DE102022208963B4 - Method for producing a battery pouch cell - Google Patents

Abstract

The invention relates to a method for producing a battery pouch cell with a cell housing (2) made of film material, which is constructed from two housing parts (1), which merge into one another in one piece at a folding edge (3), the two housing parts (1) being around the Folding edge (3) are folded over and the facing housing part edges (5) are joined together. According to the invention, the following process steps are carried out: a laying process in which an electrode/separator stack (9) and at least one connection valve (19, 21) are placed on a film material blank (17) which consists of the two housing parts (1); a wrapping process in which the sheet material blank (17) is wrapped around the electrode/separator stack (9); a joining process in which the facing housing part edges (5) are joined together to form the cell housing (2); and a vacuum forming process in which the connection valve (19, 21) is connected to a vacuum source (23) so that the cell housing (2) is pulled around the electrode/separator stack (9) using a vacuum effect.

Description

The invention relates to a method for producing a battery pouch cell according to the preamble of claim 1 and a battery pouch cell according to claim 10.

A battery pouch cell has a cell housing made of a film material in a manner known per se. The cell housing is made up of two housing parts, which merge into one another using the same material and in one piece at a folding edge. The two housing parts are folded over at the folded edge, with their opposite housing part edges being joined together, for example, in a heat-sealing process.

In the prior art, the housing part is produced from a composite film web in a deep-drawing process. The deep-drawing process is followed by a laying process in which an electrode/separator stack is placed in one of the two deep-drawn housing parts. This is then followed by a folding process in which the unoccupied housing part is folded over and connected to the other housing part in a heat sealing process.

The housing of the battery pouch cell essentially consists of an aluminum and plastic laminate film, which is made up of various plastic and aluminum layers. In the prior art, it is important that the thickness of the pouch and aluminum layer is not reduced below the required value after deep drawing. For example, the total thickness of the sheet material is nominally 153µm, while the total thickness after forming must be greater than 107µm. The aluminum layer thickness can be nominally 40µm, while the aluminum thickness after forming must be greater than 28µm. Depending on the electrode design, the corner radius is between 0.5 and 1 mm, which makes deep drawing the aluminum laminate a major challenge. The height of the deep-drawn film material is usually around 4 to 8 mm, although it is difficult to deep-draw the film material without folds and cracks.

In addition, the film material can have an HF protective layer. This can be an adhesive used to bond aluminum to nylon and PP layers. It provides stability against HF gas. For better drawability it is possible to use an 80µm aluminum layer. In this case the total thickness of the film is 150µm. The disadvantages are the higher weight and the higher costs.

The capacity of a battery pouch cell known from the prior art is primarily determined by the maximum number of electrodes in the electrode/separator stack that can currently be accommodated in a deep-drawn cell housing made of laminated aluminum foil. The maximum achievable height of the deep-drawn cell housing limits the stack height of the electrode separator stack. If a predetermined drawing depth is exceeded, cracks at the corners and folds under the surface of the hold-down device can occur in the cell housing.

In the state of the art, the variation window of the forming parameters becomes smaller and smaller as the sheet thickness decreases. For example, a greater tendency to form wrinkles requires an increase in the sheet holding force (lower limit), which can lead to cracks in the bottom of the cup when pulled (upper limit). Precise control of the hold-down force is required because the distance between these upper and lower limits decreases as film thickness decreases. Given the tolerance-related fluctuations in sheet thickness, friction conditions and material properties, it is not realistic to obtain drawn components with consistent drawing properties.

In summary, the biggest challenge in forming a cell casing from thin aluminum laminate is the cracks or excessive thinning at the corners. This can lead to electrolyte leakage. If wrinkles are present, this would degrade the sealing performance of the battery pouch cell, meaning venting could be a problem. The current deep drawing process is not the ideal process for producing cell casings from aluminum laminate.

In the prior art, the cell housing also exerts external pressure on the electrode/separator stack. This can cause the separator to bend, which in turn can result in a short circuit between the anode and cathode. External pressure usually occurs when the deep drawing radius is larger than the radius of the electrode and separator corners. Even as the cell expands, pressure is exerted on the separator at the edges. This means that the edges of the separator can be damaged more quickly when inserting the electrode/separator stacks into the cell housing when sealing the housing halves and when inflating the cell housing. It is important to reinforce the edge of the electrode/separator stack within the battery pouch cell.

