Housing wall part with integrated safety valve for a battery housing, support frame for a battery housing and battery housing

Abstract

Housing wall part with integrated safety valve for a battery housing (4), comprising: - a film (1) extending along a plane, comprising an inner film side (11) and an opposite outer film side (12); and - at least one plastic wall (2) with: -- a frame part (21); -- at least one flap part (23); and -- at least one hinge part (25), wherein the frame part (21) and the at least one flap part (23) are designed to partially cover the film outer side (12) and are each connected to the film outer side (12) in a load-bearing manner to form an outer side (22) of the plastic wall (2), wherein the frame part (21) is designed to surround the at least one flap part (23) in the plane of extension, wherein between the at least one flap part (23) and the frame part (21) a free space (20) surrounding the respective flap part (23) is formed, in which the film outer side (12) runs exposed, and wherein each flap part (23) is connected to the frame part (21) in a partial region of a circumference (231) along the plane of the respective flap part (23) via at least one hinge part (25).

Description

[0001] The present invention relates to a housing wall part with an integrated safety valve for a battery housing as well as a support frame for a battery housing and furthermore a battery housing.

[0002] Housing wall components for battery housings as well as battery housings for accommodating a plurality of individual battery cells are already known from the prior art. Such battery housings are used, for example, in the field of electromobility, particularly for electrically powered vehicles such as electric cars. The battery housing forms an interior space that is separated from the surrounding environment and accommodates a plurality of individual battery cells. The interior space is fluid-tightly demarcated by surrounding housing walls. In the prior art, the housing walls are usually made of metallic materials in order to provide suitable protection for the accommodated battery cells against external forces, for example in the event of an accident.

[0003] The battery housings also serve to provide electromagnetic shielding and protection against thermal runaway of the individual battery cells. It is already known from the prior art to provide so-called safety valves in the aforementioned battery housings. In the event of thermal runaway, for example, in the event of a fire within the battery housing, the fire particles generated within the battery housing and any fluids expelled from the battery cells are discharged from the interior of the battery housing to the environment in a controlled manner. The safety valves serve to prevent a pressure increase within the interior of the battery housing above a specified level, thus preventing the battery housing from bursting.The fire particles and fluids are to be controlled via the safety valve and discharged from the interior of the battery housing in specific areas in such a way that any occupants of an electric vehicle can safely leave the vehicle interior and escape from the damaged vehicle even in the event of thermal runaway of battery cells.

[0004] A disadvantage of the safety valves known from the prior art is that they are often separate assemblies that must be fluid-tightly connected to the battery housing or attached to it. In the prior art, appropriate installation space must be provided for the construction of the safety valves. Due to the low level of integration of the safety valves according to the prior art, a significant amount of effort is required during production to securely connect the safety valves to the battery housing, and specifically to a housing wall of the battery housing. Furthermore, a large amount of installation space is required for the arrangement of the safety valves.

[0005] Based on the aforementioned disadvantages of the prior art, the present invention is based on the object of providing an improved housing wall part for a battery housing with a safety valve, which requires less effort in the manufacture of the battery housing and, moreover, reduces the design effort for integrating the safety valves.

[0006] According to the invention, the above-mentioned object is achieved according to a first aspect of the present invention by a housing wall part with an integrated safety valve for a battery housing.

[0007] The housing wall part according to the invention comprises a film extending along a plane, having a film inner side and an opposite film outer side, as well as at least one plastic wall with a frame part, at least one flap part, and at least one hinge part. The frame part and the at least one flap part are designed to partially cover the film outer side and are each connected to the film outer side in a load-bearing manner to form an outer side of the plastic wall. The frame part is in the film orformed parallel to the plane of extension of the film surrounding the at least one flap part, wherein between the at least one flap part and the frame part a free space surrounding the respective flap part is formed, in which the outer side of the film runs exposed and wherein each flap part is connected to the frame part in a partial region of a circumference along the plane of extension of the respective flap part via at least one hinge part.

