Cell contacting system, cell module and method for manufacturing a cell module

Abstract

Cell contacting system (3) for a cell module (1) comprising at least two electrochemical cells (2), comprising at least one support component (5) that can be fixed to the remaining cell module (4) for carrying at least one cell connector (6) that electrically connects the two electrochemical cells (2) together and at least one cover component (11) covering the cell connector (6) on a side facing away from the electrochemical cells (2), characterized in that the cover component (11) is made of a flexible plastic film and is partially bonded to the support component (5) in a tensioned state.

Description

[0001] The invention relates to a cell contacting system for a cell module comprising at least two electrochemical cells, comprising at least one carrier component which can be fixed to the remaining cell module for carrying at least one cell connector which electrically interconnects the two electrochemical cells, and at least one covering component which covers the cell connector on a side facing away from the electrochemical cells.

[0002] Furthermore, the invention comprises a cell module with at least two electrochemical cells and at least one cell contacting system for electrically connecting the electrochemical cells to one another.

[0003] Furthermore, the invention relates to a method for producing a cell module.

[0004] Electrically powered motor vehicles, particularly hybrid vehicles and electric vehicles, use rechargeable batteries that contain a multitude of electrically interconnected electrochemical cells. These batteries can be used to supply electrical energy to the electric drive systems of the electrically powered motor vehicles. The electrochemical cells can be combined into electrically interconnected battery subunits, known as cell modules.

[0005] DE 10 2011 076 889 A1 discloses a cover for an electrochemical device comprising a plurality of electrochemical cells, which cover comprises a carrier element on which at least one cell connector is arranged for electrically connecting a first cell terminal of a first electrochemical cell and a second cell terminal of a second electrochemical cell. Furthermore, a cover element for covering the at least one cell connector is provided on the cover, wherein the cover element comprises a cover film.

[0006] Since high electrical currents flow through a cell module, the cell module's electrical components must be located inaccessible from the outside. Furthermore, the components must be protected against external mechanical influences. To achieve this, it is known to install a contact guard on a cell module, covering the side of the cell module where the electrochemical cells are electrically interconnected via cell connectors. The cover component used for this purpose is usually rigid. The cover component can be designed, for example, as an injection-molded or thermoformed component. The cover component is usually manually applied to the rest of the cell module and locked into place.

[0007] An object of the invention is to provide an automated and cost-effective cell contact system with integrated contact protection.

[0008] This problem is solved by the independent patent claims. Advantageous embodiments are particularly recited in the dependent patent claims, each of which, taken individually or in various combinations, may represent an aspect of the invention.

[0009] A cell contacting system according to the invention for a cell module having at least two electrochemical cells comprises at least one support component that can be secured to the remaining cell module for supporting at least one cell connector that electrically interconnects the two electrochemical cells, and at least one cover component that covers the cell connector on a side facing away from the electrochemical cells. According to the invention, the cover component is made of a flexible plastic film and, in a tensioned state, is partially bonded to the support component.

[0010] The cover component according to the invention is not rigidly constructed as is conventional and is manufactured with a specific shape in a previous process. Therefore, no corresponding molding tools are required to produce the cover component according to the invention, which makes the production of the cover component according to the invention and thus of the cell contacting system according to the invention more cost-effective.

[0011] Furthermore, the production of the cell contact system according to the invention requires no manual steps and is therefore fully automated, which also saves manufacturing costs. In contrast, conventional contact protection must be manually connected to the rest of the cell module.

[0012] The invention further has the advantage that a flexible plastic film, for example, as a roll material, is used to form the cover component, which is significantly more cost-effective than the conventional use of, for example, a thermoformable plastic blank. The inventive use of a flexible plastic film to form the cover component also results in very high manufacturing flexibility with regard to different cell module sizes and thus cover components of different sizes.

[0013] A cell contacting system according to the invention can also comprise three or more, in particular a plurality of, electrochemical cells that can be electrically interconnected in pairs. The electrochemical cells can be configured, for example, as lithium-ion storage cells, lithium polymer storage cells, or nickel-metal hybrid storage cells.

[0014] The support component can be attached to the rest of the cell module in a force-fitting, form-fitting, and / or material-fitting manner. Preferably, the support component can be detached from the rest of the cell module without causing damage, for example, to enable inspection and / or maintenance work on the cell module. The support component can also carry two or more cell connectors with which at least three electrochemical cells can be electrically interconnected. The support component is a single-part or multi-part component made of an electrically insulating material. Furthermore, the support component can fulfill other functions, such as insulating the cell sidewalls.

[0015] The fact that the cover component covers the at least one cell connector on a side facing away from the electrochemical cells is intended to mean that the cell connector is not accessible from this side of the cell module, so that the cover component forms optimal contact protection.

