Patent ID: 7390591

Claim:
An electrochemical device component, comprising: an active metal electrode having a first surface and a second surface; and a protective membrane on the first surface of the electrode and having a smooth gap-free interface therewith, the membrane being ionically conductive and chemically compatible with the active metal on a side in contact with the active metal electrode, and substantially impervious, ionically conductive and chemically compatible with active metal corrosive environments on the other side; wherein the ionic conductivity of the membrane is at least 10 −5 S/cm; and wherein the protective membrane comprises a composite, the composite comprising, a first material in contact with the electrode, the first material being ionically conductive and chemically compatible with the active metal, wherein the first material comprises a composite reaction product of Li with Cu 3 N, and a second material in contact with the first material, the second material being substantially impervious, ionically conductive and chemically compatible with the first material and active metal corrosive environments, the second material selected from the group consisting of glassy or amorphous metal ion conductors, ceramic active metal ion conductors, and glass-ceramic active metal ion conductors, wherein the ionic conductivity of the composite is at least 10 −5 S/cm.