Battery cell assembly for a high-voltage battery system

Abstract

Battery cell assembly, comprising battery cells (1) stacked one behind the other in a stacking direction (x), the battery cells having cathode arresters (3) and anode arresters (5) aligned in the stacking transverse direction (y), wherein the cathode arresters (3) and the anode arresters (5) of the battery cells (1) are electrically interconnected by means of a busbar system (6) according to a predetermined wiring scheme (Vsoll), wherein an activation device (37) is assigned to the battery cell assembly, with which switching units (pin) in the busbar system (6) can be activated depending on a wiring scheme (Vsoll) to be set, in order to define the wiring scheme (Vsoll) in the battery cell assembly, and wherein in the battery cell assembly all cathode arresters (3) are arranged on a cathode side of the battery cell assembly and all anode arresters (5) are arranged on an anode side of the battery cell assembly, which are oriented perpendicular to the stacking direction (x) of the cathode side. opposite, characterized bythat the busbar system (6) has transverse current rails (19) extending between the cathode side and the anode side of the battery cell assembly, and that, viewed in the stacking direction (x), a transverse current rail (19) is arranged between adjacent battery cells (1), that the transverse current rail (19) can be coupled or decoupled with one or both cathode arresters (3) of the two adjacent battery cells (1) by means of switching units (pin), and that the transverse current rail (19) can be coupled or decoupled with one or both anode arresters (5) of the two adjacent battery cells (1) by means of switching units (pin).

Description

[0001] The invention relates to a battery cell assembly for a high-voltage battery system according to the preamble of claim 1 and to a method for producing such a battery cell assembly according to claim 10.

[0002] In common practice, a busbar is understood to be a component that is welded to the terminals of a battery cell. Busbars are used to electrically connect the battery cells in a battery cell array according to a specific wiring scheme, either in parallel and / or series. The busbar is usually a hybrid component consisting of plastic and at least one metal part. Depending on the desired parallel or series connection, the metal part (primarily a nickel-tin alloy) of the busbar is mounted onto a plastic body. After welding the metal part to the respective terminal of the battery cells, a battery cell array, such as a battery module, is formed in which the cells are connected in the desired parallel and series configuration.

[0003] A battery cell assembly of this type consists of battery cells stacked one behind the other in a single stacking direction. These cells have cathode and anode arresters perpendicular to the stacking direction. The cathode and anode arresters of the battery cells are electrically interconnected by means of a busbar system according to a predetermined wiring scheme.

[0004] In current technology, the battery cell stack is not flexible enough to easily adapt to new parallel and series configurations. For example, if twelve pouch or prismatic cells are present and the module needs to be changed from one wiring scheme (e.g., 3P4S) to another (e.g., 2P6S), the extensive modifications described below must be made. This is time-consuming, expensive, and prone to errors.

[0005] Thus, the cells are grouped differently depending on the wiring configuration (for example, 3P and 2P). In a 3P configuration, for instance, one side of the battery cell stack has three aluminum surge arresters (positive), then three copper surge arresters (negative), then three aluminum surge arresters, and then three copper collectors. In a 2P configuration, the sequence might be: two aluminum surge arresters - two copper surge arresters, two aluminum surge arresters - two copper surge arresters - two aluminum surge arresters. If the cells are not correctly stacked, the module must be scrapped. Converting from 3P to 2P requires extensive software modifications, changes to the visual inspection procedure, and ultimately, hardware adjustments. Therefore, a battery cell stack typically consists of a fixed parallel and series combination that cannot be changed.This means that every time a new parallel and series combination is needed, a separate module line is required. This significantly increases the cost of the module development line.

[0006] Furthermore, the following situation arises in the current state: The busbar is connected to the surge arrester in such a way that the cells are arranged in parallel and in series. The busbars are provided with corresponding slots in the metal busbar plate. This means that a separate busbar is required for each new parallel and series connection. This necessitates a large inventory, and the probability of selecting the wrong busbars is high. It is also crucial that the busbars are used correctly, otherwise the module must be scrapped. This means not only that a large inventory of different busbars is needed for each parallel and series combination, but also that it is necessary to check whether the busbars are correctly positioned and the correct busbar pair has been selected.

[0007] The metallic part of a busbar known from the prior art is made of a nickel-tin alloy. This offers good corrosion resistance compared to copper. However, for an aluminum surge arrester, it would be better to use an aluminum alloy material, as aluminum can be welded to aluminum sheet. Since the metal part must connect both the copper and aluminum surge arresters, it is not possible to use different metal plates. The current metal plate of the busbar is not optimal in terms of weldability and corrosion resistance.

[0008] Different busbar systems for a battery cell assembly are known from WO 2019 / 060047 A1 and WO 2016 / 053415 A1.

[0009] The object of the invention is to provide a battery cell assembly for a high-voltage battery system which allows a greater degree of freedom with regard to the electrical interconnection of the battery cells compared to the prior art.

