Chromium poisoning and degradation at LaNi0.6Fe0.4O3 cathode with LaNi0.6Fe0.4O3–Gd0.2Ce0.8O2 functional layer for SOFC under open circuit condition

We fabricate symmetrical cells adopting LaNi 0.6 Fe 0.4 O 3–δ (LNF) cathode with LNF–Gd 0.2 Ce 0.8 O 2 (GDC) functional layer on scandia-stabilized zirconia electrolyte by screen printing. Degradation of cathode performances by Cr poisoning is studied. Specific polarization resistance ( R p ) increases with time to power of 1/4 and 1/3 in LNF cathode with and without functional layer under exposure of Cr vapors at 750 °C for 900 and 500 h, respectively. Electrochemical impedance spectra illustrate LNF exhibits greater R p than that of LNF with functional layer under exposure of Cr vapors due to strong Cr deposition at LNF/ scandia stabilized zirconia (ScSZ) interface. No significant degradation in performance has been observed after 900 h of operating under the same condition due to very little Cr deposition at LNF-GDC/ScSZ interface, suggesting little poisoning effect for O 2 reduction on LNF cathode with functional layer. These demonstrate LNF cathode with functional layer has high resistance towards Cr deposition and high tolerance towards Cr poisoning.