Cell connector and method for contacting at least two galvanic cells

Description

[0001] The invention relates to a cell connector for interconnecting at least two conductors and / or strands made of at least one substantially strip-shaped element and to a method for contacting at least two galvanic cells by means of at least one such cell connector.

[0002] A galvanic cell, also known as a battery cell, is a device for converting chemical energy into electrical energy. Such a galvanic cell can also be used to supply mobile devices with electrical energy. A wide variety of designs of galvanic cells and battery modules consisting of a large number of interconnected galvanic cells are known from the general state of the art. Individual galvanic cells can be connected in series to increase the voltage output by the galvanic cells. Several individual galvanic cells or those connected in series can also be connected in parallel to increase the capacity of a battery module consisting of several galvanic cells. The electrical interconnection of individual galvanic cells is achieved via corresponding contact elements. In particular, in the case of so-called pouch cells, aluminum or copper elements are used for this purpose.Copper arresters are used.

[0003] To ensure a robust connection, the arresters are welded. Such a connection requires a minimum cross-sectional area, as comparatively high currents are transmitted via the arresters and thus also via the corresponding connection point. If the cross-section is too small, the connection point can heat up so much that individual components of a pouch cell and / or a battery module are at risk of being damaged or destroyed. To ensure a high level of process reliability when creating the welded connection between multiple arresters, a number of challenges must be overcome. For example, it is necessary for the two arresters to be connected to rest on one another over as large a surface area as possible, since if the two arresters are not properly connected, gaps may remain between the arresters after the arresters have been welded.For example, the arresters to be connected are often pressed together using spring-loaded clamping fingers, clamping frames, or similar devices before welding to compensate for any gaps between the arresters. A cell frame is often used as a counter-support. However, gaps can form between the arresters to be connected due to tolerances in bending the arresters or stacking the galvanic cells, slippage of the galvanic cells during transport, or incorrectly adjusted clamping force in a clamping device. Furthermore, the clamping force cannot be set to any desired level, as the maximum clamping force is limited by the stability or strength of the cell frame.

[0004] Typically, the first conductor of a welded conductor pair comprises aluminum or an aluminum alloy, and the second conductor comprises copper or a copper alloy. This requires a strong bond between two different materials. Selecting and maintaining correct welding parameters is therefore particularly challenging. There is a high risk, for example, of welding through the conductors into the cell frame. When multiple galvanic cells are connected in parallel, multiple layers of conductors are welded together, which can lead to cumulative tolerances and stacking errors.

[0005] Typically, pouch cell arresters are joined using laser welding. Other welding methods, such as ultrasonic welding, can also be used, but these have specific disadvantages. Ultrasonic welding requires access to the workpieces to be welded from both sides and requires a large amount of space for clamping the workpieces. Ultrasonic welding systems are therefore comparatively large. Furthermore, the electrodes used for welding wear out. Furthermore, the arresters to be joined can stick to the welding electrodes.

[0006] It is also known to connect several galvanic cells in parallel using a so-called cell connector. The cell connector is, for example, a metallic strip-shaped element. If the galvanic cells to be connected have a height offset from one another, the cell connector lies at an angle on the arresters to be connected, resulting in only point-like or linear contact between the cell connector and the arresters. This leads to a reduction in the cross-section of an electrical contact between the galvanic cells to be connected. To compensate for such a height offset, such a cell connector can be bent along at least one section. However, this poses the problem that the cell connector must be precisely positioned in order to produce a weld seam of sufficient quality.The more cells that need to be connected with a cell connector, the more serious the problems resulting from the height offset can become. For individual cells, the height offset can be so large that an air gap occurs between the arrester and the cell connector. It is also known to provide openings in the cell connector for the arresters to pass through. However, this requires the arresters to be threaded through the cell connector and leads to mechanical stress on the arresters, which can damage them. There is also the risk that laser radiation will strike the galvanic cells to be contacted. To avoid this, stricter requirements are being placed on the positioning of the galvanic cells to be connected, or the arresters and cell connectors, in a laser welding machine.

[0007] Furthermore, US 6,641,027 B2 discloses a method for contacting electrical connections with battery arresters. In many electronic devices, a battery is connected to the electrical circuits of the electronic device by welding or soldering. However, due to the limited space available within the electronic device, accessibility to the corresponding welding or soldering points is poor. The method disclosed in the document describes the molding of metallic strips onto arresters of a battery cell, which can then be more easily contacted with other current-carrying components or electrical connections due to their larger surface area and better accessibility. For this purpose, a metallic strip is placed flat on each arrester and bent around it so that the metallic strip surrounds the arrester as extensively as possible.The resulting layered structure, consisting of a conductor and a metallic strip, is then clamped in an ultrasonic welding system, and the individual layers are joined by ultrasonic welding. The welded layered structure is then cut to size.

[0008] Furthermore, US 2002 / 146620 A1 discloses a method for connecting cell arresters in a multilayer cell. The cell arresters are placed on top of each other, pressed together, and welded together. The welded stack of cell arresters is then folded in to save space.

[0009] Furthermore, US 2009 / 0246620 A1 discloses a lithium battery. The battery is designed as a pouch cell. Cell conductors are supported on two plates. The plates are curved to extend along the circumference of the pouch cell on two sides each.

