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<div class="csl-entry">Januschewsky, J. (2010). <i>Investigations on structure-property relations of (La,Sr)CoO3-[delta] thin film SOFC cathodes</i> [Dissertation, Technische Universität Wien]. reposiTUm. https://resolver.obvsg.at/urn:nbn:at:at-ubtuw:1-44459</div>
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In this thesis (La,Sr)CoO3-d thin films were prepared by PLD and a simple sol-gel route. The electrochemical performance towards oxygen reduction was investigated by impedance spectroscopy. Structural and morphological investigations were performed using XRD, SEM, AFM and TEM.<br />The surface composition was investigated by LEIS and XPS. From that data several structure-property relations were found.<br />The structure and electrochemical performance of (La,Sr)CoO3-d thin-film electrodes prepared by PLD on single crystalline YSZ strongly depends on the deposition temperature of the films. Surprisingly thin films deposited at rather low temperatures (340-510°C) and exhibiting hardly any signal in Bragg-Brentano XRD patterns showed the best electrochemical performance. It was possible to prepare LSC film electrodes with polarization resistances as low as 0.1 Ohmcm² at 600°C.<br />Many electrodes showed a pronounced degradation when operating between 500 and 700°C. Interestingly, the films exhibiting the lowest resistances showed the lowest degradation within a few days of operation. It was further possible to employ a sol-gel route to prepare electrodes with the same performance as the electrodes prepared by PLD. Again it seems that there is a correlation between the degree of crystallinity and the resistance. As the sol-gel thin films are smooth and dense and have no open porosity this extremely fast oxygen reduction cannot be attributed to a strongly increased surface area. It seems to be related to the lower crystallinity or a consequence of the lower crystallinity. The surface composition was investigated by LEIS and XPS. Different results concerning the surface composition of as prepared and heat treated samples deposited at 450°C and 650°C are achieved.
en
dc.language
English
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dc.language.iso
en
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dc.rights.uri
http://rightsstatements.org/vocab/InC/1.0/
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dc.subject
SOFC
de
dc.subject
Brennstoffzelle
de
dc.subject
LSC
de
dc.subject
Kathode
de
dc.subject
Dünnfilm
de
dc.subject
SOFC
en
dc.subject
Fuel cell
en
dc.subject
Lanthanum cobaltite
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dc.subject
LSC
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dc.subject
Cathode
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dc.subject
Thin film
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dc.title
Investigations on structure-property relations of (La,Sr)CoO3-[delta] thin film SOFC cathodes
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dc.type
Thesis
en
dc.type
Hochschulschrift
de
dc.rights.license
In Copyright
en
dc.rights.license
Urheberrechtsschutz
de
dc.contributor.affiliation
TU Wien, Österreich
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dc.rights.holder
Judith Januschewsky
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tuw.version
vor
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tuw.thesisinformation
Technische Universität Wien
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tuw.publication.orgunit
E164 - Institut für Chemische Technologien und Analytik