Cu1.3Mn1.7O4/LaNi0.6Fe0.4O3 composite with prospects for IT-SOFC/SOEC applications

Composite materials with the composition (100-x)Cu1.3Mn1.7O4/xLaNi0.6Fe0.4O3 (CMxLNF, where: x= 5, 10, 15, 20, 30, 40 and 50 wt%) were evaluated as possible coating materials for SOFC/SOEC metallic interconnects. The introduction of LaNi0.6Fe0.4O3 into spinel matrices improved electrical conductivity compared to pure Cu1.3Mn1.7O4. The measured Seebeck coefficient values indicate that carrier concentration increased with LaNi0.6Fe0.4O3 content, yet the activation energy of the carriers' mobility decreased. Extensive structural and microstructural studies of selected CM/LNF systems showed that composite material components exhibited high stability in relation to one another. Additionally, LaNi0.6Fe0.4O3 significantly improved the chemical stability of Cu1.3Mn1.7O4 in the presence of chromia, as tested after 150 h of exposure to air at 800 °C. Finally, coatings based on selected composite powders were deposited electrophoretically on the steel and were oxidized for 1500 h in air at 750 °C, confirming that CM10LNF can be applied as effective protective-conducting coatings on low-chromium ferritic steel.