CA2507399C - Method for producing drawn coated metals and use of said metals in the form of a current differentiator for electrochemical components - Google Patents
Method for producing drawn coated metals and use of said metals in the form of a current differentiator for electrochemical components Download PDFInfo
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- CA2507399C CA2507399C CA2507399A CA2507399A CA2507399C CA 2507399 C CA2507399 C CA 2507399C CA 2507399 A CA2507399 A CA 2507399A CA 2507399 A CA2507399 A CA 2507399A CA 2507399 C CA2507399 C CA 2507399C
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- coating
- expanded metal
- foil
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- 229910052751 metal Inorganic materials 0.000 title claims abstract description 98
- 239000002184 metal Substances 0.000 title claims abstract description 98
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- 150000002739 metals Chemical class 0.000 title abstract description 27
- 239000011888 foil Substances 0.000 claims abstract description 65
- 238000000576 coating method Methods 0.000 claims abstract description 50
- 239000011248 coating agent Substances 0.000 claims abstract description 47
- 238000000034 method Methods 0.000 claims abstract description 38
- 230000008569 process Effects 0.000 claims abstract description 25
- 239000007772 electrode material Substances 0.000 claims abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 17
- 239000000725 suspension Substances 0.000 claims description 17
- 239000010439 graphite Substances 0.000 claims description 13
- 229910002804 graphite Inorganic materials 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 12
- 229910052782 aluminium Inorganic materials 0.000 claims description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 10
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 9
- 239000011230 binding agent Substances 0.000 claims description 8
- 229920000620 organic polymer Polymers 0.000 claims description 8
- 238000004080 punching Methods 0.000 claims description 7
- 239000003575 carbonaceous material Substances 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 229910052744 lithium Inorganic materials 0.000 claims description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical group [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 4
- 239000011148 porous material Substances 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 239000004332 silver Substances 0.000 claims description 3
- 238000004528 spin coating Methods 0.000 claims description 3
- 238000003618 dip coating Methods 0.000 claims description 2
- 229920000592 inorganic polymer Polymers 0.000 claims description 2
- 239000000843 powder Substances 0.000 claims description 2
- 238000004381 surface treatment Methods 0.000 claims description 2
- 238000005096 rolling process Methods 0.000 claims 1
- 239000002318 adhesion promoter Substances 0.000 description 12
- 239000007788 liquid Substances 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- 230000008901 benefit Effects 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 5
- 238000003475 lamination Methods 0.000 description 5
- 239000002131 composite material Substances 0.000 description 4
- 239000011889 copper foil Substances 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 238000009830 intercalation Methods 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- 230000002349 favourable effect Effects 0.000 description 3
- 239000011244 liquid electrolyte Substances 0.000 description 3
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- 239000004014 plasticizer Substances 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 229920001169 thermoplastic Polymers 0.000 description 3
- 239000004416 thermosoftening plastic Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 239000002033 PVDF binder Substances 0.000 description 2
- 239000006230 acetylene black Substances 0.000 description 2
- 239000000084 colloidal system Substances 0.000 description 2
- 230000032798 delamination Effects 0.000 description 2
- -1 for example Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000002687 intercalation Effects 0.000 description 2
- 238000010030 laminating Methods 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000009828 non-uniform distribution Methods 0.000 description 2
- 229920005569 poly(vinylidene fluoride-co-hexafluoropropylene) Polymers 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910032387 LiCoO2 Inorganic materials 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- CVJYOKLQNGVTIS-UHFFFAOYSA-K aluminum;lithium;titanium(4+);phosphate Chemical compound [Li+].[Al+3].[Ti+4].[O-]P([O-])([O-])=O CVJYOKLQNGVTIS-UHFFFAOYSA-K 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000010406 cathode material Substances 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 229920001973 fluoroelastomer Polymers 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910001009 interstitial alloy Inorganic materials 0.000 description 1
- 229910000664 lithium aluminum titanium phosphates (LATP) Inorganic materials 0.000 description 1
- 229910000625 lithium cobalt oxide Inorganic materials 0.000 description 1
- 229910003002 lithium salt Inorganic materials 0.000 description 1
- 159000000002 lithium salts Chemical class 0.000 description 1
- BFZPBUKRYWOWDV-UHFFFAOYSA-N lithium;oxido(oxo)cobalt Chemical compound [Li+].[O-][Co]=O BFZPBUKRYWOWDV-UHFFFAOYSA-N 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000002931 mesocarbon microbead Substances 0.000 description 1
- 238000010327 methods by industry Methods 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920002959 polymer blend Polymers 0.000 description 1
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 1
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 1
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 238000007763 reverse roll coating Methods 0.000 description 1
- 238000007761 roller coating Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 230000009974 thixotropic effect Effects 0.000 description 1
- 210000002105 tongue Anatomy 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
- C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
- C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D31/00—Other methods for working sheet metal, metal tubes, metal profiles
- B21D31/04—Expanding other than provided for in groups B21D1/00 - B21D28/00, e.g. for making expanded metal
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
- H01M10/0562—Solid materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0404—Methods of deposition of the material by coating on electrode collectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0409—Methods of deposition of the material by a doctor blade method, slip-casting or roller coating
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0414—Methods of deposition of the material by screen printing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0402—Methods of deposition of the material
- H01M4/0416—Methods of deposition of the material involving impregnation with a solution, dispersion, paste or dry powder
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/24—Electrodes for alkaline accumulators
- H01M4/26—Processes of manufacture
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/66—Selection of materials
- H01M4/661—Metal or alloys, e.g. alloy coatings
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/64—Carriers or collectors
- H01M4/70—Carriers or collectors characterised by shape or form
- H01M4/72—Grids
- H01M4/74—Meshes or woven material; Expanded metal
- H01M4/745—Expanded metal
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M6/00—Primary cells; Manufacture thereof
- H01M6/04—Cells with aqueous electrolyte
- H01M6/06—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid
- H01M6/10—Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid with wound or folded electrodes
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/30—Foil or other thin sheet-metal making or treating
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/30—Foil or other thin sheet-metal making or treating
- Y10T29/301—Method
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/4998—Combined manufacture including applying or shaping of fluent material
- Y10T29/49982—Coating
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Dispersion Chemistry (AREA)
- Mechanical Engineering (AREA)
- General Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Metallurgy (AREA)
- Physics & Mathematics (AREA)
- Cell Electrode Carriers And Collectors (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Electrolytic Production Of Metals (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Secondary Cells (AREA)
- External Artificial Organs (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Laminated Bodies (AREA)
Abstract
The present invention pertains to a process for manufacturing expanded metal provided with a coating, characterized in that the coating is applied to a closed metal foil and this is converted into expanded metal only after the coating. In particular, the coating may be a coating that improves the adhesiveness of the expanded metal to an electrode material and/or the electron conductivity on the surface of the expanded metal. Such expanded metals can be advantageously used as current collectors in or for an anode foil or in or for a cathode foil, e.g., in an electrochemical cell, especially in a battery.
