Development of MnCoO coating with new aluminizing process for planar SOFC stacks

Chromia-forming ferritic stainless steels find widespread use as interconnect materials in SOFCs at operating temperatures below 800 °C, because of their thermal expansion match and low cost. However, volatile Cr-containing species originating from this scale can poison the cathode material in the cells and subsequently cause power degradation in the devices. To prevent this, a conductive manganese cobaltite spinel coating has been developed, but unfortunately; this coating is not compatible with glass-based seals between the interconnect or cell frame components and the ceramic cell due to reactions between the coating and the glass. Thus, a new aluminizing process has been developed to improve the stability of the sealing regions of these components, as well as for other metallic stack and balance-of-plant components.