Process for producing a battery

Abstract

The invention relates to a method for producing a battery (2). A battery housing (14) is provided in which two spaced-apart attachments (16) for a cell stack (6) are arranged. The cell stack (10) is compressed in the X-direction (X) using pressure pieces (18) so that the cell stack (6) has a first predetermined length (L1) which is smaller than the distance (d) between the attachments (16). The cell stack (6) is introduced into the battery housing (14) between the attachments (16), wherein the pressure pieces (18) are received in the attachments (16). The pressure pieces (18) are then moved away from the cell stack (6) in the X-direction (X) so that the cell stack (6) rests against the attachments (16). The invention further relates to a device (4) for producing a battery (2) and to such a battery (2).

Description

[0001] The invention relates to a method for producing a battery, wherein a cell stack with battery cells is compressed and inserted into a battery housing. Furthermore, the invention relates to a device for producing the battery and to such a battery.

[0002] An electrically powered motor vehicle typically has a traction battery (high-voltage battery, HV battery) that supplies energy to an electric motor to drive the motor vehicle. An electrically powered motor vehicle is understood to mean, in particular, an electric vehicle that stores the energy required for propulsion solely in the traction battery (BEV, battery electric vehicle), an electric vehicle with a range extender (REEV, range extended electric vehicle), a hybrid vehicle (HEV, hybrid electric vehicle), a plug-in hybrid vehicle (PHEV, plug-in hybrid electric vehicle), and / or a fuel cell vehicle (FCEV, fuel cell electric vehicle), which temporarily stores the electrical energy generated by a fuel cell in the traction battery.

[0003] Such a traction battery, for example, a lithium-ion battery, a nickel-manganese-cobalt battery, or a lithium-ferrophosphate battery, comprises a number of interconnected battery cells. The battery cells are advantageously arranged next to one another to form a cell stack.

[0004] The battery cells, which are designed in particular as prismatic battery cells, are expediently subjected to pressure from the outside of the cell in the stacking direction of the cell stack, so that the battery cells are operated in an optimal pressure range.

[0005] In the so-called modular construction method, the battery cells or cell stack are inserted into a frame, which is then welded together. The resulting module is then inserted into a battery housing. Alternatively, the battery cells or cell stack are inserted between two pressure plates and clamped against each other. The two pressure plates are held together by a clamping band.

[0006] WO 2018 223 167 A1 discloses a method for installing a cell stack of battery cells into a housing of a battery module without prestressing. A sliding element is arranged on each outer side surface of the cell stack. The housing and the cell stack are moved relative to one another in the installation direction such that one end of the sliding element is first guided into the housing. The cell stack, including the sliding element, is then pushed into the housing, with the inner housing surface and an outer sliding surface of the sliding element facing away from the cell stack sliding relative to one another until the cell stack has reached its predetermined position in the housing.

[0007] DE 10 2020 003 882 A1 discloses an assembly device for assembling a battery. The assembly device comprises a base device with a base plate, retaining fingers, and two pressure plates for producing a cell pack, wherein the base plate has a groove on each of its longitudinal sides. The retaining fingers are each arranged displaceably in one of the two grooves and along the respective groove. The pressure plates are arranged displaceably in both grooves along the grooves via guide formations. Furthermore, the assembly device comprises a transfer device for removing the cell pack from the base device, wherein the transfer device is designed to be inserted into pockets in the bulkheads.

[0008] DE 10 2019 208 570 A1 relates to a battery assembly with a battery housing comprising a hollow profile strand with a tubular interior and at least one front-end loading opening. A plurality of electrochemical cells are arranged in said interior. The electrochemical cells are each provided with a plate-shaped cell housing with end faces and a peripheral housing edge, and are inserted into the interior of the battery housing with one end face first through the loading opening.

[0009] The invention is based on the object of providing a particularly suitable method for producing a battery. In particular, the component complexity for the battery should be reduced and / or production should be as simple as possible. Furthermore, a device for producing the battery, in particular according to the method, and such a battery should be provided.

[0010] With regard to the method, the object is achieved according to the invention by the features of claim 1. With regard to the device, the object is achieved according to the invention by the features of claim 6 and with regard to the battery by the features of claim 10.

[0011] Advantageous embodiments and further developments are the subject of the dependent claims. The statements made in connection with the method also apply mutatis mutandis to the device and the battery, and vice versa.

[0012] The process is used to manufacture a battery. The battery is, in particular, a traction battery (high-voltage battery) for an electrically powered motor vehicle.

[0013] In the method, a battery housing is first provided. The battery housing is in particular trough-shaped, in other words, the battery housing comprises in particular a base (housing base) and a housing frame extending perpendicular to the base. For example, the housing base comprises a cooling plate or is designed as a cooling plate. At most, the battery housing is intended and configured to accommodate a cell stack with battery cells. The cell stack comprises, expediently, prismatic battery cells that are arranged next to one another in a stacking direction. For example, a compression pad or a cell separation material is arranged between each two of the battery cells. The cell stack expediently also comprises two pressure plates between which the battery cells are arranged, in other words, one of the pressure plates is arranged on either side of the battery cells in the stacking direction.

