elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Datenschutz | Kontakt | English
Schriftgröße: [-] Text [+]

Sprayed and Constrained-Sintered Zirconia Based Electrolytes

Christenn, Claudia und Ansar, Syed Asif (2008) Sprayed and Constrained-Sintered Zirconia Based Electrolytes. 8th European Solid Oxide Fuel Cell Forum, 2008-06-30 - 2008-07-04, Luzern (Schweiz).

[img]
Vorschau
PDF
203kB

Kurzfassung

The current development in solid oxide fuel cells (SOFCs) is focused on reducing the operating temperature below 800 °C. Though, the reduced operating temperature promotes durability of cells and decreases stringent demands on peripheral components, the ionic conductivity of electrolytes decreases following Arrhenius law. To solve this problem two different ways are possible: a) reducing the thickness of the conventionally used yttria-stabilized zirconia (YSZ) electrolyte by using nanostructured particles as feedstock or b) by using an electrolyte with improved ionic conductivity for intermediate temperature (IT)-SOFCs. Conventional sintering of electrolytes is performed over several hours at temperatures above 1400 °C. In this paper, plasma sprayed YSZ electrolyte layers were sintered under constraint and non-constraint conditions in the temperature range of 800 to 1520 °C. Thereby, the influence of particle size on sintering kinetics and microstructure development was analysed. By comparison of nanostructured YSZ and conventional YSZ layers, differences in the sintering rate were determined. Lower dL/L0 of nanostructured compared to conventional plasma sprayed YSZ during heating above 900 °C was measured, indicating initiation of densification at lower temperature compared to conventional YSZ. A higher shrinkage rate of the nanostructured YSZ layer strongly suggests that observed differences in sintering rates are due to different particle sizes of the powder feedstock. Experimental shrinkage rates were assigned to different mass transfer effects according to the sintering model of Coble. It was observed that the sintering of free-standing coatings differ from that of coatings on substrates which was explained by theory of constrained sintering. Changes of the microstructural characteristics were identified using scanning electron microscopy. According to the constraint from the substrate, the YSZ<sub>nano</sub> sample constrained sintered at 1000 °C has achieved a lower thickness compared to the free-standing sample sintered at 1520 °C. Comparing the values of both YSZ electrolytes sintered at 1325 °C to the ones of the as-sprayed layers, a faster sintering process of the nanostructured YSZ can be supposed. The lamellar microstructure in the as-sprayed samples was found to significantly reduce the electrical conductivity of the YSZ electrolytes, measured by 4-point dc method. Sintering of as-sprayed electrolyte layers at sufficient temperature increased the electrical conductivity, due to changes of the microstructure densification.

elib-URL des Eintrags:https://elib.dlr.de/55975/
Dokumentart:Konferenzbeitrag (Poster)
Titel:Sprayed and Constrained-Sintered Zirconia Based Electrolytes
Autoren:
AutorenInstitution oder E-Mail-AdresseAutoren-ORCID-iDORCID Put Code
Christenn, ClaudiaNICHT SPEZIFIZIERTNICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Ansar, Syed AsifNICHT SPEZIFIZIERTNICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Datum:30 Juni 2008
Referierte Publikation:Nein
Open Access:Ja
Gold Open Access:Nein
In SCOPUS:Nein
In ISI Web of Science:Nein
Herausgeber:
HerausgeberInstitution und/oder E-Mail-Adresse der HerausgeberHerausgeber-ORCID-iDORCID Put Code
European Fuel Cell Forum, NICHT SPEZIFIZIERTNICHT SPEZIFIZIERTNICHT SPEZIFIZIERT
Name der Reihe:Conference Proceedings
Status:veröffentlicht
Stichwörter:Solid oxide fuel cell, Plasma spraying, Sintering, Yttria stabilized Zirconia,
Veranstaltungstitel:8th European Solid Oxide Fuel Cell Forum
Veranstaltungsort:Luzern (Schweiz)
Veranstaltungsart:internationale Konferenz
Veranstaltungsbeginn:30 Juni 2008
Veranstaltungsende:4 Juli 2008
Veranstalter :Eurpoean Fuel Cell Forum
HGF - Forschungsbereich:Energie
HGF - Programm:Rationelle Energieumwandlung (alt)
HGF - Programmthema:E BZ - Brennstoffzellen (alt)
DLR - Schwerpunkt:Energie
DLR - Forschungsgebiet:E BZ - Brennstoffzellen
DLR - Teilgebiet (Projekt, Vorhaben):E - Hochtemperatur-Brennstoffzellen (alt)
Standort: Stuttgart
Institute & Einrichtungen:Institut für Technische Thermodynamik > Elektrochemische Energietechnik
Hinterlegt von: Christenn, Claudia
Hinterlegt am:17 Mär 2009
Letzte Änderung:24 Apr 2024 19:20

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Blättern
Suchen
Hilfe & Kontakt
Informationen
electronic library verwendet EPrints 3.3.12
Gestaltung Webseite und Datenbank: Copyright © Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.