[0010] The problem is solved by the features of claim 1 and claim 10. Preferred embodiments of the invention are disclosed in the dependent claims.

[0011] The battery cell assembly according to the invention consists of a number of battery cells stacked one behind the other in a stacking direction. These cells have cathode and anode connectors perpendicular to the stacking direction. The cathode and anode connectors of the battery cells are electrically interconnected according to a predefined wiring scheme and connected to a positive cell assembly terminal and a negative cell assembly terminal. In the battery cell assembly, all cathode connectors can be grouped on a cathode side of the battery cell assembly, while all anode connectors can be grouped on an anode side of the battery cell assembly that is opposite the cathode side perpendicular to the stacking direction.In this way, a stacking error during the assembly of the battery cell assembly can be avoided, in which, due to an incorrectly stacked battery cell, the orientation of the cathode and anode current collectors cannot be aligned with the circuit diagram in the battery cell assembly. According to the invention, however, the battery cells are always stacked in the same orientation, regardless of the intended circuit diagram in the battery cell assembly, so that stacking errors due to incorrectly stacked battery cells can be avoided.

[0012] According to the characterizing part of claim 1, an external activation device is assigned to the battery cell assembly for defining the wiring scheme. Depending on the desired wiring scheme to be set, switching units in the busbar system can be activated by the activation device to define the wiring scheme in the battery cell assembly. For example, during a battery cell assembly manufacturing process, the switching units located in the battery cell assembly can remain in their locked position, i.e., deactivated, so that no wiring scheme has yet been defined. Only at the end of the manufacturing process can an activation step take place, in which a desired wiring scheme can be set using the activation device. According to the invention, a busbar system can therefore be provided independently of the wiring scheme, with which the manufacturing process of the battery cell assembly can be made more flexible.After the activation step has been completed, the activation device can be removed from the busbar system of the battery cell assembly.

[0013] According to the invention, regardless of the intended parallel or series connection, all cells can be arranged such that all anode current collectors are stacked vertically. Likewise, all cathode current collectors are stacked vertically. However, there are no alternating aluminum and copper current collectors stacked vertically. This prevents errors when assembling the cells. This also simplifies the assembly of the cells in the module. A compression pad can be placed after every three cells. It is also possible to place a compression pad after each cell. This means that the anode side of the cell stack has only negative current collectors (copper) and the cathode side of the cell stack has only positive current collectors (aluminum).

[0014] Furthermore, according to the invention, the anode-side busbar and the cathode-side busbar can be identical and have grooves or slots into which the current collectors are welded. Only the slots are made of metal and are embedded in a plastic cover. It is important that each slot is electrically isolated from the others. Therefore, the cathode and anode busbars according to the invention do not have a metal plate as in conventional busbars, but only metallic inserts with slots, while the rest of the busbar system is a plastic body. The individual slots are electrically isolated from the other slots.

[0015] According to another aspect of the invention, the busbar system consists of a plastic part with metallic inserts in which slots are provided. The current collector is welded into these slots. A metallic connector, also integrated into the plastic matrix, is located between the slots. Switching units are integrated between the slots and a transverse busbar (also referred to as a copper strip) described later. These switching units can be switched on and off based on signals from a microprocessor of the activation device. The switching units connect the individual slots to each other and to the copper strips between them. In this way, various parallel combinations are possible. The anode busbar, which is connected to the copper current collector (with tab), has metallic inserts made of a nickel-tin alloy.The cathode busbar, onto which the aluminum current collector is welded, has metallic inserts made of an aluminum alloy.

[0016] In the cathode busbar, the respective metallic insert can be made of an aluminum alloy. Since both the positive aluminum current collector and the metallic insert are made of the same material, there will be no stress corrosion cracking. The switching units in the anode and cathode busbars are activated by an activation device. In this case, the activated switching unit can electrically connect the metallic insert to a cross-current bar (hereinafter also referred to as a copper strip), allowing current to flow from the current collector to the copper strip. The switching elements of the switching units can be made of a nickel-tin alloy or brass. Now all parallel combinations are possible. The wiring of the battery cell stack can be easily changed by means of a corresponding microprocessor signal from the activation device.

[0017] A key aspect of the invention is that the busbar system comprises not only a cathode busbar and an anode busbar, but also a central busbar that connects the cathode and anode busbars. The central busbar is also made of a plastic body. It has horizontal and vertical copper strips (i.e., cross-current rails) embedded in the plastic. Switching units are located between the horizontal and vertical copper strips. These switching units can be switched on or off based on a microprocessor activation signal. The switching units connecting the copper strips (i.e., cross-current rails) create various series combinations within the battery cell assembly (i.e., within the battery module). The central busbar, the cathode busbar, and the anode busbar are preferably not three separate components.Rather, the three busbars are preferably combined into a common, U-shaped component made of plastic material, in which copper strips, switching units and metal inserts (with slots) are embedded.

