Cell connector for establishing an electrical contact between a first pole of a first battery cell and a second pole of a second battery cell, and battery assembly

Abstract

The invention relates to a cell connector (20) for establishing an electrical contact between a first pole (14) of a first battery cell (12) and a second pole (18) of a second battery cell (16), wherein the cell connector (20) is designed for welding to the poles (14, 18), wherein the cell connector (20) is of a substantially U-shaped form and is supported on the first pole (14) by a first leg (24) of the U shape and on the second pole (18) by a second leg (26) of the U shape, which is formed opposite the first leg (24). The invention also relates to a battery assembly (10).

Description

[0001] Cell connector for electrically contacting a first pole of a first battery cell with a second pole of a second battery cell and battery arrangement

[0002] The invention relates to a cell connector for electrically contacting a first pole of a first battery cell with a second pole of a second battery cell according to the preamble of patent claim 1. Furthermore, the invention relates to a battery arrangement.

[0003] To electrically connect individual battery cells, especially so-called prismatic hard-case cells, to a battery module, the current state of the art involves welding flat, large-area cell connectors onto the corresponding cell terminals, particularly by laser welding. A disadvantage is that battery modules feature a cell connector that serves no other function than electrically contacting the cells. Furthermore, battery modules have large-area and therefore heavy frame components that must stiffen the module structure to prevent potential cell thickness growth or similar.

[0004] As an introduction: DE 102007 063 177 A1 relates to a cell connector for connecting two poles of cells of batteries, in particular for batteries of hybrid-powered motor vehicles, which cell connector has two openings, wherein in the region of each opening a compensating element is arranged between the cell connector and the pole, wherein the compensating element and cell connector as well as the compensating element and the pole can each be connected to one another in a materially bonded manner.

[0005] The object of the present invention is to provide a cell connector and a battery arrangement which can be used in a highly functional manner.

[0006] This object is achieved by a cell connector and a battery assembly according to the independent patent claims. Advantageous embodiments are specified in the subclaims. One aspect of the invention relates to a cell connector for electrically contacting a first pole of a first battery cell with a second pole of a second battery cell, wherein the cell connector is designed to be welded to the poles.

[0007] It is provided that the cell connector is substantially U-shaped and is supported with a first leg of the U-shape on the first pole and with a second leg of the U-shape, which is formed opposite to the first leg, on the second pole.

[0008] In particular, a cell connector is proposed which, in addition to the properties of current conduction, also assumes at least part of the overall structural strength of the battery module. In particular, the cell connector has, for example, a thickness T of greater than or equal to 0.5 millimeters, and the U-shape or the so-called collar is shaped accordingly, which ensures a positive connection between the cell connector and two adjacent, in particular at least two adjacent, cell terminals. The collar of the cell connector acts in particular transversely to the direction of load. When the battery cell expands, the main load is absorbed by the positive connection and not by the contact welds, so that these remain undamaged.The cell connector mechanically connects the battery cells on the top side by enclosing at least two adjacent cell terminals, while a reduced base profile can be used on the bottom side, for example. The distance between cells can be precisely adjusted using flexibly deformable spacers, such as tension mats, a sealant, or an adhesive, allowing the positive fit of the terminals with the cell connector to be precisely adjusted during assembly.

[0009] In particular, this leads to a reduction in structural components and thus the weight of the battery modules. Furthermore, the cell connector is particularly suitable for use with large battery cells, especially when the material thickness is greater than or equal to 0.5 millimeters, with the cell connector being made primarily of aluminum. Furthermore, simplified assembly and production can be achieved due to the elimination of parts and joining costs. Furthermore, easy integration into current production processes and simple manufacture of the cell connectors, for example, through bending or extrusion, can be realized. The cell connector can also be used as an additional stiffener in conventional battery modules to increase overall strength.The cell connector is particularly suitable for all cell types, but is particularly well-suited for connecting prismatic hard-case cells. The additional form-fit connection can improve the current-carrying capacity. In particular, the cell connector and terminal can also be joined, for example, by bonding, in the collar area for greater strength.

[0010] A further advantageous embodiment provides that the cell connector is arranged in the region of the first leg and the second leg with a weld on the first pole and the second pole. In particular, the weld can be laser welded.