[0008] According to the invention, the plastic wall is applied to the outer side of the film, which wall is formed according to the invention from at least one frame part, at least one flap part, and at least one hinge part. On the outer side of the film, the frame part and the at least one flap part are designed to extend flatly along or on the outer side parallel to the plane of the film. In the free space formed between the frame part and the at least one flap part, the outer side of the film is exposed and is covered neither by the frame part nor by the at least one flap part.

[0009] In the areas of the free spaces or the at least one free space, the plastic wall consequently has a recess in which the film is exposed to the outside. In the areas of the free spaces, the housing wall is thus formed according to the invention solely by the film layer. In the free space between the frame part and the respective flap part, at least one hinge part is further arranged according to the invention, which at least partially bridges the free space and creates a connection between the frame part and the at least one flap part.

[0010] The safety valve according to the invention is formed by the claimed housing wall part and its components. The integrated safety valve according to the invention is based on the following functionality: According to the invention, a housing wall part is formed that is fluid-tight in the initial state and can form a portion of the housing wall of an entire battery housing, which encloses a fluid-tight, delimited interior space in which a plurality of individual battery cells are arranged. The film inner side of the housing wall part according to the invention faces the interior space and the battery cells accommodated therein; particularly preferably, the film forms, at least in sections, the inner wall of the battery housing that delimits the interior space.In the event of failure, particularly in the event of thermal runaway, of at least one battery cell in the interior, fluids and / or particles suddenly escape from the defective battery cell(s), initially collecting in the interior of the battery housing, with the pressure within the battery housing increasing progressively. The film provided according to the invention is designed in terms of its material properties and dimensions such that the film, together with the at least one flap part applied to the film's outer side, can elastically deform and bulge or protrude in the area bounded by the frame part, initially toward the outer side of the housing wall.If a defined maximum pressure is exceeded within the interior of the battery housing and in the area of ​​the inner side of the film, the film will fail locally in the area of ​​at least one free space between the at least one flap part around the frame part and / or between the multiple flap parts of the plastic wall. Due to the load-bearing connection and arrangement of the frame part and the at least one flap part, the film is supported or reinforced in the aforementioned area, and there will be no failure of the film in the aforementioned area in which the at least one hinge part or the frame part is arranged.The pressure can already partially escape via the locally failed and perforated areas of the film in the area of ​​the aforementioned free spaces, whereby the internal pressure continues to press the at least one flap part towards the outside of the plastic wall and leads to a bursting of the structure, whereby the at least one hinge part ensures that the respective at least one flap part pivots outwards relative to the frame part but remains connected to the frame part via the hinge part in a load-bearing manner. In the event of bursting, an opening delimited by the frame part is created between the interior of the battery housing and the outside of the plastic wall, at the edge of which opening the at least one flap part protrudes pivoted towards the outside. The frame part is connected to the remaining housing wall in a load-bearing manner. In the event of bursting, the at least one hinge part acts as a pivot axis for the respective flap part.

[0011] According to the invention, a plurality of flap parts can be formed which are formed adjacent to one another in the plane of extension or parallel to the plane of extension on the outside of the film, and wherein a free space is formed between the flap parts surrounding the respective flap part, in which free space the film runs exposed on the outside of the film. In the free space between the frame part and the at least one flap part or between the flap parts, the film on the outside of the film is covered neither by the frame part nor by the at least one flap part and thus runs exposed. A recess is thus formed in the plastic wall in the region of the free spaces, in which only the film extends along its plane of extension.

[0012] The at least one hinge part can extend flatly along the plane of the film and cover the outer side of the film, preferably resting on the outer side of the film.

[0013] According to the invention, the at least one hinge part can be connected to the outer side of the film in a load-bearing manner.

[0014] The at least one hinge part can have a smaller material thickness orthogonal to the plane of the film compared to the at least one flap part and / or the frame part.

[0015] The frame part and / or the at least one flap part is advantageously connected to the outer side of the film in a load-bearing manner over its entire surface along the plane of travel.

[0016] Preferably, the frame part and / or the at least one flap part and / or the at least one hinge part can each be formed as injection-molded parts; particularly preferably, the aforementioned parts can be formed as an integral, one-piece injection-molded part.

[0017] Again preferably, the frame part and / or the at least one flap part and / or the at least one hinge part can be formed from a plastic material, particularly preferably from a thermoplastic plastic material.

