Method for connecting a capture to a pole cap of a battery cell

Abstract

The invention relates to a method for connecting a trap (20) to an inner side (11) of a pole cap (10) of an electrochemical cell (100), in which a drawing mandrel (30) is pushed through an opening (12, 12 ') of the pole cap (10) and / or through an opening (23) or a recess (24) of the trap (20), the drawing mandrel (30) is designed to at least temporarily form a mechanical connection between the drawing mandrel (30) and the catch (20) at a portion (31 ''), or the drawing mandrel (30) is mechanically connected to the catch (20), in which a force (F) outward from the opening (12) of the pole cap (10) acts on the drawing mandrel (30) and the catch (20) presses against the inner side (11) of the pole cap (10), in which the catch (20) pressed against the inner side (11) of the pole cap (10) is connected to the pole cap (10), in particular in an electrically conductive manner.

Description

[0001] The present invention relates to a method for connecting a catcher (albeiter) to the inner side of a pole cap of an electrochemical cell.

[0002] In the production of electrochemical storage devices (such as lithium-ion batteries), for example, a number of alternating layers of anodes, cathodes, and separators are usually arranged in the form of a battery stack. The corresponding anodes and cathodes are electrically contacted through corresponding catchers. When using two battery stacks, for example, a U-shaped catcher is used, where two ends face the two battery stacks and the front faces the inner side of the pole cap. The catcher serves as an electrical interface between the battery stack and the pole cap.

[0003] Since the pole caps are arranged on both sides or opposite each other, the first pole cap can be conventionally welded or brazed to the catcher of the battery stack without technical challenges. The second pole cap can no longer be directly connected to the catcher. For this purpose, a longer connecting wire must be provided between the second catcher and the battery stack, which means that the longer connecting wire resulting from the assembly requires additional housing volume.

[0004] Therefore, the object of the present invention is to create a method for connecting a catcher (especially the second catcher to be connected), where the volume of the battery housing can be minimized. This object is achieved by the features specified in claim 1. Further advantageous embodiments of the present invention are part of the dependent claims.

[0005] According to one aspect of the present invention, a method for connecting a catcher to the inner side of a pole cap of an electrochemical cell is provided.

[0006] In one step, a draw mandrel is pushed through an opening (such as a filling opening) of the pole cap and / or through an opening or groove of the catcher. The opening of the catcher can be designed to correspond to the opening of the pole cap. Depending on the design of the draw mandrel, if the draw mandrel is mechanically or integrally connected to the catcher, the opening of the catcher does not need to be considered.

[0007] The draw mandrel can expand at the end of the catcher or be mechanically connected to the catcher to form at least a temporary mechanical connection between the draw mandrel and the catcher. Depending on the design, the draw mandrel can be permanently connected to the catcher at the end or can be connected.

[0008] In another step, a force outward from the filling opening of the pole cap is applied to the draw mandrel. This presses the catcher against the inner side of the pole cap. By pressing or pulling the catcher against the inner side of the pole cap, the initial gap between the inner side of the pole cap and the catcher can be eliminated, thus optimally preparing for subsequent connection steps. In the connection step, the catcher is then connected to the pole cap, especially in a conductive manner.

[0009] The method can be used to set a so-called zero gap between the pole cap and the catch, in order to achieve a reliable connection of the process between the pole cap and the catch. In particular, the method can be used to pull or push the catch against the pole cap from the outside, without applying any destructive force on at least one battery stack connected to the catch.

[0010] Furthermore, since the connection between the catch and the battery stack does not require additional length, the method can be used to minimize the need for additional battery volume.

[0011] According to one embodiment, the pulling mandrel moves outward through an opening in the catch. In the region of the opening, the pulling mandrel is mechanically hooked to the catch at the end, in particular in a form-fitting manner. Alternatively, the pulling mandrel is inserted through the openings of the pole cap and the catch, and in the region of the catch opening, it expands at the end mechanically or by overpressure, in particular pneumatically or hydraulically, or by vacuum, to form a temporary or permanent mechanical connection between the pulling mandrel and the catch. The end of the pulling mandrel can be expanded in various ways to lock the catch in place and thereby make it immovable relative to the pulling mandrel in at least one direction. By design, the pulling mandrel can be hooked to the catch or form a temporary fixed connection with the catch so that the catch can be moved against the pole cap. Thus, the pulling mandrel can expand or dilate in the opening or groove of the catch or after or below the opening to be able to move the catch in at least one direction.

[0012] The pulling mandrel can be expanded at the end in such a way that the end portion deforms and acts as a rivet, so to speak, to form a mechanical connection between the pole cap and the catch.

[0013] In particular, the pulling mandrel can be designed to pull the catch and thereby press it against the inner side of the pole cap or move the catch against the inner side of the pole cap.

