Patent ID: 7332108

Claim:
A solid-state electrolyte or mixed ionic/electronic conductor apparatus that comprises: a) a thin solid composition consisting of at least one component selected from the group consisting of ceramic and metallic material; and b) a surface concentration consisting of at least one component selected from the group consisting of ceramic and metallic material; wherein the metallic material in part a) is different from the metallic material in part b); wherein said mixed ionic/electronic conductor forms a mixed ionic/electronic conducting ceramic membrane; wherein said membrane comprises material (A) selected from the materials of the brown-millerite family of formula (III): [Mc 2-x Mc′ x ][Md 2-y Md′ y ]O 6-w (III) wherein Mc is at least one metal selected from the group consisting of alkaline-earth metals; wherein Mc′ is at least one metal selected from the group consisting of lanthanides and actinides; wherein Md is selected from the group consisting of 3d transition metals, and group 13 metals; wherein Md′ is selected from the group consisting of 3d transition metals, group 13 metals, lanthanides, and actinides; wherein x and y are identical or different, and are in the range of about 0 about 2; wherein w is such that the structure is electrically neutral; wherein a dense phase with a controlled surface porosity gradient is supported by a material (B); wherein said material (B) is at least one component selected from the group consisting of carbides, nitrides, aluminum silicates and their derivatives, calcium phosphates and their derivatives; and wherein undoped ceramic oxides provide a porous support.