[0018] The frame part and / or the at least one flap part and / or the at least one hinge part can comprise a hybrid material structure comprising at least a first component formed from a plastic and a second component formed from a stiffening material to increase the mechanical properties.

[0019] The frame part and / or the at least one flap part and / or the at least one hinge part can be formed at least in sections as a fiber-reinforced plastic part.

[0020] According to the invention, it can be provided that the frame part and / or the at least one flap part and / or the at least one hinge part are made of fiber-reinforced prepreg material.

[0021] Particularly preferably, it can be provided that the housing wall part additionally has at least one pressure equalization device, with at least one opening in the film and at least one opening in the plastic wall for forming at least one pressure equalization channel between the inside of the film and the outside of the plastic wall, wherein a hydrophobic fluid-permeable membrane is arranged in the at least one pressure equalization channel.

[0022] According to the invention, it can also be provided to provide the at least one pressure equalization channel through the plastic wall and to perforate the film in the region of the at least one pressure equalization channel to form a plurality of passage openings in the film to form the pressure equalization channel.

[0023] The hydrophobic fluid-permeable membrane can preferably be provided between the housing wall and the film, in particular on the outer side of the film.

[0024] The housing wall part according to the invention can preferably further comprise a protective cage structure which is formed on the outer side of the plastic wall and which covers the at least one flap part and the free space surrounding the respective flap part, in which the film runs uncovered to the outer side, in a grid-like manner to define a protective space.

[0025] The protective cage structure can further comprise a piercing device that protrudes into the protective space and tapers toward the outer side of the film. The piercing device can be formed by at least one mandrel, with a tip of the mandrel protruding from the protective cage structure toward the outer side of the film. The piercing device can further be formed by at least one blade, with a cutting edge of the blade protruding from the protective cage structure toward the outer side of the film. The tip of the mandrel and / or the cutting edge of the blade are spaced a short distance from the plane of travel of the film or the outer side of the film.

[0026] The film can be designed to be fluid-tight. Furthermore, the film can be designed as a metal foil made of a metal or a metal alloy. Alternatively, however, the film can also be designed as a plastic film. The plastic film can include a metallic coating.

[0027] Preferably, the film can be formed from a fiber composite material.

[0028] According to the invention, it can be provided that the film has a failure behavior which has a lower temperature dependence compared to the failure behavior of the plastic wall.

[0029] The housing part according to the invention can further comprise a piercing device for the film, wherein the piercing device is arranged in the region of the outer side of the plastic wall or in front of the outer side of the plastic wall and projects in a tapered manner toward the outer side of the film. The piercing device can in turn be designed at least as a mandrel with a tip projecting toward the outer side of the film and / or as a blade with a cutting edge projecting toward the outer side of the film. The tip of the mandrel and / or the cutting edge of the blade are spaced a short distance from the plane of travel of the film or the outer side of the film.

[0030] According to a second aspect, the present invention relates to a support frame for a battery housing for receiving battery modules, wherein the support frame comprises a circumferential frame body for defining a frame interior and at least one cross member and / or at least one longitudinal member strut, which are arranged within the frame interior and are connected to the circumferential frame body to form a plurality of receiving compartments for battery modules within the frame interior, wherein the frame body and / or the support struts comprise a housing wall part according to an embodiment of the first aspect of the present invention.

[0031] According to a third aspect, the present invention relates to a battery housing comprising a support frame and a lower and / or upper battery housing cover, wherein the lower and / or upper battery housing cover can be sealingly connected to the support frame to form a battery housing interior sealed against the environment, wherein the support frame and / or the lower or upper battery housing cover comprises a housing wall part according to the first aspect of the present invention.

[0032] In the following, exemplary embodiments of the housing wall according to the invention and of the battery housing are explained with reference to the attached figures.

