Dynamic behavior of impurities and native components in model LSM microelectrodes on YSZ

Kion Norrman, Karin Vels Hansen, Torben Jacobsen

Research output: Contribution to journalJournal articleResearchpeer-review

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 languageEnglish
JournalR S C Advances
Volume5
Issue number106
Pages (from-to)87679-87693
Number of pages15
ISSN2046-2069
DOIs
Publication statusPublished - 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

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