[0018] According to the invention, the positive and negative terminals can be located in the cathode busbar and the anode busbar, respectively. Alternatively, it is also possible to arrange both terminals in the cathode busbar. In this case, an additional copper strip is required so that the negative terminal can be routed to the cathode busbar.

[0019] The switching units integrated into the busbar system can be activated by an external activation device that generates a local magnetic field. This magnetic field activates several switching units, which are intended to implement the desired parallel and / or series connection. The activation device can be controlled by a microprocessor. The device is placed over the busbar system from above. Based on the desired parallel and / or series connection, a magnetic field is generated around a specific switch. This magnetic field releases a locking spring. The switching units are placed onto the spring, which then moves upwards. The switching units close the circuit and connect the cells in the desired parallel or series connection. This activation of the switching units only occurs after the busbar has been welded to the current collector.Normally, the current collector (with the tab) is connected to the metal slots in the plastic part by laser welding. Once the busbar is welded and the switching unit is activated, the module has the appropriate parallel and series combination.

[0020] The switching unit activation device is powered externally. It generates a local magnetic field, which releases the latch holding the switching unit in place. A spring then pushes the switching unit down. Once pressed down, the switching unit contacts the copper strip, creating a series and parallel circuit. The microprocessor only powers the switching units that need to be activated. Other switching units do not receive a magnetic field and therefore remain locked and deactivated.

[0021] The main differences between the invention and the prior art are as follows: The cells in the battery cell stack are arranged such that all copper current collectors (negative terminals) are located on one side and all aluminum current collectors (positive terminals) on the other side. The anode busbar has slots in metallic inserts made of a nickel-tin alloy. Copper current collectors with tabs are laser-welded into these slots. Each slot is insulated from the others. There is no metal plate as in current busbars. The cathode busbar has slots similar to the anode busbar. Here, the slots are housed in an aluminum composite insert. An aluminum current collector with a tab is laser-welded to the slots. Each slot is insulated from the others. There are cross-connectors (i.e., copper strips) that are placed between the slots and embedded in the plastic body.The copper strips are located in the anode and cathode busbars. These copper strips have gaps. Switching units are positioned in these gaps. When the switching units are activated, current flows through the copper strip. Otherwise, the copper strip forms an open circuit. Copper strips with switching units in the cathode and anode busbars form a parallel combination.

[0022] The switching units are made of a nickel-tin alloy or brass. A center busbar is located between the cathode and anode busbars. Here, copper strips are embedded in the plastic body. Switching units are also embedded in the plastic body. When the switching units are activated, the copper strips close a circuit. The copper strips and switching units in the center busbar form a series circuit. The cathode and anode busbars, along with the center busbar, together form a single component. This component is manufactured by inserting a metal insert (with slots), copper strips, and switching units into a holder, and then injection-molding plastic over these metal parts. The metal insert, the switching unit (in its locked position), and the copper strips are electrically connected and together form a circuit.The plastic used consists of acrylic, silicone, or high-temperature-resistant polymers that can absorb the heat from welding. The switching units are switched on and off by a magnetic field. This local magnetic field is generated by a controlled current in the switching unit activation module. This current is controlled by a microprocessor. The switching units are activated after the busbar has been welded to the current collector.

[0023] Once activated, the switching units remain permanently in that position for the entire lifespan of the module. The switching unit activation device is part of a module assembly machine and is removed from the busbar system once the switching units are activated. The microprocessor has different programs, so each subsequent module can have a different parallel and series connection. Every second module (or battery cell assembly in general) can have a different parallel and series connection. The busbar system remains the same regardless of the parallel and series connection. Only the activation of the switching units results in a parallel and series connection for a specific module. This allows for flexibility in the mass production of modules. Welding the current collector (with tab) to the metallic insert in the anode and cathode busbar is typically done by laser welding.Other methods such as soldering, brazing, ultrasonic welding, and die casting are also possible. The positive terminal is connected to the cathode busbar, and the negative terminal to the anode busbar. It is also possible to connect both the positive and negative terminals to a common busbar. For this purpose, an additional copper strip runs from the anode busbar to the cathode busbar. This copper strip conducts the current from the negative terminal to the anode busbar.

[0024] The busbar system according to the invention is a universal busbar system with which any parallel and series combinations can be generated. It is no longer flexible once the switching units are activated by the activation device. In this case, the busbar system is fixed to a specific wiring scheme. The invention is particularly applicable to pouch cells or prismatic cells.

[0025] The following are key aspects of the invention highlighted in detail: The cathode and anode arresters of the battery cells can be electrically interconnected by means of a busbar system according to the invention. The busbar system includes switching units that allow different current paths between the battery cells to be enabled or disabled. In this way, the battery cells can be connected to each other in different configurations, in parallel and / or series.

