Exhaust systems, batteries and motor vehicles

Abstract

The invention relates to an exhaust device (12) for exhausting gas (20) from a battery (10) for a motor vehicle, the battery comprising at least one first battery cell (16) having at least one openable first exhaust opening (18), the exhaust device (12) having at least one first gas chamber (22) fluidically coupled to the openable first exhaust opening (18) of the at least one first battery cell (16), so that gas (20) exhausted from the exhaust opening (18) can be introduced into the at least one first gas chamber (22), and a particle catcher (26) for separating particles (28) from gas (20) flowing through the particle catcher (26), the particle catcher (26) being fluidically connected to the at least one first gas chamber (22). A first flow path (30) is provided via the exhaust gas device (12) from the at least one first gas chamber (22) into the particle trap device (26), the cross section of the first flow path being larger in at least one region of the particle trap device (26) than in the at least one first gas chamber (22).

Description

Technical Field

[0001] The invention relates to an exhaust device for exhausting gas from a battery of a motor vehicle, the battery comprising at least one battery cell, the at least one battery cell having at least one first exhaust opening that can be opened. The exhaust device has at least one first gas chamber and a particle collector, the at least one first gas chamber being fluidically / flowably coupled to the first exhaust opening that can be opened of at least one first battery cell, so that gas exhausted from the exhaust opening can be introduced into the at least one first gas chamber, the particle collector being used to separate particles from gas flowing through the particle collector, wherein the particle collector is fluidically connected to the at least one first gas chamber. In addition, the invention also relates to a battery having such an exhaust device and a motor vehicle having such a battery. Background Art

[0002] Batteries for electric vehicles or hybrid vehicles, in particular high-voltage batteries, are known from the prior art. Such high-voltage batteries typically have a certain number of battery cells, which may also be combined into a single cell module as appropriate. In the event of a battery cell failure, for example in the event of a short circuit, there is a risk of thermal runaway / thermal breakdown of such a battery cell. In the event of such a thermal runaway, the battery cell is typically vented, wherein particles from the cell are also carried away by the air flow. In order to allow such venting, the battery cell typically has an openable vent opening, for example in the form of a rupture membrane. In order to prevent particles escaping from the cell during venting from being deposited in the battery system in an uncontrolled manner, resulting in a blockage of the flow cross section and a short circuit of other cells in the battery, the gas discharged from the cell should be discharged in a controlled manner.

[0003] To this end, document DE 10 2018 125 446 A1 describes a battery housing for accommodating one or more battery modules, the battery housing having a housing section for partially defining the interior space of the housing, wherein the housing section has an integrated exhaust channel for discharging the medium discharged from the exhaust channel when the battery module is damaged. Here, the exhaust channel has at least one deflection area, which is configured to change the conveying direction of the medium. The deflection slows down the particles that may be entrained. This, for example, can prevent sparks that can ignite the exhaust from leaving the battery housing. However, there is also the risk that the particles are deposited at narrow locations due to the deflection and thus reduce or even block the flow cross section.

[0004] Furthermore, document DE 10 2011 105 981 describes a system for preventing lithium-ion battery failures, according to which the battery cell gases are processed in the exhaust system of an internal combustion engine. In order to supply the battery exhaust gas to the exhaust system, a fan or an air pump is also required. The problem with such active components is that their functionality cannot be ensured in the event of an accident of the motor vehicle. If these active components fail or their functionality is impaired, the battery gases cannot be discharged normally, which can have serious consequences.

[0005] In addition, document DE 10 2013 204 585 A1 describes a battery pack with an overpressure release device and a particle separator. Here, a special free space is provided for the exhaust situation in the battery pack housing, into which the released gas can diffuse and in which its temperature and pressure can be reduced. Subsequently, the gas is released outwardly through the overpressure release device and flows through a particle separator, for example, a particle separator in the form of a cyclone separator or a surface filter, which has a fiber composite or an open-pored sponge-like structure. Here, particles contained in the gas, such as graphite dust, can be filtered out when flowing through the particle separator, in order to avoid, for example, concentrations that can cause explosions in the discharged gas. However, the problem here is that when the gas cools by diffusing into the free space, a large number of particles contained in the gas have also been deposited, and therefore cannot reach the particle separator at all. There is also the risk of blockage of the flow path here again. Summary of the invention

[0006] It is therefore an object of the present invention to provide a ventilation device, a battery and a motor vehicle which allow the ventilation of gases from the battery cells to be as simple and reliable as possible.

