Structural and electrochemical properties of Pr0.3Sr0.7Co0.3Fe0.7O3−δ cathode for IT-SOFC

Abstract

The electrochemical properties and microstructure changes of Pr0.3Sr0.7Co0.3Fe0.7O3−δ (PSCF3737) were studied in this paper. It was confirmed through X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis that the oxygen vacancy of PSCF3737 was lower and that the atomic distance between an oxygen atom and a neighboring atom (especially cobalt) of PSCF3737 was longer compared to those of Pr0.3Sr0.7CoO3 − δ (PSC37). In addition, the surface reaction of PSCF3737 changed from a one-electron reduction mechanism to a two-electron reduction mechanism, which may lead to enhancement of the cathode performance. The area specific resistance of PSCF3737 was 0.11 Ω cm2 at 700 °C after changing the fabrication conditions of the cathode in order to optimize the microstructure. A single cell test was performed using PSCF3737. A maximum power density of 315 mW/cm2 at 575 °C was obtained.