Interface Resistance of an SOFC Cathode with a Pr 1-X Tb x O 2-D Active Layer

Abstract

We investigated the use of Pr1-XTbxO2-d (x=0.0-1.0) for use as the active layer material in an SOFC cathode. Pr1-XTbxO2-d (x=0.0-1.0) was successfully synthesized in a single-phase fluorite structure consisting of a solid solution of Pr6O11 and Tb4O7. When x was between 0.3 and 0.6, the phase transition between room temperature and 800oC was eliminated. Coin cells with GDC electrolyte, a Pr1-XTbxO2-d (x=0.0-1.0) active layer and a LaNi0.6Fe0.4O3 (LNF) current collecting layer were fabricated to clarify the effect of this active layer. The interface resistance of these cathodes was measured with an AC impedance method at 800oC. The cathodes with a Pr1-XTbxO2-d (all compositions) active layer performed better than that of a reference cathode, which has no active layer (simply an LNF layer).