[0007] This object is achieved by an exhaust system, a battery and a motor vehicle having the features according to the respective independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims, the description and the drawings.

[0008] The exhaust device according to the invention is used to discharge gas from a motor vehicle battery, the battery comprising at least one first battery cell having at least one openable first exhaust opening, the exhaust device having a first gas chamber, which can be fluidically coupled to the openable first exhaust opening of the at least one first battery cell, so that the gas discharged from the exhaust opening can be introduced into the at least one first gas chamber. In addition, the exhaust device comprises a particle catch device for separating particles from the gas flowing through the particle catch device, wherein the particle catch device is fluidically connected to the at least one first gas chamber. In this case, a first flow path from the at least one first gas chamber to the particle catch device is provided by the exhaust device, the cross section of the first flow path in at least one region of the particle catch device being larger than the cross section in the at least one first gas chamber.

[0009] The invention is based on the knowledge that several hundred battery cells with a total cell mass of approximately 2 kg are typically arranged in a high-voltage battery. In the case of thermal dissipation, i.e. heat dissipation, of the cells of a high-voltage battery, typically 50% of the cell mass is transported away by the resulting gas flow. If all the battery cells of such a high-voltage battery experience thermal runaway, this results in particles with a total mass of 1 kg being transported away. Such a large mass of gas particles can quickly lead to a complete blockage of the flow path if they are deposited uncontrolled at the wrong location. According to the invention, by virtue of the cross section of the flow path being larger in the particle catch device than in the gas chamber, it is advantageously possible to achieve an increase in the flow cross section when the gas flows from the gas chamber into the particle catch device. As a result, the velocity of the gas particles is reduced, whereby on the one hand the gas is cooled, and on the other hand a portion of the particles are deposited due to their lower velocity due to gravity. The invention is based on the knowledge that, by virtue of the increase in the cross section when the gas flows into the particle catch device, the particles are deposited exactly where they are supposed to be deposited, i.e. in the particle catch device, and not before in the gas chamber. This can advantageously prevent the flow path from being partially or completely blocked by particles deposited at locations where deposition should not occur. In other words, this can advantageously prevent particles from being deposited uncontrollably at narrow locations or other areas that are not provided for this purpose. At the same time, particle separation can be forced at a location provided and designed for this purpose, that is, in the particle capture device. This can not only achieve a cooled air flow that is ultimately led out of the battery and has a lower risk of spontaneous combustion, but also avoid dangerous blockages of the flow path on the other hand. In addition, another major advantage of the above-mentioned increase in the flow cross section in the particle capture device is that this can simultaneously provide a sufficiently large deposition space in the particle capture device, in which space is mainly provided for particle deposition, without blocking the flow path. Therefore, the cross-sectional expansion of the flow path when entering the particle capture device can be said to have a dual function, because it provides sufficient space for the deposition of particles, and on the other hand, the particle deposition is additionally forced by the reduction of the flow velocity. As a result, it is generally possible to provide a reliable discharge of gas from the battery in a particularly simple and effective manner.

[0010] Here, the exhaust device is preferably used in a battery configured as a high-voltage battery of a motor vehicle. Such a high-voltage battery can include a plurality of battery modules each having a plurality of battery cells. These battery cells and in particular at least one battery cell can be configured as a lithium-ion cell, for example. In addition, at least the first openable exhaust opening of at least one battery cell should be understood as an exhaust opening that is either permanently open or closed in a normal state, that is, when the battery cell is not exhausted, and is only opened under certain conditions, for example, when a certain pressure is reached inside the first battery cell and / or a certain cell temperature is exceeded. For example, the exhaust opening can be designed as a rupture membrane. In order to couple the gas chamber with the first exhaust opening, it can be simply arranged on the corresponding side of the battery cell, for example, so that the corresponding inlet opening of the gas chamber is arranged overlapping with the openable exhaust opening of the first battery cell. In addition, multiple battery cells can also be coupled to the gas chamber at the same time, especially through the corresponding openable exhaust openings of the multiple battery cells, which will be explained in more detail below.