From the EP 802 033 A1 a generic battery cell is known which is configured to have a structure in which an electrode arrangement comprising a separator arranged between a cathode and an anode, is mounted in a cell housing. From the US 6,040,081 A A battery with two electrodes is known, each of which is connected to a conductive strip. A separator separates the two electrodes, which are surrounded by an insulating cover. From the JP 2011-181388 A A battery pouch cell is known.

The object of the invention is to provide a method for producing a battery pouch cell in which the cell housing can be manufactured in a simple manner compared to the prior art and without the formation of wrinkles and/or cracks.

The task is solved by the features of claim 1 or claim 10. Preferred developments of the invention are disclosed in the subclaims.

The invention is based on a method for producing a battery pouch cell which has a cell housing made of film material. The cell housing is made up of two housing parts, which merge into one another using the same material and in one piece at a folding edge. When assembled, the two housing parts are folded over at the folded edge, with their opposite housing part edges being joined together (for example in a heat sealing process). According to the characterizing part of claim 1, the method has the following process steps: First, in a laying process, an electrode/separator stack and at least one connection valve are placed on a sheet material blank which consists of the two housing parts. This is followed by a wrapping process in which the sheet material blank is wrapped around the electrode/separator stack. A joining process is then carried out in which the facing housing part edges are joined together to form the cell housing. A vacuum forming process is then carried out in which the connection valve is connected to a vacuum source. In this way, the cell housing is pulled around the electrode/separator stack using negative pressure.

According to the invention, the aim is to design the cell housing around the electrode/separator stack and not to fit the stack into a cell housing of a certain size. The latter is the problem with the current practice of using a deep-drawn cell casing. In the prior art, an inconsistent drawing depth leads to an inconsistent quality of the cell housing. On the other hand, in the invention the cell casing is virtually tailor-made for each stack, making it more robust against small but legitimate variations in the thickness of the stack to which the deep-drawn cell casings are extremely sensitive.

Since the stack is packed into the cell casing, it is important that the cell casing exerts a uniform contact force across the entire outer surface of the stack, which is very difficult to ensure with a conventional deep-drawn cell casing. Deflections of the stack components due to forces exerted by the cell housing wall influence the function of the cell.

In the method according to the invention, the film of the cell housing is positioned on a shelf in a first process step. The electrode/separator stack is then placed on the foil and the foil is wrapped around the stack. The film edges are then sealed along the perimeter to form the cell casing. In addition, valves are installed at appropriate locations while the film is being sealed. These valves act as safety valves to limit the buildup of gas pressure during operation. During manufacturing, these valves can be used to create a vacuum in the cell casing and to draw the electrolyte into the cell casing. In this way, with the help of suction pressure, the electrolyte saturates the different layers of the stack and wets the separator and electrodes that may be difficult to access.

Such a process is more likely to be error-free compared to the prior art because the quality of the seal along the periphery of the cell casing is easier to manage than a traditional deep-drawn cell casing, which impacts downstream processing. The electrolyte that fills the vacuum cell casing is of a more uniform amount and the volume of the cell casing that tightly encloses the electrode stacks is of a more uniform shape, size and performance. The reason for this is that the proposed method of manufacturing the cell casing is not affected by the legitimate variations in material properties, thickness of the film, dimensions of the stacks, etc. and is therefore more robust. In addition, the intensity of the vacuum required for vacuum forming is much lower than that required for filling the electrolyte. The evacuation of air from the stacks therefore enables a greater power density of the cell housing.

The main differences between the current concept and the prior art are as follows: The electrode/separator stack and valves are placed on a flat sheet material blank. The stack and the valves are included an adhesive coating that ensures the correct position of the stacks and valves. The empty cell housing half is rotated over the other cell housing half, which has the stack and valves. Both housing part surfaces are sealed by heat sealing or by gluing. The vacuum is created between two housing parts by sucking in air through a compressor. The air is sucked in via a check valve. The vacuum also deforms the film viscoplastically to obtain the final shape. The electrolyte is injected into the cell housing through a second check valve. The electrolyte soaks the electrode and separator stacks. The electrolyte wetting is accelerated by the pump pressure.

The cell with valves then goes through a formation and aging process. During this process, gas is generated which is released through a valve. After the aging process, a new seal is created between the valve and the stacks. A part of the cell casing with the valve is cut off, hemming the cell casing edge, thereby completing the cell.