[0014] According to another embodiment, the pulling mandrel has an outer tube portion, and the outer tube portion has an end expansion portion. Preferably, the expansion portion expands in at least some regions by the action of overpressure on the tube portion or by press-fitting a bolt. This allows the pulling mandrel to expand at the end in a technically simple manner. In this case, the expansion portion can be designed to be elastic in at least some regions to increase or decrease the dimension of the pulling mandrel transverse to the pulling direction of the catch. The pulling mandrel can be used as a tool with which the expansion portion of the pulling mandrel expands temporarily. In an alternative or additional design, the pulling mandrel can be used as a connecting device with which the expansion portion of the pulling mandrel can expand permanently.

[0015] If the expansion part has an expansion element and the expansion element is mechanically or vacuum-pulled or pressed into the outer tube part to expand the expansion part in at least some areas, the pulling mandrel can be of a particularly simple technical design. Accordingly, the expansion element can be separated from the outer tube part by mechanical action or by overpressure to reduce the size of the expansion part again. Depending on the design, a return spring can be provided, which can automatically space the expansion element from the outer tube part in the pulling direction of the pulling mandrel to reduce the size of the expansion part.

[0016] The expansion part can be expanded by the expansion element in at least one spatial direction transverse to the pulling direction of the pulling mandrel. Depending on the design, the expansion element can be rotationally symmetric, so that a uniform expansion of the expansion part can be achieved.

[0017] According to an alternative embodiment, the mechanical connection between the pulling mandrel and the catching part is formed by a rotational movement and / or a translational movement of the pulling mandrel. This allows the pulling mandrel to be pushed through the opening and to be hooked onto the catching part by a rotational movement or a lateral movement or a pivoting movement in such a way that the catching part presses against the inner side of the pole cap. Such a pulling mandrel can also be realized particularly easily technically and integrated into an automated process.

[0018] According to another embodiment, the pulling mandrel has a receiving part and / or a driving part. The receiving part is designed to laterally receive a part of the catching part. The driving part can advantageously protrude beyond the receiving part, so as to hook behind the catching part. The receiving part and the driving part can be eccentrically shaped with respect to the rotational axis of the pulling mandrel.

[0019] For example, the pulling mandrel can be pushed through the opening until the catching part and the pole cap are at the same height as the receiving part. An optional limiting element of the pulling mandrel can limit or control the insertion depth required for the pulling mandrel to pass through the opening. The tappet serves as the docking surface or contact surface of the catching part.

[0020] Depending on the design, the receiving part and the driving part of the pulling mandrel can form a screw shape or a thread shape. Thus, the pulling mandrel inserted into the opening can be rotated, so that due to the rotation along the rotational axis of the pulling mandrel, the effective position of the driving part moves in the direction of the inner side of the pole cap and thereby presses the catching part and the pole cap together. Alternatively, this can also be achieved outside the electrochemical cell by the thread of the pulling mandrel, which changes the axial position or the depth position of the pulling mandrel by rotating at least a part of the pulling mandrel.

[0021] The actuator can achieve rotational and / or translational movement of the drawing mandrel. Optionally, signals or measurement data from sensors and / or limit ends can be used to ensure a predetermined contact pressure of the catching part against the inner side of the pole cap. The control unit can achieve coordination between the sensor or limit end or end contact and the actuator.

[0022] Similarly, the control unit can also control the vacuum or overpressure to control the action of the drawing mandrel. In this case, additional sensors, such as pressure sensors or the like, can be used for the target control of the drawing mandrel.

[0023] In another advantageous design, before the battery cell or the electrochemical cell is installed, the drawing mandrel can be pushed through the opening of the catching part, so that the end of the tappet can be hooked behind the opening of the catching part or behind another part, or interact in a form-fitting or frictional manner. Then, the drawing mandrel can be used to move the catching part towards the pole cap, and thus the drawing mandrel can also be guided through the opening in the pole cap, so that after the battery cell has been assembled or after the battery housing has been closed, the catching part can be pulled against the inner side of the pole cap. The drawing mandrel can remain at least partially in the completed battery cell.

[0024] According to another embodiment, the drive part of the drawing mandrel is designed to mechanically engage with the catching part in the opening area. The drive part can be designed as, for example, a thickened part, an end T-piece, a head or a screw head, a spring, a side bulge and the like. The drive part can be used to prevent the drawing mandrel from freely sliding through the opening of the catching part.

[0025] According to another embodiment, the drawing mandrel is integrally formed with the catching part or connected to the catching part. In addition to the mechanical interaction between the drawing mandrel and the catching part, the drawing mandrel can be adhesively bonded, fusion-welded, brazed, crimped or clamped to the catching part to form a connection between the drawing mandrel and the catching part, which allows a force to be applied to the drawing mandrel to pull the catching part against the pole cap.

