Degassing channel arrangement for a motor vehicle and motor vehicle
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- AUDI AG
- Filing Date
- 2024-04-17
- Publication Date
- 2026-07-16
AI Technical Summary
Conventional degassing duct arrangements in battery cells are prone to deformation and blockage due to high pressures during thermal events, leading to potential damage and leakage, and require complex support structures that increase production and assembly effort.
A degassing duct arrangement with a supporting structure that contacts only one of the two degassing duct walls, allowing for tolerance compensation and preventing deformation while ensuring reliable gas discharge, using a gap to reduce the risk of intrusion and assembly complexity.
The solution enhances the reliability of gas discharge by preventing duct wall deformation and assembly complexity, while minimizing the risk of battery module damage and noise from vibrations, and allows for efficient tolerance compensation.
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Abstract
Description
[0001] The invention relates to a degassing channel arrangement for a motor vehicle, wherein the degassing channel arrangement comprises a battery module with at least one battery cell, the cell having a first cell side with a releasable cell degassing opening arranged on the first cell side. The degassing channel arrangement further comprises a first degassing channel wall opposite the first cell side, which includes a passage area opposite the releasable cell degassing opening, and a second degassing channel wall opposite the first degassing channel wall on one side facing away from the battery module, with a space between the first degassing channel wall and the second degassing channel wall. The invention further relates to a motor vehicle with such a degassing channel arrangement.
[0002] If a battery cell experiences thermal runaway, the pressure building up inside the cell can be released through a vented cell outlet. This outlet can be, for example, a rupture membrane within the cell casing. In automotive applications, the gases escaping from such a battery cell during thermal runaway can often be vented, particularly from the vehicle, via a degassing channel, which may also be in the form of a chamber or similar structure. The battery cells can be arranged on a first degassing channel wall with their vented cell outlets facing it. The degassing channel wall includes a passage through which the gases escaping from the runaway cell can pass into the space between the first degassing channel wall and the second, opposing degassing channel wall.The degassing channel can be formed by the two degassing channel walls and the space between them. Gas can flow through this space to a designated outlet opening. Furthermore, battery cells in a motor vehicle can be arranged with their respective cell degassing openings facing downwards. Accordingly, such a second degassing channel wall could, for example, be the vehicle's underride guard. In this case, it should be ensured as reliably as possible that external forces, especially those acting from below on the underride guard, cannot damage the battery cells located above it.
[0003] EP 4 207 438 A1 describes a battery with multiple battery cells, which may have removable degassing vents, a temperature control plate on which the cells are arranged, and a cavity located below the temperature control plate for collecting gases. The space between the temperature control plate and a base plate may be located there. A support element may also be located in this space to increase its pressure resistance. This support element can take various forms, for example, a honeycomb structure distributed throughout the space.
[0004] The object of the present invention is to provide a degassing channel arrangement and a motor vehicle that enable the most unhindered and reliable removal possible of gases escaping from a thermally continuous battery cell via a degassing channel.
[0005] This problem is solved by a degassing channel arrangement and a motor vehicle with the features according to the respective independent patent claims. Advantageous embodiments of the invention are the subject of the dependent patent claims, the description, and the figures.
[0006] An inventive degassing channel arrangement comprises a battery module with at least one battery cell, which has a first cell side with a releasable cell degassing opening arranged on the first cell side, a first degassing channel wall opposite the first cell side and which comprises a passage area opposite the releasable cell degassing opening, and a second degassing channel wall opposite the first degassing channel wall on a side facing away from the battery module, wherein there is a space between the first degassing channel wall and the second degassing channel wall.In this arrangement, a support structure is provided in the space between the two degassing channels to support the first degassing channel wall against the second degassing channel wall in the event of gas escaping from the releasable cell degassing opening, wherein the support structure is arranged in contact with one of the two degassing channel walls in an undeformed initial state of the first and second degassing channel walls and does not contact the other of the two degassing channel walls.
