Method for mounting a sealing element on a sealing area of ​​a battery housing

Abstract

A method for mounting a sealing element (12) on a sealing area (16) of a battery housing (14) is described, wherein the method comprises at least the following process steps: i) Providing a battery housing (14) having a sealing area (16); ii) Arranging the sealing element (12) on the sealing area (16); and iii) Introducing a filling medium (22) into the battery housing, wherein the sealing element (12) is swellable by the filling medium (22). The method further comprises the following process step: iv) Applying a swelling medium (24) to the sealing area (16) or to the sealing element (12) to pre-swell the sealing element (12), wherein process step iv) is carried out before process step iii), the introduction of the filling medium (22) can be made possible without or with reduced leakage of the filling medium.

Description

[0001] The invention relates to a method for mounting a sealing element on a sealing area of ​​a battery housing. The invention further relates to a semi-finished product for producing a battery housing provided with a sealing element.

[0002] In battery manufacturing, it is often necessary to attach sealing elements to the battery casing to seal the interior. This can be particularly important when direct cooling using a fluid coolant is used, allowing battery components located inside the casing to be cooled.

[0003] DE 10 2022 000 147 A1 relates to an electrical energy storage device for a motor vehicle, comprising a housing in which at least one cell block with several storage cells for storing electrical energy is arranged. Direct cooling is provided, which includes at least one coolant path through which a liquid, dielectric coolant flows directly to and around at least a respective portion of the storage cells for cooling, and at least one swelling seal held to the housing and directly delimiting at least a portion of the coolant path, which is formed from a material that swells upon contact with the coolant.

[0004] There is a constant need to improve the assembly of a battery housing equipped with a seal.

[0005] The object of the present invention is to demonstrate measures that enable the safe and reliable assembly of a battery housing equipped with a sealing element.

[0006] The problem is solved according to the invention by a method with the features of claim 1 and a semi-finished product with the features of claim 9. Preferred embodiments of the invention are specified in the dependent claims and the following description, each of which can individually or in combination represent an aspect of the invention.

[0007] One aspect of the invention relates to a method for mounting a sealing element on a sealing area of ​​a battery housing, wherein the method comprises at least the following process steps: i) Providing a battery housing having a sealing area; ii) Arranging the sealing element on the sealing area; and iii) Introducing a filling medium into the battery housing, wherein the sealing element is swellable by the filling medium.

[0008] The process is characterized by the fact that it includes the following additional process step: iv) Applying a swelling medium to the sealing area or to the sealing element to pre-swell the sealing element, wherein process step iv) is carried out before process step iii).

[0009] Such a method offers significant advantages over prior art solutions, particularly with regard to the mounting of the sealing element on the battery housing.

[0010] The method described here is used to mount a sealing element to a sealing area of ​​a battery housing. For the purposes of this invention, the sealing area is understood to be the area against which the sealing element rests during operation of the battery housing, or after the sealing element has been mounted. A sealing element is particularly advantageous when an internal volume of the battery housing needs to be sealed to the outside. For example, a seal is necessary when direct cooling is used. Direct cooling means that components located within the battery housing, such as battery cells, are directly exposed to or surrounded by a fluid cooling medium to enable particularly effective cooling.

[0011] The method for mounting the sealing element to the battery housing comprises at least the following process steps, which do not necessarily have to be carried out in the order listed below.

[0012] According to process step i), the method described here comprises providing a battery housing with a sealing area. Such a battery housing is known per se and preferably encloses at least one battery cell or is designed to do so. For example, the battery housing can be part of a lithium-ion battery, such as that of an electric vehicle, and thus part of a high-voltage battery. The battery housing can, for example, be made of a metal and have appropriate insulating coatings. Furthermore, the battery housing expediently has a sealing area inside or on an inner surface, i.e., an area where a sealing element is to bear. This sealing area can, in principle, be designed in a known manner. This allows the interior of the battery housing to be sealed against the external environment, for example, in the case of direct cooling.

