Layer arrangement for coating a tool surface for the production of thin metal foils made of active material for battery anodes and tool with such a layer arrangement for the production of such metal foils as well as method for the production of thin metal foils

Abstract

The invention relates to a layer arrangement (1, 3) for coating a tool surface (2) for producing thin metal foils made of active material for at least one anode of a battery, characterized in that, for the dry production of the metal foils, an outer layer (1) that has a non-adherent effect towards the active material and at least one intermediate layer (3) located between the outer layer (1) and the tool surface (2) to increase the adhesion between the outer layer (1) and the tool surface (2) are provided. The invention further relates to a tool (6) with such a layer arrangement for producing such metal foils. The invention further relates to a method for producing such metal foils with such a tool (6). The invention also relates to a thin metal foil made of active material for anodes of a battery produced with such a tool (6) and / or with such a method.

Description

[0001] The invention relates to a layer arrangement for coating a tool surface for producing thin metal foils made of active material for battery anodes. The invention further relates to a tool with such a layer arrangement for producing such metal foils. The invention further relates to a method for producing such metal foils using such a tool. The invention also relates to a thin metal foil made of active material for battery anodes produced using such a tool and / or using such a method.

[0002] US 3,721,113 A discloses a method for reducing the thickness of lithium metal, in which the lithium metal is cold-rolled under pressure between substantially smooth surfaces of a solid polymer composition. Further processing methods for lithium sheets or laminates are known from US 2005 / 0 061 047 A1 and US 5,528,920 A.

[0003] The invention is therefore based on the object of proposing a layer arrangement, a tool, a method and a metal foil of the aforementioned type, which avoid adhesion to the tool surface and / or a reaction between the foil material and the tool surface during production and enable reliable dry production of thin metal foils made of active material with a high degree of purity for anodes of a battery.

[0004] The problem is solved by the features of claim 1 and alternatively by the features of claim 3 or 5. Further advantageous and claimed embodiments emerge from the respective subclaims, the description, and the drawing.

[0005] Thus, a layer arrangement for coating a tool surface for the production of thin metal foils made of active material for battery anodes is proposed. To prevent adhesion to the tool surface during production and enable reliable dry production of the metal foils, an outer layer for anti-adhesion is provided between the tool surface and the active material, and at least one intermediate layer is provided between the outer layer and the tool surface to increase adhesion between the outer layer and the tool surface.

[0006] As a result, the outer layer prevents the foil material from adhering to the tool surface during production, while the intermediate layer ensures reliable adhesion of the outer layer to the tool surface. Furthermore, a reaction between the foil material and the tool surface is reliably avoided. This enables the dry production of metal foils from active material without the use of additional lubricants, slip agents, or release agents.

[0007] In this way, contamination of the foil material during production due to contamination with lubricant, slip, or release agent residues, especially from the plastic release foils used, and especially silicon and dirt particles from the environment, can be avoided. This improves the purity of the produced metal foils made of active material and reliably prevents impairments in battery operation due to contamination of the foil material.

[0008] The intermediate layer can be metallic, preferably made of zirconium, titanium, vanadium, molybdenum, tungsten, or chromium. It can also be formed with a nitride of these metals. Alternatively, the intermediate layer can be constructed from a compound of at least two of the aforementioned materials. It is also possible to form the intermediate layer in multiple layers from the aforementioned materials.

[0009] The anti-adhesive outer layer has a low chemical affinity or reactivity with the film or active material. It is preferably carbon-based, for example, a DLC (diamond-like carbon) coating or a diamond coating.

[0010] Alternatively, the outer layer may preferably be formed from a coating containing boride or diboride.

[0011] In a further alternative, the outer layer can be ceramic, in particular made of nitride, oxide, oxynitride, carbon nitride or carbide or carbonitride.

[0012] A non-stick coating made of polymer is also conceivable.

[0013] Another alternative provides for the outer layer to be constructed from a combination of at least two of the aforementioned materials. The outer layer can also be formed from multiple layers of the aforementioned materials.

[0014] Additional lithium, sodium, magnesium or calcium repellent coatings may also be provided.

