Electrical and electrochemical properties of the Sr(Fe,Co,Mo)O3-δ system as air electrode for reversible solid oxide cells

JOURNAL OF POWER SOURCES

卷:437

Article

Zapata-Ramirez, Victor¹  Mather, Glenn C.¹  Teresa Azcondo, Maria²  Amador, Ulises²  Perez-Coll, Domingo¹ 

[1] CSIC, Inst Ceram & Vidrio, Campus Cantoblanco, Madrid 28049, Spain

[2] Univ San Pablo CEU, CEU Univ, Fac Farm, Dept Quim & Bioquim, E-28668 Madrid, Spain

关键词: Air electrode;    Electrochemical performance;    Ionic transport number;    Ionic and electronic conductivity;    Impedance spectroscopy;    Reversible solid oxide cell;   

DOI  :  10.1016/j.jpowsour.2019.226895

来源: Elsevier

【 摘 要 】

The effects of Co and Mo doping on the properties of SrFeO3-delta perovskite as air electrode in reversible solid oxide cells have been analysed. The oxygen-ordered parent phase exhibits a high oxygen-vacancy content, which is partially reduced on doping, accompanied by stabilisation of cubic symmetry for SrFe0.9Mo0.1O3-delta and SrFe0.45Co0.45Mo0.1O3-delta phases. All compositions lose oxygen for temperatures >= 400-450 degrees C, with a concomitant decrease of electron-hole conductivity. Oxide-ionic conductivity determined by Faradic efficiency significantly improves for the Co-doped composition, reaching 0.026 S cm(-1) at 750 degrees C. The increase of ionic radii with reduction of Fe/Co + IV species results in greater thermal expansion for T > 450 degrees C. Polarization resistance without bias lowers considerably on Co doping, from similar to 0.55 Omega cm(2) for pure SrFeO3-delta, to similar to 0.2 Omega cm2 for SrFe0.45Co0.45Mo0.1O3-delta at 700 degrees C, but not on Mo doping (similar to 0.5 Omega cm(2)). However, under cathodic and anodic polarization, a comparable, excellent performance at 650 C of all compositions indicates their considerable promise as air electrodes for reversible solid oxide fuel cell-electrolyser systems, particularly for SrFe0.9Mo0.1O3-delta with more moderate thermal expansion.

【 授权许可】

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