[0010] Furthermore, US 2010 / 0173193 A1 discloses a lithium-ion secondary battery in pouch cell format. The secondary battery comprises two cell conductors, one of which is designed as a variable cell conductor. To connect the variable cell conductor to an electrode conductor of the secondary battery, one of the conductors can be bent into a U-shape so that a section of the other cell conductor can be held by the bent section.

[0011] Furthermore, US 2012 / 0070720 A1 discloses a battery and a method for ultrasonic welding of the battery. A cell conductor is connected to several electrode conductors by ultrasonic welding. The cross-section of the cell conductor increases from the welding point toward an external conductor.

[0012] Furthermore, US 2020 / 373548 A1 discloses a rectangular secondary battery. An external terminal is electrically connected to a common terminal. Several common arresters of several galvanic cells are electrically connected to the common terminal via a clamping element. The common arresters each have a curved section that can be clamped to the clamping element.

[0013] In addition, US 2020 / 0373584 A1 discloses battery interconnects and metallized film components in energy storage devices with internal fuses. A conductor is connected to a current collector of a galvanic cell. The current collector has a multilayer structure. Several current collectors are connected to the conductor via a welded connection. Such a package can be crimped using a reinforcing band or a clamp.

[0014] The present invention is based on the object of providing a cell connector for connecting at least two arresters and / or stranded wires to one another, with the aid of which the arresters or stranded wires to be connected are reliably aligned with one another, so that a particularly reliable welded connection between the arresters and / or stranded wires to be connected can be established with reduced effort. A further object of the present invention is to provide a method for contacting at least two galvanic cells using at least one such cell connector.

[0015] According to the invention, this object is achieved by a cell connector having the features of claim 1 and a method for contacting at least two galvanic cells having the features of claim 10. Advantageous embodiments and further developments emerge from the dependent claims.

[0016] A cell connector for interconnecting at least two arresters and / or strands comprising at least one substantially strip-shaped element has at least five sections arranged one behind the other in a longitudinal direction on the strip-shaped element. According to the invention, a first section forms a first half of a closure element, a second section forms a first clamping surface, a third section forms a deflection element, a fourth section forms a second clamping surface, and a fifth section forms a second half of the closure element. The third section is configured to enable the first and second sections to be folded relative to the fourth and fifth sections about a folding axis extending through the third section in a width direction orthogonal to the longitudinal direction.As a result, the strip-shaped element can be transferred into a folded state, in which at least one section of the first and second clamping surfaces lie opposite one another substantially in a thickness direction orthogonal to the longitudinal and width directions, thus forming a receptacle for the conductors and / or strands. The first and fifth sections can be connected to one another in the folded state of the strip-shaped element in order to fix the at least one strip-shaped element in the folded state.

[0017] With the aid of the cell connector according to the invention, particularly reliable alignment and fixing of the connecting conductors and / or strands is possible, which increases process reliability in a welding process for the materially bonded connection of the conductors and / or strands following the alignment. By folding together the at least one essentially strip-shaped element, referred to below as closing, the conductors and / or strands to be connected are pressed together, thereby compensating for stacking tolerances. If the at least one essentially strip-shaped element is closed, the conductors and / or strands to be connected are fixed and can no longer move relative to one another and thus detach from one another, even during transport to a welding station.When folded together, the at least one substantially strip-shaped element completely surrounds the receptacle in a circumferential direction. Thus, the fourth section or the second clamping surface forms a substrate or base for a laser welding process, making it more difficult to weld through the arresters and / or strands. The second section or the first clamping surface is arranged between the arresters and / or strands to be connected and a laser light source during a laser welding process, thus representing a material depot. This makes it possible to also melt the second section and integrate it into a material-to-material connection between the arresters and / or strands to be connected. This makes it possible to fill potential gaps. By selecting the appropriate material, the resulting welded joint can also be alloyed in a targeted manner.

[0018] In addition, the manufacturing effort required to contact multiple galvanic cells via the arresters can be reduced by using the cell connector according to the invention. This eliminates the need for complex adjustment of clamping brackets used to press the arresters together. With the help of the cell connector according to the invention, the arresters to be connected are pressed together particularly easily and reliably. This also allows different cell geometries to be flexibly connected to one another, since it is not necessary to modify the clamping technology used to press the arresters together. Accordingly, a type- or variant-flexible laser cabin is conceivable. This also reduces the programming effort required for the laser welding machine used to weld the arresters and / or strands to be connected. Furthermore, resulting weld seams can be more easily inspected, as they are no longer concealed by complex clamping technology.Furthermore, the cell connector according to the invention can be manufactured particularly easily and cost-effectively. For example, the cell connector is a simple bent sheet metal stamping. According to an advantageous embodiment, the cell connector according to the invention can also be cut from a sheet metal.

