ReBaCo2-xMnxO5+δ (Re: rare earth element) layered perovskites for application as cathodes in Solid Oxide Fuel Cells

Decrease of the operation temperature is considered as one of the most important targets in development of Solid Oxide Fuel Cells (SOFC), as it leads to considerable extension of their long-term operation and makes construction and utilization of the SOFC generators cost-effective. Relatively high value of the activation energy of the oxygen reduction reaction (ORR) occurring at the cathode, and consequently, large cathodic polarization resistance at lower temperatures is a major obstacle hindering usage of SOFCs at decreased temperatures. In this work possibility of application of manganese-doped cobalt-based cation-ordered perovskites as candidate cathode materials in the intermediate temperature ( IT, ca. 600-800 degrees C) range is discussed. The considered oxide materials, depending on chemical composition, i.e. choice of Re element and Mn-doping level exhibit high values of mixed ionic-electronic conductivity, as well as good catalytic activity toward the oxygen reduction and moderate thermal expansion. Cathode layers manufactured on a basis of selected ReBaCo2-xMnxO5+delta oxides show low polarisation resistance.