Cover assembly for a prismatic cell

Abstract

The invention relates to a cover assembly for a prismatic cell, comprising a metal frame which is designed to be attached to a housing of the prismatic cell. The cover assembly additionally comprises a base plate, which is made of an electrically insulating plastic and which is mounted within the metal frame and forms an interlocking or frictional connection with the metal frame, and at least one first insert part, wherein the first insert part is interlockingly secured to the base plate and is a terminal feedthrough.

Description

[0001] Cover assembly for a prismatic cell

[0002] Description

[0003] The invention relates to a cover assembly for a prismatic cell, a cover assembly arrangement, a prismatic cell and a method for producing a cover assembly.

[0004] Prismatic cells are used, for example, in rechargeable lithium-ion batteries, sodium-ion batteries, or supercapacitors. A prismatic cell comprises a housing, usually made of aluminum, and a cover assembly that is arranged on the housing. The cover assembly has the task of closing and sealing the battery housing in order to protect the cell chemistry from the environment. In addition, the cover assembly should prevent the penetration of interfering substances such as oxygen or water from the outside. Furthermore, the cover assembly should enable the connection of the electrodes inside the cell and electrical contact outside the cell. The electrical poles in the cover assembly must be electrically insulated from one another. To achieve these tasks, cover assemblies are often complex assemblies consisting of a large number of components.

[0005] It is an object of the invention to provide an improved lid assembly, an improved lid assembly arrangement, an improved prismatic cell and an improved method for producing a lid assembly with simple and cost-effective manufacturability.

[0006] This object is achieved by a cover assembly having the features of claim 1, as well as by a cover assembly arrangement having the features of claim 13, a prismatic cell having the features of claim 14 and a method for producing a cover assembly having the features of claim 15.

[0007] The subclaims show preferred developments of the invention. The cover assembly according to the invention with the features of claim 1 comprises a metallic frame which is designed to be fastened to a housing of the prismatic cell. Furthermore, the cover assembly comprises a base plate made of an electrically insulating plastic, which is arranged on the metallic frame and forms a positive, material and / or force-fitting connection with the metallic frame. The positive connection preferably has a toothing so that the mechanical strength and sealing properties of the connection are improved. The electrically insulating plastic can be a material from the group of thermoplastics, elastomers, thermosets or thermoplastic elastomers. In particular, the electrically insulating plastic is made of PPS, PPA, PBT, LCP [Liquid Crystal Polymer], EPDM or PP.The cover assembly also includes at least one first insert, which is secured to the base plate in a form-fitting, material-fitting, and / or friction-fitting manner. The first insert is an electrically conductive terminal feedthrough.

[0008] The cover assembly preferably comprises a terminal feedthrough designed as an anode and another terminal feedthrough designed as a cathode. The cathode is preferably made of aluminum and the anode is preferably made of copper, aluminum, or both metals. The structure according to the invention makes it possible to realize a cover assembly that can be manufactured simply and cost-effectively and at the same time enables reliable closure of the prismatic cell. The integration of inserts into the base plate enables simple integration of additional functionalities. Furthermore, the integrated design of the cover assembly reduces its assembly effort. A further advantage is the ability of the base plate to compensate for tolerances in the frame or inserts during production.The metallic frame creates an interface that allows for easy welding of the lid assembly to the prismatic cell, especially when the frame metal is the same as that of the cell casing. The base plate, made of electrically insulating plastic, eliminates the need for an additional internal insulation plate. This results in a significant gain in space within the cell, allowing the cell's capacity to be increased while maintaining the same external dimensions.

[0009] Preferably, the terminal bushing is a sheet metal component with a U-shaped cross-section aligned coplanar with the base plate. The U-shaped cross-section of the terminal bushing is easy to manufacture. A reliable positive connection can be created by flowing behind the U-shaped cross-section with the electrically insulating plastic of the base plate. The sides of the U-shaped cross-section of the terminal bushing that are exposed to the inside and outside enable good contact with the cover assembly. Further preferably, a tongue and groove connection, a dovetail connection, or interlocking teeth is formed between the terminal bushing and the base plate. These connections are easy to manufacture and form a reliable connection. Other designs of the terminal bushing include cut-to-length rod profiles, deep-drawn parts, forged parts, and die-cast parts.

