Venting and separating device for a battery housing

Abstract

Venting and separating device (100) for a housing (50) of a battery, in particular a traction battery of a motor vehicle, comprising a base body (10) with a circumferential rim (12) which is intended for coupling to the housing (50), wherein the base body (10) has at least one inlet opening (14) and at least one outlet opening (18), wherein the at least one inlet opening (14) can be brought into fluid contact with an interior (58) of the housing (50) when mounted as intended, and the at least one outlet opening (18) is in fluid contact with an environment (80), wherein the base body (10) has at least one first separating grid (20) with first grid openings (22) extending over the inlet opening (14) and, in a venting flow direction (24) downstream of the first separating grid (20) extending over the outlet opening (18), has a second separating grid (30) with second grid openings (32), wherein the venting separator device (100) has at least one overpressure valve (40) which is configured to open a bypass fluid flow path (26) from the interior (58) of the housing (50) to the environment (80) when a predetermined overpressure in the housing (50) is exceeded, wherein the bypass fluid flow path (26) bypasses at least one of the separator grids (20, 30), and wherein the pressure relief valve (40) is formed by the fact that the base body (10) in an assembly state can be pressed against the housing (50) in a sealing manner via at least one pre-tensioned spring element (42), wherein, when the predetermined overpressure in the housing (50) is exceeded, the base body (10) can be lifted off the housing (50) against the pre-tensioned spring element (42) by opening the bypass fluid flow path (26).

Description

Technical field

[0001] The invention relates to a venting and separation device for a battery housing, in particular a traction battery of a motor vehicle, and to a battery housing, in particular a traction battery of a motor vehicle, for receiving battery cells. State of the art

[0002] Enclosures for electronic components, such as battery cells, are typically not completely gas-tight from the environment. This is necessary to allow gas exchange between the interior and exterior, both to compensate for temperature fluctuations (e.g., from heat generated during charging and discharging) and naturally occurring atmospheric pressure fluctuations, particularly in mobile systems. This gas exchange prevents impermissible mechanical stress on the enclosure, especially bursting or bulging. Furthermore, battery enclosures, in particular, require an emergency venting function to prevent sudden pressure increases due to battery cell failure, as otherwise the enclosure could be damaged.

[0003] Equally important, however, is the effective prevention of the ingress of foreign matter, dirt, and moisture in the form of liquid water. Therefore, pressure equalization devices are known that incorporate semipermeable membranes, for example, made of extruded polytetrafluoroethylene (PTFE), which are permeable to gas but impermeable to liquids.

[0004] From DE 10 2012 022 346 B4, a degassing unit for a battery housing is known, comprising a base body with a gas passage opening covered by a semipermeable membrane that is permeable to gases but impermeable to liquids. The membrane is fixedly and fluid-tightly connected to the base body, in particular by welding. The base body can be fluid-tightly connected to a pressure equalization opening of the battery housing. Gas exchange is ensured by the membrane's semipermeable properties during normal operation. To implement an emergency degassing function, an emergency degassing pin pointing towards the membrane is arranged on a cover body. This pin perforates and ruptures the membrane when a limit strain induced by the internal housing pressure is exceeded, thus enabling a sudden pressure equalization from the interior to the environment.On an inner side facing the battery housing in an assembly state, an inner protective grid is connected to the base body, which is intended to prevent foreign objects from entering the battery housing and which supports the membrane against water pressure from the outside.

[0005] From DE 10 2021 100 659 A1 a battery housing with energy storage space and separation space with at least one separation element for particles is known, wherein a flow path leads from the energy storage space through the separation space and a vent opening into an environment.

[0006] German patent DE 10 2013 208 137 A1 describes a battery with a plurality of cells and associated degassing elements for releasing pressure when a predetermined gas pressure is exceeded. A battery cover has predetermined breaking points that correspond to the individual degassing elements.

[0007] Further venting and separating devices are known from CN 1 12 310 552 A, CN 2 10 467 960 U and CN 1 12 751 121 A. Disclosure of the invention

[0008] One object of the invention is to create a venting and separation device for a battery housing, in particular a traction battery of a motor vehicle, which allows rapid venting of the housing with low pressure loss and prevents the uncontrolled release of particles.

[0009] Another task is to create a battery housing that allows for rapid venting with low pressure loss and prevents the uncontrolled release of particles.

[0010] The aforementioned problem is solved according to one aspect of the invention by a venting and separating device for a battery housing, in particular a traction battery of a motor vehicle, comprising a base body with a circumferential rim which is provided for coupling to the housing, wherein the base body has at least one inlet opening and at least one outlet opening, wherein the at least one inlet opening can be brought into fluid contact with an interior of the housing when mounted on the housing as intended, and the at least one outlet opening is in fluid contact with an environment, wherein the base body, extending over the inlet opening, has at least one first separating grid with first grid openings, and in a venting flow direction downstream of the first separating grid, extending over the outlet opening, has a second separating grid with second grid openings.wherein the venting separator device has at least one overpressure valve which is configured to open a bypass fluid flow path from the interior of the housing to the environment when a predetermined overpressure in the housing is exceeded, wherein the bypass fluid flow path bypasses at least one of the separator grids, and wherein the overpressure valve (40) is formed in such a way that the base body (10) can be pressed against the housing (50) in an assembly state via at least one pre-tensioned spring element (42) in a sealing manner, wherein when the predetermined overpressure in the housing (50) is exceeded, the base body (10) can be lifted off the housing (50) against the pre-tensioned spring element (42) by opening the bypass fluid flow path (26).

