Structure, Electrical and Oxygen Transport Properties of Fe-Doped SrCoO3—δ Perovskites

Abstract

The structure-property relationship of Fe-doped SrCoO 3−δ was studied. With increase of Fe content in SrCo 1−x Fe x O 3−δ from x=0 to x=0.2, the phase composition changed progressively in the order of hexagonal→brownmillerite (main)+hexagonal→cubic (main)+ brownmillerite→single cubic phase. Transition between the hexagonal/brownmillerite phase and the cubic phase took place with variation of the operating conditions, and was associated with remarkable changes in the electrical conductivity and oxygen permeation flux.

Electrochemical and Catalytic Properties of Fe-Doped SrCo0.9-xNb0.1FexO3-δCathode Materials

“…Cobalt-based perovskites, such as SrCo 0.8 Fe 0.2 O 3-δ (SCF), Sr 0.5 Sm 0.5 CoO 3-δ (SSC), and La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O 3-δ (LSCF), have been extensively investigated for ORR in IT-SOFC, [6][7][8][9][10][11][12][13] due to their high oxygen-ionic and electronic conductivities. The high temperature cubic phase of these SrCoO 3-δ shows very promising oxygen reduction catalytic properties, however above 900 • C this phase is structurally not stable, and exhibits drawbacks mainly through large thermal expansion coefficients and high reactivity with yttria-stabilized zirconia electrolytes.…”