GALVANIC MONOCELL AND METHOD FOR PRODUCING THE SAME

Abstract

A monocell and a method for producing a monocell for a battery cell. In this method, a first separator film, an anode film, a second separator film, and a cathode film are stacked in this sequence to form a film layer arrangement and fed to a thermal cutting process. The cutting of the film layer arrangement is accomplished by a thermal cutting method, wherein a first metal coating on the anode film and a second metal coating on the cathode film vaporize in the cut region. The plastic substrate of the anode melts partially and spreads over the cut surface of the first anode layer and electrically insulates the same. The plastic substrate of the cathode melts partially and spreads over the cut surface of the first cathode layer and electrically insulates the same.

Claims

1. A method for producing a monocell for a battery cell, the method comprising: feeding a first separator film to electrically separate an anode and a cathode of the battery cell; feeding an anode film that has a first current conductor and a first anode layer and a second anode layer, which embed the first current conductor between the first and second anode layers; feeding a second separator film to electrically separate an anode and a cathode of the battery cell; feeding a cathode film that has a second current conductor and a first cathode layer and a second cathode layer, which embed the second current conductor between the first and the second cathode layers, wherein at least one of the current conductors is produced from a plastic substrate that is provided with a metal coating; producing a film layer arrangement from the first separator film, the anode film, the second separator film, and the cathode film; and cutting the film layer arrangement via a thermal cutting method such that the metal coating on the plastic substrate vaporizes, and the plastic substrate melts partially and spreads over the cut surface of the first anode layer or of the first cathode layer and electrically insulates the same.

2. The method for producing a monocell according to claim 1, wherein the anode film has a first current conductor made of a first plastic substrate that is provided with a first metal coating, wherein the cathode film has a second current conductor made of a second plastic substrate that is provided with a second metal coating, wherein, during cutting of the film layer arrangement via the thermal cutting method, the first metal coating on the anode film and the second metal coating on the cathode film vaporize in the cut region, wherein the first plastic substrate melts partially and spreads over the cut surface of the first anode layer and electrically insulates the same, and wherein the second plastic substrate melts partially and spreads over the cut surface of the first cathode layer and electrically insulates the same.

3. The method for producing a monocell according to claim 1, wherein the films of the film layer arrangement are laminated to one another, and consequently a film composite is formed, prior to the cutting.

4. The method for producing a monocell according to claim 1, wherein the films of the film layer arrangement are pressed together by a compression unit. The method for producing a monocell according to claim 1, wherein the thermal cutting method is a laser cutting method.

6. The method for producing a monocell according to claim 5, wherein a laser cuts the film layer arrangement in the following sequence: cathode film, second separator film, anode film, and first separator film.

7. The method for producing a monocell according to claim 1, wherein an auxiliary joining material is applied in a cutting gap during the thermal cutting process, the auxiliary joining material electrically insulating the anode and the cathode from one another at a cut edge.

8. The method for producing a monocell according to claim 7, wherein the auxiliary joining material is a plastic.

9. The method for producing a monocell according to claim 1, wherein a melted plastic substrate or an auxiliary joining material additionally covers the cut edge of a separator film.

10. A monocell for producing a cell stack in a battery cell, the monocell comprising: a first separator layer; an anode having a first anode layer and a second anode layer and a first current conductor arranged between the first anode layer and the second anode layer, the first current conductor having a plastic substrate with a metal coating; a second separator layer; and a cathode having a first cathode layer and a second cathode layer and a second current conductor arranged between the first cathode layer and the second cathode layer, the second current conductor having a plastic substrate with a metal coating, wherein the monocell is produced by the method according to claim 1.

11. The monocell according to claim 10, wherein the metal coating of the plastic substrate of the anode is a copper or nickel coating.

12. The monocell according to claim 10, wherein the metal coating of the plastic substrate of the cathode is an aluminum coating.

13. The monocell according to claim 10, wherein the plastic substrate of the anode and the plastic substrate of the cathode are thicker than the metal coatings of the respective plastic substrate.

14. The monocell according to claim 13, wherein the plastic substrate has a material thickness of 5-50 μm and the metal coatings have a layer thickness of 1-5 μm.

