Cell connector, battery, motor vehicle and method for assembling a cell connector

Abstract

Cell connector (22) for electrically connecting a first pole terminal (16, 18) of a first battery cell (14) to at least one second pole terminal (16, 18) of at least one second battery cell (14) arranged in a first direction (x) next to the first battery cell (14), wherein the cell connector (22) comprises: - a first cell connector portion (22a) having a first side (24) providing a planar thermal coupling surface (24) for coupling to a cooling device (26); - a first contact tab (22b) for electrically conductive connection to the first pole terminal (16, 18); - at least one second contact tab (22b) for electrically conductive connection to the at least one second pole terminal (16, 18); and - at least one second cell connector section (22c), via which the first and second contact tabs (22b) are electrically conductively connected to the first cell connector section (22a); wherein the first and the second contact tab (22b) are arranged next to one another in the first direction (x) and are separated from one another by a recess (28), and wherein the first cell connector section (22a), the second cell connector section (22c), the first contact tab (22b) and the at least one second contact tab (22b) are formed in one piece, characterized in that - the cell connector (22) is U-shaped, - wherein the cell connector (22) has a first cell connector side and a second cell connector side opposite the first cell connector side, which are spaced from each other by a thickness of the cell connector (22), - wherein the first side (24) of the first cell connector section (22a) represents a part of the first cell connector side, - wherein the first contact tab (22b) has a first contact side for contacting the first pole terminal (16, 18), and the at least one second contact tab (22b) has a second contact side for contacting the at least one second pole terminal (16, 18), and - wherein the first and second contact sides are also part of the first cell connector side.

Description

[0001] The invention relates to a cell connector for electrically connecting a first pole terminal of a first battery cell to at least one second pole terminal of at least one second battery cell arranged adjacent to the first battery cell in a first direction. Furthermore, the invention also relates to a battery, a motor vehicle, and a method for assembling a cell connector.

[0002] Typical cell connectors used for electrically connecting cell poles, also referred to as pole terminals or cell terminals in the context of the present invention, are usually designed as busbars, especially in high-voltage batteries for motor vehicles. To be able to carry high currents, these must have a sufficiently large cross-section, which requires them to be designed as relatively rigid busbars. These are typically welded to the cell poles or cell terminals. However, if the busbars are too rigid, this leads to problems with thermal expansion, as this then leads to high mechanical stress forces in the system and possibly to damage.The position of the cell terminals can also change over the course of a battery's lifetime due to swelling effects, for example the cyclical expansion and contraction of the cells during charging and discharging, as well as the increasing expansion of the cells as they age. Cells are also subject to manufacturing tolerances which mean that the cell terminals, which are to be connected using cell connectors and are usually arranged next to one another in a line, are not at exactly the same height. This is not only caused by manufacturing tolerances in the manufacture of the cells, but also, for example, by arrangement tolerances in the arrangement of the cells on a housing base or similar. In this case, not just two terminals are to be connected to one another via the same busbar or cell connector, but possibly several.A rigid busbar is difficult or impossible to adapt to such manufacturing tolerances. In order to ensure tolerance compensation in as many spatial directions as possible, for example, to compensate for movement and to create options for adapting to manufacturing tolerances, some attempts have been made to design such busbars with a kind of corrugated shape. In other words, the cell connectors can have one or more corrugations between the individual contact areas for contacting the pole terminals, which are intended to ensure such tolerance compensation. Even then, tolerance compensation is only possible in one or at most two spatial directions.

[0003] For example, DE 10 2011 085 930 A1 describes a battery with several prismatic battery cells whose cell terminals can be connected to each other in pairs via cell connectors. The cell terminals are contacted by contact areas of a respective cell connector. Between two contact areas of a cell connector, the connector also has a wave structure.