[0011] Furthermore, it has proven advantageous if the cell connector is designed in a frame-like manner and has a respective recess in the region of the poles. The frame-like structure can enclose the first pole and the second pole in a single recess. Alternatively, the frame-like structure can enclose the first pole with a first recess and the second pole with a second recess. For example, the frame-like structure can be S-shaped in a direction perpendicular to the U-shape.

[0012] In particular, the use of the cell connector in frame form is envisaged, which completely or at least partially surrounds or encloses the terminal(s), i.e., poles, of the battery cells. The cell connector can preferably rest on the top (in the z-direction), either fully or partially, or in a frame-like manner, on the terminals and, in particular, rests against them laterally (in the x / y direction). This can enable the welding of fillet or I-welds with lower energy and improved and controlled connection in the innovative joint, for example, with I-welds at butt joints or fillet welds with a low cell connector height. The cell connectors offer improved current flow in the possible shape variants.Depending on the cell connector design and dimensions, the distance between the terminals can be defined and always precisely adjusted using flexible spacers applied between the cells, particularly so-called tension mats, sealant, or adhesive. This makes it possible, in particular, to significantly reduce the terminal area of ​​the battery cells in a component and joining arrangement, opening up new design possibilities. In particular, a stable and reliable process can be achieved using I-welds at the butt or lap joint or fillet welds, depending on the cell connector design. Furthermore, the new design enables improved current-carrying properties between the cells, as well as simplified quality assurance and an increased connection area.Furthermore, repair options are improved, and in particular, the application can be implemented using conventional equipment technology, with laser scanner welding being particularly suitable. Furthermore, this is particularly suitable for welding metallic terminals to the cell connector made of, for example, aluminum and / or copper, or similar aluminum-aluminum and / or copper, or copper, or their mixed aluminum-copper. The cell connector can be made as thick as desired toward the outside. This aspect is also, in particular, an independent aspect of the invention.

[0013] A further advantageous embodiment provides for the legs to have a thickness of at least 0.5 millimeters. This provides a structurally stable cell connector that can also absorb forces during cell thickness growth, for example.

[0014] It is also advantageous if the weld is designed as a fillet weld or I-weld. This allows for simple yet reliable welding of the cell connector to the poles.

[0015] In a further advantageous embodiment, the battery cells are designed, in particular, as hard-case cells. In particular, the cell connector is thus provided for hard-case cells.

[0016] A further aspect of the invention relates to a battery arrangement having a first battery cell with a first pole and having a second battery cell with a second pole, wherein the first pole is electrically connected to the second pole by means of a cell connector according to the preceding aspect.

[0017] Advantageous embodiments of the cell connector are to be regarded as advantageous embodiments of the battery arrangement.

[0018] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0019] Showing:

[0020] Fig. 1 is a schematic side view of an embodiment of a battery arrangement;

[0021] Fig. 2 is a schematic flow diagram for producing a battery assembly; and

[0022] Fig. 3 different embodiments of an embodiment of a cell connector.

[0023] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0024] Fig. 1 shows a schematic side view of an embodiment of a battery arrangement 10 with a first battery cell 12 with a first pole 14 and with a second battery cell 16 with a second pole 18. It goes without saying that the battery arrangement 10 can also have further battery cells 12, 16. Furthermore, the respective battery cells have at least one further pole (not shown), wherein the poles can also be referred to as terminals. The battery arrangement 10 has at least one cell connector 20, which electrically contacts the first pole 14 and the second pole 18. For this purpose, it can be provided, for example, that the cell connector 20 is welded to the poles 14, 18 via corresponding weld seams 22.

[0025] In particular, it is shown that the cell connector 20 is substantially U-shaped, wherein the cell connector 20 is supported with a first leg 24 of the U-shape on the first pole 14 and with a second leg 26 of the U-shape, which is formed opposite the first leg 24, on the second pole 18. In particular, it is shown that the cell connector 20 can also be welded to the first pole 14 and the second pole 18 in the region of the two legs 24, 26. In particular, the weld seam can again be created using laser welding. The weld seam is preferably a fillet weld or an I-seam, for example. The battery cells 12, 16 are designed in particular as hardcase cells in the present exemplary embodiment.

[0026] Furthermore, it is shown that the legs 24, 26, for example, have a thickness 28 of at least 0.5 millimeters.