[0013] According to process step ii), the process comprises arranging the sealing element on the sealing area. This can be done in a manner known per se using conventional handling devices if the sealing element is prefabricated before being positioned on the sealing area. Alternatively, the sealing element can be directly injection-molded onto the sealing area. Regarding the material of the sealing element, conventional materials, particularly swellable ones, can generally be used. Common materials include, for example, rubber materials. The sealing element can also be formed from a swellable elastomer material.

[0014] According to process step iii), the method further comprises introducing a filling medium into the battery housing, wherein the sealing element is swellable by the filling medium. As indicated above, the filling medium can in particular be a cooling medium, which can serve to cool battery cells to be arranged in the battery housing. Accordingly, the filling medium can in particular be or comprise an organic liquid. For the purposes of the present invention, the sealing element is swellable by the filling medium, thus constituting, in other words, a swelling seal. This ensures that the sealing element swells upon contact with the filling medium, thereby enabling particularly effective sealing properties. Accordingly, the risk of leakage during battery operation can be significantly reduced.

[0015] According to the invention, it is further provided that, according to process step iv), a swelling medium is applied to the sealing area or to the sealing element to pre-swell the sealing element, wherein process step iv) takes place before process step iii). In other words, the swelling of the sealing element does not occur in a single step after the introduction of the filling medium, but rather the swelling of the sealing element takes place in multiple steps, in particular in two steps. Pre-swelling or partial swelling of the sealing element occurs before the introduction of the filling medium. In particular, such pre-swelling before the introduction of the filling medium can significantly improve a method for mounting the sealing element on the battery housing compared to prior art solutions.

[0016] The method described here allows a sealing element, which achieves its sealing effect through swelling by the medium being sealed, to swell more quickly. In particular, it enables the sealing element to be partially swollen before the battery housing is filled with the filling medium. This prevents, or at least significantly reduces, the risk of the filling medium flowing along the sealing element due to its not yet fully developed sealing properties and thus leaking out of the battery housing.

[0017] Preferably, the sealing element can achieve a complete seal at atmospheric pressure after partial swelling. Complete swelling by the filling medium further improves the seal, ensuring effective sealing even at high internal pressures. Since elevated internal pressure typically only occurs during battery operation, or at least not immediately during filling, leakage of the filling medium can be preferably prevented entirely.

[0018] This can accelerate the assembly process. Furthermore, occupational safety can be significantly improved, as the risk of contact with the filling medium can be significantly reduced.

[0019] Finally, according to the invention, the consumption of the filling medium during filling into the battery housing can be reduced, since escaping filling medium can be prevented or at least reduced.

[0020] The swelling agent can first be applied to the sealing area before the sealing element is positioned there. This can be advantageous, for example, if the sealing element is injection-molded onto the sealing area. However, it is also possible to apply the swelling agent to the sealing area or the sealing element itself when a pre-fabricated gasket is being used. Therefore, it can generally be advantageous if process step iv) is performed before process step ii). In particular, applying the swelling agent to the sealing element before process step ii) allows the sealing element to be coated as completely and comprehensively as possible with the swelling agent, which can improve pre-swelling.

[0021] Alternatively, it is also possible, and may be preferred, to perform process step iv) after process step ii). This can also be done regardless of whether the seal is prefabricated or injection-molded directly onto the sealing area.

[0022] Preferably, the swelling medium can comprise a cooling medium for battery cooling. In this embodiment, no additional material needs to be used as a swelling agent when assembling the seal to the battery housing; the assembly can be carried out using only the materials already in use. This simplifies the process. Because, as described above, little or no filling medium escapes during the filling of the battery housing, the additional swelling medium used for pre-swelling can, for example, correspond to the amount of filling medium saved due to the lack of escape. It is evident from this that the process described here is preferably possible without the use of any additional materials. Furthermore, the safety requirements for the assembly can be satisfied by existing requirements, since a cooling medium is used anyway.Accordingly, as described above, it is advantageous if the source medium corresponds to the filling medium and preferably includes the same coolant for battery cooling.

