Evaluation of using protective/conductive coating on Fe-22Cr mesh as a composite cathode contact material for intermediate solid oxide fuel cells

• Long-term stability of protective/conductive coating on Fe–Cr mesh was studied.
• ASR value of Fe–Cr mesh coated with LNF/interconnect interface was 0.0425(2) Ω cm2.
• Mn is concentrated on the composite surface in contact with channeled interconnect.

An uncoated and MnCo1.9Fe0.1O4 (MCF) coated Fe-22Cr meshes were dipped into LaNi0.6Fe0.4O3−δ (LNF) slurry to form a continuous protective/conductive layer for Crofer22APU interconnect. After aged these samples at 800 °C for 1000 h, energy dispersive X-ray (EDX) results concluded that: if the deposition of the protective coating was not enough to form a dense and continuous layer across the width of the mesh, then the use of MCF spinel layer is not enough to prevent chromium migration. For mesh-LNF/interconnect structure the area specific resistance (ASR) value of 0.0425(2) Ω cm2 was stable for 400 min at 800 °C, indicating initial good adherence between both materials. After aged this structure at 800 °C for 1000 h, without applying a current source, X-ray micro-diffraction (XRMD) results, performed at the rib and channel of the interconnect, revealed that the LNF material is acting as a protective layer. Moreover, X-ray photoelectron spectroscopy (XPS) analysis indicated that manganese is concentrated on the mesh/LNF contact surface.