Enhanced chromium tolerance of Gd0.1Ce0.9O 1.95 Impregnated La0.6Sr0.4Co 0.2Fe0.8O3-d electrode of solid oxide fuel cells

Abstract

The electrochemical activities and chromium tolerances are studied on pure La0.6Sr0.4Co0.2Fe0.8O 3-d (LSCF) and Gd0.1Ce0.9O1.95 (GDC) impregnated LSCF (GDC-LSCF) electrodes of solid oxide fuel cells. Using electrochemical impedance spectroscopy (EIS) technology, a significant reduction in the electrode polarization resistance (RE) for O2 reduction particularly at low temperatures is obtained after GDC impregnated. Form the analysis results of EIS, the low frequency resistances are markedly reduced due to a positive effect of GDC coating on oxygen dissociative adsorption process. Most importantly, the overpotential of GDC-LSCF electrode at 800 °C for 40 h in the presence of Fe-Cr metallic interconnect presents more stable than that of pure LSCF electrode, implying an enhanced Cr tolerance after GDC introduced. Moreover, SEM-EDS results indicate that Cr deposition is selective and occurs preferentially on LSCF surface rather than GDC, suggesting that GDC impregnation is a promising technique for the development of Cr-tolerance electrode in SOFCs. © The Electrochemical Society.