Cobalt-free Composite Ba_0.5Sr_0.5Fe_0.9Ni_0.1O_3-δ-Ce_0.8Sm_0.2O_2-δ as Cathode for Intermediate-Temperature Solid Oxide Fuel Cell

Xiangfeng Chu 1) , Feng Liu 1) , Weichang Zhu 2) , Yongping Dong 1) , Mingfu Ye 1) and Wenqi Sun 1) 1) School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002, China 2) School of Materials Science and Engineering, Anhui University of Technology, Maanshan 243002, China

摘 要：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 30.9×10-6K-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 interfacial polarization resistance （ASR） decreased with increasing SDC content of the composite. The area specific interfacial 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.

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