of imidazolium-based cations with alkylsulfate, tetrafluoroborate, thiocyanate, dicyanamide, and bis(trifluoromethylsulfonyl)imide anions.