Solid Oxide Fuel Cells Using Novel Cathodes in the BaO-Co2O3-Fe2O3 Composited withGDC10

Most cathodes for SOFCs such as LSM, LSC, LSCF contain lanthanum oxide. In this study, cathode materials free from lanthanum oxide have been prepared. Compositions in the BaO-Y2O3-Fe2O3 and BaO-Y2O3-Co2O3-Fe2O3 have been obtained. Selected compositions with high electrical conductivities up to 60Scm-1 have been composited with GDC10 to form composite cathode with matching thermal expansion to GDC10. Symmetrical cells with GDC10 between the experimental cathodes, and small SOFCs with GDC10 as electrolyte, GDC10.NiO as anode and composite cathode have been constructed and evaluated up to 800oC. The electrical conductivity, thermal expansion, impedance and power densities have been studied. Power densities between 400-800oC have been obtained. The results are discussed in relation to the processing, microstructures, properties and performance of the solid oxide fuel cells.