Design, Synthesis, Structure and Properties of Ba-Doped Derivatives of SrCo0.95Ru0.05O3-δ Perovskite as Cathode Materials for SOFCs.

We have designed and prepared a novel cathode material for solid oxide fuel cell (SOFC) based on SrCo0.95Ru0.05O3-δ perovskite. We have partially replaced Sr by Ba in Sr0.9Ba0.1Co0.95Ru0.05O3-δ (SBCRO) in order to expand the unit-cell size, thereby improving the ionic diffusion of O2- through the crystal lattice. The characterization of this new oxide has been studied at room temperature by X-ray diffraction (XRD) and neutron powder diffraction (NPD) experiments. At room temperature, SBCRO perovskite crystallizes in the P4/mmm tetragonal space group, as observed from NDP data. The maximum conductivity value of 18.6 S cm-1 is observed at 850 °C. Polarization resistance measurements on LSGM electrolyte demonstrate an improvement in conductivity with respect to the parent Sr-only perovskite cathode. A good chemical compatibility and an adequate thermal expansion coefficient make this oxide auspicious for using it as a cathode in SOFC.