Exhaust duct, battery device and motor vehicle

Abstract

The invention relates to a venting channel (28) for a battery of a motor vehicle, wherein the venting channel (28) is designed to be arranged on a cell pack of the battery, comprising at least one battery cell (10), the battery cell comprising an openable cell vent opening. The venting channel (28) comprises a first channel wall (30) having an openable wall opening (38) assigned only to the cell vent opening (26). When the venting channel (28) is arranged on the cell pack, the wall opening can be opened by the gas pressure of gas (52) escaping from the assigned cell vent opening (26), so that the escaping gas (52) can be introduced into the interior (40) of the venting channel (28) through the opened wall opening (38).

Description

Technical Field

[0001] The present invention relates to a venting channel for a battery of a motor vehicle, wherein the venting channel is designed to be arranged on a cell pack of the battery comprising at least one battery cell, the battery cell comprising an openable cell venting opening. The present invention also relates to a battery device and a motor vehicle. Background Art

[0002] Battery cells used in motor vehicle batteries, particularly high-voltage batteries, often have pre-set vent openings to allow for the escape of gas from the battery cell in the event of overpressure within the battery cell—for example, due to intense gas generation within the battery cell during a thermal event—without causing an uncontrolled explosion of the battery cell. For example, patent document DE 10 2016 212 450 A1 describes a battery cell having such an openable vent opening configured with a rupture element.

[0003] Patent document DE 10 2017 218 752 A1 also describes a power battery for a motor vehicle having a plurality of battery cells, which are accommodated in a battery housing. Furthermore, a cover plate is provided for covering the battery housing, which seals the receiving chamber of the battery housing from the surrounding area. The battery cells also have a cover side facing the cover device and having corresponding ventilation elements. Hot gases generated in the battery cells can be discharged from the ventilation elements from the relevant battery cells into the receiving chamber of the battery housing. The ventilation openings face a region of the cover device that has a higher heat resistance than other regions.

[0004] Therefore, the hot gases escaping from the battery cells are usually diverted into the receiving area of ​​the battery housing. In order to achieve the discharge from such a battery housing, the battery housing can have corresponding valves or other openable openings, as described in patent document EP 2 244 318 B1.

[0005] Accordingly, the free space inside the battery housing serves as an exhaust duct for conducting this hot gas from the battery. This can also disadvantageously overheat intact battery cells and subsequently also cause heat penetration, thereby also increasing the risk of battery fire. Summary of the Invention

[0006] The object of the present invention is to provide a ventilation duct, a battery arrangement and a motor vehicle which allow the most efficient and safe possible removal of hot gases escaping from the battery cells of a high-voltage battery, in particular in the event of heat penetration of the battery cells.

[0007] This object is achieved by an exhaust duct, a battery arrangement 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 duct according to the present invention for a battery cell of a motor vehicle is designed to be arranged on a cell pack of a battery, the cell pack including at least one battery cell, the battery cell including an openable cell exhaust opening. The exhaust duct includes a first channel wall having openable wall openings assigned only to the cell exhaust openings. When the exhaust duct is arranged on the cell pack, the wall openings can be opened by the gas pressure of gas escaping from the assigned exhaust openings, so that the escaping gas can be introduced into the interior of the exhaust duct through the openable wall openings.