[0011] The fact that the inlet opening of the base body can be brought into fluid contact with the interior of the housing during proper assembly can mean either that it is always in fluid contact with the interior of the housing during assembly, or that the fluid connection between the interior of the housing and the inlet opening of the base body is only established during an emergency degassing event, for example, by the activation of a pressure relief valve and / or the rupture of a diaphragm or rupture disc. In other words, for the characteristic "can be brought into fluid contact," it is sufficient if the base body can be mounted on the housing in such a way that its inlet opening is able to be in fluid contact with the interior of the housing in at least some of the housing's operating states.

[0012] The further problem is solved according to a further aspect of the invention by a housing of a battery, in particular a traction battery of a motor vehicle, for receiving battery cells, which has at least one housing wall with at least one housing opening, wherein the housing opening is closed by a venting separator device, in particular on an outside of the housing wall.

[0013] Favorable embodiments and advantages of the invention will become apparent from the further claims, the description and the drawing.

[0014] According to one aspect of the invention, a venting and separating device for a battery housing, in particular a traction battery of a motor vehicle, is provided, comprising a base body with a circumferential rim which is provided for coupling to the housing, wherein the base body has at least one inlet opening and at least one outlet opening, wherein the at least one inlet opening, when properly mounted on the housing, is in fluid communication with an interior of the housing, and the at least one outlet opening is in fluid communication with an environment. The base body has, extending over the inlet opening, at least one first separating grid with first grid openings, and, in a venting flow direction downstream of the first separating grid and extending over the outlet opening, a second separating grid with second grid openings.

[0015] The venting separator device has at least one pressure relief valve configured to open a bypass fluid flow path from the interior of the housing to the environment when a predetermined overpressure in the housing is exceeded, wherein the bypass fluid flow path bypasses at least one of the separator grids. In other words, the bypass fluid flow path branches off at a point in the venting flow direction that is at least upstream (or "upstream") of one of the separator grids.

[0016] In exemplary embodiments, the circumferential edge of the base body, via which the base body is coupled to the housing, is essentially fluid-tight. In other embodiments, however, a gap may also exist between the edge of the base body and the housing. "Coupled" can refer to a detachable or permanent connection, but in particular to a pressing of the edge of the base body against the housing.

[0017] The proposed venting and separating device serves to separate particles above a certain size from hot gas streams, which can typically exceed 200 °C. The actual outgoing fluid flow is not additionally obstructed, so that the pressure drop does not increase unacceptably due to the particles deposited on the filter. The venting and separating device can advantageously have a particularly flat design.

[0018] The venting and separating device includes a pressure relief valve, which allows any overpressure that occurs in the event of a fault to be quickly relieved in order to prevent damage to the housing. For example, this could be a housing for lithium-ion batteries, where gases released in the event of a cell defect must be vented from the housing very quickly. Often, however, it is necessary to prevent the particles released with the gases during a fault from escaping into the environment.

[0019] The venting and separating device, which may preferably be made primarily of sheet metal, can be mounted, for example, on the outside of the housing in the area of ​​housing openings, in order to prevent the escape of particles into the environment simply and cost-effectively. This is made possible by at least two separating grids provided on and / or in a base body of the venting and separating device, through which the escaping gas must flow to reach the environment. The separating grids are designed to effectively retain the particles so that they remain within the venting and separating device.

[0020] It is possible to connect several separator grids in series, allowing flow through them, in order to, for example, gradually separate the largest particles down to the finest. Sufficient sealing between the base body and the separator grid, or between the base body and the housing and the surrounding environment, is a prerequisite.

[0021] Furthermore, a bypass function in the form of a pressure relief valve can be integrated into the main body, in case the particles clog the separator grids to such an extent that an unacceptably high pressure would occur inside the housing. It is also conceivable to integrate a rupture disc, which opens under sufficient overpressure, into the venting separator. This can be made of metal or thermoplastic materials, for example. If the material is sufficiently permeable to air due to a microporous structure, the venting separator can also ensure permanent pressure equalization between the ambient environment and the inside of the housing during normal operation.

[0022] In this way, it is possible to implement a very cost-effective venting and separation device for particles, whereby the size distribution, quantity, and / or weight of the particles can be adapted to the requirements by selecting appropriate separators and dimensions, such as surface area, length, and diameter, and the pressure drop in the system can be optimized. Furthermore, the venting and separation device can be easily mounted externally onto the battery housing and offers the possibility of integrating additional functions, such as a rupture disc, permanent pressure equalization, and a bypass in case the separator grids become clogged.

[0023] The proposed venting and separation device advantageously allows for the effective separation of particles that, in the event of a malfunction of internal components, such as lithium-ion cells in a high-voltage storage system, are carried out of the housing along with the gases generated for pressure relief, thus preventing them from escaping into the environment. The venting and separation device represents a cost-effective, robust, scalable solution that can be optimized with regard to particle separation and pressure loss. This enables the venting and separation device to capture particles, particularly hot (lithium) particles, which are released from one or more battery cells in the event of a cell defect, preventing their uncontrolled release into the environment.

[0024] In a preferred embodiment, the bypass fluid flow path bypasses both separating grids. In other words, the bypass fluid flow path branches off at a point in the venting flow direction that is upstream of both the first and the second separating grid.