[0007] The invention is based on several insights: Firstly, to protect the interior of a battery housing from environmental influences as effectively as possible, it is advantageous to design it in such a way that as little dust, moisture, or similar substances as possible can enter the interior of such a battery housing. Accordingly, it is advantageous to design the passage area in the first degassing channel wall as a predetermined passage area or predetermined breaking point, which is preferably fluid-tight in its undamaged, normal state. If gas escapes from the accessible cell degassing opening of the battery cell, this gas can, so to speak, burn through the passage area of the degassing channel wall and thereby enter the space and thus the degassing channel.However, in this configuration, the degassing channel wall in the area of this passage, which is at least partially closed when the gas initially impacts it, is subjected to very high pressures from the gas escaping from the battery cell. With conventional designs, these pressures can cause the degassing channel wall in the passage area to deform towards the opposite, second degassing channel wall. Furthermore, the space between the two degassing channel walls can be very narrow, so that in the worst case, the first degassing channel wall could even come into contact with the opposite second degassing channel wall. This would block the passage area from the opposite degassing channel wall, and the gas would no longer be able to enter the space, or only with great difficulty.In conventional designs, the escaping cell gas during thermal cell propagation can plastically deform the first degassing channel wall towards the second degassing channel wall, leading to a blockage of the degassing path into the interstitial space. A burn-through of the opening in the first degassing channel wall during such a thermal propagation event would then no longer occur or would be significantly hindered. Furthermore, consequential damage could potentially occur due to leaking adhesive seams forming between the cell module and the cooling module. Therefore, it is highly advantageous to provide a support structure between the two degassing channel walls. To ensure that this support structure is as effective as possible in the described degassing scenario, it is desirable to position it as close as possible to the area of the first degassing channel wall opposite the accessible cell degassing opening.However, there is a significant risk here that an external force applied to the second degassing channel wall in the direction of the first degassing channel wall could damage the battery module above it. Specifically, if such an element were arranged to contact both degassing channel walls and thus connect them, in order to brace them against each other, an external force applied to the second degassing channel wall in the direction of the first would cause this element to directly intrude upon the battery module above it. This risk can now be advantageously reduced considerably by having the support structure only contact one of the two degassing channel walls and maintaining a gap from the other, i.e., not contacting it. Thus, a certain gap exists between the support structure and this other degassing channel wall.The gap height does not need to be constant. This gap not only reduces the risk of damage to the battery module but also offers other significant advantages: Firstly, it can simultaneously be used to compensate for tolerances. Automotive batteries, especially high-voltage batteries, are very large and can extend, for example, 1.7 m or more along the vehicle's length. In the vehicle's transverse direction, the battery can extend across the entire area between the two side sills. With regard to the preferred installation position in a vehicle, the first and second degassing channel walls are preferably located below the battery in the vehicle's vertical direction and also extend, for example, across the entire surface of the battery in both the longitudinal and transverse directions.Providing a gap between the support structure and one of the two degassing channel walls significantly simplifies the arrangement of these components relative to each other, while compensating for certain component tolerances, particularly across the aforementioned longitudinal and transverse dimensions. Joining or contacting the support structure to both degassing channel walls would dramatically increase manufacturing and assembly costs. Conversely, joining the support structure to only one of the two degassing channel walls without providing a gap would, in turn, lead to rattling noises due to vibrations, for example, during driving.Thus, the reliability of gas removal during degassing can be significantly increased by the support structure, which is only located on one of the two degassing channel walls and does not contact the other, without increasing the risk of intrusion or damage to the battery module. At the same time, this compensates for component and manufacturing tolerances and prevents rattling noises.
[0008] The two degassing channel walls and the space between them can form a degassing channel within the degassing channel assembly, or at least a portion thereof. Gas entering the space during cell degassing can flow within the space, for example, to a designated outlet opening, and be discharged from there, particularly from the vehicle. The degassing channel, or the space with its degassing channel walls, can also be designed as a chamber, especially a large chamber, for example, with dimensions as mentioned above. Furthermore, battery cells in a vehicle can be arranged with their respective cell degassing openings facing downwards. Accordingly, such a second degassing channel wall could, for example, serve as an underride guard for the vehicle.
[0009] The battery cell can be, for example, a prismatic, pouch, or cylindrical cell. In particular, the battery module can also comprise multiple battery cells. Furthermore, the degassing channel arrangement can include a battery with multiple battery modules. Each battery module can contain one or more battery cells. The battery can be, for example, a high-voltage battery, especially for a motor vehicle. The battery cells can be, for example, lithium-ion cells. Moreover, all the battery cells can be of the same type. That is, the characteristics described for at least one battery cell, and those described later, can apply analogously to the other optional battery cells. The first cell side of the battery cell represents a specific side of the cell housing of the battery cell.The first cell side faces the first degassing channel wall. In particular, the first cell side can also be positioned directly against the first degassing channel wall, for example, partially attached using a leveling compound, such as a gap filler or thermally conductive adhesive. This further reduces the risk of deformation of the first degassing channel wall towards the second degassing channel wall during degassing.
[0010] The passage area in the first degassing channel wall can be designed as described above. It is designed so that gases exiting the through-wall can pass through it to reach the space between the first degassing channel wall and the second, opposing degassing channel wall. The passage area can be provided in the form of a predetermined breaking point or predetermined passage point that is fluid-tight when closed. For example, the passage area can be designed as a kind of material weakening or similar feature. For example, the passage area can be designed as a recess in the first degassing channel wall covered with a thin film, or something similar.
[0011] A releasable cell vent is understood to be an opening that is closed but can be released, i.e., opened, under certain circumstances. Such a releasable cell vent can therefore have a closed state and an open state, and can transition from the closed state to the open state. This transition need not be reversible. It is possible that no further transition from the open state to the closed state is possible, for example, in the case of a releasable cell vent designed as a rupture diaphragm. The releasable cell vent can also be designed in such a way that a transition from the open state to the closed state is possible, for example, if the releasable cell vent is designed as a pressure relief valve. The releasable cell vent is preferably designed as a rupture diaphragm, rupture element, or similar device.
[0012] The support structure is preferably designed such that the distance to the degassing channel wall, on which the support structure is not located, is at least 1 mm, for example 2 mm, but preferably less than 10 mm, for example less than 5 mm. Even slight deformations of the first degassing channel wall in the direction of the second degassing channel wall can thus be reliably supported by the support structure. If such a deformation occurs, the support structure can contact both degassing channel walls in this deformed state and thus support them against each other. Furthermore, the support structure can be designed to fail above a certain force or pressure threshold in a specific first direction, which, with respect to the preferred installation position in a motor vehicle, can correspond to the vehicle's vertical direction.This ensures that a deformation of the second degassing channel wall in the direction of the first degassing channel wall due to an external force does not lead to an intrusion of the support structure into the battery module.