[0019] An advantageous development of the cell connector provides that the third section comprises at least one perforation, a hinge and / or an elastic material and / or is profiled at least in sections. The third section serves to enable individual sections of the cell connector to be deflected or bent in order to close the at least one essentially strip-shaped element or to bring it into the folded state. By introducing perforations into the third section, the flexural rigidity of the third section is reduced, as a result of which the essentially strip-shaped element can be bent particularly easily about the folding axis. The perforations can be designed in any desired manner. For example, they are one or more rectangular cutouts. However, the cutouts can also have any desired shape. For example, the cutouts orPerforations can also be oval, circular or in the shape of any desired polygon. In addition to or alternatively to the perforations, a hinge can also be integrated into the third section or form it. By means of a two-part hinge, it is possible to form the cell connector by connecting at least two essentially strip-shaped elements to one another. A first essentially strip-shaped element comprises the first and second sections and a second essentially strip-shaped element comprises the fourth and fifth sections. For example, the third section can also have a film hinge or be formed by it. Additionally or alternatively, the third section can also comprise an elastic material. For example, the third section can comprise rubber, for example an elastomer.An elastic material can be bent, stretched, or compressed particularly easily, whereby the at least one essentially strip-shaped element can be converted into the folded state particularly easily. A joint can also be integrated into the third section or form it. Additionally or alternatively, the third section can also be profiled. For example, the third section can be designed like an accordion or a casing for a joint of an articulated bus. This further simplifies bending or deflecting the individual sections of the at least one strip-shaped element. The profiling can be designed as desired, in particular can have any orientation in the third section. For example, the profiling preferably runs in the longitudinal direction. This ensures a certain minimum flexural rigidity in the width direction and reduces flexural rigidity around the folding axis.This allows the at least one substantially strip-shaped element to be particularly easily folded into the collapsed state, preventing or reducing tilting of the opposing sections. This ensures that, in the collapsed state, the second and fourth sections or the first and second clamping surfaces remain aligned as parallel to each other as possible, which increases the reliability of the pressing action of the conductors and / or strands to be connected.

[0020] According to a further advantageous embodiment of the cell connector, the first section and the fifth section are configured to form a positive connection, in particular by bending, flanging, rolling or clinching at least one of the sections; and / or the first section and the fifth section are configured to form a frictional connection and / or material connection, in particular by riveting, screwing, welding and / or gluing the sections. This allows the first and the fifth section to be fixed particularly reliably. An unintentional opening of the at least one essentially strip-shaped element from the folded state can thus be reliably prevented. In particular, the first and the fifth section have a correspondingly matching geometry so that they can be connected particularly easily.For example, the first section can be designed as a tab and the fifth section as a pocket to accommodate the tab. The tab can then be bent into the pocket, making it particularly easy to connect the first and fifth sections. This connection can then be secured, for example, by crimping. It is also possible to create a positive connection between the first and fifth sections, for example by soldering the two sections. In general, it is also conceivable to fix at least one essentially strip-shaped element in the folded state by slipping it over or otherwise fastening an additional clamping device. For example, a comparatively tight rubber band can be slipped over an essentially strip-shaped element in the folded state. A shrink tube, for example, can also be used for this purpose.

[0021] A further advantageous embodiment of the cell connector further provides that the second section has a recess which runs completely through the second section in the thickness direction to form a welding window, in particular a substantially rectangular recess, wherein a longer edge of the recess runs in the longitudinal direction. By introducing the recess into the second section or the first clamping surface, direct access of a laser of a laser welding machine to the arresters and / or strands to be connected is made possible. This eliminates the need to weld through the second section or the first clamping surface. This reduces thermal stress on the elements to be connected. Furthermore, higher welding speeds and / or lower laser power are possible. In addition, a resulting weld seam can be visually inspected more easily. By creating the recess orthe welding window in particular runs essentially in the longitudinal direction, a long edge of the recess coincides with a preferably selected welding seam direction. It is also conceivable to design the recess in an interrupted manner so that individual sections of a resulting weld seam can be alloyed with a material of the essentially strip-shaped element made by melting it. This allows the conductivity and / or mechanical strength of the weld seam to be adjusted even more precisely. Analogous to the perforations made in the third section, the recess for forming the welding window can also be made in the second section, for example by punching out the recess. However, it is also possible to cut the recess out of the second section, for example by means of a laser beam or water jet.

[0022] According to a further advantageous embodiment of the cell connector, at least two strip-shaped elements arranged parallel to one another in the longitudinal direction are connected via at least one web extending from the second and / or fourth section in the width direction away from the strip-shaped element and running in the longitudinal direction. By means of such a cell connector, individual galvanic cells and / or cells shaded in series can be connected in parallel particularly easily and reliably. The web can have any desired shape. In particular, it extends in the longitudinal direction over the entire length of the second and / or fourth section. As a result, a cross-section of the web viewed in the width direction is increased, whereby thermal loading of the web due to comparatively high currents can be reduced.In particular, the web has the same material thickness as the other sections of the essentially strip-shaped elements, viewed in the thickness direction. This makes it particularly easy to manufacture a corresponding cell connector. This can also be punched or cut from a sheet metal.

