Electrical stability of a novel sealing glass with (Mn,Co)-spinel coated Crofer22APU in a simulated SOFC dual environment

A novel alkaline-earth silicate (Sr–Ca–Y–B–Si–Zn) sealing glass was developed for solid oxide fuel cell (SOFC) applications. The glass was sandwiched between two metallic interconnect plates and tested for electrical stability in a dual environment at elevated temperatures of 800–850 °C. A ferritic stainless steel (Crofer22APU) was used as the metallic interconnect material in the as-received state and coated with (Mn,Co)3O4 spinel. The isothermal aging results showed stable electrical resistivity at 800–850 °C for ∼500–1000 h. The electrical resistivities at 800 or 850 °C of the spinel coated samples were lower than the as-received ones; however, they were still several orders of magnitude higher than typical SOFC functional parts. Interfacial microstructure was characterized and possible reactions are discussed.