Time-dependent performance changes in LSCF-infiltrated SOFC cathodes: The role of nano-particle coarsening

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119 Scopus citations

Abstract

Symmetric solid oxide cells with Gd doped ceria (GDC) electrolytes and La0.6Sr0.4Co0.2Fe0.8O 3 -δ (LSCF)-infiltrated-GDC cathodes were maintained in air with no current at temperatures from 650 to 850 °C. Comparison of SEM images before and after aging showed inhomogeneous coarsening of LSCF nano-particles in the cathodes. The polarization resistance, measured periodically at 600 °C using electrochemical impedance spectroscopy, increased at a higher rate with increasing aging temperature. The resistance variation was fit using a model that relates resistance to time-dependent LSCF surface area, based on surface diffusion limited coarsening. Good agreement with the experimental data is obtained for a limited range of fitting parameters. The model predicts that the cathode resistance should increase from ~ 0.2 to 0.28-0.35 Ω cm 2, if maintained at the operating temperature of 600 °C for 40,000 h.

Original languageEnglish (US)
Pages (from-to)64-67
Number of pages4
JournalSolid State Ionics
Volume187
Issue number1
DOIs
StatePublished - Apr 8 2011

Keywords

  • Cathode
  • Coarsening
  • Degradation
  • Infiltration
  • SOFC
  • Stability

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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