[0025] According to the invention, the pressure relief valve is formed by the fact that, in an assembled state, the base body can be pressed against the housing in a sealing manner by means of at least one pre-tensioned spring element. This allows the base body to be lifted from the housing when an overpressure is specified by the spring element, thus opening a fluid path for rapid fluid dissipation, bypassing at least one or all of the separator grids. After the overpressure has dissipated, the base body can again seal against the housing, thereby restoring the housing's seal.

[0026] In some embodiments, the base body can have at least one force application area where the spring element can be applied to transmit a preload force, the force application area preferably being formed in the form of a radial projection or indentation of the base body.

[0027] According to a favorable design of the venting separator, the first separator grid can be designed for separating coarse particles and the second separator grid for separating fine particles. In this way, the larger particles can be advantageously filtered out of the fluid stream by the first separator grid. The smaller particles that still pass through can be separated by the second separator grid, so that only the smallest particles can escape into the outside.

[0028] In an advantageous further development, a medium for depth filtration of particles can be arranged between the first separation grid and the second separation grid.

[0029] In a depth filter, particle separation occurs at depth within the filter medium. Unlike a surface filter, the formation of a filter cake is expressly undesirable in depth filtration. A depth filtration medium, unlike a surface filter, does not operate according to the "sieving effect" but is based on a combination of the separation mechanisms interception, sedimentation, and diffusion.

[0030] The advantages of using a depth filter are explained in more detail below.

[0031] The explosion of battery cells produces particles of varying sizes. Electrode materials release particles ranging in size from 5 to 50 µm. Even finer are soot particles, which are generated, for example, by the burning of the battery cell separator. Melting metallic components such as current collectors forms particles ranging in size from 100 to 1,000 µm. Fragments of cell casings, for example, are in the millimeter range. Separating this broad particle size spectrum presents a significant process engineering challenge, as a sharp increase in pressure drop must be avoided during the separation process to ensure the desired gas release from the battery casing. If purely surface filters, such as sieve structures, are used, the mesh size must be very small, which can lead to rapid clogging.Porous depth filters, on the other hand, also separate smaller particles at fiber structures deep within the filter medium, with the pressure drop increasing only gradually. However, such structures can easily become blocked by large particles at the surface. Therefore, a multi-stage filtration cascade is advisable, with a surface filter initially separating the larger particles, followed by the smaller particles being separated in the depth filter. Adding a downstream filter stage for fine filtration is advantageous.

[0032] According to a favorable embodiment of the venting separator, the depth filter can comprise a nonwoven fabric, in particular a metal fiber nonwoven, and / or a foam, in particular a metal foam. With nonwovens, particle separation can occur through the fibers of the nonwoven. With foams, particle separation can occur via ribs in the material. Such a three-dimensional structure of the depth filter allows for the reliable separation of particles that exhibit a comparatively large longitudinal extent despite a small transverse diameter.

[0033] According to a favorable embodiment of the venting separator, the depth filter can be multi-stage, with a first stage for separating large particles, particularly those at least 1 mm in size, and a second stage downstream of the venting flow for separating small particles, particularly those at least 0.1 mm in size. The depth filter can thus be made of several nonwovens or sponges. In this way, particles can be absorbed in the depth filter like in a sponge, reducing the risk of separated particles clogging the venting fluid flow path. This effectively prevents the venting separator from becoming clogged and thus avoids the inability to quickly dissipate any built-up overpressure, which could lead to damage to the housing.

[0034] According to a favorable design of the venting separator device, the inflow area of ​​the depth filter can be at least 15% larger than the geometric cross-section of a venting opening in the housing. This allows the separation effect of the depth filter to be utilized effectively while still ensuring rapid pressure relief of the overpressure in the housing.

[0035] According to a favorable design of the venting separator, the depth filter can exhibit a density gradient along a flow direction. Such a three-dimensional structure of the depth filter allows for the reliable separation of particles that have a comparatively large longitudinal extent despite a small transverse diameter.

[0036] Alternatively or additionally, at least two preferably metallic media suitable for depth filtration with different density gradients can be arranged to flow serially between the separation grids.

[0037] According to a favorable embodiment of the venting separator device, the outlet opening can be located in the side wall of the base body and / or in an end face of the base body facing the environment. In this way, the exiting gas flow can be deflected by 90° so that it does not strike a component located directly next to the housing. Where possible, the gas flow can alternatively be discharged directly via the end face of the base body. This may result in lower flow resistance in the gas flow.

[0038] Advantageously, the base body can be designed to be installed at least partially outside the housing. This allows the venting and separating device to be located at least partially outside the housing, thus saving space inside the housing, for example, for accommodating battery cells.

[0039] According to a favorable embodiment of the venting separator device, the base body and / or the first separator grid and / or the second separator grid can be made of a heat-resistant material, in particular a heat-resistant plastic or metal, especially sheet steel. In particular, the first and / or the second separator grid can be made of metal. Since the gas escaping from battery cells can be very hot, typically exceeding 200°C, it is advantageous to use particularly heat-resistant materials such as metals, especially sheet steel, for the separator grids.

[0040] According to a favorable design of the venting separator, the first separator grid can be arranged to extend across a cross-section of the base body. This ensures that the entire outgoing gas flow is filtered by the first separator grid. Alternatively or additionally, the outlet opening can be designed as a second separator grid. In this way, space inside the base body can be saved for accommodating the second separator grid. The venting separator can therefore occupy a smaller installation space.

