Method for connecting an arrester to a pole cap of a battery cell

Abstract

The invention relates to a method for connecting an arrester (20) to an inner side (11) of a pole cap (10) of an electrochemical cell (100), wherein a mandrel (30) is pushed through an opening (12, 12') of the pole cap (10) and / or through an opening (23) or recess (24) of the arrester (20), wherein the mandrel (30) is configured to form a mechanical connection between the mandrel (30) and the arrester (20) or is mechanically connected to the arrester (20) at least temporarily at a section (31''), wherein a force (F) directed from the opening (12) of the pole cap (10) onto the mandrel (30) is set and the arrester (20) is pressed against the inner side (11) of the pole cap (10), wherein the arrester (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] Method for connecting an arrester to a terminal cap of a battery cell

[0002] The invention relates to a method for connecting an arrester to an inner side of a pole cap of an electrochemical cell.

[0003] In the manufacture of electrochemical storage devices, such as lithium-ion batteries, several alternating layers of anodes, cathodes, and separators are typically arranged in cell stacks. The respective anodes and cathodes are each electrically connected by a conductor. When using two cell stacks, for example, U-shaped conductors are used, with the two ends facing the two cell stacks and the front side facing the inside of a pole cap. The conductor acts as an electrical interface between the cell stacks and the pole caps.

[0004] Due to the bilateral or opposing arrangement of pole caps, the first pole cap can be welded or soldered to the cell stack's arrester without any technical challenges. The second pole cap can no longer be connected directly to the arrester. This requires longer connecting cables between the second arrester and the cell stack, which requires additional housing volume for the longer connecting cables required for installation.

[0005] The present invention therefore aims to provide a method for connecting a down conductor, in particular a second down conductor to be connected, in which the volume of the cell housing can be minimized. This object is achieved by the features specified in claim 1. Further advantageous embodiments of the invention are part of the dependent claims.

[0006] According to one aspect of the invention, a method for connecting a conductor to an inner surface of a pole cap of an electrochemical cell is provided.

[0007] In one step, a tension mandrel is pushed through an opening, such as a filling opening, in the pole cap and / or through an opening or recess in the arrester. The opening in the arrester can be designed to correspond to the opening in the pole cap. Depending on the design of the tension mandrel, an opening in the arrester may not be necessary if the tension mandrel is mechanically or integrally connected to the arrester.

[0008] The tension dome can be spread at one end on a section of the arrester or be mechanically connected to the arrester to form at least a temporary mechanical connection between the tension dome and the arrester. Depending on the design, the tension dome can be permanently connected to the arrester at the end or can be connectable.

[0009] In a further step, a force is applied to the tension dome, directed outwards from the filling opening of the pole cap. This presses the arrester against the inside of the pole cap. By pressing or pulling the arrester against the inside of the pole cap, an initial gap between the inside of the pole cap and the arrester can be eliminated, thereby implementing optimal preparation for a subsequent joining step. Subsequently, in the joining step, the arrester is connected to the pole cap, in particular in an electrically conductive manner. This method can be used to set a so-called zero gap between the pole cap and the arrester in order to implement a process-reliable connection between the pole cap and the arrester. In particular, this method allows the arrester to be pulled or pressed against the pole cap from the outside without exerting a damaging force on the at least one cell stack connected to the arrester.

[0010] Furthermore, the process can minimize the need for additional cell volume, as no additional length is required for the connection between the arrester and the cell stack.

[0011] According to one embodiment, the tension dome is moved through an opening in the arrester towards an outer side. The tension dome is mechanically, in particular positively, hooked to the arrester at its end in the region of the opening. Alternatively, the tension dome is inserted through the openings in the pole cap and the arrester and spread at its end in the region of the arrester opening mechanically or by overpressure, in particular pneumatically or hydraulically, or by negative pressure, in order to form a temporary or permanent mechanical connection between the tension dome and the arrester. This allows the tension dome to be enlarged in many different ways at its end in order to lock the arrester and thus fix it immovably in relation to the tension dome at least in one direction. Depending on the design, the tension dome can hook behind the arrester or form a temporary, fixed connection with the arrester in order to be able to move the arrester against the pole cap.Thus, the tension mandrel can be enlarged or expanded within an opening or recess of the arrester, or behind or below the opening, to allow the arrester to move in at least one direction. The tension mandrel can be spread at the end in such a way that this end section deforms and acts as a rivet, forming a mechanical connection between the arrester and the pole cap.

[0012] In particular, the tension dome can be designed to pull the arrester and thus press or move it against an inner side of the pole cap.

