Evaluation of performances of solid oxide fuel cells with symmetrical electrode material

• PxSCFN oxide is developed as symmetrical electrode material for SOFC.
• Pr element content in PxSCFN has great effect on SOFC performance.
• Nano-sized Co-enriched particles are obviously formed in anode side.
• Pr3+/Pr4+, Co2+/Co3+ and Fe2+/Fe3+/Fe4+ coexist in PxSCFN.

PrxSr0.6Co0.2Fe0.7Nb0.1O3−σ (PxSCFN, x = 0.38, 0.40, 0.42 and 0.44) oxide has been developed as symmetrical electrode material for solid oxide fuel cell (SOFC) in our group. In this study, the effect of Pr element contents on the cell performance of the PxSCFN symmetrical electrode SOFC is investigated in details. Electrochemical impedance spectra (EIS) technique, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) are used to characterize the electrodes after the performance test. It is found that the nano-sized Co-enriched particles are obviously formed in anode side, which could contribute to the high catalytic activity of the PxSCFN symmetrical electrode materials. An optimum x value, i.e., 0.42, is found for the PxSCFN symmetrical electrode materials. As-prepared single cell shows an average slow degradation rate of 0.5 mV h−1 during 100 h stability test, indicating that the symmetrical SOFC with PSCFN as electrode has the acceptable stabilization. X-ray photoelectron spectroscopy (XPS) analysis indicated that the content of Sr2+ species on the surface decreases to some extent in the case of A-site Pr element slight excess, which could result in the promoting of the catalytic properties of PSCFN material.

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