Battery housing and vehicle battery

Abstract

The invention relates to a battery housing (1) for receiving a plurality of battery cells to form a vehicle battery, comprising at least one housing wall (2) defining a housing interior, with a gas venting opening (4) for releasing gases from the housing interior, wherein the gas venting opening (4) is closed by an adhesive film (6) glued to the housing wall (2), and a mandrel element (8) is provided for perforating the adhesive film (6) in the event of an overpressure arising during thermal runaway of a battery cell.

Description

[0001] Battery housing and vehicle battery

[0002] Technical area

[0003] The present invention relates to a battery housing for accommodating a plurality of battery cells to form a vehicle battery and a vehicle battery.

[0004] State of the art

[0005] In order to prevent an overpressure occurring, for example, due to thermal runaway of one or more battery cells inside a battery housing from leading to an uncontrolled bursting of the battery housing, it is known to provide so-called metal bursting discs on the housing, which represent a predetermined breaking point in the housing.

[0006] Instead of metal rupture discs, it is known to attach a degassing device to an opening in the housing. Degassing devices are constructed in several parts. They comprise a frame or structural body that is attached to a housing wall. Additional components are mounted in and on the frame. When overpressure occurs, these components cause a membrane element of the degassing device, which is closed under normal operating pressures in the battery, to open at a predetermined overpressure.

[0007] Such multi-part degassing devices, which are attached to the battery housing as a separate subassembly, are known, inter alia, from DE 102020 134 548 A1, DE 10 2021 106 903 A1, DE 102021 123 031 A1 or DE 102019 218 456 A1.

[0008] Description of the invention

[0009] Based on the known prior art, it is an object of the present invention to provide an improved battery housing for accommodating a plurality of battery cells to form a vehicle battery, as well as an improved vehicle battery. This object is achieved by a battery housing for accommodating a plurality of battery cells to form a vehicle battery, having the features of claim 1. Advantageous further developments emerge from the subclaims, the description, and the figures.

[0010] Accordingly, a battery housing for accommodating a plurality of battery cells to form a vehicle battery is proposed, comprising at least one housing wall defining a housing interior with a venting opening for discharging gases from the housing interior.

[0011] According to the invention, the venting opening is closed by an adhesive film bonded to the housing wall and a mandrel element is provided for perforating the adhesive film in the event of overpressure occurring during thermal runaway of a battery cell.

[0012] By using the adhesive film to close the vent opening instead of a multi-part venting device, a secure seal and reliable function can be easily achieved. Furthermore, the tolerance requirements regarding the placement of the adhesive film are comparatively low. The described solution is therefore particularly cost-effective, as the only costs incurred are essentially those for the adhesive film and the formation of the mandrel element. Installation is comparatively quick and easy.

[0013] The adhesive film is thus directly bonded to the housing wall, or rather, directly bonded to it, eliminating the need for additional components and ensuring a secure closure of the vent. The adhesive film reliably seals the vent due to its bonding to the housing wall. Therefore, no additional parts are required to close the vent, nor are any other parts involved other than the adhesive film.

[0014] The mandrel element can be arranged in the area of ​​the degassing opening in such a way that it perforates the adhesive film when the adhesive film is deformed when the overpressure occurs, which corresponds to a pressure of a predetermined level.

[0015] The perforation allows gas to be exchanged from the interior of the battery casing to the environment. The perforation can optionally function as a predetermined breaking point, whereby the pressure exerted on the adhesive film in the area of ​​the venting opening due to the excess pressure inside the battery casing can enlarge the perforation in the adhesive film. In other words, the perforation can cause the adhesive film to burst or tear, creating an opening in the adhesive film that is significantly larger than the perforation itself.

[0016] The mandrel element can be arranged on a cross strut extending transversely to the housing wall on a side of the housing wall opposite the housing interior. The mandrel element can be formed, in particular, by a cutout made in the cross strut. The cross strut can optionally extend on the side of the housing wall opposite the housing interior. In other words, the cross strut can have a base on the housing wall or be connected to the housing wall, for example, in one piece.

[0017] The mandrel element can be formed integrally with the housing wall.

[0018] The mandrel element can be positioned immovably opposite the vent opening. In other words, no moving mechanical components are required to open the vent opening when overpressure occurs. Rather, it is a simple-to-manufacture and robust system that functions virtually passively.

[0019] A tip of the mandrel element can be positioned at a predetermined distance from the plane of the adhesive film defined by the vent opening in the depressurized state. Since the adhesive film bulges outward to a greater or lesser extent in the area of ​​the vent opening, essentially depending on the pressure present inside the battery housing, by specifying a suitable distance for the tip of the mandrel element, the adhesive film can be perforated at a predetermined pressure.

[0020] The adhesive film can be glued to the inside of the housing wall facing the inside of the housing...

[0021] The mandrel element can be arranged on a side of the housing wall opposite the housing interior.

[0022] The mandrel element can be arranged such that it comes into contact with the adhesive film when the overpressure inside the housing reaches a predetermined value.