[0026] The drawing mandrel firmly connected to the catching part, for example by fusion welding or brazing, can be considered to be, for example, a drawing mandrel integrally designed with the catching part. During the production process, an integral component composed of the drawing mandrel and the catching part can also be formed, for example, by injection molding.

[0027] The catching part is advantageously moved to the inner side of the pole cap in such a way that the drawing mandrel is guided through the opening of the pole cap to the outside.

[0028] This allows the extraction mandrel to be partially retained in the battery cell. After connecting the pole cap to the capture piece, the part of the extraction mandrel protruding from the opening of the pole cap can be removed by milling, cutting, tearing, etc. According to the design, the connection between the capture piece and the pole cap can be established by a direct connection between the capture piece and the pole cap, and / or by an indirect conductive connection from the pole cap through the part of the extraction mandrel retained in the battery cell to the capture piece.

[0029] According to another embodiment, the capture piece is connected to the pole cap by an expansion part of the extraction mandrel in a form-fitting, material-bonding or friction-locking manner. For example, the capture piece can be connected to the pole cap by laser welding, tab welding, so-called e-filling, riveting, bending, pressing and similar methods. This enables the conductive connection between the pole cap and the capture piece to be achieved in various ways. In this case, the extraction mandrel can alternatively or additionally act as a rivet or a blind rivet. The drive part can be coupled to the capture piece, and the expansion part can be coupled to the pole cap, so that the capture piece can be connected to the pole cap in a technically particularly simple manner. In this case, the expansion part can advantageously be deformed, especially after a tensile force is applied to the protruding part of the extraction mandrel, by unfolding or widening.

[0030] The extraction mandrel integrally formed with the capture piece can be used in the same way. In this case, the expansion part can be located at a certain distance from the capture piece so that it can be deformed in or outside the opening of the pole cap.

[0031] In addition, holes can be welded through the pole cap and / or in the opening area of the pole cap, for example using laser welding.

[0032] If the extraction mandrel has a predetermined breaking point, the part of the extraction mandrel protruding from the battery cell can be removed particularly easily. Advantageously, after the expansion part expands, a tensile force and / or torque is applied to the extraction mandrel in such a way that at least a part of the extraction mandrel separates along the predetermined breaking point. This measure can remove the protruding extraction mandrel, and the extraction mandrel is partially permanently retained in the battery cell without additional tools or with a small number of tools.

[0033] Any remaining tear edges or residues of the extraction mandrel can be removed by welding, milling, grinding or similar methods.

[0034] The capture piece can be tilted or pressed, for example, by grooving in at least one transverse part or deforming the pole cap. In particular, this is achieved by the plastic deformation of the pole cap in at least some areas, and a mechanical connection between the pole cap and the capture piece is thereby formed. For this purpose, the pole cap can engage around the capture piece on the inside so that a conductive connection can also be formed on the inner walls of the pole cap and the capture piece.

[0035] According to a further embodiment, the pole cap has at least one connection opening. Preferably, wire bonding or plug welding or soldering connections are introduced through the at least one connection opening in order to form a material bond between the capture part and the pole cap. This measure ensures the formation of a material bond between the pole cap and the capture part. In addition, the formation of such a connection can be reliably checked as part of a quality management process.

[0036] If, after the capture part is connected to the pole cap, the draw mandrel is removed from the filling opening and the filling opening is used to fill the electrolyte, this process can be applied during the automated production process of a battery or a battery cell.

[0037] Alternatively, the tube part of the draw mandrel protruding from the pole cap leads into an opening designed as a filling opening for filling the electrolyte. This measure ensures that the draw mandrel is used as a filling pipe nozzle before the protruding part of the draw mandrel is cut off. This measure also enables the draw mandrel to be used for various possible tasks during the production of battery cells.

[0038] In particular, depending on the design, a plurality of draw mandrels used in parallel can lock a plurality of capture parts simultaneously and press them against the inner sides of a plurality of pole caps. The corresponding pole caps and capture parts can be simultaneously coupled in a conductive form through a plurality of parallel connections. This provides optimal scalability for the rapid mass production of battery cells. This measure can be implemented equally well in the case where the draw mandrel is permanently partially retained in the battery cell or in the case where the draw mandrel is temporarily inserted.

[0039] After the volume of the expansion part of the draw mandrel has decreased again, the temporarily inserted draw mandrel can be pulled out of the opening or the filling opening in order to fill the battery subsequently. This means that the filling opening can be used for multiple tasks, namely tightening the capture part and filling the battery. The temporarily inserted draw mandrel can basically use the expansion part to lock the capture part. In contrast, the draw mandrel permanently partially retained in the battery cell can use the expansion part to permanently lock the capture part, thereby realizing the function of a rivet.

[0040] In another embodiment, after filling the electrolyte, the filling opening is sealed in a fluid-tight manner. The steps of this process can be achieved in a technically simple manner, for example, by inserting a plug or a blind plug or by closing the filling opening in a material-bonding manner.

