Method for connecting an arrester to the electrode cap of a battery cell.

Abstract

The present invention relates to a method for connecting an arrester (20) to the inside (11) of an electrode cap (10) of an electrochemical cell (100), wherein a tension mandrel (30) is pushed through an opening (12, 12') of the electrode cap (10) and / or through an opening (23) or recess (24) of the arrester (20), and the tension mandrel (30) is designed to form at least temporarily a mechanical connection between the tension mandrel (30) and the arrester (20) at a portion (31"), or is mechanically connected to the arrester (20), and an outward force (F) from the opening (12) of the electrode cap (10) is set on the tension mandrel (30), pushing the arrester (20) against the inside (11) of the electrode cap (10), and the arrested arrester (20) pushed against the inside (11) of the electrode cap (10) is connected to the electrode cap (10) in a particularly conductive manner.

Description

Technical Field

[0001] The present invention relates to a method for connecting an arrester inside an electrode cap of an electrochemical cell.

Background Art

[0002] In the manufacture of an electrochemical storage device such as a lithium-ion battery, for example, several alternating layers consisting of an anode, a cathode, and a separator are usually arranged in the form of a cell stack. Each anode and each cathode are electrically contacted by each arrester. For example, when two cell stacks are used, a U-shaped arrester with two ends facing the two cell stacks and the front facing the inside of the electrode cap is used. The arrester functions as an electrical interface between the cell stack and the electrode cap.

[0003] Due to the arrangement of the electrode caps on both sides or opposite each other, the first electrode cap can be welded or soldered to the arrester of the cell stack in a normal and technically unchallenging manner. The second electrode cap can no longer be directly connected to the arrester. For this purpose, a long connecting wire has to be provided between the second arrester and the cell stack, which means that a longer connecting wire is required due to the assembly of the housing volume.

Summary of the Invention

[0004] Therefore, the present invention has the object of creating a method for connecting an arrester, particularly a second arrester to be connected, by means of which the volume of the cell housing can be minimized. This object is achieved by the features described 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 an arrester inside an electrode cap of an electrochemical cell is provided.

[0006] In one step, the tension mandrel is pushed through an opening, such as the filling opening of the electrode cap, and / or through an opening or recess of the arrester. The arrester's opening may be designed to correspond to the opening of the electrode cap. Depending on the design of the tension mandrel, if the tension mandrel is mechanically or integrally connected to the arrester, the arrester's opening does not need to be considered.

[0007] The tension mandrel may be extended at a portion of the arrester's end to form at least a temporary mechanical connection between the tension mandrel and the arrester, or it may be mechanically connected to the arrester. Depending on the design, the tension mandrel may be permanently connected to the arrester at its end.

[0008] In a further step, a force is applied to the tension mandrel, moving outward from the filling opening of the electrode cap. This pushes the arrester against the inside of the electrode cap. By pushing or pulling the arrester against the inside of the electrode cap, the initial gap between the inside of the electrode cap and the arrester is eliminated, thus preparing it optimally for the subsequent bonding step. In the bonding step, the arrester is then connected to the electrode cap, particularly in a conductive manner.

[0009] This method can be used to establish a so-called zero gap between the electrode cap and the arrester in order to implement a process-reliable connection between the electrode cap and the arrester. In particular, this method can be used to pull or push the arrester from the outside relative to the electrode cap without exerting any damaging force on at least one cell stack connected to the arrester.

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

[0011] According to one embodiment, the tension mandrel is moved outward through the opening of the arrester. The tension mandrel is mechanically hooked onto the arrester at its end in the region of the opening, particularly in a shape-conforming manner. Alternatively, the tension mandrel is inserted through the electrode cap and the arrester opening to form a temporary or permanent mechanical connection between the tension mandrel and the arrester, and is expanded at its end in the region of the arrester opening, mechanically, or by overpressure, particularly by air pressure or liquid pressure, or by vacuum. The end of the tension mandrel can be expanded in various ways to fix the arrester in place and thus fix it immovably with respect to the tension mandrel in at least one direction. Depending on the design, the tension mandrel can hook behind the arrester or form a temporarily fixed connection with the arrester in order to allow the arrester to move relative to the electrode cap. Thus, the tension mandrel can be expanded or enlarged at the opening or recess of the arrester, or behind or below the opening, in order to allow the arrester to move along at least one direction.

[0012] The tension mandrel can be expanded at its end in such a way that this end portion deforms and acts like a rivet, so to speak, to form a mechanical connection between the arrester and the electrode cap.

[0013] In particular, a tension mandrel may be designed to pull the arrester, thus pushing or moving it against the inside of the electrode cap.

