Layered LnBaCo[sub 2−x]Cu[sub x]O[sub 5+δ] (0≤x≤1.0) Perovskite Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells

The effects of Cu substitution on the crystal chemistry, thermal and electrical properties, and catalytic activity for the oxygen reduction reaction of the layered ( and Gd, and ) perovskite have been investigated. The compositions exhibit thermal expansion coefficients (TEC) of for and for in the range of . The ( for and for ) cathodes exhibit low polarization resistance and fuel cell performance comparable to that of the well-known perovskite cathodes, but with an important advantage of lower TEC. The better performance of these Cu-substituted samples is partly due to the improved chemical stability with the electrolyte at high temperatures and a better matching of the TEC value with those of the standard electrolytes. With an electrolyte-supported single cell configuration , and exhibit higher maximum power densities of, respectively, 772 and at compared to that of the Cu-free sample (658 and ).