Electrochemical properties of an ordered perovskite LaBaCo2O5 (+) (delta)-Ce0.9Gd0.1O2 (-) (delta) composite cathode with strontium doping for intermediate-temperature solid oxide fuel cells

Abstract

The effects of Sr substitution for Ba on the structural properties, oxygen content, electrical conductivity, and electrochemical performance of a cation-ordered perovskite LaBaCo2O5+δ (LBCO) oxide have been investigated in relation to the application of LBCO as a cathode material for IT-SOFC applications. The electrical conductivity of LaBa0.5Sr0.5Co2O5+δ (LBSCO) in air decreases with increasing temperature. At the temperature range of 100-850°C, the electrical conductivity of LBSCO is much higher than that of Sr-free LBCO. The minimum area specific resistance value is achieved at LBSCO composite with 40wt.% Ce0.9Gd0.1O2-δ (GDC). The best performance of LBSCO-40GDC based on a GDC electrolyte reaches 1.254Wcm-2 at 600°C. These data allow us to propose that the LBSCO-40GDC is a good candidate for IT-SOFC applications.