[0027] Fig. 2 shows a further schematic plan view of the production of a battery arrangement 10. In particular, the cell connector 20 is provided. In the present exemplary embodiment, it is shown in particular that the cell connector 20 is designed in a frame-like manner and, for example, has a recess 30 in the region of the poles 14, 18. Such a frame-like cell connector 20 has an upper frame element and one or more lateral frame elements, which are essentially at an angle of 90 degrees thereto, as support and contact elements for a cell terminal. In the installed state, the frame-like cell connector 20 encloses a cell terminal in such a way that there is both an upper contact surface between the cell connector 20 and the cell terminal and a lateral contact surface between the cell connector 20 and the cell terminal.The upper contact surface positions the cell connector 20 in the z-direction and also serves as a stop when applying the cell connector 20. The lateral contact surface has the additional function of stabilizing and holding the cells in the x / y direction. Furthermore, Fig. 2 shows that, for example, the poles 14, 18 can have corresponding projections 32 onto which the cell connector 20 can in turn be placed.

[0028] The cell connector 20 is then applied to the two battery cells 12, 16, in particular to the terminals 14, 18, and then, for example, welded. A spacer 34, which can be designed as a tensioning mat, sealant, or adhesive, for example, can also be formed between the battery cells 12, 16. This spacer can be advantageously held together by the corresponding cell connector 20, particularly during corresponding cell growth.

[0029] Fig. 3 shows a further schematic plan view of different embodiments of the cell connector 20. On the left side, the frame-like cell connector 20 is shown, as already illustrated in Fig. 2. Here, the cell connector 20 is frame-like and, particularly in the area of ​​the poles, has the recess 30. In particular, the recess 30 is designed such that it encloses the first pole 14 and the second pole 18 with a single recess 30.

[0030] The middle part of Fig. 3 shows a further embodiment, wherein the frame-like structure encloses the first pole 14 with a first recess 36 and the second pole 18 with a second recess 38.

[0031] The right side of Fig. 3 shows a further cell connector 20, wherein it is shown in particular that the frame-like structure is S-shaped in a direction perpendicular to the U-shape and in turn has the first recess 36 and the second recess 38.

[0032] Overall, the figures show a so-called frame cell connector and a structural cell connector.

[0033] List of reference symbols

[0034] 10 Battery arrangement

[0035] 12 first battery cell

[0036] 14 first pole

[0037] 16 second battery cell

[0038] 18 second pole

[0039] 20 cell connectors

[0040] 22 Weld seam

[0041] 24 first leg

[0042] 26 second leg

[0043] 28 thickness

[0044] 30 recess

[0045] 32 lead

[0046] 34 spacers

[0047] 36 first recess

[0048] 38 second recess

Claims

Cell connector (20) for electrically contacting a first pole (14) of a first battery cell (12) with a second pole (18) of a second battery cell (16), wherein the cell connector (20) is designed to be welded to the poles (14, 18), characterized in that the cell connector (20) is substantially U-shaped and is supported on the first pole (14) with a first leg (24) of the U-shape and is supported on the second pole (18) with a second leg (26) of the U-shape, which is designed opposite the first leg (24). Cell connector (20) according to claim 1, characterized in that the cell connector (20) is arranged in the region of the first leg (24) and the second leg (26) with a weld (22) on the first pole (14) and the second pole (18).Cell connector (20) according to claim 1 or 2, characterized in that the cell connector (20) is frame-like and has a recess (30, 36, 38) in the region of the poles (14, 18). Cell connector (20) according to claim 3, characterized in that the frame-like structure encloses the first pole (14) and the second pole (18) in a single recess (30). Cell connector (20) according to claim 3, characterized in that. the frame-like structure encloses the first pole (14) with a first recess (36) and the second pole (18) with a second recess (38). Cell connector (20) according to claim 5, characterized in that the frame-like structure is S-shaped in a direction perpendicular to the U-shape. Cell connector (20) according to one of the preceding claims, characterized in that the legs (24, 26) have a thickness (28) of at least 0.5 mm. Cell connector (20) according to one of the preceding claims, characterized in that the weld (22) is designed as a fillet weld or as an I-seam. Cell connector (10) according to one of the preceding claims, characterized in that the battery cells (12, 16) are designed as hardcase cells.Battery arrangement (10) with a first battery cell (12) with a first pole (14) and with a second battery cell (16) with a second pole (18), wherein the first pole (14) is electrically connected to the second pole (18) by means of a cell connector (20) according to one of claims 1 to 9.

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