[0014] In a further embodiment, the tension mandrel has an outer tube portion having an end flared portion. Preferably, the flared portion is expanded in at least some area by the application of excessive pressure to the tube portion or by pushing a bolt. This allows the tension mandrel to be expanded at the end in a technically simple manner. In this case, the flared portion may be designed to be elastic in at least some area to increase or decrease the dimension of the tension mandrel lateral to the pulling direction of the arrester. The tension mandrel may function as a tool in which the flared portion is temporarily expanded. In an alternative or additional design, the tension mandrel may function as a connecting means in which the flared portion can be permanently expanded.

[0015] If the flaring portion has a flaring element, and the flaring element is pulled or pushed into the outer pipe portion by mechanical or vacuum to expand the flaring portion in at least some area, the tension mandrel can be a particularly simple technical design. Thus, the flaring element can be separated from the outer pipe portion by mechanical action or excessive pressure to reduce the size of the flaring portion again. Depending on the design, a return spring may be provided that can automatically separate the flaring element from the outer pipe portion in the direction of the tension mandrel's pull to reduce the size of the flaring portion.

[0016] The spreading portion can be extended by the spreading element along at least one spatial direction that is lateral to the pulling direction of the tension mandrel. Depending on the design, the spreading element may be rotationally symmetric, thereby enabling uniform expansion of the spreading portion.

[0017] According to an alternative embodiment, the mechanical connection between the tension mandrel and the arrester is formed by the rotational and / or translational motion of the tension mandrel. This allows the tension mandrel to be pushed through the opening by rotational motion or lateral or pivotal motion in such a way that it can be pushed against the inside of the electrode cap to engage the arrester. This type of tension mandrel can also be particularly easy to implement from a technical standpoint and can be integrated into automated processes.

[0018] According to a further embodiment, the tension mandrel has a receiving portion and / or a driver. The receiving portion is designed to receive a portion of the arrester laterally. The driver may conveniently protrude beyond the receiving portion and thereby hook onto the rear of the arrester. The receiving portion and the driver may be eccentric in shape with respect to the axis of rotation of the tension mandrel.

[0019] For example, the tension mandrel may be pushed through the opening until the arrester and electrode cap are at the same height as the receiving portion. Optional limiting elements of the tension mandrel may limit or control the required insertion depth of the tension mandrel through the opening. The tappet functions as an opposing or contact surface for the arrester.

[0020] Depending on the design, the receiving portion and driver of the tension mandrel may form a screw shape or thread shape. Thus, the tension mandrel inserted into the opening can be rotated, thereby, by rotation along the axis of rotation of the tension mandrel, the effective position of the driver moves inward toward the electrode cap, and thus pushes the arrester and electrode cap toward each other. Alternatively, this can be achieved by threads on the tension mandrel outside the electrochemical cell, which change the axial or depth position of the tension mandrel by rotation of at least a portion of the tension mandrel.

[0021] The actuator can realize rotational and / or translational motion of the tension mandrel. Optionally, signals or measurement data from sensors and / or end stoppers can be used to ensure a specified contact pressure of the arrester on the inside of the electrode cap. A control unit can realize the cooperative action between the sensor or end stopper or end contact and the actuator.

[0022] Similarly, the control unit may also control the action of the tension mandrel by vacuum or overpressure. In this case, further sensors, such as pressure sensors and similar sensors, may be used for the targeted control of the tension mandrel.

[0023] In another convenient design, a tension mandrel may be pushed through the arrester opening before the battery cell or electrochemical cell is installed, so that the end of the tappet can catch on the rear of the arrester opening or other part, or interact in a manner of conforming or friction. The arrester may then be moved toward the electrode cap using the tension mandrel, and the tension mandrel may also be guided through the electrode cap opening so that the arrester can be pulled inward toward the electrode cap after the battery cell is assembled or the cell housing is closed. The tension mandrel may remain, at least partially, within the completed battery cell.

[0024] According to further embodiments, the driver of the tension mandrel is designed to mechanically engage with the arrester in the area of ​​the opening. The driver may be designed as, for example, a thickened section, an end T-piece, a head or screw head, a spring, a lateral bulge, etc. The driver is used to prevent the tension mandrel from sliding freely through the opening of the arrester.

[0025] According to a further embodiment, the pulling mandrel is integrally formed with or connected to the arrestor. In addition to the pulling mandrel mechanically interacting with the arrestor, it is also adhesively bonded, welded, soldered, crimped, or clamped to form a connection between the pulling mandrel and the arrestor that allows a force to be applied to the pulling mandrel to pull the arrestor against the electrode cap.

[0026] For example, a pulling mandrel firmly connected to the arrestor by welding or soldering can be considered, for example, a pulling mandrel designed integrally with the arrestor. In the manufacturing process, the integral assembly consisting of the pulling mandrel and the arrestor can also be formed, for example, by injection molding.