[0041] According to a favorable embodiment of the venting separator, the direction of the vent flow can be deflected from the inlet opening to the outlet opening, in particular by 90°. This ensures that there is no direct access to the interior of the housing via the venting separator. This can be advantageous as splash protection, for example, when using steam cleaners for cleaning.

[0042] According to a favorable embodiment of the venting and separating device, the second separating grid can be arranged within the base body, and in particular, covered by the base body. In this way, it is possible to selectively influence the flow direction and, for example, advantageously to redirect the exiting gas stream.

[0043] According to a favorable embodiment of the venting separator device, the second separator grid can have a swirl-reducing or swirl-preventing design. In particular, a surface of the second separator grid can be inclined towards the outlet opening. By selectively deflecting the exiting gas flow inside the base body, a swirl-reducing or even swirl-preventing effect can be exerted on the gas flow. This advantageously reduces pressure loss when the gas flow exits into the environment, thus enabling a faster reduction of overpressure.

[0044] According to a favorable embodiment of the venting separator device, the second separator grid can have at least one projection arranged upstream of the outlet opening in the direction of the venting flow. In particular, the projection can extend parallel to the outlet opening. Specifically, the grid openings of the second separator grid are located on the side of the projection facing away from the outlet opening. This ensures that the separator grids cannot be accessed and thus damaged from the outside using a wire or wire-like tool. The separator grids are also protected from direct impact by water jets, for example, from a high-pressure cleaner.

[0045] According to a further aspect of the invention, a housing, in particular a battery housing, especially of a traction battery of a motor vehicle, for receiving battery cells is proposed, which has at least one housing wall with at least one housing opening, wherein the housing opening is closed by a venting separator device according to the invention, in particular on an outside of the housing wall.

[0046] The proposed housing, which can be used particularly as a battery housing, features a venting and separating device for removing particles above a certain size from hot gas streams, which can typically exceed 200 °C. The actual outgoing fluid flow is not further obstructed, so the pressure drop does not increase unacceptably due to the particles deposited by the filter. The venting and separating device can advantageously have a particularly flat design, thus providing sufficient installation space for battery cells and / or electronics within the housing.

[0047] The venting separator device can be located, for example, inside the housing, but also outside the housing or at least partially outside the housing.

[0048] The venting and separating device includes a pressure relief valve, which allows any overpressure that occurs in the event of a fault to be quickly relieved in order to prevent damage to the housing. For example, this could be a housing for lithium-ion batteries, where gases released in the event of a cell defect must be vented from the housing very quickly. Often, however, it is necessary to prevent the particles released with the gases during a fault from escaping into the environment.

[0049] In this way, it is possible to integrate a housing, such as a battery housing, with a very cost-effective and efficient venting and separation device for particles. The size distribution, quantity, and / or weight of the particles can be adjusted to the requirements by selecting appropriate separators and dimensions, such as surface area, length, and diameter, and the pressure drop in the system can be optimized. Furthermore, the venting and separation device can be easily mounted externally onto the battery housing and offers the possibility of integrating additional features, such as a rupture disc, permanent pressure equalization, and a bypass in case the separator grids become clogged.

[0050] According to a favorable housing design, the venting and separating device can be located at least partially outside the housing. This allows the venting and separating device to be located at least partially inside the housing, thus saving space within the housing, for example, for housing battery cells and / or battery electronics.

[0051] According to a favorable embodiment of the housing, the housing opening can be closed by a membrane stretched across a flat surface, wherein the membrane is fluid-tightly connected to the housing opening.

[0052] The membrane, which can advantageously be designed as a semipermeable membrane, allows the passage of gaseous media from an environment into the electronic housing and vice versa, but prevents the passage of liquid media and solids.

[0053] Any material that exhibits sufficient gas permeability for ventilation during normal operation and adequate water impermeability can be used for the semipermeable membrane. Polytetrafluoroethylene (PTFE) is a preferred material for the semipermeable membrane. The semipermeable membrane has an average pore size that can range from 0.01 micrometers to 20 micrometers. The porosity is preferably around 50%; the mean pore size is preferably about 10 micrometers.

[0054] The semipermeable membrane can preferably be designed as a thin, film-like, foil-shaped, or disc-shaped membrane. The gas-permeable membrane has a membrane surface effective for gas permeation, which preferably has a rectangular or round outer contour. However, it is understood that the outer circumference of the membrane can also be designed differently. The membrane is preferably a thin, flat membrane whose surfaces, effective for gas permeation and facing away from each other, are essentially parallel to each other and preferably essentially planar.

[0055] The membrane thickness is significantly smaller than its other external dimensions. The membrane can span a minimum width and / or length or a minimum outer diameter of 20 mm or greater, preferably 30 mm or greater, and in particular 40 mm or greater. The membrane thickness can be at least 20 times, preferably at least 40 times, and in particular at least 100 times smaller than the minimum width and / or length or the minimum outer diameter of the membrane. The membrane thickness can range from 1 micrometer to 5 millimeters, with a membrane thickness of 0.1 to 2 mm, and in particular 0.15 to 0.5 mm, being preferred.

[0056] Furthermore, the membrane can be connected around its perimeter to the edge of a gas passage opening of a base body, in particular a degassing unit, especially by welding, preferably on an inner side of the base body. Alternatively, the membrane can also be bonded or held in place by friction, for example by clamping. The porous PTFE membrane materials described herein as preferred can be easily welded to a plastic base body or otherwise bonded in a material-bonded manner.