[0026] In one technical implementation, the busbar system can have transverse busbars. These extend between the cathode and anode sides of the battery cell array. A transverse busbar is arranged between adjacent battery cells. Each transverse busbar can be connected or disconnected at a cathode switching point to one or both cathode arresters of the adjacent battery cells by means of switching units. Alternatively and / or additionally, the respective transverse busbar can be connected or disconnected at an anode switching point to one or both anode arresters of the adjacent battery cells by means of switching units. Furthermore, the transverse busbar can be subdivided into busbar segments perpendicular to the stacking direction. These segments can be electrically connected or disconnected by means of at least one switching unit.A battery cell located at one end of the battery cell assembly can have its cathode connector connected to the positive terminal of the assembly. Conversely, a battery cell located at the other end of the battery cell assembly can have its anode connector connected to the negative terminal of the assembly.

[0027] For ease of handling, such as during installation of the busbar system, it is preferred that the transverse busbars and the switching units are embedded in a one-piece, U-shaped plastic component. This U-shaped plastic component can encompass the battery cell assembly from above. Furthermore, the U-shaped plastic component can be formed from a cathode busbar arranged on the cathode side of the battery cell assembly, an anode busbar arranged on the anode side of the battery cell assembly, and a central busbar connecting the cathode and anode busbars. The central busbar preferably extends across the top surface of the battery cell assembly.

[0028] Electrically isolated metal inserts can be embedded in the cathode busbar. Each metal insert can have a slot into which a cathode arrester of the battery cells can be inserted and thus electrically connected. Similarly, electrically isolated metal inserts can be embedded in the anode busbar. Each of these inserts can have a slot into which an anode arrester of the battery cells can be inserted and thus electrically connected.

[0029] In the busbar system according to the invention, the metal inserts in contact with the anode arresters are made of a copper-nickel-tin alloy. The metal inserts in contact with the cathode arresters are made of an aluminum alloy. In contrast, the busbar metal insert known from the prior art is made of a copper-nickel-tin alloy. The switching elements are also made of copper-nickel-tin or brass.

[0030] In the stacking direction, a transverse busbar can be positioned between adjacent insert sections of the cathode busbar and the anode busbar. In this case, the insert sections can form electrical contacts that can be electrically coupled to the arranged transverse busbar via the switching units.

[0031] The switching units can each have a stroke-adjustable switching element within a switching housing. After completion of the battery cell assembly, the switching units can be in a decoupling position, in which electrical decoupling is established in the busbar system. In the decoupling position, the switching element of the respective switching unit can be supported against a latch in the locking position by means of spring preload. When the latch is moved from its locking position to its release position, the stroke-adjustable switching element can be moved into its coupling position by means of the spring preload. In the coupling position, the switching element can establish an electrical connection in the busbar system.

[0032] The busbar system can have a multitude of switching units which, depending on a desired wiring scheme, must either remain in the decoupling position or be moved into the coupling position. Against this background, a process-oriented, simple control of the busbar system's switching units is of great importance. In a preferred embodiment, the latch of each switching unit can be moved from its locking position to its release position by means of magnetic force. Using the preferably external activation device, local magnetic fields can be generated on the busbar system depending on a set target wiring scheme. This allows the latches of the selected switching units to be moved into the release position by magnetic force, thus bringing their switching elements into the coupling position.

[0033] An embodiment of the invention is described below with reference to the accompanying figures.

[0034] They show: Fig. 1 to Fig. 3 views each of a battery cell assembly with associated busbar system; Fig. 4 the busbar system with omitted battery cell assembly; Fig. 5 to Fig. 8 views each, illustrating the structure and function of switching units; Fig. 9 a switching matrix for setting different wiring schemes in the battery cell assembly; Fig. 10a in a view according to the Fig. 3 the current path in a first circuit diagram; Fig. 10b a simplified circuit diagram resulting from the first wiring scheme; Fig. 11a and Fig. 11b each views according to the Fig. 10a and Fig. 10b, which concern a second wiring scheme; and Fig. 12 to Fig. 22 views of further examples.

[0035] In the Fig. 1 to Fig. Figure 3 shows a battery cell assembly consisting of battery cells 1 stacked one behind the other in the stacking direction x. The battery cells 1 can, for example, be pouch cells which have cathode arresters 3 and anode arresters 5 on both sides in the stacking transverse direction y. According to the invention, in the Fig. 1 to Fig. 3 all cathode arresters 3 on the (in the Fig. 1 to Fig. 3 right) cathode side of the battery cell assembly grouped, while all anode current collectors 5 are on the (in the Fig. 1 to Fig. 3 left) anode side of the battery cell assembly are grouped, which is opposite the cathode side in the stack transverse direction y.