[0027] Advantageously, the arrestor is moved inside the electrode cap so that the pulling mandrel is guided outwards through the opening of the electrode cap.

[0028] This allows the pulling mandrel to remain partially within the battery cell. After connecting the electrode cap to the arrestor, the portion of the pulling mandrel protruding from the opening of the electrode cap can be removed by milling, cutting, tearing, etc. Depending on the design, the connection between the arrestor and the electrode cap can be established via a direct connection between the arrestor and the electrode cap and / or via an indirect conductive connection that reaches the arrestor through the portion of the pulling mandrel remaining in the battery cell from the electrode cap.

[0029] According to a further embodiment, the arrester is connected to the electrode cap by means of the spreading part of the tension mandrel in a form-fitting or material-bonded or frictionally fixed manner. For example, the arrester can be connected to the electrode cap by laser welding, tab welding, so-called e-filling, riveting, canting, pressing, etc. This enables the realization of a conductive connection between the electrode cap and the arrester in various ways. In this case, the tension mandrel can alternatively or additionally function as a rivet or a blind rivet. The driver can be coupled to the arrester and the spreading part can be coupled to the electrode cap, whereby the arrester can be connected to the electrode cap in a technically very simple manner. In this case, after the tension is applied to the protruding part of the tension mandrel, the spreading part is widened, especially in a fan-shaped manner or widened in width. It can advantageously be deformed

[0030] A tension mandrel integrally formed with the arrester can be used in the same way. In this case, the spreading part can be positioned away from the arrester so as to enable it to be deformed inside or outside the opening of the electrode cap.

[0031] Furthermore, the holes can be welded through the electrode cap and / or in the region of the opening of the electrode cap, for example by laser welding.

[0032] If the tension mandrel has a predetermined breaking point, the part of the tension mandrel protruding from the battery cell can be removed particularly easily. It is advantageous if a pulling force and / or a rotational force is applied to the tension mandrel in such a way that at least a part of the tension mandrel separates along the predetermined breaking point after the spreading part has been widened. This means enables the removal of the protruding tension mandrel, with a part remaining permanently inside the battery cell, without additional tools or with a minimum amount of tools.

[0033] The remaining separated edge or stub of the tension mandrel can be removed by welding, milling, grinding, or the like.

[0034] The arrester may be tilted or pressed, for example, by notching or deforming the electrode cap in at least one lateral portion. This is achieved, in particular, by plastic deformation in at least several areas of the electrode cap, resulting in a mechanical connection between the electrode cap and the arrester. For this purpose, the electrode cap may also engage with the arrester internally so as to form electrical contacts between the electrode cap and the sidewall of the arrester.

[0035] In a further embodiment, the electrode cap has at least one connection opening. Preferably, a wire weld, plug weld, or solder connection is introduced through at least one connection opening to form a material bond between the arrester and the electrode cap. This means ensures that a material bond is formed between the electrode cap and the arrester. In addition, the formation of such a connection can be reliably verified as part of a quality control process.

[0036] If, after connecting the arrester to the electrode cap, the tension mandrel is removed from the filling opening and the filling opening is used to fill the electrolyte, this process can be used in the automated manufacturing of cells or battery cells.

[0037] Alternatively, the tubular portion of the tension mandrel protruding from the electrode cap opens into an opening designed as a filling opening used for filling with electrolyte. This means allows the tension mandrel to be used as a filling nozzle before the protruding portion of the tension mandrel is cut off. This means also allows the tension mandrel to be used for various possible operations in battery cell manufacturing.

[0038] In particular, depending on the design, several tension mandrels used in parallel may simultaneously fix several arresters and press them against several electrode caps internally. Each electrode cap and arrester can then be coupled simultaneously in a conductive manner by several parallel connections. This results in optimal scalability of the process for rapid continuous production of battery cells. This means can be equally well implemented by tension mandrels that remain permanently within the battery cell or by tension mandrels that are temporarily inserted.

[0039] After the flared portion of the tension mandrel is reduced in size again, the temporarily inserted tension mandrel is then pulled out of the opening or filling opening so that the cell can be filled. This means that the filling opening can be used for several tasks, namely tightening the arrester and filling the cell. A temporarily inserted tension mandrel can essentially use its flared portion to secure the arrester. In contrast, a tension mandrel whose portion remains permanently inside the battery cell can use its flared portion to permanently secure the electrode cap, thus achieving the function of a rivet.

[0040] In a further embodiment, the filling opening is sealed in a liquid-tight manner after the electrolyte has been filled. This step of the process can be easily accomplished, for example, by inserting a plug or a blind plug, or by closing the filling opening by a method of material aggregation.