[0057] In the event of a sudden increase in pressure inside the housing, for example due to a defective battery cell, the membrane can be weakened in a targeted manner, for example via an emergency degassing pin, causing it to rupture so that the hot gas from the battery cell can escape from the housing. Brief description of the drawings

[0058] Further advantages will become apparent from the following description of the drawings. The drawings illustrate embodiments of the invention as well as embodiments not covered by the main claim. The drawings, the description, and the claims contain numerous features in combination. It will be advantageous for a person skilled in the art to also consider the features individually and combine them into meaningful further combinations.

[0059] They show, for example: Fig. 1 an isometric section of a venting separator device according to an embodiment of the invention; Fig. 2 a longitudinal section through the venting separator device according to Fig. 1 with section planes AA and BB shown; Fig. 3 a cross-section through the venting separator device according to Fig. 1 along the cutting plane BB; Fig. 4 a cross-section through the venting separator device according to Fig. 1 along the cutting plane AA; Fig. 5 an isometric representation of the venting separator device according to Fig. 1 with closed pressure relief valve; Fig. 6 an isometric representation of the venting separator device according to Fig. 1 with open pressure relief valve; Fig. 7 an isometric section of a venting separator device according to a non-inventive embodiment of the invention; Fig. 8 a longitudinal section through the venting separator device according to Fig. 7 with section planes AA and BB shown; Fig. 9 a cross-section through the venting separator device along the cutting plane BB to Fig. 8; Fig. 10 a cross-section through the venting separator device along the cutting plane AA to Fig. 8; Fig. 11 an isometric representation of the venting separator device according to Fig. 7 with closed pressure relief valves; Fig. 12 an isometric representation of the venting separator device according to Fig. 7 with open pressure relief valves; Fig. 13 an isometric representation of a venting separator device according to a further non-inventive embodiment of the invention; Fig. 14 an isometric section through the venting separator device according to Fig. 13; Fig. 15 a longitudinal section through the venting separator device according to Fig. 13 with section plane AA drawn in; Fig. 16 a cross-section through the venting separator device along the cutting plane AA to Fig. 15; Fig. 17 a further longitudinal section through the venting separator device to Fig. 13 with section plane CC drawn in; Fig. 18 a longitudinal section through the venting separator device along the section plane CC according to Fig. 17; Fig. 19 an isometric representation of the venting separator device according to Fig. 13 with the pressure relief valve open; Fig. 20 an isometric representation of a venting separator device according to a further non-inventive embodiment of the invention; Fig. 21 a longitudinal section through the venting separator device according to Fig. 20 with section planes AA and BB shown; Fig. 22 a further longitudinal section through the venting separator device to Fig. 20 with section plane CC drawn in; Fig. 23 a cross-section through the venting separator device along the cutting plane AA to Fig. 21; Fig. 24 a cross-section through the venting separator device along the cutting plane BB according to Fig. 21; Fig. 25 a longitudinal section through the venting separator device along the section plane CC according to Fig. 22; and Fig. 26 an isometric representation of the venting separator device according to Fig. 20 with open pressure relief valves. Embodiments of the invention

[0060] In the figures, identical or similar components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0061] Fig. Figure 1 shows an isometric section of a venting separator device 100 according to an embodiment of the invention, while in Fig. 2 a longitudinal section through the venting separator device 100 with section planes AA and BB shown.

[0062] The venting and separating device 100, in particular a venting filter, for a degassing unit of a housing 50 comprises a base body 10 with a circumferential rim 12, which is provided for coupling to the housing 50. Only the part of the housing 50 on which the venting and separating device 100 is arranged is shown.

[0063] The housing 50, in particular a battery housing, especially of a traction battery for a motor vehicle, serves to hold battery cells. The housing 50 has a housing wall 54 with at least one housing opening 52. The housing opening 52 is covered by the venting separator device 100 on the outside 56 of the housing wall 54.

[0064] The venting and separating device 100 is arranged outside the housing 50. In an alternative embodiment, however, the venting and separating device 100 could also be installed, wholly or at least partially, inside the housing 50.

[0065] The cylindrical base body 10 has an inlet opening 14, which covers the entire cross-sectional area of ​​the base body 10, and an outlet opening 18. When properly mounted on the housing 50, one inlet opening 14 is in fluid communication with the interior 58 of the housing 50 via the housing opening 52, while the other outlet opening 18 is in fluid communication with the surroundings 80. The outlet opening 18 is located in the end face 16 of the base body 10 facing the surroundings 80.

[0066] The base body 10 has, in a venting flow direction 24, which is indicated by an arrow, a first separating grid 20 with first grid openings 22 extending downstream of the fluid flow and encompassing the inlet opening 14. Downstream of the first separating grid 20 and encompassing the outlet opening 18, the base body 10 has a second separating grid 30 with second grid openings 32. The outflowing gas thus flows through both separating grids 20 and 30 in series.

[0067] The first separator grid 20 is designed for separating coarse particles and the second separator grid 30 for separating fine particles. The first separator grid 20 extends across a cross-section of the base body 10, while the outlet opening 18 forms the second separator grid 30.

[0068] The base body 10 and / or the first separator grid 20 and / or the second separator grid 30 can advantageously be made of a heat-resistant material, in particular a heat-resistant plastic or metal, in particular sheet steel. In particular, the first and the second separator grids 20, 30 can be made of metal, since the gases escaping in the event of a cell defect can reach very high temperatures, for example 200°C and more.