[0036] In the Fig. Figure 3 shows an exploded view of the battery cell assembly, in which a cathode busbar 7, located on the right cathode side, and an anode busbar 9, located on the left anode side, are shown detached from the battery cell stack and rotated by 90° so that their inner surfaces, which face the battery cell stack in the assembled state, are visible. The cathode busbar 7 and the anode busbar 9 are shown in the Fig. 2 are connected to each other via a central busbar 11, which extends over the top of the battery cell assembly. The cathode busbar 7, the anode busbar 9 and the central busbar 11 are components of a busbar system 6 according to the invention ( Fig. 2), which has the switching unit pin described later, with the help of which different current paths I ( Fig. 10a or Fig. 11a) between the battery cells 1 can be enabled or disabled, so that the battery cells 1 can be connected to each other in parallel and / or series in any connection scheme. In the Fig. 2 the busbar system 6 according to the invention is realized as a U-shaped plastic component that surrounds the battery cell assembly from above.

[0037] As from the Fig. As can be seen from Figure 4a, the cathode busbar 7 has electrically isolated metal insert parts 13 with receiving slots 15 (in the Fig. 3 shown). A corresponding cathode arrester 3 of the battery cells 1 can be inserted into each of the receiving slots 15 of the insert parts 13 and thus welded in place, i.e., electrically connected. In the same way, electrically isolated insert parts 17 are also located in the anode busbar 9 ( Fig. 4) with 15 recording slots ( Fig. 3) embedded, into which the anode arresters 5 of the battery cells 1 can be inserted and welded to establish an electrical connection.

[0038] In the Fig. Figure 4a shows the busbar system 6 with the battery cell stack omitted. The cathode busbar 7, the middle busbar 11, and the anode busbar 9 are shown in the Fig. Figure 4a does not depict the components aligned in a U-shape, but rather shows them all in a common plane. Accordingly, the busbar system has 6 transverse busbars 19 extending in the stacking direction y between the cathode and anode sides of the battery cell assembly. One of the transverse busbars 19 is arranged between each adjacent battery cell 1. Viewed in the stacking direction x, the transverse busbars 19 are positioned between adjacent insert parts 13, 17 in the anode busbar 9 and the cathode busbar 7. The transverse busbars 19 extend in the stacking direction y beyond the central busbar 11 into the cathode busbar 7 and the anode busbar 9.

[0039] The insert parts 13, 17 form electrical contacts that can be electrically coupled to the respective cross-current rail 19 via the switching units Pin. The switching units Pin are located in the Fig. 4a are only roughly schematically indicated by circular areas. As can be seen from the Fig. As further shown in Figure 4a, the cathode busbar 7 has a positive cell assembly terminal 21, while the anode busbar 9 has a negative cell assembly terminal 23. The two terminals 21 and 23 are each electrically connected to a cathode arrester 3 and an anode arrester 5, respectively, of a front-end battery cell 1.

[0040] As from the Fig. As further shown in 4a, each of the transverse current rails 19 is divided in the stack transverse direction y into four individual rail segments, which can be electrically coupled or decoupled at a total of three central switching points using switching units Pin.

[0041] Alternatively to Fig. 4a is in the Fig. 4b shows a busbar system 6 that is largely identical to the one in the Fig. The busbar system 6 shown in 4a is different. Fig. 4a are in the Fig. 4b the positive and negative terminals 21, 23 are arranged in the cathode busbar 7. For this purpose, an additional cross-current rail 19 is installed in the busbar system 6, which connects the anode arrester 5 of the upper end-face battery cell 1 to the negative terminal 23.

[0042] The following will be based on the Fig. 5 to Fig. Section 8 describes the structure and function of the switching units Pin. Thus, the one in the Fig. The switching unit Pin shown in Figure 5 is also embedded in the busbar system 6, specifically in the plastic material of the U-shaped plastic component. The switching unit Pin has a switching housing 25 in which a stroke-adjustable switching element 27 is guided. According to the Fig. 4 to Fig. 6 The switching element 27 is pre-tensioned in the switching housing 25 by means of a spring 29. In addition, a latch 31 is mounted transversely to the switching element 27 in the switching housing 25 so as to be laterally adjustable. The latch 31 is in the Fig. 5 is pressed into its locking position by means of a compression spring 33. In the locking position ( Fig. 5) The switching element 27 is supported against the latch 31, thereby establishing electrical decoupling between the contact points K1 and K2 in the busbar system 6. According to the Fig. 4 to Fig. 7 a ferromagnetic component 35. By applying a local magnetic field to the switching unit pin, the latch 31 can therefore be moved against the compression spring force into a release position ( Fig. 6) can be adjusted. In this release position ( Fig. 6) The switching element 27 can be brought into its coupling position by means of the spring preload, in which the switching element 27 establishes an electrical coupling between the two contact points K1, K2 in the busbar system 6.

[0043] Immediately after completion of the battery cell assembly, all switching units Pin of the busbar system 6 are in their decoupling position ( Fig. 5) To assign a target wiring scheme V to the battery cell assembly soll ( Fig. 8) to imprint, an activation device 37 ( Fig. 8) are provided. With the help of the activation device 37, depending on the target wiring scheme V to be set, soll Local magnetic fields are generated on the busbar system 6. With their help, the latches 31 of selected switching elements Pin can be moved into the enable position, so that their switching elements Pin are in the coupling position ( Fig. 6 and Fig. 7) switch. After the local magnetic fields are lifted, the bolt 31 is returned to its locking position by means of the compression spring 33 ( Fig. 7) In this case, the bolt 31 engages positively in a corresponding recess 39 formed on the switching element 27. In this way, an unintentional return of the switching element 27 to its decoupling position ( Fig. 5) prevented.