[0041] If a vacuum is created in advance in the internal volume of the battery, the battery can be filled particularly quickly.

[0042] According to another embodiment, within the region of the recess in the capture part, which is designed as a blind hole or an extruded profile groove, the draw mandrel expands and / or hooks at the end to be mechanically coupled to the capture part. This process enables the use of a cost-effective extruded profile tailored to the size of the pole cap. This means that the capture part can be manufactured in a particularly simple manner. Such an extruded profile can be used for both temporary and permanent draw mandrels. In a temporarily inserted draw mandrel, the expansion part can engage a part of the profile to enable the capture part to be moved from the outside. In a permanently installed draw mandrel, where part remains within the battery cell, the permanently formable expansion part or drive can interact with the profile part in a form-fitting or friction-fitting manner to move the capture part from the outside.

[0043] The use of blind holes and recesses or grooves in the extruded profile enables the capture part to be connected to the pole cap and at the same time enables the battery to be filled with the electrolyte solution.

[0044] If the capture part has at least one transverse connection part with an internal profile substantially corresponding to the inner side of the pole cap, the capture part can be electrically connected to the pole cap in a technically particularly simple manner. In this case, the capture part is connected to the pole cap by plastically deforming the pole cap in the region of the connection part. For example, grooving or extruding the pole cap in the region corresponding to the connection part on the outside can create an electrically conductive connection between the pole cap and the capture part.

[0045] If the capture part is connected to the pole cap in at least some regions by means of through-welding of the pole cap, the capture part can be electrically connected to the pole cap in a particularly simple technique. For example, the capture part led or pressed to the inner side of the pole cap by the draw mandrel can be connected in a material-integrated manner along the through-welding, which is completed by laser welding.

[0046] In an alternative or additional design, the capture part is electrically connected to the pole cap by welding at the joint between the expansion part and the opening of the pole cap, especially in the region of a predetermined breaking point. This enables the capture part to be indirectly connected to the pole cap through a part of the draw mandrel, for example between the tappet and the expansion part. In addition to the forces acting between the capture part, the drive, the expansion part and the pole cap, an optimal or additional fusion weld or brazed connection can improve the electrical contact resistance between the components.

[0047] Alternatively, or additionally, a welded connection can be formed between the capture part and the pole cap in the edge region of the opening or the filled opening. This process can be completed with or without a permanently used draw mandrel or a part of the draw mandrel.

[0048] The method can advantageously be carried out by means of one or more drawing mandrels. In this case, drawing mandrels that are only temporarily inserted from the outside or only permanently retained can be used, or a combination of temporarily inserted and permanently retained drawing mandrels can be used.

[0049] Several examples of the invention are explained in more detail in the following figures, in which:

[0050] Figure 1 is a cross-sectional schematic view of a battery cell with two battery stacks connected in parallel and pole caps arranged opposite each other,

[0051] Figure 2 is a detailed view B according to Figure 1 showing the method according to a first embodiment of the invention,

[0052] Figure 3 is a detailed view showing a capture member connected to a pole cap by means of penetration welding,

[0053] Figure 4 is a detailed view showing a capture member connected to a pole cap by means of plug welding,

[0054] Figure 5 is Figure 1 a top view of the pole cap of the battery cell shown,

[0055] Figure 6 is a detailed view of a battery cell with a capture member designed as an extruded profile,

[0056] Figure 7 is a detailed view of a battery cell showing the connection of a capture member to a pole cap by means of plastic deformation,

[0057] Figure 8 is a schematic detailed view showing the method according to a second embodiment of the invention, and

[0058] Figure 9 is a schematic detailed view for showing the method according to a third embodiment of the invention.

[0059] In the figures, the same reference numerals denote the same elements or structural parts. The dimensions and relative positions of the elements in the figures are not necessarily drawn to scale, and for clarity, some of these elements are enlarged or positioned. Additionally, the particular shape of the drawn elements is not intended to convey any information about the true shape of that particular element, and that particular shape is chosen only for ease of identification in the figures.

[0060] Figure 1It is a schematic cross-sectional view of an electrochemical cell or battery unit 100, which has two battery stacks 101, 102 connected in parallel, and the pole caps 10 are arranged opposite to each other. The pole caps of the battery unit 100 are arranged bilaterally or oppositely. The two battery stacks 101, 102 are arranged in the battery housing 110, and they are both conductively connected to the capture member 20 through connection lines 103 on the front side. For example, the battery housing 110 can have a rectangular or square cross-section and can be closed directly or indirectly through the pole caps 10 at the front end to accommodate the electrolyte solution.

[0061] At least one filling opening is provided for introducing the electrolyte solution into the housing capacity V of the battery unit, and the filling opening extends through at least one pole cap 10.