Description
Method for Producing Drawn Coated Metals and Use of Said Metals in the Form of a Current Differentiator for Electrochemical Components The present invention pertains to a process for manufacturing coated expanded metals, which are suitable for use, among other things, as current collectors in electrochemical components, especially in nonaqueous electrochemical cells.
Typical representatives of nonaqueous electrochemical cells are lithium batteries. These have been known in various embodiments for a long time and have been described several times. The design of these cells is as follows: An anode, either one consisting of lithium metal or graphite, is arranged opposite a cathode, usually a stable lithium interstitial compound.
The two electrodes are separated by a separator. The complete system is interspersed by an electrolyte, which establishes the ionic conductivity for lithium ions. They are formed, as a rule, by a lithium salt dissolved in one or more organic solvents. Lithium ions move to and fro between the electrodes during charging and discharging.
To avoid the problem of unbound electrolyte liquids inside the battery body, successful attempts were made at making the electrodes and the separator in the form of foils.
These foils are characterized either by a high microporosity, in which the liquid electrolyte is immobilized, or by the addition of suitable polymers, which form a gel with the liquid.
Besides the electrochemical components described, such components require current collectors to collect and drain off the electron current and make is usable for the user.
The current collectors are metals, which are introduced either as foils or as expanded metals. They shall meet a number of conditions, namely, (a) they must be electrochemically stable against corrosion, (b) they shall have good contact with the particular electrodes to ensure a low contact resistance, (c) they shall have a low weight in order to guarantee high energy densities, and (d) they shall have favorable elastic properties in order to compensate variations in volume during the intercalation and de-intercalation of lithium ions in the electrodes during the operation. Aluminum and graphite have proved to be suitable for use as metals that are stable in the electrochemical environment of the battery for the system used commonly with lithium cobalt oxide as the cathode material and graphite on the anode side. However, the process being described here is not limited to these metals.
The manufacture of expanded metals shall be briefly explained below. The process is schematically shown in Figure 1. Metal foils (1) of a suitable thickness are provided with a punched pattern in a punching tool (2) and then stretched (3). The geometric data of the expanded metal, such as the width of the web, the opening diagonals and the percentage of open area are set by designing the punched pattern and the rate of stretching.
The advantages of the use of expanded metals as current collectors are obvious: Compared to foils, they have an open-pore structure, so that the weight of the current collectors can be reduced, which entails advantages in the gravimetric energy density. In addition, the expanded metal is elastic in such a way that it can follow the changes in volume during the intercalation and de-intercalation of lithium in the electrodes, without delamination taking place. Delamination would in turn reduce the cycle life of the batteries.
Another advantage is achieved in terms of production engineering when expanded metal is used in lithium-polymer batteries. This type of battery is usually manufactured as follows: The electrodes are either deposited directly on metal foils (see US 6,306,215) or are laminated on the current collector by lamination under pressure and optionally under the action of temperature (DE 199 52 335). A firm composite of the three different foils for the anode with the current collector, the separator and the cathode with the current collector is then prepared in a second step by lamination or by the winding technique. This composite is then impregnated with electrolyte liquid. The electrolyte liquid must be distributed uniformly in the complete foil composite. This is achieved essentially by capillary forces. This process is frequently also supported by the additional formation of pores, which are produced by adding a plasticizing agent to the electrode and separator materials, which is again removed by means of a solvent after the components have been laminated together. Closed metal foils make difficult the penetration of the liquid electrolyte into the battery body, i.e., they prolong the duration of the process. The use of an open-mesh expanded metal therefore offers considerable advantages in terms of process engineering.
To achieve good adhesion and low contact resistance at the interface between the metallic current collector and the laminated electrode, it proved to be advantageous to coat the current collector with a thin layer of adhesion promoter before it is connected to the electrode, and it is especially advantageous if the said adhesion promoter layer has an electron conductivity.
A number of proposals have been made in the state of the art concerning the technique to be used to apply such adhesion promoters and their suitable compositions. They comprise the coating of current collectors made of expanded metals or of other perforated collectors (nettings, grids) in liquids or pastes by spin coating, dipping or coating (see US 6,306,215 and US 5, 824,120), the application of a layer that contains carbon powder and an adhesiveness-improving polymer, by means of electrostatic forces (US 5,542,163), or a plasma polymerization method, by which a layer of an electrically conductive, polymeric, adhesion-improving material is applied to the current collector (see US 6,007,588). All the documents mentioned describe electrochemical cells from electrode materials with a plasticizing agent, which is again washed out of the cells after the individual components (electrode and separator layers or foils, current collector) have been laminated together in order to generate pore volume for the electrolyte liquid, as was described above. It is also possible to apply the coating by applying a suitable suspension by means of printing methods.
Corresponding suspensions are commercially available. Methods based on the use of printing rollers, for example, reverse roll coating, are used. The suspensions consist, as a rule, of a carbon/polymer mixture in a suitable solvent, such as water.
Considerable problems arise in practical application when coating solutions are applied according to methods used in the printing trade. The layer thickness of the suspensions applied are usually between approx. 1 pm and approx. 20 pm. Insufficient wetting is invariably observed in the printing roller process, which leads to nonuniform distribution of the suspension on the metal. As a result, the contact resistance increases or contact is even lost between the current collector and the electrode at the poorly coated sites during the operation of electrochemical components equipped with expanded metals coated in this manner, e.g., batteries, and this has disadvantageous consequences for the service life of the components. However, the use of thicker adhesion promoter layers is ruled out because of the undesired reduction of the energy density that is associated with this.
Typical representatives of nonaqueous electrochemical cells are lithium batteries. These have been known in various embodiments for a long time and have been described several times. The design of these cells is as follows: An anode, either one consisting of lithium metal or graphite, is arranged opposite a cathode, usually a stable lithium interstitial compound.
The two electrodes are separated by a separator. The complete system is interspersed by an electrolyte, which establishes the ionic conductivity for lithium ions. They are formed, as a rule, by a lithium salt dissolved in one or more organic solvents. Lithium ions move to and fro between the electrodes during charging and discharging.