[0044] Different wiring schemes are possible in the battery cell assembly, which are shown in the switching matrix of the Fig. The matrix lists nine switching elements, with all switching elements (Pin) shown in the top row. A "1" symbolizes a coupled state for each switching element (Pin), while a "0" symbolizes a decoupled state. On the right side of the switching matrix are two columns labeled "P" and "S," which correspond to the selected wiring scheme. "P" represents the number of parallel connections in the battery cell array, while "S" represents the number of series connections in the battery cell array.

[0045] For example, in the Fig. 10a and Fig. Figure 10b shows the current path I, which results from the first circuit diagram 1 P6S. Alternatively, in the Fig. 11a and Fig. Figure 11b shows the current path I resulting from a second circuit diagram 2P3S. The other circuit diagrams 3P2S, 2P2S, 4P1S and 6P1S can be formed in the same way.

[0046] The following is based on the Fig. 12 to Fig. 22 further embodiments of the invention are described. Accordingly, the switching units (Pin) are implemented as connecting elements, for example, as connecting pins. The Pins are arranged on the activation device 37 before the activation step is carried out. The release of the Pins is activated by an external power supply, which generates a local magnetic field. This magnetic field is generated by supplying current to the area near the switch to be actuated. The activation device 37 is, in turn, controlled by a microprocessor. Each Pin is surrounded by switches that control the current flow near the Pin. This device is arranged around the busbar system 6. Depending on which switch is actuated, a magnetic field is generated around specific Pins. This magnetic field releases the Pins and brings them into a current-conducting coupling position.The activated pins therefore close the circuit and connect the cells 1 in the desired parallel or series combination. This activation step only takes place after the busbar system 6 has been welded to the cathode and anode arresters 3, 5. Normally, the arrester 3, 5 is welded to the metal slots 15 in the busbar system 6 by laser welding. Once the busbar system 6 is welded to the cathode and anode arresters 3, 5 of the battery cells 1 and the activation step has subsequently been performed, the battery cell assembly has the corresponding parallel and series combination. Each subsequent busbar system 6 can have a different parallel and series combination. The activation device 37 is removed from the battery cell assembly after completion of the activation step. Following the activation step is a fastening step in which the connecting pins are permanently fixed in the busbar system 6.

[0047] In the activation step described above, the microprocessor of the activation device 37 sends current only to the areas near the pins that need to be activated. Other pins that do not receive a magnetic field are not pressed and remain out of service. It should be emphasized that activating the connecting pins by means of magnetic force is only one way to bring the pins into the coupling position. In this process, the activation device 37 releases the pin by locally triggering a magnetic field, so that the pin engages in a pin receptacle 40 ( Fig. 13) between metal inserts 41 and is pressed into the space between the two contacts K1 and K2. However, the invention is not limited to this variant. Rather, the connecting pins can also be brought into the coupling position in any other way.

[0048] In the illustrated embodiment, the connecting pin is made of solid material, such as copper or bronze.

[0049] As from the Fig. 13 and Fig. As can be seen from 14, the connecting pin in the pin receptacle 40 of the busbar system 6 is moved into its coupling position ( Fig. 14) retracted. In the coupled position, the connecting pin head rests laterally against the metal inserts 41, the upper half 43 of which is made of aluminum and the lower half 45 of which is made of bronze or copper. In the coupled position shown ( Fig. 14) The connecting pin connects the two contacts K1 and K2 in the busbar system 6.

[0050] This is followed by a laser welding step ( Fig. 15 and Fig. 16) Laser welding is used to permanently join the pin to the metal inserts 41. As mentioned earlier, the upper half 43 of the metal inserts 41 is made of aluminum and the lower half 45 of a copper alloy (for example, bronze). In the laser welding step, only the upper aluminum metal insert half 43 (melting temperature in the range of 660°C) is melted (see melt pool 46 in the Fig. 16), while the lower metal insert half 45, made of copper (melting point in the range of 1084°C), remains in the solid state. Thus, the process involves welding for aluminum and soldering for copper. Controlled heat input during the process reduces the seam width of the intermetallic joints, resulting in a more homogeneous interface with good mechanical, corrosion, and electrical properties. The laser soldering process is based on the principle of laser keyhole welding. The beam is generated by the laser welding device 50 ( Fig. 16 or Fig. 18) with an energy density of at least 1 MW / cm² 2The laser beam is focused onto the material surface, causing the aluminum material of the metal inserts 41 to melt and vaporize. The vaporized metal forms a hole in which the laser is reflected multiple times, increasing the metal's energy absorption. This high energy input enables a rapid process and selective melting of the upper aluminum layer, while the lower copper layer remains solid, hence the term brazing. The resulting molten layer thickness between the aluminum and copper can be reduced to less than 5 µm. The formation of an intermetallic bond between the aluminum and copper is minimized, resulting in a ductile metal joint with reduced electrical resistance. Argon helps to protect the weld from atmospheric contamination.