[0011] Furthermore, the flow path is to be understood as the path through which the gas exhausted from the at least one first battery cell flows through the first gas chamber into the particle catch device and in particular flows through the particle catch device. The cross section of the flow path is therefore defined by the cross-sectional geometry of the gas chamber and the particle catch device perpendicular to the gas flow direction.

[0012] It is also particularly advantageous if the first gas chamber is designed in such a way that the gas emerging from the battery cells and entering the first gas chamber diffuses as little or at least not as strongly as possible. Otherwise, the gas would be cooled very strongly before entering the particle trap, so that too many particles would be separated before entering the particle trap, which could impede the flow.

[0013] Accordingly, a particularly advantageous design of the present invention is that at least one first gas chamber is configured as a first exhaust channel, the length of which in the longitudinal extension direction of the first exhaust channel is greater than the width and height of the first exhaust channel, wherein the first flow path extends along the longitudinal extension direction of the first exhaust channel. In other words, the gas chamber is configured as an elongated shape and has a cross section that is smaller than the length, thereby achieving the content just described above, that is, the gas will not diffuse as strongly as in a gas chamber with a large spatial expansion when it is discharged from at least one first battery cell. By setting an exhaust channel instead of a gas chamber with a large spatial expansion, it is advantageously achieved that the particle separation is concentrated on the particle capture device and on the other hand, a targeted deflection of the air flow is also achieved. Because compared with a gas chamber that is expanded in space, a directional flow can be generated through the exhaust channel without an excessively strong vortex, which is also very beneficial for the removal of particles and avoids the deposition of particles in undesirable narrow positions. In addition, providing the gas chamber as an exhaust channel has other advantages. Preferably, the exhaust channel is made of a very high temperature resistant material, such as ceramic or steel. Since the exhaust duct does not expand greatly in a flat manner, such a temperature-stable exhaust duct can be provided in a particularly cost-effective and weight-saving manner. Therefore, other components of the battery, such as the housing, do not have to be designed to be particularly temperature-resistant, since they do not come into contact with the hot gases flowing out of the battery cells.

[0014] Another great advantage of implementing the gas chamber as an exhaust gas channel is that, due to the usually very small flow cross section of the exhaust gas channel, an overall particularly large cross-sectional expansion can be provided during the transition to the particle trap, in particular by a multiple, for example at least 5 times, preferably at least 10 times, particularly preferably at least 20 times. Due to this particularly large cross-sectional expansion of the flow cross section during the transition of the flow path from the exhaust gas channel to the particle trap, a particularly intensive cooling of the gas and thus also a particularly effective particle separation can be provided.

[0015] It is also preferred that, for particle separation, the particle catcher not only provides a larger flow cross section than the exhaust channel in terms of the flow path, but also the particle catcher also has a mechanism for particle separation. Here, according to another very advantageous design of the present invention, it is provided that the particle catcher has at least one inlet area and an outlet area, wherein the particle catcher is constructed so that the first flow path is diverted multiple times from the at least one inlet area to the outlet area. In other words, the particle catcher can be constructed with a mechanical labyrinth for particle separation. At the same time, the cooling of the airflow is also achieved by the multiple diversions of the airflow. The cooling of the airflow in turn leads to a deceleration of the particles contained in the airflow, which thereby settles downward more and more due to gravity and can therefore be deposited on the wall of the particle catcher or other surfaces provided by the mechanical labyrinth. Therefore, in addition to the particle deposition and airflow cooling caused by the increase in cross section, this also provides an additional deposition and cooling effect.