[0015] The object of the invention is also achieved by a tool with a layer arrangement as described above for the non-stick effect on the tool surface for the dry production of thin metal foils made of active material for battery anodes. This results in the advantages already described above.

[0016] The tool preferably has at least one roller or working drum, which serves for the dry thin rolling of the active material or an electrically conductive carrier material into a metal foil.

[0017] Alternatively or additionally, at least one roller or working drum is preferably provided, which serves for the dry lamination or dry plating of at least one metal foil made of active material on a metal foil made of electrically conductive carrier material to form a metal composite foil.

[0018] Alternatively or additionally, at least one roller or working drum, in particular a deflection roller, can be provided for dryly changing the direction of movement of the metal foil during production.

[0019] Preferably, each roller or working drum or deflection roller is provided on the tool surface with a layer arrangement as described above to provide an anti-adhesion effect between the tool surface and the active material. Support, carrier, or deflection rollers or drums coated with a layer arrangement as described above can also be provided.

[0020] Within the scope of a further aspect of the present invention, a method for producing thin metal foils from active material for battery anodes is presented using a tool as described above. Pure active material or an alloy of the active material, in particular an alloy of at least two different active materials, is dry-rolled into a thin metal foil. This results in the advantages already described above, in particular, contamination of the metal foils during production can be avoided.

[0021] Alternatively or additionally, an electrically conductive carrier material or an alloy thereof is preferably dry-rolled to form a metal foil.

[0022] In a further alternative or supplementary embodiment of the proposed method, at least one dry-thin rolled metal foil made of active material and one dry-thin rolled metal foil made of an electrically conductive carrier material are dry laminated or plated to form a metal composite foil.

[0023] Furthermore, a dry-rolled metal foil made of active material can be dry-laminated or plated on one or both sides of a dry-rolled metal foil made of the electrically conductive carrier material to form a metal composite foil.

[0024] The active material can alternatively consist of an alloy of the same, in particular an alloy of at least two different active materials. It can also be passivated, particularly for protection during transport.

[0025] The electrically conductive carrier material can also consist of an alloy, in particular of the aforementioned carrier materials.

[0026] In a further preferred embodiment of the invention, the active material used is lithium or sodium or magnesium or calcium or an alloy of the aforementioned active materials, in particular an alloy of at least two different aforementioned active materials, such as lithium and magnesium, or further alloys of the aforementioned materials, such as lithium and indium, lithium and boron, lithium and silicon, lithium and aluminum, lithium and tin or lithium and zinc, which is dry-rolled thin to form a metal foil.

[0027] In a further development of the proposed method, it is provided that copper or aluminum or nickel or steel or an alloy thereof is dry-rolled thinly to form a metal foil as the electrically conductive carrier material.

[0028] Preferably, in a further working step, a dry-thin rolled metal foil, preferably made of lithium or sodium or magnesium or calcium or an alloy of these active materials, and a dry-thin rolled metal foil, preferably made of copper or aluminum or nickel or steel, are dry laminated or plated to form a metal composite foil.

[0029] In this way, for example, a metal composite foil made of copper and lithium or of copper and an alloy of lithium and magnesium or of copper and an alloy of lithium and indium can be produced by dry lamination or plating.

[0030] The active materials can also be passivated, particularly for protection during transport.

[0031] Furthermore, the electrically conductive carrier material can consist of an alloy of the aforementioned carrier materials.

[0032] A metal foil made of active material for battery anodes can be produced using a tool described above and preferably by the method described above. The metal foil consists of dry-thin rolled lithium or sodium or magnesium or calcium.

[0033] Preferably, the metal foil consists of a dry-thin rolled alloy of the aforementioned active materials or of a dry-thin rolled alloy of at least two different aforementioned active materials.

[0034] Furthermore, a metal foil made of active material for anodes of a battery is proposed, which is produced using a tool as described above and preferably by the method as described above, wherein the metal foil as a metal composite foil consists in each case of a dry-thin-rolled lithium foil or sodium foil or magnesium foil or calcium foil, which is in each case dry-laminated or plated on one or both sides of a dry-thin-rolled copper foil or aluminum foil or nickel foil or steel foil as an electrically conductive carrier material. This results in the advantages already described above. In a particularly cost-effective embodiment of the invention, the electrically conductive carrier material can simultaneously serve as a current conductor.