[0014] For example, the battery cells are lithium-ion battery cells, in particular nickel-manganese-cobalt (NMC) or lithium-ferrophosphate (LFP) battery cells. However, the invention is also applicable to all other chemistry types that have analogous physical-mechanical properties.

[0015] In the battery housing, two systems for the cell stack are arranged, spaced apart from each other in the X direction.

[0016] The cell stack to be mounted in the battery housing is expediently first placed on a support. The cell stack is then compressed in the X-direction, particularly on the support, using pressure pieces, i.e., pressed using the pressure pieces, so that the cell stack has a first predetermined length. The first predetermined length is smaller than the distance between the components of the battery housing. For example, the first length is between 0.5 mm and 10 mm, in particular between 1 and 5 mm, for example, 3 mm smaller than the distance between the two components in the battery housing.

[0017] To compress the cell stack, the pressure pads can be moved in and / or against the X-direction. The cell stack is therefore arranged between the pressure pads, preferably in such a way that the X-direction is parallel to the stacking direction of the cell stack.

[0018] The cell stack is then inserted into the battery housing between the units. In other words, the cell stack is positioned between the units. For this purpose, for example, the cell stack is moved into the battery housing and / or the battery housing is moved onto the cell stack. The cell stack is suitably compressed to the first specified length using the pressure pieces. As the cell stack is inserted into the battery housing, the pressure pieces are received in the units, in particular, they are moved into them in a direction perpendicular to the X-direction. The pressure pieces therefore protrude into the unit toward the bottom of the battery housing.

[0019] In summary, the cell stack is arranged between the systems, whereby the cell stack is arranged at a distance from one of the systems or from both systems due to its compression to the first length in the X direction, i.e. in the stacking direction.

[0020] The pressure pads are then moved away from the cell stack in the X-direction. In other words, the pressure pads are moved apart. The pressure pads are still held within the respective system. In other words, the pressure pads move away from the cell stack within the respective system. The cell stack relaxes (i.e., expands in the X-direction), so that the cell stack rests against the systems and is clamped between them. The cell stack is then spaced from the pressure pads, meaning it is no longer in contact with them.

[0021] It is then advisable to move the pressure pieces out of the battery housing, particularly in a direction perpendicular to the housing base.

[0022] In summary, the systems are designed in such a way that the respective pressure piece can be moved into and out of the system both in the X-direction in the support away from the cell stack and in a direction perpendicular to the housing base.

[0023] In the final assembly state of the battery, the cell stack is clamped between these two devices and, in particular, rests directly against them. The battery cells of the cell stack are thus already subjected to pressure by the devices. This advantageously eliminates the need for a module housing or frame, nor for clamping the battery cells.

[0024] In summary, a battery is manufactured using cell-to-pack construction.

[0025] Particularly preferably, the compression of the cell stack is force-monitored and / or pressure-monitored in an analogous manner. Particularly preferably, the compression is force-displacement-monitored. In other words, when compressing the cell stack, the force applied for this purpose using the pressure pieces or the pressure acting on the cell stack is recorded, in particular for the respective distance between the pressure pieces. The compression is expediently carried out in such a way that a predetermined maximum force or a predetermined maximum pressure for compressing the cell stack is not exceeded in order to avoid damage to the cell stack. For example, the maximum pressure or the maximum force depends on the distance between the pressure pieces. Additionally or alternatively, a force or pressure range is predetermined for the operation of the cell stack, in particular on the end faces of the cell stack facing the systems.If a force or pressure is exerted on the cell stack by means of the pressure pieces that is not within this specified range, when the cell stack is compressed by the pressure pieces to a length that corresponds to the distance between the two systems, further action will be taken, in particular a notice will be given to the user and / or this cell stack will not be used for the battery.

[0026] According to an advantageous embodiment, the cell stack is positioned relative to the battery housing prior to compressing the cell stack to the first predetermined length, so that the pressure pieces are arranged above or below the devices in a direction perpendicular to the housing base. For example, the cell stack is compressed to a length that corresponds to the distance between the two devices. The distance between the two devices is also referred to as the nominal dimension.

[0027] In summary, the battery housing is pre-positioned relative to the cell stack. This results in a comparatively short path for the cell stack (subsequently compressed to the first length) into the battery housing. This also reduces the time during which the cell stack is compressed, especially to the first length. In particular, inserting the cell stack only requires moving the cell stack relative to the battery housing in a direction perpendicular to its base.

[0028] According to an advantageous embodiment of the method, an adhesive, in particular a layer of adhesive, is or will be applied to a bottom of the battery housing.