[0023] It may be further preferred that the sealing element is made of an organo-swellable elastomer, in particular organo-swellable rubber. For the purposes of the invention, an organo-swellable elastomer or rubber is understood to be one that swells under the influence of organic substances, in particular organic solvents. This embodiment allows for the particularly advantageous use of organic swelling agents. These generally do not pose a risk of negatively affecting the housing or components located therein, such as causing corrosion. Furthermore, battery cooling coolants usually contain organic solvents, so that, particularly in this embodiment, the use of coolant as a filling medium and / or swelling agent can be preferably implemented.

[0024] However, the scope of the present invention also includes the use of a water-swellable sealing element as the sealing element.

[0025] Particularly preferred materials for the sealing elements include nonpolar and saturated rubber materials, as these generally exhibit good swelling properties, especially in organic swelling media, which are suitable for the invention described herein. EPDM (ethylene propylene diene monomer rubber) is a particularly preferred material for a sealing element. However, silicone rubber, for example, can also be used.

[0026] Particularly when choosing organic source media, those that are low-viscosity and therefore exhibit fluid behavior may be preferred. However, it may also be preferable to use higher-viscosity materials, such as assembly greases or lubricating greases, which are known per se.

[0027] To enable rapid pre-swelling, hydrocarbons that are short-chain and / or have a low number of carbon atoms in their molecular structure can be used as a swelling medium. For example, it may be preferable for the swelling medium to consist of hydrocarbons with fewer than 15 carbon atoms per molecule, such as those with fewer than 10 carbon atoms per molecule, or hydrocarbons with 4 to 10 carbon atoms per molecule.

[0028] Suitable organic saturation media generally include alkanes, alkenes, cycloalkanes, and aromatic hydrocarbons. Mineral oils are preferred, but gasoline can also be used.

[0029] Regarding further advantages and technical features of the process, reference is made to the description of the semi-finished product, the figures and the description of the figures.

[0030] Another aspect of the invention is a semi-finished product for producing a battery housing provided with a sealing element, wherein the semi-finished product has a battery housing having a sealing area, wherein a sealing element provided with a swelling medium is arranged at the sealing area, and wherein the housing is optionally free of the filling medium except for the sealing area.

[0031] The semi-finished product is thus an assembly that is produced and used to equip a battery housing with a sealing element, whereby the sealing element is intended to seal the interior of the battery housing from the outside. As described in detail above, this can be advantageous when direct cooling is used to cool battery components located inside the battery housing.

[0032] A key feature of the semi-finished product is that the sealing element is positioned at the sealing area and is provided with a swelling medium. This can be achieved, as described in the process, by applying the swelling medium to the sealing area or directly to the sealing element. In this state, however, the battery housing is not yet filled with the filling medium; rather, the housing is, with the exception of the sealing area, free of the filling medium. If the swelling medium does not correspond to the filling medium, the battery housing in the semi-finished product is completely free of filling medium. However, swelling medium may be present directly at the sealing area, for example, because the swelling medium has been applied to it, or due to contact between the sealing area or the battery housing and the sealing element containing the swelling medium.

[0033] In this state, the sealing element preferably exhibits a partially swollen state, but is still capable of further swelling.

[0034] The advantage of the semi-finished product can be seen in the fact that when a filling medium, such as a coolant, is poured in, the sealing element already has a good sealing effect, thus preventing or at least significantly reducing the leakage of the filling medium at the sealing element.

[0035] Regarding further advantages and technical features of the semi-finished product, reference is made to the description of the process, the figures and the description of the figures.

[0036] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination. The drawings show: Fig. 1: a schematic sectional view of a semi-finished product for producing a battery housing equipped with a sealing element; and Fig. 2: A schematic sectional view of a battery housing equipped with a sealing element.