[0013] According to a further embodiment, the tension mandrel has an outer tubular section which has an expansion section at its end. The expansion section is preferably enlarged at least in some regions by applying excess pressure to the tubular section or by pressing in a bolt. This makes it technically easy to expand the end of the tension mandrel. The expansion section can be designed to be elastic at least in some regions in order to increase or decrease the dimensions of the tension mandrel transversely to the tensile direction of the arrester. The tension mandrel can function as a tool with which the expansion section is temporarily expanded. In an alternative or additional embodiment, the tension mandrel can serve as a connecting means with which the expansion section can be permanently expanded.

[0014] The tension dome can be designed in a particularly simple technical manner if the expansion section has an expansion element and the expansion element is pulled or pressed into the outer tube section mechanically or by negative pressure in order to enlarge the expansion section at least in part. Accordingly, the expansion element can be spaced apart from the outer tube section by mechanical action or by positive pressure in order to reduce the expansion section again. Depending on the design, a return spring can be provided which can automatically space the expansion element from the outer tube section along the pulling direction of the tension dome in order to reduce the expanding section. The expanding section can be enlarged by the expansion element along at least one spatial direction transverse to the pulling direction of the tension dome. Depending on the design, the expansion element can be designed to be rotationally symmetrical, whereby a uniform enlargement of the expanding section can be implemented.

[0015] According to an alternative embodiment, the mechanical connection between the tension mandrel and the arrester is formed by a rotational movement and / or a translational movement of the tension mandrel. This allows the tension mandrel to be pushed through the opening and, by means of a rotational movement, lateral movement, or pivoting movement, to hook behind the arrester so that it can be pressed against the inside of the pole cap. Such a tension mandrel can also be implemented with particular technical simplicity and integrated into an automated process.

[0016] According to a further embodiment, the tension dome has a receiving section and / or a driver. The receiving section is designed to laterally accommodate a portion of the arrester. Advantageously, the driver can protrude beyond the receiving section, thereby creating a rear hook for the arrester. The receiving section and the driver can be shaped eccentrically with respect to a rotational axis of the tension dome.

[0017] For example, the tension dome can be pushed through the opening until the arrester and the pole cap are at the same height in the receiving section. An optional limiting element of the tension dome can limit or regulate the required immersion depth of the tension dome through the opening. The driver acts as a counter surface or support surface for the arrester. Depending on the design, the receiving section and the driver of the tension dome can form a screw shape or thread shape. This means that a tension dome inserted into the opening can be rotated, whereby the rotation along the rotation axis of the tension dome causes the effective position of the driver to move towards the inside of the pole cap, thus pressing the arrester and the pole cap together. Alternatively, this can also be achieved by a thread on the tension mandrel outside the electrochemical cell, which thread determines the axial position or the axial direction by rotating at least part of the tension dome.Depth position of the tension dome changed.

[0018] An actuator can implement the rotational and / or translational movement of the tension dome. Optionally, signals or measurement data from sensors and / or end stops can be used to press the arrester against the inside of the pole cap in a defined manner. A control unit can coordinate the sensors, end stops, or end contacts with the actuators.

[0019] Similarly, the control unit can also control the application of negative or positive pressure to the tension dome. Additional sensors, such as pressure sensors and the like, can be used for targeted control of the tension dome.

[0020] In a further advantageous embodiment, the tension dome can be pushed through the opening in the arrester before the battery cell or electrochemical cell is installed, so that the driver can hook behind the opening or another section of the arrester at the end, or interact with it in a form-fitting or frictional manner. The arrester can then be brought closer to the pole cap with the tension dome, whereby the tension dome can also be guided through the opening in the pole cap in order to be able to pull the arrester against the pole cap on the inside after the battery cell has been installed or after the cell housing has been closed. The tension dome can remain in the finished battery cell, at least in part.

[0021] According to a further embodiment, the driver of the tension dome is designed to mechanically interlock with the arrester in the area of ​​the opening. The driver can be designed, for example, as a thickened section, a T-piece at the end, a head or screw head, a spring, a lateral bulge, and the like. The driver can prevent the tension dome from freely slipping through the opening of the arrester.

[0022] According to a further embodiment, the tension dome is designed integrally with the arrester or is connected to the arrester. In addition to mechanical interaction with the arrester, the tension dome can also be glued, welded, soldered, crimped, or clamped to the arrester to form a connection between the tension dome and the arrester, which allows a force to be applied to the tension dome to pull the arrester against the pole cap.

[0023] A tension dome that is firmly connected to the arrester, for example, by welding or soldering, can be considered an integral tension dome. An integral assembly consisting of the tension dome and the arrester can also be formed during production, for example, by injection molding.