[0010] An additional sealing element can be located between the terminal element and the base plate, sealing the interface between the terminal bushing and the base plates. This is particularly important when the cell is operating at high temperature differences; the sealing element compensates for the different thermal expansions of both materials. The sealing element can be implemented by overmolding the terminal bushing or as a separate element that is inserted and overmolded when the base plate is attached.

[0011] Preferably, the plastic of the base plate is a thermoplastic, an elastomer, a thermoset or a thermoplastic elastomer.

[0012] Furthermore, the lid assembly preferably includes a bursting zone. In the event of a cell failure, the bursting zone allows for temperature- and, in particular, pressure-activated opening, allowing the gaseous and particulate degradation products released in the event of thermal runaway to leave the prismatic cell and be discharged in a location-controlled manner. For this purpose, a defined mechanical and thermal weak point is preferably incorporated in the bursting zone. The bursting zone can be easily integrated into the lid assembly, thus reducing the manufacturing effort for the prismatic cell housing.

[0013] Preferably, the burst zone is designed as a second insert in the base plate or integrated into the base plate through a reduced wall thickness. The direct integration of the burst zone into the base plate through a reduced wall thickness enables simple and cost-effective integration without additional components or additional assembly steps. Designing the burst zone as a second insert also enables simple integration into the base plate and additional flexibility in the design of the burst zone.

[0014] In a further preferred embodiment, the cover assembly comprises a first bursting zone and a second bursting zone, wherein the compressive strength of the second bursting zone is higher than the compressive strength of the first bursting zone. The first bursting zone allows the prismatic cell to release gases when cell failure begins. These gases can be detected using appropriate sensors. This gives the operator of the prismatic cell a significantly longer time to react to the subsequent thermal runaway and propagation to adjacent cells. The second bursting zone, which preferably allows a significantly larger opening, serves to specifically release combustion gases and divert the combustion gases into an area where only minimal damage occurs and where, ideally, no propagation to other battery cells occurs.The multi-stage burst zone can be realized through a single opening with a stepped cross-section. Alternatively, the first and second burst zones can be mounted separately on the lid assembly.

[0015] The base plate preferably includes a reinforcing structure. The reinforcing structure is preferably a rib arranged adjacent to the burst area to define an outflow direction from the burst area. The rib can reinforce the base plate and the cover assembly. Furthermore, the arrangement of the rib between the terminal feedthrough and the burst area enables protection of the electrical elements—in particular, the cell connectors—from electrically conductive particles that may escape from the burst area in the event of a cell failure.

[0016] More preferably, the metallic frame is designed as a stamped part, a die-cast part, or as a formed profile. The stamped part design enables cost-effective production of the frame while maintaining high mechanical strength and eliminating any joints. Furthermore, the stamped part design enables easy integration of reinforcing webs. The formed profile design enables a metallic frame with a customized cross-section, so that, for example, a reliable form-fitting connection can be created between the metallic frame and the base plate. The die-cast part design enables production with even less waste, which can also be immediately reintroduced into the melt. In addition, stiffening elements (e.g., a honeycomb structure) can be easily incorporated. Significantly smaller corner radii can also be achieved compared to stamped and bent parts.

[0017] According to a further preferred embodiment of the invention, the base plate comprises a gas permeation-reducing coating. This can prevent the penetration or escape of gases into or from the prismatic cell through the cover assembly. The gas permeation-reducing coating is preferably applied to an outer or inner side of the cover assembly. If the cover assembly is coated internally, attention must be paid to the electrolyte resistance of the gas permeation-reducing coating. Possible designs of the gas permeation-reducing coating are coatings made of SiO2, EVOH, or metal. If the coating is made of metal, the gas permeation-reducing coating is preferably spaced at least 2 mm from the terminal feedthrough. The base plate of the cover assembly preferably has at least one filling opening. The base plate particularly preferably has two filling openings.An electrolyte can be filled into the prismatic cell through the filling opening. A second filling opening facilitates the evacuation of the gas displaced by the electrolyte, thereby accelerating the filling process. Preferably, the filling opening is designed to be closed by a plug. Particularly preferably, the plug is designed to be welded to the lid assembly after the cell has been filled.

[0018] More preferably, the filling opening is designed as a third insert. This allows the filling opening to be designed flexibly and independently of the base plate and easily integrated into the base plate. By placing the filling opening in the base plate made of an electrically insulating plastic, no contamination from electrically conductive particles can enter the cell during the final welding of the cell.