[0035] In a particularly advantageous manner, the metal foils described above are free or at least largely free from contamination by lubricants, glidants or release agents.

[0036] Further features of the invention will become apparent from the following description and from the drawing, with the aid of which the present invention is further explained.

[0037] The figure shows schematically in a cross-section a greatly enlarged section of a layer arrangement according to the invention for coating a tool surface for producing thin metal foils made of active material for anodes of a battery.

[0038] The figure illustrates various embodiments of a layer arrangement according to the invention for coating a tool surface for producing thin metal foils made of active material for battery anodes. This illustration also illustrates the tool according to the invention, the method according to the invention, and the metal foils produced according to the invention.

[0039] The layer arrangement comprises an outer layer 1 for the non-adhesion effect between the active material (not shown) of the metal foil to be produced and the tool surface 2. The outer layer 1 also serves to prevent a reaction between the tool surface 2 and the active material. Furthermore, the layer arrangement comprises an intermediate layer 3 located between the outer layer 1 and the tool surface 2. The intermediate layer 3 serves to increase the adhesion between the outer layer 1 and the tool surface 2.

[0040] The outer layer thickness is preferably 0.5 µm to 10 µm. The intermediate layer preferably has a thickness of 0.02 µm to 1 µm.

[0041] The intermediate layer 3 is preferably made of metal, preferably zirconium, titanium, vanadium, molybdenum, tungsten, or chromium. Alternatively, it can also be formed with a nitride of these metals.

[0042] In a further alternative embodiment, the intermediate layer 3 can be constructed in multiple layers from the aforementioned materials or from a combination of at least two of them. An exemplary two-layer multilayer structure of the intermediate layer 3 is indicated by a dashed line 4. However, a multilayer structure of the intermediate layer 3 consisting of more than two layers is also conceivable.

[0043] The anti-adhesive outer layer 1 is applied on top of the intermediate layer 3. The outer layer 1 has a low chemical affinity or reactivity with the active material. The outer layer 1 is preferably carbon-based. It consists, for example, of a DLC (diamond-like carbon) coating or a diamond coating.

[0044] Alternatively, it may be designed as a boride or diboride-containing non-stick coating or as a ceramic non-stick coating, for example made of a nitride, oxide, oxynitride, carbide, or carbonitride, or as a polymer non-stick coating.

[0045] A further alternative provides for the outer layer 1 to be constructed in multiple layers from the aforementioned materials or from a combination of at least two of them. An exemplary two-layer multilayer structure of the outer layer 1 is indicated by a dashed line 5. However, a multilayer structure of the outer layer 1 consisting of more than two layers is also conceivable.

[0046] In this way, a simple layer arrangement that can be easily adapted to the application conditions is achieved as a non-stick coating with improved adhesion to a tool surface 2.

[0047] The proposed tool 6 for the dry production of thin metal foils made of active material for anodes of a battery is shown only with a section on the tool surface 2.

[0048] It comprises at least one roller or working drum or deflection roller 6, which is formed on the tool surface 2, thus preferably on the outer diameter or outer circumference of the roller or working drum or deflection roller 6 with a previously described layer arrangement 1, 3 as a non-stick coating.

[0049] In a preferred embodiment, at least one roller or working drum 6 is provided for dry thin rolling of the active material or an electrically conductive carrier material into a metal foil.

[0050] Preferably, at least one roller or working drum 6 is additionally provided, which serves for the dry lamination or dry plating of a metal foil made of active material on a metal foil made of electrically conductive carrier material to form a metal composite foil.

[0051] The rollers or working drums 6 are preferably made of steel or nitrided steel or carbonitrided steel.

[0052] Alternatively or additionally, one or more deflection rollers can be provided for dry changing of the direction of movement of the metal foil during production.

