A single-step synthesized cobalt-free barium ferrites-based composite cathode for intermediate temperature solid oxide fuel cells

Cobalt-free perovskite cathode with excellent oxygen reduction reaction (ORR) properties below 800 °C is a key material toward wide implementation of intermediate-temperature solid oxide fuel cells. This work reports the phase structure, microstructure and performance of such cathode based on the composite phases of triclinic Ba0.9Bi0.1FeO3-δ, cubic BaFeO3 and orthorhombic BaFe2O4 prepared by sol–gel route. The resultant barium ferrites composite cathode exhibits uniform particles, pores and elements distribution. In particular, favorable ORR properties of this cathode is demonstrated by very low interfacial resistance of only 0.036 and 0.072 Ω cm2 at 750 and 700 °C and maximum power density of 1295 and 840 mW cm−2 at 750 and 700 °C.

► Cobalt-free barium ferrites composite cathode prepared by sol-gel route in single step.
► The composite cathode shows homogeneous distribution of elements and uniform microstructure.
► The composite cathode demonstrates an interfacial resistance of only 0.036 Ω cm2 at 750°C.
► A single fuel cell with the composite cathode shows a peak power density of 1295 mW cm-2 at 750°C.