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Photoelectron spectroscopic study of Li intercalation into V2O5 thin films

Wu, Qi-Hui ; Thißen, Andreas ; Jaegermann, Wolfram (2005)
Photoelectron spectroscopic study of Li intercalation into V2O5 thin films.
In: Surface Science, 578 (1-3)
doi: 10.1016/j.susc.2005.01.042
Artikel, Bibliographie

Kurzbeschreibung (Abstract)

In this work the intercalation of lithium into V2O5 thin films prepared by physical vapor deposition (PVD) on highly oriented pyrolytic graphite (HOPG) substrates is studied by X-ray and UV induced photoelectron spectroscopy (XPS and UPS). The vanadium ions in the as-prepared V2O5 are mostly in a pentavalent V5+ state. The intercalated lithium strongly affects the electronic structure and causes a Fermi level shift of about 0.5 eV. The core level spectra show that the vanadium gets partially reduced to V4+ and even V3+ states. About 0.32 electrons per intercalated lithium atom are transferred from the Li2s-orbitals into V3d-like states. For a completely lithium-intercalated V2O5 film with a composition of LizV2O5 (z ≈ 2.4) a further increase in deposition time leads to lithium adsorption on the V2O5 surface and thus to the formation of lithium oxides (LixOy). Partially the vanadium gets reduced even further to V2+ and V1+ states indicating a decomposition reaction. The work function decreases with increasing lithium deposition time due to lithium intercalation into the V2O5, as well as to the lithium adsorption accompanied by the formation of surface dipoles and finally slightly increases again because of depolarization effects.

Typ des Eintrags: Artikel
Erschienen: 2005
Autor(en): Wu, Qi-Hui ; Thißen, Andreas ; Jaegermann, Wolfram
Art des Eintrags: Bibliographie
Titel: Photoelectron spectroscopic study of Li intercalation into V2O5 thin films
Sprache: Englisch
Publikationsjahr: März 2005
Titel der Zeitschrift, Zeitung oder Schriftenreihe: Surface Science
Jahrgang/Volume einer Zeitschrift: 578
(Heft-)Nummer: 1-3
DOI: 10.1016/j.susc.2005.01.042
Kurzbeschreibung (Abstract):

In this work the intercalation of lithium into V2O5 thin films prepared by physical vapor deposition (PVD) on highly oriented pyrolytic graphite (HOPG) substrates is studied by X-ray and UV induced photoelectron spectroscopy (XPS and UPS). The vanadium ions in the as-prepared V2O5 are mostly in a pentavalent V5+ state. The intercalated lithium strongly affects the electronic structure and causes a Fermi level shift of about 0.5 eV. The core level spectra show that the vanadium gets partially reduced to V4+ and even V3+ states. About 0.32 electrons per intercalated lithium atom are transferred from the Li2s-orbitals into V3d-like states. For a completely lithium-intercalated V2O5 film with a composition of LizV2O5 (z ≈ 2.4) a further increase in deposition time leads to lithium adsorption on the V2O5 surface and thus to the formation of lithium oxides (LixOy). Partially the vanadium gets reduced even further to V2+ and V1+ states indicating a decomposition reaction. The work function decreases with increasing lithium deposition time due to lithium intercalation into the V2O5, as well as to the lithium adsorption accompanied by the formation of surface dipoles and finally slightly increases again because of depolarization effects.

Freie Schlagworte: Vanadium pentoxide; Lithium intercalation; Cathode materials; Intercalation batteries; PES
Zusätzliche Informationen:

SFB 595 A3

Fachbereich(e)/-gebiet(e): 11 Fachbereich Material- und Geowissenschaften
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft
11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Oberflächenforschung
DFG-Sonderforschungsbereiche (inkl. Transregio)
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche
Zentrale Einrichtungen
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > A - Synthese
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 595: Elektrische Ermüdung > A - Synthese > Teilprojekt A3: Grenzflächen und dünne Schichten von Ionenleitern: Elektronische Struktur, elektrochemische Potentiale, Defektbildung und Degradationsmechanismen
Hinterlegungsdatum: 04 Aug 2011 09:36
Letzte Änderung: 29 Jan 2019 09:26
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