[0004] Furthermore, WO 2019 / 086338 A1 describes a connection technology for battery terminal contacts. Here, a cell contact connector is connected to the terminal contacts of battery cells. Each battery cell has two cell terminals arranged on different, in particular opposite, sides of the battery cell. Furthermore, the terminal contacts of the battery cells are not connected directly to the cell contact connector, but rather via a current conductor consisting of a thin metal foil. First, such a metal foil is applied to the terminal contacts of the battery cell, then cell contact connectors, essentially designed as plates, are placed on top of the contact lugs. The cell contact connector has tapered recesses that taper toward the contact lugs located underneath, and the cell contact connector is then welded to the contact lugs along these recesses.

[0005] The additional element provided between the cell contacts and the cell connector, namely the contact tabs, makes the overall structure highly susceptible to failure. In particular, the robustness of the overall arrangement is significantly reduced compared to a direct arrangement of a cell connector at the pole contacts. However, a direct arrangement of such a cell connector plate directly at the poles would, in turn, leave no room for tolerance compensation.

[0006] JP 2019 - 9 220 A describes a terminal cooling device that can be connected to a battery cell via an S-shaped cell connector.

[0007] The object of the present invention is therefore to provide a cell connector, a battery, a motor vehicle and a method which make it possible to electrically interconnect battery cells and thereby provide the best possible tolerance compensation.

[0008] This object is achieved by a cell connector, a battery, a motor vehicle, and a method having the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.

[0009] A cell connector according to the invention for electrically connecting a first pole terminal of a first battery cell to at least one second pole terminal of at least one second battery cell arranged next to the first battery cell in a first direction has a first cell connector section having a first side providing a planar thermal coupling surface for connection to a cooling device. Furthermore, the cell connector comprises a first contact tab for electrically connecting to the first pole terminal, at least one second contact tab for electrically connecting to the at least one second pole terminal, and at least one second cell connector section, via which the first and second contact tabs are electrically connected to the first cell connector section.Furthermore, the first and the second contact tab are arranged next to one another in the first direction and separated from one another by a recess, and wherein the first cell connector section, the at least one second cell connector section, the first contact tab and the at least one second contact tab are formed in one piece.The cell connector is curved in a U-shape, wherein the cell connector has a first cell connector side and a second cell connector side opposite the first cell connector side, which are spaced from one another by a thickness of the cell connector, wherein the first side of the first cell connector section represents a part of the first cell connector side, wherein the first contact tab has a first contact side for contacting the first pole terminal, and the at least one second contact tab has a second contact side for contacting the at least one second pole terminal, and wherein the first and second contact sides are also part of the first cell connector side.

[0010] If the pole terminals of the battery cells to be contacted via the cell connector are arranged next to one another in the first direction, for example along a line, the cell connector, when it is connected to the relevant pole terminals as intended, is not designed as a continuous rail from pole terminal to pole terminal in the first direction, but instead is provided with cutouts or material gaps. The contact tabs, via which the individual pole terminals are to be contacted, thus protrude from one another at a distance from the rest of the cell connector, similar to fingers from a hand or like the teeth of a comb from the back of a comb. In this image, the first and second cell connector sections would correspond to the back of the comb, which connects the comb teeth to one another. The cell connector as a whole is not planar, but rather curved in a U-shape, as will be explained in more detail later.The recess or material gap arranged between the contact tabs advantageously enables the cell connector to achieve significantly better tolerance compensation. For example, the individual contact tabs can thus be adapted much more flexibly to possible height differences between the individual pole terminals. However, this cell connector advantageously enables significantly more flexible tolerance compensation not only in the direction of this height, which is also defined as the second direction in the context of the present invention, but also in the two other spatial directions perpendicular to it. A further particularly great advantage of the invention, however, is precisely that the first cell connector section can provide a thermal coupling surface for connection to a cooling device that is independent of the contact tabs.For cell connectors designed as busbars with a corrugated structure for tolerance compensation, such a connection was previously either not possible or was complex and not particularly efficient, as no planar coupling surface was available. In turn, such a connection requires tolerance compensation between such a cooling device and the cell connector, which is not possible with previous cell connectors that are directly connected to the cell poles. The cell connector according to the invention, on the other hand, makes it possible to connect to the cooling device not directly via the contact tabs that are to be contacted with the pole terminals, but via another section of the cell connector, which is referred to herein as the first cell connector section.This makes it easy to create a completely planar coupling surface, which can then be connected to a cooling device in a particularly simple manner. Another major advantage is that, for example, the contact tabs can be easily connected to the pole terminals by welding, without welding residues, which can lead to possible unevenness on the contact tabs, impairing the thermal connection to such a cooling device via the cell connector, since this thermal connection can advantageously be provided via a different coupling surface, namely that of the first cell connector section. This design of the cell connector ultimately enables tolerance compensation in all spatial directions in the battery system, as well as good thermal connection with optimal electrical cross-sections.

