Characterization and Comparison of Different Cathode Materials for SC-SOFC: LSM, BSCF, SSC, and LSCF

Four cathode materials for single chamber solid oxide fuel cell (SC-SOFC) [La0.8Sr0.2MnO3d (LSM), Ba0.5Sr0.5Co0.8Fe0.2O3d (BSCF), Sm0.5Sr0.5CoO3d (SSC), and La0.6Sr0.4Co0.2Fe0.8O3d (LSCF)] were investigated regarding their chemical stability, electrical conductivity, catalytic activity, and polarization resistance under air and methane/air atmosphere. Electrolyte-supported fuel cells, with Ce0.9Gd0.1O2d (CGO) electrolyte and a Ni-CGO anode, were tested in several methane/air mixtures with each cathode materials between 625 and 725 degrees C. These single cells were not optimized but only designed to compare the four studied cathodes. The decrease of methane-to-oxygen ratio from 2 to 0.67 strongly increased the performance of fuel cells for all cathode materials but the effect of temperature was not always significant. Cells with SSC, BSCF, and LSCF have shown a maximum power density about 20?mW?cm2 while the cell with LSM has given only 5?mW?cm2.