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

Abstract

Abstract Four cathode materials for single chamber solid oxide fuel cell (SC‐SOFC) [La 0.8 Sr 0.2 MnO 3–δ (LSM), Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3–δ (BSCF), Sm 0.5 Sr 0.5 CoO 3–δ (SSC), and La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3–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 Ce 0.9 Gd 0.1 O 2–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 .