To avoid the problem of unbound electrolyte liquids inside the battery body, successful attempts were made at making the electrodes and the separator in the form of foils.
These foils are characterized either by a high microporosity, in which the liquid electrolyte is immobilized, or by the addition of suitable polymers, which form a gel with the liquid.
Besides the electrochemical components described, such components require current collectors to collect and drain off the electron current and make is usable for the user.
The current collectors are metals, which are introduced either as foils or as expanded metals. They shall meet a number of conditions, namely, (a) they must be electrochemically stable against corrosion, (b) they shall have good contact with the particular electrodes to ensure a low contact resistance, (c) they shall have a low weight in order to guarantee high energy densities, and (d) they shall have favorable elastic properties in order to compensate variations in volume during the intercalation and de-intercalation of lithium ions in the electrodes during the operation. Aluminum and graphite have proved to be suitable for use as metals that are stable in the electrochemical environment of the battery for the system used commonly with lithium cobalt oxide as the cathode material and graphite on the anode side. However, the process being described here is not limited to these metals.
The manufacture of expanded metals shall be briefly explained below. The process is schematically shown in Figure 1. Metal foils (1) of a suitable thickness are provided with a punched pattern in a punching tool (2) and then stretched (3). The geometric data of the expanded metal, such as the width of the web, the opening diagonals and the percentage of open area are set by designing the punched pattern and the rate of stretching.
The advantages of the use of expanded metals as current collectors are obvious: Compared to foils, they have an open-pore structure, so that the weight of the current collectors can be reduced, which entails advantages in the gravimetric energy density. In addition, the expanded metal is elastic in such a way that it can follow the changes in volume during the intercalation and de-intercalation of lithium in the electrodes, without delamination taking place. Delamination would in turn reduce the cycle life of the batteries.
Another advantage is achieved in terms of production engineering when expanded metal is used in lithium-polymer batteries. This type of battery is usually manufactured as follows: The electrodes are either deposited directly on metal foils (see US 6,306,215) or are laminated on the current collector by lamination under pressure and optionally under the action of temperature (DE 199 52 335). A firm composite of the three different foils for the anode with the current collector, the separator and the cathode with the current collector is then prepared in a second step by lamination or by the winding technique. This composite is then impregnated with electrolyte liquid. The electrolyte liquid must be distributed uniformly in the complete foil composite. This is achieved essentially by capillary forces. This process is frequently also supported by the additional formation of pores, which are produced by adding a plasticizing agent to the electrode and separator materials, which is again removed by means of a solvent after the components have been laminated together. Closed metal foils make difficult the penetration of the liquid electrolyte into the battery body, i.e., they prolong the duration of the process. The use of an open-mesh expanded metal therefore offers considerable advantages in terms of process engineering.
To achieve good adhesion and low contact resistance at the interface between the metallic current collector and the laminated electrode, it proved to be advantageous to coat the current collector with a thin layer of adhesion promoter before it is connected to the electrode, and it is especially advantageous if the said adhesion promoter layer has an electron conductivity.
A number of proposals have been made in the state of the art concerning the technique to be used to apply such adhesion promoters and their suitable compositions. They comprise the coating of current collectors made of expanded metals or of other perforated collectors (nettings, grids) in liquids or pastes by spin coating, dipping or coating (see US 6,306,215 and US 5, 824,120), the application of a layer that contains carbon powder and an adhesiveness-improving polymer, by means of electrostatic forces (US 5,542,163), or a plasma polymerization method, by which a layer of an electrically conductive, polymeric, adhesion-improving material is applied to the current collector (see US 6,007,588). All the documents mentioned describe electrochemical cells from electrode materials with a plasticizing agent, which is again washed out of the cells after the individual components (electrode and separator layers or foils, current collector) have been laminated together in order to generate pore volume for the electrolyte liquid, as was described above. It is also possible to apply the coating by applying a suitable suspension by means of printing methods.
Corresponding suspensions are commercially available. Methods based on the use of printing rollers, for example, reverse roll coating, are used. The suspensions consist, as a rule, of a carbon/polymer mixture in a suitable solvent, such as water.
Considerable problems arise in practical application when coating solutions are applied according to methods used in the printing trade. The layer thickness of the suspensions applied are usually between approx. 1 pm and approx. 20 pm. Insufficient wetting is invariably observed in the printing roller process, which leads to nonuniform distribution of the suspension on the metal. As a result, the contact resistance increases or contact is even lost between the current collector and the electrode at the poorly coated sites during the operation of electrochemical components equipped with expanded metals coated in this manner, e.g., batteries, and this has disadvantageous consequences for the service life of the components. However, the use of thicker adhesion promoter layers is ruled out because of the undesired reduction of the energy density that is associated with this.
Moreover, problems arise in terms of the hardware when printing methods are used to apply the adhesion promoter layers. To guarantee the precise guiding of the foils during coating, guiding of the metal foil over several deflecting rollers is necessary. In addition, the foil must be kept under a certain mechanical tension during its run through the coating machine. While this does not cause any technical problem in case of the use of closed metal foils, for example, foils made of aluminum or copper in case of foil thicknesses as low as approx. 10 pm to 15 pm, expanded metals tend to tear even under low tensile stresses. This is especially critical in case of aluminum expanded metals. Typical thicknesses of expanded metals are 50 pm or even less. Massive yield problems arise due to tearing even on machines designed especially for coating expanded metals.
However, a changeover to thicker current collectors to improve the reliability of the process is just as impossible, because of an undesired reduction of the energy density, as coating with an excessively thick layer.
The object of the present invention is to provide a process for manufacturing coated expanded metals, which leads to improved yields and with which the top side and the underside of thin expanded metals can also be coated with a sufficiently thin layer of conductive adhesion promoters.
The said object is accomplished by a process in which a closed metal foil is first coated and this is then converted into expanded metal. This offers the advantage that the coating is applied to a mechanically substantially more stable metal foil, so that a product possessing the necessary properties can be manufactured with a high yield and the amount of rejects can be greatly reduced. Coating may be performed on one side or on both sides. It was quite surprising to find with this procedure that the coating applied to the foil does not flake off during stretching. This was not to be expected at all, because it was not possible to assume that it would be sufficiently elastic and, moreover, possess such a good adhesion that the deformation of the metal lying under the coating does not lead to separation of the coating.
It was equally fully surprising that another advantage of the present invention was able to be observed, namely, that the service life of the punching knives increases during the manufacture of the expanded metal. This could be due to the fact that usual adhesion promoters are suspensions containing graphite, which act as lubricants for the knives during the punching operation and thus contribute to the prolongation of their service life.
