SmBaCo1.7Ni0.3O5+δ-xSm0.2Ce0.8O1.9　(SBCN-xSDC,　x　=　0-50　wt.%)　composite　cathodes　were　prepared　and　characterized　for　potential　use　in　intermediate-temperature　solid　oxide　fuel　cells　(IT-SOFCs)　based　on　an　SDC　electrolyte.　The　electrical　conductivity　and　the　thermal　expansion　coefficient　(TEC)　decreased　with　an　increase　in　the　SDC　content　of　SBCN-xSDC　composite　cathodes.　TEC　values　decreased　from　15.59　×　10-6　K-1　for　SBCN　to　13.17　×　10-6　K-1　for　SBCN-50SDC.　Furthermore,　the　addition　of　SDC　to　the　SBCN　cathode　improved　its　electrochemical　performance.　Among　others,　the　SBCN-20SDC　showed　the　lowest　polarization　resistance　of　0.0272　Ω　cm2　at　800　°C;　an　anode-supported　single-cell　configuration　of　Ni-SDC/SDC/SBCN-20SDC　obtained　a　maximum　power　density　of　628　mW　cm-2　at　800　°C.　Even　when　the　content　of　SDC　was　raised　up　to　50　wt.%,　the　electrochemical　performance　of　SBCN-50SDC　still　exceeded　that　of　pure　SBCN.　These　results　indicated　that　the　SBCN-xSDC　composite　cathode　is　a　promising　material　for　IT-SOFCs.　©　2015　Hydrogen　Energy　Publications,　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.