Nickel substituted CuMn2O4 spinel coatings for solid oxide fuel cell interconnects

Protective CuNiMnO spinel coatings on UNS430 solid oxide fuel cells interconnects were formed by oxidizing electroplated nickel, copper, and manganese in air at 800 °C. Nickel prevented delamination and buckling damage of the coatings. Substituting copper with nickel up to 40% in CuMn2O4 spinel decreased conductivity slightly from ∼110 to ∼95 S/cm at 800 °C. XRD showed Cu0.77Ni0.45Mn1.78O4 exhibited predominantly spinel phase whereas nickel free Cu1.18Mn1.82O4 exhibited mixed oxide phase. Nickel promotes adhesion and formation of uniform protective coatings as <1 μm Cr-oxide scale formed after 120 h of oxidation and it also stabilizes the spinel phase at lower temperatures.