Interaction between metallic interconnect and constituent oxides of (La, Sr)MnO_3 coating of solid oxide fuel cells

摘要

The chemical interaction between Fe-Cr alloy interconnect and constituent oxides of Sr-doped LaMnO_3 (LSM) coating, La_2O_3, SrO and Mn_2O_3, is investigated at 800-900 deg C in air. The Cr deposition reaction between the Fe-Cr alloy metallic interconnect and oxides varies significantly with the nature of the oxides. The interaction between the Fe-Cr alloy and La_2O_3 and Mn_2O_3 oxide coatings primarily results in the formation of LaCrO_3 and (Cr, Mn)_3O_4 while in the case of SrO oxide coating, Cr_2O_3 is the main product. In the case of LSM coating, the formation of (Cr, Mn)_3O_4 and Cr_2O_3 is identified. The results indicate that the chemical interaction between the Fe-Cr alloy interconnect and LSM coating is most likely related to the surface oxide species such as SrO and MnO_x initially enriched or segregated on the surface of LSM particularly in the early stages of the reaction.