[0023] A further advantageous embodiment of the cell connector further provides that the web has at least one perforation, wherein in particular the web has a smaller thickness in the thickness direction than the substantially strip-shaped element and / or the web is corrugated in the width direction. This makes it even easier to compensate for a height offset of galvanic cells arranged next to one another and connected by the cell connector according to the invention. Due to the perforations introduced into the web, the individual substantially strip-shaped elements can be easily displaced relative to one another in the thickness direction. A corresponding stiffness of the web can be reduced even further by reducing the thickness of the web in the thickness direction.A cross-sectional shape of the web viewed in the longitudinal direction can also have a corresponding contour, for example the cross-section can be corrugated in order to be able to more easily compensate for a height offset between individual, essentially strip-shaped elements of a cell connector in the thickness direction.

[0024] According to a further advantageous embodiment of the cell connector, at least one substantially strip-shaped element has a connecting flange running in the longitudinal direction and extending in the width direction away from the second and / or fourth section for contacting the substantially strip-shaped element with a current-carrying component superimposed on the substantially strip-shaped element. With the aid of the connecting flange, easy contact of the cell connector according to the invention, for example with a current contact rail, is possible. This also makes it particularly easy to interconnect several battery modules or cell blocks. The connecting flange can, analogous to the first or fifth section, have a shape specially adapted to certain installation situations or geometric situations.

[0025] For example, one or more through holes can be introduced into the connecting flange to enable the connecting flange to be screwed to, for example, the current contact rail. Current can flow through a screw passed through a through hole. In general, it is conceivable that any form-fitting, force-fitting, and / or material-locking connection can be established between at least one connecting flange and at least one higher-level current-carrying component. For example, the connecting flange can also be welded or riveted to the current contact rail. Advantageously, a connecting flange is encompassed by a substantially strip-shaped element located at one edge of a cell connector comprising several such elements.

[0026] A further advantageous embodiment of the cell connector further provides that, in order to increase the contact pressure acting in the thickness direction of the first and second clamping surfaces on the conductors and / or strands arranged in the receptacle when the at least one substantially strip-shaped element is folded together, the second section is curved at least in sections in the thickness direction and / or at least one half of the closure element has a contour extending in the thickness direction when the closure element is connected. Preferably, the conductors and / or strands to be connected are pressed against one another with a comparatively high contact pressure in order to fix them particularly reliably to one another. By curving the second section, this contact pressure is increased by a spring effect of the second section resulting from the curvature.The entire second section can be curved or at least have individual curves in certain sections. The individual curves can have the same or a different radius of curvature. In addition to or as an alternative to the curvature of the second section, one or both halves of the closure element can also have contours running in the thickness direction. These can have any cross-sectional shape. For example, they can be conical or pyramid-shaped tips. At least one half of the closure element can also be corrugated in sections in the thickness direction. The contouring makes it necessary to fold the first and second sections further around the folding axis until the first and fifth sections can be closed.As a result, a distance between the first and second clamping surfaces in the thickness direction is reduced, whereby a contact force on the arresters and / or strands located in the receptacle is increased.

[0027] Preferably, the at least one substantially strip-shaped element is formed entirely from a conductive material, in particular a metal and / or a metal alloy, and preferably from a metal sheet, or the at least one substantially strip-shaped element is formed at least partially from a conductive material, in particular a metal or a metal alloy, and preferably from a metal sheet, and at least partially from a current-insulating material, wherein the insulating material advantageously forms at least the fourth section. If the at least one substantially strip-shaped element comprises a conductive material, a current flow between a plurality of arresters and / or strands to be connected can also run at least partially through the at least one substantially strip-shaped element.Thus, with the help of at least two strip-shaped elements, a parallel connection of several galvanic cells can be implemented particularly easily. If the at least one essentially strip-shaped element comprises metal or a metal alloy, the second section can also be welded on and integrated into a material-to-material welded joint of the conductors and / or strands to be connected.

[0028] It is also conceivable that, in a cell connector comprising at least two substantially strip-shaped elements, a first substantially strip-shaped element comprises the first and second sections and a second substantially strip-shaped element comprises the fourth and fifth sections, wherein the first substantially strip-shaped element is made entirely of a metal alloy and the second substantially strip-shaped element is made of the insulating material. If the fourth section, i.e. the second clamping surface, comprises the insulating material, this can function as a bath support. If, on the other hand, the fourth section also comprises metal or a metal alloy, welding can also be carried out into it, which ensures reliable contacting of the arresters and / or strands.

[0029] In general, it is also conceivable that the entire cell connector is made of the insulating material.

[0030] In a method for contacting at least two galvanic cells by means of at least one cell connector as described above, at least the following method steps are carried out according to the invention: Aligning the conductors and / or strands to be connected with each other; arranging the cell connector relative to the conductors and / or strands such that the fourth section is supported, at least in sections, with a side facing away from the receptacle on a casing of at least one galvanic cell and / or at least one conductor and / or at least one strand rests on a side of the fourth section facing the receptacle; folding the first and second sections by means of the folding axis running through the third section in the width direction in order to bring the strip-shaped element into the folded state; closing the closure element; welding the conductors and / or strands to be connected or welding at least one section of the cell connector to the conductors and / or strands to be connected, in particular by means of at least one weld seam running in the longitudinal direction, wherein laser welding is preferably used as the welding method.

