Peng Qiu,Ao Wang,Haoyu Zheng,Lichao Jia,Bo Chi,Jian Pu,Jian Li
LaCoO 3-δ (LC)-coated Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ (BSCF) cathode is fabricated by the solution impregnation method and promoted electrochemical performance is obtained. After being coated by LC shell, the polarization resistance can be as low as 0.197 Ω cm 2 and the peak power density is 0.243 W cm −2 at the operating temperature of 600 °C. The excellent CO 2 resistance of LC-coated BSCF cathode is verified by the CO 2 -poisoning test. Even in the operating atmosphere with high CO 2 concentration, the polarization resistance change of LC-coated BSCF cathode is much smaller than that of the blank BSCF cathode. By long-term test of single cells, the remarkable electrochemical performance stability of LC-coated BSCF cathode is shown. The promoted electrochemical performance, excellent CO 2 resistance and remarkable long-term stability make LC-coated BSCF cathode promising for intermediate temperature solid oxide fuel cells.
Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 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 Cr 2 O 3 -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 0.1 Ce 0.9 O 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.