According to one aspect of the invention there is provided a process for manufacturing an expanded metal with a coating, wherein the coating is applied to a closed metal foil and the closed metal foil is converted into expanded metal by punching holes or slits into the metal foil and then stretching same only after applying the coating, wherein the coating contains at least one material which is silver, graphite, another carbon material, or any combination thereof, together with a binder that improves adhesiveness, an organic or inorganic polymer, which is graphitized after being applied to the metal, and an electrically conducting organic polymer.
According to a further aspect of the invention there is provided an expanded metal provided with a coating, wherein the expanded metal is manufactured according to a process as described herein.
According to another aspect of the invention there is provided use of an expanded metal as described herein as a current collector in or for an anode foil or in or for a cathode foil.
However, a changeover to thicker current collectors to improve the reliability of the process is just as impossible, because of an undesired reduction of the energy density, as coating with an excessively thick layer.
The object of the present invention is to provide a process for manufacturing coated expanded metals, which leads to improved yields and with which the top side and the underside of thin expanded metals can also be coated with a sufficiently thin layer of conductive adhesion promoters.
The said object is accomplished by a process in which a closed metal foil is first coated and this is then converted into expanded metal. This offers the advantage that the coating is applied to a mechanically substantially more stable metal foil, so that a product possessing the necessary properties can be manufactured with a high yield and the amount of rejects can be greatly reduced. Coating may be performed on one side or on both sides. It was quite surprising to find with this procedure that the coating applied to the foil does not flake off during stretching. This was not to be expected at all, because it was not possible to assume that it would be sufficiently elastic and, moreover, possess such a good adhesion that the deformation of the metal lying under the coating does not lead to separation of the coating.
It was equally fully surprising that another advantage of the present invention was able to be observed, namely, that the service life of the punching knives increases during the manufacture of the expanded metal. This could be due to the fact that usual adhesion promoters are suspensions containing graphite, which act as lubricants for the knives during the punching operation and thus contribute to the prolongation of their service life.
According to one aspect of the invention there is provided a process for manufacturing an expanded metal with a coating, wherein the coating is applied to a closed metal foil and the closed metal foil is converted into expanded metal by punching holes or slits into the metal foil and then stretching same only after applying the coating, wherein the coating contains at least one material which is silver, graphite, another carbon material, or any combination thereof, together with a binder that improves adhesiveness, an organic or inorganic polymer, which is graphitized after being applied to the metal, and an electrically conducting organic polymer.
According to a further aspect of the invention there is provided an expanded metal provided with a coating, wherein the expanded metal is manufactured according to a process as described herein.
According to another aspect of the invention there is provided use of an expanded metal as described herein as a current collector in or for an anode foil or in or for a cathode foil.
According to yet another aspect of the invention there is provided a use of an expanded metal as described herein in an electrochemical cell.
The present invention is explained in the attached drawings, in which Figure 1 shows the sequence of a laminate suitable for use for a battery, Figure 2 shows the top view of such a laminate, Figure 3 shows a schematic view of the manufacture of the expanded metal, Figure 4 shows a diagram showing the relative capacity of a battery provided with an expanded metal manufactured according to the present invention as a collector, and Figure 5 shows the relative capacity of a battery with an expanded metal manufactured according to the present invention as a collector compared to the capacity of a battery with a collector manufactured in the usual manner.
It is especially favorable if the metal foil is subjected to a corona discharge surface treatment already before the coating operation, because this measure leads to a further improvement in the adhesion of the coating on the expanded metal.
3a It is frequently preferred to stretch the metal during the expansion at most only to the extent that the short diagonal will have a length of about 1 mm and the long diagonal will have a length of about 2 mm because, depending on the flexibility of the coating materials used, the coating may separate in some cases when a greater stretching is carried out.
All the materials with which the desired properties that the expanded metal needs for its later use can be obtained are suitable for coating the metal foils that will subsequently be subjected to the expansion process. These are above all good adhesion to the electrodes as well as good electric conductivity in the case of expanded metals used as current collectors.
However, it should be clear that the process according to the present invention is not limited to the manufacture of coated expanded metals for current collectors. It can rather be used wherever thin expanded metals with sensitive, thin coatings are to be used and it is not necessary that the openings generated during the punching and stretching also be coated laterally.
For example, materials such as graphite or other suitable carbon materials as well as adhesion-improving organic polymers shall be mentioned as suitable materials for coatings with good adhesion and good electric conductivity. The carbon materials may be applied in a binder, e.g., an organic polymer suspension, which binder can subsequently be dried, (after)cured or subjected to an additional polymerization on the surface. One example is EB-012 from the firm of Acheson, U.S.A., a graphite suspension, which contains a thermoplastic binder.
Other examples are suspensions containing silver instead of graphite. The binders may be, e.g., epoxy resins, thermoplastics, duromers, vinyl resins, cellulose or fluoroelastomers.
However, it is also possible to use other suitable materials instead of graphite suspensions if they impart the said properties, for example, electrically conductive organic polymers such as polyvinylpyrrolidone.
Furthermore, polymer suspensions that are graphitized after the application to the metal are well suited for use as a coating.
The process according to the present invention was found in light of the poor quality of expanded metals coated according to the printing method. However, it is not limited to specific coating techniques. Instead of application according to the printing method, it is also possible to use, e.g., spin coating, roller coating, application with a doctor blade, dip coating, electrostatic application (powder coating) or the plasma method, as they are known, among other things, from the above-mentioned state of the art.
The expanded metals manufactured according to the present invention differ from the conventional ones by the fact that their openings, produced during the punching and stretching, are not coated laterally. However, this is of no disadvantage for their use as current collectors.
The expanded metals that are or can be manufactured according to the present invention are especially suitable, among other things, for use in electrochemical cells during the manufacture of which the addition of a plasticizer, which would have to be removed again in a subsequent washing process, to the electrode materials and/or the separator to produce a porosity necessary for taking up the liquid electrolyte is avoided, because this manufacturing process, which is described in the US patent specifications 5,456,000 and 6,063,519, requires, as an additional requirement on the adhesion promoter layer, that this layer be chemically stable in respect to the wash liquid. Partial separation of the electrode foils from the current collector may easily occur during the washing out of the plasticizer, which has unfavorable consequences for the cycle life and the impedance of a battery. It is therefore proposed according to the present invention as an especially favorable solution that electrochemical components be manufactured with the current collectors manufactured according to the present invention, whose electrodes and separator were manufactured without a plasticizer that has to be washed out.
