Low-temperature fabrication of (Ba,Sr)(Co,Fe)O₃ cathode by the reactive sintering method

抄録

In this study, we prepare Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3–δ (BSCF) cathodes using the reactive sintering method. BSCF is known as a candidate for cathode material of intermediate temperature solid oxide fuel cell. This BSCF cathode is fabricated on the anode supported cells at a low-temperature of 700°C in order to overcome a crystal phase transition from cubic to hexagonal. Utilizing the reactive sintering, hexagonal BSCF cathode can be synthesized and sintered at 700°C by using the intermediate compound of BSCF. In addition, the reactive sintering can improve the sinterability of BSCF and decrease the ohmic and polarization resistances of the cells. The anode supported cell having hexagonal BSCF cathode shows a good power output, compared with the sample made from a commercial cubic BSCF powder. Its maximum power output reaches to ca. 1 W cm⁻² at 700°C. It is considered that the reactive sintered BSCF cathode layer has a good interface with gadolinium doped ceria interlayer. It is found the hexagonal BSCF has good cathode properties if the cathode sintered well at low-temperature.