[0051] In the Fig. 17 and Fig. Figure 18 shows an alternative laser welding step. In this step, the metal inserts 41 are made entirely of one material, namely copper or a copper alloy such as bronze. The laser welding is performed without filler material. This means that the copper alloy pin and the metal insert 41 (copper alloy) melt at the interface, permanently bonding the pin to the metal insert. The shape of the pin is the same as in laser soldering, as already explained; however, no filler material is required.

[0052] In the Fig. 17 and Fig. 18. Laser welding takes place at the interface between the pin and the metal insert 41 (which is also made of a copper alloy). Here, the interface is melted under an argon atmosphere and then solidifies into a thin weld seam. In this way, the pin is permanently connected to the metal insert 41. The heat is applied locally at the interface between the metal insert 41 and the pin, so that the surrounding plastic body 47 of the busbar system 6 is not affected by this heat. Since copper is a strong heat reflector, it is advisable to use a green laser.

[0053] It should be emphasized that the invention is not limited to a welding connection of the connecting pins in the busbar system 6. Rather, the connecting pins can also be permanently attached to the busbar system 6 in any other way. By way of example, in the Fig. 19 to Fig. 22 the permanent fastening of the connecting pins in the busbar system 6 by means of a screw connection. According to the Fig. 19. The connecting pin is brought by means of the activation device 37 to the vicinity of the space between contacts K1 and K2 in the busbar system 6. The connecting pin is magnetically connected to that of the activation device 37. The activation device 37 releases the connecting pin by locally triggering a magnetic field. This pushes the connecting pin into the pin receiving space of the busbar system 6 and between contacts K1 and K2. In contrast to the previous embodiment, metal inserts 41 are not required.

[0054] The connecting pin has a screw hole 49, which is located in the Fig. 21 is penetrated by a screw 48. Alternatively, the connecting pin can be arranged according to the Fig. 22 are also screwed to the plastic body 47 of the busbar system 6 by means of several screws 48.

[0055] During the assembly process, the connecting pin is moved downwards until it comes into contact with the lower plastic body 47 of the busbar system 6. A screw 48 is then inserted through the center of the connecting pin and screwed into the plastic body 47. In this way, the connecting pin is permanently connected to the busbar system 6. The connecting pin connects the two contacts K1 and K2 of the busbar system 6.

[0056] In addition, an insulating panel can be 53 ( Fig. 22) made of flexible plastic (for example, polyurethane) is placed on the top of the connecting pin. The connecting pin is then screwed to the insulating plate 53 and the upper plastic body 47.

[0057] The insulating plate 53 prevents current from flowing to the outer body via the connecting pin. In this case, the connecting pin does not need to be connected to the lower plastic body 47. Normally, the connecting pin is connected to the insulating plate 53 before being inserted into the busbar system 6. The insulating plate 53 can be fastened with a central screw 48, with the activation device 37 then vacuum-locking the connecting pin to the insulating plate 53. It is also possible to use one insulating plate 53 for all connecting pins. Reference symbol list 1 battery cell 3 cathode drains 5 anode drains 6 Busbar system 7 Cathode Busbar 9 anode busbar 11 Middle Bus Bar 13 cathode-side insert parts 15 recording slots 17 anode-side insert parts 19 cross-rails 21 positive cell cluster terminal 23 negative cell cluster terminal 25 switch housings 27 Switching element 29 Switching element spring 31 bars 33 Locking spring 35 ferromagnetic component 37 Activation device 39 recess 40 pen holder 41 metal inserts 43 upper metal insert half 45 lower metal insert half 46 Melt bath 47 plastic bodies 48 screws 49 screw holes 50 laser welding device 53 Insulation board K1, K2 contact points Pin switching units x Stacking direction y Stacking transverse direction z Upward direction I Current path V soll Target wiring diagram QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2019 / 060047 A1

[0008] WO 2016 / 053415 A1

[0008]