[0024] Advantageously, the arrester is moved to the inside of the pole cap in such a way that the tension dome is guided through the opening in the pole cap to the outside. This allows the tension dome to remain partially in the battery cell. After the pole cap has been connected to the arrester, the section of the tension dome protruding from the opening in the pole cap can be removed by milling, cutting, tearing off, or the like. Depending on the design, a connection between the arrester and the pole cap can be made via a direct connection between the arrester and the pole cap and / or via an indirect electrically conductive connection that runs from the pole cap via the section of the tension dome remaining in the battery cell and to the arrester.

[0025] According to a further embodiment, the arrester is connected to the pole cap by means of the expanded expansion section of the tension dome in a form-fitting, material-fitting, or friction-fitting manner. For example, the arrester can be connected to the pole cap by laser welding, tab welding, so-called e-filling, riveting, canting, pressing, and the like. This allows for a versatile electrically conductive connection between the pole cap and the arrester. The tension dome can alternatively or additionally function as a rivet or blind rivet. The driver can couple the arrester and the expansion section to the pole cap, making it particularly easy to connect the arrester to the pole cap. The expansion section can advantageously be deformed, in particular fanned out or widened, after the tensile force is applied to the projecting section of the tension dome.

[0026] A tension dome designed integrally with the arrester can be used analogously. The expansion section can be positioned at a distance from the arrester, allowing it to be deformed inside or outside the opening of the pole cap. Furthermore, plug welding, for example, in the form of laser welding, can be implemented through the pole cap and / or in the area of ​​the opening.

[0027] A section of the tension mandrel protruding from the battery cell can be removed particularly easily if the tension mandrel has a predetermined breaking point. Advantageously, after the expansion section has been expanded, the tension mandrel is subjected to a tensile force and / or torque such that at least a section of the tension mandrel is severed along the predetermined breaking point. This measure enables the removal of a protruding tension mandrel, which remains permanently in the battery cell in sections, without the need for additional tools or with minimal tooling effort.

[0028] Any remaining tear-off edge or stump of the tension dome can be removed by welding, milling, grinding and the like.

[0029] The tilting or compression of the arrester can be achieved, for example, by notching or deforming the pole cap in at least one lateral section. This is achieved, in particular, by at least partially plastically deforming the pole cap and results in a mechanical connection between the pole cap and the arrester. For this purpose, the pole cap can engage around the inside of the arrester to form an electrical contact even on the side walls of the pole cap and the arrester.

[0030] According to a further embodiment, the pole cap has at least one connection opening. Preferably, a line weld, a plug weld, or a soldered connection is introduced through the at least one connection opening to form a bonded connection between the arrester and the pole cap. This measure ensures the formation of a bonded connection between the pole cap and the arrester. Furthermore, the formation of such a connection can be reliably verified as part of quality management.

[0031] The process can be used in automated cell or battery cell production if, after connecting the arrester to the pole cap, the tension dome is removed from the filling opening and the filling opening is used to fill an electrolyte.

[0032] Alternatively, the tubular section of the tension dome that protrudes from the pole cap opens into an opening designed as a filling port, which is used for filling the electrolyte. This feature allows the tension dome to be used as a filler neck before the protruding section of the tension dome is removed. This feature allows the tension dome to be used simultaneously for a variety of possible tasks within battery cell production.

[0033] In particular, depending on the design, several tension domes used in parallel can simultaneously lock several arresters and press them against the inside of several pole caps. The respective pole caps and arresters can then be electrically coupled simultaneously using several parallel connections. This results in optimal scalability of the process for rapid series production of battery cells. This measure can be implemented equally well with a tension mandrel that remains permanently in the battery cell in sections or with a temporarily inserted tension dome. After the spreading sections of the tension domes have been reduced in size again, in the case of temporarily inserted tension domes, these can be pulled out of the openings or filling openings to enable subsequent filling of the cells. This measure allows the filling opening to be used for several tasks: tightening the arrester and filling the cell.The temporarily inserted tension domes can essentially use the expansion section to lock the arrester in place. The tension domes that remain permanently in the battery cell for a limited time can, however, use the expansion section to permanently lock the pole cap, thus implementing the function of a rivet.

[0034] In another embodiment, the filling opening is sealed fluid-tight after filling with the electrolyte. This step of the process can be easily implemented, for example, by inserting a plug or blind plug or by sealing the filling opening with a material bond.

[0035] The cells can be filled particularly quickly if a vacuum or negative pressure is created in the interior volume of the cell beforehand.

