To stabilize solid oxide fuel cell cathodes prepared by infiltration of La0.8Sr0.2CoO3 (LSCo) into porous yttria-stabilized zirconia (YSZ), a coating of Sm-doped ceria (SDC) was first deposited onto the YSZ scaffold. The dense SDC coating was prepared by infiltration with aqueous solutions of Sm(NO3)(3) and Ce(NO3)(3), followed by calcination to 1473 K. The SDC coating prevented solid-state reactions between LSCo and YSZ at 1373 K. LSCo-SDC/YSZ electrodes exhibited low cathode impedances, similar to 20 m Omega cm(2), at 973 K, with acceptable degradation after heating to 1373 K. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3432253] All rights reserved.