[0031] In this case, the arresters and / or strands to be connected are aligned with one another in such a way that they touch or lie on top of one another over as large a surface area as possible in order to enable low-resistance contact between the galvanic cells to be connected. The arresters and / or strands to be connected are fixed in this state with the aid of the cell connector according to the invention. For this purpose, the cell connector according to the invention is guided around the arresters and / or strands to be connected and closed like a clamp. Optionally, the cell connector according to the invention can be supported on a casing of at least one galvanic cell or of a battery module and / or battery housing comprising the galvanic cell. Preferably, at least one arrester and / or at least one strand lies flat on at least one of the clamping surfaces. This allows a contact force to be applied particularly evenly to the arresters and / or strands to be connected.The closure element is closed using any form fit, friction fit, and / or material fit. For example, individual sections of one half of the closure element, such as a tab or a projection, can be folded over, flanged, rolled up, or the like, in order to be inserted or received, for example, by an opening or receptacle in the corresponding mating half of the closure element. A closed closure element can be additionally secured by riveting, screwing, welding, soldering, gluing, or the like. The galvanic cells to be contacted can then be safely transported without the conductors and / or strands to be connected being able to shift or slip during transport, since the contact force exerted on the conductors and / or strands by the cell connector according to the invention prevents this.The conductors and / or strands to be connected are then welded. Any welding method, preferably laser welding, can be used for this purpose. Due to the compression of the conductors and / or strands by the cell connector according to the invention, a particularly reliable welded connection can be created.

[0032] Further advantageous embodiments of the cell connector according to the invention and of the method according to the invention also emerge from the exemplary embodiments which are described in more detail below with reference to the figures.

[0033] Showing: Fig. 1 shows a schematic diagram of four known variants for interconnecting several pouch cells; Fig. 2 shows a top view and a side view of a cell connector according to the invention as well as two detailed views of a third section of the cell connector according to the invention; Fig. 3 shows a top view of a cell connector according to the invention according to an alternative embodiment; Fig. 4 shows a top view of a cell connector according to the invention with several essentially strip-shaped elements; Fig. 5 shows a top view and a side view of a cell connector according to the invention according to an alternative embodiment; Fig. 6 shows a detailed view of a Figure 5 shown section BB; Fig. 7 a plan view of a cell connector according to the invention with several substantially strip-shaped elements according to an alternative embodiment; Fig. 8 a detailed view of a Figure 7shown section CC; Fig. 9 a plan view of a cell connector according to the invention according to an alternative embodiment with a connecting flange; Fig. 10 a schematic diagram of a method according to the invention for contacting at least two galvanic cells; Fig. 11 a detailed view of a Figure 10 shown section DD; and Fig. 12 a side view of a laser welding process for contacting two electrical cables by means of the cell connector according to the invention.

[0034] Figure 1 serves to illustrate a problem when interconnecting several so-called pouch cells 19 in the prior art. Figure 1a ) a problem when interconnecting pouch cells 19 in series and Figure 1b) a problem when interconnecting several pouch cells 19 in parallel. In order to connect at least two pouch cells 19 in series, arresters 2, usually made of copper or aluminum, leading out of the pouch cells 19 are welded together. For this purpose, the arresters 2 to be connected advantageously touch each other over as long a distance as possible. Due to bending errors in the alignment of the arresters 2 to be connected to each other and / or component tolerances, the arresters 2 to be connected do not run parallel but diagonally to each other, as a result of which they do not lie flat against each other but only along a line or even only at points. In this case, the creation of a continuous in Figure 11 shown weld seam 18 for connecting the two arresters 2 is not possible or leads to a faulty weld seam 18.

[0035] To compensate for such bending errors or component tolerances, the conductors 2 to be connected are pressed together by applying a contact force F using a pressing tool 20. This is shown in Figure 1a ) on the right. The arresters 2 thus lie flat against one another and can be reliably welded. Typically, a casing 17 of at least one of the pouch cells 19 is used as a support. The casing 17 can, for example, be a cell frame of one of the pouch cells 19 or a battery module housing or the like. The disadvantage, however, is that bending errors cannot be fully compensated for and thus a zero gap between the arresters 2 to be connected cannot be achieved. In addition, a corresponding pressing tool 20 is complex to adjust.

[0036] A further problem is the connection of several pouch cells 19 to form a parallel circuit. For this purpose, a cell connector 21 known from the prior art is typically used. If the pouch cells 19 to be connected in parallel or their casings 17 or even a cell frame of the pouch cells 19 have a height offset from one another, this can lead to the cell connector 21 resting obliquely on the arresters 2 to be connected. This also creates a gap, as a result of which the cell connector 21 cannot be welded flatly to the arresters 2 to be connected. To compensate for this height difference, cell connectors 21 with curved sections are known. This is described in Figure 1b) is shown on the right. However, this places comparatively high demands on the most precise positioning of the components to be joined in a welding process. If more than two pouch cells 19 are to be connected in parallel, this problem can become even more acute.