[0019] The invention further describes a cover assembly arrangement comprising a first cover assembly and a second cover assembly. The terminal feedthrough of the first cover assembly is an anode, and the terminal feedthrough of the second cover assembly is a cathode. Furthermore, the first cover assembly and the second cover assembly are configured to be attached to opposite ends of the prismatic cell. Thus, the electrical poles of the prismatic cell can be located at two opposite ends, simplifying current conduction. Furthermore, the cover assembly arrangement enables the use of, for example, extruded housing profiles, which can be easily and cost-effectively closed at the two open ends by the cover assembly arrangement.

[0020] The invention also describes a prismatic cell comprising a housing, an electrical energy storage device and a previously described cover assembly or cover assembly arrangement.

[0021] Furthermore, the invention relates to a method for producing a cover assembly for a prismatic cell. The method comprises the steps of arranging a metallic frame and a first insert, which is a terminal feedthrough, relative to one another. Subsequently, a base plate is produced by injection molding the metallic frame and the first insert using an electrically insulating plastic, so that a positive, material, and / or force-fitting connection is formed between the base plate and the metallic frame and a positive connection between the first insert and the base plate. The electrically insulating plastic is preferably a thermoplastic or an elastomer.Further preferably, in the method for producing the lid assembly, a second insert, which comprises a bursting area, and / or a third insert, which comprises a filling opening, are connected to the base plate during the injection molding process. Thus, all insert components can be integrated into the lid assembly in a single injection molding process, eliminating complex assembly steps.

[0022] Particularly preferred in the process for manufacturing the cover assembly is to incorporate the bursting area integrally into the base plate through the injection molding process. By directly integrating the bursting area into the base plate during the injection molding process, an additional component can be eliminated.

[0023] Particularly preferred is a method for producing the lid assembly in which the filling opening is also integrally incorporated into the base plate.

[0024] Further details, advantages, and features of the present invention will become apparent from the following description of exemplary embodiments with reference to the drawings. It shows:

[0025] Fig. 1 is a schematic sectional view of a prismatic cell with a

[0026] Cover assembly according to a first embodiment,

[0027] Fig. 2 is a schematic plan view of the cover assembly after the first

[0028] Example,

[0029] Fig. 3 is a schematic detailed view of the cover assembly after the first

[0030] Embodiment in the transition area to a housing of the prismatic cell,

[0031] Fig. 4 a - f schematic representations of further alternatives of a connection between a first insert and a base plate, and

[0032] Fig. 5 is a schematic representation of a prismatic cell with a first

[0033] Cover assembly and a second cover assembly, according to a second embodiment.

[0034] A cover assembly 1 and a method for producing the cover assembly 1 according to a first embodiment of the invention are described in detail below with reference to Figures 1 to 3.

[0035] Figure 1 shows a sectional view through a longitudinal plane of a prismatic cell 3. The prismatic cell 3 comprises a housing 2, which is closed on one upper side by the cover assembly 1. An electrical energy storage device 4 is arranged within the housing 2. The electrical energy storage device 4 comprises at least one negative electrode 7 and one positive electrode 8, which are enclosed by an electrolyte 9. The electrical energy storage device 4 can be, for example, a lithium-ion battery, a sodium-ion battery, or a supercapacitor.

[0036] The cover assembly 1 in Figure 1 comprises a metallic frame 11, which is attached to the housing 2 of the prismatic cell 3 by a welded joint 27. The housing 2 preferably has a wall thickness of 0.3 - 1.0 mm and is made of aluminum.

[0037] A base plate 12 made of an electrically insulating plastic is arranged within the metallic frame 11. A positive connection is formed between the base plate 12 and the metallic frame 11.

[0038] The cover assembly 1 comprises two terminal feedthroughs 21, two filling openings 24, and a bursting area 22 with a first bursting area 22a and a second bursting area 22b. The two terminal feedthroughs 21 are designed as a first insert 31, the two filling openings 24 as a third insert 33, and the bursting area 22 as a second insert 32, which are overmolded by the electrically insulating plastic of the base plate 12. The outer contour of the inserts 31, 32, 33 enables the formation of positive connections between the base plate 12 and the inserts 31, 32, 33.

