A permeation model study of oxygen transport kinetics ofBaxSr1-xCo0.8Fe0.2O3-δ

BaxSr1-xCo0.8Fe0.2O3-delta(BSCF) materials with different Ba doping amounts are widely applied as membranes for oxygen separation and electrodes in solid oxide cells. Different opinions were put forward about the effect of Ba contents on the oxygen transport kinetics. In this work, an oxygen permeation model was first used to investigate the effect of Ba content in BSCF (x= 0, 0.1, 0.3, 0.5, 0.7) on the oxygen transport kinetics. The permeation resistance constants were obtained separately through fitting the condition experimental data to the model. With the increase of Ba content, the interfacial oxygen exchange resistance constants of both sides decrease quickly and then increase slightly, while bulk diffusion resistance remains monotone decreasing. The improvement of oxygen permeation flux is mainly contributed by the enhancement of interfacial oxygen exchange kinetics. It is inferred that Ba element may play an important role in the interfacial oxygen reactions.