New cobalt-free composites consisting of Ba0.5Sr0.5Fe0.9Ni0.1O3-δ （BSFN） and Ce0.8Sm0.2O2-δ （SDC） were investigated as possible cathode materials for intermediate-temperature solid oxide fuel cell （IT-SOFC）. B...New cobalt-free composites consisting of Ba0.5Sr0.5Fe0.9Ni0.1O3-δ （BSFN） and Ce0.8Sm0.2O2-δ （SDC） were investigated as possible cathode materials for intermediate-temperature solid oxide fuel cell （IT-SOFC）. BSFN, which was synthesized by auto ignition process, was chemically compatible with SDC up to 1100 ℃ as indicated by X-ray diffraction analysis. The electrical conductivity of BSFN reached the maximum value of 57 S.cm-1 at 450 ℃. The thermal expansion coefficient （TEC） value of BSFN was 30.9×10-6 K-1, much higher than that of typical electrolytes. The electrochemical behavior of the composites was analyzed via electrochemical impedance spectroscopy with symmetrical cells BSFN-SDC/SDC/BSFN-SDC. The area specific interracial polarization resistance （ASR） decreased with increasing SDC content of the composite. The area specific interracial polarization resistance （ASR） at 700 ℃ is only 0.49, 0.34 and 0.31 Ω.cm2 when 30, 40, and 50 wt% SDC was cooperated to BSFN, respectively. These results suggest that BSFN-SDC is a possible candidate for IT-SOFC cathode.展开更多
文摘New cobalt-free composites consisting of Ba0.5Sr0.5Fe0.9Ni0.1O3-δ （BSFN） and Ce0.8Sm0.2O2-δ （SDC） were investigated as possible cathode materials for intermediate-temperature solid oxide fuel cell （IT-SOFC）. BSFN, which was synthesized by auto ignition process, was chemically compatible with SDC up to 1100 ℃ as indicated by X-ray diffraction analysis. The electrical conductivity of BSFN reached the maximum value of 57 S.cm-1 at 450 ℃. The thermal expansion coefficient （TEC） value of BSFN was 30.9×10-6 K-1, much higher than that of typical electrolytes. The electrochemical behavior of the composites was analyzed via electrochemical impedance spectroscopy with symmetrical cells BSFN-SDC/SDC/BSFN-SDC. The area specific interracial polarization resistance （ASR） decreased with increasing SDC content of the composite. The area specific interracial polarization resistance （ASR） at 700 ℃ is only 0.49, 0.34 and 0.31 Ω.cm2 when 30, 40, and 50 wt% SDC was cooperated to BSFN, respectively. These results suggest that BSFN-SDC is a possible candidate for IT-SOFC cathode.