[0037] With the help of a Figure 2With the cell connector 1 shown, pouch cells 19 to be connected or contacted can be contacted particularly reliably by means of a welding process. The cell connector 1 according to the invention comprises at least one essentially strip-shaped element 4. This comprises five sections 4.1, 4.2, 4.3, 4.4, 4.5, which are arranged one behind the other in a longitudinal direction L on the essentially strip-shaped element 4. The essentially strip-shaped element 4 has a small extension in a thickness direction D that is orthogonal to the longitudinal direction L and the width direction B, compared to an extension in the longitudinal direction L and a width direction B that is orthogonal to the longitudinal direction L. The first section 4.1 and the fifth section 4.5 each form one half of a closure element 5.1 and 5.2. The second section 4.2 forms a first clamping surface 6.1 and the fourth section 4.4 forms a second clamping surface 6.2.The third section 4.3 forms a deflection element 7. A folding axis 8 extends through the deflection element 7 in the width direction B. The essentially strip-shaped element 4 can be folded or closed about the folding axis 8. In order to enable comparatively simple bending or folding of the essentially strip-shaped element 4 about the folding axis 8, the flexural rigidity of the deflection element 7 is reduced by inserting perforations 10 into the deflection element 7 or the third section 4.3. The perforations 10 can be as shown in FIG. Figure 2shown by rectangular cutouts. However, the perforations 10 can have any desired shape. In addition or alternatively to the perforations 10, the deflection element 7 can also comprise a hinge 11 or be formed by it. This is shown in a detailed view A. If the hinge 11 forms the third section 4.3, the cell connector 1 according to the invention is formed by at least two essentially strip-shaped elements 4. In this case, the respective essentially strip-shaped elements 4 can be made of the same or a different material. For example, one of the essentially strip-shaped elements 4 can be made of a conductive material M, which in Figure 11shown, and the other substantially strip-shaped element 4 is made of a current-insulating material I. In general, however, the complete cell connector 1 can be made exclusively of the conductive material M or the insulating material I. The cell connector 1 can also be made of a conductive material, wherein one of the substantially strip-shaped elements 4 is made of a first conductive material M, for example aluminum, and a second substantially strip-shaped element 4 is made of a further conductive material M, for example copper. Figure 2shows a further detailed view A, in which, instead of a hinge 11, an elastic material 12 is shown for forming the third section 4.3. This can be an elastomer, for example. Any elastic material is conceivable for forming the third section 4.3, for example rubber, caoutchouc, silicone or the like. In particular, the third section 4.3 or the deflection element 7 can also be profiled at least in sections. This allows a bending resistance about the folding axis 8 and about the longitudinal direction L to be specifically adjusted. The third section 4.3 can also have a conductive material M, in particular in the form of a film hinge.

[0038] The first section 4.1 and the fifth section 4.5, or the respective half closure elements 5.1 and 5.2, have a matching geometric shape. In the example in Figure 2The first section 4.1 forms a tab, and the fifth section 4.5 forms a pocket for receiving the tab. If the essentially strip-shaped element 4 is bent around the folding axis 8, the respective halves of the closure element 5.1 and 5.2 are aligned with each other so that they can form a positive connection. To secure the positive connection, the respective closure element halves 5.2 and 5.2 can also be joined by an additional frictional connection and / or material connection.

[0039] Figure 3shows a plan view of a cell connector 1 according to the invention according to an alternative embodiment. A substantially rectangular recess is formed in the second section 4.2 or the first clamping surface 6.1 to form a welding window 13. However, the welding window 13 can also have any shape other than rectangular. The welding window 13 provides improved accessibility of a welding tool to the conductors 2 and / or strands 3 enclosed by the cell connector 1, which is Figures 10 and 11 is illustrated.

[0040] Figure 4 shows a plan view of a cell connector 1 according to the invention with a plurality of essentially strip-shaped elements 4. The plurality of essentially strip-shaped elements 4 are each connected to one another via a web 14. In the example in Figure 4the web 14 is connected to a second section 4.2 of a substantially strip-shaped element 4. In this case, one or more of the substantially strip-shaped elements 4 can also have a welding window 13. It is not absolutely necessary that all deflection elements 7 of the substantially strip-shaped elements 4 are designed identically. For example, any number of the substantially strip-shaped elements 4 can have perforations 10, a hinge 11 and / or an elastic material 12 to form the deflection element 7. In general, however, it is also conceivable that at least one web 14 is also connected, at least in sections, to the fourth section 4.4 of one of the substantially strip-shaped elements 4. With the aid of the Figure 4 Using the cell connector 1 shown, several galvanic cells or pouch cells 19 can be connected in parallel to one another in a particularly simple manner.

[0041] In the closed or folded state, the essentially strip-shaped element 4 encloses two conductors 2 and / or strands 3 to be connected. The essentially strip-shaped element 4 exerts a contact force F on the components to be connected. To increase this contact force F, as in Figure 5 shown, at least a region of one of the sections of the substantially strip-shaped element 4 may be curved. In the example in Figure 5 the entire second section 4.2 is curved around the width direction B. The resulting spring effect can then increase the contact force F. It is also conceivable that several sections 4.1 to 4.5 of the essentially strip-shaped element 4 are curved or have only partially curved areas.

[0042] An increase in the contact force F is also possible by contouring the first and / or second half of the closure element 5.1 and 5.2. Figure 6 a detailed view of a Figure 5 shown section BB. The contour 22 can have any shape. For example, the contour 22 can be formed by conical or pyramidal stumps projecting in the thickness direction D. The half closure element 5.1 or the half closure element 5.2 can also have a wave-shaped cross-section in the width direction B.