[0016] In the simplest case, such multiple deflections can be provided by the particle catcher according to the siphon principle. Such multiple deflections can be designed significantly more complexly, as with the labyrinth. However, the described cross-sectional enlargement and its additional cooling and deposition effect make it possible to design the particle catcher as a whole significantly simpler with regard to such multiple deflections in order to achieve the desired cooling and particle deposition. This in turn has a positive effect on weight and costs and, in particular, on the required installation space.

[0017] In another advantageous embodiment of the invention, the particle trap device has a particle filter arranged in the first flow path, which particle filter is made in particular of steel wool. Such a particle filter can be provided, for example, in the form of steel wool padding. Particles of the gas flowing through the particle filter are captured in such a steel wool filter, so that an effective particle separation can also be provided here. Such a particle filter can be provided in particular as a supplement to the above-mentioned multiple deflection, or can also be provided as an alternative.

[0018] Furthermore, all the particle separation and air flow cooling methods described here have the commonality and advantage that no active components, i.e. components that must be operated electrically, are required for this purpose, so that the functioning of the components is independent of the functioning of the power supply of such components. In other words, this increases the possibility of being able to discharge gas from the battery cells unaffected and in a normal manner, especially in the event of an accident. In particular, the gas discharge can be achieved completely without any pumps or fans, etc. The gas flows through the flow path solely by the geometrical construction of the exhaust device and the exhaust gas pressure. This allows the gas to be discharged successfully not only more reliably, but also at a lower cost.

[0019] In another very advantageous embodiment of the present invention, the exhaust device has at least one second exhaust channel spatially separated from the first exhaust channel, the at least one second exhaust channel being fluidically coupled to the particle catch device and to the second exhaust opening of at least one second battery cell of the battery that can be opened, so that the gas discharged from the second exhaust opening can be introduced into the at least one second exhaust channel and can be introduced into the particle catch device along the second flow path. The second exhaust channel can also be constructed as described for the first exhaust channel. In addition, the second battery cell and its second exhaust opening are also the same. This embodiment has the great advantage that corresponding, separate exhaust channels can be provided for different battery cells or battery cell groups, each of which provides a corresponding flow path to the common particle catch device. In this case, the corresponding exhaust channels, i.e. the first and second exhaust channels, do not have to be coupled only to a single battery cell, in this embodiment only to the first battery cell or the second battery cell, but for example, multiple first battery cells can also be coupled to the first exhaust channel, and multiple second battery cells can be coupled to the second exhaust channel. Providing multiple such exhaust channels has multiple advantages. On the one hand, it can be ensured that, in the case of a small flow cross section provided by the corresponding exhaust channel, the gas escaping from the single cell can still be reliably discharged without blocking or overloading the relevant exhaust channel. However, if one of the exhaust channels is blocked for some reason, it can still be ensured that the gas is discharged from at least the other exhaust channels. However, the particularly great advantage of providing multiple exhaust channels is that the thermal decoupling of the battery cells connected to different exhaust channels can be increased. The gas flowing along another exhaust channel, for example, does not flow through the second battery cell coupled to the second exhaust channel. If the at least second battery cell is, for example, a battery cell that is still intact, and at least one first battery cell is a battery cell that is controlled and exhausted, it can be achieved through this thermal decoupling that the hot gas flowing out of at least one first battery cell and flowing through the first exhaust channel will not immediately cause overheating of at least one second battery cell that is still intact. Through this increased thermal decoupling, the heat propagation in the entire high-voltage battery can be delayed for a longer time, which in turn greatly improves the safety of the entire system.

[0020] In addition, the present invention also relates to a battery for a motor vehicle, having an exhaust device according to the present invention or one of its configurations. Therefore, the advantages described for the exhaust device according to the present invention and its configuration also apply to the battery according to the present invention. Here, the battery is preferably configured as a high-voltage battery. In addition, the battery includes at least one battery cell, in particular at least one first battery cell with an openable first exhaust opening as described above. In addition, the battery may also include at least one second battery cell with an openable second exhaust opening as described above. Preferably, the battery includes a plurality of battery modules, each of which has at least one battery cell, preferably a plurality of battery cells.