[0011] The division of the cell connector into the individual cell connector sections, in particular the first and second cell connector sections, as well as the contact tabs, serves merely to simplify the description and improve illustration. Nevertheless, the cell connector is formed in one piece, i.e., the cell connector sections and the contact tabs are manufactured as a single component, which provides the cell connector, and are not assembled from different, individual components to form the cell connector. For example, the cell connector sections and the contact tabs can be made of the same material, in particular with the same material thickness. The material thickness is preferably between 1 mm and 2 mm, preferably between 1 mm and 1.5 mm. The cell connector, and in particular none of the sections of the cell connector, should therefore be formed as a film.This advantageously makes it possible for the cell connector to be mechanically very robust, while at the same time allowing a high degree of flexibility with regard to tolerance compensation thanks to the recesses. For example, the cell connector can be made of aluminum. This enables particularly good heat dissipation from the cells, as aluminum has very high thermal conductivity. However, other metals or alloys can also be used to provide the cell connector. In the context of the present invention, a cell connector is understood to be an electrical contact element by means of which the pole terminals of individual battery cells can be electrically connected or interconnected with one another.One or more such cell connectors can be used to electrically interconnect several battery cells within, for example, a battery module, for example in a series and / or parallel circuit. The battery cells to be interconnected are preferably prismatic battery cells. These can be designed, for example, as lithium-ion cells. Each such battery cell, such as the first and second battery cell, has two cell poles, which are referred to here as pole terminals. These can also be referred to as cell terminals. One of these pole terminals represents a positive pole, the other a negative pole. Both pole terminals of the same battery cell are preferably arranged on the same side of the battery cell. This simplifies the interconnection and cable routing.Furthermore, the cell connector in the present case is preferably used in a battery designed as a high-voltage battery for a motor vehicle. Such a battery can comprise multi-cell battery cells, which can be combined to form battery modules, for example. In other words, such a battery can comprise a plurality of battery modules, each with a plurality of battery cells. Within such a battery module, the battery cells can be arranged next to one another, for example, along the first direction, preferably such that their largest sides face one another and their pole terminals are all arranged on the same side of such a battery module. The respective pole terminals of the respective battery cells arranged next to one another in the first direction should also be arranged next to one another in the first direction, in particular in pairs, for example along two lines running parallel to one another.A cell connector can be used to electrically contact at least two such pole terminals arranged side by side in the first direction along such a line, or even more than two pole terminals, such as four pole terminals. In this case, the cell connector would accordingly have four corresponding contact tabs, which are to be connected to the respective pole terminals to be contacted, for example by welding. An odd number of contact tabs is also conceivable. Such a battery module can accordingly have several cell connectors, which in particular can also comprise different numbers of contact tabs, in order to implement the cell interconnection within such a battery module.