If the valves can remain in the cell, the above process step is not necessary. The valve can help remove the gas generated during thermal runaway and thus delay it.

It is also possible for only vacuum forming to take place without immediately following electrolyte injection. The electrolyte injection does not have to be done immediately afterwards. In this case, only one inlet for air intake is required. It is also possible to increase the temperature of the cell housing to 80°C. In this case, vacuum forming can take place at lower vacuum pressure.

It is important to reinforce the corners of the cell stack with tape to prevent them from bending during vacuum forming. Instead of the adhesive tape, a lightweight plastic insert can also be used on the corners and sides of the electrode/separator stack. This protects the stack from all sides from bending due to the vacuum pressure.

In summary, the invention has the following advantages: The state of tension in the film material of the cell housing is different in vacuum forming according to the invention than the state of tension in conventional deep drawing. Therefore, there is less risk of wrinkles and cracks forming. The process according to the invention has the advantage that it can be automated in a simple manner in terms of production technology and even sharp corner radii can be achieved. The use of at least one valve helps to eliminate the gas pocket for storing the gas produced in the formation/aging process. This reduces the material consumption of the aluminum laminate film. The valves are reusable when removed from the finished cell. So it is a one-time investment. When the valves remain in the completed cell, they help delay thermal runaway and swelling of the cell due to the release of internal gas pressure. A high capacity of the cell is possible because the stack height of the electrode/separator stack can be increased compared to the prior art. In contrast, in the prior art the stack height is limited due to production technology due to the deep-drawing process. According to the invention, the joining process (i.e. the sealing process) of the cell housing takes place on a flat film material, which means that a qualitatively perfect seal can be produced in a simple manner. This has advantages for ventilation. In particular, the use of a plastic reinforcing frame (instead of adhesive tape strips) provides high rigidity to the edges and corners of the cell stacks. In addition, the plastic reinforcing frame also determines the height of the cell. Electrolyte injection into the vacuum formed bag under pump pressure contributes to faster electrolyte transfer and better wetting of the electrolyte in the electrode/separator stack. According to the invention, the material consumption of the film material in the production of the cell housing can also be reduced compared to the prior art. This also results in an accelerated process time and no need to heat the film material during deep drawing.

No soft adhesive tape is required, as a plastic reinforcing frame consisting of two halves can also be easily mounted on a jelly roll, in which the electrode/separator stack is not made up of individual sheets stacked one on top of the other, but rather as an electrode/separator stack. Separator winding is carried out. The reinforcement frame can be easily mounted on the Jelly roll. In addition, the corners and edges of the cell housing can be produced flawlessly in terms of production technology.

Relevant aspects of the invention are highlighted again in detail below. The electrode/separator stack can thus have at least one reinforcing element, with the help of which the electrode/separator stack remains dimensionally stable during the vacuum forming process, i.e. is not bent due to the negative pressure effect. In a first embodiment variant, the Reinforcing elements can be strips of adhesive tape, with the help of which the sides and / or corners of the cell stack can be stiffened. Alternatively, the reinforcing element can be a circumferential reinforcing frame made of, for example, electrically insulating plastic. The reinforcing frame can consist of two frame parts, between which the battery cell assembly is arranged. The two frame parts can completely surround the sides and corners of the electrode/separator stack in the circumferential direction. Each of these frame parts can have an angular profile in cross section, with a clamping leg that lies on a stack end of the electrode/separator stack, and with an outer leg that delimits the electrode/separator stack laterally outside. The angle profile thus forms an inner corner area that surrounds the edges and corners at the end of the electrode/separator stack.

After the vacuum forming process, a filling process can be carried out in which liquid electrolyte is fed through the connection valve into the interior of the cell housing. The electrolyte can be fed under pressure from an electrolyte reservoir into the cell housing interior using a pump.

After the filling process, a formation and aging process begins, during which the first loading and unloading processes are carried out. Gas forms inside the cell housing. After the formation and aging process, a heat sealing process can be carried out in which a sealing seam is created which divides the cell housing interior into a stacking chamber in which the electrode/separator stack is arranged and into a gas pocket in which the gas collects. The gas pocket can be separated from the cell housing at the end of the manufacturing process.