15. The monocell according to claim 10, wherein the plastic substrate is a thermoplastic substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0037] FIG. 1 is a system for producing a galvanic monocell according to the invention for a cell stack of a battery cell;

[0038] FIG. 2 is an enlarged representation of a cutting zone where the film material is cut and singulated into monocells according to the invention,

[0039] FIG. 3 is a monocell according to the invention for producing a cell stack in a battery cell; and

[0040] FIG. 4 is a flowchart for producing a monocell according to the invention for a cell stack in a battery cell.

DETAILED DESCRIPTION

[0041] FIG. 1 shows a system 60 for carrying out a method according to the invention for producing galvanic monocells 10 for a cell stack of a battery cell. The system 60 has a first feeding device 62 for feeding an anode film 16 and a second feeding device 64 for feeding a first separator film 14. The system 60 furthermore has a third feeding device 66 for feeding a second separator film 18 and a fourth feeding device 68 for feeding a cathode film 12. The films 12, 14, 16, 18 in this case are stacked in the following order: first separator film 14, anode film 16, second separator film 18, and cathode film 12, so that a film layer arrangement 86 is produced. The system 60 additionally includes a conveyor unit 70, which feeds the individual films 12, 14, 16, 18 to a cutting unit 76. The system can furthermore have a compressor 72 and/or a laminating unit 74 in order to compress the films 12, 14, 16, 18 prior to cutting, and to fix them in place relative to one another by a laminating process. In this way, a continuous film composite 88 can be produced that can comprise all components of the monocell 10.

[0042] The cutting unit 76 preferably includes one or more lasers 78, with which the film layer arrangement 86 or the film composite 88 is singulated into monocells 10. For this purpose, the film layer arrangement 86 or the film composite 88 is thermally detached from the continuously fed film material of the films 12, 14, 16, 18 in a melt zone 82. In the melt zone, a metal coating 34, 54 is vaporized onto the current conductors 38, 58 of the anode film 16 or of the cathode film 12, and a plastic substrate 28, 48 of the corresponding current conductor 38, 58 is melted. Furthermore, the cutting unit 76 can have an application unit for an auxiliary joining material, which can be placed in the cutting gap between the film layer arrangement 86 or the film composite 88 and the monocell 10. The system 60 further includes a receiving device 80 for receiving the singulated monocells 10 and making them available for further processing in a next process step.

[0043] The system 60 further includes a controller 90 with a memory unit 92 and a computing unit 94 as well as machine-readable program code 96 stored in the memory unit 92. The controller 90 is equipped to carry out a method according to the invention for producing a monocell 10 with such a system 60 when the machine-readable program code 96 is executed by the computing unit 94.

[0044] In FIG. 2, a schematic representation is shown of a cutting zone during a thermal cutting process for producing a monocell 10 according to the invention, in which the film material of the film layer arrangement 86 or of the film composite 88 is cut with a thermal cutting element 76, in particular a laser 78, and singulated into monocells according to the invention. The fed film layer arrangement 86 or the fed film composite 88 comprises a first separator film 14, an anode film 16, a second separator film 18, and a cathode film 12. The anode film 16 comprises a first anode layer 22 and a second anode layer 24, which embed an anode substrate 26 in the form of a plastic substrate 28 with a first metal coating 34, in particular a copper coating 36. The cathode film 12 comprises a first cathode layer 42 and a second cathode layer 44, which embed a cathode substrate 46 in the form of a plastic substrate 48 with a second metal coating 54, in particular an aluminum coating 56. The metal-coated plastic substrates 28, 48 serve as current conductors 38 of the cathode 12 or of the anode 16, respectively. The thermal cutting element 76 comprises one or more lasers 78, with which the film layer arrangement 86 or the film composite 88 is severed, and consequently individual monocells 10 are detached from this film layer arrangement 86 or this film composite 88. In the process, the film layer arrangement 86 or the film composite 88 is severed by the thermal cutting unit 76, 78, starting from the cathode film 12. The metal coatings 34, 54 of the plastic substrates 28, 48 are vaporized and the plastic of the plastic substrate 28, 48 is melted in a melt zone 82 in the process. The melted plastic from the plastic substrate 48 of the cathode 40 distributes itself over the cut surface of the first cathode layer 42 and, if applicable, additionally over the cut surface of the second separator film 18 in the process. The melted plastic from the plastic substrate 28 of the anode 20 distributes itself over the cut surface of the first anode layer 22 and, if applicable, additionally over the cut surface of the first separator film 14 in the process. In this way, the cut surfaces are electrically insulated so that the risk of a short circuit in the monocell 10 is prevented.