[0039] The terminal bushings 21 have a U-shaped cross-section, with the electrically insulating plastic of the base plate 12 flowing between the two legs of the U-shaped cross-section to form a positive connection. The U-shaped cross-section is aligned coplanar to the base plate 12. An outer side of the U-shaped cross-section of the terminal bushing 21 is directed towards the interior of the prismatic cell 3. One terminal bushing 21 is connected to the negative electrode 7, thus forming an anode 25, and another terminal bushing 21 is connected to a positive electrode 8, thus forming a cathode 26. The other outer side of the U-shaped cross-section of the terminal bushing 21 is directed outwards and is designed to be contacted with an electrical conductor.

[0040] The terminal bushings 21 are arranged in the longitudinal direction R1 at two lateral ends near the metallic frame 11. The distance to the metallic frame 11 must be large enough to prevent voltage breakdown from the terminal bushing 21 to the housing.

[0041] The bursting area 22 is located centrally in the lid assembly 1. The bursting area 22 has a stepped structure, forming a first bursting area 22a and a second bursting area 22b. The first bursting area 22a has a smaller thickness than the second bursting area 22b. Thus, the compressive strength of the first bursting area 22a is lower than the compressive strength of the second bursting area 22b, so that in the event of cell failure, the first bursting area 22a opens first to relieve increasing pressure from the interior of the prismatic cell. The second bursting area 22b can then open if the pressure inside the prismatic cell continues to rise. The first bursting region 22a is arranged within the second bursting region 22b, wherein a notch is formed between the first bursting region 22a and the second bursting region 22b, which notch forms a defined failure point.A notch is also formed on the outer circumference of the second bursting area 22b, which forms a defined failure point for the second bursting area 22b.

[0042] Between the bursting area 22 and the pole bushings 21, a rib 13 is formed, which is part of the base plate 12 and is aligned perpendicular to it and defines an outflow direction from the bursting area 22.

[0043] The filling opening 24 is arranged in the base plate 12 between the two ribs 13 and the two terminal feedthroughs 21. One filling opening 24 is used to introduce the electrolyte 9 into the prismatic cell 3, and the other filling opening 24 is used to expel the gas displaced by the electrolyte 9. For this purpose, the filling openings 24 have a cylindrical through-hole, which is designed to be closed by a plug.

[0044] On an outer side of the base plate 12 of the cover assembly 1, which is oriented perpendicular to the transverse direction R2, a gas permeation-reducing coating 23 is applied, which prevents a gas exchange between the electrical energy storage device 4 and the environment outside the prismatic cell 3 when the prismatic cell 3 is filled.

[0045] The cover assembly 1 according to the first embodiment is manufactured using an injection molding process. For this purpose, in a first step, the metallic frame 11, the first insert 31, the second insert 32, and the third insert 33 are inserted into a mold of an injection molding tool, aligned, and fixed. Finally, an electrically insulating plastic is introduced into the mold, wherein the plastic comes into contact with the metallic frame 11 and the inserts 31, 32, 33 and hardens. The hardened plastic forms the base plate, which is connected to the metallic frame 11 and the inserts 32, 32, 33 by a positive and / or non-positive connection.

[0046] Figure 2 shows a plan view of the lid assembly 1 of the prismatic cell 3 from Figure 1. The metallic frame 11 has a rectangular shape and forms the outer edge of the lid assembly 1. The base plate 12, on which the gas permeation-reducing coating 23 is applied, is arranged within the frame.

[0047] The terminal feedthroughs 21, filling openings 24, and the bursting area 22 are distributed centrally along a longitudinal axis XX. The inserts 31, 32, 33 are spaced apart from the metallic frame 11. The bursting area 22 has an oval shape in plan view.

[0048] The ribs 13 extend from one side of the metallic frame 11 to an opposite side of the metallic frame 11. The ribs 13 are aligned perpendicular to the longitudinal axis XX.

[0049] Figure 3 shows a detailed view of the prismatic cell 3 from Figure 1 in the transition area between the cover assembly 1 and the housing 2.

[0050] In the first embodiment shown in Figure 3, the metallic frame 11 is designed as a formed profile. A portion of the metallic frame 11 is arranged in the base plate 12.

[0051] The formed profile of the metallic frame 11 has three bends in its cross-section, resulting in an undercut 11a. The undercut 11a forms a positive connection between the metallic frame 11 and the base plate 12 in the longitudinal direction R1 and the transverse direction R2, resulting in a stable connection with high sealing properties. Furthermore, the formed profile of the metallic frame 11 forms an upper and lateral stop, which is configured to contact the housing 2.

