Interconnects employed in solid oxide fuel cells require electrically conductive protective coatings such as those based on manganese cobalt oxide spinels in order to prevent evaporation of volatile Cr(VI)-compounds and to minimize high temperature corrosion. MnCo2−xFexO4 based (where x = 0.1 and 0.3) oxide spinel protective coatings were manufactured by the atmospheric plasma spraying process on Crofer 22 APU substrates. The coated substrates were oxidized at 700 °C in air for 1000 h and post-mortem analyses were conducted to study the performance of the thermal sprayed coatings. During the high temperature oxidation, a four-point on-line measurement technique was used for area specific resistance studies. The MnCo1.7Fe0.3O4 coating was tested together with the La0.85Sr0.15Mn1.1O3-spacer. The atmospheric plasma sprayed MnCo2−xFexO4 showed excellent Cr-barrier properties and decreased oxidation of the substrate. In addition, resistance as low as 9.20 mΩ cm2 values was obtained after the 1000 h oxidation cycle. The MnCo1.9Fe0.1O4 coating manufactured by the atmospheric plasma spraying process is a promising candidate for SOFC interconnect applications.
Post-mortem evaluation of oxidized atmospheric plasma sprayed Mn–Co–Fe oxide spinel coatings on SOFC interconnectors / Puranen, Jouni; Pihlatie, Mikko; Lagerbom, Juha; Bolelli, Giovanni; Laakso, Jarmo; Hyvärinen, Leo; Kylmälahti, Mikko; Himanen, Olli; Kiviaho, Jari; Lusvarghi, Luca; Vuoristo, Petri. - In: INTERNATIONAL JOURNAL OF HYDROGEN ENERGY. - ISSN 0360-3199. - STAMPA. - 39:(2014), pp. 17284-17294. [10.1016/j.ijhydene.2014.08.105]