Dresden 2017 – wissenschaftliches Programm
CPP 61.3: Vortrag
Donnerstag, 23. März 2017, 15:30–15:45, ZEU 114
Surface composition of a binary system "Ionic Liquid/Lithium Salt", investigated by photoelectron spectroscopy — •Fabian Ullmann1, Anna Dimitrova1, Marcel Himmerlich1, Oliver Höfft2, Frank Endres2, and Stefan Krischok1 — 1Institut für Physik & IMN MacroNano, Technische Universität Ilmenau, Germany — 2Institut für Elektrochemie, Technische Universität Clausthal, Germany
Since a decade, the binary systems Ionic-Liquids (ILs)/lithium-salt are widely used media in electrochemistry. They were shown to be an important component in electrolytes for Li-ion batteries, and it is already demonstrated that a number of refractory metals are successfully deposited in ILs only in the presence of Li+. In order to control the electrochemical processes, an understanding of molecular and ionic interactions, which occur prior the electrochemical reduction, is required and the influence of side reactions of the electrolyte with the ambient atmosphere has to be known. To this end Photoelectron spectroscopy in ultra-high vacuum (UHV) is a powerful tool, being accessible to the very low vapor pressure of many ILs. In this study we use two ionic liquids with a common anionic part: [Py1,4][Tf2N] and [EMIm][Tf2N], in which Li[Tf2N] was dissolved in different quantities. The surface composition of these binary mixtures was studied both (i) for samples handled and transported to the UHV chamber solely under inert atmosphere and (ii) for those exposed to air before introducing them into the measurement system.