[0052] The outer end of the metallic frame 11, which is not located in the base plate 12, is integrally connected to the housing 2 of the prismatic cell 3 by a welded joint 27. Thus, the housing 2 and the cover assembly form a closed unit, preventing the electrolyte 9 from escaping.

[0053] Figures 4 a - f show different alternatives for the connection between the first insert part 31 and the base plate 12. The connection between the base plate 12 and the second insert part 32 and / or the third insert part 33 can be the same or different.

[0054] Figure 4 a shows a connection in which the first insert 31 has a pin at the center of its lateral end. During the manufacturing process, the electrically insulating plastic of the base plate 12 flows around the pin, whereby the base plate has a U-shaped cross-section in the connection area, with the pin arranged in the center of said cross-section, such that a positive connection is present in the transverse direction R2. Figure 4 b shows a further alternative connection in which the first insert 31 has a groove at the center of its lateral end. During the manufacturing process, the electrically insulating plastic of the base plate 12 flows into the groove, creating a positive connection between the insert and the base plate 12 in the transverse direction R2.

[0055] Figure 4c shows another alternative connection between the first insert 31 and the base plate 12, in the form of a dovetail joint. The first insert 31 has a dovetail-shaped groove into which the plastic of the base plate flows during the manufacturing process to form a positive connection in the transverse direction R2 and the longitudinal direction R1.

[0056] Figure 4d shows another alternative connection between the first insert part 31 and the base plate 12. The first insert part 31 has a step at one end in the longitudinal direction R1. The base plate 12 forms an opposite step, creating a positive connection in the direction of the cover assembly.

[0057] Figure 4 e shows a further alternative of a step-shaped connection between the first insert part 31 and the base plate 12. The step has an undercut 11a in the longitudinal direction R1, so that the connection is additionally positive-locking in the longitudinal direction R1.

[0058] Figure 4 f shows another alternative for a connection between the first insert 31 and the base plate 12. The first insert 31 has a groove at an outer end in the longitudinal direction R1. The flanks of the groove, which are oriented perpendicular to the transverse direction R2, have a toothed surface, so that the connection, in comparison to the connection in Figure 4 b, additionally forms a positive connection with the base plate in the longitudinal direction R1.

[0059] Figure 5 shows a second embodiment of the prismatic cell 3 with the housing 2 and a cover assembly arrangement 14 connected thereto, comprising a first cover assembly 5 and a second cover assembly 6.

[0060] The first cover assembly 5 is attached to a first end of the housing 2 in the transverse direction R2. The second cover assembly 6 is attached to a second end of the housing 2 in the transverse direction R2. The first cover assembly 5 and the second cover assembly 6 are arranged parallel to each other.

[0061] The first cover assembly 5 and the second cover assembly 6 both have a stamped metallic frame 11, which is connected to the housing 2 of the prismatic cell 3 via a welded joint 27. The metallic frame 11 is connected to the base plate 12 in a force-fitting manner and in the longitudinal direction R1 in a form-fitting manner.

[0062] The first cover assembly 5 has a filling opening 24 and a bursting area 22, which are directly integrated into the base plate 12 due to its shape. The bursting area 22 is configured as shown in Figure 1 and has a first bursting area 22a, which is located within the second bursting area 22b. The first bursting area 22a has a lower compressive strength and temperature resistance than the second bursting area 22b.

[0063] Furthermore, the first cover assembly 5 has a terminal feedthrough 21, which is connected to the negative electrode 7 in the interior of the prismatic cell 3, so that the terminal feedthrough 21 of the first cover assembly 5 forms an anode 25. The anode 25 is preferably made of copper in lithium-ion batteries and of aluminum in sodium-ion batteries.

[0064] The second cover assembly 6 has a filling opening 24 and a terminal feedthrough 21. The filling opening 24 is integrated into the base plate 12 due to its shape. The terminal feedthrough 21 is designed as a first insert 31 and is connected to the positive electrode 8 inside the prismatic cell 3. Thus, the terminal feedthrough 21 of the second cover assembly 6 forms a cathode 26.

[0065] The pole bushings 21 of the first and second cover assemblies 5, 6 are positively connected to the base plate 12 with a dovetail-shaped connection in the longitudinal direction R1 and transverse direction R2.