[0021] Here, another particularly advantageous design scheme of the battery proposes that the battery has a first battery area and a second battery area, the first battery area having at least one first cell row, the first cell row having a plurality of first battery cells arranged side by side along a first direction, these first battery cells having respective first openable exhaust openings, the second battery area having at least one second cell row, the second cell row having a plurality of second battery cells arranged side by side along the first direction, these second battery cells having respective second openable exhaust openings, wherein the particle collection device is arranged between the first battery area and the second battery area with respect to the first direction, wherein the first exhaust channel is coupled to the openable first exhaust opening of the first battery cell and extends in the first direction toward the particle collection device, and the second exhaust channel is coupled to the openable second exhaust opening of the second battery cell and extends in the opposite direction to the first direction toward the particle collection device.

[0022] In other words, the particle trap device can extend centrally between the first battery area and the second battery area. The exhaust channels extend from both sides of the central particle trap device in opposite directions toward the particle trap device. The airflow finally leaves the battery cell or the motor vehicle from the discharge opening, which can be arranged outside the battery or in the edge area of ​​the battery. The particle trap device arranged relatively centrally advantageously achieves that, for example, the gas discharged from the battery cell, which is also arranged in the edge area of ​​the battery, is first guided to the middle of the battery through the corresponding exhaust channel toward the particle trap device, passes through the particle trap device and then leaves the spatial area guided to the battery from the particle trap device to reach the final discharge opening. As a result, the gas escaping from the battery cell passes a very long distance, which has a great advantage that the gas can be additionally cooled due to the long distance. Here, the particles can also be separated again along this path. Here, the separation is relatively uniform along this very long path, so that there will be no local strong narrowing of the channel cross section due to uncontrolled particle separation. By means of the described geometric arrangement of the particle trap between the two battery regions and the exhaust duct leading to the central particle trap, safety during exhaust of the battery can be further increased.

[0023] The first cell row with a plurality of first battery cells may also include a plurality of battery modules, which in turn have a plurality of first battery cells. The same applies to the second cell row. In addition, the first battery region may also include a plurality of such cell rows, which extend, for example, in parallel with each other in a first direction. The second battery region may also have a plurality of second cell rows, all of which extend in the opposite direction to the first direction and may also be arranged parallel to each other. The particle capture device extends in a second direction in the longitudinal extension direction, in which these plurality of first cell rows and second cell rows may be arranged, for example, side by side with each other. This advantageously provides an elongated particle capture device in an efficient manner in terms of structural space, by means of which a cross-sectional expansion can then be achieved in a particularly simple manner when the gas is transferred from the gas channel or the exhaust channel to the particle capture device.

[0024] In another advantageous development of the battery according to the invention, the battery has a cooling bottom, on which at least one first battery cell is arranged, and the exhaust device has an exhaust duct, which is coupled to the outlet of the particle trap, wherein the exhaust duct is arranged on the side of the cooling bottom facing away from the at least one battery cell, in particular wherein the exhaust duct is provided by the spatial region between the cooling bottom and the underbody protection device. In other words, the gas discharged from the battery cells is guided through the respective exhaust duct into the particle trap device and after it has passed through the particle trap device is introduced into the exhaust duct, through which the gas is discharged from the battery and in particular from the motor vehicle. It is particularly advantageous here that the exhaust duct is provided by the spatial region between the cooling bottom and the underbody protection device of the motor vehicle, because this allows the existing structures in the vehicle to be used, which is particularly efficient in implementation. In addition, by selecting an additional exhaust duct that is realized by the existing structure, it can be achieved that the gas ultimately has to travel another distance before being discharged from the battery or the vehicle, thereby enabling the gas to be cooled further. Alternatively or additionally, the gas can also be guided through a chamber of the extruded profile forming the battery housing, so that such a chamber assumes the function of the exhaust duct. In this case, particles can continue to be deposited without any potential hazards arising therefrom.