[0013] Furthermore, it is preferred that the support structure be made of a material that is as temperature-resistant or temperature-stable as possible. In principle, plastics and / or metals can be used as materials for the support structure. For metals, steel or stainless steel are particularly suitable due to their high temperature resistance. However, it is very advantageous if the support structure is made of or incorporates a plastic. In particular, the support structure incorporates or is made of a fire-resistant plastic material, especially a plastic material classified as V0. Such plastics exhibit a flammability rating of UL94, with self-extinguishing in the event of a fire within a maximum of 10 seconds.Such a support structure is particularly suitable for withstanding the high temperatures of gas carried through the space during degassing and reliably supporting the degassing channel walls against each other. In particular, the material from which the support structure is made should exhibit sufficient dimensional stability even at high temperatures. Therefore, the material of the support structure should have the highest possible melting point. Preferably, a plastic is chosen as the material, as it also exhibits low moisture absorption and resistance to various media. This is particularly advantageous in "wet" installation locations, especially between the underride guard of the vehicle, which can provide the second degassing channel wall, and the first degassing channel wall. Furthermore, the material should be selected to offer the best compromise in terms of its stiffness (modulus of elasticity).On the one hand, the support structure should withstand the load from the cooling module, or more generally from the first degassing channel wall, at high temperatures during thermal propagation without collapsing. On the other hand, the collapse of the support structure under an underbody load, i.e., deformation of the second degassing channel wall (e.g., the underride guard) from below towards the vehicle cells (e.g., by bollards or gunfire), is absolutely desirable in order to minimize cell intrusion. The undeformed initial state of the first and second degassing channel walls is the normal state for both walls. In this state, the degassing channel walls are considered undeformed.If these are intact and undamaged, and no gas is escaping from the cell, the support structure only contacts one of the two degassing channel walls and is spaced apart from the other. Contact between the support structure and both degassing channel walls simultaneously only occurs when one of the two degassing channel walls is sufficiently deformed from its undeformed initial state towards the other. This would occur, for example, if the first degassing channel wall is deformed towards the second due to gas escaping from the accessible cell degassing opening.
[0014] In principle, the support structure can be arranged on the first degassing duct wall and at a distance from the second degassing duct wall. Alternatively, the support structure can also be arranged on the second degassing duct wall and at a distance from the first degassing duct wall. It is also conceivable that the degassing duct wall has several support structures arranged at a distribution, one or more of which are located on the first degassing duct wall and one or more on the second degassing duct wall.
[0015] According to a further advantageous embodiment of the invention, the battery module comprises a cell stack with several battery cells arranged side by side in a longitudinal direction, wherein the support structure extends in one or more parts in the space between the cells in the longitudinal direction over several or all of the battery cells of the cell stack. This allows support to be provided by the support structure over the entire length of the battery module. This elongated design of the support structure can, in particular, be implemented in one piece over longer distances in the longitudinal direction, which can also be referred to as the longitudinal extension direction. This reduces assembly effort. For example, the support structure can be a single component, e.g.The injection-molded component extends over the entire length of the battery module in the longitudinal direction, in particular over the entire length or substantially the entire length of the battery that the battery module comprises. This means that only one component needs to be mounted on the corresponding degassing channel wall, unless the corresponding degassing channel wall is already integrally formed with the support structure. For simplified manufacturing, especially with very long battery modules up to 1.70 m in length, the support structure can also be designed in multiple parts. The support structure can thus comprise several support structure elements arranged side by side in the longitudinal direction. These can also each be manufactured as a single component and extend over several centimeters or even tens of centimeters.Therefore, only a few such separate support elements need to be provided as part of the support structure in the longitudinal direction.
[0016] According to a further advantageous embodiment of the invention, the support structure comprises a first longitudinal structural element extending in the longitudinal direction, which has a wave-like, in particular trapezoidal, shape in the longitudinal direction, such that the height of the longitudinal structural element varies in the longitudinal direction relative to the degassing channel wall to which the support structure is arranged in contact. Due to the wave-like shape, in particular the trapezoidal shape, the support structure can be designed to be particularly gas-permeable while still exhibiting very high structural stiffness and stability for supporting the degassing channel walls against each other.
[0017] The longitudinal direction extends parallel to the stacking direction of the aforementioned cell stack. A transverse direction, as explained below, can be defined perpendicular to the longitudinal direction. Furthermore, a vertical direction can be defined perpendicular to both the longitudinal and transverse directions. In this case, the first degassing channel wall is located above the second degassing channel wall with respect to the vertical direction, and the battery module is located above the first degassing channel wall with respect to the vertical direction. With regard to a standard installation position in a motor vehicle, the vertical direction corresponds to the vehicle's vertical direction. The longitudinal direction preferably corresponds to the vehicle's longitudinal direction, and the transverse direction preferably to the vehicle's transverse direction. However, the longitudinal and transverse directions can also be defined in reverse. The term "opposite," which will be used frequently in the following, refers in particular to an opposition with respect to the vertical direction."Opposite" can therefore be understood in the sense of a vertical projection with respect to the vertical direction, that is, in or against the vertical direction. Two areas, elements, or components can also be opposite each other if there are further elements, components, or areas between them. The opposing components or areas do not have to be congruent; they can also only partially overlap or intersect in the aforementioned vertical projection.
