La-Doped BaCoO[sub 3] as a Cathode for Intermediate Temperature Solid Oxide Fuel Cells Using a LaGaO[sub 3] Base Electrolyte

Cathodic behavior of doped with La was investigated in this study for an intermediate temperature solid oxide fuel cell (ITFC). Electrical conductivity of increased monotonically with an increasing amount of La doped for the Ba site at 1073 K Cathodic overpotential at 1073 K decreased with increasing La content and attained a minimum at in Since the cathodic overpotential of kept a small value at decreased temperature, is the optimum composition for the cathode of an ITFC among -based oxides. When was used for the electrolyte, the power density of the cell using for the cathode at 1073 K attained a value of 550 mW/cm 2 , which is slightly higher than that using for the cathode. In addition, a low cathodic overpotential of was also maintained in air. exchange reaction was performed to estimate the surface activity for oxygen dissociation. It was found that exhibits high activity for the oxygen exchange reaction. Therefore, superior cathode property was assigned to the high surface activity of © 2002 The Electrochemical Society. All rights reserved.