[0029] Preferably, the cell stack compressed to the first predetermined length is first introduced into the battery housing such that it is spaced apart from the adhesive. For example, the distance between the adhesive and the cell stack is between 3 mm and 5 mm. The cell stack is then relaxed to a second predetermined length. The second predetermined length is shorter than the distance between the receptacles and longer than the first predetermined length. For example, the second length is between 0.1 mm and 1 mm, in particular between 0.25 mm and 0.75 mm, for example 0.5 mm shorter than the distance between the two systems. For this purpose, in particular the distance between the two pressure pieces is increased accordingly by a displacement movement away from each other in the X direction.A force acting on the cell stack by means of the pressure pieces is therefore reduced accordingly (compared to the force for compression to the first specified length), so that the cell stack expands in the X-direction.

[0030] Subsequently, and expediently before the pressure pieces are moved away from the cell stack in the X-direction, the cell stack and the base are pressed against each other. The cell stack is thus pressed into the adhesive, wherein the cell stack in particular has the second predetermined length. In this way, any expansion of the cell stack during the movement (movement) of the pressure pieces away from it and the associated expansion of the cell stack until it rests against the systems is advantageously comparatively small. The adhesive is therefore deformed comparatively little during this expansion, so that warping of the adhesive and any associated risk of a reduction in adhesive strength is avoided or at least reduced.

[0031] According to an advantageous embodiment of the method, the cell poles of the battery cells of the cell stack are electrically connected to one another prior to the cell stack being inserted into the battery housing. Thus, the cell poles are expediently interconnected in a predetermined manner using cell connectors. For example, the cell connectors are mounted on a common frame arranged on one of the end faces of the cell stack containing the cell poles.

[0032] The electrical interconnection of the battery cells takes place outside the battery housing. Advantageously, the space for the assembly process of the cell connectors is comparatively large.

[0033] Preferably, the cell stack is compressed to the second specified length or to the nominal dimension using the cell connectors before connecting the cell terminals. The cell terminals are then connected at the length the cell stack has in its final assembly state. Consequently, mechanical stresses in the joining of the cell connectors to the cell terminals are avoided or at least reduced.

[0034] According to an advantageous embodiment of the method, the battery housing is moved in the hat position onto the cell stack compressed, in particular by means of the pressure pieces, so that the cell stack is arranged in the battery housing between the systems and / or so that the pressure pieces are received in the receptacles.

[0035] The top-end position of the battery housing refers to the orientation of the battery housing such that it is open downwards, i.e., in a direction counter to gravity. In other words, the side walls of the battery housing extend downwards from its base in the top-end position. The cell stack can therefore be inserted into the battery housing from below, and / or the battery housing can be applied to the cell stack from above.

[0036] To insert the cell stack into the battery housing, it is not necessary, and preferably, removed from the support. The cell stack remains in place on the support. This eliminates the need for an additional holding element, such as a suction unit, to prevent the cell stack from bending during insertion into the housing.

[0037] The top-hat position advantageously allows for additional, similarly compressed cell stacks to be inserted into the battery housing simultaneously. For this purpose, these additional cell stacks are arranged and compressed accordingly on the support. The battery housing is then placed on top of the cell stacks.

[0038] For example, after the cell stack has been inserted into the battery housing, it is rotated together with the battery housing, and thus the support is rotated together with the battery housing, around a common axis (rotational axis) so that the battery housing is open at the top. The pressure pieces can then be moved upwards out of the battery housing.

[0039] A further aspect of the invention relates to a device for producing a battery, in particular a traction battery for an electrically powered motor vehicle. The device is suitably provided and configured so that the method described above can be and / or is carried out using this device.

[0040] For this purpose, the device comprises a support for a cell stack. The support defines a support surface, in particular a support plane, on which the cell stack can be arranged.

[0041] The device further comprises pressure pieces for compressing the cell stack to a predetermined length. The pressure pieces can be moved toward each other in a direction referred to as the X-direction. The support is expediently configured so that the cell stack is arranged between the pressure pieces, with the X-direction corresponding to a stacking direction of the cell stack, thus a direction from one of its battery cells to another of its battery cells. In other words, the X-direction is parallel to the stacking direction.

[0042] Each of the pressure pieces has fingers oriented perpendicular to the support, in particular to the support surface formed by the support piece, and in particular projecting upwards therefrom. The respective pressure piece expediently comprises at least two fingers, in particular between two and ten fingers.

[0043] The fingers extend in a direction perpendicular to the X-direction. This direction is also referred to as the Z-direction. The fingers are spaced apart from one another, particularly in a direction (Y-direction) perpendicular to the X-direction and the Z-direction. As already described in connection with the method, this allows the fingers to move into the respective system of the battery housing and then away from the cell stack in the X-direction. The fingers thus correspond to the shape of the respective system.

[0044] According to a suitable embodiment of the device, the support is formed by two support elements that can be moved into one another, particularly in the X direction. For example, each of the support elements is formed by arms extending in the X direction and spaced apart from one another in the Y direction, with the arms of one of the support elements being arranged offset in the Y direction from the arms of the other support element.