The present invention shall be explained in greater detail below on the basis of examples.
Example 1 Copper Expanded Metal A copper foil with a thickness of 50 pm was coated on both sides with a commercially available suspension EB012 from Acheson Colloids B.V. (a thixotropic graphite suspension in a thermoplastic binder). To set the optimal viscosity for the application, the solids content in the suspension was reduced from 30% to 20% by adding water.
Coating was carried out on one side by means of a simple laminating roller first on the front side and, in a second run, on the reverse side. The copper foil was a commercially available standard foil for use in batteries. The wet layer thickness applied was approx. 20 pm at a feed rate of 2.5 m/minute. Drying was carried out at approx. 80 C. The layer thickness of the adhesion promoter layer was still 4 pm after drying. The foil thus coated was subsequently subjected to further processing into expanded metal. Stretching was set such that the short diagonal had a length of 1 mm and the long diagonal had a length of 2 mm.
The material obtained was free from separations and cracks in the metal and was able to be subjected to further use at a rate of 100%.
Comparison Example 1 Example I was repeated, and stretching was set such that the short diagonal had a length of 1.5 mm and the long diagonal had a length of 3 mm. There were cracks in the product;
it was flaked off in some areas. The reject was about 30% of the area.
Comparison Example la Example I was repeated such that the copper foil was first converted into expanded metal and this was coated as described. A large number of cracked areas and areas with flaked-off coating were found on the material obtained in a non-uniform distribution.
Only one of 6 batches (rolls) was suitable for use in such a way that it was able to be used for the further processing of the expanded metal into current collectors. On the whole, more than 50% of the area of the expanded metal was damaged.
Example 2 Aluminum Expanded Metal An aluminum foil with a thickness of 50 pm was coated on both sides with the above-mentioned, commercially available suspension EB012 from Acheson Colloids B.V.
To set the optimal viscosity for the application, the solids content in the suspension was reduced from 30% to 20% by adding water. Coating was carried out by means of a simple laminating roller on one side, first on the front side and, in a second run, on the reverse side. The copper foil was a commercially available standard foil for use in batteries. The wet layer thickness applied was approx. 20 pm at a feed rate of 2 m/minute.
Drying was carried out at approx. 80 C. The layer thickness of the adhesion promoter layer was still 4 pm after drying. The foil thus coated was subsequently subjected to further processing into expanded metal. Stretching was set such that the short diagonal had a length of 1 mm and the long diagonal had a length of 2 mm. The material obtained showed no separations and cracks in the metal and was able to be used further at a rate of 100%.
Comparison Example 2 Example 2 was repeated, and stretching was set such that the short diagonal had a length of 1.5 nun and the long diagonal had a length of 3 mm. The product had cracks in the coating; it was flaked off in some areas. The reject was about 25% of the area.
Example 3 Anode Foil To prepare an anode foil, 1.7 g of spheroidal graphite MCMB were mixed with 0.
1 g of conductive carbon black (acetylene black), 0.2 g of polyvinylidene fluoride, copolymer (PVDF-HFP) and 2 g of acetone and processed into a uniformly dispersed paste in a cutting mixer. This paste was subsequently applied to a glass plate to form a foil with a doctor plate. A self-supporting foil, which was removed from the glass plate, was left behind after the evaporation of the solvent. The layer thickness of the dried layer was approx. 100 pm.
Example 4 Cathode Foil Corresponding to the anode foil, a cathode foil of equal size was prepared with the following composition: 3.6 g of LiCoO2 were mixed with 0.2 g of conductive carbon black (acetylene black) and 0.2 g of PVDF as well as 4 g of acetone. Its layer thickness was likewise approx. 100 pm.
Example 5 Separator Foil 1.5 g of a ceramic filler (lithium aluminum titanium phosphate) Lil.3Alo.3Til.7(PO4)3 was processed with 0.5 g of PVDF-HFP and 2.4 g of acetone as described in (3) to prepare a separator foil with a thickness of about 50 pm.
Example 6 Lamination The electrode foils were laminated onto the particular collector grids in a roll type laminator. The foils were preheated to 160 C and then laminated under the roller with a pressing force of 236 kp. The feed rate was 40 nun/sec. Subsequent tape tests showed good adhesion of the particular foils to the corresponding collector grids.
The three elements, namely, the anode with the copper collector grid, the cathode with the aluminum collector grid and the separator foil, were laminated together in a second lamination step.
The force was 16 kp, likewise at a lamination temperature of 160 C and a feed rate of 20 mm/sec. The design of the battery body is shown in Figures 1 and 2. Figure 1 shows a cross section through a battery body, while Figure 2 shows the top view of a battery body.
Figure 1 shows the aluminum expanded metal (4) coated with adhesion promoter with the cathode foil (5) laminated to it and with the separator foil (6). The counterelectrode consists of copper expanded metal (8) coated with adhesion promoter with the anode foil (7) laminated to it. The aluminum expanded metal is seen in the top view in Figure 4.
Two contact tongues (9) for contacting the body after packaging in foil are led out to the side.
Example 7 Manufacture of the Battery The battery was introduced into a plastic-coated aluminum foil such that electric contacts were able to be led to the outside from the current collectors. A commercially available conducting salt solution LP30 was subsequently introduced into the laminated foil composite by absorption in a water-free protective gas atmosphere. The bag was then sealed hermetically. The battery was then formed and subsequently measured electrically.
A good cycle life was found under a load with C rate. The curve is shown in Figure 4.
More than 80% of the initial capacity was still present after 300 charge/discharge cycles.
The relative capacity of the battery was compared to that of a battery whose collector consisted of (error-free) coated expanded metal manufactured in the conventional manner.
As is apparent from Figure 5, the performance data of the two batteries are essentially identical. The process according to the present invention consequently leads to coatings of the same quality as in the case of expanded metals coated in the usual manner.
The present invention is explained in the attached drawings, in which Figure 1 shows the sequence of a laminate suitable for use for a battery, Figure 2 shows the top view of such a laminate, Figure 3 shows a schematic view of the manufacture of the expanded metal, Figure 4 shows a diagram showing the relative capacity of a battery provided with an expanded metal manufactured according to the present invention as a collector, and Figure 5 shows the relative capacity of a battery with an expanded metal manufactured according to the present invention as a collector compared to the capacity of a battery with a collector manufactured in the usual manner.
It is especially favorable if the metal foil is subjected to a corona discharge surface treatment already before the coating operation, because this measure leads to a further improvement in the adhesion of the coating on the expanded metal.