[0066] The filling opening 24 of the first cover assembly 5 is arranged at a first end in the longitudinal direction R1. The filling opening 24 of the second cover assembly 5 is arranged at a second end in the longitudinal direction R1. Thus, when the prismatic cell 3 is geodetically aligned with the longitudinal direction R1 facing upwards, the electrolyte 9 can be introduced from below into the interior of the prismatic cell 3 via the filling opening 24 in the first cover assembly 5, while the displaced gas can escape through the filling opening 24 in the second cover assembly 6.

[0067] In addition to the above written description of the invention, reference is hereby explicitly made to the graphic representation of the invention in the figures for its supplementary disclosure.

Claims

Patent claims 1. Cover assembly for a prismatic cell (3), comprising . a metallic frame (11) adapted to be fixed to a housing (2) of the prismatic cell (3), . a base plate (12) made of an electrically insulating plastic, which is arranged on the metallic frame (11) and forms a positive and / or material-locking and / or force-locking connection with the metallic frame (11), and . at least one first insert part (31), wherein the first insert part (31) is positively secured to the base plate (12), . wherein the first insert (31) is a pole bushing (21).

2. Cover assembly according to claim 1, wherein the pole bushing (21) is a sheet metal component with a U-shaped cross-section which is aligned coplanar to the base plate (12).

3. Cover assembly according to claim 1, wherein a tongue and groove connection, a dovetail connection or an intermeshing toothing is formed between the pole feedthrough (21) and the base plate (12).

4. Cover assembly according to one of the preceding claims, wherein the plastic of the base plate (12) is a thermoplastic, an elastomer, a thermoset or a thermoplastic elastomer.

5. Lid assembly according to one of the preceding claims, wherein the lid assembly (1) comprises a burst area (22).

6. Lid assembly according to claim 5, wherein the bursting region (22) is designed as a second insert (32) in the base plate (12) or wherein the bursting region (22) is integrated into the base plate (12) by a reduced wall thickness.

7. Lid assembly according to claim 5 or 6, wherein the lid assembly (1) comprises a first bursting region (22a) and a second bursting region (22b), wherein the compressive strength of the second bursting region (22b) is higher than the compressive strength of the first bursting region (22a).

8. Lid assembly according to one of claims 5 to 7, wherein the base plate (12) comprises a reinforcing structure, in particular a rib (13), which is arranged adjacent to the bursting area (22) in order to define an outflow direction from the bursting area (22).

9. Cover assembly according to one of the preceding claims, wherein the metallic frame (11) is formed as a stamped part, as a cast part or as a formed profile.

10. Lid assembly according to one of the preceding claims, wherein the base plate (12) comprises a gas permeation reducing coating (23).

11. Lid assembly according to one of the preceding claims, wherein the base plate (12) has at least one filling opening (24).

12. Lid assembly according to claim 11, wherein the filling opening (24) is designed as a third insert (33) in the base plate (12).

13. A cover assembly arrangement (14) comprising a first cover assembly (5) according to any one of the preceding claims, wherein the terminal feedthrough (21) of the first cover assembly (5) is an anode (25) and a second cover assembly (6) according to any one of the preceding claims, wherein the terminal feedthrough (21) of the second cover assembly (6) is a cathode (26), and wherein the first cover assembly (5) and the second cover assembly (6) are adapted to be attached to opposite ends of the prismatic cell (3).

14. Prismatic cell (3) comprising a housing (2), an electrical energy storage device (4) and a cover assembly (1) according to one of claims 1 to 12 or a cover assembly arrangement (14) according to claim 13.

15. A method for producing a cover assembly (1) for a prismatic cell (3), comprising the steps: - arranging a metallic frame (11) and a first insert (31), which is a pole feedthrough (21), and - Producing a base plate (12) by an injection molding process on the metallic frame (11) and the first insert part (31) with an electrically insulating plastic, so that a positive, material and / or force-fitting connection is formed between the base plate (12) and the metallic frame (11) and a positive connection between the first insert part (31) and the base plate (12).

16. A method for producing a lid assembly (1) according to claim 15, wherein a second insert (32) comprising a burst region (22) and / or a third insert (33) comprising a filling opening (24) are connected to the base plate (12) during the injection molding process.

17. A method for producing a lid assembly (1) according to claim 15 or 16, wherein the burst region (22) is integrally incorporated into the base plate (12) during the injection molding process.

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