[0045] For example, one of the support elements is arranged on each of the pressure pieces. In particular, one of the support elements is fixed to each of the pressure pieces on the side facing the other pressure piece, i.e., rigidly joined to it. When the cell stack is compressed, the respective support element moves together with the pressure piece attached to it.

[0046] According to a practical embodiment, the device further comprises a holding device, e.g., designed as a gripper, for holding and / or moving the battery housing. According to a first variant of the device, the holding device and the support 8, and preferably also the pressure pieces, are preferably rotatable about a common axis (rotational axis), which is expediently oriented parallel to the X-direction.

[0047] As already described in connection with the method, this advantageously makes it possible for the battery housing to be moved in the hat position onto the compressed cell stack and for the cell stack to then be rotated together with the battery housing about this common axis so that the battery housing is open at the top.

[0048] In particular, the cell stack is not inherently rigid. When the cell stack is lifted using the pressure pieces, there is a risk that the battery cells located centrally within the cell stack will sag downwards or that cells will even detach from the stack and fall down. According to a suitable embodiment of the device, which is particularly an alternative to the first variant of the device, it therefore comprises a suction unit for sucking the battery cells from the cell stack. The suction unit is particularly preferably movable together with the pressure pieces.

[0049] The suction unit is designed to suction the battery cells of the cell stack, preventing downward deflection of the cell stack when the cell stack is lifted from the support (where the cell stack is compressed, in particular, by the pressure pieces) and transferred into the battery housing, which is preferably open at the top. The suction unit is thus designed to hold the battery cells of the cell stack in a position relative to the pressure pieces.

[0050] A further aspect of the invention relates to a battery that was produced according to one of the variants of the method described above and / or using the device in one of the device variants described above. The battery is, in particular, a traction battery for an electrically powered motor vehicle. The battery therefore comprises a battery housing, in particular a trough-shaped one, wherein two systems spaced apart from one another in the X direction are arranged in the battery housing. A cell stack is arranged between the systems, wherein the cell stack preferably rests directly, i.e., immediately, against the systems, and / or wherein the systems exert pressure on the cell stack. In particular, the stacking direction of the battery cells of the cell stack corresponds to the X direction. In particular, no module housing separate from the battery housing or no frame for the cell stack is provided. In other words, the battery is designed in a cell-to-pack design.

[0051] The attachments are each designed such that they are open in a direction oriented perpendicular to and away from a bottom of the battery housing, and in the X-direction toward the cell stack. Each of the attachments is expediently formed from at least two ribs that extend in a direction perpendicular to the bottom of the battery housing and / or are spaced apart from one another in a direction perpendicular to the X-direction and parallel to the bottom of the battery housing.

[0052] The cell stack is conveniently joined to the bottom of the battery housing using an adhesive.

[0053] A further aspect of the invention relates to a motor vehicle, in particular an electrically powered one, having a battery in one of the variants described above. The battery is in particular a traction battery (high-voltage battery) that provides electrical energy for a high-voltage electrical system of the motor vehicle and / or for a drive, in particular for its traction electric motor, of the motor vehicle. The voltage provided by the battery is expediently between 60 V and 1500 V.

[0054] In the following, exemplary embodiments of the invention are explained in more detail with reference to a drawing. In the drawings: Fig. 1a shows a first variant of a method for producing a battery using a flow chart, Fig. 1b shows a flow chart of a second variant of the process for producing the battery, Fig. 2a to 2e schematically show a cell stack and a battery housing after different assembly steps according to the first variant of the method, wherein the battery housing is oriented in the top hat position for the insertion of the cell stack, Fig. 3a to 3d schematically show the cell stack and the battery housing after different assembly steps according to the second variant of the method, wherein the battery housing is oriented in a tray position for the insertion of the cell stack, Fig. 4a schematically shows in a longitudinal section the battery housing with the cell stack inserted therein, wherein the cell stack is compressed by means of pressure pieces to a length which is smaller than the distance between the systems for the cell stack arranged in the battery housing, and wherein the pressure pieces are moved into the systems, Fig. 4b schematically shows in perspective view the battery housing with the cell stack inserted therein according to the Fig. 4a, Fig. 4c schematically shows a longitudinal section of the battery housing with the cell stack inserted therein, with the pressure pieces being moved away from the cell stack into a free-running position, Fig. 4d schematically shows in perspective the battery housing with the cell stack inserted therein, with the pressure pieces being moved out of the systems, and Fig. 5 schematically shows an apparatus for producing the battery according to the first variant of the method.

[0055] Corresponding parts and sizes are always provided with the same reference symbols in all figures.