[0036] According to a further embodiment, the tension dome is spread and / or hooked at the end in the area of ​​a recess in the arrester designed as a blind hole or as an extruded profile in order to mechanically couple it. This measure allows the use of cost-effective extruded profiles tailored to the dimensions of the pole caps. The manufacture of the arresters can thus be technically particularly simple. Such extruded profiles can be used for both temporarily and permanently installed tension domes. In the case of temporarily installed tension domes, spreading sections can engage into a section of the profile to enable the arrester to be moved from the outside.In the case of a permanently inserted tension dome, which remains partially in the battery cell, a permanently deformable expansion section or a driver can interact with the section of the profile in a form-fitting, material-fitting or friction-fitting manner in order to be able to move the arrester from the outside.

[0037] The use of blind holes and recesses or grooves in extruded profiles can enable the arrester to be pulled towards the pole cap and the cell to be filled with an electrolyte solution at the same time.

[0038] The arrester can be electrically connected to the pole cap particularly easily if the arrester has at least one lateral connection section that essentially corresponds to an inner contour of the pole cap in the inner region. The arrester is connected to the pole cap by plastically deforming the pole cap in the region of the connection section. For example, notching or pressing the pole cap on the outside in the region of the connection section can create an electrically conductive connection between the pole cap and the arrester.

[0039] The arrester can be electrically connected to the pole cap particularly easily if the arrester is connected to the pole cap at least partially by means of a penetration weld through the pole cap. For example, an arrester that is pulled or pressed onto the inside of the pole cap by the tension dome can be firmly bonded along the penetration weld using laser welding.

[0040] In an alternative or additional embodiment, the arrester is electrically connected to the pole cap by welding a joint between the expansion section and the opening of the pole cap, particularly in the area of ​​a predetermined breaking point. This allows the arrester to be indirectly connected to the pole cap via a section of the tension dome, for example, between the driver and the expansion section. In addition to the forces acting between the arrester, the driver, the expansion section, and the pole cap, optimal or additional welding or soldering can improve the electrical contact resistance between the components.

[0041] Alternatively or additionally, a welded edge connection can be formed between the arrester and the pole cap near the edges of the openings or filling openings. This can be achieved with or without a permanently used tension dome or section of the tension dome.

[0042] The method can advantageously be implemented with one or more tension mandrels. This can be a tension mandrel that is inserted temporarily from the outside, a tension mandrel that remains permanently, or a combination of temporary and permanent tension mandrels.

[0043] Several embodiments of the invention are explained in more detail below with reference to the drawings. They show:

[0044] Fig. 1 is a schematic sectional view of a battery cell with two cell stacks connected in parallel and oppositely arranged pole caps,

[0045] Fig. 2 is a detailed view B from Fig. 1 to illustrate a method according to a first embodiment of the invention, Fig. 3 is a detailed view to illustrate an arrester connected to a pole cap by means of a penetration weld,

[0046] Fig. 4 is a detailed view illustrating an arrester connected to a pole cap by means of a plug weld,

[0047] Fig. 5 is a plan view of a pole cap of the battery cell shown in Fig. 1,

[0048] Fig. 6 Detailed views of a battery cell with an arrester designed as an extruded profile,

[0049] Fig. 7 Detailed views of a battery cell to illustrate a connection of a conductor with a pole cap by plastic deformation,

[0050] Fig. 8 schematic detailed views to illustrate a method according to a second embodiment of the invention, and

[0051] Fig. 9 schematic detailed views to illustrate a method according to a third embodiment of the invention.

[0052] In the illustrations, identical reference numerals identify the same elements or structural components. The sizes and relative positions of the elements in the illustrations are not necessarily drawn to scale, and some of these elements are enlarged and positioned for clarity. Furthermore, the specific shapes of the elements shown are not intended to convey information about the actual shape of the individual elements, but were selected merely for ease of identification in the illustrations.

[0053] Fig. 1 shows a schematic sectional view of an electrochemical cell or battery cell 100 with two cell stacks 101, 102 connected in parallel and oppositely arranged pole caps 10. The battery cell 100 has a bilateral or opposite arrangement of pole caps 10. Two cell stacks 101, 102 are arranged in the cell housing 110, each of which is electrically connected at its end face to a conductor 20 via connecting lines 103. The cell housing 110 can, for example, have a rectangular or square cross-section and can be closed at its end face directly or indirectly by the pole caps 10 in order to accommodate an electrolyte solution.

[0054] For introducing the electrolyte solution into a housing volume V of the battery cell 100, at least one filling opening 12 is provided, which extends through at least one pole cap 10.