[0016] To produce the cell contacting system or the cover component according to the invention, a film section of a predetermined size can first be pulled from a supply roll and then separated from the remaining plastic film. The separated film section or the flexible plastic film can then be stretched to extend essentially in one plane. In this stretched state, the flexible plastic film can be arranged on the carrier component and then partially bonded to the carrier component. One or more of these operations, in particular all operations, can be carried out automatically. The partially bonded connection of the cover component to the carrier component is preferably carried out in such a way that the bonded connection maintains the stretched state of the cover component as permanently as possible.The material connection can, for example, be provided in the form of two connecting lines running parallel to each other and spaced apart from each other. Alternatively, the material connection can be provided in the form of a closed, particularly O-shaped, connecting line.

[0017] The integral bond between the cover component and the carrier component can be created in various ways. For example, the integral bond can be formed by (thermal) sealing, welding, or bonding. Such a bond can be achieved, for example, by laser welding.

[0018] According to an advantageous embodiment, the support component comprises a base on which the cell connector is arranged, and a side wall arranged at least partially circumferentially on the base and facing away from the electrochemical cells, wherein the cover component is integrally connected to the side wall. The cover component can be held at a distance from the at least one cell connector via the side wall arranged partially or completely circumferentially on the base.

[0019] According to an alternative, further advantageous embodiment, the support component comprises a base on which the cell connector is arranged, a first side wall arranged at least partially circumferentially on the base and facing away from the electrochemical cells, and a second side wall connected to the first side wall and at least partially enclosing the first side wall at a distance from the outside, wherein the second side wall projects beyond the first side wall on the side facing away from the electrochemical cells, and wherein the cover component is optionally materially connected to one of the two side walls. The cover component can be held at a distance from the at least one cell connector via the first side wall arranged partially or completely circumferentially on the base or the second side wall partially or completely enclosing the first side wall at a distance from the outside.If the cover component is initially connected to the second side wall, the material-to-material connection between the second side wall and the cover component can be at least partially released if necessary, in particular with partial destruction of the cover component in the region of the material-to-material connection. Subsequently, the section detached from the second side wall can be material-to-material connected to the first side wall at another location within the section. This is particularly possible because the first side wall defines a smaller area for arranging the cover component than the second side wall. Consequently, at least partial removal and reattachment of the cover component to the support component via another material-to-material connection is possible.

[0020] A further advantageous embodiment provides for the cover component to be integrally connected to a free end of the side wall. The free end of the respective side wall is easily accessible from the outside, which simplifies the creation of the integral connection between the cover component and the support component.

[0021] A cell module according to the invention comprises at least two electrochemical cells and at least one cell contacting system for electrically connecting the electrochemical cells to one another, wherein the cell contacting system is designed according to one of the aforementioned embodiments or any combination thereof.

[0022] The cell module offers the advantages mentioned above with regard to the cell contact system. The cell module can be used to form a rechargeable battery for an electrically powered motor vehicle.

[0023] A method according to the invention for producing a cell module comprises the steps: - producing a compact assembly comprising at least two electrochemical cells and optionally a housing partially enclosing the electrochemical cells; - Arranging a carrier component on the electrochemical cells, on which at least one cell connector for electrically connecting the two electrochemical cells to one another is arranged; - material connection of the cell connector to one electrical connection each of the two electrochemical cells; - Arranging a cover component made of a flexible plastic film in a tensioned state on the carrier component; and - partial material connection of the cover component with the support component.

[0024] The method accordingly provides the advantages mentioned above with reference to the cell contacting system. The production of the compact assembly can comprise an immediately adjacent arrangement of the electrochemical cells in a row. In addition, the electrochemical cells thus combined can be arranged in a housing that at least laterally encloses the electrochemical cells. Arranging the carrier component on the electrochemical cells or the housing can comprise a positive and / or non-positive connection, for example, a locking connection, of these components. The integral connection of the cell connector to the respective electrical terminal of an electrochemical cell can be achieved by a welding process. Some or all steps of the method according to the invention can be carried out automatically.

[0025] According to an advantageous embodiment, the flexible plastic film is automatically pulled from a supply roll and cut to length to produce the cover component. This results in a simple, flexible, automated, and cost-effective production of the cover component.

[0026] Further details, features, and advantages of the invention will become apparent from the following description and the figures. They show: Fig. 1 is a schematic sectional view of an embodiment of a cell module according to the invention; and Fig. 2 a schematic sectional view of a detail of the Fig. 1 shown cell module.

[0027] Fig. 1 shows a schematic sectional view of an embodiment of a cell module 1 according to the invention. The cell module 1 comprises at least two electrochemical cells 2, of which Fig. 1, only one is shown. Furthermore, the cell module 1 comprises a cell contact system 3 for electrically connecting the electrochemical cells 2 to one another.

