Active metal/aqueous electrochemical cells and systems

A battery cell, comprising:

• an active metal anode comprising lithium having a first surface and a second surface;
• a cathode structure comprising an electronically conductive component, an ionically conductive component, and an electrochemically active component, wherein at least one cathode structure component comprises an aqueous constituent;
• an ionically conductive protective membrane on the first surface of the anode, the membrane comprising,
• a first material component in contact with the anode that is ionically conductive and chemically compatible with lithium, the first material component comprising a material selected from the group consisting of a composite reaction product of lithium with a Cu3N, a composite reaction product of lithium with PbI2, and a reaction product of lithium with red phosphorus, and
• a second material component in contact with the first material component, the second material being substantially impervious, ionically conductive and chemically compatible with the first material component and the cathode structure, the second material component selected from the group consisting of ceramic active metal ion conductors and glass-ceramic active metal ion conductors.