[0009] Thus, gases escaping from the battery cells only pass through the openable wall openings of the exhaust duct to reach the interior of the exhaust duct. Accordingly, the interior of the exhaust duct can advantageously be separated from the remaining interior space of, for example, a battery housing of a battery, which houses at least one cell pack having at least one battery cell. This advantageously allows for significantly more effective separation of hot gases escaping from the battery cells from other battery cells, thereby providing significantly better thermal decoupling. However, thermal decoupling is also significantly facilitated by, in the normal, conventional operating state of at least one battery cell—that is, when the battery cell whose openable exhaust opening is associated with the openable wall opening—is not venting, the wall opening in the first duct wall associated with the associated cell exhaust opening is closed, and in particular, the wall opening is only opened when the battery cell is venting. Within the scope of the present invention, exhausting of a battery cell is understood to mean, in particular, the escape of hot gases from the battery cell in the event of a thermal event, that is, in the event of thermal penetration of such a battery cell. Here, exhausting can also be understood to mean only the escape of hot gases in the event of thermal penetration of a battery cell. In the event of a thermal event, this typically involves only a single battery cell in the high-voltage battery. Over time, without countermeasures, the thermal event begins to spread from this battery cell due to the heat generation that begins in that battery cell, gradually causing heat to penetrate adjacent battery cells as well. In conventional battery systems, this spread is primarily accelerated by the hot gases escaping from the relevant battery cell. The present invention advantageously makes it possible, for example, to not open an openable wall opening, for example, associated with an unvented and still intact battery cell, or more precisely, its cell vent opening, even when another battery cell in the battery is already vented. Gas flowing through the vent channel from other battery cells can be significantly more effectively diverted away from the still intact battery cell, as this gas cannot pass through the associated openable wall opening of the still intact battery cell because the wall opening is still closed. This significantly more effectively delays the spread of heat in the battery. Furthermore, the vent channel allows for significantly more effective and targeted gas diversion.

[0010] Therefore, an openable wall opening is understood in particular herein to mean a wall opening that is not continuously open but is normally closed. This wall opening can, for example, be designed to open starting from a predetermined minimum pressure. It is preferred that the openable wall opening be associated with the cell exhaust opening such that it can only be opened under the gas pressure of the gas escaping from the associated cell exhaust opening. Thus, such an openable wall opening, which will be described in detail later, can also be configured with a bursting disc, etc., like the cell exhaust opening.

[0011] In a particularly advantageous embodiment of the present invention, the first channel wall is a battery housing floor, preferably a cooling floor for cooling the cell packs. In other words, the first channel wall is part of the battery housing and specifically provides the housing floor, which preferably also enables a cooling connection to at least one cell pack of the battery. For example, the cooling floor may have one or more cooling channels through which a coolant, such as a water-glycol mixture, can flow. Accordingly, the openable wall openings may be arranged in a region of the cooling floor where, for example, no cooling channels are present. This allows hot gases escaping from the battery cells to be particularly efficiently discharged from the battery and directed directly through the cooling floor between the cooling channels. Furthermore, the cooling floor is preferably arranged below at least one cell pack of the battery relative to the exhaust duct and, in particular, the conventional installation position of the battery in a motor vehicle. This means that the cooling floor thus defines the underside of the battery housing for the battery. The downward discharge of hot gases from the battery has the significant advantage that it can be directed away from the vehicle's passenger compartment in a targeted manner. This is because high-voltage batteries are typically arranged in the lower floor region of motor vehicles, i.e., below the vehicle's passenger compartment. Furthermore, by directing the hot air downward, a particularly rapid and effective removal from the entire vehicle can be provided. Thus, heating of other vehicle components, such as the vehicle floor, can be avoided in a particularly effective manner, or at least delayed or significantly reduced in extent.

[0012] In another highly advantageous embodiment of the present invention, the exhaust duct has a second duct wall, located opposite the first duct wall, and provided by the underbody protection. Thus, for example, relative to a conventional installation position of the exhaust duct in a vehicle, the exhaust duct can be bounded upward by the battery's cooling floor and downward by the vehicle's underbody protection. This gap provides ample space for effectively channeling the hot gases outward, particularly out of the vehicle. The appropriate outlet location can be appropriately selected, for example, to the side, front, or rear of the vehicle. However, it is also possible to channel the hot gases into another exhaust duct after passing through at least a partial section of the gap between the underbody protection and the cooling floor, and then out of the vehicle via this exhaust duct at any desired location. By not channeling the hot gases directly out of the vehicle along the shortest possible path, but, for example, initially passing through a portion of the gap between the underbody protection and the cooling floor and an optional exhaust duct, the advantage is that this allows for further gas deceleration and particle separation, ultimately resulting in significantly cooler gases ultimately escaping the vehicle and reducing the likelihood of spontaneous combustion. This further improves safety.