[0028] The cell contacting system 3 comprises a carrier component 5 fixed to the remaining cell module 4 for carrying at least one cell connector 6 electrically interconnecting the two electrochemical cells 2.

[0029] The support component 5 comprises a base 7 on which the cell connector 6 is arranged. Furthermore, the support component 5 comprises a first side wall 8 arranged circumferentially on the base 7 and pointing away from the electrochemical cells 2. In addition, the support component 5 comprises a second side wall 9 which is connected to the first side wall 8 and surrounds the first side wall 8 at a distance on the outside. The second side wall 9 can project beyond the first side wall 8 on the side facing away from the electrochemical cells 2 or can be designed at the same height. The first side wall 8 is connected to the second side wall 9 via a circumferential web 10. The support component 5 is monolithic.

[0030] The cell contacting system 3 also comprises a cover component 11 covering the cell connector 6 on a side facing away from the electrochemical cells 2 and the electrochemical cells 2. The cover component 11 is made of a flexible plastic film and, in a tensioned state, is partially integrally connected to the support component 5. In particular, the cover component 11 is integrally connected to the second side wall 9 along a closed connecting line. The cover component 11 is connected to a free end 12 of the second side wall 9 via an integral connection 13.

[0031] Fig. 2 shows a schematic sectional view of a detail of the Fig.1. This illustration shows two alternative arrangements of the cover component 11 on the support component 5, wherein the cover component 11 is optionally materially connected to one of the two side walls 8 or 9. The cover component 11 can initially be materially connected to the free end 12 of the second side wall 9. If necessary, the materially bonded connection 13 between the cover component 11 and the second side wall 9 can be at least partially detached or the cover component 11 can be destroyed in this area in order to make the cell connector 6 and the electrochemical cells 2 accessible. Depending on the design, either only the cover component 11 can be destroyed or the cover component together with the support component 5. The latter is destroyed in such a way that the second side wall 9 is no longer present afterwards.The cover component 11 can then be materially connected to the free end face 12 of the first side wall 8, whereby the cover component 11 can be reused. List of reference symbols: 1 cell module 2 electrochemical cell 3 Cell contact system 4 remaining cell module 5 Support component 6 cell connectors 7 bottom of 5 8 first side wall of 5 9 second side wall of 5 10 bridges out of 5 11 Cover component 12 free front end of 8, 9 13 material connection

Claims

[1] Cell contacting system (3) for a cell module (1) comprising at least two electrochemical cells (2), comprising at least one support component (5) which can be fixed to the remaining cell module (4) for supporting at least one cell connector (6) which electrically interconnects the two electrochemical cells (2) and at least one cover component (11) covering the cell connector (6) on a side facing away from the electrochemical cells (2), characterized by that the cover component (11) is made of a flexible plastic film and is partially materially connected to the carrier component (5) in a tensioned state. [2] Cell contacting system (3) according to claim 1, characterized byin that the carrier component (5) has a base (7) on which the cell connector (6) is arranged, and a side wall (8) arranged at least partially circumferentially on the base (7) and pointing away from the electrochemical cells (2), wherein the cover component (11) is integrally connected to the side wall (8). [3] Cell contacting system (3) according to claim 1, characterized byin that the support component (5) has a base (7) on which the cell connector (6) is arranged, a first side wall (8) arranged at least partially circumferentially on the base (7) and pointing away from the electrochemical cells (2), and a second side wall (9) connected to the first side wall (8) and at least partially circumferentially enclosing the first side wall (8) at a distance from it, wherein the second side wall (9) projects beyond the first side wall (8) on the side facing away from the electrochemical cells (2), and wherein the cover component (11) is optionally connected in a materially bonded manner to one of the two side walls (8, 9). [4] Cell contacting system (3) according to claim 2 or 3, characterized by that the cover component (11) is integrally connected to a free end face (12) of the side wall (8, 9). [5] Cell module (1) with at least two electrochemical cells (2) and at least one cell contact system (3) for electrically connecting the electrochemical cells (2) to one another, characterized by that the cell contacting system (3) is designed according to one of claims 1 to 4. [6] Method for producing a cell module (1), comprising the steps: - producing a compact assembly comprising at least two electrochemical cells (2) and optionally a housing partially enclosing the electrochemical cells (2); - arranging a carrier component (5) on the electrochemical cells (2), on which at least one cell connector (6) for electrically connecting the two electrochemical cells (2) to one another is arranged; - materially connecting the cell connector (6) to an electrical connection of each of the two electrochemical cells (2); - Arranging a cover component (11) made of a flexible plastic film in a tensioned state on the carrier component (5); and - partial material connection of the cover component (11) to the support component (5). [7] Method according to claim 6, characterized by that the flexible plastic film is automatically pulled off a storage roll and cut to length to produce the cover component (11).

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