Abstract
Strontium-doped lanthanum manganite is a widely used cathode material in solid oxide fuel cells. Segregation phenomena can have a critical impact on performance and durability, especially when they cause active interfaces to degrade. The segregation behavior in polarized and non-polarized strontium-doped lanthanum manganite ((La0.75Sr0.25)0.95MnO3) microelectrodes with a diameter of 100 μm and a thickness of ∼500 nm on an yttria-stabilized zirconia electrolyte were analyzed post-mortem after ∼200 h at temperatures up to 850 °C. Time-of-flight secondary ion mass spectrometry was used to study the dynamic behavior of the native components (La, Sr, Mn) and selected impurities (Si, K, Na) both laterally and in-depth. Manganese was found to be especially mobile and showed both segregation onto the electrolyte as a result of temperature and polarization and dissolution into the electrolyte below the microelectrodes. All native components showed a complex in-depth dynamic behavior, and a nanoscale in-depth analysis of the electrode-electrolyte interface revealed the formation of a well-defined lanthanum zirconate layer. The selected impurities segregated to the electrolyte and microelectrode surfaces and Na- and K-rich layers formed at different depths.
Original language | English |
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Journal | R S C Advances |
Volume | 5 |
Issue number | 106 |
Pages (from-to) | 87679-87693 |
Number of pages | 15 |
ISSN | 2046-2069 |
DOIs | |
Publication status | Published - 2015 |
Keywords
- Chemical Engineering (all)
- Chemistry (all)
- Cathodes
- Electrodes
- Electrolytes
- Fuel cells
- Lanthanum
- Lanthanum compounds
- Lanthanum oxides
- Manganese
- Manganese oxide
- Manganites
- Mass spectrometry
- Microelectrodes
- Secondary ion mass spectrometry
- Segregation (metallography)
- Solid electrolytes
- Solid oxide fuel cells (SOFC)
- Strontium
- Zirconia
- Cath-ode materials
- Electrode-electrolyte interfaces
- Lanthanum zirconate
- Microelectrode surfaces
- Segregation phenomena
- Strontium doped lanthanum manganites
- Time of flight secondary ion mass spectrometry
- Yttria stabilized zirconia electrolyte
- Yttria stabilized zirconia