[0055] In the illustrated embodiment, the arresters 20 are designed as U-shaped arresters and have two legs 21, each of which electrically contacts a cell stack 101, 102. The legs 21 of the arresters 20 are connected to one another by a crosspiece 22. The crosspiece 22 is electrically conductively connected to an inner side 11 of the pole cap 10, so that the cell stacks 101, 102 are electrically conductively connected to the pole caps 10. These details are illustrated, for example, in Fig. 2.

[0056] A first arrester 20 can be easily electrically connected to a first pole cap 10. However, a subsequent connection of a second arrester 20 to a second pole cap 10 requires additional measures, which are described in more detail below. To avoid internal damage to the battery cell 100, no direct force may be applied to the cell stacks 101, 102.

[0057] For a reliable electrical connection between the arrester 20 and the pole cap 10, an initial gap 13 with a distance d between the inner side 11 of the pole cap 10 and the arrester 20 must be eliminated, and a so-called zero gap must be formed. Figure 2 shows a detailed view B from Figure 1 to illustrate a method according to an embodiment of the invention, which also describes one possibility for forming the zero gap. For the sake of clarity, the internal components, such as the cell stacks 101, 102 and the connecting lines 103, are not shown in Figure 2 and the following figures.

[0058] In one step of the method according to the invention, a tensile dome 30, which can be spread apart at its end, is pushed from the outside or from an outer side A through an opening 12 of the pole cap 10. In the illustrated embodiment, the opening 12 is designed as a filling opening for introducing an electrolyte solution into the housing volume V. The tensile dome 30 is also pushed through or into an opening 23 or recess 24 of the arrester 20 corresponding to the opening 12. An arrester 20 with such a recess 24 is illustrated, for example, in Fig. 5. In the illustrated embodiment, the tensile dome 30 remains temporarily in or on the components 10, 20 in order to be able to adjust the zero gap.

[0059] The tension dome 30 is then spread at the end in the area of ​​the opening 23 or recess 24 of the arrester 20 to form a temporary mechanical connection between the tension dome 30 and the arrester 20. In a further step, a force F is applied to the tension dome 30, directed out of the opening 12 of the pole cap 10. This presses the arrester 20 against the inner side 11 of the pole cap 10.

[0060] By pressing the arrester 20 against the inner side 11 of the pole cap 10, the initial gap 13 between the inner side 11 of the pole cap 10 and the arrester 20 is eliminated, thus ensuring optimal preparation for a subsequent joining step. Subsequently, in the joining step, the arrester 20 is electrically and preferably also mechanically connected to the pole cap 10.

[0061] The tension dome 30 has an outer tube section 31 and an end-side expansion section 32. In the illustrated embodiment, an expansion element 33 is arranged in the expansion section 32. The expansion element 33 is conically tapered in the direction of the force F and can be drawn into the tube section by mechanical actuation or by a vacuum such that the end-side expansion section increases in cross-section. The arrow in the tube section 31 schematically illustrates the movement of the expansion element 33. This cross-sectional increase results in the expansion section 32 being locked to the opening 23 of the arrester 20.

[0062] The locking mechanism can be designed to restrict the mobility of the arrester 20 by at least partially positively locking the expansion section 32. In Fig. 2, for example, the expansion section 32 is hooked behind the opening 23 of the arrester 20 in order to be able to pull the arrester 20 against the inner side 11 of the pole cap 10. By applying the force F to the arrester 20, no force is exerted on the cell stacks 101, 102 at the same time. Preferably, the connecting lines 103 provide decoupling between the cell stacks 101, 102 and the arrester 20. For this purpose, the connecting lines 103 can, for example, be designed to be slightly longer than a distance between the legs 21 of the arrester 20 and the end faces of the cell stacks 101, 102.

[0063] Fig. 3 shows a detailed view illustrating an arrester 20 connected to a pole cap 10 by means of a penetration weld 40. An alternative or additional possibility of a materially bonded connection between the pole cap 10 and the arrester 20 is shown in Fig. 4, which is a detailed view illustrating an arrester 20 connected to a pole cap 10 by means of a plug weld 41.

[0064] One or more penetration welds 40 are created, for example, by laser welding. After adjusting the zero gap between the arrester 20 and the pole cap, a welding device (not shown) can be attached to the outside of the front side of the pole cap 10 and activated at least in part.

[0065] A penetration weld 40 can, for example, be point-shaped, linear, and / or enclose a closed area on the pole cap 10. Due to the relatively thin material thickness of the pole cap 10, the crosspiece 22 of the arrester 20 arranged behind the pole cap 10 is also melted and thus integrally connected to the pole cap 10. A plug weld 41 can, for example, be made at the edge of the filling opening 12 or in the region of a connecting opening 12' (see Fig. 5). In this case, an edge region of the filling opening 12 is melted by a welding process in order to connect the pole cap 10 to the arrester 20. This leaves a fluid channel for filling the battery cell 100 with the electrolyte solution.