[0023] The adhesive film can be designed such that it deforms, for example, elastically and / or plastically, in the direction of the mandrel element due to an overpressure present in the housing interior. The battery housing can comprise a profile structure, for example a die-cast profile structure, optionally an extruded profile structure, wherein the housing wall and the mandrel element, and optionally additionally the cross strut, are formed in the profile structure.

[0024] The housing wall can be formed integrally with the mandrel element. Optionally, the housing wall, the cross brace, and the mandrel element can be formed integrally.

[0025] For example, the housing wall and the cross strut can be formed in the one-piece profile structure, and the mandrel element can be formed integrally on the cross strut.

[0026] The above-mentioned object is further achieved by a vehicle battery having the features of claim 10. Advantageous further developments emerge from the present description and the figures.

[0027] Accordingly, a vehicle battery is proposed, comprising a plurality of battery cells and a battery housing enclosing the plurality of battery cells according to one of the preceding embodiments.

[0028] The advantages and effects described for the battery housing can be achieved in a similar way with the vehicle battery. What is described for the battery housing also applies to the vehicle battery. Therefore, a repeated description will be omitted here to avoid redundancies.

[0029] Short description of the characters

[0030] Further embodiments of the invention are explained in more detail in the following description of the figures. In the figures:

[0031] Figure 1 schematically shows a perspective side view of a partial area of ​​a battery housing;

[0032] Figure 2 schematically shows a further perspective side view of the partial area of ​​the battery housing from Figure 1; and

[0033] Figure 3 shows a schematic sectional view through the battery housing from Figure 1.

[0034] Detailed Description of Further Embodiments Further embodiments are described below with reference to the figures. Identical, similar, or equivalent elements in the different figures are provided with identical reference numerals, and a repeated description of these elements is partially omitted to avoid redundancies.

[0035] Figure 1 schematically shows a perspective side view of a partial area of ​​a battery housing 1. The view is directed from the interior of the battery housing onto the partial area.

[0036] The battery housing 1 is designed to accommodate a plurality of battery cells (not shown) to form a vehicle battery. The battery cells accommodated in the battery housing 1 can, for example, be organized into battery modules, each of which accommodates a subset of the battery cells.

[0037] The battery housing 1 comprises at least one housing wall 2 defining a housing interior with a vent opening 4 for discharging gases from the housing interior. The vent opening 4 serves to discharge any undesired excess pressure in the housing interior at a defined location on the housing wall 2 from the battery housing 1, for example, into the environment.

[0038] An undesirable overpressure inside the housing can occur, for example, due to thermal runaway of a battery cell. Such overpressure typically occurs suddenly and, if released into the environment in an undefined manner, could cause the battery housing 1 to rupture or burst at an unpredictable location, thus posing a hazard to persons.

[0039] Accordingly, a defined escape of the overpressure generating gases from the housing interior is achieved through the degassing opening 4.

[0040] The vent opening 4 is sealed with an adhesive film 6. The adhesive film 6 is glued directly to the housing wall 2.

[0041] The adhesive film 6 seals the vent opening 4, allowing the battery housing 1 to be gas-tight and liquid-tight. Sealing is important to protect the electrical and electronic components housed inside the housing from environmental influences. For example, moisture should be prevented from penetrating the housing to prevent corrosion and short circuits. Furthermore, the penetration of foreign matter such as dust or dirt should be prevented to prevent the formation of short circuits.

[0042] The battery housing 1 can be hermetically sealed against the environment.

[0043] To equalize the pressure of the battery housing 1 with respect to the environment in the event of a change in the ambient air pressure, for example, when the vehicle travels from one location to another at a different altitude, or due to changes in the general air pressure or temperature differences, a separate pressure equalization device can be provided, which is not described further here. However, the pressure equalization device can be provided in addition to the vent opening 4 described here.

[0044] Figure 2 schematically shows a further perspective side view of the partial area of ​​the battery housing 1 from Figure 1, wherein the adhesive film 6 is hidden in order to allow a view of the venting opening 4.

[0045] It can be seen that the battery housing 1 comprises a mandrel element 8 which is provided for perforating the adhesive film 6 in the event of an overpressure occurring during a thermal runaway of a battery cell.

[0046] The mandrel element 8 is arranged in the area of ​​the vent opening 4 in such a way that it perforates the adhesive film 6 when the adhesive film 6 deforms when the overpressure occurs. This then opens the vent opening 4, allowing the gas flow to escape from the housing interior into the environment.

[0047] When overpressure occurs, the adhesive film 6 gradually bulges accordingly and then, at the predetermined overpressure, impacts the mandrel element 8 in such a way that the adhesive film 6 is then perforated. In other words, when overpressure occurs, a portion of the bulged adhesive film 8 then moves toward the mandrel element 8, so that the adhesive film 8 then perforates itself at the mandrel element 8 when the predetermined overpressure is reached.