Two connection valves are preferably provided. A first connection valve forms an electrolyte inlet valve, while the second connection valve can be implemented as an air outlet valve through which air is sucked out of the cell housing interior in the vacuum forming process. In addition, at least one of the connection valves, in particular the air outlet valve, can enable an emergency gas outlet in the event of a thermal runaway of the battery pouch cell. The electrolyte inlet valve can be designed as a check valve that opens towards the inside of the cell housing and blocks in the opposite direction. Alternatively and/or additionally, the air outlet valve can also be a check valve that blocks in the direction of the cell housing interior and opens in the opposite direction.

During cell operation, the battery pouch cell is subject to operational expansion and contraction in the stacking direction. The reinforcing frame is designed so that it can follow such expansion or contraction. For example, the outer legs of the frame parts can be connected to one another via an articulated connection. In this case, during a stack expansion, the frame parts can tilt outwards around the joint connection. During a stacking contraction, a counter-tilting movement can occur back to the original length. In order to support the counter-tilting movement back to the starting position, an elastomer body can be supported between the outer legs of the frame parts. This can build up a restoring force through elastic deformation during the outward tilting movement. The restoring force can be reduced during the counter-tilting movement, which supports the return of the reinforcing frame towards the initial length.

An exemplary embodiment of the invention is described below with reference to the attached figures.

• 1 bis 15 unterschiedliche Ansichten, anhand derer das erfindungsgemäße Verfahren veranschaulicht ist.

Show it:

• 1 to 15 different views which illustrate the method according to the invention.

In 1 A battery pouch cell is shown in a roughly schematic view from above, the upper housing part 1 of which is omitted for reasons of clarity, so that the interior of the housing is exposed. Accordingly, the battery pouch cell has, in addition to the upper housing part 1 (not shown), a lower housing part 1, which merges into the upper housing part in the same material and in one piece at a folding edge 3. The two housing parts 1 are folded over by 180° at the folding edge 3. Their opposite housing part edges 5 are joined together by means of a sealing seam 7 to form a circumferential housing flange. An electrode/separator stack 9 is also arranged inside the cell housing. Its edge sides and its corners are covered by strips of adhesive tape 11. Furthermore, cathode-side and anode-side cell conductors 13, 15 protrude from the electrode/separator stack 9, which are guided to the outside through the circumferential housing flange.

The production of the cell housing 3 is based on the 2 to 12 described. Accordingly, initially according to the 2 or 3 an endless film material web 14 provided on a coil. The endless film material web 14 is guided into a cutting station 12 by means of a gripper 18 and there on a cutting line 16 ( 3 ) cut into a film material blank 17. The two housing parts 1 are in the film material blank 17 Cell housing 3 included, which merge into one another at the folding edge 3.

This is followed by a laying process ( 4 ), in which the electrode/separator stack 9 as well as an electrolyte inlet valve 19 and an air outlet valve 21 are placed on the film material blank 17. The electrolyte inlet valve 19 is designed as a check valve that opens towards the inside of the cell housing and blocks in the opposite direction. In the same way, the air outlet valve 21 is also a check valve. This blocks towards the inside of the cell housing and opens in the opposite direction. In the transshipment process this is done in the 4 Housing part 1 on the right is folded around the folding edge 3 by 180 ° in a folding direction U. After the folding process, a joining process starts, in particular a heat sealing process, in which the sealing seam 7 is produced, which joins the housing part edges 5 of the two housing parts 1 facing one another to form a circumferential housing flange, specifically forming the cell housing 2.

The essence of the invention is that after the above-mentioned joining process, a vacuum forming process is carried out in which the air outlet valve 21 is connected to a suction pump 23 so that air 28 ( 8th ) is sucked out of the cell housing 2. As a result, the film material of the cell housing 2 is pulled around the electrode/separator stack 9 with a negative pressure effect.

The adhesive strips 11 broken onto the electrode/separator stack 9 act as reinforcing elements, with the help of which the electrode/separator stack 9 remains dimensionally stable during the vacuum forming process, i.e. is not bent.

After the vacuum forming process, a filling process begins in which liquid electrolyte 34 is fed under pressure from an electrolyte reservoir 25 into the interior of the cell housing with the aid of a metering pump 27. The metering pump 27 is in the 8th or 9 connected to the electrolyte reservoir 25 via another check valve 30. In addition, an externally controllable two-way valve 32 is arranged in the pressure line leading from the metering pump 27 to the electrolyte inlet valve 19.