[0025] The invention furthermore relates to a motor vehicle having a battery according to the invention or one of its embodiments.

[0026] The motor vehicle according to the present invention is preferably configured as an electric vehicle or a hybrid vehicle. In addition, the motor vehicle according to the present invention is preferably designed as an automobile, in particular a passenger car or a truck, or is designed as a passenger bus or a motorcycle.

[0027] The present invention also includes combinations of features of the described embodiments. Therefore, the present invention also includes implementations having combinations of features of a plurality of the described embodiments as long as they are not described mutually exclusively. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments of the present invention are described below. To this end, it is shown that:

[0029] Figure 1 A schematic cross-sectional view of a battery having a venting device according to one embodiment of the present invention is shown;

[0030] Figure 2 A schematic top view of a battery having a gas venting device according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0031] The embodiments set forth below are preferred embodiments of the present invention. In the embodiments, the described parts of the embodiments are the features of the present invention that can be considered independently of each other, and these features also improve the present invention independently of each other. Therefore, the present disclosure is intended to include the combination of the features of the embodiments except for the combinations shown. In addition, the embodiments can also be supplemented by other features in the features already described of the present invention.

[0032] In the figures, the same reference numerals respectively denote elements with the same function.

[0033] Figure 1 A schematic cross-sectional view of a battery 10, in particular a high-voltage battery 10, for a motor vehicle is shown, which has a venting device 12 according to an exemplary embodiment of the invention. In this example, the battery 10 has a plurality of battery modules 14, each battery module 14 having a plurality of battery cells 16. For reasons of simplicity, only some of the battery cells 16 are provided with reference numerals here. Four battery modules 14 are shown here by way of example. The battery 10 can generally also include more or fewer battery modules and, in particular, more or fewer battery cells 16.

[0034] Figure 2 In particular, a corresponding plan view of the battery 10 is shown without a housing cover, wherein here too, for reasons of clarity, some of the battery modules 14 and their individual cells 16 are provided with reference numerals by way of example.

[0035] If a battery cell 16 experiences thermal runaway, gases are generated inside such a battery cell 16, which gases must be discharged in a controlled manner to prevent the battery cells 16 from exploding. For this purpose, each battery cell 16 has an openable vent opening 18, which can be designed as a rupture membrane, for example. These openable vent openings 18 are located in the Figure 11 and 10. The gas 20 escaping from the battery cell 16 is shown as a dashed line on the upper side of the corresponding battery cell 16, wherein here again for the sake of clarity only some of the exhaust openings 18 are provided with reference numerals. The gas 20 escaping from the battery cell 16 is further indicated by arrows. Such gas 20 escaping from the battery cell 16 is initially extremely hot and contains material particles, such as dust, which, if deposited uncontrolled on narrow places in the battery system or also deposited on the outside, can, for example, lead to a blockage of the flow cross section and / or to a short circuit of other cells 16 inside the battery 10. In order to prevent this, the battery 10 advantageously has an exhaust device 12. The exhaust device includes an exhaust channel 22 on the one hand. Usually, the exhaust device 12 has at least one such exhaust channel 22, which can be coupled to the exhaust opening 18 of the battery cell 16 in a fluidic manner, so that the air flow 20 discharged from the exhaust opening 18 can be introduced or introduced into such an exhaust channel 22. This can be achieved simply by arranging the exhaust duct 22 above the battery cell 16 with respect to the z-direction shown and having corresponding duct openings 24 which are arranged overlapping the corresponding exhaust duct openings 18 of the battery cell 16. Furthermore, the exhaust duct 22 is designed to be as narrow as possible, so that the exhaust duct width B (see Figure 2 ) is preferably smaller than the module width b and also smaller than the length L of such an exhaust channel 22. In particular, the length L of such an exhaust channel 22 should be the maximum dimension of such an exhaust channel. In addition, the exhaust device 12 includes a particle trap 26, which is configured to separate particles from the gas 20 flowing through the particle trap 26. Such separated particles 28 are exemplarily located at Figure 1 In addition, the particle trap 26 is fluidically connected to each exhaust channel 22. Thus, a flow path 30 is provided, which defines the path through which the gas 20 flowing out of the battery cell 16 passes, so that the flow path 30 can also be regarded as consisting of Figure 1 This is indicated by the arrows shown. The flow path 30 extends from the individual cells 16 through the gas duct 22 to the particle trap 26 , through the particle trap as far as a final outlet opening 32 .

