The　cobalt-free　layered　perovskite　oxides　Sm1-xLaxBaFe2O5+δ　(x　=　0-0.5)　(SLBFx,　for　short)　have　been　systematically　investigated　to　evaluate　the　feasibility　of　using　them　as　cathodes　for　intermediate-temperature　solid　oxide　fuel　cells　(IT-SOFCs).　SLBFx　powders　with　an　orthorhombic　structure　were　synthesized　by　the　EDTA-glycine　combustion　method　and　were　observed　to　be　compatible　with　LSGM　and　SDC　electrolytes　below　1250　°C.　The　electrical　conductivities　of　the　SLBFx　samples　significantly　increased　with　the　substitution　of　La　for　Sm,　with　the　highest　conductivity　of　37.8　S　cm-1　obtained　for　the　SLBF0.5　sample　at　600　°C.　Of　the　La-doped　SmBaFe2O5+δ　series　samples,　SLBF0.2　displayed　the　lowest　thermal　expansion　coefficient　(TEC)　and　the　minimum　electrode　polarization　resistance,　with　values　of　16.51　×　10-6　K-1　in　the　50-800　°C　range　and　0.24　Ω　cm2　at　750　°C,　respectively.　The　anode-supported　single　cell　with　SLBF0.2　as　the　cathode　was　able　to　generate　a　maximum　power　density　of　558　mW　cm-2　at　800　°C　in　humidified　H2.　All　things　considered,　SLBFx　materials　are　good　candidates　for　cobalt-free　cathodes　in　IT-SOFCs.　©　The　Royal　Society　of　Chemistry　2015.