LaSr₃Fe_3-yCo_yO_10-δ (0 ≤ y ≤ 1.5) Intergrowth Oxide Cathodes for Intermediate Temperature Solid Oxide Fuel Cells

LaSr 3 Fe 3 - y Co y O 10 - δ (0 ≤ y ≤ 1.5) oxides with a perovskite-related intergrowth structure have been investigated as cathode materials for oxygen reduction reaction in intermediate temperature solid oxide fuel cells (SOFC). The electrical conductivity, oxygen vacancy concentration, and thermal expansion coefficient (TEC) increase with increasing Co content y . The electrocatalytic activity and power density measured with the LaSr 3 Fe 3 - y Co y O 10 - δ /La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 2.8 (LSGM)/Ni−Ce 0.9 Gd 0.1 O 1.95 (GDC) single cells with a porous Ce 0.9 Gd 0.1 O 1.95 (GDC) interlayer between the cathode and the electrolyte to avoid undesired interfacial reactions increase with increasing Co content because of an increase in the electronic and oxide ion conductivities of the cathode. The intergrowth LaSr 3 Fe 3 - y Co y O 10 - δ cathodes offer electrochemical performances comparable to that of the well-known pervskite La 0.6 Sr 0.4 CoO 3 - δ cathode but with an important advantage of significantly lower TEC.