High-performance Gd0.2Ce0.8O2-impregnated LaNi0.6Fe0.4O3-δ cathodes for intermediate temperature solid oxide fuel cell

High-performance LaNi0.6Fe0.4O3-delta (LNF) cathode for intermediate temperature solid oxide fuel cell is fabricated by the ion impregnation of oxygen ion conducting Gd-doped ceria (CDC, Gd0.2Ce0.8O2). The microstructure of the GDC-impregnated LNF cathode is characterized by the dispersion of nano-sized GDC particles in the LNF porous framework. The particle size of the impregnated GDC phase is in the range of 40-50 nm. Uniform distribution of the nano-sized ionic conducting GDC phase significantly enhances the cathode activities for the O-2 reduction reaction. In the case of the 21.3 wt.% GDC-impregnated LNF cathode, the specific polarization resistance (R-p) is 0.13 Omega cm(2) at 750 degrees C, a reduction by 81.43% compared with that of the pure LNF cathode at the same temperature. The results indicate that GDC impregnation has significant electrocatalytic effect on the O-2 reduction reactions on the LNF cathodes. The improved performance of GDC-impregnated LNF cathode is attributed to the extended triple-phase boundary (TPB) and enhanced oxide ion conductivity. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.