GAS DUCT CHAMBER AND BATTERY ARRANGEMENT FOR DUCTING GASES FROM A MOTOR VEHICLE BATTERY

Description

[0001] The invention relates to a gas discharge chamber for discharging gases from a motor vehicle battery having at least one first battery cell, wherein the gas discharge chamber has at least one chamber wall that separates an interior of the gas discharge chamber from an environment of the gas discharge chamber, at least one at least releasable first inlet opening, and at least one at least releasable outlet opening. The gas discharge chamber is designed such that a gas escaping from the at least one first battery cell, which is introduced into the gas discharge chamber through the at least one inlet opening, can be conducted through the gas discharge chamber to the at least one outlet opening and can be discharged from the at least one outlet opening. Furthermore, the invention also relates to a battery arrangement having a gas discharge chamber.

[0002] If a battery cell malfunctions in a high-voltage battery, especially for a motor vehicle, harmful gases may escape from the battery cell. These harmful gases can ignite and cause a damage to the entire high-voltage battery. Therefore, it is advantageous to divert these harmful gases from the battery and the motor vehicle in a targeted and safe manner. Various options are currently known for this purpose.

[0003] For example, DE 10 2012 214 984 A1 describes an exhaust gas guiding device with a main guide piece, which is suitable for use in the exhaust system of a motor vehicle with an internal combustion engine and battery. The main guide piece comprises a casing, a casing-enclosed cavity, an inlet opening, and an outlet opening arranged from the inlet opening in a main flow direction. The exhaust gas guiding device also has a secondary piece, which comprises another casing, another casing-enclosed cavity, an inlet opening, and an outlet opening, wherein the outlet opening of the secondary guide piece is connected to another inlet opening of the main guide piece. This allows the venting opening of the battery pack to be connected to the vehicle's exhaust system, allowing battery emissions to enter the exhaust system and ultimately escape from the vehicle into the atmosphere.

[0004] Furthermore, DE 10 2018 220 992 A1 describes a safety device for an electrochemical energy storage device that has a burst valve and a cooling device. Hot gases escaping through the burst valve are intended to be able to be cooled quickly. For cooling, a cooling plate can be provided, which is also designed as the cooling plate of the battery pack, so that the escaping gas can be guided along the underbody of the vehicle or along the cooling plate of the battery pack. Further relevant prior art is disclosed in documents JP 2016 035817 A, WO 2020 / 153017 A1, and US 2017 / 237055 A1.

[0005] Harmful gases escaping from battery cells should therefore not only be able to be diverted from the battery and the vehicle, but they should also be defused as far as possible in terms of their hazard potential during the degassing process, which in the examples mentioned above should be achieved by providing cooling and by routing them through an exhaust system.

[0006] Nevertheless, the aim to further increase safety in connection with the discharge of gases from a battery remains.

[0007] The object of the present invention is therefore to provide a gas discharge chamber and a battery arrangement which enable gas escaping from a battery cell to be discharged in the safest and most efficient manner possible.

[0008] This object is achieved by a gas discharge chamber and a battery assembly having 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.

[0009] A gas discharge chamber according to the invention for discharging gas from a motor vehicle battery having at least one battery cell according to independent claim 1.

[0010] The invention is based on several findings: Firstly, it is very advantageous not to discharge a gas to be discharged via a narrow channel, or at least not exclusively via a narrow channel, but to use the largest possible volume for this purpose, as can be provided, for example, by the gas discharge chamber as a whole. If a gas is introduced into such a gas discharge chamber with a large volume, the gas can expand and thus cools down. This, in turn, is based on the finding that cooling the gas is very important in order to prevent spontaneous combustion of the gas when it exits the gas discharge system. However, in order to be able to use the total volume provided by the gas discharge chamber as efficiently as possible to cool the introduced gas, it is advantageous to distribute the gas as widely and evenly as possible within this discharge chamber.If such a chamber only had one inlet and one outlet, the gas would take a very short flow path from the inlet directly to the outlet, which would mean that, depending on the relative positioning of the inlet and outlet, the maximum volume provided by the chamber could not be utilized. This can advantageously be changed by providing the gas distribution structure. This gas distribution structure, which may also have several individual gas distribution devices and / or gas distribution structure elements, can ensure distribution of the gas introduced into the gas discharge chamber before it leaves the interior again via the at least one outlet. This allows the gas discharge path to be specifically fanned out through the interior and distributed widely and evenly, making the entire volume of the gas discharge chamber usable.Such a broad and even distribution can, in turn, reduce gas velocities and temperatures, effectively preventing ignition of the flammable hydrocarbon components and pure hydrogen at the system outlet point. Furthermore, the provision of the gas distribution structure also promotes the separation of particles entrained in the gas. These particles are precisely the ignition sources when the gas exits the final outlet opening. Because this can also ensure that glowing particles are deposited or that these hot particles are additionally cooled when they encounter the gas distribution structure, there are no longer any ignition sources at the outlet, and the gas temperature is so low that spontaneous combustion can be ruled out.A further advantage of the gas distribution structure is that, thanks to its gas-distributing effect, efficient gas cooling can be achieved as the gas passes through the gas discharge chamber to the outlet opening, regardless of the inlet position—i.e., the position of the inlet opening relative to the interior. This also allows, for example, the gas to be optionally introduced via multiple inlet openings, e.g., those assigned to different battery modules. Furthermore, the gas distribution structure allows for very homogeneous pressure conditions to be established within the interior, which makes the gas discharge chamber less pressure-resistant overall and thus simpler in design.

