A stability study of impregnated LSCF-GDC composite cathodes of solid oxide fuel cells

作者：Liu Yihui; Wang Fangzhong; Chi Bo^*; Pu Jian; Jian Li; Jiang San Ping

来源：Journal of Alloys and Compounds, 2013, 578: 37-43.

DOI：10.1016/j.jallcom.2013.05.021

• Solid oxide fuel cells
• Degradation
• Nano-structured LSCF-GDC cathodes
• Impregnation
• Microstructure coarsening

The performance degradation of composite cathodes of La0.6Sr0.4Co0.2Fe0.8O3-delta and Gd-doped ceria (LSCF-GDC), prepared by impregnating the porous GDC scaffold with a nitrate solution containing La, Sr, Co and Fe in desired composition, is investigated at 750 degrees C and open circuit in air for 500 h. The performance of the impregnated LSCF-GDC composite cathodes deteriorates after testing at 750 degrees C for 500 h; the electrode polarization resistance (R-p) increases from 0.38 to 0.83 Omega cm(2), and the electrode ohmic resistance (R-o) increases from 1.79 to 2.14 Omega cm(2). The grain growth and coarsening of impregnated LSCF nanoparticles are responsible for the performance degradation of the cathodes. XPS analysis shows the enrichment of cobalt on the surface of the infiltrated LSCF-GDC cathodes and such surface segregation could also contribute to the degradation of the electrocatalytic activity of the cathodes. Introducing MgO and LaNi0.6Fe0.4O3 phases can effectively suppress the coarsening of LSCF nanoparticles and enhance the stability of the cathodes. However, the enhancing effect is related to the conductivity and electrocatalytic activity of the introduced phases.

• 出版日期2013-11-25
• 单位华中科技大学