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

[0042] According to further embodiments, the tension mandrel is enlarged and / or hooked at its ends in the region of a recess in the arrester, designed as a blind hole or an extruded profile, to mechanically connect it. This means that the use of a cost-effective extruded profile conformed to the dimensions of the electrode cap means that the arrester can be manufactured in a particularly simple manner. Such an extruded profile can be used for both temporary and permanent tension mandrels. In the case of a temporarily inserted tension mandrel, the enlarged portion may engage with a portion of the profile so that the arrester can be moved from the outside. In the case of a permanently installed tension mandrel, a portion of which remains inside the battery cell, a permanently formable enlarged portion or driver may interact with a portion of the profile in a shape-fit or friction-fit manner so that the arrester can be moved from the outside.

[0043] The use of blind holes and recesses or grooves in the extruded profile can simultaneously allow the arrester to be attached to the electrode cap and the cell to be filled with electrolyte.

[0044] If the arrester has at least one lateral connection portion that essentially corresponds to the inner contour of the electrode cap on the inside, the arrester can be electrically connected to the electrode cap in a technically simple manner. In this case, the arrester is connected to the electrode cap by plastically deforming the electrode cap in the region of the connection portion. For example, notching or pressing inside the electrode cap on the outside of the region of the connection portion can create a conductive connection between the electrode cap and the arrester.

[0045] In at least some areas, when an arrester is connected to an electrode cap by through-welding through the electrode cap, the arrester can be connected to the electrode cap in a conductive manner, particularly easily by technical means. For example, an arrester that is pulled or pushed inward into the electrode cap by a tension mandrel can be connected in a materially integrated manner along a through-weld made by laser welding.

[0046] In alternative or additional designs, the arrester is connected to the electrode cap in a conductive manner by welding the joint between the spreading portion and the opening of the electrode cap, particularly in the region of a predetermined fracture point. This allows the arrester to be indirectly connected to the electrode cap via a portion of a tension mandrel, such as between the tappet and the spreading portion. In addition to the forces acting between the arrester, driver, spreading portion, and electrode cap, optimal or additional welding or soldering connections may improve the electrical contact resistance between the components.

[0047] Alternatively or additionally, welded connections may be formed between the arrester and the electrode cap in the region of the edge of the opening or filled opening. This can be done with or without a permanently used tension mandrel or portion of a tension mandrel.

[0048] This method may, if convenient, be carried out using one or more tension mandrels. In this case, a tension mandrel inserted only temporarily from the outside, a tension mandrel that remains only permanently, or a combination of tension mandrels inserted temporarily and permanently may be used.

[0049] Some examples of the present invention are described in more detail in the following drawings. [Brief explanation of the drawing]

[0050] [Figure 1] This is a schematic cross-sectional view of a battery cell having two cell stacks connected in parallel and electrode caps positioned on opposite sides of each other. [Figure 2] This is a detailed view B of Figure 1, showing the method according to the first embodiment of the present invention. [Figure 3] This is a detailed diagram showing an arrester connected to an electrode cap by through welding. [Figure 4] This is a detailed diagram showing an arrester connected to an electrode cap by plug welding. [Figure 5] Figure 1 is a top view of the electrode cap of the battery cell shown. [Figure 6a] This is a detailed diagram of a battery cell with an arrester designed as an extruded profile. [Figure 6b] This is a detailed diagram of a battery cell with an arrester designed as an extruded profile. [Figure 7a] This is a detailed diagram of a battery cell illustrating the connection of an arrester to the electrode cap due to plastic deformation. [Figure 7b] This is a detailed diagram of a battery cell illustrating the connection of an arrester to the electrode cap due to plastic deformation. [Figure 8a] This is a schematic detail diagram showing a method according to a second embodiment of the present invention. [Figure 8b] This is a schematic detail diagram showing a method according to a second embodiment of the present invention. [Figure 8c] This is a schematic detail diagram showing a method according to a second embodiment of the present invention. [Figure 9a] This is a schematic detail diagram showing a method according to a third embodiment of the present invention. [Figure 9b] This is a schematic detail diagram showing a method according to a third embodiment of the present invention. [Figure 9c] This is a schematic detail diagram showing a method according to a third embodiment of the present invention. [Modes for carrying out the invention]

[0051] In the diagram, the same reference number represents the same element or component. The size and relative position of elements in the diagram are not necessarily drawn to scale, and some of these elements are enlarged and positioned for clarity. Furthermore, the specific shapes of the depicted elements are not intended to convey any information about the actual shape of the individual elements, but are chosen solely to facilitate recognition within the diagram.

