Rechargeable metal halide battery

Claim 2

A battery according to claim 2 wherein said halogen is bromine, and said bonding agent is a polymer inert and impermeable to bromine in concentrations present in said battery, selected from the class consisting of polyfluorocarbons, polychlorofluorocarbons, polymers of monomers containing a major portion of vinylidene chloride, poly (vinyl chloride), and poly (methyl methacrylate).

Claim 3

A battery according to claim 3 wherein said polymer is polymonochlorotrifluoroethylene.

Claim 4

A battery according to claim 1 wherein said electrode is a cathode and comprises a halogen entrapment layer, inert to halogen in concentrations present in said battery and comprising a halogen entrapping substance.

Claim 5

A battery according to claim 5 wherein said halogen is bromine and said halide entrapment layer comprises bromine absorbent particles and a bonding agent for securing said particles into an integral layer, said bonding agent being inert to bromine in concentrations present in said battery, said layer having a bromine adsorptivity of at least about 0.5 g. of bromine per gram of said layer.

Claim 6

A battery according to claim 6 wherein said bonding agent is a polymer inert and impermeable to bromine, selected from the class consisting of polyfluorocarbons, polychlorofluorocarbons, polymers of monomers containing a major portion of vinylidene chloride, poly (vinyl chloride), poly (methyl methacrylate), polyethylene, and polypropylene.

Claim 7

A battery according to claim 7 wherein said polymer is polymonochlorotrifluoroethylene.

Claim 8

A battery according to claim 6 wherein said bromine adsorbent is activated carbon.

Claim 9

A battery according to claim 1 wherein said electrode is an anode, and said barrier layer provides an electroplating surface for said metal.

Claim 10

A battery according to claim 10 wHerein said electroplatable metal is zinc and said electroplating surface has a rough texture providing a large number of electroplating sites for said metal.

Claim 11

A battery according to claim 1 wherein said electrically conductive corrodible element is formed of metal.

Claim 12

A battery according to claim 1 comprising cathodic and anodic electrodes including at least two said electrodes having said corrodible electrically conductive element and said barrier layer wherein one said electrode is a cathode comprising additionally a halogen entrapment layer, inert to halogen in concentrations present in said battery, bonded to said barrier layer, and comprising a halogen-entrapping substance, and the other said electrode is an anode, each cathodic electrode having an extended surface adapted to be located adjacent said liquid electrolyte medium, and each said anodic electrode having an electroplating surface for said metal, parallel to the adjacent extended cathode surface.

Claim 13

A battery according to claim 13 wherein the projected cross-sectional area of each extended cathode surface, projected across said battery onto the adjacent electroplating surface, is less than the cross-sectional area of said electroplating surface.

Claim 14

A battery according to claim 14 wherein the actual cross-sectional area of each extended cathode surface is less than the cross-sectional area of the adjacent electroplating surface.

Claim 15

A battery according to claim 14 including structure projecting between an extended cathode surface and an adjacent anode electroplating surface such that the projected cross-sectional area of the said extended cathode surface across said battery onto said adjacent electroplating surface is less than the actual cross-sectional area of the said extended cathode surface.

Claim 16

A battery according to claim 14 including a layer of electrical-insulating material along peripheral portions of an extended cathode surface to limit said extended surface to said projected cross-sectional area.

Claim 17

A battery according to claim 13 including a porous separator element between adjacent cathode and anode surfaces, whereby the tendency of halogen to migrate from said cathode to said anode is lessened.

Claim 18

A battery according to claim 13 wherein said battery includes at least one composite electrode intermediate of said anode and said cathode, said composite electrode comprising an electrically conductive portion inert to halogen in concentrations present in said battery, having a resistivity, Rho , such that Rho d is not greater than about 0.1 ohm-in.2, where d is the thickness of said element, and having a surface, facing said end cathode, providing an electroplating surface for said metal, and a halogen entrapment portion, bonded to said electrically conductive portion along the surface of said electrically conductive portion opposite said electroplating surface, said entrapment portion being inert to halogen in concentrations present in said battery, comprising a halogen-entrapping substance, and providing an extended surface facing said end anode, said composite electrode having a total interface resistance, per square inch of electrolyte-contacting surface areas, not greater than about 0.10 ohms.

Claim 19

A battery according to claim 19 wherein said composite electrode electroplating surface has a rough texture providing a large number of electroplating sites for said metal.

Claim 20

A battery according to claim 19 wherein said halogen is bromine.

Claim 21

A battery according to claim 21 wherein the said electrically conductive portion of said electrode comprises highly electroconductive carbon particles and a bonding agent inert to bromine in concentrations present in said battery, and said halogen-entrapment portion comprises bromine-adsorbent activated carbon particles and a bonding agent for securing said particles into an integral layer, said bonding agent being inert to bromine in concentrations present in said battery, said halogen-entrapment portion having a bromine adsorptivity of at least about 0.5 g. of bromine per gram of said portion.

Claim 22

A battery according to claim 21 wherein each said bonding agent is a polymer, inert to bromine in concentrations present in said battery, selected from the class consisting of polyfluorocarbons, polychlorofluorocarbons, polymers of monomers containing a major portion of vinylidene chloride, poly (vinyl chloride), poly (methyl methacrylate), polyethylene, and polypropylene.

Claim 23

A battery according to claim 23 wherein said electrode bonding agents are identical.

Claim 24

A battery according to claim 24 wherein said bonding agent is polymonochlorotrifluoroethylene.

Claim 25

In a rechargeable metal bromide battery, in which a salt of an electroplatable metal and a halogen selected from the group consisting of chlorine, bromine, and iodine is electrolyzed from solution in a liquid medium during the charging cycle and reformed during the discharging cycle, said battery including an end anode and an end cathode structured to provide external electrical connections for said battery, a composite electrode adapted to be located intermediate of said end anode and said end cathode in voltaic series therewith, said composite electrode comprising an electrically conductive portion comprising highly electroconductive carbon particles and a polymeric bonding agent bonding said particles together, said bonding agent being inert to said halogen in concentrations present in said battery, said conductive portion having a resistivity, Rho , such that Rho d is not greater than about 0.1 ohm-in.2, where d is the thickness of said element, and having a surface, facing said end cathode, providing an electroplating surface for said metal, and a separate bromine-adsorbent portion, bonded to said electrically conductive portion along the surface of said electrically conductive portion opposite said electroplating surface, comprising bromine-adsorbent activated carbon particles and a polymeric bonding agent for securing said particles into an integral electrode portion, said bonding agent inert to bromine in concentrations present in said battery, having a bromine adsorptivity of at least about 0.5 g. of bromine per g. of said portion, and providing an extended surface facing said end anode, the bonding agent of said conducting portion and the bonding agent of said adsorbent portion being adherent to one another to bond said portions together, said composite electrode having a total interface resistance, per square inch of electrolyte-contacting surface area, not greater than about 0.10 ohms.

Claim 26

A battery according to claim 26 wherein said composite electrode electroplating surface has a rough texture providing a large number of electroplating sites for said metal.

Claim 27

A battery according to claim 26 wherein each said bonding agent is a polymer, inert to bromine in concentrations present in said battery, selected from the class consisting of polyfluorocarbons, polychlorofluorocarbons, polymers of monomers containing a major portion of vinylidene chloride, poly (vinyl chloride), poly (methyl methacrylate), polyethylene, and polypropylene.

Claim 28

A battery according to claim 28 wherein said electrode bonding agents are identical.

Claim 29

A battery according to claim 29 wherein said bonding agent is polymonochlorotrifluoroethylene.