Chromia scale thickness affect on electrical conductivity of SOFC interconnects

Recent research, has concentrated on the application of protective/conductive coatings on the surface of used interconnects in solid oxide fuel cells. In this study AISI 430 ferritic stainless steel interconnect was coated in a manganese-base pack mixture by pack cementation. The effect of oxide scale thickness on the electrical conductivity was evaluated by applying isothermal oxidation. This effect was also investigated in different temperatures (400–700°C). Spinels forming (Mn₃O₄ and MnFe₂O₄) during annealing ameliorated oxidation resistance and electrical conductivity. Results showed that the increase of isothermal oxidation time and increase of temperature, increases the oxide thickness and it redounded to the higher lower values of electrical conductivity.