Cathode performance and deposited Cr under Cr poisoning condition in the (La0.6Sr0.4)(Co0.2Fe0.8)O3 cathode

The Cr poisoning behavior of LSCF6428 cathode was investigated under Cr containing vapor conditions at 1073 K using LSCF6428/GDC/Pt cells. Under a cathodic polarization of - 200 mV, cathode current decreased by supplying of Cr containing vapor. From the AC impedance, a significant increase of the polarization resistance (low frequency contribution) was observed during cell tests. Post-analysis of operated samples showed that a thick SrCrO4 layer was formed on the surface of LSCF cathode and a small amount of SrCrO4 was found inside. From the long-term operated sample (380 h), pore-like dark spots were confirmed in LSCF grains. Correlation between LSCF cathode performance and deposited Cr was deduced from change of polarization resistance and the amount of deposited Cr (Cr/La ratio) in LSCF cathode.