# US 2008/0187824 A1 · Composite current collector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0187824 A1 - Document ID: US20080187824A1 - Status: Published application - Kind: A1 - Application number: 12/024,139 - Filed: 2008-02-01 - Published: 2008-08-07 - Earliest claimed: 2007-02-07 - Assignees: Rosecreek Technologies Inc. - Inventors: Klaus Tomantschger - Web page: https://patentgrep.com/patent/US20080187824A1 ## CPC - H01M 4/667: {in the form of layers, e.g. coatings} - H01M 4/14: Electrodes for lead-acid accumulators - H01M 4/244: {Zinc electrodes} - H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)} - H01M 4/662: {Alloys (collectors of lead alloys H01M4/685)} - H01M 4/742: {perforated material} - H01M 6/06: Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid - H01M 10/06: Lead-acid accumulators (semi-lead accumulators H01M10/20) - H01M 10/24: Alkaline accumulators - H01M 4/72: Grids - H01M 4/74: Meshes or woven material; Expanded metal - H01M 4/765: {Tubular type or pencil type electrodes; tubular or multitubular sheaths or covers of insulating material for said tubular-type electrodes} - H01M 4/78: Shapes other than plane or cylindrical, e.g. helical - H01M 4/808: {Foamed, spongy materials} - H01M 2200/103: Fuse - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Composite current collectors containing coatings of metals, alloys or compounds, selected from the group of Zn, Cd, Hg, Ga, In, Tl, Sn, Pb, As, Sb, Bi and Se on non-metallic, non-conductive or poorly-conductive substrates are disclosed. The composite current collectors can be used in electrochemical cells particularly sealed cells requiring a long storage life. Selected metals, metal alloys or metal compounds are applied to polymer or ceramic substrates by vacuum deposition techniques, extrusion, conductive paints (dispersed as particles in a suitable paint), electroless deposition, cementation; or after suitable metallization by galvanic means (electrodeposition or electrophoresis). Metal compound coatings are reduced to their respective metals by chemical or galvanic means. The current collectors described are particular suitable for use in sealed primary or rechargeable galvanic cells containing mercury-fee and lead-free alkaline zinc electrodes. ## Claims ### Claim 1 An electrochemical cell comprising a composite current collector having a density in the range of 0.1 to 10 g/cm3, said composite current collector comprising a metallic layer on a polymer substrate characterized by: (i) said metallic layer being (1) an alloy of two or more metals or (2) at least one metal selected from the group of Zn, Cd, Hg, Ga, In, Tl, Sn, Pb, As, Sb, Bi and Se; and (ii) said metallic layer having a thickness in the range of 1 and 5,000 microns. ### Claim 2 (depends on 1) An electrochemical cell comprising a composite current collector according to claim 1 wherein said polymer substrate is selected from the group of filled or unfilled epoxy resin composites; epoxy resins; cellulose based materials; thermoplastic polyolefins (TPOs); thermoplastic polyester resins; thermoplastic polyester elastomers; crystalline, semi-crystalline and amorphous polymers; cellulose based materials; polyethylene; polypropylene; polyvinyl chloride (PVC); polytetrafluoroethylene (PTFE); polystyrene; acrylonitrile-butadiene-styrene (ABS); polyphthalamide (PPA), polycarbonate (PC), polyamide (PA), polyester (PET, PBT), polyacetals (POM); liquid crystal polymers (LCP), polyphenylene sulfide (PPS), polysulfone (PS) and polyetherimide (PEI); and wherein said polymer substrate contains between 0% and 75% per volume and/or weight of one or more filler materials selected from the group of (1) at least one metal, (2) a metal alloy or (3) at least one compound, selected from the group of Zn, Cd, Hg, Ga, In, Tl, Sn, Pb, As, Sb, Bi and Se. ### Claim 3 (depends on 1) An electrochemical cell according to claim 1, which is a sealed lead-acid cell or battery, and wherein said composite current collector has a density in the range of 1 to 10 g/cm3, said metallic coating has a thickness in the range of 1 to 5,000 microns and wherein the voltage drop along the entire height of said composite current collector at an applied current of 100 Amperes ranges from 1 mV to 1 V. ### Claim 4 (depends on 1) An electrochemical cell according to claim 1, which is a sealed galvanic cell comprising a zinc negative electrode which is substantially free of Hg, Cd and Pb, said zinc negative electrode comprising the composite current collector, the composite current collector being substantially free of Cu and Fe and having a density