[0062] In the illustrated example, the capture member 20 is designed as a U-shaped capture member and has two legs 21, and both of the two legs are in electrical contact with the battery stacks 101, 102. The legs 21 of the capture member 20 are connected to each other by a cross member 22. The cross member 22 is conductively connected to the inner side 11 of the pole cap 10, so that the battery stacks 101, 102 are designed to be conductively connected to the pole cap 10. For example, these details are shown in Figure 2 are shown.

[0063] The first capture member 20 can be electrically connected to the first pole cap 10 in a technically simple manner. However, additional measures are required when subsequently connecting the second capture member 20 to the second pole cap 10, which will be described in more detail below. To avoid internal damage to the battery unit 100, direct force cannot be applied to the battery stacks 101, 102.

[0064] To achieve a reliable electrical connection between the capture member 20 and the pole cap 10, the initial gap 13 with the distance d between the inner side 11 of the pole cap 10 and the capture member 20 must be eliminated, and a so-called zero gap must be formed. Figure 2 Shown Figure 1 The detailed view B is shown to illustrate the method according to an embodiment of the present invention, and this figure also describes the method of forming a zero gap. For clear description, Figure 2 and the internal components such as the battery stacks 101, 102 and the connection lines 103 are not shown in the following drawings.

[0065] In one step of the method according to the present invention, a draw mandrel 30 that can expand at the end is pushed from the outside or from the outer side A through the opening 12 of the pole cap 10. In the illustrated embodiment, the opening 12 is designed as a filling opening for introducing the electrolyte solution into the housing capacity V. The draw mandrel 30 is also pushed through or into the opening 23 or groove 24 of the capture member 20 corresponding to the opening 12. For example, in Figure 5A capture member with such a groove 24 is shown. In the example shown, the draw mandrel 30 is temporarily retained within or on the components 10, 20 to enable zero clearance adjustment.

[0066] Then, within the region of the opening 23 or the groove 24 of the capture member 20, the draw mandrel 30 expands at its end to form a temporary mechanical connection between the draw mandrel 30 and the capture member 20.

[0067] In the next step, a force F directed outward from the opening 12 of the pole cap 10 is applied to the draw mandrel 30. This causes the capture member 20 to be pressed against the inner side 11 of the pole cap 10.

[0068] The capture member 20 pressed against the inner side 11 of the pole cap 10 eliminates the initial clearance 13 between the inner side 11 of the pole cap 10 and the capture member 20, thus optimally preparing for subsequent connection steps. Subsequently, in the connection step, the capture member 20 is connected to the pole cap 10 in an electrically conductive manner and preferably also in a mechanical manner.

[0069] The draw mandrel 30 has an outer tube portion 31 and an end expansion portion 32. In the illustrated embodiment, an expansion element 33 is disposed in the expansion portion 32. The expansion element 33 is designed to be conical, tapering in the direction of the force F, and can be introduced into the tube portion in such a way by mechanical operation or by vacuum that the cross-section of the end expansion portion increases. The arrow in the tube portion 31 schematically shows the movement of the expansion portion 33. The increase in this cross-section causes the expansion portion 32 to lock with the opening 23 of the capture member 20.

[0070] By at least partially form-fitting with the expansion portion 32, the locking device can be designed to restrain the movement of the capture member 20. In Figure 2 For example, the expansion portion 32 hooks behind the opening 23 of the capture member 20 to be able to pull the capture member 20 against the inner side 11 of the pole cap 10.

[0071] Due to the effect of the force F on the capture member 20, no force acts on the battery stacks 101, 102 simultaneously. Preferably, the separation between the battery stacks 101, 102 and the capture member 20 is achieved by a connecting wire 103. For this purpose, the connecting wire 103 can, for example, be designed to be slightly longer than the distance between the legs 21 of the capture member 20 and the end faces of the battery stacks 101, 102.

[0072] Figure 3 A detailed view is shown to illustrate the capture member 20 connected to the pole cap 10 by penetration welding 40. Figure 4 An alternative or additional option for a material-locking connection between the pole cap 10 and the capture member 20 is shown, Figure 4 A detailed view of the capture member 20 connected to the pole cap 10 by plug welding 41 is shown.

[0073] One or more welds 40 are produced, for example, by laser welding. After achieving a zero gap between the capture member 20 and the pole cap, an atypical welding device can be placed outside the pole cap 10 and can operate at least in some areas.

[0074] The weld 40 can, for example, enclose points, lines, and / or enclosed areas on the pole cap 10. Due to the relatively low material thickness of the pole cap 10, the crossbar 22 of the capture member 20 located behind the pole cap 10 is also melted and thus firmly connected to the pole cap 10.

