Electrochemical performance and Cr tolerance in a La1-xBaxCo0.9Fe0.1O3-δ (x = 0.3, 0.4 and 0.5) cathode for solid oxide fuel cells

Abstract

The electrochemical performance and Cr poisoning behavior of La1-xBaxCo0.9Fe0.1O3-δ (LBCF, x = 0.3, 0.4, 0.5) and La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) cathodes were investigated for solid oxide fuel cells (SOFCs). The polarization resistance of the LBCF/GDC/LBCF symmetrical cell was found to decrease with increasing Ba content (x value). This phenomenon might be associated with the high oxygen vacancy concentration in the LBCF sample, with x = 0.5. In addition, there was no chromium poisoning in the LBCF cathode. On the other hand, the polarization resistance of the LSCF cathode was found to significantly increase after exposure to gaseous chromium species; it appears that this result stemmed from the formation of SrCrO4 phase. Therefore, it can be expected that LBCF can be a durable potential cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFC).