Electrochemical characteristics of Ba0.5Sr0.5Co0.8Fe0.2O3−δ-Sm0.2Ce0.8O1.9 composite materials for low-temperature solid oxide fuel cell cathodes

In this paper, Ba0.5Sr0.5Co0.8Fe0.2O3−δ-xSm0.2Ce0.8O1.9 (BSCF-xSDC, x = 0-60 wt.%) composite cathodes were prepared by soft chemical methods, and then examined for potential applications in lower temperature solid oxide fuel cells. Both DC polarization and AC impedance spectroscopy measurements indicated that the addition of SDC electrolyte into BSCF remarkably improved the electrochemical properties. The optimum composition was found to be BSCF-30SDC, which exhibited 5.5 times higher polarization current density and 15.1% polarization resistance, compared with the pure-phase BSCF cathode at 550 °C.