Dresden 2017 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 108: Graphene: Adsorption, Intercalation and Other Aspects
O 108.10: Vortrag
Freitag, 24. März 2017, 12:45–13:00, TRE Ma
Intercalation and Deintercalation of Lithium at the Ionic Liquid|Graphite(0001) Interface — •Florian Buchner1, Jihyun Kim2, Christiane Adler2, Joachim Bansmann2, and R. Jürgen Behm1,2 — 1Helmholtz-Institute Ulm (HIU) Electrochemical Energy Storage, D-89081 Ulm, Germany — 2Ulm University, Institute of Surface Chemistry and Catalysis, D-89069 Ulm, Germany
The intercalation and deintercalation of lithium (Li) on the graphite anode in Li-ion batteries is essential for their function. This was investigated in a model study under ultrahigh vacuum conditions as a function of temperature employing X-ray and UV photoelectron spectroscopy (XPS / UPS). After vapor deposition of metallic Li, partially charged Liδ + atoms were identified on graphite(0001) at 80 K, while, they diffuse into the bulk at 300 K. Interestingly, the ionic liquid (IL) 1-butyl-1-methyl-pyrrolidinium bis-(trifluoromethylsulfonyl)amide [BMP][TFSA], which is a promising solvent/electrolyte, can be used as a probe to measure Liδ + deintercalation. After adsorption of a [BMP][TFSA] (sub-)monolayer on lithiated graphite at 80 K, the sample was heated to 300 K. Both the gradual shifts of all adsorbate-related XP peaks at > 230 K and the simultaneous lowering of the work function indicate the accumulation of partially charged Liδ + atoms at the IL|graphite(0001) interface. This is accompanied by a partial decomposition of the IL adlayer (LiF, Li2S, and LiN3, etc.), which we associate with the initial stages of the chemical formation of the electrode|electrolyte interface (EEI), which in turn is crucial for the function of batteries.