[0018] According to a further advantageous embodiment of the invention, the support structure comprises a second longitudinal structure element extending in the longitudinal direction parallel to the first longitudinal structure element, wherein the two longitudinal structure elements are arranged next to each other in a transverse direction, wherein there is an intermediate area between the two longitudinal structure elements which is opposite a cell degassing area of the battery module in which the releasable cell degassing openings of the cells encompassed by the battery module are located.
[0019] Advantageously, two longitudinal structural elements allow the two degassing channel walls to be supported on both sides by the cell degassing area of the battery module located above them. This reliably prevents deformation of the first degassing channel wall during degassing. The second longitudinal structural element can be designed in the same way as described for the first. The longitudinal structural elements can be spaced apart in the transverse direction at least as wide as the respective accessible cell degassing opening of the battery cells enclosed by the battery module.
[0020] The battery module is preferably designed such that the accessible cell degassing openings of the battery cells enclosed by the battery module lie along a longitudinally extending line. The cell degassing area can therefore essentially be understood as a longitudinally elongated rectangular region.
[0021] Furthermore, it is highly advantageous if no structures are arranged in the space opposite this cell degassing area that extend above the height of the support structure in the vertical direction. Preferably, no parts of the support structure itself should be arranged opposite this degassing area either. This provides particularly good protection for the cell degassing area of the battery module.
[0022] According to a further advantageous embodiment of the invention, the support structure comprises at least one transverse structure element extending in the transverse direction and connecting the two longitudinal structure elements, in particular wherein the two longitudinal structure elements and the at least one transverse structure element are designed as a one-piece component, in particular an injection-molded component.
[0023] In principle, such a transverse structural element can also be provided even if it is not formed integrally with the two longitudinal structural elements. The transverse structural element can be positioned in a location described in more detail below, which allows for its design with greater stiffness or robustness. In particular, it can be positioned so that it does not face any cells of the battery module. The transverse structural element can be arranged in the space between, for example, a housing wall of the battery housing, an intermediate wall, a partition wall, a module housing wall, or similar. Even if the transverse structural element is then pressed against the first degassing channel wall by deformation of the second wall, this contact pressure is not transmitted to the battery cells.
[0024] However, especially in the case of a one-piece design of the transverse structure element and the longitudinal structure elements, this transverse structure element has the additional advantage that it allows for a more stable design of the support structure as a one-piece component and a simplified arrangement and assembly.
[0025] For example, several transverse structural elements can be provided, arranged parallel to each other and connecting the two longitudinal structural elements. The longitudinal and transverse structural elements can form a rectangular frame or similar structure. Alternatively, they can form a ladder-like structure. This type of support structure is particularly easy to manufacture using injection molding. Despite its inherently delicate structure, the support structure can be very robust for assembly and facilitates handling. Furthermore, the support structure does not need to be assembled in numerous individual parts on the corresponding degassing channel wall, and in the case of a multi-part design, the individual parts themselves can be larger.
[0026] According to a further advantageous embodiment of the invention, the cell stack is subdivided longitudinally into several cell groups, with a cell group gap located between two of the cell groups, and the transverse structural element arranged in the gap being opposite, and in particular located below, the cell group gap. Thus, as already mentioned above, the transverse structural element is not opposite any battery cells in the vertical direction. This reduces the risk of damage from intrusion. Simultaneously, the transverse structural element can be designed to be significantly more robust and massive. This allows for the stiffening of the geometry of the support element as a whole and enables better support.
[0027] Furthermore, it is preferred that the transverse structural element or the optional additional transverse structural elements are designed, for example, with a through-opening or recesses in the longitudinal direction that allow flow through the transverse structural elements in the longitudinal direction. This prevents the transverse structural elements from blocking a gas discharge path that runs longitudinally between the longitudinal structural elements.
[0028] According to a further advantageous embodiment of the invention, the first degassing channel wall has an underside facing the second degassing channel wall, wherein the underside has a recess in a region opposite the cell group space, directed towards the battery module, and the transverse structural element is arranged in the recess. In the region of the recess, the underside of the first degassing channel wall is thus curved towards the battery module. By arranging the transverse structural element in this recess, it is advantageously possible to make the transverse structural element relatively solid in a region facing the first degassing channel wall without blocking the degassing path described above in the longitudinal direction, since the transverse structural element can be arranged with its region facing the first degassing channel wall elevated.If the transverse structural element is located particularly in the area of this recess, the other components of the support structure are also preferably located on the first degassing channel wall. However, it is also conceivable, for example if the transverse structural elements are designed separately from the longitudinal structural elements, that they are arranged on different degassing channel walls.
[0029] Such a recess can be particularly useful when the first degassing channel wall is designed as a cooling plate and includes integrated cooling channels. These serve to cool the battery cells. In areas where there are no battery cells, such as the space between cell groups, the cooling plate does not need to have cooling channels or a recessed degassing channel area, especially one that is opposite the accessible cell degassing vents and where the cooling plate wall is curved away from the cells to create a gap between them. This allows the cooling plate to have a reduced overall wall thickness in the area below the cell group space, as cooling channels are not required there, and a downward curve can also be omitted.In other words, the top surface of the first degassing channel wall can be flat, while the underside displays the cooling channel structure of the cooling plate, as well as the aforementioned degassing channel area, resulting in unevenness on the underside, which therefore exhibits corresponding ridges and depressions. The transverse structural element can thus be positioned in such a depression.