[0052] Figure 1 shows a schematic cross-sectional view of an electrochemical cell or battery cell 100 having two cell stacks 101, 102 connected in parallel and electrode caps 10 positioned opposite each other. The battery cell 100 has electrode caps 10 positioned on both sides or in opposite directions. The two cell stacks 101, 102 are housed in a cell housing 110, each electrically connected to an arrester 20 via connecting wires 103 at its front. The cell housing 110 may have, for example, a rectangular or square cross-section and may be directly or indirectly closed at its front end by the electrode caps 10 to receive the electrolyte.

[0053] At least one filling opening 12 extending through at least one electrode cap 10 is provided to introduce electrolyte into the housing volume V of the battery cell 100.

[0054] In the illustrated example, the arrester 20 is designed as a U-shaped arrester and has two legs 21, each in electrical contact with the cell stacks 101 and 102. The legs 21 of the arrester 20 are connected to each other by a cross piece 22. The cross piece 22 is connected in a conductive manner to the inside 11 of the electrode cap 10, so that the cell stacks 101 and 102 are designed to be conductive with the electrode cap 10. These details are shown, for example, in Figure 2.

[0055] The first arrester 20 can be electrically connected to the first electrode cap 10 in a technically simple manner. However, the subsequent connection of the second arrester 20 to the second electrode cap 10 requires additional means, which will be described in more detail below. To avoid internal damage to the battery cell 100, no direct force can be applied to the cell stacks 101, 102.

[0056] For reliable electrical connection between the arrester 20 and the electrode cap 10, the initial gap 13 having a distance d between the inside 11 of the electrode cap 10 and the arrester 20 should be eliminated, and a so-called zero gap should be formed. Figure 2 shows a method according to an embodiment of the present invention, and Figure 1 shows a detailed diagram B illustrating a method for forming a zero gap. For clarity, internal components such as the cell stacks 101, 102 and connecting wires 103 are not shown in Figure 2 and the following diagrams.

[0057] In one step of the method according to the present invention, a tension mandrel 30, which can be expanded at its end, is pushed from the outside or outside A through an opening 12 in the electrode cap 10. In the illustrated embodiment, the opening 12 is designed as a filling opening for introducing electrolyte into the housing volume V. The tension mandrel 30 is also pushed through or into an opening 23 or recess 24 in the arrester 20 corresponding to the opening 12. An arrester 20 having such a recess 24 is shown, for example, in Figure 5. In the illustrated example, the tension mandrel 30 remains temporarily inside or on the components 10, 20 so that the zero gap can be adjusted.

[0058] Next, the tension mandrel 30 is expanded at its end within the region of the opening 23 or recess 24 of the arrester 20 in order to form a temporary mechanical connection between the tension mandrel 30 and the arrester 20.

[0059] In a further step, a force F directed outward from the opening 12 of the electrode cap 10 is set on the tension mandrel 30. This pushes the arrester 20 against the inside 11 of the electrode cap 10.

[0060] Pressing the arrester 20 against the inner surface 11 of the electrode cap 10 eliminates the initial gap 13 between the inner surface 11 of the electrode cap 10 and the arrester 20, thus optimally preparing for the subsequent bonding step. Next, in the bonding step, the arrester 20 is connected to the electrode cap 10 in a conductive way, preferably also in a mechanical way.

[0061] The tension mandrel 30 has an outer tubular portion 31 and an end flared portion 32. In the illustrated embodiment, a flared element 33 is positioned in the flared portion 32. The flared element 33 is designed to be a cone that tapers in the direction of the force F and can be pulled into the tubular portion by mechanical action or vacuum in such a way that the end flared portion obtains an increase in cross-section. The arrows in the pipe portion 31 schematically illustrate the movement of the flared element 33. This cross-sectional expansion results in the flared portion 32 being fixed into the opening 23 of the arrester 20.

[0062] The fixing mechanism may be designed as a limitation of the movement of the arrester 20 by at least partial shape conformity of the spreading portion 32. For example, in Figure 2, the spreading portion 32 catches below and behind the opening 23 of the arrester 20 so that the arrester 20 can be pulled against the inside 11 of the electrode cap 10.

[0063] As a result of the force F acting on the arrester 20, the force is not simultaneously exerted on the cell stacks 101 and 102. Preferably, the disconnection between the cell stacks 101 and 102 and the arrester 20 is achieved by a connecting wire 103. For this purpose, the connecting wire 103 may be designed to be slightly longer than, for example, the distance between the leg 21 of the arrester 20 and the end faces of the cell stacks 101 and 102.

[0064] Figure 3 shows a detailed diagram illustrating the arrester 20 connected to the electrode cap 10 by a through-weld 40. An alternative or additional option for material fixing connection between the electrode cap 10 and the arrester 20 is shown in Figure 4, which shows a detailed diagram of the arrester 20 connected to the electrode cap 10 by a plug weld 41.