[0066] If, as indicated in Fig. 5, additional openings or connecting openings 12' are used, these can be used to create a weld spot, for example by laser welding, and thus completely close the connecting opening 12'. A corresponding connecting opening 12' can preferably be designed as a blind hole. A recess or depression 24 of the arrester 20 or the transverse web 22 of the arrester 20 is positioned behind the opening 12' in the pole cap 10.

[0067] Furthermore, Fig. 4 shows a detailed view illustrating a conductor 20 connected to a pole cap 10 by means of a plug weld. In this case, the conductor 20 can be pulled through the tension dome 30 to the inner side 11 of the pole cap 10 not at a corresponding opening 23, but at a recess or cutout 24. A materially bonded connection between the recess 24 and the pole cap 10 is designed to be particularly fluid-tight and does not require any additional closures 14 (see Fig. 3). The filling opening 12, 23, however, requires a closure 14 after filling the battery cell 100.

[0068] The closure 14 can be a reversible or irreversible closure, which allows the housing volume V to be reopened or permanently seals the battery cell 100. For example, the closure 14 can be designed as a plug, a screw closure, a fusible closure, and the like. In an alternative or additional embodiment, the recess 24 can have an internal thread, so that, as an alternative to a welded connection, a screw connection can be formed between the pole cap 10 and the conductor 20 using a screw (not shown).

[0069] The recess 24 or cutout can be created by material removal or by a forming process, such as punching, in the crosspiece 22 of the arrester 20. At the same time, the legs 21 of the arrester 20 can also be formed, for example, with a punching or forming step.

[0070] Fig. 5 shows a plan view of a pole cap 10 of the battery cell 100 shown in Fig. 1. The pole cap 10 has a centrally arranged filling opening 12 and two openings 12', which are arranged above recesses 24 of the discharge conductor 20. The filling opening 12 is arranged above a corresponding opening 23 of the discharge conductor 20 and forms a fluid channel to the housing volume V of the battery cell 100.

[0071] In the illustrated embodiment, for example, the openings 12' designed as blind holes can function to form a connection between the pole cap 10 and the conductor 20. To ensure that the weld seam or weld point has the smallest possible projection, the pole cap 10 can have a recess or phasing (not shown) in the region of the openings 12'.

[0072] Figures 6a and 6b show detailed views of a battery cell 100 with a conductor 20 configured as an extruded profile. Figure 6a shows a conductor 20 consisting of an extruded profile with a V-shaped recess or depression 24. In comparison, the depression 24 in Figure 6b is T-shaped.

[0073] The corresponding recesses 24 extend over the entire length of the arrester 20 along one spatial direction. The crossbar 22 of the arrester 20 is interrupted by the recess 24 or has the recess 24. Such arresters 20 can be manufactured particularly easily from a technical perspective, with prefabricated extruded profiles being sawn to a predefined length.

[0074] Because the recess 24 extends across the entire length or width of the arrester 20, a blind hole is formed with the opening 12' of the pole cap 10, an additional closure 14 is advantageous to prevent leakage of the electrolyte solution. This configuration is schematically illustrated in Fig. 6b.

[0075] Fig. 7a and Fig. 7b show detailed views of a battery cell 100 to illustrate a connection of a conductor 20 to a pole cap 10 by plastic deformation 42. For such an electrically conductive connection between the pole cap 10 and the conductor 20, the conductor 20 has at least one lateral connecting section 25. In the illustrated embodiment, a connecting section 25 is arranged on two opposite sides or edges of the conductor 20 in a transition region between a respective leg 21 and the transverse web 22, which connecting section is designed, for example, as a lateral extension of the transverse web 22.

[0076] The lateral connecting sections 25 essentially correspond to a lateral inner contour of the pole cap 10. Fig. 7b illustrates the plastic deformation of the pole cap 10 in the region of the connecting sections 25. This is achieved, for example, by notching or pressing in the outside of the pole cap 10 in the region of the connecting sections 25 or below the connecting sections 25, thereby creating an electrically conductive connection between the pole cap 10 and the conductor 20.

[0077] Figs. 8a, 8b, and 8c show schematic detailed views illustrating a method according to a second embodiment of the invention. In contrast to the tension dome 30 shown in Fig. 2, this embodiment illustrates a tension dome 30 which, through a rotational movement and / or a translational movement of the tension dome 30, can form a mechanical operative connection to the arrester 20 in order to be able to pull it against the pole cap 10 on the inside.