3a It is frequently preferred to stretch the metal during the expansion at most only to the extent that the short diagonal will have a length of about 1 mm and the long diagonal will have a length of about 2 mm because, depending on the flexibility of the coating materials used, the coating may separate in some cases when a greater stretching is carried out.
All the materials with which the desired properties that the expanded metal needs for its later use can be obtained are suitable for coating the metal foils that will subsequently be subjected to the expansion process. These are above all good adhesion to the electrodes as well as good electric conductivity in the case of expanded metals used as current collectors.
However, it should be clear that the process according to the present invention is not limited to the manufacture of coated expanded metals for current collectors. It can rather be used wherever thin expanded metals with sensitive, thin coatings are to be used and it is not necessary that the openings generated during the punching and stretching also be coated laterally.
For example, materials such as graphite or other suitable carbon materials as well as adhesion-improving organic polymers shall be mentioned as suitable materials for coatings with good adhesion and good electric conductivity. The carbon materials may be applied in a binder, e.g., an organic polymer suspension, which binder can subsequently be dried, (after)cured or subjected to an additional polymerization on the surface. One example is EB-012 from the firm of Acheson, U.S.A., a graphite suspension, which contains a thermoplastic binder.
Other examples are suspensions containing silver instead of graphite. The binders may be, e.g., epoxy resins, thermoplastics, duromers, vinyl resins, cellulose or fluoroelastomers.
However, it is also possible to use other suitable materials instead of graphite suspensions if they impart the said properties, for example, electrically conductive organic polymers such as polyvinylpyrrolidone.
Furthermore, polymer suspensions that are graphitized after the application to the metal are well suited for use as a coating.
The process according to the present invention was found in light of the poor quality of expanded metals coated according to the printing method. However, it is not limited to specific coating techniques. Instead of application according to the printing method, it is also possible to use, e.g., spin coating, roller coating, application with a doctor blade, dip coating, electrostatic application (powder coating) or the plasma method, as they are known, among other things, from the above-mentioned state of the art.
The expanded metals manufactured according to the present invention differ from the conventional ones by the fact that their openings, produced during the punching and stretching, are not coated laterally. However, this is of no disadvantage for their use as current collectors.
The expanded metals that are or can be manufactured according to the present invention are especially suitable, among other things, for use in electrochemical cells during the manufacture of which the addition of a plasticizer, which would have to be removed again in a subsequent washing process, to the electrode materials and/or the separator to produce a porosity necessary for taking up the liquid electrolyte is avoided, because this manufacturing process, which is described in the US patent specifications 5,456,000 and 6,063,519, requires, as an additional requirement on the adhesion promoter layer, that this layer be chemically stable in respect to the wash liquid. Partial separation of the electrode foils from the current collector may easily occur during the washing out of the plasticizer, which has unfavorable consequences for the cycle life and the impedance of a battery. It is therefore proposed according to the present invention as an especially favorable solution that electrochemical components be manufactured with the current collectors manufactured according to the present invention, whose electrodes and separator were manufactured without a plasticizer that has to be washed out.
The present invention shall be explained in greater detail below on the basis of examples.
Example 1 Copper Expanded Metal A copper foil with a thickness of 50 pm was coated on both sides with a commercially available suspension EB012 from Acheson Colloids B.V. (a thixotropic graphite suspension in a thermoplastic binder). To set the optimal viscosity for the application, the solids content in the suspension was reduced from 30% to 20% by adding water.
Coating was carried out on one side by means of a simple laminating roller first on the front side and, in a second run, on the reverse side. The copper foil was a commercially available standard foil for use in batteries. The wet layer thickness applied was approx. 20 pm at a feed rate of 2.5 m/minute. Drying was carried out at approx. 80 C. The layer thickness of the adhesion promoter layer was still 4 pm after drying. The foil thus coated was subsequently subjected to further processing into expanded metal. Stretching was set such that the short diagonal had a length of 1 mm and the long diagonal had a length of 2 mm.
The material obtained was free from separations and cracks in the metal and was able to be subjected to further use at a rate of 100%.
Comparison Example 1 Example I was repeated, and stretching was set such that the short diagonal had a length of 1.5 mm and the long diagonal had a length of 3 mm. There were cracks in the product;
it was flaked off in some areas. The reject was about 30% of the area.
Comparison Example la Example I was repeated such that the copper foil was first converted into expanded metal and this was coated as described. A large number of cracked areas and areas with flaked-off coating were found on the material obtained in a non-uniform distribution.
Only one of 6 batches (rolls) was suitable for use in such a way that it was able to be used for the further processing of the expanded metal into current collectors. On the whole, more than 50% of the area of the expanded metal was damaged.
Example 2 Aluminum Expanded Metal An aluminum foil with a thickness of 50 pm was coated on both sides with the above-mentioned, commercially available suspension EB012 from Acheson Colloids B.V.
To set the optimal viscosity for the application, the solids content in the suspension was reduced from 30% to 20% by adding water. Coating was carried out by means of a simple laminating roller on one side, first on the front side and, in a second run, on the reverse side. The copper foil was a commercially available standard foil for use in batteries. The wet layer thickness applied was approx. 20 pm at a feed rate of 2 m/minute.
Drying was carried out at approx. 80 C. The layer thickness of the adhesion promoter layer was still 4 pm after drying. The foil thus coated was subsequently subjected to further processing into expanded metal. Stretching was set such that the short diagonal had a length of 1 mm and the long diagonal had a length of 2 mm. The material obtained showed no separations and cracks in the metal and was able to be used further at a rate of 100%.
Comparison Example 2 Example 2 was repeated, and stretching was set such that the short diagonal had a length of 1.5 nun and the long diagonal had a length of 3 mm. The product had cracks in the coating; it was flaked off in some areas. The reject was about 25% of the area.
Example 3 Anode Foil To prepare an anode foil, 1.7 g of spheroidal graphite MCMB were mixed with 0.
1 g of conductive carbon black (acetylene black), 0.2 g of polyvinylidene fluoride, copolymer (PVDF-HFP) and 2 g of acetone and processed into a uniformly dispersed paste in a cutting mixer. This paste was subsequently applied to a glass plate to form a foil with a doctor plate. A self-supporting foil, which was removed from the glass plate, was left behind after the evaporation of the solvent. The layer thickness of the dried layer was approx. 100 pm.
Example 4 Cathode Foil Corresponding to the anode foil, a cathode foil of equal size was prepared with the following composition: 3.6 g of LiCoO2 were mixed with 0.2 g of conductive carbon black (acetylene black) and 0.2 g of PVDF as well as 4 g of acetone. Its layer thickness was likewise approx. 100 pm.
