Ag-perovskite cermets for thin film solid oxide fuel cell air-electrode applications

L. S. Wang, Scott A Barnett*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

60 Scopus citations

Abstract

Ag-(La0.7Sr0.3)CoO3 (LSC) and Ag-(La0.7Sr0.3)MnO3 (LSM) cermet thin films have been deposited by dc magnetron cosputtering from Ag and LSC or LSM targets. The cermets have potential applications as high-conductivity air electrode materials for solid-oxide fuel cells operating at low enough temperatures (≤ 750 °C) that Ag volatility is not a problem. The resistivity ρ at 750 °C in air of Ag-LSC films decreased with increasing Ag volume fraction fAg, from 1.6 × 10-2Ω cm for pure LSC to 8 × 10-4 for fAg = 0.3 to 1 × 10-5Ω cm for pure Ag. The interfacial resistance ri of the electrodes on (Y2O3)0.25(Bi2O3)0.75 (YSB) electrolytes was measured using ac impedance spectroscopy over a range of temperatures and oxygen partial pressures. For Ag-LSC on YSB measured at 750 °C in air, ri decreased from 0.4 for pure LSC to a minimum of 0.3 Ω cm2 at fAg = 0.3, and increased to 1.5 Ω cm2 for pure Ag. Increasing fAg in Ag-LSM from 0 to 0.3 decreased ri from 0.7 to 0.5 Ω cm2 under these conditions. Ag-LSC electrodes with porous LSC cap layers exhibited no observable Ag segregation, evaporation, or change in interface resistance during 200 h annealing at 750 °C.

Original languageEnglish (US)
Pages (from-to)103-113
Number of pages11
JournalSolid State Ionics
Volume76
Issue number1-2
DOIs
StatePublished - Jan 1 1995

Keywords

  • Cermet
  • Cobalt oxide
  • Fuel cell
  • Ionic conductivity - oxygen
  • Manganese oxide

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrochemistry
  • Physical and Theoretical Chemistry
  • Energy Engineering and Power Technology
  • Materials Chemistry

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