SrFe0.8Mo0.2O3-δ : Cathode material for intermediate temperature solid oxide fuel cells.

As a mixed oxygen ionic and electronic conductor, SrFe0.8Mo0.2O3-δ is confirmed to be a good cathode material for intermediate-temperature solid-state fuel cells (IT-SOFCs). The sample of SrFe0.8Mo0.2O3-δ is synthesized by a solid-state reaction method. Pure cubic SrFe0.8Mo0.2O3-δ perovskite, with space group of Pm-3m (no. 221) and lattice parameter a =3.9120(1) Å, is determined via Powder X-ray Rietveld refinements. X-ray photoelectron spectroscopy testifies the existence of mixed oxidation states Fe2+/3+/4+ and Mo5+/6+ in the crystal. Thermogravimetry analysis consistently shows that the SrFe0.8Mo0.2O3-δ begins to the loss of lattice oxygen at about 450°C, which overlaps to the inflection temperature of the electrical conductivity profile. The maximum electrical conductivity obtained is about 50.20Scm−1 at 450°C, and the impedance 0.11 Ω cm2 at 850°C. The performance demonstrates that SrFe0.8Mo0.2O3-δ is a potential candidate as a cathode material for IT-SOFCs. [ABSTRACT FROM AUTHOR]