[0011] According to the invention, the gas distribution structure has at least one gas discharge channel arranged in a first region of the interior space, which has at least one partially gas-permeable channel wall that at least partially separates the first region from the second region of the interior space, wherein the at least one first inlet opening opens into the second region of the interior space and wherein the at least one outlet opening opens into an interior of the gas discharge chamber in the first region, in particular wherein the at least one channel wall is designed such that a gas permeability of the channel wall varies depending on a distance from the at least one outlet opening, for example, increases with increasing distance. By means of such a gas discharge channel, gas distribution within the interior space can be implemented in a particularly advantageous manner.This at least one gas discharge channel has at least one gas-permeable channel wall that separates a first region of the interior of the gas discharge chamber, in which the outlet opening is arranged, from a second region of the interior into which the inlet opening opens. In other words, a gas introduced into the gas discharge chamber through the inlet opening must first penetrate the gas-permeable channel wall in order to reach the outlet opening. By varying the gas permeability of the channel wall depending on the distance from the outlet opening, the path of the gas discharge path can advantageously be influenced. For example, this can prevent the gas from flowing directly from the inlet opening to the outlet opening if the inlet opening is arranged near the outlet opening.For example, such a short, direct path can be prevented by reducing the gas permeability of the duct wall in this area, or can be provided with a correspondingly greater flow resistance. This allows, for example, the flow path or the gas discharge path taken by the gas to be specifically designed and extended. In particular, the gas discharge path can be specifically fanned out and distributed widely and evenly, making the entire volume of the gas discharge chamber usable. Such a wide and even distribution can, in turn, reduce gas velocities and gas temperatures in order to effectively prevent ignition of the flammable hydrocarbon components and pure hydrogen at the system outlet point. Furthermore, such an additional, partially gas-permeable duct wall can be used to specifically separate particles entrained in the gas, as already described above.Because this also allows glowing particles to settle, or because these hot particles are additionally cooled when they hit the partially gas-permeable channel wall, there are no longer any ignition sources at the outlet, and the gas temperature is so low that spontaneous combustion can be ruled out. Another particularly great advantage of the invention is that by varying the gas permeability of the channel wall, the described function can be achieved regardless of the position of the at least one inlet opening. Regardless of whether the at least one inlet opening is located very close to the outlet opening or not, a suitable distribution of the gas in the gas discharge chamber can always be achieved.This also makes it possible, for example, to provide multiple inlet openings at different positions in the gas discharge chamber, whereby a similar cooling and dispersing effect can always be achieved for the gas, regardless of which of the inlet openings the gas enters the gas discharge chamber through. This in turn makes it possible to provide the gas discharge chamber, for example, directly below or above a high-voltage battery of a motor vehicle and to couple the individual battery modules or cells to the gas discharge chamber via a direct supply connection. This allows gases from a battery cell to be introduced into such a gas discharge chamber via the most direct and shortest route. Regardless of the introduction position, efficient gas cooling can then be provided as the gas passes through the gas discharge chamber to the outlet opening.

[0012] A chamber wall is preferably understood to be the spatial and structural limitation of the total volume of the gas discharge chamber. The chamber wall can therefore optionally also be divided into several individual chamber walls, as will be explained in more detail later. The at least releasable first inlet opening and also the outlet opening can be provided in the chamber wall. The gas discharge chamber can have not only a single inlet opening and a single outlet opening, but optionally also several inlet openings and optionally several outlet openings. The number of inlet and outlet openings can vary.An at least releasable inlet opening should generally be understood to mean an inlet opening that is either permanently open, for example a permanent hole in the chamber wall, or that is fundamentally closed and only opens under a specific condition, for example in the event of excess pressure, or depending on the temperature. The at least releasable inlet opening can therefore, for example, only be opened when the at least one first battery cell assigned to the at least one first inlet opening outgasses. The at least one at least releasable outlet opening can also be designed such that it is either permanently present or is only opened when the at least one first battery cell outgasses. The inlet or outlet opening can, for example, be designed as a pressure relief valve or bursting membrane or melting membrane.

[0013] Furthermore, the invention also includes a battery arrangement with a gas discharge chamber according to the invention or one of its embodiments. In addition to the gas discharge chamber, the battery arrangement can also have the motor vehicle battery with the at least one battery cell. The motor vehicle battery can be designed, for example, as a high-voltage battery. The at least one battery cell can be a lithium-ion cell, for example. The motor vehicle battery can also comprise numerous battery cells, in particular also several battery modules, each with several battery cells. Each of the battery cells, including the at least one first battery cell, can then have a corresponding releasable venting opening through which the gas from the respective battery cell can escape in the event of venting of the respective battery cell. This can also be designed, for example, as a bursting membrane, pressure relief valve, or the like.

[0014] The outlet opening of the gas discharge chamber can represent a final outlet opening, from which the gas is ultimately discharged from the motor vehicle in which the gas discharge chamber is used. Alternatively, another gas discharge channel can be connected to the outlet opening, which directs the escaping gas to a final outlet opening of the motor vehicle. This offers greater flexibility regarding the positioning of the at least one final outlet opening.

[0015] Furthermore, it is conceivable for the gas discharge channel to have only one gas-permeable channel wall. The gas discharge channel can, for example, be defined as the entire first region of the interior space, whereby the interior space can be divided into only the first and second regions. The two regions are then separated accordingly by the gas-permeable channel wall. However, the gas discharge channel can also have two channel walls, in particular two such gas-permeable channel walls, so that the interior space is divided by these gas-permeable channel walls, for example, into at least three sub-regions, one of which, namely the first region, represents the gas discharge channel itself. Multiple gas discharge channels can also be provided, as will be explained in more detail later.In an advantageous embodiment of the invention, the gas permeability of the channel wall varies depending on the distance from the at least one outlet opening such that the gas permeability increases with increasing distance from the outlet opening. This is particularly advantageous because, if, for example, the inlet opening is arranged near the outlet opening, separated from the gas-permeable channel wall, it is more difficult for the gas to take the direct route to the outlet opening because the gas permeability of the channel wall is lower near the outlet opening. Here, therefore, only a small amount of gas passes through the channel wall, which accordingly forces the gas to flow further along the channel wall and penetrate it at another point. This is easier for the gas with increasing distance from the outlet opening due to the increased gas permeability.

[0016] For example, it can be provided that the channel wall has a first wall region and a second wall region that is farther away from the outlet opening than the first wall region, wherein a first gas permeability associated with the first wall region is smaller than a second gas permeability associated with the second wall region. Additionally, it is also conceivable that the gas permeability within the respective wall regions also varies depending on the distance from the outlet opening. Alternatively, the channel wall can also be segmented into discrete wall regions, within which the gas permeability is the same.

