Preparation, Characterization, and Kinetic Testing of Infiltrated LSF-YSZ Electrodes for Symmetric Solid Oxide Cells

In this work, symmetric electrolyte-supported YSZ (yttria-stabilized zirconia) cells infiltrated with LSF (La0.8Sr0.2FeO3O3-δ) were prepared, characterized, and tested in the oxygen reduction reaction (ORR). The fabrication procedure of the cells was optimized with respect to the formulation of the electrolyte and electrode slips. Aqueous solutions of nitrates were used for the LSF-YSZ electrodes, which were morphologically characterized prior and after infiltration. The effects of calcination temperature (between 700 and 1050 °C) and precursors load (between 10% and 50% w/w) on the ORR activity were investigated. Electrochemical impedance spectroscopy (EIS) experiments were performed between 650 and 750 °C, with air and varying the O2 partial pressure from 5% to 100%. The minimum polarization resistance was measured after calcination at 750 °C, while LSF loads between 20% and 40% maximized the performance. Equivalent circuit analysis of the EIS results suggested that the surface reactivity at the LSF/gas interface is rate-determining.