[0043] Figure 7 shows a plan view of a cell connector 1 according to the invention with several essentially strip-shaped elements 4 according to an alternative embodiment. In the example in Figure 7Perforations 15 are introduced into a web 14 connecting two essentially strip-shaped elements 4. The perforations 15 reduce the flexural rigidity of the web 14 along the longitudinal direction L. This makes it easier to compensate for a height offset in the thickness direction D when two pouch cells 19 are connected in parallel. Here, too, the perforations 15 can have any cross-sectional shape. Preferably, the perforations 15 are rectangular.

[0044] Figure 8 shows a detailed view of a Figure 7 The cross-sectional view CC shown in FIG. By reducing the material thickness in a material-containing section of the web 14, the flexural rigidity of the web 14 can be specifically adjusted to a desired value. The web 14 can also have a specific cross-sectional shape in the width direction B, for example, a corrugated cross-sectional shape.

[0045] Figure 9shows a plan view of a cell connector 1 according to the invention according to a further alternative embodiment. In the example in Figure 9 a substantially strip-shaped element 4 has a connecting flange 16, which extends from the second section 4.2 and / or from the fourth section 4.4 in the width direction B. By means of the connecting flange 16, a simple and reliable contacting of the substantially strip-shaped element 4 to a higher-level current-carrying component, for example a current contact rail or a conductor of a battery module, is possible. The connecting flange 16 can be connected to the higher-level current-carrying component in any desired manner, in a form-fitting, force-fitting and / or material-fitting manner. In the example in Figure 9Two through holes are provided in the connecting flange 16 to connect the essentially strip-shaped element 4 to the higher-level current-carrying component by means of a screw connection. If a metal screw is used, current can also flow through the screw. However, the connecting flange 16 can also be welded, soldered, or riveted to the higher-level current-carrying component, for example. Appropriate structural modifications can also be made to the connecting flange 16, for example, to insert it into the higher-level current-carrying component.

[0046] Figure 10shows a schematic diagram of a method 100 according to the invention for contacting at least two galvanic cells, for example two pouch cells 19. In method step 101, the arresters 2 and / or stranded wires 3 (not shown here) to be connected are aligned with one another in such a way that they lie on one another as flatly as possible in order to produce a weld seam 18 with a particularly high level of reliability. In method step 102, a cell connector 1 according to the invention consisting of a substantially strip-shaped element 4, which can optionally be pre-bent, is pushed between the arresters 2 to be connected and a casing 17 of one of the pouch cells 19 or a frame of a battery module. In method step 103, the at least one substantially strip-shaped element 4 is folded over about the folding axis 8, whereby the first and second clamping surfaces 6.1 and 6.2 are positioned on the arresters 2 and / or stranded wires 3 to be connected.Strands 3 lie flat and are pressed together with the aid of a contact force F. The at least one essentially strip-shaped element 4 forms a receptacle 9 for receiving the components to be connected. In the folded state, the first half of the closure element 5.1 and the second half of the closure element 5.2 are connected in order to prevent unintentional opening of the essentially at least one strip-shaped element 4 in the folded state. The pouch cells 19 to be contacted are then transported to a welding device. Thanks to the closed cell connector 1, the fixed components to be contacted, i.e. the arresters 2 and / or strands 3, cannot shift relative to one another. In method step 104, the arresters 2 and / or strands 3 are welded. Laser welding is preferably used for this purpose.

[0047] Figure 11shows various sectional views through a Figure 10 shown section DD. Depending on the design of the cell connector 1 used, four different weld seams 18 are created. Figure 11a ) and b) weld seams 18 through a cell connector 1 which has no welding window 13, and the Figures 11c ) and d) weld seams 18 when using a cell connector 1 with a welding window 13. Furthermore, Figure 11a ) and c) an application of a conductive material M to form the fourth section 4.4 or the second clamping surface 6.2. Thus, the weld seam 18 can extend into the second clamping surface 6.2. According to the Figures 11b) and d), this is not possible, since the fourth section 4.4 or the second clamping surface 6.2 is formed from a current-insulating material I. This allows the cell connector 1 to act as a bath support. However, if the weld seam 18 extends into the fourth section 4.4, a particularly reliable contacting of the conductors 2 and / or strands 3 to be connected can be ensured. In the example of Figure 11a ) and b), a targeted alloying of the weld seams 18 can also be achieved by melting the second section 4.2. In general, it is also possible that in the design in Figure 11d ) the complete cell connector 1 consists of the current-insulating material I. The welding window 13 nevertheless ensures that the arrester 2 and / or strands 3 to be connected can be welded.

[0048] Figure 12shows a side view of a laser welding process for contacting two electrical cables by means of the cell connector 1 according to the invention. Figure 12 serves to illustrate that instead of at least one arrester 2, one or more strands 3 of one or more current-carrying cables can also be fixed with the aid of a cell connector 1 according to one of the embodiments described above in order to be able to weld them particularly reliably.