After the filling process is complete, a formation and aging process is carried out, during which gas forms inside the cell housing. Following the formation and aging process, a sealing seam 29 ( 10 ), which divides the cell housing interior into a stack chamber 31, in which the electrode/separator stack 9 is arranged, and into a gas pocket 33, in which the gas formed collects. At the end of the manufacturing process, the gas pocket 33 is cut along an indicated cutting line 35 ( 11 ) separated from the cell housing 2.

As an alternative to the embodiment variant shown, such a separation of the gas pocket 33 from the cell housing 2 can be dispensed with and instead the inlet and outlet valves 19, 21 remain on the cell housing 2. In this case, in the event of a thermal runaway of the battery pouch cell through the air outlet valve 21 Emergency gas exit can be made possible.

In the previous figures, adhesive strips 11 are applied to the electrode/separator stack 9. Instead, in the 13 and 14 the electrode/separator stack 9 is dimensionally stabilized with the aid of a circumferential reinforcing frame 37, which surrounds the edge of the electrode/separator stack 9. The reinforcing frame 37 consists of two frame parts 39, between which the electrode/separator stack 9 is arranged. Like from the 14 As can be seen, each of the frame parts 39 has an angular profile in cross section, with a clamping leg 41 which lies on a stack end of the electrode/separator stack 9, and with an outer leg 43 which delimits the electrode/separator stack 9 laterally outside. The angle profile of the frame part 39 therefore forms an inner corner area that completely surrounds the edges and corners at the end of the stack. According to the 14 the outer legs 43 of the frame parts 39 are spaced apart from the electrode/separator stack 9 by a clearance 45. In addition, the outer legs 43 of the frame parts 39 are optionally connected to one another at a connection point or an articulated connection 47. In the 14 the connection point 47 has an elastomer body 49. Passage openings 40 are formed in the clamping legs 41 of the two frame parts 39, through which the electrolyte 34 can flow up to the edge of the electrode/separator stack 9.

The electrode/separator stack 9 can be implemented as a jelly roll, which does not have individual sheets stacked one on top of the other, but is instead designed as an electrode/separator winding. In this case, the reinforcing frame 37 is arranged on each end face of the jelly roll, whereby the end edges of the electrode/separator winding are protected from deflection during vacuum forming.

Like from the 15 As can be seen, the electrode/separator stack 9 (not shown) (for example a jelly roll) is subject to an operational expansion (see arrows up and down) or a contraction in the stacking direction. During a stack expansion, a tilting movement K of the frame parts 39 takes place Articulated connection 47 to the outside. During a stacking contraction, a reverse counter-tilting movement occurs back to the starting position. With the help of the elastomer body 49 arranged in the joint connection 47, an elastic restoring force can be built up during the outward tilting movement K. This is reduced again during the counter-tilting movement (i.e. during the contraction), which supports the return towards the starting position.

In the 15 the two frame parts 39 (viewed in cross section) are connected to one another in the manner of a ball joint, with the distance between the upper and lower ball seats not being constant. There is more play in the direction of the electrode/separator stack 9, while there is less play in the opposite direction. The space between the two ball seats is partially filled with the elastomer body 49. The elastomeric body 49 is compressed during stack expansion as the ball seats rotate relative to each other. The elastically flexible elastomer body 49 builds up a restoring force by means of which the two frame parts 39 can be reset to their starting position during the stack contraction. In this way, the frame parts 39 can protect the edges and corners of the stack 9 well against mechanical damage and are also flexible to adapt to the swelling process. Another possible frame construction is to use a tension spring between the two frame parts 39, which, however, means additional weight. Another possibility is to make the two frame parts 39 from elastomeric material so that they can expand and contract.

Reference symbol list

1

Housing part

3

Folding edge

5

Housing part edges

7

Sealed seam

9

Electrode/separator stack

11

Adhesive tape strips

12

cutting station

13, 15

Cell arrester

14

Continuous film material web

16

cutting line

17

Foil material cutting

18

Grabber

19

Electrolyte inlet valve

21

Air outlet valve

23

vacuum pump

25

Electrolyte reservoir

27

Dosing pump

28

Air

29

Sealed seam

30

check valve

31

Stacking chamber

32

Two-way valve

33

Case bag

34

electrolyte

35

cutting line

37

Reinforcement frame

39

frame parts

40

Electrolyte passage

41

clamping leg

43

outer thigh

45

Release

47

connection point

49

Elastomer body

U

Direction of envelope

K

Tilting movement

Claims (10)

