Electrochemical performance and stability of lanthanum strontium cobalt ferrite oxygen electrode with gadolinia doped ceria barrier layer for reversible solid oxide fuel cell

A La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) oxygen electrode and a Gd0.1Ce0.9O2−δ (GDC) barrier layer are prepared for a reversible solid oxide fuel cell (RSOFC). Scanning electron microscopy (SEM) analysis shows that the GDC barrier layer has a honeycomb-like structure and maintains good adhesion with yttria-stabilized zirconia (YSZ) electrolyte and LSCF oxygen electrode. Polarization curves and electrochemical impedance spectra for both fuel cell and steam electrolysis modes are investigated. Repeated fuel cell/steam electrolysis cycles operated at 300 mA cm−2 and 800 °C shows the cell has higher degradation under steam electrolysis mode than under fuel cell mode. Cell degradation in electrolysis mode is attributed to delamination of the GDC barrier layer from the YSZ electrolyte, which has been observed during post-test SEM analysis.