[0030] However, it is also conceivable that the transverse structural element is positioned opposite the first degassing channel wall on the second degassing channel wall, corresponding to this depression.
[0031] According to a further advantageous embodiment of the invention, the first degassing channel wall is designed as a cooling plate with an integrated cooling channel arrangement comprising cooling channel sections, wherein the cooling plate has a first plate area extending longitudinally, in particular parallel to one of the cooling channel sections, and free of cooling channels, wherein the first longitudinal structural element is opposite or arranged on the first plate area. This is particularly advantageous because the two degassing channel walls can then be supported relative to each other in areas, for example in the case of deformation of the first degassing channel wall towards the second degassing channel wall or of the second degassing channel wall towards the first degassing channel wall, in which no cooling channels are located.Such support therefore does not pose a risk of damaging or deforming the cooling channels, which would reduce the support effect. The support can thus be implemented much more efficiently and reliably. The cooling channel-free area can also be located, in particular, between two longitudinally extending cooling channel sections. Furthermore, the cooling plate preferably also has such a cooling channel-free area in a region opposite the cell degassing area, which was also referred to above as the degassing channel area. A cooling channel-free area of the cooling plate can be directly adjacent to this on both sides, and the longitudinal structural elements can be directly opposite or adjacent to these areas.
[0032] The cooling channels can be designed, in particular, as cavities through which a coolant flows. The arrangement of the cooling channels can also branch out in any number of ways or be of a complex design.
[0033] According to a further advantageous embodiment of the invention, the second degassing channel wall is designed as an underride guard for a motor vehicle. The advantages of the invention and its embodiments are particularly evident when the second degassing channel wall serves as an underride guard. This is because, in the event of degassing, reliable support between the two degassing channel walls can be provided, and the risk of damage to the battery module from external forces acting on the second degassing channel wall is minimized. Such damage is very common when the second degassing channel wall is designed as an underride guard. Therefore, minor forces acting on the underride guard pose no risk of damage to the battery modules.The second degassing duct wall can generally be attached to the first degassing duct wall via additional webs, air-permeable walls, or support components. These attachment points are located, for example, opposite housing components of a battery housing. Thus, a two-sided contact connection and attachment of the second degassing duct wall to the first degassing duct wall via such a support component is possible.
[0034] Furthermore, the invention also relates to a motor vehicle with a degassing channel arrangement according to the invention or one of its embodiments.
[0035] The advantages mentioned for the degassing channel arrangement and its embodiments according to the invention apply equally to the motor vehicle according to the invention.
[0036] The invention also includes further developments of the motor vehicle according to the invention, which have features already described in connection with the further developments of the degassing channel arrangement according to the invention. For this reason, the corresponding further developments of the motor vehicle according to the invention are not described again here.
[0037] The motor vehicle according to the invention is preferably designed as a motor vehicle, in particular as a passenger car or truck, or as a passenger bus or motorcycle.
[0038] The invention also includes combinations of the features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of the features of several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.
[0039] The following are exemplary embodiments of the invention described. This is illustrated by: Fig. 1 a schematic representation of part of a degassing channel arrangement with support structures arranged on a degassing channel wall according to an embodiment of the invention; Fig. 2 a schematic representation of part of a support structure for a degassing channel arrangement according to an embodiment of the invention; Fig. 3 a schematic cross-sectional view of a part of a degassing channel arrangement perpendicular to the transverse direction according to an embodiment of the invention; and Fig. 4 A schematic cross-sectional representation of a part of a degassing channel arrangement perpendicular to the longitudinal direction according to an embodiment of the invention.
[0040] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which can be considered independently of one another and each further develops the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.
[0041] In the figures, identical reference symbols denote functionally equivalent elements.
[0042] Fig. Figure 1 shows a schematic representation of part of a degassing channel arrangement 10 according to an embodiment of the invention. In particular, a degassing channel wall 12 with two support structures 14 arranged on it is shown. The degassing channel wall 12 is designed here as an underride guard 16. In the z-direction above the underride guard 16 and the support structures 14, a further degassing channel wall 18 in the form of a cooling plate 20 is shown (see Figure 1). Fig. 3 and Fig. 4), as well as a battery 22 arranged above this cooling plate 20 with one or more battery modules 24 (see Fig. 3) arranged as part of the degassing channel arrangement 10.
[0043] For example, in Fig. As can be seen in Figure 3, such a battery module 24 comprises several battery cells 26, which in this example are designed as prismatic battery cells 26. As can also be seen in particular in Fig. As can be seen in Figure 4, each of these cells 26 comprises a first cell side 26a, which faces the cooling plate 20, which can also be referred to as the cooling module 20. This respective first cell side 26a is equipped with a releasable cell degassing opening 28, for example a rupture membrane, which is also shown in Fig. 4 can be seen.
[0044] If a thermal runaway occurs in such a battery cell 26, gas escapes from the battery cell 26 through the accessible cell degassing opening 28. With the described positioning of the cells 26, the degassing path of the cells 26 therefore leads downwards, i.e., contrary to the depicted z-direction, through the cooling module, namely through a specific passage area 20a of the cooling module, as shown in Fig. 4 illustrates the space of the underride guard 16, more precisely the space 30 between the two degassing channel walls 12, 18, as is also shown in Fig. 3 and Fig. 4 can be seen.
