Enhanced oxygen diffusion in low barium-containing La0.2175Pr0.2175Ba0.145Sr0.4Fe0.8Co0.2O3−δ intermediate temperature solid oxide fuel cell cathodes

► (La-Pr-Ba)0.58Sr0.4Fe0.8Co0.2O3−δ cathodes possess high oxygen diffusion properties. ► Isotopic exchange depth profiling experiments corroborated EIS results. ► Combinatorial mixture design gives rise to high performing cathodes