[0017] In this way, the flow resistance in the transverse flow direction, i.e. transversely, in particular perpendicularly to a longitudinal extension direction of the gas discharge channel, can be specifically adjusted, and specifically differently depending on the distance to the at least one outlet opening. However, this can be achieved not only by a different or varying gas permeability of the at least one channel wall of the gas discharge channel, but additionally or alternatively also by gas deflection structures, as will be explained in more detail later. This means that the channel wall can also be designed with a constant, non-varying gas permeability, or with a gas permeability that can vary in certain regions, but does not necessarily have to vary depending on the distance to the at least one outlet opening, for example. Different transverse flow resistances of the flow path in the above-defined direction can be specifically provided by these gas deflection structures, which then, for example,such a gas cross flow offers more or less resistance in the second direction depending on the distance to the outlet opening.

[0018] In a further advantageous embodiment of the invention, the outlet opening is arranged at one end of the gas discharge channel with respect to a longitudinal extension of the gas discharge channel. This makes it possible to ensure that the path the gas must take to reach the outlet opening is as long as possible. This, in turn, allows the gas to be cooled with maximum efficiency within the gas discharge chamber. Nevertheless, it would also be conceivable for the outlet opening to be arranged at a different position in the gas discharge channel, for example, in the center. Furthermore, it is preferred that only a single outlet opening is provided per gas discharge channel. This ensures defined flow conditions within the gas discharge chamber.

[0019] According to the invention, it is provided that the chamber wall comprises a first and a second chamber wall, which are opposite one another with respect to a first direction and delimit the gas discharge chamber in the first direction and opposite to the first direction. These two first and second walls are preferably the walls of the gas discharge chamber in terms of area. With regard to the intended installation position of the gas discharge chamber in a motor vehicle, it is preferred that the first direction corresponds to a vertical direction of the vehicle. Furthermore, it is advantageous if the gas discharge channel extends in a longitudinal direction that is perpendicular to the first direction, and wherein the at least one channel wall is arranged between the first and second chamber walls and connects the first and second chamber walls to one another. The longitudinal extension direction or longitudinal direction of the gas discharge channel can, for example, run in a second direction that is perpendicular to the first direction.In particular, the gas discharge channel can, for example, run straight in this second direction. In principle, however, it is also conceivable for the gas discharge channel not to run straight, but rather, for example, in a serpentine manner or something similar. This is, however, less preferred. Furthermore, the chamber wall can also comprise a third and a fourth chamber wall which delimit the gas discharge chamber with respect to the said second direction, which is perpendicular to the first direction, wherein the gas discharge channel runs from the third chamber wall to the fourth chamber wall. In other words, the gas discharge channel can extend over the entire length of the gas discharge chamber in the second direction. By means of the at least one gas-permeable channel wall, the gas distribution within the gas discharge chamber can advantageously be controlled in a targeted manner over its entire length due to the varying gas permeability.The gas discharge chamber can generally be designed, for example, such that its interior is divided into several individual regions that are separated from one another by several channel walls running in the second direction and designed to be gas-permeable, in particular as described for the at least one gas-permeable channel wall of the gas discharge channel. The individual regions are in turn divided into regions that define a gas discharge channel, each of which has an outlet opening provided therein. The remaining regions located between these gas discharge channels are gas inlet regions, each of which has gas inlet openings provided therein. With respect to the first direction, a respective gas discharge channel is likewise delimited by the first chamber wall and the second chamber wall. Perpendicular to the first direction, the gas discharge channel is correspondingly delimited by its respective gas-permeable channel walls.However, it is also conceivable for a gas discharge channel to be located in an edge region of the gas discharge chamber, so that a chamber wall also simultaneously represents a channel wall. In this case, for example, this does not necessarily have to be gas-permeable, but can be completely gas-impermeable. Furthermore, it is preferred for the interior of the gas discharge chamber to have a height in the first direction that is significantly smaller than all other dimensions of the interior of the gas discharge chamber in the second direction and a third direction perpendicular to the first and second directions. For this purpose, the extent of the gas discharge chamber in these second and third directions can be very large and, for example, extend over almost the entire underbody area of ​​the motor vehicle.

[0020] Therefore, a further particularly advantageous embodiment of the invention provides for at least part of the chamber wall to be provided by an underrun protection device for a motor vehicle. Thus, the area between the motor vehicle battery, in particular its underside, and the underrun protection device of the motor vehicle can be used as such a gas discharge chamber in a particularly advantageous manner. This area represents a particularly large volume, which can thus be advantageously used to integrate the at least one gas discharge channel there and to enable a broad and even distribution of the gas over a very large overall volume. Furthermore, existing structures of the motor vehicle can be used to design such a gas discharge chamber. Furthermore, such a gas discharge chamber can then be integrated into a motor vehicle in a particularly space-efficient manner.The underrun protection can, for example, represent one of the first or second chamber walls described above. If the underrun protection provides at least part of the first chamber wall, the second, opposite chamber wall is preferably provided by a part of a battery housing of the motor vehicle battery, in particular a housing base. It is therefore preferred that the motor vehicle battery, in its intended installation position, be arranged above the gas discharge chamber with respect to the latter.

[0021] The different gas permeabilities of the at least one channel wall can now be provided in different ways. For example, it can be provided that the first wall region is designed to be gas-impermeable and is arranged at the end of the gas discharge channel comprising the outlet opening. In other words, the region of the channel wall directly adjacent to the outlet opening can be designed to be completely gas-impermeable. Alternatively, this wall region immediately adjacent to the outlet opening can also be designed with at least low gas permeability. The first wall region can, for example, extend over a length in the second direction that is at least a quarter of the total length of the interior of the gas discharge chamber in the second direction.

[0022] According to the invention, the second wall region has gas-permeable holes, wherein an average passage area provided by the holes, relative to a partial region of the second wall region, increases with increasing distance from the outlet opening. This can be achieved, for example, in the simplest way by the holes, which can be arranged next to one another in the channel wall in the second direction, having an increasingly larger hole diameter with increasing distance from the outlet opening. Such hole diameters can be in the single-digit or multi-digit millimeter range. However, the channel wall can also be provided with finer structures in order to provide varying gas permeability. For example, the channel wall, for example the second wall region, can be designed as a type of mesh or grid, in particular a metal grid, or as a porous metal foam or the like.By adjusting the size of the pores of such a foam or the interstices of such a mesh or grid, the gas permeability can also be easily controlled and adjusted. The holes mentioned above can, in principle, have any desired geometry, for example, round, square, oblong, or similar.