[0045] In conventional arrangements, the escaping cell gas during thermal cell propagation can plastically deform the cooling module towards the underride guard, which can lead to a blockage of the degassing path into the underride guard and can prevent or hinder a desired burning through of the cooling module in the penetration area in the event of such a thermal event.
[0046] The aforementioned support structures 14 advantageously prevent such deformation of the cooling module 20 in the direction of the underride guard 16. For this purpose, an additional component, namely at least one support structure 14, which can also be referred to as a "spacer" 14 or standoff 14, is installed in the installation space 30 between the cooling module 20 and the underride guard 16 as a support function for the cooling module 20 and as a spacer between the cooling module 20 and the underride guard 16.
[0047] The cooling module spacer 14, with its support function, limits the deformation of the cooling module 20 in the event of thermal propagation or thermal runaway of a cell 26. If the inherent stiffness of the cooling module 20 is insufficient in the event of a thermal event, this spacer 14, acting as a so-called limiting block, prevents further deformation of the cooling module 20. Thus, an additional component, namely at least one support structure 14, can be optionally mounted on the underride guard 16, in particular on its upper surface 16a facing the cooling module 20 (see figure). Fig. 1) or alternatively on the underside 21 of the cooling module 20 (see Fig. 3) be attached.
[0048] In the Fig. In the example shown, the respective support structures 14 are arranged on the underride guard 16 and its upper surface 16a, respectively. Each of these two support structures 14 corresponds in position to a battery module 24, which is located above the associated support structure 14 in the z-direction. In this example, the area of the underride guard 16 shown, with the support structures 14 arranged on it, can be divided, for example, into a first area B1 and a second area B2, the boundary of which is located at the dashed line shown in the example. The first area B1 can be located directly below a first module 24 in the z-direction, and the second area B2 directly below a second module 24.The respective battery modules 24 can extend in the x-direction essentially over a length that corresponds to the length of the depicted support structures 14 in the x-direction. In other words, support for the cooling plate 20 over the entire length of each battery module 24 should be provided by means of the support structures 14. The respective spacer 14 preferably extends over the entire x-direction of the battery housing in which the battery modules 24 are accommodated, in order to cover as many cells 26 as possible.
[0049] The underride guard 16 may have further structures, geometries, or components on its upper surface 14, which are not shown here. As a result, the two support structures 14 may differ in their geometry, as is the case here, for example. The in Fig. The two spacers 14 shown in Figure 1 therefore have different geometries on their respective undersides in the direction of the underride guard 16, since the underride guard 16 does not have the same geometry in the area where the structures 14 are arranged.
[0050] Such a support structure 14, as a part of one such structure is also shown enlarged in a perspective view in Fig. As illustrated in Figure 2, the support structure 14 has at least one longitudinal structural element 32a, 32b and, in the present example, two longitudinal structural elements 32a, 32b running parallel to each other in the x-direction. These extend in the longitudinal x-direction in a wave-like manner, more precisely in a trapezoidal wave-like manner. Furthermore, such a support structure 14 comprises one or more transverse structural elements 32c. The longitudinal structural elements 32a, 32b can be connected to each other via these transverse structural elements. In particular, such a transverse structural element 32c can also be formed integrally with the longitudinal structural elements 32a, 32b. The Fig. The two support structures 14 shown in Figure 1 can each be manufactured as a single, one-piece component, for example, as an injection-molded part. However, it is also possible for each of these support structures 14 to be composed of several individual components, for example, two, three, four, or more. It is preferred that such a support structure 14 is subdivided into several individual components only in the x-direction, for example. In other words, it is advantageous if two longitudinal structural elements 32a, 32b are manufactured in one piece with at least one transverse structural element 32c. This facilitates the handling and assembly of the support structure 14. Such a support structure 14 can be attached, for example, by means of an adhesive strip 34 (see Figure 1). Fig. 2) be glued to one of the two degassing channel walls 12, 18, in the present example to the underride guard 16. Other fastening options are also possible. For example, if both the underride guard 16 and such a support structure 14 are made of a plastic, it is also possible to manufacture the underride guard 16 and the support structures 14 as a single injection-molded component.
[0051] The spacer 14 is attached, for example, to the underride guard 16 by means of an adhesive bond 34, such as double-sided adhesive tape 34, or adhesive. The adhesive bond is also preferably characterized by high temperature resistance when used in applications with high operating temperatures. Furthermore, it is advantageous if the adhesive bond 34 is designed to meet requirements regarding water, dirt, and dust and maintains this for the lifetime of the vehicle, meaning it retains its adhesive function for the entire service life of the vehicle in which this degassing channel arrangement 10 is used. Loads from shock and vibration are also preferably taken into account.
[0052] In particular, the cross braces 32c are partially designed with different widths in the y-direction for the two support structures 14, as shown in Fig. 1 can be seen. Between each pair of longitudinal structures 32a, 32b of such a support structure 14 there is an area BZ which extends in the z-direction below a cell degassing area BZ' (cf. Fig. 4) is located in which the respective cell degassing openings 28 of the cells 26 of the module 24 are arranged. These lie on a straight line in the x-direction. The longitudinal structures 32a, 32b are therefore arranged on both sides of this area BZ, which corresponds to the degassing area BZ'. This allows for very advantageous and uniform support in the immediate vicinity of the degassing area BZ'. In the event of degassing, this provides maximum stability and support through the support structures 14.
