| abstract |
The present invention provides a solid oxide fuel cell having high conductivity, high catalytic activity, minimizing thermal expansion (CTE) mismatch, excellent compatibility with other parts of the fuel cell, and reduced operating temperature. The present invention relates to a multilayer multifunctional cathode. The cathode includes a conductive layer, a catalyst layer, and a graded composition layer. The conductive layer has a first density, the catalyst layer has a second density smaller than the first density, and the graded composition layer is characterized by a gradual change in electron conductivity and ionic conductivity. The conductive layer is made of one or more rare earth metals of Ca, Sr, Mg and Ba as A, a transition metal as B, one or more rare earth metals as C, and one or more tetravalent ions as D. And when d is a number from 0 to 1, it includes a material selected from the group consisting of ABO 3 ± d , A 2 B 2 O 5 ± d and C 2 D 2 O 7 ± d . |