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

International audienceFour cathode materials for single chamber solid oxide fuel cell (SC-SOFC) [La0.8Sr0.2MnO3-δ (LSM), Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF), Sm0.5Sr0.5CoO3-δ (SSC), and La0.6Sr0.4Co0.2Fe0.8O3-δ (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 Ce0.9Gd0.1O2-δ (CGO) electrolyte and a Ni-CGO anode, were tested in several methane/air mixtures with each cathode materials between 625 and 725 °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 cm-2 while the cell with LSM has given only 5 mW cm-2