Composite La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) and Ce0.8Sm0.2O1.9 (SDC) cathodes for solid oxide fuel cells (SOFCs) were fabricated by axial-injection plasma spraying. Fine mixing of the ceramic phases was achieved by using a nano-structured feedstock that contained both phases agglomerated together in larger particles. Preliminary investigations explored the effects of varying the process parameters, and cathodes were characterized by XRD and SEM. Metal-supported symmetrical cells were made with several promising sets of process parameters, and the polarization resistance was measured from 550 degrees C to 750 degrees C. The cathode with the highest electrochemical performance was incorporated into a fuel cell with a yttria-stabilized zirconia (YSZ) electrolyte and a nickel-YSZ anode. A fuel cell with a coarsely-mixed composite cathode was also fabricated, and the effect of the cathode microstructure on cell impedance was studied using the analysis of differential impedance spectra. (C) 2013 Elsevier B.V. All rights reserved.