[0053] For the inventive production of a metal foil made of active material, dry thin-rolling, dry lamination, and dry roll plating can be used. During dry rolling, a foil made of active material is formed by pressure forming without the use of lubricants, glidants, or release agents by one or more rollers or working drums 6, so that the thickness of the foil made of active material is reduced. A dry-thin-rolled metal foil made of active material has a thickness that is preferably less than 100 µm. It can be dry hot-rolled or cold-rolled. For protection, particularly during transport, the active material used can also be passivated.

[0054] When using several rollers or working drums 6, the additional rollers or working drums 6 serve as support, carrying or deflection rollers or drums in order to avoid deformation of the rollers or working drums 6 which are in contact with the active material to be formed.

[0055] The thin metal foils can be produced by dry flat longitudinal rolling. All support, carrier, or deflection rollers or drums that come into contact with the active material to be formed are provided with a previously described layer arrangement 1, 3 as a non-stick coating on the tool surface 2.

[0056] Dry lamination can be performed on either one or two sides. Single-sided lamination uses two metal foils, one made of active material and one of an electrically conductive carrier material. In double-sided lamination, a metal foil made of active material is applied to both sides of the conductive carrier material. The foils are guided between two rollers or working drums 6 without the use of lubricants, slip agents, or release agents to bond the metal foils together to form a metal composite foil. The thickness of the metal foils does not change during this process. The primary bonding or adhesion mechanism is adhesion. In this way, a metal composite foil can be produced dry from multiple metal foils.

[0057] Dry roll cladding can be performed on either one or two sides. Single-sided cladding uses two metal foils, one made of active material and one of an electrically conductive carrier material. Double-sided cladding involves applying a metal foil made of active material to both sides of the conductive carrier material foil. The metal foils made of active material and conductive carrier material are guided under pressure between two rollers or working drums 6 without the use of lubricants, slip agents, or release agents to bond the metal foils together to form a metal composite foil. The pressure application changes the thickness of one or more metal foils, resulting in a material bond between the different foils.

[0058] Dry thin rolling, dry lamination, and dry roll plating of the active material or metal foils made of active material are preferably carried out in a dry room and / or in a protective gas atmosphere, such as helium or argon. This prevents surface reactions and the formation of surface reaction products.

[0059] The dry production of metal foils or metal composite foils from active material can be used to improve their purity in a particularly advantageous manner.

[0060] The active material is formed from chemically active substances that are particularly required for energy storage in batteries. The active material is preferably lithium, sodium, magnesium, calcium, an alloy of the aforementioned active materials, or an alloy of at least two different aforementioned active materials, which is dry-rolled into a metal foil using tool 6.

[0061] As an electrically conductive carrier material, preferably copper or aluminum or nickel or steel or an alloy thereof is dry-rolled into a metal foil.

[0062] Preferably, in a further work step, a metal foil made of lithium or sodium or magnesium or calcium, which has been dry-rolled thin with the tool 6, and a metal foil made of copper or aluminum or nickel or steel, which has been dry-rolled thin with the tool 6, are dry-laminated or plated with the tool 6 to form a metal composite foil.

[0063] The lithium, sodium, magnesium, or calcium can alternatively consist of an alloy of the same or of an alloy of at least two different active materials. These can also be passivated, particularly for protection during transport.

[0064] Furthermore, the copper or aluminum or nickel or steel may alternatively consist of an alloy of the aforementioned electrically conductive carrier material or of an alloy of at least two of these carrier materials.

[0065] A metal foil made of active material according to the invention preferably consists of lithium or sodium or magnesium or calcium dry-rolled thin with the tool 6.

[0066] The metal foil can alternatively consist of an alloy of the aforementioned active materials, dry-rolled thin with the tool 6, or of an alloy of at least two different aforementioned active materials, such as lithium magnesium, or further alloys of the aforementioned materials, such as lithium indium, lithium boron, lithium silicon, lithium aluminum, lithium tin, lithium zinc, dry-rolled thin with the tool 6.

[0067] The dry-rolled metal foils each have a thickness that is preferably less than 100 µm.

