Cathode-supported solid oxide fuel cell (SOFC) consisting of a Ni-Gd(0.2)Ce(0.8)O(1.9) (Ni-CGO) anode with a Sc(2)O(3)-doped ZrO(2) (ScSZ) electrolyte on a (La(0.75)Sr(0.25))(0.95)MnO(3-delta) (LSM)+CGO cathode substrate was fabricated via a dual drying pressing followed by co-firing method. Open circuit voltage (OCV) of as-prepared cell in pure H(2) reached 1.238 at 800 degrees C, indicating that the ScSZ electrolyte film prepared by the present method was dense enough and the cell was in a well-sealed state. Performance degradation phenomenon of Ni-CGO anode in low concentration of H(2) was investigated by gradual loading of the system current. Re-oxidation of Ni, which was not caused by O(2) in the case of mechanical damage, was supposed to occur at a high current density. According to the EIS and SEM analysis results, it is inferred that the Ni could be oxidized by the oxygen ion at a high current density in low concentration of H2 as well as by the produced H(2)O with a high p(H(2)O)/p(H(2)) ratio. In this case, the performance of the degraded cell was unable to be directly regenerated by hydrogen reduction unless the anode was firstly burnt in O(2) before reduced in H(2). It is possible that H(2)O molecules covered on the NiO due to oxidation of Ni by H(2)O, which hindered NiO to be reduced by H(2), could be moved out by O(2) burning. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.