[0033] They show: Fig. 1A an external view of an exemplary first embodiment of a housing wall part according to the invention with integrated safety valve; Fig. 1B a perspective view of the housing wall part according to the invention according to Fig. 1A; Fig. 1C the housing wall part according to the invention according to the Fig. 1A and Fig. 1B in the burst state; Fig. 2 a perspective view of a second exemplary embodiment of a housing wall part according to the invention; Fig. 3A is a partially perspective sectional view of a third exemplary embodiment of a housing wall part according to the invention; Fig. 3B is a partial view of the protective cage structure according to Fig. 3A; Fig. 4 shows a further exemplary embodiment of a housing wall part according to the invention in a perspective view; Fig. 5 shows a further embodiment of a housing wall part according to the invention; and Fig. 6 a battery housing according to the invention.

[0034] The Fig. 1A shows a schematic view of a first exemplary embodiment of a housing wall part according to the invention with integrated safety valve for a battery housing in an external view, wherein the Fig. 1B the illustrated embodiment according to Fig. 1A in perspective view, wherein the film 1 has been spaced apart from the other housing wall parts 2 for better illustration and comprehensibility. With reference to the Fig. 1A and Fig. 1B, the housing wall part according to the invention comprises a film 1 extending along a plane with a film inner side 11 and an opposite film outer side 12 as well as at least one plastic wall 2 with a frame part 21, at least one flap part 23 and at least one hinge part 25. The exemplary embodiment according to the Fig. 1A and Fig. 1B has four flap parts 23. The frame part 21 and the at least one flap part or the four illustrated flap parts 23 partially cover the film outer side 12 and are each connected to the film outer side 12 in a load-bearing manner to form an outer side 22 of the plastic wall. The frame part 21 surrounds the four exemplary flap parts 23 provided in the plane of the film 1, wherein a free space 20 surrounding the respective flap part is formed between the flap parts 23 and the frame part 21, in which free space the film outer side 12 extends exposed towards the outer side 22. Each flap part 23 is connected to the frame part via at least one hinge part 25 in a partial region of the circumference 231 along the plane of the film of the respective flap part.As shown, according to the invention a plurality of flap parts 23 can be formed which are formed adjacent to one another in the plane of the film 1, for example to form the flap part 23 shown in FIG. Fig. 1A and Fig. 1B, wherein between the plurality of flap parts 23 a free space 20 is formed surrounding the respective flap part 23, in which the film 1 runs exposed on the film outer side 12 and is accordingly not covered by a frame part or flap part. Fig. 1A and Fig. 1B, the provided hinge parts 25 bridge the above-mentioned free space 20 to form a joint or a pivot axis between a peripheral area 231 of the respective flap part 23 and the frame part 21. As in the Fig. 1C, the hinge parts 25 serve to form a hinge between the flap parts 23 and the frame part 21, so that in the event of an overpressure occurring on the film inner side 11, which faces an interior of a battery housing and thus also faces the battery cells to be accommodated, a high pressure, for example in the event of thermal runaway, can occur. The film 1 provided in the region of the free spaces 20 can tear or perforate and, due to the internal pressure applied on the film inner side 11 of the film 1, the plurality of flap parts 23 can be pivoted forward relative to the frame part 21 in the direction of the outer side 22 of the plastic wall in order to correspondingly form an opening in the housing wall or in the battery housing, which opening encompasses the housing wall according to the invention.The hinge parts 25 can extend flatly along the plane of the film 1 and in particular cover the outer side 12 of the film in the region of the free spaces 20. Particularly preferably, the hinge parts 25 can also be connected to the outer side 12 of the film in a load-bearing manner. According to the invention, it can also be provided that the frame part 21 and / or the flap parts 23 are each connected over their entire surface to the outer side 12 of the film along the plane of the film 1 in a load-bearing manner, for example by being glued to the outer side of the film or by being injection-molded directly onto the film. In this regard, the frame part 21 and / or the at least one flap part 23 and / or the at least one hinge part can each be provided as injection-molded parts, particularly preferably as a one-piece injection-molded part. As is particularly the case with the . Fig. 1A and Fig. 1B, in the aforementioned one-piece injection molding, the provision of the hinge parts 25 serves as a flow channel between the frame part 21 and the flap parts 23.