[0065] One or more welds 40 are manufactured, for example, by laser welding. After setting the gap between the arrester 20 and the electrode cap to zero, a welding apparatus (not shown) may be positioned outside the electrode cap 10 and may operate in at least some area.

[0066] The welded joint 40 may, for example, surround a point, line, and / or closed area on the electrode cap 10. Because the thickness of the material of the electrode cap 10 is relatively small, the crossbar 22 of the arrester 20, which is installed behind the electrode cap 10, is also melted and thus firmly connected to the electrode cap 10.

[0067] The welded hole 41 may be formed, for example, at the edge of the filling opening 12 or in the region of the connecting opening 12' (see Figure 5). In this process, the edge region of the filling opening 12 is melted by the welding process in order to connect the electrode cap 10 to the arrester 20. This still leaves a fluid channel for filling the battery cell 100 with electrolyte.

[0068] As shown in Figure 5, if further openings or connection openings 12' are used, they may be used to set welding points, for example by laser welding, and thus to completely close the connection openings 12'. The corresponding connection openings 12' may preferably be designed as blind holes. In this case, the recess or indentation 24 of the arrester 20, or the crossbar 22 of the arrester 20, is located behind the opening 12' of the electrode cap 10.

[0069] Furthermore, Figure 4 shows a detailed view of an arrester 20 connected to the electrode cap 10 by punch welding, where the arrester 20 can be pulled onto the inside 11 of the electrode cap 10 through a tension mandrel 30 in a recess or depression 24, rather than in a corresponding opening 23. The material-fixing connection between the depression 24 and the electrode cap 10 is specifically designed to prevent fluid leakage and does not require an additional closure 14 (see Figure 3). However, the filling openings 12, 23 require a closure 14 after the battery cell 100 is filled.

[0070] The closure 14 may be a reversible or irreversible closure, allowing the housing volume V to be opened again or permanently sealing the battery cell 100. For example, the closure 14 may be designed as a plug, a screw cap, a molten seal, etc.

[0071] In alternative or additional designs, the recess 24 may have a female thread so that a threaded connection can be formed between the electrode cap 10 and the arrester 20 by a screw (not shown) as an alternative to a welded connection.

[0072] The recesses 24 or depressions may be created in the cross piece 22 of the arrester 20 by a material removal or forming process, such as punching. At the same time, the legs 21 of the arrester 20 may also be formed, for example, by a punching or forming process.

[0073] Figure 5 shows a top view of the electrode cap 10 of the battery cell 100 shown in Figure 1. The electrode cap 10 has a centrally located filling opening 12 and two openings 12' located above the recess 24 of the arrester 20. The filling opening 12 is located above the corresponding opening 23 of the arrester 20 and forms a fluid channel into the housing volume V of the battery cell 100.

[0074] In the illustrated embodiment, for example, the opening 12' designed as a blind hole may be used to form a connection between the electrode cap 10 and the arrester 20. In order that the introduced weld seam or weld point has the smallest possible protrusion, the electrode cap 10 may have a recess or fading (not shown) in the area of ​​the opening 12'.

[0075] Figures 6a and 6b show detailed views of a battery cell 100 having an arrester 20 designed as an extruded profile. Figure 6a shows the arrester 20 consisting of an extruded profile having a V-shaped recess or indentation 24. In comparison, in Figure 6b, the indentation 24 is T-shaped.

[0076] The corresponding recess 24 extends along the entire length of the arrester 20 along one spatial direction. The cross piece 22 of the arrester 20 is blocked by or has the recess 24. Such an arrester 20 can be manufactured in a technically simple manner in which a pre-fabricated extruded profile is cut to a predetermined length.

[0077] A recess 24 extending along the entire length or width of the arrester 20 forms a blind hole in the opening 12' of the electrode cap 10, although an additional closure 14 is convenient for preventing electrolyte leakage. This design is schematically shown in Figure 6b.

[0078] Figures 7a and 7b show detailed views of the battery cell 100 to illustrate the connection of the arrester 20 to the electrode cap 10 by plastic deformation 42. For such a conductive connection between the electrode cap 10 and the arrester 20, the arrester 20 has at least one lateral connection portion 25. In the illustrated embodiment, the connection portion 25 is located on both sides or edges of the arrester 20 in the transition region between each leg portion 21 and the cross piece 22, and this connection portion 25 is formed, for example, as a lateral extension of the cross piece 22.

[0079] The lateral connection portion 25 essentially corresponds to the lateral inner contour of the electrode cap 10. Figure 7b shows the plastic deformation of the electrode cap 10 in the region of the connection portion 25. This is done, for example, by notching the electrode cap 10 on the outside or pressing the electrode cap 10 in or below the region of the connection portion 25, thereby creating a conductive connection between the electrode cap 10 and the arrester 20.

