In this study we consider several heretofore unexplored composite cathode materials systems for solid oxide fuel cells (SOFCs), whose compositions and microstructures have been optimized for high electrocatalytic activity for oxygen reduction reaction and for chemical stability.  The design approach takes into account the need for combining facile oxygen surface reactions with bulk transport.

The new composite cathodes in this study consists of carefully tailored composition of perovskite type MIECs and fluorite type ionic conductors.

In this study, all components of the button cells with composite MIEC cathode functional layer (CFL) were prepared via tape casting. Electrochemical performance of these button cells were analyzed through polarization modelling and impedance spectroscopy at temperatures between 700 and 900°C and at cathode side oxygen partial pressures between 1 and 5x10^-2 atm. The effect of cathode microstructure on the cell performance is also discussed.