[0075] Stud welding 41 can be used, for example, at the edge of the filling opening or in the area of the connection opening 12'. During this process, the edge area of the filling opening 12 is melted by the welding process to connect the pole cap 10 to the capture member 20. This still leaves a fluid passage for filling the electrolyte solution into the battery cell 100.

[0076] As Figure 5 shown, if more openings or connection openings 12' are used, these openings can be used to set welding points, for example, by laser welding, and thus completely close the connection openings 12'. Preferably, the corresponding connection openings 12' can be designed as blind holes. In this case, the groove or recess 24 of the capture member 20 or the crossbar 22 of the capture member 20 is positioned behind the opening 12' of the pole cap 10.

[0077] In addition, Figure 4 a detailed view of the capture member 20 connected to the pole cap 10 by stamping welding is shown, where the capture member 20 can be pulled to the inner side 11 of the pole cap 10 through the draw mandrel 30 at the recess or groove 24 instead of the corresponding opening 23. The material locking connection between the groove 24 and the pole cap 10 is particularly designed to be fluid-tight and does not require any additional closure 14 (see Figure 3 ). However, after the battery cell 100 is filled, the filling openings 12, 23 require a closure 14.

[0078] The closure 14 can be a reversible or irreversible closure that allows the housing volume V to be opened again or permanently closes the battery cell 100. For example, the closure 14 can be designed as a piston, threaded cap, fusion seal, or the like.

[0079] In an alternative or additional design, the groove 24 can have an internal thread such that, as an alternative to the welded connection, a bolt connection between the pole cap 10 and the capture member 20 can be formed by a bolt (not shown).

[0080] The groove 24 or recess can be formed on the cross member 22 of the catching member 20 by a material removal or forming process (such as stamping). At the same time, the legs 21 of the catching member 20 can also be formed by, for example, a stamping or forming step.

[0081] Figure 5 shows Figure 1 A top view of the pole cap 10 of the battery cell 100 shown. The pole cap 10 has a centrally arranged filling opening 12 and two openings 12', and the filling opening 12 and the opening 12' are arranged above the groove 24 of the catching member 20. The filling opening 12 is arranged above the corresponding opening 23 of the catching member 20 and forms a fluid passage leading to the housing volume V of the battery cell 100.

[0082] In the illustrated embodiment, for example, the opening 12' designed as a blind hole can be used to form a connection between the pole cap 10 and the catching member 20. To make the introduced weld or solder joint have the smallest possible protrusion, the pole cap 10 can have a groove or bevel (phasung) (not shown) in the region of the opening 12'.

[0083] Figure 6a and Figure 6b shows a detailed view of the battery cell 100 having a catching member 20 designed as an extruded profile. Figure 6a Shows the catching member 20, which is composed of an extruded profile having a V-shaped groove or recess 24. In contrast, the recess 24 in FIG. 6 is T-shaped.

[0084] The corresponding groove 24 extends along a spatial direction over the entire length of the catching member 20. The cross member 22 of the catching member 20 is interrupted by the groove 24 or has the groove 24. This groove 20 can be manufactured in a technically particularly simple manner by sawing a prefabricated extruded profile into a predetermined length.

[0085] Since the groove 24 extends over the entire length or width of the catching member 20, a blind hole is formed on the opening 12' of the pole cap 10, but an additional closure 14 is advantageous for preventing the leakage of the electrolyte solution. This design is schematically shown in Figure 6b in.

[0086] Figure 7a and Figure 7b Shows a detailed view of the battery cell 100 to illustrate the connection of the catching member 20 to the pole cap 10 achieved by plastic deformation 42. For the conductive connection between the pole cap 10 and the catching member 20, the catching member 20 has at least one transverse connection portion 25. In the illustrated embodiment, the connection portion 25 is arranged on two opposite sides or edges of the catching member 20 in the transition region between the corresponding legs 21 and the cross member 22, and the connection portion 25 is formed by, for example, the transverse extension of the cross member 22.

[0087] The transverse connecting portion 25 substantially corresponds to the transverse inner contour of the pole cap 10. Figure 7b The plastic deformation of the pole cap 10 within the region of the connecting portion 25 is shown. For example, this step can be accomplished by making an incision or pressing on the outer side of the pole cap 10 in the region of the connecting portion 25 or below the connecting portion 25, thereby creating an electrically conductive connection between the pole cap 10 and the capture member 20.

[0088] Figure 8a 、 Figure 8b and Figure 8c A detailed view is shown to illustrate the method according to the second embodiment of the present invention. In contrast Figure 2 to the shown drawing mandrel 30, this embodiment shows a drawing mandrel 30 which, by means of a rotational movement and / or a translational movement of the drawing mandrel 30, can form a mechanical connection to the capture member 20 such that the capture member 20 can be pulled against the inner side of the pole cap 10.