[0035] The Fig. Figure 2 shows a perspective view of a second exemplary embodiment of a housing wall part according to the invention. The illustrated embodiment according to Fig. 2 differs from the embodiment according to Fig. 1 in that the housing wall part further comprises a protective cage structure 29, which is formed on the outer side 22 of the plastic wall 2 and which overlaps the at least one flap part or the four flap parts 23 and the free space 20 in a grid-like manner to define a protective space 290. In the Fig. 2, the protective cage structure is formed in two parts, consisting of a surrounding collar and a cover part. The cover part of the protective cage structure 29 has a plurality of through-openings.

[0036] In the Fig. 3A and 3B show a further embodiment of a housing wall part according to the invention, wherein the embodiment according to the Fig. 3A and Fig. 3B from the embodiment according to Fig. 2 in that the protective cage structure 29 further comprises a piercing device 291, which projects into the protective space 290 and is tapered towards the outer side 12 of the film. Fig. 3A shows the exemplary piercing device 291, which is formed by a mandrel 2910, with a tip 2911 of the mandrel 2910 protruding from the protective cage structure 29 toward the film outer side 12. Alternatively, the piercing device 291 can also be blade-shaped with at least one protruding cutting edge, which, however, is not shown in the figures.

[0037] The Fig. 3B again shows the cover of the protective cage structure 29 comprising a central mandrel 2910 with the tip 2911, which protrudes from the protective cage structure 29 in the direction of the film outer side 12.

[0038] The Fig. 4 shows a further exemplary embodiment of a housing wall part according to the invention, which differs from the exemplary embodiment according to the Fig. 1 in that the housing wall part further comprises a pressure equalization device 27 with a plurality of openings 10 in the film 1 and an opening 26 in the plastic wall 2 for forming at least one pressure equalization channel between the film inner side 11 and the outer side 22 of the plastic wall, wherein a hydrophobic fluid-permeable membrane 3 is arranged in the at least one pressure equalization channel.

[0039] The Fig. 5 shows a further exemplary embodiment of a housing wall part with integrated safety valve, but the geometric design of the safety valve to the Fig. 1 is designed differently. The frame part surrounds the number of eight pie-shaped flap parts 23, wherein the flap parts 23 are each connected to the frame part 21 at their outer edge via a hinge part 25.