[0069] The housing opening 52 is closed by a membrane 60 stretched across its surface. The membrane 60 is preferably designed as a semipermeable membrane and is fluid-tightly connected to the housing opening 52. In the figures shown here, the membrane 60 is depicted with a gas flow opening 28. This condition occurs when such a high overpressure has built up in the interior 58 of the housing 50 that the membrane 60 has either ruptured spontaneously or has been weakened to such an extent that it ruptures, for example by means of an emergency degassing mandrel (not shown).

[0070] A pressure relief valve 40 is provided in the venting and separating device 100, which, when overpressure occurs in the housing 50, opens a bypass fluid flow path 26 from the interior 58 of the housing 50 to the environment 80, wherein the bypass fluid flow path 26 is arranged upstream of at least one of the separating grids 20, 30. The pressure relief valve 40 is formed by the fact that, when properly assembled, the base body 10 is pressed against the housing 50 in a substantially fluid-tight manner by means of three pre-tensioned spring elements 42. The spring elements 42, designed as helical compression springs, are pre-tensioned against the housing 50 by means of fastening screws 48 and thus press the base body 10 against the outer surface 56 of the housing 50 in a substantially fluid-tight manner over the rim 12 during normal operation.

[0071] Fig. Figure 3 shows a cross-section through the venting separator device 100 according to Fig. 1 along the cutting plane BB to Fig. 2, while Fig. 4 a cross-section through the venting separator device 100 along the cutting plane AA according to Fig. 2 represents.

[0072] In the sections shown, the second separating grid 30 is shown in the top view ( Fig. 3) or the first separator grid 20 ( Fig. 4) can be seen. The first separating grid 20 is designed for coarse particle separation and has circular grid openings 22, while the second separating grid 30 is designed for fine particle separation and has slot-shaped grid openings 32. The first separating grid 20 can, for example, separate particles with a diameter of less than 1.5 mm, while the second separating grid 30, for example, separates particles with a diameter of less than 1.0 mm.

[0073] In Fig. 4 The three fastening screws 48 arranged on the circumference of the cylindrical venting separator device 100 with the spring elements 42 arranged around them can also be seen as a pressure relief valve 40.

[0074] Fig. Figure 5 shows an isometric representation of the venting separator device 100 according to Fig. 1 with closed overpressure valve 40, wherein the base body 10 with the edge 12 is essentially fluid-tight against the outside 56 of the housing 50.

[0075] In Fig. Figure 6 shows the venting and separating device 100 with the pressure relief valve 40 open. The edge 12 of the base body 10 is lifted from the outer surface 56 of the housing 50. The spring element 42 of the pressure relief valve 40 is compressed by the overpressure generated in the interior 58 of the housing 50. This opens the fluid path 26, indicated by the arrow, and the gas produced can escape to the surroundings 80.

[0076] Fig. Figure 7 shows an isometric section of a venting / separation device 100 according to a non-inventive embodiment, while in Fig. Figure 8 shows a longitudinal section through the venting separator device 100 with section planes AA and BB shown.

[0077] In this embodiment, the rectangular base body 10 has a total of four outlet openings 18 on its end face 16, namely two adjacent rectangular and two adjacent circular outlet openings 18. These outlet openings 18 are also designed as second separator grids 30. The first separator grid 20, as in the previous embodiment, extends over the entire cross-sectional area of ​​the inlet opening 14 of the base body 10.

[0078] The base body 10 is mounted to the rim 12 on the outside 56 of the housing 50 in a substantially fluid-tight manner via mounting tabs and mounting screws 48. As shown in Fig. As can be seen in Figure 7, the housing 50 has two adjacent housing openings 52, above which the venting and separating device 100 is arranged in a substantially fluid-tight manner. The two housing openings 52 are each covered with membranes 60, which already have a gas flow opening 28.

[0079] This venting and separating device 100 has a different type of pressure relief valve 40. The pressure relief valves 40 are formed by the base body 10 having one or more predetermined deformation points 44. The predetermined deformation point 44 is designed as a flap 46 that pivots outwards towards the environment 80. The flap 46 has two spaced-apart slots 45 in the side walls 11, between which a predetermined deformation area 43 extends, acting as a hinge for the flap 46. The slots 45 and / or the predetermined deformation area 43 can be provided in the form of perforations in the base body, these perforations opening under overpressure and allowing the flap 46 to pivot outwards.

[0080] The predetermined deformation area 43, which acts as a hinge for the flap 46, has a hinge slot interrupted by a plurality of webs that connect the flap body to the base body. The actuation pressure of the overpressure valve 40 thus designed can be significantly influenced by the geometry and material properties of these webs.

[0081] Through the resulting openings, the gas can escape from the interior 58 of the housing 50 into the surrounding environment 80. Once open, the flaps 46 cannot be closed again. This is a significant difference from the pressure relief valves 40, which are represented by a spring element 42 and close again when the pressure in the interior 58 of the housing 50 decreases.

[0082] Fig. Figure 9 shows a cross-section through the venting separator device 100 along the section plane BB. Fig. 8 with a top view of the second separator grid 30, while Fig. 10 a cross-section through the venting separator device 100 along the cutting plane AA according to Fig. Figure 8 shows a top view of the first separation grid.

[0083] The second separating grids 30 are again designed with slot-shaped grid openings 32, while the first separating grid 20 is designed with circular grid openings 22.