[0078] For the sake of simplicity, the tension dome 30 shown is designed to be rotatable about a rotation axis R and has an eccentrically shaped receiving section 34 and driver 35. The receiving section 34 is designed as a recess, and the driver 35 delimits the end of the receiving section 34. The driver 35 acts as a support surface for the arrester 20. After inserting the tension dome 30 into the opening 12, the receiving section 34 is located at a common axial height or depth with the arrester 20 and the pole cap 10. This step is shown in Fig. 8a.

[0079] In a subsequent step, illustrated in Fig. 8b, the tension mandrel 30 is rotated along the rotation axis R, for example, by 90° to 180°, allowing the driver 35 to hook onto the arrester 20. The arrester 20 and the pole cap 10 thus protrude into the receiving section. Subsequently, pulling the tension mandrel 30 out of the opening 12 with the tensile force F enables the zero gap to be adjusted and the arrester 20 to be pressed against the pole cap 10, thereby ensuring, for example, reliable welding of the two components 10, 20. This step is shown in Fig. 8c. After welding the arrester 20 to the pole cap 10, the tension dome 30 can be rotated further or backward along the rotation axis R in order to align the driver 35 with the opening 12 and to enable removal of the tension dome 30 from the electrochemical cell 100.

[0080] Figs. 9a, 9b, and 9c show schematic detailed views illustrating a method according to a third embodiment of the invention. In contrast to the previously shown embodiments, in the first step, illustrated by Fig. 9a, a tension mandrel 30 is inserted, which can remain permanently in the battery cell 100 in sections.

[0081] The tension dome 30 has a carrier 35 formed at its end. The carrier 35 acts as a support surface for the arrester 20 in the region of the opening 23 and remains permanently in the battery cell 100. Depending on the design, the carrier 35 can lock the arrester 20 in one or more directions or limit its movement. In the illustrated embodiment, for example, a limitation occurs opposite to a direction of the force F acting on the tension dome 30 to eliminate the initial gap 13.

[0082] The tension dome 30 can, for example, be arranged on the arrester 20 before the pole cap 10 is mounted. The pole cap 10 is positioned on the arrester 20 such that the previously inserted tension dome 30 is guided through the opening 12. In an alternative embodiment, the tension dome 30 can be a component of the arrester 20. An integral unit can be manufactured from a tension dome 30 and the arrester 20 or can be formed by a material-to-material or form-fitting connection of a tension dome 30 to an arrester 20. Thus, the tension dome 30 can be welded, canted, glued, crimped, or similarly configured to the arrester 20. This ensures particularly optimal electrical conductivity between the tension dome 30 and the arrester 20.

[0083] The tension dome 30 further comprises an outer tube section 31 and a spreading section 32. In the illustrated embodiment, the spreading section 32 is arranged downstream of the driver 35 in the direction of the outer side A.

[0084] The expansion section 32 is positioned at a distance from the conductor 20, allowing it to be deformed within the opening 12 of the pole cap 10 or outside the opening 12 of the pole cap 10. Furthermore, the tension dome 30 has a predetermined breaking point 36 located downstream of the expansion section 32.

[0085] Fig. 9b illustrates a step of the method in which the force F is applied to the tension dome 30. This eliminates the initial gap 13 between the arrester 20 and the inner side 11 of the pole cap 10. This tension between the components 10, 20, 30 is maintained, and the expansion section 32 is expanded. This can be achieved, for example, by inserting a not-shown expansion element in the form of a bolt through the tube section 31, which results in an increase in cross-section due to plastic deformation of the expansion section 32. The force N required for plastic deformation is shown schematically and is applied to the tension dome 30 in opposition to the tensile force F. Due to the deformation of the expansion section 32, the tension dome 30 fulfills the function of a rivet and connects the arrester 20 to the pole cap 10.Depending on the design, the pipe section 31 can open in the area of ​​the expansion section 32 into an integrated opening 12" of the tension dome 30, which can be used as a filling opening for filling an electrolyte.

[0086] Subsequently, a protruding section 31' of the tension dome 30 can be removed along the predetermined breaking point 36. Overstressing the predetermined breaking point 36 can be caused by tilting and / or twisting the section 31' of the tension dome 30 relative to the pole cap 10 or the plastically deformed expansion section 32. This step is illustrated in Fig. 9c. Thus, a permanent mechanical connection is formed between the tension dome 30, the conductor 20, and the pole cap 10.

[0087] A section 31" of the tension dome 30 that remains permanently in the battery cell 100 can be mechanically machined in the region of the plastically deformed expansion section 32 in order to prepare an outer surface of the pole cap 10 according to the requirements.