[0089] For simplicity, the shown drawing mandrel 30 is designed to rotate about a rotational axis R and has a receiving portion 34 and a drive member 35 of eccentric shape. The receiving portion 34 is designed as a groove and the tappet 35 limits the receiving portion 34 at the end. The tappet 35 serves as a contact surface for the capture member 20. After the drawing mandrel 30 is inserted into the opening 12, the receiving portion 34 is at the same axial height or depth as the capture member 20 and the pole cap 10. This step is shown in Figure 8a .

[0090] In a subsequent step, as Figure 8b described, the drawing mandrel 30 rotates about the rotational axis R by, for example, 90° to 180° such that the tappet 35 hooks behind the capture member 20. The capture member 20 and the pole cap 10 thereby enter into the receiving portion.

[0091] Subsequently, the drawing mandrel 30 is pulled out of the opening 12 with a pulling force F, achieving zero clearance and causing the capture member 20 to press against the pole cap 10, thereby ensuring a reliable weld, for example, between the two components 10, 20. This step is shown in Figure 8c . After the capture member 20 is welded to the pole cap 10, the drawing mandrel 30 can be rotated further about the rotational axis R or rotated back to align the drive member 35 with the opening 12 and the drawing mandrel 30 can be removed from the electrochemical cell 100.

[0092] Figure 9a 、 Figure 9b and Figure 9c A detailed view is shown to illustrate the method according to the third embodiment of the present invention. In contrast to the shown example, in Figure 9aIn the first step shown, a drawing mandrel 30 is used, and the drawing mandrel 30 can be partially permanently retained in the battery cell 100.

[0093] The drawing mandrel 30 has a drive member 35 formed at the end. The drive member 35 serves as the contact surface of the catching member 20 in the region of the opening 23 and is permanently retained in the battery cell 100. Depending on its design, the drive member 35 can lock the catching member 20 in one or more directions or restrict its movement. In the example shown, for instance, there is a restriction on the direction of the force F that acts on the drawing mandrel 30 to eliminate the initial clearance 13.

[0094] The drawing mandrel 30 can, for example, be arranged on the catching member 20 before the pole cap 10 is installed. The pole cap 10 is set on the catching member 20 in such a way that the pre-inserted drawing mandrel 30 can be guided through the opening 12.

[0095] In an alternative embodiment, the drawing mandrel 30 can be an integral part of the catching member 20. In this case, the drawing mandrel 30 and the catching member 20 can be integrally formed, or can be formed by a material-locking connection or a form-locking connection of the drawing mandrel 30 to the catching member 20. Thus, the drawing mandrel 30 can be connected to the catching member 20 by welding, bending, gluing, crimping or the like. This particularly ensures the best electrical conductivity between the drawing mandrel 30 and the catching member 20.

[0096] The drawing mandrel 30 also has an outer tube portion 31 and an expansion portion 32. In the example shown, the expansion portion 32 is arranged downstream of the tappet 35 in the direction of the outer side A.

[0097] The expansion portion 32 is located at a certain distance from the catching member 20, whereby the expansion portion 32 can be deformed inside or outside the opening 12 of the pole cap 10. In addition, the drawing mandrel 30 has a predetermined breaking point 36, which is located downstream of the expansion portion 32.

[0098] Figure 9b Steps in this process are shown, in which a force F is applied to the drawing mandrel 30. This eliminates the initial clearance 13 between the catching member 20 and the inner side 11 of the pole cap 10. The tensile force between the components 10, 20, 30 is maintained, and the expansion portion 32 expands. This can be achieved, for example, by inserting an expansion element (not shown) in the form of a bolt through the tube portion 31, which results in an increase in the cross-section due to the plastic deformation of the expansion portion 32. The force N required for the plastic deformation is schematically shown, and this force is achieved relative to the tensile force F acting on the drawing mandrel 30. Due to the deformation of the expansion portion 32, the drawing mandrel 30 performs the function of a rivet and connects the catching member 20 to the pole cap 10.

[0099] According to the design, the tube part 31 can lead into the integrated opening 12" in the draw mandrel 30 within the region of the expansion part 32, and the opening 12" can serve as a filling opening for the electrolyte.

[0100] Subsequently, the protruding part 31' of the draw mandrel 30 can be removed along a predetermined breaking point 36. By tilting and / or twisting the part 31' of the draw mandrel 30 relative to the pole cap 10 or the plastically deformed expansion part 32, overuse of the predetermined breaking point 36 can be caused. This step is shown in Figure 9c Thus, a permanent mechanical connection is formed between the draw mandrel 30, the catching part 20, and the pole cap 10.

[0101] The part 31" of the draw mandrel 30 that is permanently retained within the battery cell 100 can be machined within the region of the plastically deformed expansion part 32 to prepare the outer surface of the pole cap 10 as required.