[0068] The metal foil can also be produced as a metal composite foil using the tool and method described above. It consists of a lithium foil, sodium foil, magnesium foil, or calcium foil, dry-rolled thin using tool 6, which is dry-laminated or plated on one or both sides of a copper foil, aluminum foil, nickel foil, or steel foil, dry-rolled thin using tool 6, as an electrically conductive carrier material. The metal composite foil can consist of a foil of carrier material with a foil of active material dry-laminated or plated on one or both sides. This results in the advantages already described above. In addition, the electrically conductive carrier material can also serve cost-effectively as an electrical conductor.

[0069] In this way, for example, a metal composite foil made of copper and lithium, of copper and an alloy of lithium and magnesium, or of copper and an alloy of lithium and indium can be dry laminated or plated.

[0070] In a particularly advantageous manner, the dry-rolled thin metal foils are free or at least largely free from contamination by lubricants, glidants or release agents.

[0071] The above-described dry-laminated or plated metal composite foils or the above-described dry-thin rolled metal foils made of the above-mentioned active materials can be used in a particularly advantageous manner for the production of new generations of rechargeable secondary batteries, such as metal or solid-state batteries, and in particular for the production of anodes of these batteries with the above-mentioned active material.

[0072] These anodes consist of the active material described above and a current conductor. They can be formed particularly simply using the metal composite foils described above, with the current conductor being formed by the electrically conductive carrier material of the metal composite foils. List of reference symbols 1 outer layer, layer arrangement 2 Tool surface 3 Intermediate layer, layer arrangement 4 line, multi-layer structure 5 line, multi-layer structure 6 Tool, roller, working drum

Claims

[1] Layer arrangement (1, 3) for coating a tool surface (2) for producing thin metal foils of active material for anodes of a battery, characterized by that for the dry production of the metal foils, an outer layer (1) which has a non-stick effect with respect to the active material and at least one intermediate layer (3) located between the outer layer (1) and the tool surface (2) for increasing the adhesion between the outer layer (1) and the tool surface (2) is provided, wherein the intermediate layer (3) is metallic and consists of zirconium, titanium, vanadium, molybdenum, tungsten or chromium or of a nitride of these metals or is constructed in several layers from the aforementioned materials or from a combination of at least two of these materials. [2] Layer arrangement according to claim 1, characterized bythat the outer layer (1) is based on carbon or contains boride or diboride or is formed as a ceramic coating or as a polymer coating or from a combination of at least two of these materials or is constructed in multiple layers from the aforementioned materials. [3] Tool (6) with a layer arrangement on the tool surface (2) according to one of claims 1 or 2, for the dry production of thin metal foils of active material for anodes of a battery. [4] Tool (6) according to claim 3, characterized bythat at least one roller or working drum is provided for the dry thin rolling of the active material or an electrically conductive carrier material as a metal foil and / or at least one roller or working drum for the dry lamination or dry plating of at least one metal foil made of active material on a metal foil made of electrically conductive carrier material as a metal composite foil and / or at least one deflection roller for the dry changing of the direction of movement of the metal foil, wherein each roller, working drum or deflection roller has an aforementioned layer arrangement (1, 3) on the tool surface (2). [5] Method for producing thin metal foils of active material for anodes of a battery, with a tool (6) according to one of claims 3 or 4, characterized bythat pure active material or an alloy thereof and / or electrically conductive carrier material or an alloy thereof are each dry-rolled thin to form a metal foil and / or at least one metal foil made of the active material and at least one metal foil made of an electrically conductive carrier material are dry-laminated to form a metal composite foil. [6] Method according to claim 5, characterized by that lithium or sodium or magnesium or calcium or an alloy of the aforementioned active materials is dry-rolled into a metal foil as the active material. [7] Method according to one of claims 5 or 6, characterized bythat copper or aluminum or nickel or steel or an alloy thereof is dry-rolled thin to form a metal foil as the electrically conductive carrier material and in a further work step a dry-rolled thin metal foil made of the aforementioned active material and the dry-rolled thin metal foil made of the aforementioned electrically conductive carrier material are dry-laminated or plated to form a metal composite foil.

Images