Example 5 Separator Foil 1.5 g of a ceramic filler (lithium aluminum titanium phosphate) Lil.3Alo.3Til.7(PO4)3 was processed with 0.5 g of PVDF-HFP and 2.4 g of acetone as described in (3) to prepare a separator foil with a thickness of about 50 pm.
Example 6 Lamination The electrode foils were laminated onto the particular collector grids in a roll type laminator. The foils were preheated to 160 C and then laminated under the roller with a pressing force of 236 kp. The feed rate was 40 nun/sec. Subsequent tape tests showed good adhesion of the particular foils to the corresponding collector grids.
The three elements, namely, the anode with the copper collector grid, the cathode with the aluminum collector grid and the separator foil, were laminated together in a second lamination step.
The force was 16 kp, likewise at a lamination temperature of 160 C and a feed rate of 20 mm/sec. The design of the battery body is shown in Figures 1 and 2. Figure 1 shows a cross section through a battery body, while Figure 2 shows the top view of a battery body.
Figure 1 shows the aluminum expanded metal (4) coated with adhesion promoter with the cathode foil (5) laminated to it and with the separator foil (6). The counterelectrode consists of copper expanded metal (8) coated with adhesion promoter with the anode foil (7) laminated to it. The aluminum expanded metal is seen in the top view in Figure 4.
Two contact tongues (9) for contacting the body after packaging in foil are led out to the side.
Example 7 Manufacture of the Battery The battery was introduced into a plastic-coated aluminum foil such that electric contacts were able to be led to the outside from the current collectors. A commercially available conducting salt solution LP30 was subsequently introduced into the laminated foil composite by absorption in a water-free protective gas atmosphere. The bag was then sealed hermetically. The battery was then formed and subsequently measured electrically.
A good cycle life was found under a load with C rate. The curve is shown in Figure 4.
More than 80% of the initial capacity was still present after 300 charge/discharge cycles.
The relative capacity of the battery was compared to that of a battery whose collector consisted of (error-free) coated expanded metal manufactured in the conventional manner.
As is apparent from Figure 5, the performance data of the two batteries are essentially identical. The process according to the present invention consequently leads to coatings of the same quality as in the case of expanded metals coated in the usual manner.
Claims (15)
1. A process for manufacturing an expanded metal with a coating, wherein the coating is applied to a closed metal foil and the closed metal foil is converted into expanded metal by punching holes or slits into the metal foil and then stretching same only after applying the coating, wherein the coating contains at least one material which is silver, graphite, another carbon material, or any combination thereof, together with a binder that improves adhesiveness, an organic or inorganic polymer, which is graphitized after being applied to the metal, and an electrically conducting organic polymer.
2. A process in accordance with claim 1, wherein the coating improves the adhesiveness of the expanded metal to an electrode material and/or the electron conductivity on the surface of the expanded metal.
3. A process in accordance with claim 1 or 2, wherein the metal is copper or aluminum.
4. A process in accordance with any one of claims 1 to 3, wherein the metal foil is subjected to a corona discharge surface treatment before it is coated.
5. A process in accordance with any of claims 1 to 4, wherein when the metal foil is converted into expanded metal, the stretching is performed in such a way that the pores resulting from stretching the holes or slits have a short diagonal with a length of up to I
mm and a long diagonal with a length of up to 2 mm.
mm and a long diagonal with a length of up to 2 mm.
6. A process in accordance with any one of claims 1 to 5, wherein the coating is applied by means of a printing technique, spin coating, rolling, application with a doctor blade, dip coating, electrostatic powder coating or by means of a plasma process.
7. An expanded metal provided with a coating, wherein the expanded metal is manufactured according to a process as defined in any one of claims 1 to 6.
8. An expanded metal provided with a coating in accordance with claim 7, wherein the coating improves the adhesiveness of the expanded metal to an electrode material and/or the electron conductivity on the surface of the expanded metal.
9. An expanded metal provided with a coating produced by a process as defined in claim 1, wherein the coating was applied by means of a suspension containing graphite or another carbon material and a binder, or of an organic or inorganic-organic polymer, which was subsequently graphitized.
10. Use of an expanded metal as defined in claim 8 or 9 as a current collector in or for an anode foil or in or for a cathode foil.
11. A use in accordance with claim 10, wherein the current collector and the anode foil as well as the cathode foil are laminated together.
12. A use in accordance with one of the claims 10 or 11, wherein the anode foil and the cathode foil were prepared without the use of plasticizing agent.