[0023] According to the invention, the gas distribution structure has a plurality of gas discharge channels comprising the at least one gas discharge channel, wherein the gas discharge channels are arranged at a distance from one another, for example in the third direction defined above, wherein an outlet opening from a plurality of outlet openings of the gas discharge chamber opens into each gas discharge channel, and wherein a respective gas discharge channel has two gas-permeable channel walls opposite one another in the third direction. The gas discharge channels can, for example, run parallel to one another in the second direction. The regions in which the gas discharge channels are arranged can, for example, be defined as respective first regions of the interior of the gas discharge chamber, while the remaining regions are defined as second regions of the interior.Each two second regions are thus separated by a first region with a gas discharge channel, and two first regions, in which two gas discharge channels are arranged, are also each separated by an intermediate first region of the interior of the gas discharge chamber. The outlet openings of the gas discharge chamber are arranged exclusively within the gas discharge channels, with preferably only one outlet opening being provided within each gas discharge channel. One or more inlet openings can each open into the intermediate second regions of the interior. This makes it possible to achieve a particularly homogeneous and uniform distribution of the gas introduced into the chamber. This leads to a particularly homogeneous pressure distribution within the gas discharge chamber, which allows it to be designed for lower pressures overall.

[0024] In a further very advantageous embodiment of the invention, the gas discharge chamber has at least one releasable second inlet opening at a position different from the first inlet opening, wherein the second inlet opening opens into the second region of the interior, in particular wherein the second inlet opening is assigned to at least one second battery cell different from the at least one first battery cell. The gas from the first battery cell can therefore, for example, be introduced into the gas discharge chamber via the first inlet opening, and the gas which escapes from a second battery cell different from the first battery cell, which second battery cell can, for example, be part of a different battery module of the battery, can be introduced into the gas discharge chamber via the second inlet opening, and thus at a different inlet position.The design of the gas discharge chamber allows for a particularly uniform distribution of the gas throughout the entire gas discharge chamber, regardless of the inlet position, thus ensuring particularly efficient gas cooling until the gas exits from the at least one outlet opening. The respective inlet openings are preferably arranged in the aforementioned second chamber wall, which can be provided, for example, by a housing base of a battery housing. The outlet openings are preferably arranged on a wall of the gas discharge chamber that is different from this second chamber wall.

[0025] By providing a separate inlet opening for each battery cell or battery module of the motor vehicle battery, for example, it is also possible to minimize the paths from a particular battery to the gas discharge chamber for each battery cell or battery module. This is particularly advantageous because it allows the gas to be defused particularly quickly in terms of its hazardous potential.

[0026] According to a further very advantageous embodiment of the invention, several gas deflection structures are arranged within the gas discharge channel as part of the gas distribution structure to influence a flow path of the gas flowing in the gas discharge chamber. This has the great advantage that the gas can be additionally directed, redirected, and distributed in a targeted manner by such structures. Such structures not only have a gas-directing effect but also a decelerating effect, since the gas inevitably collides with these structures. Thus, such a gas deflection structure can also achieve targeted, additional particle separation.

[0027] According to a further very advantageous embodiment of the invention, the gas deflection structures are designed such that they at least partially decelerate a gas flowing through the at least one channel wall, and / or that they at least partially deflect a gas flowing through the at least one channel wall into the longitudinal direction of the gas discharge channel, and / or that they repeatedly deflect a gas flowing in the longitudinal direction of the gas discharge channel within the gas discharge channel into and / or against at least one deflection direction that encloses an angle with the longitudinal direction. In order to at least partially decelerate a gas flowing through the at least one channel wall, a structure can be provided which, for example, is designed in the manner of a web that extends from the first to the second chamber wall or even extends only partially in this direction, and which also has an extension in the second direction.In other words, such a web can be designed in the form of a plate that is oriented perpendicular to the third direction. Gas flowing through the channel wall in the third direction thus impacts this plate or web and is thereby slowed down. However, such a plate can also enclose an angle with the third direction that is different from 90 degrees and different from 0 degrees. The closer this angle is to 0 degrees or 180 degrees, the smaller the braking effect. If this angle is 45 degrees, for example, not only a braking effect but also, for example, a deflecting effect in the second direction can be achieved.Such inclined plate sections, which have a certain inclination to the longitudinal direction of the gas discharge channel, not only provide a decelerating effect on the gas currently flowing through the channel wall, but also a deflecting effect on the gas currently flowing along the gas discharge channel. For example, such webs or plates, which are alternately aligned along the gas discharge channel with respect to the angle of inclination, can achieve a deflecting effect on the gas flowing along this channel, which leads, for example, to a wave-shaped gas discharge path within the gas discharge channel. A respective plate can also have a curved cross-section perpendicular to the first direction, for example in the shape of a circular arc, and have a step parallel to the third direction, which transitions into a section parallel to the second direction via a curvature.In this case, numerous such plates or gas deflection structures can be arranged in the gas discharge channel, in particular in several rows spaced apart from one another in the third direction, e.g. in two or three rows per gas discharge channel. The arrangement of the plates within a row can be offset from one another from row to row, so that the through openings formed in the longitudinal direction, i.e. in the second direction, of a row by the spacing between two gas deflection structures are offset from one another in the third direction. The spacing of these gas deflection elements in the second direction or also the size or length of these gas deflection elements can also vary in the second direction. The design and geometry of the gas deflection elements can also vary in the second direction. In this way, the cross-flow resistance can also be influenced and specifically adjusted by the gas deflection elements in the second direction.