[0012] In a very advantageous embodiment of the invention, the at least one second cell connector section is curved such that the first cell connector section is arranged above the first contact tab and the second contact tab with respect to a second direction perpendicular to the first, at a distance in the second direction from the first and at least one second contact tab, and in particular is arranged so as to cover the first contact tab, the at least one second contact tab, and the recess between the first and the at least one second contact tab. The first cell connector section is bent over in a U-shape relative to the contact tabs. This has the great advantage that it allows for particularly simple thermal coupling with a cooling device arranged above the battery cells. In addition, this enables a space-saving arrangement.The coupling surface for coupling to such a cooling device is thus also located directly above the pole terminals on the battery cells when properly arranged. This means that this coupling surface, or the first cell connector section, does not obstruct the cables typically routed above the cells between the pole terminals, and at the same time, the cell connector as a whole can be positioned as far as possible from the cell vents, which are typically located midway between the pole terminals. In the event of a cell defect, for example, very hot gas containing electrically conductive particles escapes from these vents. To prevent voltage breakdowns, it is advantageous to keep such gas away from the cell poles and also from the cell connectors, for example by means of suitable gas deflection mechanisms.This is easier to achieve the further such cell connectors are located from such cell degassing openings.

[0013] Nevertheless, it would have been conceivable for the cell connector to be designed such that the contact tabs, the second cell connector section, and the first cell connector section have a kind of stepped geometry, with the contact tabs then representing, for example, the tread surface of a lower step, the coupling surface of the first cell connector section representing the tread surface of a second, higher step, and the second cell connector section representing the corresponding connection between the tabs and the first cell connector section. However, such an arrangement would require more installation space, especially in a third direction perpendicular to the first and second directions.

[0014] The at least one second cell connector section defines the connection area between the contact tabs and the first cell connector section, which is preferably designed to be planar as a whole. Such a second cell connector section can be designed to be continuous in the first direction, so that this second cell connector section represents a certain connected area via which the individual tabs, in particular all tabs, of a cell connector are connected to the first cell connector section. Alternatively, a second cell connector section can also be provided for each tab, via which the corresponding tab is connected to the first cell connector section, of which there is only one per cell connector. Thus, the respective second cell connector sections can be seen as a continuation of the tabs via which the respective tabs are individually connected to the first cell connector section.The second variant is particularly advantageous because the recesses between the individual contact tabs extend to the first cell connector section. In other words, the respective second cell connector sections are then also separated from each other by such recesses. This increases the flexibility of the cell connector and further simplifies tolerance compensation. Furthermore, it provides improved thermal decoupling between the cells. This is particularly advantageous in the event of a cell runaway, as its temperature rise is transmitted to the neighboring cell at a slower rate.

[0015] According to the invention, the cell connector has a first cell connector side and a second cell connector side opposite the first cell connector side, which are spaced from each other by a thickness of the cell connector. As already described, these cell connector sides are not flat, and if the cell connector is curved as described above, they are also curved. Furthermore, the first side of the first cell connector section is part of the first cell connector side. Furthermore, the first contact tab has a first contact side for contacting the first pole terminal, and the at least one second contact tab has a second contact side for contacting the at least one second pole terminal. The first and second contact sides are also part of the first cell connector side.This is particularly advantageous if the first and second contact sides are each aligned at an angle to the thermal coupling surface of the first cell connector section that is less than 5° and preferably 0°. In other words, the first and second contact sides are preferably aligned parallel to the thermal coupling surface of the first cell connector section. The cell connector is therefore again bent or shaped in a U-shape, as already described above, so that the first cell connector section is located above the contact tabs. In this case, the contact sides of the contact tabs and the thermal coupling surface are provided by the same side of the cell connector, namely the first cell connector side.Due to the U-shaped bending of the cell connector, these surfaces, namely the thermal coupling surface and the contact sides of the contact tabs, are directed away from each other in the intended installation position, namely the contact sides downwards towards the pole terminals and the thermal coupling surface upwards towards the cooling device. With a stepped design of the cell connector, as described above, the contact sides of the contact tabs and the coupling surface are each arranged on different sides of the cell connector. In particular, for example, the coupling surface would then be arranged on the first cell connector side and the first and second contact sides of the contact tabs on the second cell connector side. This makes it possible to provide a top-side arrangement of a cooling device with a U-shaped structure without the cell connector.