[0084] In Fig. Figure 11 shows the venting separator device 100 with closed pressure relief valves 40, while in Fig. Figure 12 shows the venting separator device 100 with open pressure relief valves 40.

[0085] The two longer side walls 11 of the base body 10 each have two flaps 46, while the two shorter side walls 11 each have only one flap 46. Fig. Figure 12 shows how the flaps 46 open outwards towards the surroundings 80, each opening providing a pathway for the fluid path 26. For clarity, only one arrow is shown as the fluid path 26. The gas naturally flows out through the other flaps 46 in the same way.

[0086] Fig. Figure 13 shows an isometric representation of a venting separator device 100 according to a further embodiment not according to the invention. Fig. Figure 14 shows an isometric section through the venting separator device 100, while in Fig. Figure 15 shows a longitudinal section through the venting separator device 100 with the section plane AA drawn in.

[0087] The rectangular base body 10 is mounted to the outer surface 56 of the housing 50 in a substantially fluid-tight manner via mounting tabs and mounting screws 48 at the rim 12. As shown in Fig. As can be seen in Figure 14, the housing 50 has two adjacent housing openings 52, over which the venting and separating device 100 is arranged in a substantially fluid-tight manner. The two housing openings 52 are each covered with membranes 60, which already have a gas flow opening 28.

[0088] In this embodiment, the venting flow direction 24 is deflected by 90° from the inlet opening 14 to the outlet opening 18, i.e., the gas flows out towards the side of the base body 10. The base body 10 has an outlet opening 18 in a side wall 11, which is designed as a second separator grid 30.

[0089] The first separating grid 20 is arranged inside the base body 10 and is designed with a slope descending towards the outlet opening 18.

[0090] Fig. Figure 16 shows a cross-section through the venting separator device along the section plane AA. Fig. 15, showing a top view of the first separating grid 20 with circular grid openings 22.

[0091] The sloping incline of the first separator grid 20 is particularly evident in Fig. Figure 17 shows a further longitudinal section through the venting separator device 100 with the section plane CC indicated. The direction of the venting flow 24 towards the side of the base body 10 is also shown as an arrow.

[0092] Fig. Figure 18 shows a longitudinal section through the venting separator device 100 along the section plane CC. Fig. 17. The outlet opening 18 with slot-shaped grid openings 32 is visible together with the first separating grid 20 arranged below it.

[0093] The in the Fig. 13, Fig. 14, Fig. 15, Fig. 16, Fig. 17, Fig. 18 to Fig. The embodiment shown in 19 has, as in the previous embodiment, pressure relief valves 40 formed as flaps 46 in the side walls. Fig. Figure 13 shows the venting separator device with closed pressure relief valve 40. Fig. Figure 19 shows the venting separator device 100. Fig. 13 with open pressure relief valve 40 and bypass fluid flow path 26 shown. The pressure relief valve 40 located on the opposite side wall 11 is not visible in the illustration.

[0094] Fig. Figure 20 shows an isometric representation of a venting separator device 100 according to a further non-inventive embodiment, while in Fig. Figure 21 shows a longitudinal section through the venting separator device 100 with section planes AA and BB shown. Fig. Figure 22 shows another longitudinal section through the venting separator device 100 with the section plane CC indicated.

[0095] The rectangular base body 10 is mounted to the outer surface 56 of the housing 50 in a substantially fluid-tight manner via mounting tabs and mounting screws 48 at the rim 12. As shown in Fig. As can be seen in Figure 22, the housing 50 has two adjacent housing openings 52, over which the venting and separating device 100 is arranged in a substantially fluid-tight manner. The two housing openings 52 are each covered with membranes 60, which already have a gas flow opening 28.

[0096] In this embodiment, outlet openings 18 are arranged in opposing side walls 11 of the base body 10. These outlet openings 18 are not designed as secondary separating grids, but serve only as openings for the escaping gas. The direction of the venting flow 24 is indicated by arrows.

[0097] The second separator grid 30 is located within the base body 10 and is, in particular, covered by the base body 10. The second separator grid 30 has a design specifically for the protection of the separator grids. Specifically, a surface 34 is inclined towards the outlet opening 18 in the direction of the vent flow 24 in front of the outlet opening 18. The protrusions 36 extend parallel to the outlet opening 18. This prevents direct access to the separator grids, even with a wire-like tool, and also prevents direct contact with a water jet, for example, from a high-pressure cleaner.In this embodiment, the grid openings of the second separating grid 30 are located on one side of the protrusion 36 facing away from the outlet opening 18, which means a further improved protective function against mechanical damage for the first separating grid 20,30.

[0098] The first separating grid 20 is arranged with circular grid openings 22 as in the previous embodiments such that it covers the entire cross-sectional area of ​​the inlet opening 14 of the base body 10.

[0099] Fig. Figure 23 shows a cross-section through the venting separator device 100 along the section plane AA. Fig. 21 a top view of the first separation grid 20 with circular grid openings 22.

[0100] Fig. Figure 24 shows a cross-section through the venting separator device 100 along the section plane BB. Fig. 21 with a top view of the second separating grid 30, which has slot-shaped grid openings 32.

[0101] Fig. Figure 25 shows a longitudinal section through the venting separator device 100 along the section plane CC. Fig. 22, in which the first and second separating grids 20, 30 and above them an outlet opening 18 are visible.