[0028] Such a wave-shaped or zigzag-shaped deflection within the gas discharge channel as described above can also be achieved, for example, by arranging the gas deflection structures themselves in a zigzag or wave-shaped manner in the second direction and, for example, parallel to one another in the third direction. Thus, the gas or its flow can be channeled again within the gas discharge channel in order to deflect it multiple times. This efficiently lengthens the gas path, achieves increasing gas cooling, and in turn promotes particle separation. Because the gas increasingly impacts such gas deflection structures, which consequently heat up, thermal energy can be efficiently transferred to these structures. This, in turn, also leads to gas cooling.Furthermore, various such gas deflection structures can be provided within a gas discharge channel, in particular having different geometries and / or fulfilling different of the aforementioned functions. It is also possible for such gas deflection structures to be provided within the gas discharge channel along its entire length in the second direction or only along a portion of its length in the second direction. This provides numerous possibilities for specifically influencing the gas flow.

[0029] If the gas discharge chamber has not just one gas discharge channel, but multiple gas discharge channels, these additional gas discharge channels can be configured in the same way as described for the at least one gas discharge channel. If the gas discharge channel or the remaining gas discharge channels have not just one gas-permeable channel wall, but multiple, in particular two, gas-permeable channel walls, these can also be configured in the same way as described for the at least one gas-permeable channel wall of the at least one gas discharge channel.

[0030] As already mentioned, the invention also relates to a battery assembly for a motor vehicle having a gas discharge chamber according to the invention or one of its embodiments. The advantages mentioned for the gas discharge chamber according to the invention and its embodiments thus apply equally to the battery assembly according to the invention. The battery assembly according to the invention additionally comprises the motor vehicle battery, which can be configured as described above.

[0031] Furthermore, a motor vehicle with such a battery arrangement shall also be considered to be part of the invention.

[0032] 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.

[0033] The invention also encompasses combinations of the features of the described embodiments. The invention therefore also encompasses implementations that each comprise a combination of the features of several of the described embodiments, unless the embodiments are described as mutually exclusive.

[0034] Exemplary embodiments of the invention are described below. Shown are: Fig. 1 is a schematic cross-sectional view of a battery arrangement with a gas discharge chamber according to an embodiment of the invention; Fig. 2 is a schematic view of a gas discharge chamber in a plan view with gas entering through a first inlet opening according to an embodiment of the invention; Fig. 3 is a schematic view of a gas discharge chamber in a plan view with gas entering through a second gas inlet opening according to a further embodiment of the invention; Fig. 4 is a schematic view of part of a gas discharge chamber in a plan view of part of a gas discharge channel according to an embodiment of the invention; Fig. 5 is a schematic view of part of a gas discharge chamber in a plan view of a gas discharge channel according to a further embodiment of the invention;6 shows a schematic representation of a part of the gas discharge chamber in a plan view with gas deflection structures integrated into the gas discharge channel according to an exemplary embodiment of the invention; Fig. 7 shows a schematic representation of a part of a gas discharge chamber in a plan view with gas deflection structures integrated into the gas discharge channel according to a further exemplary embodiment of the invention; Fig. 8 shows a schematic representation of a part of a gas discharge chamber in a plan view of a gas discharge channel with wave-shaped gas deflection structures according to a further exemplary embodiment of the invention; Fig. 9 shows a schematic representation of a part of a gas discharge chamber in a plan view of a gas discharge channel with longitudinally directed gas deflection structures according to a further exemplary embodiment of the invention; and Fig.10 a schematic representation of a gas discharge chamber in a plan view with several gas discharge channels, in each of which different gas deflection structures are integrated, according to a further embodiment of the invention. .

[0035] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual, independently considered features of the invention, which also further develop the invention independently of one another, insofar as they are within the scope of protection according to the appended set of claims.

[0036] In the figures, the same reference symbols designate elements with the same function.

[0037] Fig. 1 shows a schematic representation of a battery arrangement 10 with a gas discharge chamber 12 according to an exemplary embodiment of the invention. The battery arrangement 10 has a battery 14, which is preferably designed as a high-voltage battery 14. This battery 14 in turn comprises a plurality of battery modules 16, each of which in turn can comprise a plurality of battery cells. Two of the battery modules 16 are shown here as an example. However, the battery 14 can also comprise many more than two battery modules 16. The battery 14 can also have only a single battery module 16. The battery modules 16 are further arranged in a battery housing 18 of the battery. The housing 18 has a housing base 20, which in this example is additionally designed as a cooling base and, for example, comprises cooling channels 22 through which a cooling medium can flow.In this example, a further cooling system 23 is also arranged above the battery modules 16, which cooling system can also be designed with cooling channels through which a cooling medium can flow. The battery housing 18 also comprises side walls 24, as well as partition walls 26 between respective receiving areas for receiving the battery modules 16. The z-direction shown preferably corresponds to a vertical direction of the vehicle when the battery arrangement 10 is installed in a vehicle as intended. In this example, the gas discharge chamber 12 is arranged below the battery 14 with respect to the z-direction. The underside wall 28, which delimits the gas discharge chamber 12 or its interior 32 at the bottom, simultaneously also represents an underrun protection 30 of the motor vehicle. Thus, the available installation space between the battery 14 and the underrun protection 30 can advantageously be used as such a gas discharge chamber.The gases escaping from the battery cells of the battery modules 16 can be introduced into the gas discharge chamber 12 via an extremely short path. To enable the gas to enter, the gas discharge chamber 12 has at least one inlet opening 34a, 34b. In the present example, each of the battery modules 16 is assigned a corresponding inlet opening 34a, 34b. If, for example, the right-hand battery module 16 shown here or a cell contained therein is outgassing, the gas 36 escaping from this cell, which is illustrated here by arrows, can be introduced into the gas discharge chamber 12 via the assigned first inlet opening 34a. The same applies if a cell of the other battery module 16, in this example the left one, is outgassing; its gas would then be introduced into the gas discharge chamber 12 via the second inlet opening 34b.These inlet openings 34a, 34b can be designed as releasable inlet openings, meaning they do not have to be provided by permanent openings, but can, for example, only be opened in the event of outgassing from an associated battery cell. Theoretically, it is also conceivable to provide more than one inlet opening 34a per battery module 16, for example, per battery cell of such a battery module 16. However, more than one inlet opening 34a, 34b per battery module 16 can also be provided, but fewer inlet openings 34a, 34b per battery module 16 than the number of battery cells comprised by this battery module 16.

