Evaluation of Cr-Tolerance of the Sr2Fe1.5Mo0.5O6−δ Cathode for Solid Oxide Fuel Cells

Sr2Fe1.5Mo0.5O6−δ (SFM) is a promising electrode material recently studied for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this work, Cr-tolerance of SFM has been systematically assessed. Due to the presence of Sr at the A-site, SFM has been found to be vulnerable to Cr species that resulted from the metallic interconnects. The main product of Cr-poisoning for SFM is SrCrO4 deposited on the SFM surface. Furthermore, the Cr-poisoning mechanism of the SFM material has been evaluated both experimentally and thermodynamically. To enhance Cr-tolerance of SFM, LaCoO3−δ-infiltrated SFM (LC@SFM) has been developed. LC hinders the direct contact of SFM with Cr species, and LC@SFM has significantly enhanced Cr-tolerance compared with SFM. This study provides valuable guidance for the wide application of the SFM cathode in IT-SOFCs.