Achieving high performance of Sr-doped ordered perovskite LaBaCo2O5+δ cathode for intermediate-temperature solid oxide fuel cells

Abstract

The effect of Sr substitution for Ba on the structural property, oxygen content, electrical conductivity and electrochemical performance of cation-ordered perovskite LaBaCo2O5+δ (LBCO) oxide have been investigated as a cathode material for IT-SOFC applications. The electrical conductivity of LaBa0.5Sr0.5Co2O5+δ (LBSCO) in air decreases with increasing temperature, showing a metallic behavior. At the given temperature, the electrical conductivity of LBSCO is much higher than that of Sr-free LBCO. The area specific resistance of LBSCO-GDC cathode on GDC electrolyte are 0.854, 0.307, 0.119, and 0.051 W cm2 at 500, 550, 600, and 650o C, respectively. The maximum power densities of the single cell with LBSCO-GDC cathode based on a GDC electrolyte are 0.411, 0.783, 1.254, and 1.618 W cm−2 at 500, 550, 600, and 650o C, respectively. These results indicate that the LBSCO-GDC cathode is a promising candidate for IT SOFC applications.