Anode-supported solid oxide fuel cells (SOFCs) comprising NiO-samarium-doped ceria (SDC) (Sm0.2Ce0.8O1.9) composite anode, thin tri-layer electrolyte, and La0.6Sr0.4Co0.8Fe0.2O3 (LSCF)-La0.9Sr0.1Ga0.8Mg0.2O3-delta (LSGM) composite cathode were fabricated. The thin tri-layer consisting of an 11-mu m thick LSGM electrolyte layer and a 12-mu m thick La0.4Ce0.6O1.8 (LDC) layer on each side of the LSGM was prepared by centrifugal casting and co-firing technique. The performance of the cells operated with humidified H-2 as fuel and ambient air as oxidant showed a maximum power density of 1.23 W cm(-2) at 800 degrees C. A stability test of about 100 h was carried out and some deterioration of output power was observed, while the open circuit voltage (OCV) kept unchanged. Impedance measurements showed that both the electrolyte ohmic resistance and the electrode polarization increased with time and the latter dominated the degradation. (c) 2008 Elsevier Ltd. All rights reserved.