Investigation of PO43- oxyanion-doping on the properties of CaFe0.4Ti0.6O3−δ for potential application as symmetrical electrodes for SOFCs

Research output: Contribution to journalArticle

Authors

  • Lucía dos Santos-Gómez
  • Jose Porras-Vázquez
  • Enrique Losilla
  • David Marrero-López
  • Peter Slater

Colleges, School and Institutes

Abstract

CaTi0.6-xFe0.4PxO3-δ (0≤x ≤ 0.75) perovskite series are investigated as potential symmetrical electrodes for SOFCs. Pure phase compounds with a cubic perovskite structure (s.g. Pm3̅m ) are obtained for x ≤ 0.025, while higher doping level leads to the formation of Ca10(PO4)6(OH)2 as secondary phase. The P-doped compounds are structurally stable under reducing atmosphere unlike the undoped phase. Conductivity values of the P-doped samples are slightly higher than that of the undoped one, i.e. 0.11 and 0.07 Scm−1 for CaTi0.575Fe0.4P0.025O3-δ and CaTi0.6Fe0.4O3-δ, respectively, at 750 °C in air. The performance of CaTi0.575Fe0.4P0.025O3-δ acting simultaneously as both anode and cathode was also tested in a symmetrical solid oxide fuel cell with a 240 μm thick YSZ electrolyte. Hence, these results show that PO43- units can be introduced into CaTi0.6Fe0.4O3-δ perovskite structure, having beneficial effects on the electrochemical performance and the phase stability.

Details

Original languageEnglish
Article number155437
JournalJournal of Alloys and Compounds
Volume835
Early online date30 Apr 2020
Publication statusE-pub ahead of print - 30 Apr 2020

Keywords

  • Calcium titanates, Oxyanion doping, Phosphate, Symmetrical solid oxide fuel cell