Claims

[1] Battery cell assembly, with battery cells (1) stacked one behind the other in a stacking direction (x), which have cathode arresters (3) and anode arresters (5) aligned in the stacking transverse direction (y), wherein the cathode arresters (3) and the anode arresters (5) of the battery cells (1) are connected by means of a busbar system (6) according to a predetermined wiring scheme (V soll ) are electrically interconnected, characterized by , that an activation device (37) is assigned to the battery cell assembly, with which, depending on a circuit scheme to be set (V soll ) Switching units (pin) in the busbar system (6) can be activated to change the wiring scheme (V soll ) to be determined in the battery cell assembly. [2] Battery cell assembly according to claim 1, characterized by, that during the manufacturing process of the bastard cell assembly the switching units (pin) are in their decoupling position, i.e. deactivated, so that no wiring scheme is yet defined, and that at the end of the manufacturing process an activation step takes place in which predetermined switching units (pin) can be brought into their coupling position by means of the activation device (37), i.e. can be activated, so that the wiring scheme (V soll ) is specified in the battery cell assembly, and in particular, that after the activation step has been completed, the activation device (37) can be removed from the busbar system (6) of the battery cell assembly. [3] Battery cell assembly according to claim 1 or 2, characterized by, that different current paths (I) between the battery cells (1) can be enabled or disabled by means of the switching units (pin) located in the busbar system (6), so that the battery cells (1) can be connected to each other in different circuit schemes in parallel and / or series connection, and / or that in the battery cell assembly all cathode arresters (3) are arranged on a cathode side of the battery cell assembly and all anode arresters (5) are arranged on an anode side of the battery cell assembly, which is opposite the cathode side perpendicular to the stacking direction (x). [4] Battery cell assembly according to claim 3, characterized by, that the busbar system (6) has transverse current rails (19) extending between the cathode side and the anode side of the battery cell assembly, and that, viewed in the stacking direction (x), a transverse current rail (19) is arranged between adjacent battery cells (1), and that the transverse current rail (19) can be coupled or decoupled with one or both cathode arresters (3) of the two adjacent battery cells (1) by means of switching units (pin), and / or that the transverse current rail (19) can be coupled or decoupled with one or both anode arresters (5) of the two adjacent battery cells (1) by means of switching units (pin). [5] Battery cell assembly according to claim 4, characterized by, that the transverse current rail (19) is divided transversely to the stacking direction (x) into rail segments which can be electrically coupled or decoupled by means of at least one switching unit (pin), and / or that a battery cell (1) arranged at the end face of the battery cell assembly is connected with its cathode arrester (3) to a positive cell assembly terminal (21), and that the battery cell (1) arranged at the other end face of the battery cell assembly is connected with its anode arrester (5) to a negative cell assembly terminal (23). [6] Battery cell assembly according to one of claims 4 or 5, characterized by, that the transverse busbars (19) and the switching units (pin) are embedded in a U-shaped plastic component that surrounds the battery cell assembly from above, and that in particular the U-shaped plastic component is formed from a cathode busbar (7), an anode busbar (9) and a central busbar (11) connecting the cathode busbar (7) and the anode busbar (9), and that in particular the cathode busbar (7) has electrically insulated insert parts (13) which can each be electrically connected to a corresponding cathode arrester (3), and / or that the anode busbar (9) has electrically insulated insert parts (17) which can each be electrically connected to a corresponding anode arrester (5),and that, in particular in the stacking direction (x), a transverse current rail (19) is arranged between adjacent insert parts (13) of the anode busbar (9) and between adjacent insert parts (17) of the cathode busbar (7), and that, in particular, the insert parts (13, 17) form electrical contacts which can be electrically coupled to the transverse current rail (19) via the switching units (pin). [7] Battery cell assembly according to any one of the preceding claims, characterized by, that each of the switching units (pin) has a switching housing (25) with a stroke-adjustable switching element (27), and that in a deactivated state the switching units (pin) are in the decoupling position, and that in particular the switching element (27) of the respective switching unit (pin) is supported in the decoupling position by means of spring preload against a latch (31) in the locking position, and that when the latch (31) is moved into its release position the switching element (27) can be moved into its coupling position by means of the spring preload, in which the switching element (27) establishes an electrical coupling in the busbar system (6), and that in particular the latch (31) can be moved from its locking position to its release position by means of magnetic force, and that in particular by means of the activation device (37) depending on the circuit scheme (V) to be set soll) local magnetic fields can be generated with the help of which the latches (31) of predetermined switching units (pin) can be adjusted into the release position in order to bring their switching elements (27) into the electrically conductive coupling position. [8] Battery cell assembly according to any one of the preceding claims, characterized by , that the respective switching unit (pin) is designed as a connecting pin, and that the connecting pin (pin) is held on the activation device (37) before an activation step is carried out, and that in the activation step the connecting pin (pin) can be released by the activation device (37) and brought into a current-conducting coupling position in which electrical contacts (K1, K2) in the busbar system (6) are electrically closed. [9] Battery cell assembly according to claim 8, characterized by, that after the activation step a fastening step takes place in which the activated connecting pins can be permanently fixed in their coupling position, for example by welding or screw connection. [10] Method for manufacturing a battery cell assembly according to one of the preceding claims, wherein during the manufacturing process the switching units (pin) located in the battery cell assembly are in their decoupling position, i.e. deactivated, so that no circuit scheme is yet defined in the battery cell assembly, and wherein at the end of the manufacturing process an activation step takes place in which a circuit scheme to be set (V) is set by means of an external activation device (37). soll ) is determined in the battery cell assembly.

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