Design, Synthesis, Structure and Properties of Ba-Doped Derivatives of SrCo_0.95Ru_0.05O_3−δ Perovskite as Cathode Materials for SOFCs

• Main Authors: Sabina Sydyknazar, Vanessa Cascos, Loreto Troncoso, Ana Laura Larralde, María Teresa Fernández-Díaz, José Antonio Alonso
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Materials
• Subjects: IT-SOFC; cathode; perovskite; neutron diffraction; SrCoO₃
• Online Access: https://www.mdpi.com/1996-1944/12/12/1957
• ISSN: 1996-1944

We have designed and prepared a novel cathode material for solid oxide fuel cell (SOFC) based on SrCo_0.95Ru_0.05O_{3−δ} perovskite. We have partially replaced Sr by Ba in Sr_0.9Ba_0.1Co_0.95Ru_0.05O_{3−δ} (SBCRO) in order to expand the unit-cell size, thereby improving the ionic diffusion of O^2− 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.