[0036] The flow path 30 is advantageously designed in such a way that the flow cross section increases at the transition from the exhaust channel 22 to the particle trap 26, in particular by a multiple, for example 20 times. For example, the cross section of the exhaust channel, that is, the cross section parallel to the yz plane in this example, can be 4 cm 2 , and the cross section of the particle trap 26 in the same cross-sectional plane, ie, the cross section parallel to the yz plane, may be 80 cm 2 Due to the fact that the particle trap 26 extends elongated in the y direction, mainly in Figure 2 As shown in , such a large cross section of the particle catch device 26 can be provided in a particularly simple manner. The cross-sectional expansion from the exhaust channel 22 to the particle catch device 26 can be used in the same way by all exhaust channels 22. This cross-sectional expansion has a great advantage, namely that the gas 20 can be cooled thereby, thereby promoting particle separation. In addition, by configuring the exhaust channel 22 itself with a relatively small cross section in the flow direction 30, it is achieved that the gas 20 does not diffuse particularly strongly when discharged from the battery cell 16, so that it is not yet strongly cooled in the exhaust channel 22 itself, thereby avoiding or at least reducing the uncontrolled separation / deposition of particles 28 in the exhaust channel 22 before reaching the particle catch device 26. Therefore, the particles 28 are separated only at a position where there is enough space for separation, that is, in the particle catch device 26.

[0037] In addition, the particle trap 26 is configured with a labyrinth system 34 in this embodiment. This labyrinth system 34 causes the flow path 30 to be turned multiple times from an inlet opening 36, in particular a plurality of inlet openings 36 assigned to the corresponding exhaust duct 22, to an outlet 38 of the particle trap 26. The labyrinth structure or the labyrinth system 34 can also have dead ends 40, which can also be used to increase particle separation. In addition to the cross-sectional expansion, the particle separation is also additionally promoted by this mechanical turning and labyrinth structure. In addition, the particle trap 26 can also have other or additional devices for particle separation, such as filtering steel wool wadding. Sparks can thus be filtered out particularly effectively.

[0038] The gas finally discharged from the outlet 38 of the particle trap 26 is therefore greatly cooled and contains only a small number of particles, which, however, are largely harmless in terms of a possible ignition of the exhaust gas due to their low velocity and low temperature. In addition, an exhaust duct 42 is coupled to the outlet 38 of the particle trap 26, through which the exhaust gas 20 can be discharged from the battery 10 and from the motor vehicle as far as the final outlet opening 32. Therefore, the gas 20 must also pass through another path before it is discharged from the opening 32, which results in additional deceleration and cooling of the gas 20.

[0039] It is also particularly advantageous if the exhaust duct 42 is provided by the existing structure of the battery 10 and / or the motor vehicle. In this example, the exhaust duct 42 is provided by a gap between a cooling bottom 44 of the battery 10 for cooling the battery cells 16 and an underbody protection 46 of the motor vehicle. The cooling bottom 44 can also have cooling ducts 48 through which a coolant can flow. Furthermore, the gap providing the exhaust duct 42 can extend over the entire xy plane of the battery 10.

[0040] Overall, these examples show how the invention can provide a particle filter in a high-voltage battery which allows particularly simple and safe discharge of gases escaping from the battery cells in the event of heat propagation.

