Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2011-08-01

Journal: JOURNAL OF POWER SOURCES

Included Journals: EI、SCIE

Volume: 196

Issue: 15

Page Number: 6022-6028

ISSN: 0378-7753

Key Words: Solid oxide fuel cell; Degradation mechanism; Bimetallic anode; Ni; Re-oxidation; Methane

Abstract: Degradation mechanism of Ni0.5Cu0.5-Gd0.2Ce0.8O1.9 (CGO) bimetallic anode in low concentrations of dry methane is studied with a (La0.25Sr0.25)(0.95)MnO3-delta-CGO cathode supported SOFC. Leakage tests suggested that as-prepared cells are well-sealed by glass ring at elevated temperatures. OCV of as-prepared cell in each concentration of CH4 is over 1.2 V. indicating that the ScSZ electrolyte film prepared by a dual drying pressing method is dense enough. It is found that rapid degradation phenomenon easily occurred at relatively high current density in 7.4 and 14.8% of dry methane in the performance test. XRD and EIS analyses indicated that the degradation of the Ni0.5Cu0.5-CGO anode at high current density could be mainly attributed to the re-oxidation of Ni. GC results showed that the re-oxidation of Ni always occurred at a relatively high p(H2O), which always appeared at a relatively high current density. The degraded cell is successfully recovered by burning the anode with O-2 and re-reducing with H-2. (C) 2011 Elsevier B.V. All rights reserved.