[0088] The remaining section 31" of the tension dome 30 forms, in addition to the mechanical connection, an electrically conductive connection between the arrester 20 and the pole cap 10. Optionally, the deformed expansion section 32 of the remaining section 31" and the transition area to the pole cap 10 can be machined by milling, drilling, grinding, welding, and the like. For example, the section 31" can be planed by sliding friction, such as the flow drilling process.

Claims

CLAIMS 1 . Method for connecting an arrester (20) to an inner side (11) of a pole cap (10) of an electrochemical cell (100), wherein a tension dome (30) is pushed through an opening (12, 12') of the pole cap (10) and / or through an opening (23) of the arrester (20), wherein the tension dome (30) is designed to form a mechanical connection between the tension dome (30) and the arrester (20) at least temporarily at a section (31") or is mechanically connected to the arrester (20), wherein a force (F) directed out of the opening (12) of the pole cap (10) is set on the tension dome (30) and the arrester (20) is pressed against the inner side (11) of the pole cap (10), wherein the arrester (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.

2. Method according to claim 1, wherein the tension dome (30) is moved through an opening (23) of the arrester (20) in the direction of an outer side (A), wherein the tension dome (23) is mechanically, in particular positively, hooked to the arrester (20) at its end in the region of the opening (23); or wherein the tension dome (30) is spread at its end in the region of the opening (23) of the arrester (20) mechanically or by overpressure, in particular pneumatically or hydraulically, or by negative pressure in order to form a temporary or permanent mechanical connection between the tension dome (30) and the arrester (20).

3. Method according to claim 2, wherein the tension dome (30) has an outer tube section (31) which has an end-side spreading section (32), wherein the spreading section (32) is acted upon by the Pipe section (31) is enlarged at least in some areas by means of overpressure or by pressing in a bolt or an expansion element (33).

4. The method according to claim 3, wherein the spreading section (32) is a spreading element (33), wherein the expansion element (33) is pulled or pressed mechanically or by negative pressure into the outer tube section (31) in order to enlarge the expansion section (32) at least in some areas.

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

6. The method according to claim 5, wherein the tension dome (30) has a receiving section (34) and / or a driver (35).

7. The method according to claim 6, wherein the driver (35) of the tension dome (30) is designed to mechanically hook with the arrester (20) in the region of the opening (23).

8. Method according to one of claims 1 to 7, wherein the tension dome (30) is designed integrally with the arrester (20) or is connected to the arrester (20), wherein the arrester (20) is moved to the inside (11) of the pole cap (10) in such a way that the tension dome (30) is guided through the opening (12) of the pole cap (10) to the outside (A).

9. Method according to one of claims 1 to 8, wherein the arrester (20) is connected to the pole cap (10) in a form-fitting or material-fitting or friction-fitting manner by the spread-out section (32) of the tension dome (30).

10. Method according to one of claims 1 to 9, wherein the tension mandrel (30) has a predetermined breaking point (36), wherein after the spreading section (32) has been spread, the tension mandrel (30) is subjected to a tensile force and / or a torque such that at least a section (31') of the tension mandrel (30) is severed along the predetermined breaking point (36).

11. Method according to one of claims 1 to 10, wherein the pole cap (10) has at least one connection opening (12'), wherein a line weld or a hole weld or a soldered connection is introduced through the at least one connection opening (12') in order to form a material connection between the arrester (20) and the pole cap (10).

12. Method according to one of claims 1 to 8, wherein after connecting the arrester (20) to the pole cap (10), the tension dome (30) is removed from the opening (12) designed as a filling opening and the opening (12) is used to fill an electrolyte, or wherein the tube section (31) of the tension dome (30) opens into an opening (12") designed as a filling opening, which is used to fill the electrolyte.

13. Method according to one of claims 1 to 9, wherein the tension dome (30) is spread and / or hooked at the end in the region of a recess (24) of the arrester (20) designed as a blind hole or as an extruded profile in order to mechanically couple it. Method according to one of claims 1 to 11, wherein the arrester (20) has at least one lateral connecting section (25) which substantially corresponds to an inner contour of the pole cap (10), in particular in the region of the inner side (11), wherein the arrester (20) is connected to the pole cap (10) by plastic deformation (42) of the pole cap (10) in the region of the connecting section (25). Method according to one of claims 1 to 12, wherein the arrester (20) is connected to the pole cap (10) at least in regions by a through-weld (40) through the pole cap (10) and / or by a joint welding between the spreading section (32) and the opening (12) of the pole cap (10), in particular in the region of a predetermined breaking point (36).

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