[0016] Furthermore, the invention also relates to a battery for a motor vehicle comprising a cell connector according to the invention or one of its embodiments. The advantages described for the cell connector according to the invention and its embodiments apply equally to the battery according to the invention.

[0017] Furthermore, as already described at the beginning, the battery can be designed as a high-voltage battery, for example.

[0018] Furthermore, it is advantageous if the battery has the first battery cell with the first pole terminal and the at least one second battery cell with the second pole terminal, which are arranged next to one another in the first direction, such that the first and second pole terminals are arranged next to one another in the first direction, and wherein the cell connector is connected to the first and at least one second battery cell in such a way that the first contact tab is arranged in electrically conductive contact with the first pole terminal, in particular with the first contact side, and the at least one second contact tab is arranged in electrically conductive contact with the second pole terminal, in particular with the second contact side. For example, the arrangement can be achieved by welding the respective contact tabs to the corresponding pole terminals.This provides a particularly stable and at the same time cost-effective connection option.

[0019] In a further very advantageous embodiment of the invention, the battery has a cooling device, in particular a cooling plate through which a cooling medium can flow, wherein the cooling device has a cooling side facing the first and the at least one second battery cell, wherein the first and the at least one second battery cell are arranged with their respective first and second pole terminals facing the cooling side, and wherein the thermal coupling surface of the cell connector is at least indirectly connected to the cooling side, in particular wherein the thermal coupling surface is electrically insulated from the cooling side. As already described, it is particularly advantageous to connect the thermal coupling surface to a cooling device since, since it does not make direct contact with the pole terminals, it can be designed as a completely planar surface.This enables particularly simple and effective thermal coupling with a cooling device, which can be provided, for example, as a cooling plate through which a cooling medium can flow. Such a cooling plate can be arranged above the battery cells on a side facing the pole terminals of the battery cells. This planar coupling surface can create particularly good heat transfer to the cooling device. The cooling device or the described cooling plate can, for example, also be made of metallic material. In this case, it is advantageous to electrically insulate the cell connector from the cooling side. This can be achieved in a variety of ways, as explained in more detail below. However, it is also conceivable for the cooling device to be provided with a cooling side that is already electrically insulating.For example, the cooling side can also be provided as a type of plastic film or similar. However, providing it as a cooling plate, especially a metal cooling plate, allows for a significantly more robust and less error-prone design of the cooling device while simultaneously ensuring good heat transfer.

[0020] Accordingly, it represents an advantageous embodiment of the invention if a heat transfer layer, in particular a thermal pad, is arranged between the thermal coupling surface and the cooling side. Such a thermal pad can advantageously be used simultaneously for the electrical insulation of the thermal coupling surface from the cooling side. The thermal pad can therefore be provided, for example, in the form of a thin heat-conducting mat or the like, such as a silicone pad or the like. However, such a thermal pad can also be provided, for example, in the form of a ceramic plate or the like. In both cases, the thermal pad would also provide an electrically insulating property. If the heat transfer layer is designed, for example, as a pasty layer or adhesive layer instead, a separate electrical insulation is additionally provided to insulate the coupling surface from the cooling side.This can be provided as an additional electrically insulating layer between the cooling side and the coupling surface, or, for example, by an electrically insulating coating of the coupling surface or even the entire first cell connector section. If the thermal pad is also designed to be electrically insulating, one thermal pad can also be used for multiple cell connectors. In other words, a common, one-piece thermal pad can be arranged between the coupling surfaces of multiple cell connectors and the cooling side.

[0021] Furthermore, the invention also relates to a motor vehicle with a battery according to the invention or one of its embodiments. The motor vehicle according to the invention is preferably designed as an electric vehicle or hybrid vehicle. The battery preferably represents a traction battery of the motor vehicle.

[0022] Furthermore, the invention relates to a method for mounting a cell connector on a first pole terminal of a first battery cell and on at least one second pole terminal of at least one second battery cell arranged adjacent to the first battery cell in a first direction. The cell connector is designed as a cell connector according to the invention or one of its embodiments. Furthermore, the first contact tab is electrically conductively attached to the first pole terminal, and the second contact tab is electrically conductively attached to the second pole terminal.