[0013] Nevertheless, it is also conceivable that, instead of providing an exhaust duct via the cooling floor and the underbody protection, the exhaust duct is arranged, for example, above the cell stack and provided, for example, via a housing cover arranged on the upper side over the battery and a vehicle floor positioned above the battery. This also provides a suitable gap for discharging hot air from the vehicle. However, due to the greater distance from the passenger compartment, it is preferred to provide for a downward exhaust duct, that is, through the cooling floor and into the gap between the cooling floor and the underbody protection.

[0014] Furthermore, it is preferred that the first channel wall has a plurality of openable wall openings, wherein each openable wall opening is assigned to exactly one openable cell exhaust opening of a plurality of corresponding battery cells of the battery. Typically, a high-voltage battery has a large number of battery cells. The exhaust channel should preferably be designed such that it also has an associated openable wall opening for each cell exhaust opening of a corresponding battery cell. This assignment relationship is particularly such that hot gas escaping from the associated associated cell exhaust opening causes the associated wall opening to open and passes through the ultimately opened wall opening. Therefore, the openable wall opening can preferably be opened only by the gas pressure of the gas escaping from the associated cell exhaust opening, and not by the gas pressure of other gases that may escape from other battery cells and their cell exhaust openings. This allows for a particularly advantageous, step-by-step, deflected opening.

[0015] In another advantageous embodiment of the present invention, the first channel wall has a material weakening in the region of the openable wall opening for providing a desired breaking point for opening the wall opening. The material weakening is particularly designed as a notch on the side of the first channel wall facing or facing away from the second channel wall, and the material weakening is particularly provided along a completely closed or open curve that runs at least partially angularly and / or circularly and / or elliptically. For providing a desired breaking point that opens only starting from a specific minimum pressure, which is reached when cells of the associated cell venting opening are vented, the embodiment of the channel wall having a material weakening in the region of the openable wall opening, particularly in the form of a notch, is particularly simple and cost-effective. The notch can have any desired shape.

[0016] A material weakening in the form of a groove can be easily introduced, for example, using a laser. Furthermore, such a groove can be arranged not only on the side facing the cell pack but also on the side facing away from the cell pack, and accordingly on the side facing or facing away from the second channel wall, such as the underbody protection. Grooving on both sides is also conceivable. Typically, the plate providing the cooling base has a thickness of 0.8 to 1.6 mm. Here, a material weakening in the form of a groove with a depth of between 0.1 and 0.3 mm, i.e., a recess, has proven sufficient to ensure automatic opening of the associated wall opening in the event of thermal penetration of the battery cells and the resulting gas escape. In addition to introducing such a groove directly into the cooling base or the first channel wall, it is also possible to provide such an openable wall opening by first cutting a corresponding hole into the first channel wall and sealing it with a metal film, for example, by lamination. For example, the first channel wall can be provided by an aluminum sheet, with the metal film being formed as aluminum foil. However, the advantage of configuring the material weakening as a groove is that it also allows for opening or unclamping in a specific manner. For example, the notch can be provided along an open, for example, U-shaped curve. When the opening is open, the channel wall can accordingly be folded open in a U-shape along this curve. However, the folded-open portion of the channel wall is not completely separated from the remaining area of ​​the channel wall, but remains fixed there, because it is not folded along a closed curve. Accordingly, targeted gas deflection can be provided by this protruding wall portion, and a certain shielding can also be provided, for example, in a specific flow direction. When the openable wall opening is folded open, the protruding portion can also, for example, come into contact with the open, protruding end of the underbody protection device and, for example, bend or deform in a curved manner thereby, thereby achieving targeted deflection of the gas entering the gap. This provides a variety of other possibilities for gas deflection. In particular, it is also conceivable that, for example, targeted gas flow deflection can be provided based on the position of the cell in the battery housing or the position of the cell relative to the entire vehicle.