[0056] In the Fig. 1a shows a flowchart that represents a method for producing a battery 2 according to a first method variant. A device 4 for producing a battery 2, i.e., a device 4 by means of which the method according to the first variant can be carried out, is shown in Fig. 2a to 2e schematically and in the Fig. 5. In a first step 1a, a cell stack 6 is placed on a support 8. The cell stack 6 (stack 6) comprises battery cells 10 stacked one behind the other in a direction referred to as the stacking direction, between which a compression pad (not further shown) is preferably arranged. A pressure plate 12 is preferably arranged at the end of the stack and at the beginning of the stack.

[0057] Furthermore, in step 1a, a battery housing 14, designed here as a battery tray, is provided, into which the cell stack is to be inserted. Two spaced-apart attachments 16 are arranged in the battery housing 14, between which the cell stack 6 is to be inserted in such a way that it directly rests against the attachments 16 and is subjected to pressure by the attachments 16, thus being held clamped between the attachments 16. The distance between the two attachments 16 is designated by the reference symbol "d."

[0058] In a subsequent step IIa, the cell stack 6 is compressed, i.e. pressed, on the support 8 using pressure pieces 18, so that the cell stack 6 has a length in the stacking direction that corresponds to the distance d between the two systems 16. The distance between the two pressure pieces 18 is designated by "b" in the figures. Thus, after this step, d = b. For this purpose, the pressure pieces 18 are moved towards each other in a direction designated as the X direction X. The stacking direction of the cell stack 6 is parallel to the X direction. The cell stack 6 compressed using the pressure pieces 18 is shown schematically in the Fig. 2a.

[0059] Subsequently, in a step IIIa, the battery cells 10 of the cell stack 6 are electrically interconnected. For this purpose, the cell terminals 20 of the battery cells 10 are contacted in a predetermined manner using cell connectors 22. In particular, the cell connectors 22 are each welded to the respective cell terminals 20. The cell terminals 20 are thus connected to one another before the cell stack 6 is inserted into the battery housing 14.

[0060] Following this or simultaneously with one of steps 1a to 111a, in step IVa the battery housing 14 is (pre-)positioned with respect to the cell stack 6 and thus with respect to the support 8. For this purpose, the battery housing 14 is held and / or moved accordingly by a corresponding holding device 24. According to the first variant of the method, the battery housing 14 is positioned in the hat position above the cell stack 6, so that the cell stack 6 is arranged between the support 8 and the battery housing 14. The battery housing 14 is positioned such that the cell stack 6 is arranged below the battery housing 14 in a direction perpendicular to the support 8 (Z direction) and / or perpendicular to a base 26 of the battery housing 14.The battery housing 14 and the cell stack are aligned such that the cell stack 6 is arranged below the space between the two systems 16 arranged in the battery housing, wherein the X-direction X is oriented parallel to a direction from one of the systems 16 to the other system 16. The cell stack is and / or remains expediently compressed during pre-positioning to a length corresponding to the distance b. In summary, in this state, the pressure pieces 18 are arranged below the systems 16 with respect to the Z-direction. In the . Fig. Figure 2b schematically shows the battery housing 14 pre-positioned in the top position with respect to the cell stack.

[0061] Subsequently, in step Va, the cell stack 6 is further compressed using the compression members 18 to a first predetermined length L1 (first length L1) in the X-direction X. The value of the first length L1 is therefore smaller than the distance d between the two units 16. For example, the length L1 of the cell stack 6 is between 2 mm and 5 mm, in particular 3 mm smaller than the distance d between the two units 16. In summary, after this compression, the cell stack 6 has the length L1.

[0062] Subsequently, in step V1a, the battery housing 14 is lowered towards the support 8. In the process, the cell stack 6 is inserted between the devices 16 arranged in the battery housing 14. The pressure pieces 18 are received in the devices in the course of this. In other words, the pressure pieces 18 are moved in the Z-direction Z into the devices 16. The lowering of the battery housing 14, thus the insertion of the cell stack 6 into it, takes place in step V1a such that the cell stack 6, compressed to the first predetermined length L1, is spaced from an adhesive 28 applied to the base 26, in particular to the inside of the housing. For example, the distance "c" after step V1a is between 3 mm and 5 mm. In the Fig. Figure 2c schematically shows the cell stack 6 inserted into the battery housing 14, spaced from the adhesive 28 applied to the base 26. Due to the compression of the cell stack 6 to the length L1, there is sufficient space for arranging the cell stack between the devices 16.

