The cathode is a key component in low temperature solid oxide fuel cells. In this study, composite cathode, 75 wt.% SM0.5Sr0.5CoO3 (SSC) + 25 wt.% Sm0.2Ce0.8O1.9 (SDC), was applied on the cermet supported thin SDC electrolyte cell which was fabricated by tape casting, screen-printing, and co-firing. Single cells with the composite cathodes sintered at different temperatures were tested from 400 to 650 degrees C. The best cell performance, 0.75 W cm(-2) peak power operating at 600 degrees C, was obtained from the 1050 degrees C sintered cathode. The measured thin SDC electrolyte resistance R-s was 0.128 Omega cm(2) and total electrode polarization R-p(a + c) was only 0.102 Omega cm2 at 600 degrees C. (c) 2006 Elsevier B.V. All rights reserved.