[0017] Therefore, another advantageous embodiment of the present invention is that the first channel wall has an openable first wall opening associated with a first cell vent opening of a first battery cell, and an openable second wall opening associated with a second cell vent opening of a second battery cell, wherein the material weakening in the region of the openable first wall opening is designed differently than the material weakening in the region of the openable second wall opening, so that when the first wall opening is open, the opened first wall opening provides a corresponding first gas deflection characteristic, which is different from the second gas deflection characteristic provided by the second wall opening when the second wall opening is open. As already described above, for example, the opening of the openable wall opening can be selectively achieved by the design of a notch, thereby also providing a specific gas deflection characteristic, particularly with respect to the direction of gas deflection. The notch is preferably located on the battery housing base and can be designed in any desired shape, for example, circular, angular, oval, or partial, to enable controlled opening and targeted deflection of the gas flow, for example, depending on the position of the cell in the battery housing. In other words, in the event of a rupture, the structure can be opened differently and the gas flow can be redirected independently, depending on the position of the cell in the vehicle. This allows for a specific gas redirection for each battery cell, depending on its position within the battery and / or within the vehicle. For example, gas escaping from the battery cells in the first half of the battery, for example the left half, can be redirected to a gas channel located on a first side, for example the left side, that passes through the gap between the cooling channel and the underbody protection. Meanwhile, gas escaping from the battery cells on the second side, for example the right side, can be specifically directed to a gas channel located on a second side, for example the right side. The terms left and right can be used, for example, relative to the longitudinal direction of the vehicle in which the exhaust duct and the battery arrangement described below are used.

[0018] The present invention also relates to a battery arrangement having a degassing channel according to the invention or one of its embodiments. Furthermore, the battery arrangement comprises a battery having at least one cell pack, the cell pack comprising at least one battery cell having an openable cell degassing opening, wherein the degassing channel is arranged on the cell pack such that the openable wall opening of the first channel wall is arranged opposite the associated cell degassing opening.

[0019] In this case, the battery can be configured, in particular, as a high-voltage battery for electric or hybrid vehicles. A cell pack can generally be defined as a cell group comprising at least one battery cell. However, such a cell group preferably comprises a plurality of battery cells. Such a cell pack can also be provided in the form of a cell module comprising a plurality of battery cells interconnected by a retaining structure. The battery cells of a battery module can also be arranged, for example, in a battery module housing. Preferably, the battery comprises a plurality of battery cells, in particular a large number of battery cells. The battery cells can be configured, for example, as prismatic battery cells, round battery cells, or pouch-shaped battery cells. However, within the scope of the present invention, the battery cells are preferably configured as prismatic battery cells. Furthermore, the battery cells can be configured, for example, as lithium-ion battery cells. The cell vent openings of such battery cells are sealed during normal operation of the battery cells. For example, the openable cell vent openings can also be configured with a bursting disk. This bursting disk can, for example, be provided as a thin metal film, such as aluminum foil, which seals the opening in the cell housing. Under appropriate pressure within the battery cell, the metal film is destroyed or torn, thereby opening the opening in the cell housing. Furthermore, it is advantageous if the openable wall openings assigned to the respective cell vent openings are coordinated in size with the cell vent openings and, for example, can be designed to be exactly the same size as the assigned cell vent openings or slightly larger. Preferably, the respective wall openings are at most as wide as the thickness of the corresponding battery cell. In other words, the respective edge openings should not directly adjoin one another but rather be spaced apart from one another. This is necessary for thermal decoupling.

