Characterization of electrophoretically deposited nanostructured Cux(Mn, Co)3-xO4 coatings for SOFC Interconnects

Doping rare transition metals into Mn-Co spinel oxide (MCO) could improve conductivity and bonding of coated interconnects applied for solid oxide fuel cells. In the present study, Cux(Mn, Co)3-xO4 (x=0, 0.2 and 0.4) nanopowders were synthesized via sol-gel based Pechini method. Protective coatings of spinel compounds have been applied on SUS430 stainless steel interconnects by using electrophoretic deposition (EPD). The optimum condition of 1 min deposition time at 60 V was chosen according to the uniformity of coating microstructure. Kinetics of deposition was studied based on Baldisserri model at 60 V for Cu0.2MCO and Cu0.4MCO samples. The sintering of coated samples was carried out in two-steps under the both reducing and oxidizing atmospheres. The phase and microstructure of synthesized spinel nanopowders and coatings were characterized by X-ray diffraction (XRD) and fieldemission scanning electron microscopy (FE-SEM) equipped with EDS. The results of non-isothermal area specific resistance (ASR) measurements in the temperature range of 550-800oC showed the minimum value of area specific resistance (ASR)=3.2 mΩ cm2 and maximum activation energy of Ea=48.2 kJ/mole were obtained for Cu0.2MCO sample.