[0037] In the Fig. Figure 1 shows a semi-finished product 10 for producing a battery housing 14 equipped with a sealing element 12. The battery housing 14 need not yet be fully formed, but is nevertheless referred to as a battery housing 14. The battery housing 14 has a sealing area 16 for arranging the sealing element 12. The sealing element 12 is swellable and can, for example, be made of EPDM or silicone rubber. The sealing element 12 is intended to seal an interior space 18 of the battery housing 14 against the external environment, and in particular against an opening 20 of the battery housing 14. This is intended to prevent the filling medium 22, such as cooling medium, present in the interior space 18 of the battery housing 14 from escaping to the outside.

[0038] At the in Fig. In the semi-finished product 10 shown, the sealing element 12 is in a partially swollen state. Furthermore, the battery housing 14 is free of the filling medium 22; thus, no filling medium 22 has yet been introduced.

[0039] The partial swelling of the sealing element 12 is caused by a swelling medium 24. This can be, in particular, a liquid organic compound and can include, for example, the filling medium 22, such as a cooling medium. However, the swelling medium 24 can also be, for example, an assembly grease. In principle, the swelling medium 24 can be applied to the sealing element 12 and / or the sealing area 16 so that, upon contact of the sealing element 12 with the swelling medium 24, it partially swells. This creates a fast and effective seal. In this state, the filling medium 22, such as the subsequent cooling medium, can then be added, and there is no leakage at ambient pressure. This condition is brought about very quickly by the swelling medium 24.

[0040] The battery housing 14 can then be filled with the filling medium 22, bringing the sealing element 12 into contact with the filling medium 22. The battery can now be stored, shipped, or further installed. During this time, the sealing element 12 has sufficient time to swell completely due to the filling medium 22. This is in the Fig. 2 shown. In this state, the sealing element 12 now seals at the designed internal pressure and, for example, an "End of Line Test" can be performed.

[0041] However, according to the invention, it is prevented that the filling medium 22 can escape along the sealing element 12 when it is filled, or this effect is at least significantly reduced. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 000 147 A1

[0003]

Claims

[1] Method for mounting a sealing element (12) on a sealing area (16) of a battery housing (14), the method comprising at least the following method steps: i) providing a battery housing (14) having a sealing area (16); ii) arranging the sealing element (12) on the sealing area (16); and iii) introducing a filling medium (22) into the battery housing, wherein the sealing element (12) can be swelled by the filling medium (22), the method comprising the further method step: iv) applying a swelling medium (24) to the sealing region (16) or to the sealing element (12) to pre-swell the sealing element (12), wherein process step iv) takes place before process step iii). [2] The method according to claim 1, wherein step iv) is carried out before step ii). [3] A method according to claim 1, wherein step iv) is carried out after step ii). [4] Method according to one of claims 1 to 3, wherein the source medium (24) comprises a cooling medium for battery cooling. [5] Method according to one of claims 1 to 4, wherein the filling medium (22) comprises a cooling medium for battery cooling. [6] Method according to one of claims 1 to 5, wherein the source medium (24) and the filling medium (22) are identical. [7] Method according to one of claims 1 to 6, wherein the sealing element (12) is formed from an organo-swellable elastomer and the swelling medium (24) comprises a hydrocarbon compound. [8] Method according to claim 7, wherein the sealing element (12) comprises EPDM or a silicone rubber. [9] Semi-finished product (10) for producing a battery housing (14) provided with a sealing element (12), wherein the semi-finished product (10) has a battery housing (14) having a sealing region (16), wherein a sealing element (12) provided with a swelling medium (24) is arranged on the sealing region (16), and wherein the battery housing (14), optionally with the exception of the sealing region (16), is free of the filling medium (22). [10] Semi-finished product (10) according to claim 8, wherein the sealing element (12) has a partially swollen state.

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