Method for producing a battery pouch cell with a cell housing (2) made of film material, which is made up of two housing parts (1), which merge into one another in one piece at a folding edge (3), the two housing parts (1) around the folding edge (3) are folded over and the facing housing part edges (5) are joined together, characterized by the following process steps: - Laying process in which an electrode/separator stack (9) and at least one connection valve (19, 21) are placed on a film material blank (17). , which consists of the two housing parts (1); - Wrapping process in which the film material blank (17) is wrapped around the electrode/separator stack (9); - Joining process in which the facing housing part edges (5) are joined together to form the cell housing (2); and - vacuum forming process, in which the connection valve (19, 21) is connected to a vacuum source (23), so that the cell housing (2) is pulled around the electrode/separator stack (9) using a vacuum effect. Procedure according to Claim 1 , characterized in that the electrode/separator stack (9) has at least one reinforcing element, by means of which the electrode/separator stack (9) remains dimensionally stable during the vacuum forming process, i.e. is not bent, and that the reinforcing elements are strips of adhesive tape (11), with the help of which the sides and/or the corners of the electrode/separator stack (9) are stiffened, or that the reinforcing element is a circumferential reinforcing frame (37), which consists of two frame parts (39), between which the electrode/separator stack ( 9) is arranged. Procedure according to Claim 2 , characterized in that each frame part (39) has an angle profile in cross section, with a clamping leg (41) which lies on a stack end of the electrode/separator stack (9), and with an outer leg (43) which lies laterally outside delimits the electrode/separator stack (9), so that the angle profile forms an inner corner area which surrounds the edges and corners at the end of the electrode/separator stack (9). Procedure according to Claim 3 , characterized in that the electrode/separator stack (9) is realized as an electrode/separator winding, ie jelly roll, and that the reinforcing frame (37) is arranged on each end face of the jelly roll, whereby the end edges of the electrode /Separator winding are protected from deflection during vacuum forming, and / or that the two frame parts (39) of the respective reinforcing frame (37) are connected to one another via an articulated connection (47) in such a way that they can move during expansion and contraction of the electrode / Separator stack (9) can also be pulled apart and pulled together. Method according to one of the preceding claims, characterized in that after the vacuum forming process, a filling process takes place in which liquid electrolyte (34) is fed through the connection valve (19) into the cell housing interior, and the electrolyte (34) is drawn from an electrolyte reservoir (25). is guided under pressure into the cell housing interior by means of a pump (27). Procedure according to Claim 5 , characterized in that after the filling process, a formation and aging process takes place, during which gas forms in the cell housing interior, and that after the formation and aging process, a sealing process is carried out, in which a sealing seam (29) is created, which divides the cell housing interior into a stacking chamber (31) in which the electrode/separator stack (9) is arranged, and into a gas pocket (33) in which the gas collects, and that the gas pocket (33) is removed from the cell housing (2.) at the end of the manufacturing process ) is separated. Method according to one of the preceding claims, characterized in that a first connection valve is an electrolyte inlet valve (19) and a second connection valve is an air outlet valve (21) through which air is sucked out of the cell housing interior in the vacuum forming process, and that the air -Exhaust valve (21) allows gas to escape in the event of a thermal runaway of the battery pouch cell. Procedure according to Claim 7 , characterized in that the electrolyte inlet valve (19) is a check valve that opens towards the inside of the cell housing and blocks in the opposite direction, and / or that the air outlet valve (21) is a check valve that blocks towards the inside of the cell housing and opens in the opposite direction . Procedure according to one of the Claims 4 until 8th , characterized in that the electrode/separator stack (9) is subject to operational expansion and contraction in the stacking direction, and/or that the outer legs (43) of the frame parts (39) are connected to one another via an articulated connection (47), so that During a stack expansion, a tilting movement (K) of the frame parts (39) takes place outwards around the joint connection (47), and/or during a stack contraction, a counter-tilting movement takes place back to the starting position, and that between the outer legs (43). Frame parts (39) are supported by an elastomer body (49), which builds up a restoring force during the outward tilting movement, and that the restoring force is reduced again during the counter-tilting movement, thereby supporting the return towards the starting position. Battery pouch cell produced using a method according to one of the preceding claims.

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