Interface Resistance of an SOFC Cathode with a Pr1−xTbxO2−d Active Layer

Abstract

We investigated the use of Pr1−xTbxO2−d (x = 0.0–1.0) 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 800 °C 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 800 °C. The cathodes with a Pr1−xTbxO2−d (all compositions) active layer performed better than a reference cathode with no active layer (simply an LNF layer).