[0038] The gas discharge chamber 12 is generally bounded at the top and bottom by two chamber walls, namely an already mentioned lower chamber wall 28, which is provided by the underrun protection 30, and another upper chamber wall 38, which simultaneously represents the housing bottom 20 of the battery housing 18. Further chamber walls can also be provided in and against the x-direction and in and against the y-direction, which bound the gas discharge chamber 12 in the corresponding directions.

[0039] The interior space 32 of the gas discharge chamber 12 is now divided into several regions 32a, 32b. The regions 32a are referred to as first regions 32a, and the other regions 32b as second regions 32b. First and second regions 32a, 32b alternate in the x-direction and extend in the y-direction, preferably over the entire length of the interior space 32. The first regions 32a simultaneously define gas discharge channels 40. A respective gas discharge channel 40, which is sometimes also referred to simply as channel 40 below, further has at least one, preferably two, gas-permeable channel walls 42. A respective channel wall 42 thus separates a first region 32a from the second region 32b adjacent in or opposite the x-direction. The gas permeability of the respective channel walls 42 can be provided in a variety of ways, for example by holes 44 in the channel wall 42. As shown in this cross-sectional view in Fig. 1 As can be seen, these channel walls 42 run from the lower chamber wall 28 to the upper chamber wall 38, preferably not parallel to the z-direction, but at an angle. As a result, these gas discharge channel walls 42 can advantageously assume a dual function in combination with the underrun protection 30. If a force is applied to the underrun protection 30 from below in the direction of the battery 14, a targeted force deflection and introduction into the separating webs 26 or into the sides 24 can be achieved by means of these inclined channel walls 42, so that overall the force applied to the battery modules 16 can be kept as low as possible. However, this function does not necessarily have to be realized by this inclined course of the channel walls 42, but can also be realized, for example, by a certain dense composition or material composition of the channel walls 42. The gas discharge channels 40 orThe first regions 32a are preferably arranged below the separating webs 26 and / or side walls 24 of the battery housing 18 with respect to the z-direction. This also provides optimal protection for the battery modules 16 in the event of any force being applied or intruded from below onto the underrun protection 30.

[0040] In addition, structures 46 that perform a dual function are also arranged in the second regions 32b of the interior 32 of the chamber 12. On the one hand, these structures 46, which can be designed in particular as arched webs, can again perform a certain support and force introduction function, particularly in the case of a force being applied to the underrun protection 30 from below, in order to distribute the acting forces as effectively as possible and to avoid a high local force being applied to a battery module 16. In addition, these structures 46 are designed such that a gas can flow over them in the x-direction and, at the same time, a gas flow is also possible in the y-direction. In addition, they can achieve a certain gas-braking effect, especially in the x-direction or counter to the x-direction, which in turn contributes to slowing the gas flow and thus to cooling the gases.The arrows 36 illustrating the gas 36 become increasingly smaller as they progress along a flow path, which is intended to illustrate that the gas flow 36 exiting the inlet opening 34a is increasingly distributed over the entire internal volume of the chamber 12. This becomes even clearer with reference to . Fig. 2 and Fig. 3 explained.

[0041] Fig. 2 shows a schematic representation of the gas discharge chamber 12 in a plan view. In particular, Fig. 2 a view into the interior 32 of the chamber 12, without the upper wall 38 of the chamber 12 being shown. In this example, the chamber 12 comprises, by way of example, three gas discharge channels 40 in respective first regions 32a of the interior 32 of the chamber 12. The interior of a respective channel 40 is designated by 40a. The interior regions 32b lying between the channels 40 thus represent the second regions 32b of the interior 32. The first inlet opening 34a is in Fig. 2 illustrated by a circle. In order to discharge the gas 36 introduced into the chamber 12 through the inlet opening 34a from the chamber 12 again, the chamber 12 has a corresponding outlet opening 48 for each gas discharge channel 40. A respective outlet opening 48 is arranged at one end of a respective channel 40 with respect to a second direction, which corresponds to the y-direction shown here. The outlet openings 48 are also preferably arranged at an end of the gas discharge chamber 12 pointing towards the rear of the vehicle with respect to the y-direction and with respect to the intended installation position of the gas discharge chamber 12 in a motor vehicle. This makes it particularly easy to guide the discharged gases 36a to a final outlet position in the rear area of ​​the vehicle. The channel walls 42 are, due to their oblique course in the z-direction, as in Fig. 1 shown in Fig. 2 shown accordingly wide in the top view.

[0042] Due to the gas permeability of the channel walls 42, the gas 36 flowing into the chamber 12 through the inlet opening 34a, in particular into a second region 32b, can penetrate into the respective gas discharge channels 40. The gas 36 can not only penetrate into these, but also flow through them perpendicular to their course in or against the y-direction, i.e. in or against the x-direction. This advantageously allows a distribution of the gas 36 over the entire volume of the chamber 12. This distribution should be as homogeneous as possible so that almost constant pressure conditions are established across the entire chamber 12. It should also be avoided that the gas 36, which in the present example enters the chamber 12 very close to an outlet opening 48, is discharged again directly via such an outlet opening 48.This can advantageously be achieved by not designing the channel walls 42 to be homogeneous or isotropically gas-permeable, but rather by varying the gas permeability of these channel walls 42 depending on the distance to the outlet openings 48 of a respective channel 40, in particular increasing with increasing distance. In the present example, a respective channel wall 42 has a first wall region 42a and a second wall region 42b. The first wall region 42a is closer to an outlet opening 48 of the same channel 40 to which the first wall region 42a is also assigned. Accordingly, the gas permeability in the first wall region 42a is lower than in the second wall region 42b. In particular, in this example, the first wall region 42a is completely gas-impermeable, for example, designed as a solid wall or sheet metal, while only the second wall region 42b is gas-permeable.This allows for a particularly uniform distribution of the gas across the entire interior space 32. The gas entering through the inlet opening 34a cannot flow directly to an outlet opening 48, but rather first flows along the y-direction and then passes through the respective channel walls 42, particularly in the respective second regions 42b, and is thus distributed among the multiple gas discharge channels 40, flows along these to the respective outlet opening 48, and then leaves the chamber 12. The escaping harmful gas, designated 36a here, is significantly cooled and contains fewer or no particles. Spontaneous ignition or the outbreak of fire from the battery system is thus ruled out or the risk of such ignition is significantly reduced.

