A cobalt-free composite Sm0.5Sr0.5Fe0.8Cu0.2O3-delta-Ce0.8Sm0.2O2-delta (SSFCu-SDC) is investigated as a cathode for proton-conducting solid oxide fuel cells (H-SOFCs) in intermediate temperature range, with BaZr0.1Ce0.7Y0.1Yb0.1O3-delta (BZCYYb) as the electrolyte. The XRD results show that SSFCu is chemically compatible with SDC at temperatures up to 1100 degrees C. The quad-layer single cells of NiO-BZCYYb/NiO-BZCYYb/BZCYYb/SSFCu-SDC are operated from 500 to 700 degrees C with humidified hydrogen (similar to 3% H2O) as fuel and the static air as oxidant. It shows an excellent power density of 505 mW cm(-2) at 700 degrees C. Moreover, a low electrode polarization resistance of 0.138 Omega cm(2) is achieved at 700 degrees C. Preliminary results demonstrate that the cobalt-free SSFCu-SDC composite is a promising cathode material for H-SOFCs. (C) 2010 Elsevier B.V. All rights reserved.