Polarization Resistances of (Ln(1-x)Sr(x))CoO3 (Ln=Pr, Nd, Sm, and Gd x=0, 0.3, 0.5, 0.7, and 1) as Cathode Materials for Intermediate Temperature-operating Solid Oxide Fuel Cells

Abstract

This study focuses on cathode performances of (Ln(1-x)Sr(x))CoO3-delta (Ln=Pr, Nd, Sm, and Gd, x=0, 0.3, 0.5, 0.7, and 1) for intermediate temperature-operating solid oxide fuel cells (IT-SOFCs, 600-800 degrees C). (Ln(1-x)Sr(x))CoO3-delta powders as cathode materials for IT-SOFC, which can be operated between 600 degrees C and 800 degrees C were synthesized by the glycine-nitrate-process (GNP) method. The impedance spectroscopy method was used to investigate area specific resistance (ASR) and electrochemical properties of (Ln(1-x)Sr(x))CoO3-delta (Ln=Pr, Nd, Sm, and Gd, x=0, 0.3, 0.5, 0.7, and 1). Pr0.5Sr0.5CoO3-delta and Pr0.3Sr0.7CoO3-delta showed to 0.15 cm(2) of ASR at 700 degrees C and Nd0.5Sr0.5CoO3-delta to 0.14 cm(2) at 700 degrees C. Sm0.5Sr0.5CoO3-delta showed the lowest ASR values of 0.10 cm(2) on 10% Gd-doped cerium oxide at 700 degrees C.