Alkali metal aqueous battery

A battery comprising:

• an anode comprising lithium or a lithium alloy;
• an anode compartment that houses the anode;
• a hydrogen gas producing cathode;
• a cathode compartment that houses the cathode;
• a LiSICON membrane that separates the anode compartment from the cathode compartment, wherein the LiSICON membrane is impermeable to water;
• an aqueous catholyte comprising lithium cations, wherein the catholyte is in fluid communication with the cathode, wherein the catholyte is housed, at least partially, within the cathode compartment;
• at least one expansion/contraction member that can expand or contract in volume, wherein the at least one expansion/contraction member is in fluid communication with the catholyte;
• a hydrogen-egress zone, wherein hydrogen produced at the cathode may vent out of the catholyte and out of the battery via the hydrogen-egress zone;
• and
• a water-ingress zone, wherein water from an environment outside the battery may ingress into the catholyte via the water-ingress zone, wherein the water-ingress zone restricts the egress of the lithium cations, wherein the water-ingress zone also restricts the ingress of cations dissolved in the water into the catholyte.

A method for protecting an alkali metal conductive membrane in a battery from fouling due to incompatible ions in a water supply, the method comprising:

• obtaining a battery, wherein the battery comprises
• an anode comprising an alkali metal or an alkali metal alloy;
• a hydrogen gas producing cathode;
• an alkali metal conductive membrane, wherein the alkali metal conductive membrane separates the anode from the cathode and is impermeable to water;
• an aqueous catholyte comprising cations of the alkali metal, wherein the catholyte is in fluid communication with the cathode;
• obtaining a hydrogen-egress zone, wherein hydrogen produced at the cathode may vent out of the catholyte and out of the battery via the hydrogen-egress zone;
• and
• obtaining a water-ingress zone, wherein water from an environment outside the battery may ingress into the catholyte via the water-ingress zone, wherein the water-ingress zone restricts the ingress of incompatible ions dissolved in the water such that the incompatible ions are prevented from contacting the alkali metal conductive membrane, wherein the water-ingress zone also restricts the egress of cations of the alkali metal.