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Optimized La 0.6 Sr 0.4 CoO 3– δ Thin‐Film Electrodes with Extremely Fast Oxygen‐Reduction Kinetics
Author(s) -
Januschewsky Judith,
Ahrens Martin,
Opitz Alexander,
Kubel Frank,
Fleig Jürgen
Publication year - 2009
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200900362
Subject(s) - materials science , yttria stabilized zirconia , amorphous solid , electrode , crystallinity , electrochemistry , polarization (electrochemistry) , pulsed laser deposition , thin film , cathode , analytical chemistry (journal) , cubic zirconia , oxide , deposition (geology) , oxygen , chemical engineering , nanotechnology , composite material , crystallography , metallurgy , chemistry , ceramic , paleontology , chromatography , sediment , engineering , biology , organic chemistry
La 0.6 Sr 0.4 CoO 3– δ (LSC) thin‐film electrodes are prepared on yttria‐stabilized zirconia (YSZ) substrates by pulsed laser deposition at different deposition temperatures. The decrease of the film crystallinity, occurring when the deposition temperature is lowered, is accompanied by a strong increase of the electrochemical oxygen exchange rate of LSC. For more or less X‐ray diffraction (XRD)‐amorphous electrodes deposited between ca. 340 and 510 °C polarization resistances as low as 0.1 Ω cm 2 can be obtained at 600 °C. Such films also exhibit the best stability of the polarization resistance while electrodes deposited at higher temperatures show a strong and fast degradation of the electrochemical kinetics (thermal deactivation). Possible reasons for this behavior and consequences with respect to the preparation of high‐performance solid oxide fuel cell (SOFC) cathodes are discussed.