[0080] Figures 8a, 8b, and 8c show schematic detail diagrams illustrating a method according to a second embodiment of the present invention. In contrast to the tension mandrel 30 shown in Figure 2, this embodiment shows a tension mandrel 30 that can form a mechanical connection to the arrester 20 by rotational and / or translational motion of the tension mandrel 30 so that the latter can be pulled inward against the electrode cap 10.

[0081] For simplicity, the illustrated tension mandrel 30 is designed to rotate around a rotation axis R and has an eccentrically shaped receiving portion 34 and driver 35. The receiving portion 34 is designed as a recess, and the tappet 35 separates the receiving portion 34 at its end. The tappet 35 serves as a contact surface for the arrester 20. After the tension mandrel 30 is inserted into the opening 12, the receiving portion 34 is at the same axial height or depth as the arrester 20 and electrode cap 10. This step is shown in Figure 8a.

[0082] In the subsequent step shown in Figure 8b, the tension mandrel 30 is rotated, for example, 90° to 180° along the rotation axis R, allowing the tappet 35 to catch behind the arrester 20. Thus, the arrester 20 and electrode cap 10 protrude into the receiving portion.

[0083] Next, pulling the tension mandrel 30 out of the opening 12 with a tensile force F allows a zero gap to be set, the arrester 20 to be pressed against the electrode cap 10, and thus ensure a secure weld of, for example, two components 10, 20. This step is shown in Figure 8c. After welding the arrester 20 to the electrode cap 10, the driver 35 is aligned with the opening 12, and the tension mandrel 30 may be further rotated along the axis of rotation R, or reversed, to allow removal of the tension mandrel 30 from the electrochemical cell 100.

[0084] Figures 9a, 9b, and 9c show schematic detail diagrams illustrating a method according to a third embodiment of the present invention. In contrast to the examples already shown, the first step shown in Figure 9a uses a tension mandrel 30 that can remain permanently in part within the battery cell 100.

[0085] The tension mandrel 30 has a driver 35 formed at its end. The driver 35 acts as a contact surface for the arrester 20 in the region of the opening 23 and remains permanently within the battery cell 100. Depending on its design, the driver 35 can fix the arrester 20 in one or more directions or restrict its movement. In the illustrated example, for example, there is a restriction in one direction of the force F that eliminates the initial gap 13 acting on the tension mandrel 30.

[0086] The tension mandrel 30 may be positioned on the arrester 20, for example, before the electrode cap 10 is attached. The electrode cap 10 is positioned on the arrester 20 in such a way that the pre-inserted tension mandrel 30 is guided through the opening 12.

[0087] In an alternative embodiment, the tension mandrel 30 may be a component of the arrester 20. In this case, the integrated unit may be manufactured from the tension mandrel 30 and the arrester 20, or may be formed by material fixing or shape fixing connection of the tension mandrel 30 to the arrester 20. Thus, the tension mandrel 30 may be welded, canted, bonded, or crimped to the arrester 20, for example. This ensures particularly optimal conductivity between the tension mandrel 30 and the arrester 20.

[0088] Furthermore, the tension mandrel 30 also has an outer tube portion 31 and a flared portion 32. In the illustrated example, the flared portion 32 is located downstream of the tappet 35 in the outward direction A.

[0089] The flared portion 32 is positioned at a distance from the arrester 20, and therefore the latter can be deformed either inside or outside the opening 12 of the electrode cap 10. Furthermore, the tension mandrel 30 has a predetermined break point 36 located downstream of the flared portion 32.

[0090] Figure 9b shows the steps of the process by which a force F is set on the tension mandrel 30. This eliminates the initial gap 13 between the arrester 20 and the inside 11 of the electrode cap 10. This tension between components 10, 20, and 30 is maintained, and the flaring portion 32 is widened. This can be achieved, for example, by inserting a flaring element (not shown) in the form of a bolt through the tubular portion 31, resulting in an increase in cross-section due to the plastic deformation of the flaring portion 32. The force N required for the plastic deformation is schematically shown and is realized against the tensile force F in the tension mandrel 30. The deformation of the flaring portion 32 causes the tension mandrel 30 to fulfill the function of a rivet, connecting the arrester 20 to the electrode cap 10.

[0091] Depending on the design, the tubular portion 31 may open to an integrated opening 12" within the tension mandrel 30 in the region of the flared portion 32, which can be used as a filling opening for the electrolyte.

[0092] Next, the protruding portion 31' of the tension mandrel 30 can be removed along a predetermined fracture point 36. Overuse of the predetermined fracture point 36 is achieved by tilting and / or twisting the portion 31' of the tension mandrel 30 relative to the electrode cap 10 or the plastically deformed widened portion 32. This step is shown in Figure 9c. Thus, a permanent mechanical connection is formed between the tension mandrel 30, the arrester 20, and the electrode cap 10.