[0023] The advantages described for the cell connector according to the invention and its configurations also apply to the method according to the invention in the same way.

[0024] The contact tabs can be attached to the respective pole terminals in a particularly simple manner by welding. Since they are located on the contact tabs, the welds are not in the area of ​​the connection point via which the cell connector can be connected to a cooling device. This connection point is provided, as described, via the thermal coupling surface provided by the first cell connector section.

[0025] It is furthermore very advantageous if, after the first and second contact tabs have been fastened to the first and second pole terminals, the first cell connector section is moved relative to the first and second contact tabs by deforming, in particular bending, the cell connector in such a way that, after the deforming, in particular the bending, the first and second contact tabs are each arranged at an angle to the thermal coupling surface that is less than 5° and preferably 0°. In other words, after the bending, the contact tabs should preferably be aligned substantially parallel to the first cell connector section. The initial geometry of the cell connector, for example before being fastened to the pole terminals, can be completely planar, for example.In general, it is advantageous if the cell connector is prepared before the first and second contact tabs are attached to the first and second pole terminals such that the first and second contact tabs are each aligned at an angle to the thermal coupling surface of the first cell connector section that is at least 90°, preferably 180°. This makes welding the tabs to the pole terminals particularly easy. Only subsequently can the first cell connector section be bent over the contact tabs, thus enabling a particularly space-efficient connection to a cooling device arranged above the cells.

[0026] The invention also includes further developments of the method according to the invention that have features already described in connection with the further developments of the cell connector according to the invention and the battery according to the invention. For this reason, the corresponding further developments of the method according to the invention are not described again here.

[0027] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.

[0028] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0029] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 a schematic representation of a battery with a battery module with several battery cells connected via cell connectors according to an embodiment of the invention; Fig. 2 a schematic representation of a part of the battery from Fig. 1 with cell connectors connected to a cooling device via a thermal pad according to a further embodiment of the invention; Fig. 3 a schematic representation of a battery with several battery cells, the pole terminals of which are connected to one another via cell connectors in a state during the bending of a part of the respective cell connectors according to an embodiment of the invention; and Fig. 4 a schematic representation of the battery from Fig. 3 after bending the part of the cell connectors in the final state.

[0030] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that can be considered independently of one another, each of which also develops the invention independently of one another. Therefore, the disclosure is intended to encompass combinations of the features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0031] In the figures, the same reference symbols designate elements with the same function.