[0048] The adhesive film 8 is designed to be elastic enough that, when the overpressure occurs, it deforms to such an extent that the predetermined overpressure causes the perforation. The mandrel element 8 is arranged, for example, on a cross member 10 extending transversely to the housing wall 2. The mandrel element 8 is formed by a cutout 12 formed in the cross member 10.

[0049] The cross strut supporting the mandrel element 8 can be formed integrally with the housing wall 2. The mandrel element 8 is then formed integrally with the housing wall 2.

[0050] The mandrel element 8 is accordingly stationary and immobile relative to the housing wall 2. In particular, the mandrel element 8 does not move relative to the vent opening 4 or to a plane 14 defined by the vent opening 4.

[0051] The housing wall 2 and the cross strut 2 can be part of a one-piece profile structure, as shown by way of example in Figures 2 and 3.

[0052] With respect to the housing wall 2, the adhesive film 6 is glued to the inside of the housing wall 2 facing the housing interior and the mandrel element 8 is arranged on the outside with respect to the housing wall 8.

[0053] Figure 3 shows a schematic sectional view 1 through the battery housing from Figure 1 at the level of the venting opening 4 centrally through the cross strut 10. The formation of the mandrel element 8 by means of the cutout 12 made in the cross strut 10 can be seen.

[0054] A tip 9 of the mandrel element 8 is arranged at a predetermined distance 16 from a plane 14 of the adhesive film 6 defined by the degassing opening 4 in the unpressurized state.

[0055] The mandrel element 8, more precisely its tip 9, is arranged in such a way that it comes into contact with the adhesive film 6 when the overpressure in the housing interior reaches a predetermined value and a part of the adhesive film 6 has bulged accordingly towards the tip 9.

[0056] The adhesive film 6 is designed to deform toward the mandrel element 8 due to an excess pressure present inside the housing, optionally essentially elastically in this case. The adhesive film 6 can thus contribute to pressure equalization between the interior and exterior of the housing until the tip 9 is reached, i.e., until the predetermined distance is overcome.

[0057] Where applicable, all individual features presented in the embodiments may be combined and / or interchanged without departing from the scope of the invention.

[0058] 1 battery case

[0059] 2 Housing wall

[0060] 4 Degassing opening 6 Adhesive film

[0061] 8 mandrel element

[0062] 9 top

[0063] 10 cross brace

[0064] 12 Recess 14 Level

[0065] 16 Distance

Claims

Claims 1. Battery housing (1) for accommodating a plurality of battery cells to form a vehicle battery, comprising at least one housing wall (2) defining a housing interior with a venting opening (4) for discharging gases from the housing interior, characterized in that the venting opening (4) is closed by an adhesive film (6) glued to the housing wall (2) and a mandrel element (8) is provided for perforating the adhesive film (6) in the event of the occurrence of excess pressure during a thermal runaway of a battery cell.

2. Battery housing (1) according to claim 1, characterized in that the mandrel element (8) is arranged in the region of the venting opening (4) in such a way that it perforates the adhesive film (6) when the adhesive film (6) is deformed when the overpressure occurs, and / or the mandrel element (8) is arranged in such a way that it comes into contact with the adhesive film (6) when the overpressure in the housing interior reaches a predetermined value, and / or the adhesive film (6) is designed to deform, in particular elastically and / or plastically deform, towards the mandrel element (8) due to an overpressure present in the housing interior.

3. Battery housing (1) according to claim 1 or 2, characterized in that the mandrel element (8) is arranged on a cross strut (10) extending transversely to the housing wall (2) on a side of the housing wall (2) opposite the housing interior, wherein the mandrel element (8) is formed in particular by a cutout (12) made in the cross strut (10).

4. Battery housing (1) according to one of the preceding claims, characterized in that the mandrel element (8) is arranged immovably relative to the venting opening (4).

5. Battery housing (1) according to one of the preceding claims, characterized in that the mandrel element (8) is formed integrally with the housing wall (2).

6. Battery housing (1) according to one of the preceding claims, characterized in that a tip (9) of the mandrel element (8) is arranged at a predetermined distance (16) from a plane (14) of the adhesive film (6) predetermined by the degassing opening (4) in the unpressurized state.

7. Battery housing (1) according to one of the preceding claims, characterized in that the adhesive film (6) is glued to an inner side of the housing wall (2) facing the housing interior and / or the mandrel element (8) is arranged on a side of the housing wall (2) opposite the housing interior.

8. Battery housing (1) according to one of the preceding claims, characterized in that the battery housing (1) comprises a profile structure, wherein the housing wall (2), the venting opening (4) and the mandrel element (8) are formed in the profile structure.

9. Battery housing (1) according to one of the preceding claims, characterized in that the housing wall (2) and the cross strut (10) or the housing wall (2), the cross strut (10) and the mandrel element (8) are formed integrally with one another.

10. A vehicle battery comprising a plurality of battery cells and a battery housing (1) enclosing the plurality of battery cells according to one of the preceding claims.

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