Characterization of Sr 1– x Dy x CoO 3–δ ( x = 0.1, 0.2, 0.3) Cathode Materials for IT‐SOFCs

The cobaltate perovskites Sr 1– x Dy x CoO 3–δ (SDCO, x  = 0.1, 0.2, 0.3) materials were synthesized and evaluated as cathode for La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3–δ solid electrolyte supported intermediate‐temperature‐solid oxide fuel cells (IT‐SOFCs). The crystal structure of Sr 0.9 Dy 0.1 CoO 3–δ was defined in the cubic Pm –3 m space group (No. 221), Sr 0.8 Dy 0.2 CoO 3–δ and Sr 0.7 Dy 0.3 CoO 3–δ had a tetragonal I 4/ mmm structure. The electrical conductivities were all higher than 100 S cm –1 in the temperature of 170–800 °C. The polarization resistance ( R p ) and its activation energy ( E a ) increased with increasing x . SEM analysis confirmed the porous microstructure of the SDCO cathodes and good LSGM|LDC|SDCO adherence. Sr 0.9 Dy 0.1 CoO 3–δ exhibited the best cathode characteristics with a maximum test‐cell power density of 841 mW cm –2 , being a high potential candidate of cathode material for IT‐SOFCs.