Study on Microstructure and Physical Properties of Ba0.5Sr0.5Fe1−xCuxO3−δ–Ce0.8Sm0.15Ca0.05O1.875 Cathode Materials Used in Solid Oxide Fuel Cell

Ba0.5Sr0.5Fe1-xCuxO3-d (BSFCu) and BSFCu-Ce0.8Sm0.15Ca0.05O1.875 (SCDC) were prepared by solid-state reaction and sol-gel method, respectively. The possibility of BSFCu-SCDC composites as cathodes for intermediate-temperature solid oxide fuel cells (IT-SOFCs) was investigated. The results show that BSFCu has a cubic BaFeO3 structure and no secondary phase. BSFCu-SCDC has cubic BaFeO3 and Ce0.8Sm0.2O1.9 structures, and BaCeO3 secondary phase. The polarization surface specific resistance (ASRRP) of BSFCu increases with increasing Cu doping. For BSFCu-SCDC, 7BSFCu10-3SCDC has the smallest ASRRP (0.106 U cm2, 800 degrees C) at 800 degrees C-750 degrees C; at 600 degrees C - 700 degrees C, 6BSFCu10-4SCDC has the smallest ASRRP (1.043 U cm2, 600 degrees C). The maximum exchange current densities of 7BSFCu10-3SCDC and 6BSFCu10-4SCDC are about 0.219 and 0.083 A cm-2 at 800 degrees C and 700 degrees C, respectively. Compared with BSFCu, 6BSFCu10-4SCDC has a lower overpotential, which shows better electrocatalytic activity, so it can increase the energy efficiency when applied to IT-SOFC. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.