13. A use of expanded metal in accordance with claim 8 or 9 in an electrochemical cell.
14. A use in accordance with claim 13, wherein the electrochemical cell is a battery.
15. A use in accordance with claim 13 or 14, wherein the battery is a lithium battery.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10257186.4 | 2002-12-06 | ||
DE10257186A DE10257186A1 (en) | 2002-12-06 | 2002-12-06 | Process for the production of coated expanded metals and the use of such metals as current conductors in electrical engineering components |
PCT/EP2003/012596 WO2004053200A1 (en) | 2002-12-06 | 2003-11-11 | Method for producing drawn coated metals and use of said metals in the form of a current differentiator for electrochemical components |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2507399A1 CA2507399A1 (en) | 2004-06-24 |
CA2507399C true CA2507399C (en) | 2012-07-03 |
Family
ID=32477449
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA2507399A Expired - Lifetime CA2507399C (en) | 2002-12-06 | 2003-11-11 | Method for producing drawn coated metals and use of said metals in the form of a current differentiator for electrochemical components |
Country Status (10)
Country | Link |
---|---|
US (1) | US20060137168A1 (en) |
EP (1) | EP1570113B1 (en) |
JP (1) | JP4996053B2 (en) |
KR (1) | KR101084883B1 (en) |
AT (1) | ATE340279T1 (en) |
AU (1) | AU2003283389A1 (en) |
CA (1) | CA2507399C (en) |
DE (2) | DE10257186A1 (en) |
TW (1) | TWI329375B (en) |
WO (1) | WO2004053200A1 (en) |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004020899B3 (en) * | 2004-04-28 | 2005-12-01 | Saint-Gobain Performance Plastics Pampus Gmbh | A method for producing a sliding bearing material having a mesh-like structure, a sliding bearing material produced thereafter, and a use thereof |
KR100866323B1 (en) * | 2007-02-05 | 2008-10-31 | 한국기계연구원 | Thin Film Coating Method and Apparatus for Large Area |
DE102008043625A1 (en) * | 2008-11-10 | 2010-05-20 | Dilo Trading Ag | Lithium-ion-cell comprises electrode arrester film having cutting-edges of predetermined sizes, where modified separator and electrolyte are also included |
DE102009049693A1 (en) | 2009-10-16 | 2011-04-21 | Süd-Chemie AG | Pure phase lithium aluminum titanium phosphate and process for its preparation and use |
DE102009049694A1 (en) | 2009-10-16 | 2011-04-28 | Süd-Chemie AG | Pure phase lithium aluminum titanium phosphate and process for its preparation and use |
DE102012109032B4 (en) | 2012-09-25 | 2019-11-28 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Method for filling electrochemical cells |
DE102012112186A1 (en) | 2012-12-12 | 2014-06-26 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Composite material, process for its production, system made therefrom and use thereof |
JP2019503865A (en) * | 2015-11-24 | 2019-02-14 | スリーエム イノベイティブ プロパティズ カンパニー | Integral expanded metal mesh with rolled linear strands |
US10519667B1 (en) * | 2016-01-25 | 2019-12-31 | E-Z Products Llc | Color-coated gutter cover of expanded metal and method of manufacture |
DE102017126315A1 (en) * | 2017-11-09 | 2019-05-09 | GRAMMER Interior Components GmbH | Expanded metal with meshes of different mesh shape |
BR112021020579A2 (en) * | 2019-04-17 | 2021-12-07 | 2555663 Ontario Ltd | Lithium metal anode assembly, lithium-based battery and method and apparatus for manufacturing the same |
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DE2449407A1 (en) * | 1974-10-17 | 1976-04-22 | Hans Hillesheim | Sheet metal corrosion protective cladding - has anchorage of range of rubber or plastic layers assisted by adhesive,chemicals, and mechanical deforming |
FR2431195A1 (en) * | 1978-07-11 | 1980-02-08 | Sersen Ste Civile | ELECTRICAL BATTERIES, ACCUMULATORS AND GENERATORS WITH NON-METALLIC ELECTRODES OR IN SOLUTION |
US5451307A (en) * | 1985-05-07 | 1995-09-19 | Eltech Systems Corporation | Expanded metal mesh and anode structure |
GB8903321D0 (en) * | 1989-02-14 | 1989-04-05 | Ici Plc | Metal mesh and production thereof |
IT1248564B (en) * | 1991-06-27 | 1995-01-19 | Permelec Spa Nora | ELECTROCHEMICAL DECOMPOSITION OF NEUTRAL SALTS WITHOUT HALOGEN OR ACID CO-PRODUCTION AND ELECTROLYSIS CELL SUITABLE FOR ITS REALIZATION. |
JP3042150B2 (en) * | 1992-03-25 | 2000-05-15 | 松下電器産業株式会社 | Manufacturing method of grid for lead-acid battery |
US5464707A (en) * | 1992-10-29 | 1995-11-07 | Moulton; Russell D. | Electrically-conducting adhesion-promoters |
US5542163A (en) * | 1993-04-19 | 1996-08-06 | Chang; On K. | Electrically-conducting adhesion-promoter |
JPH07135023A (en) * | 1993-11-11 | 1995-05-23 | Sony Corp | Manufacture of battery |
DE19633463A1 (en) * | 1995-09-02 | 1997-03-06 | Basf Magnetics Gmbh | Simple reliable prodn. of reversible lithium electrodes for electrochemical cell, esp. lithium battery |
US5824120A (en) * | 1996-04-10 | 1998-10-20 | Valence Technology, Inc. | Electrically conductive adhesion promoters for current collectors |
US6007588A (en) * | 1998-02-17 | 1999-12-28 | Valence Technology, Inc. | Methods for coating current collector with polymeric adhesives |
US6306215B1 (en) * | 1998-03-10 | 2001-10-23 | Valence Technology, Inc. | Apparatus for coating current collectors |
JP2001357854A (en) * | 2000-06-13 | 2001-12-26 | Matsushita Electric Ind Co Ltd | Nonaqueous secondary battery |
DE10029831C1 (en) * | 2000-06-16 | 2002-02-28 | Siemens Ag | Method and device for operating a linear lambda probe |
US6465121B1 (en) * | 2000-08-30 | 2002-10-15 | Lev M. Dawson | Method for distributing electrolyte in batteries |
JP4020296B2 (en) * | 2000-12-21 | 2007-12-12 | キヤノン株式会社 | Ionic conduction structure, secondary battery and method for producing them |
US20060159999A1 (en) * | 2001-07-23 | 2006-07-20 | Kejha Joseph B | Method of automated prismatic electrochemical cells production and method of the cell assembly and construction |
-
2002
- 2002-12-06 DE DE10257186A patent/DE10257186A1/en not_active Withdrawn
-
2003
- 2003-10-03 TW TW092127410A patent/TWI329375B/en not_active IP Right Cessation
- 2003-11-11 WO PCT/EP2003/012596 patent/WO2004053200A1/en active IP Right Grant
- 2003-11-11 KR KR1020057010238A patent/KR101084883B1/en active IP Right Grant
- 2003-11-11 US US10/537,930 patent/US20060137168A1/en not_active Abandoned
- 2003-11-11 EP EP03775342A patent/EP1570113B1/en not_active Expired - Lifetime
- 2003-11-11 AU AU2003283389A patent/AU2003283389A1/en not_active Abandoned
- 2003-11-11 JP JP2004557898A patent/JP4996053B2/en not_active Expired - Lifetime
- 2003-11-11 AT AT03775342T patent/ATE340279T1/en active
- 2003-11-11 CA CA2507399A patent/CA2507399C/en not_active Expired - Lifetime
- 2003-11-11 DE DE50305143T patent/DE50305143D1/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
EP1570113B1 (en) | 2006-09-20 |
EP1570113A1 (en) | 2005-09-07 |
DE10257186A1 (en) | 2004-07-15 |
US20060137168A1 (en) | 2006-06-29 |
DE50305143D1 (en) | 2006-11-02 |
KR101084883B1 (en) | 2011-11-17 |
KR20050093769A (en) | 2005-09-23 |
ATE340279T1 (en) | 2006-10-15 |
JP2006509334A (en) | 2006-03-16 |
JP4996053B2 (en) | 2012-08-08 |
CA2507399A1 (en) | 2004-06-24 |
TWI329375B (en) | 2010-08-21 |
WO2004053200A1 (en) | 2004-06-24 |
TW200414581A (en) | 2004-08-01 |
AU2003283389A1 (en) | 2004-06-30 |
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