[0020] In another advantageous embodiment of the present invention, the battery cell comprises a first side with two cell pole connections and a second side opposite the first side, on which the cell exhaust opening is arranged. In other words, the cell exhaust opening of the respective battery cell is preferably arranged on the bottom side of the relevant battery cell, while the cell pole connections are, conversely, arranged on the opposite top side of the battery cell. This also has several advantages. On the one hand, this allows the gases escaping from the battery cell to be diverted downward through the cooling bottom into the interior of the exhaust duct. The cooling bottom is particularly simple to arrange on the side of the battery cell where no cell poles are arranged. Typically, this is the bottom side of the battery cell. At the same time, this also advantageously allows the hot gas flow escaping from the battery cell to be kept as far away from the cell poles or cell pole contacts as possible and to be separated from them. Since the hot gas escaping directly from the battery cell contains electrically conductive particles, the risk of voltage breakdown or arc formation and thus ignition of the gas can be reduced. This also allows the gas to be discharged more safely.

[0021] In another highly advantageous embodiment of the present invention, the vent channel is arranged on the cell stack such that the openable wall opening of the first channel wall is at a predetermined distance from the associated cell vent opening to provide a free space between the openable cell vent opening and the openable wall opening. This is particularly advantageous when the openable cell vent opening is designed, for example, as a bursting disk that opens at a predetermined pressure. In this case, the opening occurs outward due to the action of force, that is, from the interior of the battery cell to the outside. This predetermined distance and the resulting free space between the openable cell vent opening and the openable wall opening prevent blockage. In other words, it is ensured that the first wall channel does not hinder the opening of the cell vent opening. In this case, a small distance, for example, between 1 mm and 5 mm, preferably between 1.5 mm and 2.5 mm, for example, 2 mm, is sufficient to prevent such blockage.

[0022] In another advantageous embodiment of the present invention, a partition wall, particularly an O-ring, surrounding the wall opening and the associated cell ventilation opening is arranged between the openable wall opening and the associated cell ventilation opening. The O-ring separates the free inner region between the cell ventilation opening and the wall opening from the outer region between the cell stack and the ventilation channel, which is at least partially filled with a heat-conducting material. This heat-conducting material is used to thermally connect the battery cells to the cooling base. During battery production, the heat-conducting material is introduced between the cooling base and the battery cells in a flowable state, for example, by spraying or injecting it into the relevant gap between the battery cells and the cooling base or applying it to the cooling base. The cells are then assembled onto the heat-conducting material and pressed against this surface. Regardless of the method of introduction, this partition wall, for example in the form of an O-ring, can advantageously ensure that the region between the cell ventilation opening and the associated openable wall opening is precisely defined, thereby preventing the heat-conducting material from penetrating this region. For example, such an O-ring can be provided in the form of a foam tape, a rubber ring or a similar element, which prevents the heat-conducting substance, also called gap filler, from penetrating into the free area to be retained. This advantageously ensures that the gap filler does not fill the cavity or the free space between the openable wall opening and the openable cell vent opening, thereby preventing blockage during the gradual opening of the openable opening.

[0023] If, for example, no heat-conducting material is used or introduced between the first channel wall and the cell group, such a partition wall can be omitted accordingly. This particularly applies when at least initially non-flowable heat-conducting materials, such as heat-conducting pads, are used for the thermal connection.

[0024] Furthermore, the present invention also relates to a motor vehicle having a battery arrangement according to the invention or one of its embodiments.

[0025] The motor vehicle according to the invention is preferably designed as an automobile, in particular a passenger car or truck, or as a bus or motorcycle.

[0026] The present invention also includes combinations of features from the described embodiments. Therefore, the present invention also includes implementations that each have a combination of features from a plurality of the described embodiments, as long as these embodiments are not described in a mutually exclusive manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The embodiment of the present invention is described below.

[0028] Figure 1 A schematic diagram showing a battery cell for a battery device according to one embodiment of the present invention;

[0029] Figure 2 A schematic diagram illustrating a battery device having a channel wall of an exhaust channel and a plurality of battery cells according to one embodiment of the present invention;

[0030] Figure 3 A schematic cross-sectional view shows a battery device having a battery cell arranged in a vent channel according to one embodiment of the present invention;

[0031] Figure 4 a schematic cross-sectional view showing a detailed view of a connection between a single-unit exhaust opening and an openable wall opening according to one embodiment of the present invention; and

[0032] Figure 5 A schematic diagram showing the time course of battery cell exhaust according to one embodiment of the present invention. DETAILED DESCRIPTION

[0033] The embodiments described below are preferred embodiments of the present invention. In these embodiments, the components of the described embodiments are each individual, independently considered features of the present invention, and these features also independently improve the present invention. Therefore, this disclosure also encompasses feature combinations that differ from the illustrated embodiment feature combinations. Furthermore, the described embodiments may also be supplemented by other features of the present invention.

