Oxygen non-stoichiometry and mixed conductivity of Ti-doped BaCo0.4Fe0.4Y0.2O3-s perovskite

The mixed electronic-ionic conducting (MIEC) perovskite materials are promising as a cathode of solid oxide fuel cells (SOFCs). According to recent reports, BaCo0.4Fe0.4Zr0.2O3-s (BCFZ) and its doped compounds exhibit po-tentiality under the SOFCs operating conditions at intermediate-low temperatures. The structural, oxygen non-stoichiometry, electrical conductivity, and oxygen permeability properties of Ti-doped BaCo0.4Fe0.4Y0.2O3-s was characterized and then compared with those of BaCo0.4Fe0.4Y0.2O3-s or Mg-doped BaCo0.4Fe0.4Y0.2O3-s. The cubic symmetry with space group Pm-3m crystallizes in all the prepared samples. The Ti-doped sample displayed the highest total electrical conductivity of 3.19 S cm-1 at 800 degrees C, which is higher than the conductivity of the Mg-doped sample (2.52 S cm-1). The oxygen permeability of Ti and Mg-doped samples are 0.46 and 0.48 mu mol cm-2 s- 1 at 800 degrees C, respectively. The obtained MIEC (total electronic and oxygen ion conductivities) is higher compared to the BaCo0.4Fe0.4Y0.2O3-s (total electrical conductivity of 2.9 S cm-1 and oxygen permeability of 0.26 mu mol cm-2 s- 1) potential cathode within the intermediate temperature-based SOFCs. Thus, this work proposes that Ti-doped perovskite could be a new cathode candidate for SOFCs, concerning structural stability and high mixed electronic-ionic conductivity.

Automated summary

MIEC perovskite materials show promising potential as cathodes in solid oxide fuel cells (SOFCs), with Ti-doped samples displaying the highest electrical conductivity and oxygen permeability. This work suggests that Ti-doped perovskite could be a new cathode candidate for SOFCs, offering structural stability and high mixed electronic-ionic conductivity.