[0043] Fig. 3 shows again a schematic representation of the gas discharge chamber 12 from Fig. 2 , which in particular as well as Fig. 2 and Fig. 1 described. In this example, however, the gas enters the chamber 12 in a different position, namely through a further inlet opening 34c. The gas flowing through the chamber 12 is again designated 36. For reasons of clarity, not all arrows illustrating the gas 36 are provided with a reference symbol. Although the gas 36 enters the chamber 12 at a different location or entry position, the structures described can also bring about a uniform distribution of the gas 36 over the entire chamber interior 32. It is therefore advantageously possible, regardless of the entry position, to bring about a particularly broad, extensive and homogeneous distribution of the gas 36 over the entire interior 32 before the gas 36 leaves the chamber 12 again via the outlet openings 48.This allows the gas to be cooled to a maximum and numerous particles can be separated.

[0044] The different gas permeabilities of the walls 42 can be realized in different ways, as will now be shown by Fig. 4 und Fig. 5 described.

[0045] Fig. 4 und Fig. 5 each show a schematic representation of a part of the chamber 12 in a plan view of a part of a respective gas discharge channel 40. The channel walls 42 of the channel 40 are in Fig. 4 illustrated example, is formed with a type of mesh structure 50. This mesh structure 50 ensures a certain gas permeability, at least in the second wall region 42b. The channel walls 42 can, for example, be designed such that they are in the first wall region 42a (compare Fig. 2 ) are completely gas-impermeable, and in the second wall region 42b, as for example in Fig. 4 shown, are designed to be gas-permeable, in particular with a constant gas permeability in the y-direction. Alternatively, the gas permeability in the second wall region 42b can also be dependent on the distance to the outlet opening 48 (see Fig. 2 ) vary.

[0046] This can be achieved, for example, by an inhomogeneous formation of this network structure 50, or by holes 52 of different sizes, as in Fig. 5 shown. Fig. 5 shows another example of the design of the channel walls 42. As can be seen, the channel walls 42 in this example have holes 52 whose diameter increases in the y-direction and thus with increasing distance from the outlet opening 48. This makes it possible to achieve an increasing average gas passage area with increasing distance from the outlet opening 48 of the respective channel 40. Furthermore, numerous other configurations of these channel walls 42 are also conceivable in order to realize different gas permeabilities in different wall regions 42a, 42b or within such a wall region 42b.

[0047] Furthermore, it is particularly advantageous if gas deflection structures are arranged within the gas discharge channels 40, as will now be explained in more detail below.

[0048] This shows Fig. 6 a first example of such gas deflection structures 54 in a gas discharge channel 40 according to an embodiment of the invention. Here, again, a part of such a channel 40 is shown in a plan view. In this example, these gas deflection structures 54 are designed as inclined webs 54a. These webs 54a accordingly have an angle with the longitudinal direction of the channel 40, which extends in or against the y-direction, as well as an angle with the x-direction. This allows several functions and modes of operation to be implemented simultaneously. A gas flowing along the channel 40 is deflected several times by these structures 54, in particular in a wave-like or zigzag shape, in order to reach the outlet opening 48. This is illustrated by way of example by the gas discharge path P shown.In addition, the gas passing through the channel walls 42 in or against the x-direction is decelerated when it impacts these structures 54. This causes additional particles to be separated and the gas to be decelerated, resulting in cooling of the gas.

[0049] Fig. 7 illustrates another example of such gas steering structures 54, which, as shown in Fig. 7 shown, are designed as curved webs 54b. Gas flowing, for example, along the gas discharge channel 40 can thus be effectively prevented from escaping from this gas discharge channel 40. Conversely, gas penetrating the walls 42 is directed toward the channel 40, toward the outlet opening 48. A straight line flow through both channel walls 42 of the channel 40 can thereby be prevented or reduced.

[0050] Fig. 8 shows another example of such gas deflection structures 54, which extend in the channel direction as zigzag-shaped or wave-shaped structures. This also makes it possible to direct the gas 36 flowing in the channel 40 along a wave-shaped path P. This also deflects the gas 36 several times, thereby achieving increasing cooling and particle separation.

[0051] Fig. 9 shows another example of such gas deflection structures 54 in the form of webs 54d extending in the channel direction. The gas flowing through the channel walls 42, i.e., in the opposite x-direction or in the x-direction, can be efficiently decelerated. This, in turn, increases particle separation, slows down the gas, and, moreover, such structures 54d can also be used to control the proportion of gas to be introduced into the corresponding channels 40. Thus, it can be achieved that the gas 36 is distributed as evenly as possible among the multiple channels 40 as it flows in or against the x-direction.

[0052] The structures can generally be arranged both in a channel region which corresponds to the first wall region 42a with respect to the y-direction, and in a channel region which corresponds to the second wall region 42b with respect to the y-direction, or only in one of the two channel regions of the channel 40

[0053] In addition, the described structures 54 can be combined in any way within a single channel 40, or different structures 54 can be provided for different channels 40. The structures can extend over the entire length of the channel 40 in the y-direction or only a part of it. The combinability of these structures is described again in Fig. 10 explicitly illustrated.

[0054] Fig. 10shows a schematic representation of a gas discharge chamber 12 in a top view. Here, different structures 54 are shown for the respective channels 40, in particular again wave-shaped structures 54c, inclined webs 54a, and also vertical webs 54e not previously explained, through which, for example, targeted gas deflection through the channels 40 can be achieved. Many other structures 54 are also conceivable. Another major advantage of such structures is that the stability with regard to the underrun protection 30 can be further increased. This applies not only to these gas deflection structures 54, but also, for example, to the channel walls 42. Overall, the guide plates can be used to improve the structural connection of the underrun protection 30 to the battery system 14, for example the frame 24.This is particularly helpful in the event of damage to the subfloor, for example bollards falling.

