Application of (Sm0.5 Sr0.5)CoO3 to (Zr, Sc)O2 Electrolyte SOFCs for Reduced Temperature Operation

Abstract

Application of (Sm 0.5 Sr 0.5 )CoO 3 (SSC) as a cathode material on Zr 0.89 Sc 0.1 Ce 0.01 O 1.95 electrolyte for reduced temperature operation SOFCs was investigated in detail. As a protective layer for the electrolyte, doped ceria thin films were fabricated on the electrolyte by a cost effective wet ceramic process using nanometer Ce 0.8 Sm 0.2 O 1.9 and submicrometer Ce 0.9 Gd 0.1 O 1.95 powders. The impact of doped ceria interlayer on the performance of (Sm 0.5 Sr 0.5 )CoO 3 cathode was investigated by XRD and AC impedance measurements. It was found that controlling the microstructure of the interlayer is important for (Sm 0.5 Sr 0.5 )CoO 3 cathodic performance. The SSC cathode deposited on SSZ electrolyte coated by (Ce 0.8 Sm 0.2 )O 1.9 or (Ce 0.9 Gd 0.1 )O 1.95 interlayer can reach an interface conductivity of 4.4 S/cm 2 or 7.2 S/cm 2 at 700°C, respectively.