Wu, Qi-Hui ; Thißen, Andreas ; Jaegermann, Wolfram (2004)
Photoelectron spectroscopic study of Na intercalation into V2O5 thin films.
In: Solid State Ionics, 167 (1-2)
doi: 10.1016/j.ssi.2003.12.016
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
In this work, the intercalation of sodium 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 sodium strongly affects the electronic structure and causes a Fermi level shift of about 0.7 eV. The core level spectra show that the vanadium gets partially reduced to V4+ and even V3+ states. About 0.42 electrons per intercalated sodium atom are transferred from the Na3s orbitals into V3d-like states. For a completely sodium-intercalated V2O5 film with a composition of NaxV2O5 (x≈2), a further increase in deposition time leads to sodium adsorption on the V2O5 surface and thus to the formation of sodium oxides (NaxOy) and, finally, also metallic sodium at the sample surface. Partially, the vanadium gets reduced even further to V2+ and V1+ states indicating a decomposition reaction. The work function decreases with increasing sodium deposition time due to sodium intercalation into the V2O5, as well as to the sodium adsorption accompanied by the formation of surface dipoles and finally increases again because of depolarization effects and the formation of a metallic sodium phase on the surface.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2004 |
| Autor(en): | Wu, Qi-Hui ; Thißen, Andreas ; Jaegermann, Wolfram |
| Art des Eintrags: | Bibliographie |
| Titel: | Photoelectron spectroscopic study of Na intercalation into V2O5 thin films |
| Sprache: | Englisch |
| Publikationsjahr: | Februar 2004 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Solid State Ionics |
| Jahrgang/Volume einer Zeitschrift: | 167 |
| (Heft-)Nummer: | 1-2 |
| DOI: | 10.1016/j.ssi.2003.12.016 |
| Kurzbeschreibung (Abstract): | In this work, the intercalation of sodium 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 sodium strongly affects the electronic structure and causes a Fermi level shift of about 0.7 eV. The core level spectra show that the vanadium gets partially reduced to V4+ and even V3+ states. About 0.42 electrons per intercalated sodium atom are transferred from the Na3s orbitals into V3d-like states. For a completely sodium-intercalated V2O5 film with a composition of NaxV2O5 (x≈2), a further increase in deposition time leads to sodium adsorption on the V2O5 surface and thus to the formation of sodium oxides (NaxOy) and, finally, also metallic sodium at the sample surface. Partially, the vanadium gets reduced even further to V2+ and V1+ states indicating a decomposition reaction. The work function decreases with increasing sodium deposition time due to sodium intercalation into the V2O5, as well as to the sodium adsorption accompanied by the formation of surface dipoles and finally increases again because of depolarization effects and the formation of a metallic sodium phase on the surface. |
| Freie Schlagworte: | Vanadium pentoxide; Sodium 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 09:42 |
| Letzte Änderung: | 26 Aug 2018 21:26 |
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