[0063] For this purpose, the attachments 16 and the pressure pieces have corresponding shapes. As shown in particular in the Fig. 4a to 5, each of the pressure pieces comprises at least two, according to the embodiments of the Fig. 4a to 4d five, and in the variant of the Fig. 5 has six fingers 30 which are arranged parallel to one another and extend in the Z direction, i.e. perpendicular to the support 8. The fingers 30 are spaced from one another in a direction referred to as the Y direction Y, perpendicular to the X direction and to the Z direction. With regard to the X direction, the fingers 30 are aligned with one another. The respective receptacle 16 comprises a number of ribs 32 which extend in a direction perpendicular to the bottom of the battery housing 14. According to the exemplary embodiment shown here, the ribs 32 are spaced from one another in such a way that one of the fingers 30 of the respective pressure piece can be received between two adjacent ribs 32. For example, the ribs 32 are connected to one another by means of a connecting leg 34 at their end facing the bottom 26 and / or at their end facing away from the respective other support 16.At most, the receptacle formed between the ribs 32 for the respective finger 30 is open in the direction from the floor 26 and perpendicular to it, as well as in a direction toward the other system, i.e., toward the space for the cell stack 6. The extension of the fingers 30 in the X direction is smaller than the extension of the ribs 32 in a direction from one of the systems 16 to the other system 16.

[0064] Subsequently, in step V1a, the pressure pieces 18 are moved apart so that the cell stack has a second predetermined length L2 (second length L2). For this purpose, the pressure pieces 18 are moved apart such that their distance from one another corresponds to the second length L2. The amount of the second length L2 is smaller than the distance d between the two systems 16 and greater than the first length. For example, the second length is 0.5 mm smaller than the distance between the two systems 16. The cell stack 6 with the second length L2 is moved into the adhesive 28 and pressed against the base 26, in particular such that the base 26 and the cell stack 6 have a predetermined distance from one another. In summary, the cell stack 6 is glued to the base 26.

[0065] Subsequently, in step VIIa, the two pressure pieces 18 are moved apart. The cell stack 6 decompresses, i.e., expands in the X-direction X until it rests directly against the attachments 16 and is clamped between them with a length b. The two pressure pieces 18 are moved away from the cell stack 6 with respect to the X-direction X, so that with respect to the X-direction, a gap S is formed both between the cell stack 6 and the respective pressure piece 18 and a gap S between the pressure piece 18 and the battery housing 14 or the connecting leg 34. This position of the respective pressure piece 18 is also referred to as the release position. The pressure pieces therefore move in the area between the ribs 32. The Fig. 2d schematically shows the cell stack 6 pressed against the base 26, wherein the cell stack 6 is clamped between the systems 16 arranged in the battery housing 14.

[0066] Subsequently, in step VIIIa, the cell stack 6 and the battery housing 14 are turned so that the battery housing 14 is open at the top. For this purpose, the support 8 and the holding device 24 are rotated about a common (rotational) axis D, which is preferably oriented parallel to the X-direction X. Subsequently, the pressure pieces 18 are removed from the battery housing 14 and thus from the systems 16. For example, the battery housing 14 and the cell stack 6 accommodated therein are moved away from the support, in particular downwards. Fig. 2e schematically shows the cell stack 6 and the battery housing 14, which are rotated together about the rotation axis D.

[0067] The battery housing 14 of the battery 2 thus formed is expediently closed with a lid in a manner not shown in detail.

[0068] In the Fig. 1b shows a flowchart that represents a method for producing a battery 2 according to a second method variant. A device 4 for producing a battery 2, i.e., a device 4 by means of which the method according to the second variant can be carried out, is shown in Fig. 2a to 2e are shown schematically. In a first step 1b, the cell stack 6 to be inserted into the battery housing 14 is placed on the support 8, see also Fig. 3a.

[0069] Furthermore, in step 1b, the battery housing 14, which is designed here as a battery tray, is provided, wherein the two spaced-apart systems 16 are arranged in the battery housing 14.

[0070] In a subsequent step IIb, the cell stack 6 is compressed on the support 8 using the pressure pieces 18, so that the cell stack 6 has a length in the stacking direction that corresponds to the distance d between the two systems 16. For this purpose, the pressure pieces 18 are moved toward each other in the X direction X. The stacking direction of the cell stack 6 is parallel to the X direction.

[0071] Subsequently, in a step IIIb, the battery cells 10 of the cell stack 6 are electrically interconnected. For this purpose, the cell poles 20 of the battery cells 10 are contacted in a predetermined manner using cell connectors 22.

[0072] Subsequently, in step IVb, the cell stack 6 is (pre-)positioned with respect to the battery housing 14, see also Fig. 3b. For this purpose, the cell stack 6 is lifted from the support 8, which here is designed as a table, for example, and arranged above the battery housing 14. The battery housing 14 and the cell stack 6 are aligned such that the cell stack 6 is arranged above the space between the two systems 16 arranged in the battery housing 14. During the pre-positioning process, the cell stack is and / or remains compressed to a length corresponding to the distance b. For this purpose, the device 4 comprises a suction unit 36, which is designed to suck in the battery cells 10 of the cell stack and to hold them during removal from the support 8. The suction unit 36 ​​and the pressure pieces together form a gripper 38, by means of which the cell stack 6 can be inserted from the support into the battery housing 14.

