Performance of SrSc0.2Co0.8O3-d + Sm0.5Sr0.5CoO3-d mixed-conducting composite electrodes for oxygen reduction at intermediate temperatures
MetadataShow full item record
In order to improve the electrical conductivity of the SrSc0.2Co0.8O3-d (SrScCo) electrode, a composite of 70 wt% SrSc0.2Co0.8O3-d and 30 wt% Sm0.5Sr0.5CoO3-d (SrScCo + SmSrCo) was prepared and investigated for electrochemical oxygen reduction at intermediate temperatures. The phase reaction between SrScCo and SmSrCo and its effect on the electrical conductivity, oxygen vacancy concentration and oxygen mobility were examined by XRD, 4-probe DC conductivity measurement, iodometry titration and O2-TPD experiment, respectively. The results showed that the composite reached a maximum conductivity around 123 S cm-1 at 600 °C, nearly five times that of SrScCo. AC impedance results showed that the electron charge-transfer process was greatly improved by forming the composite electrode, while the oxygen-ion charge-transfer process was somewhat deteriorated. By firing at 1000 °C for 2 h, a SOFC with the SrScCo + SmSrCo cathode and thin-film SDC electrolyte delivered peak power densities of 1100 and 366 mW cm-2 at 600 and 500 °C, respectively, which were only modestly lower than those of a similar cell with a pure SrScCo cathode. © 2009 Professor T. Nejat Veziroglu.
Showing items related by title, author, creator and subject.
Cobalt-free niobium-doped barium ferrite as potential materials of dense ceramic membranes for oxygen separationXu, D.; Dong, F.; Chen, Y.; Zhao, B.; Liu, Shaomin; Tade, Moses; Shao, Zongping (2014)Cobalt-free perovskite-type oxides with the nominal composition of BaNbyFe1−yO3−δ (y=0.025–0.20) are synthesized and evaluated as materials used in ceramic membranes for oxygen separation. The effects of Nb-doping on the ...
A Comparative Study of the Performance of SrCo0.76Fe0.19Al0.1Ox and (SrCo0.8Fe0.2O3-deltda)0.95(SrAl2O4)0.05 Mixed-Conducting MembranesZhu, N.; Zhang, G.; Liu, Z.; Dong, X.; Jin, W.; Liu, Shaomin (2013)Dense oxygen permeable ceramic membranes are promising materials for separating oxygen from air and for syngas production. The crystal structure, oxygen vacancy, microstructure, thermal expansion behavior, electrical ...
Chen, D.; Chen, C.; Zhang, Z.; Baiyee, Z.; Ciucci, F.; Shao, Zongping (2015)Mixed conducting perovskite oxides are promising catalysts for high-temperature oxygen reduction reaction. Pristine SrCoO3−δ is a widely used parent oxide for the development of highly active mixed conductors. Doping a ...