Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 33: Solid-Liquid Interfaces III
O 33.1: Vortrag
Dienstag, 2. April 2019, 14:00–14:15, H10
Interaction of ethylene carbonate and lithium on thin cobalt oxide films - A model of the electrode|electrolyte interphase in Li-ion batteries — •Jihyun Kim1, Florian Buchner1, and R. Jürgen Behm1,2 — 1Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm, Germany — 2Helmholtz-Institute Ulm (HIU) Electrochemical Energy Storage, D-89081 Ulm, Germany
In this model study, we aim to get a molecular scale understanding of the initial stages of the formation of the electrolyte interphase (SEI) at the electrode|electrolyte interface, which plays a critical role in the performance of Li ion batteries (LIBs). Here, we report on the interaction of ethylene carbonate (EC, main electrolyte component in LIBs) with a thin film of CoO(111) grown on Ru(0001), which was investigated by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIRS) under UHV conditions. EC adsorbs molecularly intact on CoO(111) at 80 K and is stable below 200 K, while above 240 K EC decomposition is initiated. To mimic the electrolyte, 0.5 - 2 ML of Li was stepwise post-deposited on an EC adlayer at 80 K, which leads to EC decomposition most likely into Li- containing -C=O, -C-O-C-, -C-H species as well as Li2O2 or LiOH. For CoO anodes in LIBs, lithiation leads to a conversion reaction of CoO into Co0 as well as Li2O. However, for Li doses on EC adlayer at 80 K, we hardly observe such a reaction, indicating that Li directly interacts with EC. Only for Li doses on pristine CoO at 300 K, Co0 forms in the near surface regime. The results demonstrate the initial stage of the chemical SEI formation as well as the conversion of CoO.