[0053] The longitudinal structures 32a, 32b are designed with corresponding free areas or passage areas 36 due to their wave-like course, as shown in Fig. 2 can be seen. A transverse structure 32c can also be designed such that it includes, on the one hand, support ribs 38, and on the other hand, connecting ribs 40 that extend in the transverse y direction and connect the support ribs 38 and the longitudinal structures 32a, 32b. The connecting ribs 40 can be lower in the z direction, i.e., with a smaller height, than the support ribs 38. This also results in possible gas passage areas in the x direction. Thus, if gas escaping from a cell 26 enters the space 30, i.e., the degassing channel 31 (cf. Fig. 3) if the flow is not significantly hindered by the support structures 14, as these allow flow both in the transverse direction y and in the longitudinal direction x.
[0054] Fig. Figure 3 shows a schematic cross-sectional view of a portion of the degassing channel arrangement 10 perpendicular to the transverse direction, or a side view looking in the transverse direction. In particular, a portion of a battery module 24 is shown, comprising a cell stack 24a extending longitudinally. In other words, the cell stack 24a comprises several cells 26 arranged side by side longitudinally. The cell stack 24a is further subdivided into several cell groups 25, which are separated from one another longitudinally by a cell group gap 42. Components, such as parts of the battery housing, partition walls, support walls, or similar elements, may also be located in this gap 42. The support structure 14 is preferably positioned such that the transverse structural element 32c is located below this cell group gap 42, in particular in a recess 20a' on the underside 21 located there (see Figure 3). Fig. 4) the cooling plate 20. Here, significantly higher loads can be absorbed from below without having to fear intrusion into the cells 26, which allows the transverse structural elements 32c, for example, to be made more robust.
[0055] In the Fig. In the example shown in Figure 3, the support structure 14 is no longer located on the underride guard 16, but instead on the degassing channel wall 18 above it, namely the cooling plate 20. As can be seen, the support structure 14 is designed to match the height of the gap 30 in the z-direction such that it does not rest against or contact the opposite degassing channel wall, in this case the underride guard 16. Thus, there is a gap 44 between the support structure 14 and the opposite degassing channel wall, in this example the underride guard 16. This will be explained in more detail below. Fig. 4 describes the cooling plate as including cooling channels 24a (see below). Fig. 4), which, for example, run essentially straight in the longitudinal direction, as well as cooling channel-free areas 20c (see Fig. 4) If the support structure 14 is arranged on the cooling plate 20, as illustrated in this example, the support structure 14 does not contact the cooling plate 20 in the area of the cooling channels 20a, but only in the area of the cooling channel-free areas 20c. In the Fig. In the side view shown in Figure 3, the support structure is therefore not located directly below the cooling channels 20c, but rather behind them in a transverse direction.
[0056] Fig. Figure 4 shows a schematic cross-sectional view of a degassing channel arrangement 10 in a cross-section perpendicular to the longitudinal direction x and in a side view looking in the x-direction. This cross-section passes through the area of a cell degassing opening 28 of a cell 26 of the module 24. In this example, the support element 14 is again arranged on the underride guard 16. Here too, the support element 14 is designed so that it does not contact the degassing channel wall 18 above it. Accordingly, there is also a gap 44 between the support element 14 and the cooling plate 20.
[0057] As can also be seen here, the cooling plate 20 includes cooling channels 20a. These are located between two plate elements of the cooling plate 20, in particular between at least two sheets enclosed by the cooling plate 20. Furthermore, a recessed cooling plate area 20b is located below the cell degassing area BZ'. Between the cooling channels 20a are small areas of the plate 20 in which no cooling channels 20a are arranged, and which can accordingly also be referred to as channel-free areas 20c. A similar channel-free area 20c adjoins the recessed area 20b and is not located below the cell degassing area BZ'. The support structure 14 is designed such that its highest support elements with respect to the z-direction are located directly below these channel-free areas 20c.In the event of deformation of the cooling plate 20 in the direction of the underride guard 16, the cooling plate 20 is supported by the support structure in these channel-free areas 20c of the cooling plate 20. If, instead, the support structure is arranged in contact with the cooling plate itself, as in the figure shown in . Fig. In the example shown in Figure 3, the support structure 14 is preferably also in contact with these channel-free areas 20c and not in areas of the cooling plate 20 where the cooling channels 20a or the recessed area 20b are located. Here, too, it can be seen that the support structure 14 is attached to the underride guard 16 by means of an adhesive tape 34. A battery cover or module cover may be located above the module 24, but this is not shown here.