Claims

1. A venting device (12) for venting gases (20) from a battery (10) of a motor vehicle, the battery comprising at least one first battery cell (16), the at least one first battery cell having at least one first venting opening (18) which can be opened, wherein: The exhaust device (12) comprises: at least one first gas chamber (22) which can be fluidically coupled to an openable first exhaust opening (18) of the at least one first battery cell (16), so that gas (20) exhausted from the exhaust opening (18) can be introduced into the at least one first gas chamber (22), a particle catcher (26) for separating particles (28) from a gas (20) flowing through the particle catcher (26), wherein the particle catcher (26) is fluidically connected to the at least one first gas chamber (22), It is characterized in that A first flow path (30) is provided from the at least one first gas chamber (22) to the particle collection device (26) through an exhaust device (12), wherein a cross section of the first flow path in at least one area of ​​the particle collection device (26) is larger than a cross section in the at least one first gas chamber (22), wherein the battery has a first battery area and a second battery area, the first battery area has at least one first cell row, the first cell row has a plurality of first battery cells arranged side by side along a first direction, and the second battery area has at least one second cell row, the second cell row has a plurality of second battery cells arranged side by side along the first direction, wherein the particle collection device is arranged between the first battery area and the second battery area with respect to the first direction.

2. The exhaust device (12) according to claim 1, It is characterized in that The at least one first gas chamber (22) is configured as a first exhaust channel, the length (L) of the first exhaust channel in the longitudinal extension direction (x) of the first exhaust channel being greater than the width (B) and the height of the first exhaust channel, wherein the first flow path (30) extends along the longitudinal extension direction (x) of the first exhaust channel.

3. An exhaust device (12) according to any one of the preceding claims, It is characterized in that The particle catch device (26) is designed to cool an air flow (20) flowing through the particle catch device (26) as it passes through.

4. The exhaust device (12) according to claim 1 or 2, It is characterized in that The particle catch device (26) has at least one inlet region (36) and an outlet region (38), wherein the particle catch device (26) is designed such that a first flow path (30) is deflected multiple times from the at least one inlet region (36) to the outlet region (38).

5. The exhaust device (12) according to claim 1 or 2, It is characterized in that The particle trap device (26) has a particle filter arranged in a first flow path (30).

6. The exhaust device (12) according to claim 2, It is characterized in that The exhaust device (12) has at least one second exhaust channel spatially separated from the first exhaust channel, the at least one second exhaust channel being fluidically coupled to the particle trap device (26) and being fluidically coupled to an openable second exhaust opening (18) of at least one second battery cell (16) of the battery (10), so that gas (20) exhausted from the second exhaust opening (18) can be introduced into the at least one second exhaust channel and into the particle trap device (26) along a second flow path (30).

7. The exhaust device (12) according to claim 5, characterized in that The particle filter is made of steel wool.

8. A battery (10) for a motor vehicle having a venting device (12) according to any one of the preceding claims.

9. The battery (10) according to claim 8, It is characterized in that The battery (10) has a first battery area and a second battery area, the first battery area having at least one first cell row, the first cell row having a plurality of first battery cells (16) arranged side by side along a first direction (x), the first battery cells having respective first exhaust openings (18) that can be opened, the second battery area having at least one second cell row, the second cell row having a plurality of second battery cells (16) arranged side by side along the first direction, the second battery cells having respective second exhaust openings (18) that can be opened, wherein a particle collector (26) is arranged between the first battery area and the second battery area with respect to the first direction (x), wherein a first exhaust channel is coupled to the openable first exhaust opening (18) of the first battery cell (16) and extends along the first direction (x) toward the particle collector (26), and a second exhaust channel is coupled to the openable second exhaust opening (18) of the second battery cell (16) and extends in the opposite direction to the first direction (x) toward the particle collector (26).

10. The battery (10) according to claim 8 or 9, It is characterized in that The battery (10) has a cooling bottom (44) on which the at least one first battery cell (16) is arranged, and the exhaust device (12) has an exhaust duct (42) which is coupled to an outlet (38) of the particle collector device (26), wherein the exhaust duct (42) is arranged on a side of the cooling bottom (44) facing away from the at least one battery cell (16).

11. The battery (10) according to claim 10, characterized in that An exhaust passage (42) is provided through a spatial region between the cooling bottom (44) and the bottom protection device (46).

12. A motor vehicle comprising a battery (10) according to any one of claims 8 to 11.

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