[0093] The portion 31" of the tension mandrel 30 that remains permanently on the battery cell 100 can be machined in the area of ​​the expanded portion 32 which has been plastically deformed to provide the outer surface of the electrode cap 10 according to requirements.

[0094] The remaining portion 31" of the tension mandrel 30 forms not only a mechanical connection but also a conductive connection between the arrester 20 and the electrode cap 10. Optionally, the deformed widened portion 32 of the remaining portion 31" and the transition region to the electrode cap 10 can be machined by milling, drilling, grinding, welding, etc. For example, portion 31" can be planned by sliding friction, such as a flow drilling process.

Claims

1. A method for connecting an arrester (20) to the inside (11) of the electrode cap (10) of an electrochemical cell (100), The tension mandrel (30) is pushed through the opening (12, 12') of the electrode cap (10) and / or through the opening (23) of the arrester (20), The tension mandrel (30) is configured to at least temporarily form a mechanical connection between the tension mandrel (30) and the arrester (20) at portion (31"), or to be mechanically connected to the arrester (20), A method wherein a force (F) outward from the opening (12) of the electrode cap (10) is set on the tension mandrel (30), the arrester (20) is pressed against the inner side (11) of the electrode cap (10), and the arrester (20) pressed against the inner side (11) of the electrode cap (10) is connected to the electrode cap (10) in a particularly conductive manner.

2. The tension mandrel (30) is moved outward (A) through the opening (23) of the arrester (20), The method according to claim 1, wherein the tension mandrel (30) is mechanically, particularly actively, coupled to the arrester (20) at its end within the region of the opening (23); or the tension mandrel (30) is mechanically, particularly by overpressure by air pressure or liquid pressure, or by vacuum, at its end within the region of the opening (23) of the arrester (20) to form a temporary or permanent mechanical connection between the tension mandrel (30) and the arrester (20).

3. The tension mandrel (30) has an outer tube portion (31) with a widened portion (32) at its end, The method according to claim 2, wherein the expanding portion (32) is expanded in at least some area by applying excessive pressure to the pipe portion (31) or by pushing a bolt or expansion element (33).

4. The method according to claim 3, wherein the spreading portion (32) comprises an expanding element (33), the expanding element (33) is pulled or pushed into the outer tube portion (31) mechanically or by vacuum to expand the spreading portion (32) in at least some area.

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

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

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

8. The method according to any one of claims 1 to 7, wherein the tension mandrel (30) is integrated with the arrester (20) or connected to the arrester (20), and the arrester (20) is moved toward the inward (11) of the electrode cap (10) such that the tension mandrel (30) passes toward the outward (A) through the opening (12) of the electrode cap (10).

9. The method according to any one of claims 1 to 8, wherein the arrester (20) is connected to the electrode cap (10) by the widened flared portion (32) of the tension mandrel (30) in a shape-matching, material-matching, or friction-matching manner.

10. The method according to any one of claims 1 to 9, wherein the tension mandrel (30) has a predetermined breaking point (36), and after the spreading portion (32) has spread, the tension mandrel (30) is subjected to tension and / or rotational force in such a manner that at least a portion (31') of the tension mandrel (30) is cut along the predetermined breaking point (36).

11. The method according to any one of claims 1 to 10, wherein the electrode cap (10) has at least one connection opening (12'), and a wire weld, hole weld, or solder connection is introduced through the at least one connection opening (12') to form a material-compatible connection between the arrester (20) and the electrode cap (10).

12. The method according to any one of claims 1 to 8, wherein after connecting the arrester (20) to the electrode cap (10), the tension mandrel (30) is removed from the opening (12) designed as a filling opening, and the opening (12) is used to fill with an electrolyte, or the tubular portion (31) of the tension mandrel (30) opens into the opening (12") designed as a filling opening used to fill with the electrolyte.

13. The method according to any one of claims 1 to 9, wherein the tension mandrel (30) is widened and / or hooked at the end of the region of the recess (24) of the arrester (20), which is designed as a blind hole or an extruded profile for mechanical coupling.

14. The method according to any one of claims 1 to 11, wherein the arrester (20) has at least one lateral connection portion (25) that essentially corresponds to the inner contour of the electrode cap (10), particularly in the inner (11) region, and the arrester (20) is connected to the electrode cap (10) by plastic deformation (42) of the electrode cap (10) in the region of the connection portion (25).

15. The method according to any one of claims 1 to 12, wherein the arrester (20) is connected to the electrode cap (10) in at least some areas by welding (40) through the electrode cap (10) and / or by welding the joint between the flared portion (32) and the opening (12) of the electrode cap (10), particularly in the area of ​​a predetermined fracture point (36).

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