Baumann, F. S., Maier, J., & Fleig, J. (2008). The polarization resistance of mixed conducting SOFC cathodes: A comparative study using thin film model electrodes. Solid State Ionics, 179(21–26), 1198–1204. https://doi.org/10.1016/j.ssi.2008.02.059
Condensed Matter Physics; General Materials Science; General Chemistry
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Abstract:
The oxygen reduction reaction on YSZ solid electrolytes is investigated by means of thin film microelectrodes employing perovskite-type mixed conductors such as La0.6Sr0.4Co0.8Fe0.2O3 − δ, Ba0.5Sr0.5Co0.8Fe0.2O3 − δ and Sm0.5Sr0.5CoO3 − δ as electrode materials. Owing to the simple geometry of the circular microelectrodes direct comparison of electrochemical material parameters is possible and reveals that the Fe/Co ratio in La0.6Sr0.4Co1 − xFexO3 − δ has only little effect on the resistance associated with the surface oxygen exchange. Ba0.5Sr0.5Co0.8Fe0.2O3 − δ thin films exhibit very low surface-related polarization resistances. Strongly decreased resistances can also be observed in Co-rich La0.6Sr0.4Co1 − xFexO3 − δ electrodes after a cathodic voltage pulse treatment of several tens of seconds. Area-related surface resistances below 0.1 Ωcm2 at 700 °C can be achieved by such activation. Further phenomena associated with this voltage activation are discussed.
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Research Areas:
Climate Neutral, Renewable and Conventional Energy Supply Systems: 20% Structure-Property Relationship: 20% Non-metallic Materials: 40% Surfaces and Interfaces: 20%
