Synthesis and characterization of Bi1-xSrxFeO3-δ (BSFO) nanofibers as cathodes for intermediate-temperature solid oxide fuel cells

Bi1-xSrxFeO3-delta (BSFO, x = 0, 0.1, 0.2, 0.3, 0.4) nanofibers were prepared by the electrospinning technology and evaluated as cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs). With the increase of Sr doping, the crystal structure changes from rhombohedral to cubic and the average diameter of the fibers decreased from 150 nm to 119 nm. When x = 0.3, BSFO nanofibers possess the lowest polarization resistance (0.137 Omega cm(2) at 650 degrees C, 0.061 Omega cm(2) at 700 degrees C), more than 75% smaller than that of BSFO nanopowders with the same composition (0.771 Omega cm(2) at 650 degrees C, 0.282 Omega cm(2) at 700 degrees C). The maximum power density of single cells with BSFO nanofiber cathode reaches up to 663.81 mW cm(-2) at 700 degrees C using wet hydrogen (3 wt%) as fuels. The combination of element doping and microstructure optimizing is proven to be an effective approach for developing high-performance cathodes for IT-SOFCs. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.