Claims

[1] Housing wall part with integrated safety valve for a battery housing (4), comprising: - a film (1) extending along a plane, comprising an inner film side (11) and an opposite outer film side (12); and - at least one plastic wall (2) with: -- a frame part (21); -- at least one flap part (23); and -- at least one hinge part (25), wherein the frame part (21) and the at least one flap part (23) are designed to partially cover the film outer side (12) and are each connected to the film outer side (12) in a load-bearing manner to form an outer side (22) of the plastic wall (2), wherein the frame part (21) is designed to surround the at least one flap part (23) in the plane of extension, wherein between the at least one flap part (23) and the frame part (21) a free space (20) surrounding the respective flap part (23) is formed, in which the film outer side (12) runs exposed, and wherein each flap part (23) is connected to the frame part (21) in a partial region of a circumference (231) along the plane of the respective flap part (23) via at least one hinge part (25). [2] Housing wall part according to claim 1, wherein a plurality of flap parts (23) are formed which are formed adjacent to one another in the plane of extension and wherein between the flap parts (23) a free space (20) surrounding the respective flap part (23) is formed, in which the film (1) runs exposed on the film outer side (12). [3] Housing wall part according to claim 1 or 2, wherein the at least one hinge part (25) extends flatly along the plane of extension and covers the outer side (12) of the film, preferably resting on the outer side (12) of the film. [4] Housing wall part according to one of the preceding claims, wherein the at least one hinge part (25) is connected to the film outer side (12) of the film (1) in a load-bearing manner. [5] Housing wall part according to one of the preceding claims, wherein the at least one hinge part (25) orthogonal to the plane of extension has a smaller material thickness than the at least one flap part (23) and / or the frame part (21). [6] Housing wall part according to one of the preceding claims, wherein the frame part (21) and / or the at least one flap part (23) is / are connected to the film outer side (12) in a load-bearing manner along the plane of extension over its entire surface. [7] Housing wall part according to one of the preceding claims, wherein the frame part (21) and / or the at least one flap part (23) and / or the at least one hinge part (25) are each formed as injection-molded parts. [8] Housing wall part according to one of the preceding claims, wherein the frame part (21) and / or the at least one flap part (23) and / or the at least one hinge part (25) are formed as a one-piece injection-molded part. [9] Housing wall part according to one of the preceding claims, wherein the frame part (21) and / or the at least one flap part (23) and / or the at least one hinge part (25) are formed from a plastic material, preferably from a thermoplastic plastic material. [10] Housing wall part according to one of the preceding claims, wherein the frame part (21) and / or the at least one flap part (23) and / or the at least one hinge part (25) comprise a hybrid material structure comprising at least a first component formed from a plastic and a second component formed from a stiffening material to increase the mechanical properties. [11] Housing wall part according to one of the preceding claims, wherein the frame part (21) and / or the at least one flap part (23) and / or the at least one hinge part (25) is formed at least in sections as a fiber-reinforced plastic component. [12] Housing wall part according to one of claims 1 to 6, wherein the frame part (21) and / or the at least one flap part (23) and / or the at least one hinge part (25) is made of fiber-reinforced prepreg material. [13] Housing wall part according to one of the preceding claims, additionally comprising at least one pressure equalization device (27) with at least one opening (10) in the film (1) and at least one opening (26) in the plastic wall (2) for forming at least one pressure equalization channel between the film inner side (11) and the outer side (22) of the plastic wall (2), wherein a hydrophobic fluid-permeable membrane (3) is arranged in the at least one pressure equalization channel. [14] Housing wall part according to one of the preceding claims, additionally comprising a protective cage structure (29) which is formed on the outer side (22) of the plastic wall (2) and which overlaps the at least one flap part (23) and the free space (20) in a grid-like manner to define a protective space (290). [15] Housing wall part according to claim 14, wherein the protective cage structure (29) has a piercing device (291) which projects into the protective space (290) and is tapered in the direction of the film outer side (12). [16] Housing wall part according to claim 15, wherein the piercing device (291) is formed by at least one mandrel (2910), wherein a tip (2911) protrudes from the protective cage structure (29) in the direction of the film outer side (12) and / or formed by at least one blade, wherein a cutting edge protrudes from the protective cage structure (29) in the direction of the film outer side (12). [17] Housing wall part according to one of the preceding claims, wherein the film (1) is fluid-tight. [18] Housing wall part according to one of the preceding claims, wherein the foil (1) is designed as a metal foil which is formed from a metal or a metal alloy. [19] Housing wall part according to one of claims 1 to 17, wherein the film (1) is designed as a plastic film. [20] Housing wall part according to one of the preceding claims, wherein the film (1) is formed from a fiber composite material. [21] Housing wall part according to one of the preceding claims, wherein the film (1) has a failure behavior which has a lower temperature dependence than the plastic wall. [22] Housing wall part according to one of the preceding claims, further comprising a piercing device (291) for the film (1), wherein the piercing device (291) is arranged in the region of the outer side (22) of the plastic wall (2) or in front of the outer side (22) of the plastic wall (2) and projects in a tapered manner in the direction of the film outer side (12). [23] Housing wall part according to claim 22, wherein the piercing device (291) is designed as at least one mandrel (2910) with a tip (2911) projecting in the direction of the outer side (12) of the film and / or at least one blade with a cutting edge projecting in the direction of the outer side of the film. [24] Support frame (40) for a battery housing (4) for receiving battery modules (5), comprising: - a surrounding frame body (400) for defining a frame interior (402); and - at least one cross member strut and / or at least one longitudinal member strut, which are arranged within the frame interior (401) and are connected to the circumferential frame body (400) to form a plurality of receiving compartments for battery modules (5) within the frame interior (401), wherein the frame body (400) and / or the support struts have a housing wall part according to one of claims 1 to 23. [25] Battery housing (4) comprising: - a support frame (40), and - a lower and / or upper battery housing cover (41, 42); wherein the lower and / or upper battery housing cover (41, 42) can be sealingly connected to the support frame (40) to form a battery housing interior (405) sealed against the environment, wherein the support frame (409) and / or the battery housing cover (41, 42) have a housing wall part according to one of claims 1 to 23.

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