[0073] Subsequently, in step Vb, the cell stack 6 is further compressed by means of the pressure pieces 18 to the first predetermined length L1 with respect to the X-direction X. The value of the first length L1 is therefore smaller than the value of the distance d between the two systems 16. As in the method according to Fig. 1a, the length L1 of the cell stack 6 is, for example, between 2 mm and 5 mm, in particular 3 mm smaller than the distance d between the two systems 16. In summary, the cell stack 6 has the length L1 after this compression.

[0074] Subsequently, in step VIb, the cell stack is introduced into the battery housing 14; in particular, for this purpose, the cell stack 6 is lowered into the battery housing 14. In the process, the cell stack 6 is thus introduced between the systems 16 arranged in the battery housing 14. The pressure pieces 18 are received in the systems 8 in the course of this. The introduction of the cell stack 6 into the battery housing takes place in step VIb such that the cell stack 6, compressed to the first predetermined length L1, is spaced from the adhesive 28 applied to the base 26, in particular to the inside of the housing, cf. Fig. 3c.

[0075] In an analogous manner to the device 4 for producing the battery according to the first variant, the systems 16 and the pressure pieces 18 have mutually corresponding shapes, see also Fig. 4a to 4d. Thus, the pressure pieces 18 comprise fingers 30, and the receptacles comprise corresponding ribs 32. The fingers extend upwards in a direction perpendicular to the suction device 36.

[0076] Subsequently, in step VIb, the pressure pieces 18 are moved apart so that the cell stack has the second predetermined length L2 (second length L2). For this purpose, the pressure pieces 18 are moved apart in such a way that their distance from one another corresponds to the second length L2. The amount of the second length L2 is smaller than the distance d between the two systems 16 and greater than the first length L1. For example, the second length is 0.5 mm smaller than the distance between the two systems 16. The cell stack 6 with the second length L2 is moved into the adhesive 28 and pressed against the base 26, in particular in such a way that the base 26 and the cell stack 6 have a predetermined distance from one another. In summary, the cell stack 6 is glued to the base 26, cf. Fig. 3d.

[0077] Subsequently, in step VIIb, the two pressure pieces 18 are moved apart. The cell stack 6 decompresses, i.e., expands in the X direction X until it rests directly against the attachments 16 and is clamped between them with a length b. The two pressure pieces 18 are moved away from the cell stack 6 with respect to the X direction X, so that, with respect to the X direction, a gap S is formed both between the cell stack 6 and the respective pressure piece 18 and a gap S between the pressure piece 18 and the battery housing 14 or the connecting leg 34. The pressure pieces 18 thus move in the area between the ribs 32.

[0078] Subsequently, in step VIIIb, the pressure pieces are removed from the battery housing 14. The gripper 38 is moved away from the cell stack 6 and the pressure pieces are removed from the devices 16.

[0079] The battery housing 14 of the battery 2 thus formed is then expediently closed with a lid in a manner not shown in detail.

[0080] In both process variants, the compression of the cell stack 6 is preferably carried out in a force-monitored manner or, particularly preferably, in a force-displacement-monitored manner.

[0081] In the Fig. 4a and Fig. Figure 4b shows a schematic and partial view of the cell stack 6 arranged in the battery housing 14 according to steps VIa, VIb, wherein the respective pressure piece 18 is received in the respective attachment 16. The cell stack 6 has a length L2.

[0082] In the Fig. 4c shows a schematic and partial view of the cell stack 6 arranged in the battery housing 14 according to steps VIIa, VIIb, wherein the cell stack is clamped between the attachments 16, and wherein the respective pressure piece 18 is arranged in the free-moving position, i.e. wherein the pressure pieces 18 are arranged at a distance from the cell stack in the X direction, forming the gap S.

[0083] In the Fig. 4d shows schematically and in detail the pressure piece 18 moved out of the battery housing 14 according to steps VIIIa, VIIIb. In the Fig. Figure 4d particularly shows the design of one of the systems 16 with ribs 32, i.e., as a rib structure. The ribs 32 are arranged in such a way that the fingers 30 of the respective pressure piece can be moved between the ribs 32, both in a direction perpendicular to the base 26 and from the cell stack 6.

[0084] In the Fig. Figure 5 schematically shows a variant of the device 4 for producing the battery according to the first variant. Here, the support 8 is formed by two support elements 8a, 8b that can be moved into one another in the X direction. Each of the support elements 8a, 8b in turn comprises arms 40 that extend in the X direction and are spaced apart from one another in the Y direction. The arms 40 of one of the support elements 8a are arranged offset in the Y direction from the arms 40 of the other support element 8b.

[0085] According to the exemplary embodiment shown here, one of the support elements 8a, 8b is arranged and fixed to one of the pressure pieces 18, namely on the side facing the other pressure piece 18. Thus, when compressing the cell stack 6, the respective support element 8a, 8b is moved in the X direction together with the pressure piece 18 fixed to it.

[0086] Alternatively, support 8 is designed as a table.

