The long-term operation of an anode-supported solid oxide fuel cell was examined to study the degradation factor. The cell was constructed using LaNi0.6Fe0.4O3 (LNF), alumina-doped scandia stabilized zirconia (SASZ). and NiO-SASZ as the cathode, electrolyte, and anode respectively. The cell had Pt current collectors and was operated for 6500 h. The test was carried out at 1073 K with a constant load of 0.4 A cm(-2) and included thermal cycling. The cell voltage degradation rate was below 0.86%/1000 h when the cell was operated for Lip to 5200 h. Changes in the resistance of the cells during the experiments were analyzed by impedance spectroscopy. The cathode polarization resistance and ohmic resistance increased with time. The elements (Si and B) contained in the water condensed from the cathode exhaust gas were identified using inductively coupled plasma (ICP). (C) 2009 Elsevier B.V. All rights reserved.