[0058] Also in Fig.Figure 4 shows that the spacer 14 is not in direct contact with the cooling module 20, but rather a gap 44 has been created. This gap 44 prevents an additional load path into the cell module 24, so that even slight deformation of the underride guard 16 towards the cooling module 20 does not directly lead to cell intrusion. Furthermore, without this gap 44, there would be a risk of acoustic disturbances caused by the spacer 14 striking the cooling module 20 during normal driving. In the event of a thermal event, the support of the spacer 14 is provided by the media-carrying channels 20a of the cooling module 20, for example in the area between such a cooling channel 20a and the gas inlet channel 20b of the cooling floor 20. Due to its position, the vent element 28, i.e., the releasable cell degassing opening 28, of the cell module 24 is also protected as well as possible from potential impacts caused by an underfloor load.The geometry of spacer 14 is also chosen, for example, such that in the event of an underbody load and thus the collapse of spacer 14, i.e., compression of the spacer with respect to the z-direction, the two cross-sectional areas, for example, the sections facing the underride guard 16 and the sections facing the cooling module 20 of the wave-shaped longitudinal structure element 32a, do not overlap, but lie next to each other and thus do not obstruct one another. This further minimizes the risk of intrusion. This can be achieved by the described wave structure. The geometry of spacer 14 can also be chosen such that flow in the longitudinal and transverse directions is possible in the event of a thermal event, and that the support function can be performed. When additional support geometries in the form of the support structure 14 are introduced, the gas flow should therefore be contained within the underride guard 16 or the cooling module 20.The space 30 is not obstructed. As already described, this can be achieved by transverse ribs or connecting ribs 40 with reduced height and / or corresponding through-openings 36 in the individual structural elements. In other words, this can be accomplished by a corresponding local reduction in the rib height. Along the length of component 14 in the y-direction, additional support geometries and / or ribs in the form of transverse structural elements 32c can be attached to or encompassed by the spacer 14 at the locations below the cell group inter-area or inter-space 42, where, for example, the end plates of the modules 24 may be located. The ribs 32c, more precisely the support ribs 38, can then bear on the end plates located in space 42 and prevent cell intrusion in the event of a subfloor load.
[0059] Overall, the examples show how the invention can implement a support function of the cooling module in the degassing concept within the battery. QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] EP 4 207 438 A1
[0003]
Claims
[1] Degassing channel arrangement (10) with - a battery module (24) with at least one battery cell (26) having a first cell side (26a) with a releasable cell degassing opening (28) arranged on the first cell side (26a), - a first degassing channel wall (18) opposite the first cell side (26a) and comprising a passage area (20b) opposite the releasable cell degassing opening (28), and - a second degassing channel wall (12) which is opposite the first degassing channel wall (18) on a side facing away from the battery module (24), - wherein there is a space (30) between the first degassing channel wall (18) and the second degassing channel wall (12), characterized by, that the degassing channel arrangement (10) comprises a support structure (14) arranged in the space (30) for supporting the first degassing channel wall (18) against the second degassing channel wall (12) in the event of gas escaping from the releasable cell degassing opening (28), wherein the support structure (14) is arranged in contact with one of the two degassing channel walls (18, 12) in an undeformed initial state of the first and second degassing channel walls (18, 12) and does not contact the other of the two degassing channel walls (18, 12). [2] Degassing channel arrangement (10) according to claim 1, characterized by , that battery module (24) comprises a cell stack (24a) with several battery cells (26) arranged side by side in a longitudinal direction, wherein the support structure (14), in one part or in multiple parts, extends in the space (30) in the longitudinal direction over several or all of the battery cells (26) of the cell stack (24a). [3] Degassing channel arrangement (10) according to one of the preceding claims, characterized by , that the support structure (14) comprises a first longitudinally extending longitudinal structure element (32a, 32b) which is wavy in the longitudinal direction, in particular trapezoidal in shape, so that the height of the longitudinal structure element (32a, 32b) relative to the degassing channel wall (18, 12) on which the support structure (14) is arranged in contact varies in the longitudinal direction. [4] Degassing channel arrangement (10) according to any one of the preceding claims, characterized by, that the support structure (14) comprises a second longitudinal structure element (32b, 32a) extending in the longitudinal direction parallel to the first longitudinal structure element (32a, 32b), wherein the two longitudinal structure elements (32a, 32b) are arranged next to each other in a transverse direction, wherein there is an intermediate area (BZ) between the two longitudinal structure elements (32a, 32b) which is opposite a cell degassing area (BZ') of the battery module (24) in which the releasable cell degassing openings (28) of the battery cells (26) encompassed by the battery module (24) are located. [5] Degassing channel arrangement (10) according to any one of the preceding claims, characterized by, that the support structure (14) comprises at least one transverse structure element (32c) extending in the transverse direction and connecting the two longitudinal structure elements (32a, 32b), in particular wherein the two longitudinal structure elements (32a, 32b) and the at least one transverse structure element (32c) are designed as a single component, in particular an injection-molded component. [6] Degassing channel arrangement (10) according to one of the preceding claims, characterized by , that the cell stack (24a) is subdivided longitudinally into several cell groups (25), wherein a cell group space (42) is located between two of the cell groups (25), and the transverse structure element (32c) is opposite the cell group space (42). [7] Degassing channel arrangement (10) according to one of the preceding claims, characterized by, that the first degassing channel wall (18) has a bottom surface (21) facing the second degassing channel wall (12), wherein the bottom surface (21) has a recess (20a') in a region opposite the cell group space (42) in the direction of the battery module (24), wherein the transverse structural element (32c) is arranged in the recess (20a'). [8] Degassing channel arrangement (10) according to any one of the preceding claims, characterized by , that the first degassing channel wall (18) is designed as a cooling plate (20) with an integrated cooling channel arrangement comprising cooling channel sections (20a), wherein the cooling plate (20) has a first plate area (20c) extending longitudinally, in particular parallel to one of the cooling channel sections (20a), without cooling channels, wherein the first longitudinal structural element (32a, 32b) is opposite or arranged on the first plate area (20c). [9] Degassing channel arrangement (10) according to any one of the preceding claims, characterized by , that the second degassing channel wall (12) is designed as an underride guard (16). [10] Motor vehicle with a degassing channel arrangement (10) according to one of the preceding claims.