in the range of 0.1 to 6 g/cm3, and comprising a metallic layer on a polymer substrate characterized by: (i) said metallic layer being (1) an alloy of two or more metals or (2) at least one metal, selected from the group of Zn, Ga, In, Tl, Sn, As, Sb, Bi and Se; and (ii) said metallic layer having a thickness in the range of 1 and 500 microns. ### Claim 5 (depends on 4) An electrochemical cell according to claim 4, wherein said metallic layer is selected from the group of In, Sn or In—Sn alloys, said composite current collector has a density between 0.1 and 3 g/cm3 and the voltage drop across the entire height of said composite current collector at an applied current of 1 Ampere is between 1 mV and 250 mV. ### Claim 6 (depends on 1) An electrochemical cell according to claim 1, wherein the polymer substrate surface is rendered conductive by applying a conductive paint containing (1) at least one metal, (2) a metal alloy or (3) at least one compound, selected from the group of Zn, Cd, Hg, Ga, In, Tl, Sn, Pb, As, Sb, Bi and Se. ### Claim 7 (depends on 2) An electrochemical cell according to claim 2, wherein said filler material in said polymer substrate is at least one compound selected from the group of Zn, Cd, Hg, Ga, In, Tl, Sn, Pb, As, Sb, Bi and Se which is subsequently reduced to its metallic form on and near the outer surface of said polymer substrate. ### Claim 8 (depends on 1) An electrochemical cell according to claim 1, wherein said metallic coating is built up to its desired thickness by electrodeposition, electroless deposition, electrophoretic deposition, PCD, CVD, sputtering, cold or hot spraying of powders or melts or said metallic coating is attached to the substrate using an adhesive. ### Claim 9 (depends on 1) An electrochemical cell according to claim 1 wherein said metallic layer has a tapered thickness profile characterized by having the highest thickness in the vicinity of the post. ### Claim 10 (depends on 1) An electrochemical cell according to claim 1, wherein said composite current collector has the shape of a nail, tube, foil, plate, woven mesh, expanded mesh or more complex shape selected from the group consisting of spiral, blade, formed or bent foil or tube, book mold type grid, radial grid, expanded grid, punched foil, perforated foils and open cell foam. ### Claim 11 (depends on 4) An electrochemical cell according to claim 4, wherein said composite current collector is suitably perforated or hollowed to provide space for gas expansion, additional electrolyte, active electrode material or gas recombination device or devices. ### Claim 12 (depends on 4) An electrochemical cell according to claim 4, which contains a positive electrode comprising at least one active material selected from the group of manganese dioxide, nickel oxides and oxygen. ### Claim 13 (depends on 12) An electrochemical cell according to claim 12, which is a cylindrical cell. ### Claim 14 (depends on 13) An electrochemical cell according to claim 13, which contains a hydrogen recombination catalyst. ### Claim 15 (depends on 4) An electrochemical cell according to claim 4, which after 6 years of storage at room temperature and/or 4 weeks at 65° C. has a pass rate with respect to leakage/frosting of over 85% with respect to leakage/frosting and has a discharge capacity retention of more than 10%. ### Claim 16 (depends on 4) An electrochemical cell according to claim 4, which after 6 years of storage at room temperature has a discharge capacity retention of more than 10%. ### Claim 17 (depends on 4) An electrochemical cell according to claim 4, wherein the composite current collector limits the short circuit current of the cell when expressed in Amperes to a value between 50% and 100% of the value of the zinc amount expressed in grams. ### Claim 18 (depends on 4) An electrochemical cell according to claim 4, wherein the composite current collector acts as a fuse and at least a portion of said metallic layer melts at a predetermined current disrupting the current flow in and out of the galvanic cell. ### Claim 19 (depends on 1) An electrochemical cell according to claim 1, which contains an active electrode material, said active electrode material containing composite conductive particles selected from the group of flakes, needles or platelets, and wherein said composite conductive particles are in electrical contact with said composite current collector. ### Claim 20 (depends on 19) All electrochemical cell according to claim 19, wherein said composite conductive particles represent between 0.1-25% of the volume or of the weight of said active material.