[0045] Shown in FIG. 3 is a galvanic monocell 10 according to the invention that is produced with a method according to the invention. The galvanic monocell 10 comprises a first separator layer 39, an anode 20, a second separator layer 59, and a cathode 40. The anode 20 has a first anode layer 22 and a second anode layer 24, which embed an anode substrate 26. The anode substrate 26 has a first plastic substrate 28 that has a metal coating 34, in particular a copper coating 36, on a first surface 30 facing the first anode layer 22 and on a second surface 32 facing the second anode layer 24. The first plastic substrate 28 with the first metal coating 34 serves as current conductor 38 of the anode 20.

[0046] The cathode 40 of the galvanic monocell 10 has a first cathode layer 42 and a second cathode layer 44, which embed a cathode substrate 46. The cathode substrate 46 has a second plastic substrate 48 that has a metal coating 54, in particular an aluminum coating 56, on a first surface 50 facing the first cathode layer 42 and on a second surface 52 facing the second cathode layer 44. The second plastic substrate 48 with the second metal coating 54 serves as current conductor 58 of the cathode 40.

[0047] Because more material is removed at the cathode 40 than at the anode 20 owing to the thermal cutting method and the chosen cutting direction, the cathode 40 is smaller than the anode 20 located beneath it in the cutting direction.

[0048] The cut surfaces of the first cathode layer 42 and the cut surfaces of the first anode layer 22 are wetted, and thus electrically insulated, by the melting plastic from the relevant plastic substrate 28, 48 located thereover.

[0049] In FIG. 4, a flowchart for carrying out a method according to the invention for producing a galvanic monocell 10 is shown. In a method step <100>, a first separator film 14 for electrical separation of an anode 20 and a cathode 40 of the monocell 10 is fed. In a method step <110>, an anode film 16 is fed, wherein the anode film 16 has a first current conductor 38 made of a first plastic substrate 28 that is provided with a first metal coating 34, and also has a first anode layer 22 and a second anode layer 24, which embed the first current conductor between the first and second anode layers 22, 24. In a method step <120>, a second separator film 18 for electrical separation of an anode 20 and a cathode 40 of the monocell 10 is fed. In a method step <130>, a cathode film 12 is fed, wherein the cathode film 12 has a second current conductor 58 made of a second plastic substrate 48 that is provided with a second metal coating 54, and also has a first cathode layer 42 and a second cathode layer 44, which embed the second current conductor 58 between the first and the second cathode layers 42, 44.

[0050] In a method step <140>, a film layer arrangement 86 is produced from the first separator film 14, the anode film 16, the second separator film 18, and the cathode film 12. In a method step <150>, this film layer arrangement can be pressed together and joined together in a laminating process to form a film composite 88. However, this step can also be omitted in a simplified embodiment of the method.

[0051] In a method step <150>, the film layer arrangement 86 or the film composite 88 is cut by means of a thermal cutting method, wherein the first metal coating 34 on the anode film 16 and the second metal coating 54 on the cathode film vaporize in the cut region. In the process, the first plastic substrate 28 melts partially and spreads over the cut surface of the first anode layer 22, thus electrically insulating the same. Furthermore, the second plastic substrate 48 melts partially and spreads over the cut surface of the first cathode layer 42, thus electrically insulating the same. In a method step <170>, the monocell 10 cut from the film composite 88 or from the film layer arrangement 86 is received in a receiving unit 80, and can be fed to the further production process for producing a cell stack for a battery cell.

[0052] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.