New Rhenium-Doped SrCo1-xRexO3-delta Perovskites Performing as Cathodes in Solid Oxide Fuel Cells

作者：Troncoso Loreto^*; Celeste Gardey Maraa; Teresa Fernandez Diaz Maria; Antonio Alonso Jose

来源：Materials, 2016, 9(9): 717.

DOI：10.3390/ma9090717

• IT-SOFC
• hydrogen
• cathode
• neutron diffraction
• SrCoO3

In the aim to stabilize novel three-dimensional perovskite oxides based upon SrCoO3 d, we have designed and prepared SrCo1-xRexO3-delta phases (x = 0.05 and 0.10), successfully avoiding the competitive hexagonal 2H polytypes. Their performance as cathode materials in intermediate-temperature solid oxide fuel cells (IT-SOFC) has been investigated. The characterization of these oxides included X-ray (XRD) and in situ temperature-dependent neutron powder diffraction (NPD) experiments for x = 0.10. At room temperature, SrCo1-xRexO3-delta perovskites are defined in the P4/mmm space group, which corresponds to a subtle tetragonal perovskite superstructure with unit-cell parameters a = b approximate to a(0), c = 2a(0) (a(0) = 3.861 and 3.868 angstrom, for x = 0.05 and 0.10, respectively). The crystal structure evolves above 380 degrees C to a simple cubic perovskite unit cell, as observed from in-situ NPD data. The electrical conductivity gave maximum values of 43.5 S . cm(-1) and 51.6 S . cm(-1) for x = 0.05 and x = 0.10, respectively, at 850 degrees C. The area specific resistance (ASR) polarization resistance determined in symmetrical cells is as low as 0.087 W . cm(2) and 0.065 W . cm(2) for x = 0.05 and x = 0.10, respectively, at 850 degrees C. In single test cells these materials generated a maximum power of around 0.6 W/ cm2 at 850 degrees C with pure H-2 as a fuel, in an electrolyte-supported configuration with La0.8Sr0.2Ga0.83Mg0.17O3-delta (LSGM) as the electrolyte. Therefore, we propose the SrCo1-xRexO3-delta (x = 0.10 and 0.05) perovskite oxides as promising candidates for cathodes in IT-SOFC.

• 出版日期2016-9