Materials Chemistry and Physics, Vol.180, 256-262, 2016
Cobalt-free perovskite Pr0.5Sr0.5Fe1-xCuxO3-delta (PSFC) as a cathode material for intermediate temperature solid oxide fuel cells
PSFC (Pr0.5Sr0.5Fe1-xCuxO3-delta) is a new perovskite-type oxide that has gained considerable attention as cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs), due to its high mixed ionic-electronic conductivity below 800 degrees C. In this work, PSFC (Pr0.5Sr0.5Fe1-xCuxO3-delta, x = 0.2 and 0.4) powders were synthesized by the citrate method and structurally characterized by X-ray diffractometry. Screen-printed cathodes were sintered at 1050 degrees C and electrochemically characterized by impedance spectroscopy at 600-800 degrees C in pure oxygen. The area specific resistances (ASR) of the Pr0.5Sr0.5Fe1-xCuxO3-delta material are shown to be competitive with typical values reported for cobalt based cathodes in the measured temperature range, while, importantly, offering a significantly lower activation energy, 0.62 eV. The thermal expansion coefficients of these Co-free cathodes are in the range of 13-15 x 10(-6) degrees C-1, in a temperature range 200-650 degrees C, demonstrating a good thermal compatibility with gadolinia doped ceria (CGO) electrolytes. (C) 2016 Elsevier B.V. All rights reserved.