[0102] The in the Fig. 20, Fig. 21, Fig. 22, Fig. 23, Fig. 24, Fig. 25 to Fig. The embodiment shown in 26, which is not according to the invention, has pressure relief valves 40 formed as flaps 46 in the side walls, as in the previous embodiment. Fig. Figure 20 shows the venting separator device 100 with closed pressure relief valves 40.

[0103] In Fig.Figure 26 shows the venting and separating device 100 with open pressure relief valves 40, which open outwards as flaps 46 arranged on opposite side walls 11. The bypass fluid flow path e 26 of the escaping gas is shown with arrows. Reference symbol: 10 basic shapes 11 Side wall 12 Rand 14 Entrance opening 16 Front 18 Outlet opening 20 first separator grid 22 first grid opening 24 Venting flow direction 26 Bypass fluid flow path 28 Gas flow opening 30 second separator grid 32 second grid opening 34 area 36 Survey 40 Overpressure valve 42 Spring element 43 Target deformation range 44 Target deformation point 45 slots 46 flap 48 fastening screw 50 cases 52 Case opening 54 Housing wall 56 Outside 58 Interior 60 Membran 70 Axial direction 72 Radial direction 80 surroundings 100 Venting separator device

Claims

[1] Venting separator device (100) for a housing (50) of a battery, in particular a traction battery of a motor vehicle, comprising a base body (10) with a circumferential rim (12) which is intended for coupling to the housing (50), wherein the base body (10) has at least one inlet opening (14) and at least one outlet opening (18), wherein the at least one inlet opening (14) can be brought into fluid contact with an interior (58) of the housing (50) when mounted as intended, and the at least one outlet opening (18) is in fluid contact with an environment (80), wherein the base body (10) has at least one first separating grid (20) with first grid openings (22) extending over the inlet opening (14) and, in a venting flow direction (24) downstream of the first separating grid (20) extending over the outlet opening (18), has a second separating grid (30) with second grid openings (32), wherein the venting separator device (100) has at least one overpressure valve (40) which is configured to open a bypass fluid flow path (26) from the interior (58) of the housing (50) to the environment (80) when a predetermined overpressure in the housing (50) is exceeded, wherein the bypass fluid flow path (26) bypasses at least one of the separator grids (20, 30), and wherein the pressure relief valve (40) is formed by the fact that the base body (10) in an assembly state can be pressed against the housing (50) in a sealing manner via at least one pre-tensioned spring element (42), wherein, when the predetermined overpressure in the housing (50) is exceeded, the base body (10) can be lifted off the housing (50) against the pre-tensioned spring element (42) by opening the bypass fluid flow path (26). [2] Venting separator device according to claim 1, wherein the bypass fluid flow path (26) bypasses both separator grids (20, 30). [3] Venting separator device according to claim 1 or 2, wherein the base body (10) has at least one force application area on which the spring element (42) can be applied to transmit a preload force, wherein the force application area is preferably formed in the form of a radial projection or indentation of the base body (10). [4] Venting separator device according to one of the preceding claims, wherein the first separator grid (20) is provided for separating coarse particles and the second separator grid (30) is provided for separating fine particles. [5] Venting separator device according to one of the preceding claims, wherein a medium for depth filtration of particles is arranged between the first separator grid (20) and the second separator grid (30). [6] Venting and separating device according to claim 5, wherein the medium for depth filtration has a density gradient, so that increasingly smaller particles can preferably be separated in the venting flow direction (24). [7] Venting separator device according to one of the preceding claims, wherein the outlet opening (18) is arranged in a side wall (11) of the base body (10) and / or in an end face (16) of the base body (10) facing the environment (80). [8] Venting separator device according to one of the preceding claims, wherein the base body (10) and / or the first separator grid (20) and / or the second separator grid (30) are made of a heat-resistant material, in particular of a heat-resistant plastic or of metal, in particular sheet steel, in particular wherein the first and / or the second separator grid (20, 30) are made of metal. [9] Venting separator device according to one of the preceding claims, wherein the venting flow direction (24) is deflected from the inlet opening (14) to the outlet opening (18), in particular by 90°. [10] Venting separator device according to one of the preceding claims, wherein the first separator grid (20) is arranged extending over a cross-section of the base body (10) and / or wherein the outlet opening (18) is designed as a second separator grid (30). [11] Venting separator device according to one of claims 1 to 9, wherein the second separator grid (30) is arranged inside the base body (10), in particular is covered by the base body (10). [12] Venting separator device according to claim 11, wherein the second separator grid (30) has a swirl-reducing or swirl-avoiding design, in particular wherein a surface (34) of the second separator grid (30) is inclined towards the outlet opening (18). [13] Venting separator device according to claim 12, wherein the second separator grid (30) has at least one protrusion (36) arranged in the venting flow direction (24) in front of the outlet opening (18), in particular wherein the protrusion (36) extends parallel to the outlet opening (18). [14] Housing (50) of a battery, in particular a traction battery of a motor vehicle, for receiving battery cells, which has at least one housing wall (54) with at least one housing opening (52), wherein the housing opening (52) is closed by a venting separator device (100) according to one of the preceding claims, in particular on an outside (56) of the housing wall (54). [15] Housing according to claim 14, wherein the venting separator device (100) is arranged at least partially outside the housing (50). [16] Housing according to claim 14 or 15, wherein the housing opening (52) is closed by a planar membrane (60), wherein the membrane (60) is fluid-tightly connected to the housing opening (52).

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