LaCoO3-δ coated Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode for intermediate temperature solid oxide fuel cells

Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ (BSCF) is a promising cathode for intermediate temperature solid oxide fuel cells. However, BSCF cathode performance stability has been a challenge and its electrochemical performance deteriorates severely in the presence of Cr₂O₃-forming metallic interconnect. We demonstrate that LaCoO_3-δ (LC) coating on BSCF cathode can not only enhance BSCF electrochemical performance, but also effectively improve the BSCF performance stability. In this study, LC-coated BSCF-Gd_0.1Ce_0.9O_1.9 (LC@BSCF-GDC) cathode is prepared through a solution impregnation method and systematically characterized. EIS, XRD, Raman, SEM and EDS tests with and without SUS430 interconnect are conducted to characterize the Cr-tolerance. The results show that BSCF-GDC cathode is susceptible to Cr poisoning while LC@BSCF-GDC cathode has significantly enhanced tolerance to Cr poisoning. Single cells with LC@BSCF-GDC cathode achieve higher peak power density and smaller polarization resistance values than single cells with BSCF-GDC cathode. Furthermore, significant improvement of performance stability under a constant current load has been achieved for single cells with LC@BSCF-GDC cathode. This work provides a new solution for solving BSCF cathode performance stability.