Claims

1. Cell connector (1) for interconnecting at least two conductors (2) and / or stranded wires (3), the cell connector being composed of at least one substantially strip-shaped element (4), comprising at least five portions (4.1, 4.2, 4.3, 4.4, 4.5) arranged one behind the other on the strip-shaped element (4) in a longitudinal direction (L), characterized in that a first portion (4.1) forms a first half (5.1) of a closure element, a second portion (4.2) forms a first clamping surface (6.1), a third portion (4.3) forms a deflection element (7), a fourth portion (4.4) forms a second clamping surface (6.2) and a fifth portion (4.5) forms a second half (5.2) of the closure element, and the third portion (4.3) being designed to allow the first portion (4.1) and the second portion (4.2) to be folded over relative to the fourth portion (4.4) and fifth portion (4.5) about a folding axis (8) in a width direction (B) running orthogonally to the longitudinal direction (L) and running through the third portion (4.3), so that, in a folded up state of the strip-shaped element (4), at least a portion of the first and the second clamping surface (6.1, 6.2) lie opposite one another substantially in a thickness direction (D) running orthogonally to the longitudinal direction (L) and the width direction (B) and thus form a receptacle (9) for the conductors (2) and / or stranded wires (3) and, in the folded up state of the strip-shaped element (4), the first portion (4.1) and the fifth portion (4.5) can be interconnected in order to fix the at least one strip-shaped element (4) in the folded up state.

2. Cell connector (1) according to claim 1, characterized in that the third portion (4.3) comprises at least one perforation (10), a hinge (11) and / or an elastic material (12) and / or is profiled at least in portions.

3. Cell connector (1) according to either claim 1 or claim 2, characterized in that the first portion (4.1) and the fifth portion (4.5) are designed to form a form-fitting connection, in particular by bending, flanging, rolling or clinching at least one of the portions (4.1, 4.5); and / or the first portion (4.1) and the fifth portion (4.5) are designed to form a force-locking and / or integral bond, in particular by riveting, screwing, welding and / or gluing the portions (4.1,4.5).

4. Cell connector (1) according to any of claims 1 to 3, characterized in that the second portion (4.2) has a recess for forming a welding window (13), in particular a substantially rectangular recess, which recess runs completely in the thickness direction (D) through the second portion (4.2), a longer edge of the recess running in the longitudinal direction (L).

5. Cell connector (1) according to any of claims 1 to 4, characterized in that at least two strip-shaped elements (4) arranged parallel to one another in the longitudinal direction (L) are connected via at least one connecting element (14) extending from the second portion (4.2) and / or from the fourth portion (4.4) in the width direction (B) away from the strip-shaped element (4) and running in the longitudinal direction (L).

6. Cell connector (1) according to claim 5, characterized in that the connecting element (14) has at least one perforation (15), in particular the connecting element (14) having a smaller thickness in the thickness direction (D) than the strip-shaped element (4) and / or the connecting element (14) being corrugated in the width direction (B).

7. Cell connector (1) according to any of claims 1 to 6, characterized in that at least one strip-shaped element (4) has a connecting flange (16) for contacting the strip-shaped element (4) with a current-carrying component arranged above the strip-shaped element (4), which flange runs in the longitudinal direction (L) and extends in the width direction (B) away from the second portion (4.2) and / or fourth portion (4.4).

8. Cell connector (1) according to any of claims 1 to 7, characterized in that in order to increase a contact pressure (F), acting in the thickness direction (D), of the first clamping surface (6.1) and second clamping surface (6.2) on the conductors (2) and / or stranded wires (3) arranged in the receptacle (9) in the folded up state of the at least one strip-shaped element (4), the second portion (4.2) is curved at least in portions in the thickness direction (D) and / or at least one half of the closure element (5.1, 5.2) has a contour (22) extending in the thickness direction (D) in the connected state of the closure element.

9. Cell connector (1) according to any of claims 1 to 8, characterized in that the at least one strip-shaped element (4) is formed entirely from a conductive material (M), in particular a metal or a metal alloy and preferably from a metal sheet, or the at least one strip-shaped element (4) is formed at least in portions from a conductive material (M), in particular a metal or a metal alloy and preferably from a metal sheet and at least in portions from a current-insulating material (I), the insulating material (I) advantageously forming at least the fourth portion (4.4).

10. Method (100) for contacting at least two galvanic cells by means of at least one cell connector (1) according to any of claims 1 to 9, characterized by at least the following method steps: - aligning the conductors (2) and / or stranded wires (3) to be interconnected; - arranging the cell connector (1) relative to the conductors (2) and / or stranded wires (3) such that the fourth portion (4.4) is supported at least in portions with a side (S1) facing away from the receptacle (9) on a casing (17) of at least one galvanic cell and / or at least one conductor (2) and / or at least one stranded wire (3) rests on a side (S2) of the fourth portion (4.4) facing towards the receptacle (9); - folding the first portion (4.1) and second portion (4.2) across the folding axis (8) running through the third portion (4.3) in the width direction (B) in order to bring the strip-shaped element (4) into the folded up state; - closing the closure element; - welding the conductors (2) and / or stranded wires (3) to be connected or welding at least one portion of the cell connector (1) to the conductors (2) and / or stranded wires (3) to be connected, in particular by means of at least one weld seam (18) running in the longitudinal direction (L), laser welding being preferably used as the welding method.