[0087] The holding device 24 for the battery housing 14 is only indicated schematically and is designed, for example, as a gripper. As shown in the Fig. As shown in Figure 2e, the holding element 24 and the support 8 and preferably additionally the pressure pieces are rotatable about a common axis of rotation D.

[0088] The invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can be derived from them by those skilled in the art within the scope of the claims without departing from the subject matter of the invention. In particular, all individual features described in connection with the exemplary embodiments and / or in the claims can also be combined with one another in other ways without departing from the subject matter of the invention. List of reference symbols 2 batteries 4 Device 6 cell stacks 8th edition 8a first support element 8b second support element 10 battery cells 12 printing plate 14 Battery housing 16 Appendix 18 Pressure piece 20 cell pole 22 cell connectors 24 Holding device 26 Bottom of the battery case / case bottom 28 adhesives 30 fingers 32 ribs 34 connecting legs 36 Suction unit 38 grippers 40 arms b Distance between the pressure pieces c Distance of the cell stack to the adhesive d Distance between the systems / nominal dimension D axis of rotation L1 first specified length for the cell stack L2 second specified length for the cell stack S gap X X-direction Y Y-direction Z Z-direction Ia Provision of the cell stack and the battery housing IIa Compressing the cell stack IIIa Connecting the battery cells IVa Pre-positioning Va Compressing the cell stack Vla Inserting the cell stack into the battery housing VIIa Clamping the cell stack between the systems VIIIa Turning the battery case Ib Provision of the cell stack and the battery housing IIb Compressing the cell stack IIIb Connecting the battery cells IVb Pre-positioning Vb Compress the cell stack VIb Inserting the cell stack into the battery housing VIIb Clamping the cell stack between the systems VIIIb Removing the pressure pieces from the battery housing QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] WO 2018 223 167 A1

[0006] DE 10 2020 003 882 A1

[0007] DE 10 2019 208 570 A1

[0008]

Claims

[1] Method for producing a battery (2), in particular a traction battery for an electrically powered motor vehicle, - wherein a battery housing (14) is provided in which two spaced-apart systems (16) for a cell stack (6) are arranged, - wherein the cell stack (10) is compressed in the X-direction (X) by means of pressure pieces (18) so that the cell stack (6) has a first predetermined length (L1) which is smaller than the distance (d) between the systems (16), - wherein the cell stack (6) is introduced into the battery housing (14) between the attachments (16), wherein the pressure pieces (18) are received in the attachments (16), and - wherein the pressure pieces (18) are moved away from the cell stack (6) with respect to the X-direction (X), so that the cell stack (6) rests against the systems (16). [2] Method according to claim 1, characterized bythat before compressing the cell stack (6) to the first length (L1), the cell stack is positioned relative to the battery housing (14) so ​​that the cell stack (6) is arranged between the support (8) and the battery housing (14). [3] Method according to claim 1 or 2, characterized by , - that an adhesive (28) is applied to a base (26) of the battery housing (14), and / or - that the cell stack (6) compressed to the first predetermined length (L1) is first introduced into the battery housing (14) in such a way that it is spaced from the adhesive (28), - wherein the cell stack (6) is subsequently relaxed to a second predetermined length (L2) which is smaller than the distance (d) and greater than the first predetermined length (L1), and - wherein subsequently, and in particular before the pressing pieces (18) are moved away from the cell stack, the cell stack (6) and the base (26) are pressed against one another. [4] Method according to one of claims 1 to 3, characterized by that cell poles (20) of the battery cells (10) are electrically connected to one another before the cell stack (6) is inserted into the battery housing (14). [5] Method according to one of claims 1 to 4, characterized by that the battery housing (14) is moved in the hat position onto the compressed cell stack (6) so that the cell stack (6) is received in the battery housing (14) between the systems (16). [6] Device (4) for producing a battery (2), in particular according to the method according to one of claims 1 to 5, comprising - a support (8) for a cell stack (6), - pressure pieces (18) movable towards each other in the X-direction (X) for compressing the cell stack (6) to a predetermined length, characterized by that the pressure pieces (18) are each oriented perpendicular to the support (8) and have fingers (30) spaced apart from one another. [7] Device (4) according to claim 6, characterized by , - that the support (8) is formed by two support elements (8a, 8b) which can be moved into one another, in particular in the X-direction (X), and / or - wherein one of the support elements (8a, 8b) is arranged on one of the pressure pieces (18). [8] Device (4) according to claim 6 or 7, characterized by a holding device (24) for holding a battery housing (14), and / or wherein the holding device (24) and the support (8) are rotatable about a common axis (D), which is oriented in particular parallel to the X-direction (X). [9] Device (4) according to claim 6 or 7, characterized by a suction unit (36) for sucking the cell stack (6) for removing it from the support (8). [10] Battery (2), in particular traction battery for an electrically driven motor vehicle, produced according to the method according to one of claims 1 to 5 and / or by means of the device according to one of claims 6 to 9.

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