Enhancing the performance and stability of solid oxide fuel cells by adopting samarium-doped ceria buffer layer

Abstract

In this work, the Sm0.2Ce0.8O1.9 (SDC) buffer layer was used to replace the Gd0.1Ce0.9O1.95 (GDC) buffer layer to improve the long-term stability and performance of the solid oxide fuel cells (SOFCs) in the intermediate temperature (550–750 °C). The buffer layer was prepared by screen printing method. The micromorphology of the SDC buffer layer and the cell structures was observed by scanning electron microscopy (SEM). The electrochemical impedance spectroscopy (EIS) results showed that the polarization resistance (RP) of the cell with SDC buffer layer was smaller than that of the cell with GDC buffer layer, reducing the RP values by 43.52% and 43.33%, respectively (SDC-cell: 0.12 Ω cm2 at 650 °C and 0.27 Ω cm2 at 600 °C). The maximum power density of the cell with SDC buffer layer is 560 mW cm−2 at 650 °C, which was 25% higher than that with GDC buffer layer. The long-term durability of the cell with SDC buffer layer was better than that of the cell with GDC buffer layer. These provide an excellent prospect for utilizing SDC buffer layer.