[0055] Overall, the examples demonstrate how the invention provides harmful gas management in the event of a thermal runaway. This allows hot gas to be diverted via baffles and perforated plates in the area of ​​the underrun protection. This causes glowing particles to settle or cool down when they hit the baffles and perforated plates. At the outlet from the underrun protection, there are no longer any ignition sources, and the gas temperature is so low that spontaneous combustion can be largely ruled out. The design can be configured such that the function is independent of the position of the thermally continuous cell in the battery system or the inlet opening.

Claims

1. Gas discharge chamber (12) for discharging gases (36) from a motor vehicle battery (14) with at least one first battery cell, wherein the gas discharge chamber (12) - has at least one chamber wall (28, 30, 20, 38), which separates an interior (32) of the gas discharge chamber (12) from an environment of the gas discharge chamber (12), and comprises the one first and one second chamber wall (28, 30, 38, 20), which are opposite each other in relation to a first direction (z) and which delimit the gas discharge chamber (12) in the first direction (z) and counter to the first direction (z), - has at least one at least releasable first inlet opening (34a, 34b, 34c), - has at least one at least releasable outlet opening (48), - is configured such that a gas (36) leaving the at least one first battery cell, which is introduced through the at least one inlet opening (34a, 34b, 34c) into the gas discharge chamber (12), can be passed through the gas discharge chamber (12) to at least one outlet opening (48) and taken out from the least one outlet opening (48), and - has a gas distribution structure (40, 54, 46) arranged in the interior (32) of the gas discharge chamber (12), which is designed to distribute a gas (36) introduced into the gas discharge chamber (12) via the at least one first inlet opening (34a, 34b, 34c) before its discharge from the at least one outlet opening (48) in the interior (32) of the gas discharge chamber (12), - wherein the gas distribution structure (40, 54, 46) has at least one gas discharge channel (40) arranged in a first region (32a) of the interior (32), which has at least one partially gas permeable channel wall (42), which at least partially separates the first region (32a) from a second region (32b) of the interior (32), - wherein the gas discharge channel (40) extends in a longitudinal direction (-y), which runs in a second direction, and which is perpendicular to the first direction (z), - wherein the gas discharge channel (40) has two gas permeable channel walls (42) such that the interior (32) is divided into at least three sub-regions by these gas permeable channel walls (42), of which one, which constitutes the first region (32a), constitutes the gas discharge channel (40), - wherein one of the two gas permeable channel walls (42) is the at least one partially gas permeable channel wall (42), - wherein the two gas permeable channel walls (42) delimit the gas discharge channel (40) perpendicular to the first direction (z), - wherein the two channel walls (42) are each arranged between the first and second chamber wall (28, 30; 38, 20) and connect the first and second chamber wall (28, 30; 38, 20) to one another, and - wherein the at least one first inlet opening (34a, 34b, 34c) leads into the second region (32b) of the interior (32), characterized in that - the at least one outlet opening (48) leads into an interior (40a) of the gas discharge channel (40) in the first region (32a), and - a corresponding channel wall (42) is constructed such that a gas permeability of the corresponding channel wall (42) varies as a function of the distance from the at least one outlet opening (48) such that the gas permeability rises as the distance from the outlet opening (48) increases.

2. Gas discharge chamber (12) according to claim 1, characterized in that the channel wall (42) has a first wall region (42a) and a second wall region (42b), which is further away from the outlet opening (48) than the first wall region (42a), wherein a first gas permeability assigned to the first wall region (42a) is lower than a second gas permeability assigned to the second wall region (42b).

3. Gas discharge chamber (12) according to any one of claims 1 or 2, characterized in that the chamber wall (28, 30, 20, 38) comprises a third and a fourth chamber wall, which delimit the gas discharge chamber (12) in relation to the second direction (y), which is perpendicular to the first direction (z), wherein the gas discharge channel (40) extends from the third chamber wall to the fourth chamber wall.

4. Gas discharge chamber (12) according to any one of the preceding claims, characterized in that at least a part of the chamber wall (28, 30, 20, 38) is provided by an underrun guard (30) for a motor vehicle.

5. Gas discharge chamber (12) according to any one of claims 2 to 4, characterized in that the second wall region (42b) has gas permeable holes (44, 52), wherein an average passage area in relation to a partial region of the second wall region (42b), which is provided by the holes (44, 52), enlarges as the distance from the outlet opening (48) increases.

6. Gas discharge chamber (12) according to any one of the preceding claims, characterized in that the gas distribution structure (40, 54, 46) has multiple gas discharge channels (40) comprising the at least one gas discharge channel (40), wherein the gas discharge channels (40) are arranged at a distance from one another, wherein an outlet opening (48) of multiple outlet openings (48) of the gas discharge chamber (12) leads into each gas discharge channel (40), wherein a corresponding gas discharge channel (40) has two opposing gas permeable channel walls (42) in the third direction (x).

7. Gas discharge chamber (12) according to any one of the preceding claims, characterized in that the gas discharge chamber (12) has at least one releasable second inlet opening (34a, 34b, 34c) at a different position from the first inlet opening (34a, 34b, 34c), wherein the second inlet opening (34a, 34b, 34c) leads into the second region (32b) of the interior (32), in particular wherein the second inlet opening (34a, 34b, 34c) is assigned to at least one second battery cell that differs from the at least one first battery cell.

8. Gas discharge chamber (12) according to any one of the preceding claims, characterized in that multiple gas control structures (54, 54a, 54b, 54c, 54d, 54e) for influencing a flow path of the gas (36) flowing in the gas discharge chamber (12) are arranged within the gas discharge channel (40), wherein the gas control structures (54, 54a, 54b, 54c, 54d, 54e) are constructed such that - they at least partially slow down a gas (36) flowing through the at least one channel wall (42), and / or - they at least partially divert a gas (36) flowing through the at least one channel wall (42) in the longitudinal direction (-y) of the gas discharge channel (40), and / or - they deflect a gas (36) flowing within the gas discharge channel (40) in the longitudinal direction (-y) of the gas discharge channel (40) repeatedly in and / or counter to at least one deflection direction (x), which encloses an angle with the longitudinal direction (-y), e.g. in a wave-like manner.

9. Battery arrangement (10) for a motor vehicle with a gas discharge chamber (12) according to any one of the preceding claims and with that of the motor vehicle battery (14).