[0032] Fig. 1 shows a schematic representation of a battery 10 with an exemplary battery module 12 according to an embodiment of the invention. The battery module 12 has a plurality of battery cells 14. These are designed as prismatic battery cells 14. Furthermore, these are arranged next to one another in a first direction, namely the x-direction shown here. A respective battery cell has two cell poles on its respective upper side 14a, which are referred to herein as pole terminals 16, 18. For example, the pole terminals designated 16 represent positive poles and the pole terminals designated 18 represent negative poles, or vice versa. A respective cell has exactly one positive pole 16 and exactly one negative pole 18. The cells 14 are aligned such that their pole terminals 16, 18 all point in the same direction.In the center of each upper side 14a on each battery cell 14 there is also a releasable vent 20, from which hot gases can escape in the event of thermal runaway of a battery cell 14. The cells 14 are now electrically interconnected via cell connectors 22. As a result, two or more cell terminals 16, 18, which are arranged next to one another in the first direction, are electrically contacted via such a cell connector 22. In the present example, four such cell connectors 22 are shown. Two of these four cell connectors 22 contact exactly two pole terminals 16, 18 with one another, and the other two cell connectors 22 contact exactly four pole terminals 16, 18 with one another. These cell connectors 22 can, for example, be designed as thin, bent aluminum plates, as shown. For better description, such a cell connector 22 can be divided into several areas.Each cell connector 22 has a first cell connector section 22a. This provides a thermal coupling surface 24 that is completely planar, i.e., flat, and is therefore particularly well suited for connection to a cooling device, such as a cooling plate 26 (see ). Fig. 2), above the battery module 12. The term "above" refers to a second direction, namely the z-direction shown here. A third direction is defined accordingly as the y-direction shown here. The contacting of the individual pole terminals 16, 18 is effected via respective contact tabs 22b of the respective cell connectors 22. Of these, Fig. 1, only a few are provided with a reference symbol by way of example. These contact tabs 22b are advantageously spatially separated from one another in the x-direction by corresponding recesses in the cell connectors 22. The recesses are designated 28 here and represent material gaps between the corresponding contact tabs 22b in the x-direction. Furthermore, a respective cell connector 22 also comprises at least one second cell connector section 22c. In the present example, each cell connector 22 comprises just as many second cell connector sections 22c as contact tabs 22b. These second cell connector sections 22c merely designate the connection area between the contact tabs 22b and the first cell connector section 22a. Here, too, only a few of these cell connector sections 22c are provided with a reference symbol. This advantageous design of the cell connectors 22 enables tolerance compensation in three spatial directions, as is possible by Fig. 2. Due to the respective recesses 28 and the curved structure, the geometry of such a cell connector 22 can provide tolerance compensation in both the x-, y-, and z-directions. Fig. 2 also schematically illustrates the connection of the thermal coupling surfaces 24 to a cooling device 26. In this example, the connection is made via an additional electrically insulating thermal pad 30. This allows heat dissipation directly from the cell poles 16, 18 to the cooling device 26 to be provided in a particularly simple and efficient manner.

[0033] Fig. 3 and Fig. 4 also show a schematic representation of a battery 10 with several battery cells 14 during the assembly process for arranging the cell connectors 22 on the respective cell terminals 16, 18. Fig. 3 illustrates, in particular, the connection step for attaching the contact tabs 22b to the corresponding pole terminals 16, 18. These are connected to one another in particular by welding, for example laser welding. The welding points are designated 32 in the present case. However, the cell connector 22 in question is not yet bent or provided in a U-shape in the initial state, but rather, for example, planar, so that the contact tabs 22b and the first cell connector section 22a are located, for example, in one plane. This significantly simplifies the welding process for connecting the contact tabs 22b to the poles 16, 18. Only after the attachment of the contact tabs 22b to the poles 16, 18 does a forming, in particular bending, of the first cell connector section 22a take place, which in Fig. 3 is illustrated by the arrows 34.

[0034] After bending 34, the respective cell connectors 22 are in their final end position, as shown in Fig. 4. Subsequently, a simple connection to a cooling device 26, in particular via a thermal pad 30, can be made, as in Fig. 2 illustrated.

[0035] Overall, the examples demonstrate how the invention can provide a cell connector with tolerance compensation, which particularly advantageously enables tolerance compensation and movement compensation, for example, cell swelling, in all spatial directions at the cell terminals. Due to the subsequent forming of the cell connectors during the production process, a homogeneous connection to a cover or the cooling side can be ensured.