[0102] The retained part 31" of the draw mandrel 30 not only forms a mechanical connection but also forms an electrical connection between the catching part 20 and the pole cap 10. Optionally, the deformed expansion part 32 of the retained part 31" and the transition region to the pole cap 10 can be machined by milling, drilling, grinding, welding, and the like. For example, the part 31" can be achieved by sliding friction, such as a thermal friction drilling process.

Claims

1. A method for connecting a capture member (20) to the inner side (11) of a pole cap (10) of an electrochemical cell (100), wherein, Push the drawing mandrel (30) through the openings (12, 12') of the pole cap (10) and / or through the opening (23) of the capture member (20), wherein the drawing mandrel (30) is arranged to form a mechanical connection between the drawing mandrel (30) and the capture member (20) at least temporarily at a part (31”), or the drawing mandrel (30) is mechanically connected to the capture member (20), wherein a force (F) acting outward from the opening (12) of the pole cap (10) acts on the drawing mandrel (30) and the capture member (20) presses against the inner side (11) of the pole cap (10), wherein the capture member (20) pressing against the inner side (11) of the pole cap (10) is connected to the pole cap (10), in particular in a conductive manner.

2. The method according to claim 1, wherein the drawing mandrel (30) moves in an outward (A) direction through the opening (23) of the capture member (20), wherein, In the region of the opening (23), the drawing mandrel (23) is mechanically locked, in particular positively locked, with the capture member (20) at the end; or, wherein, in the region of the opening (23) of the capture member (20), the drawing mandrel (30) forms a temporary or permanent mechanical connection with the capture member (20) mechanically or by overpressure, in particular pneumatically or hydraulically, or by vacuum expansion, at the end.

3. The method according to claim 2, wherein The drawing mandrel (30) has an outer tube part (31), and the outer tube part (31) has an expansion part (32) at the end, wherein the expansion part (32) expands at least in some regions by applying overpressure to the tube part (31) or by pressing in a bolt or an expansion element (33).

4. The method according to claim 3, wherein the expansion part (32) includes an expansion element (33), and the expansion element (33) is mechanically or pulled or pressed into the outer tube part (31) by vacuum so that the expansion part (32) expands at least in some regions.

5. The method according to claim 1, wherein the mechanical connection between the drawing mandrel (30) and the capture member (20) is formed by a rotational movement and / or a translational movement of the drawing mandrel (30).

6. The method according to claim 5, wherein the drawing mandrel (30) has a receiving part (34) and / or a driving part (35).

7. The method according to claim 6, wherein the driving part (35) of the drawing mandrel (30) is arranged to mechanically hook with the capture member (20) in the region of the opening (23).

8. The method according to any one of claims 1 to 7, wherein the drawing mandrel (30) is integral with or connected to the capture member (20), wherein, The capture member (20) moves towards the inner side (11) of the pole cap (10) so that the drawing mandrel (30) passes through the opening (12) of the pole cap (10) to the outer side (A).

9. The method according to any one of claims 1 to 8, wherein The capture member (20) is connected to the pole cap (10) in a form-fitting or material-fitting or friction-fitting manner by the expansion part (32) of the drawing mandrel (30).

10. The method according to any one of claims 1 to 9, wherein, The drawing mandrel (30) has a predefined breaking point (36), and after the expansion part (32) is expanded, a tensile force and / or a torque is applied to the drawing mandrel (30) in such a way that at least one part (31') of the drawing mandrel (30) separates along the predefined breaking point (36).

11. The method according to any one of claims 1 to 10, wherein The pole cap (10) has at least one connecting opening (12'), and a wire bonding, hole welding or soldering connection is introduced through the at least one connecting opening (12') to form a material - fitting connection between the catching part (20) and the pole cap (10).

12. The method according to any one of claims 1 to 8, wherein After connecting the catching part (20) to the pole cap (10), the drawing mandrel (30) is removed from an opening (12) designed as a filling opening, and the opening (12) is used for filling an electrolyte, or alternatively, the tube part (31) of the drawing mandrel (30) leads into an opening (12”) designed as a filling opening, and the opening (12”) is used for filling an electrolyte.

13. The method according to any one of claims 1 to 9, wherein in the region of a groove (24) of the catching part (20) designed as a blind hole or an extruded profile, the drawing mandrel (30) expands and / or hooks at the end to mechanically couple the catching part (20).

14. The method according to any one of claims 1 to 11, wherein The catching part (20) has at least one transverse connecting part (25) that substantially corresponds to the inner contour of the pole cap (10), particularly in the region of the inner side (11), and the catching part (20) is connected to the pole cap (10) by plastic deformation of the pole cap (10) in the region of the connecting part (25).

15. The method according to any one of claims 1 to 12, wherein The catching part (20) is connected to the pole cap (10) in at least some regions by welding (40) through the pole cap (10) and / or by welding at the joint between the expansion part (32) and the opening (12) of the pole cap (10), particularly in the region of the predefined breaking point (36).

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