Claims

[1] Cell connector (22) for electrically connecting a first pole terminal (16, 18) of a first battery cell (14) to at least one second pole terminal (16, 18) of at least one second battery cell (14) arranged in a first direction (x) next to the first battery cell (14), wherein the cell connector (22) comprises: - a first cell connector portion (22a) having a first side (24) providing a planar thermal coupling surface (24) for coupling to a cooling device (26); - a first contact tab (22b) for electrically conductive connection to the first pole terminal (16, 18); - at least one second contact tab (22b) for electrically conductive connection to the at least one second pole terminal (16, 18); and - at least one second cell connector section (22c), via which the first and second contact tabs (22b) are electrically conductively connected to the first cell connector section (22a); wherein the first and the second contact tab (22b) are arranged next to one another in the first direction (x) and are separated from one another by a recess (28), and wherein the first cell connector section (22a), the second cell connector section (22c), the first contact tab (22b) and the at least one second contact tab (22b) are formed in one piece, characterized by , that - the cell connector (22) is U-shaped, - wherein the cell connector (22) has a first cell connector side and a second cell connector side opposite the first cell connector side, which are spaced from each other by a thickness of the cell connector (22), - wherein the first side (24) of the first cell connector section (22a) represents a part of the first cell connector side, - wherein the first contact tab (22b) has a first contact side for contacting the first pole terminal (16, 18), and the at least one second contact tab (22b) has a second contact side for contacting the at least one second pole terminal (16, 18), and - wherein the first and second contact sides are also part of the first cell connector side. [2] Cell connector (22) according to claim 1, characterized byin that the at least one second cell connector section (22c) is curved such that the first cell connector section (22a) is arranged above the first contact tab (22b) and the second contact tab (22b) with respect to a second direction (z) perpendicular to the first, at a distance in the second direction (z) from the first and at least one second contact tab (22b), and in particular the first contact tab (22b), the at least one second contact tab (22b) and the recess (28) between the first and the at least one second contact tab (22b) is arranged so as to cover. [3] Cell connector (22) according to one of the preceding claims, characterized by that the first and second contact sides are each aligned at an angle to the thermal coupling surface (24) of the first cell connector section (22a) which is less than 5°, and preferably 0°. [4] Battery (10) for a motor vehicle with a cell connector (22) according to one of the preceding claims. [5] Battery (10) according to claim 4, characterized by in that the battery (10) has the first battery cell (14) with the first pole terminal (16, 18) and the at least one second battery cell (14) with the second pole terminal (16, 18), which are arranged next to one another in the first direction (x), so that the first and the second pole terminal (16, 18) are arranged next to one another in the first direction (x), wherein the cell connector (22) is connected to the first and at least one second battery cell (14) in such a way that the first contact tab (22b) is arranged in electrically conductive contact with the first pole terminal (16, 18), and the at least one second contact tab (22b) is arranged in electrically conductive contact with the second pole terminal (16, 18). [6] Battery (10) according to one of claims 4 or 5, characterized byin that the battery (10) has a cooling device (26), in particular a cooling plate (26) through which a cooling medium can flow, which has a cooling side facing the first and the at least one second battery cell (14), wherein the first and the at least one second battery cell (14) are arranged with their respective first and second pole terminals (16, 18) facing the cooling side, wherein the thermal coupling surface (24) of the cell connector (22) is at least indirectly connected to the cooling side, in particular wherein the thermal coupling surface (24) is electrically insulated from the cooling side. [7] Battery (10) according to one of claims 4 to 6, characterized by that a heat transfer layer (30), in particular a thermal pad (30), is arranged between the thermal coupling surface (24) and the cooling side. [8] Motor vehicle with a battery (10) according to one of claims 4 to 7. [9] Method for mounting a cell connector (22) on a first pole terminal (16, 18) of a first battery cell (14) and at least one second pole terminal (16, 18) of at least one second battery cell (14) arranged in a first direction (x) next to the first battery cell (14), characterized by that the cell connector (22) represents a cell connector (22) according to one of claims 1 to 3, and wherein the first contact tab (22b) is electrically conductively attached to the first pole terminal (16, 18) and the second contact tab (22b) is attached to the second pole terminal (16, 18). [10] Method according to claim 9, characterized byin that the first cell connector section (22a), after the first and second contact tabs (22b) have been fastened to the first and second pole terminals (16, 18), is moved relative to the first and second contact tabs (22b) by bending the cell connector (22) in such a way that after the bending, the first and second contact tabs (22b) are each at an angle to the thermal coupling surface (24) that is less than 5°, and preferably 0°, in particular wherein the cell connector (22) is provided before the first and second contact tabs (22b) are fastened to the first and second pole terminals (16, 18) in such a way that the first and second contact tabs (22b) are each aligned at an angle to the thermal coupling surface (24) of the first cell connector section (22a) that is at least 90°, preferably 180°.

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