[0034] In the figures, the same reference numerals respectively denote elements with the same function.

[0035] Figure 1 A schematic perspective view of a battery cell 10 for a battery device 12 according to one embodiment of the present invention is shown. Figure 2 Such an exemplary battery arrangement 12 is shown in FIG. Figure 1The battery cell 10 shown by way of example in the figure is designed as a prismatic battery cell and has a cell housing 14, which provides an upper side 14a and a lower side 14b of the battery cell 10. Two cell pole terminals 16, 18 of the battery cell 10 are arranged on the upper side. One of the two cell pole terminals 16, 18 is designed as a positive pole and the other as a negative pole. In addition, other components can be arranged on the upper side 14a of the battery cell 10, such as a filling opening 20 for filling the cell housing 14 with electrolyte when manufacturing the battery cell 10, a data matrix code 22, which can be provided as a QR code, for example, and a thermochromic label 24. In addition, such a battery cell 10 has an openable exhaust opening 26. As shown in Figure 1 As shown in FIG, this ventilation opening can also be arranged on the upper side 14a of the battery cell 10, but in the exemplary embodiment described below, it can be arranged on the lower side 14b of the cell housing 14. For example, such a ventilation opening 26 can be provided by a bursting disk that ruptures in the event of overpressure, for example, by a thin metal film that closes the opening in the cell housing 14.

[0036] In conventional batteries, especially high-voltage batteries, for electric or hybrid vehicles, direct hot gas deflection for each cell is not possible, especially not downward. Instead, additional fire protection plates are often used in the battery housing cover to prevent penetration of the cells into the vehicle interior. However, these fire protection plates are very expensive and heavy. However, the present invention and its design now offer significantly more effective gas deflection.

[0037] to this end, Figure 2 The schematic diagram of a battery arrangement 12 with a plurality of battery cells 10 is shown. The battery cells 10 can be Figure 1 The structure is as described, with the difference that the above-mentioned cell exhaust opening 26 is not arranged on the upper side 14a of the relevant cell housing 14, but on the contrary on the opposite lower side 14b. Figure 2. Furthermore, the battery device 12 comprises an exhaust duct 28, of which only a part, namely a first duct wall 30, is shown in this example, which faces a cell group 32 provided by a plurality of battery cells 10. The exhaust duct 28 can be delimited on the side opposite this first duct wall 30 by a second duct wall 34, which is shown here only as a dashed line. It is particularly advantageous here if the first duct wall 30 is provided, for example, by a cooling bottom 36 of a battery housing of a battery comprising the cell group 32 and the second duct wall 34 by an underbody protection device of a motor vehicle. Advantageously, the exhaust duct 28 can now have a plurality of openable wall openings 38 on the first duct wall 30. In this case, each wall opening 38 is assigned to exactly one cell exhaust opening 26. Thus, in Figure 2 In addition, there is also such an openable wall opening 38 in the first channel wall 30 below the corresponding battery cell 10. In addition, it is provided that the other battery cells 10 are arranged in the corresponding Figure 2 However, in order to better illustrate the openable wall opening 38, only Figure 2 These other battery cells are not shown in the figure. Under normal circumstances, the openable wall opening 38 is closed and is only opened when the relevant battery cell with the associated cell venting opening 26 is vented. The gas discharge is then achieved by gradually opening the gas deflection structure provided in the battery housing bottom 36 via the openable wall opening 38 in a deflected manner. The gas deflection structure is preferably designed so that no obstruction can occur in the overall combination of the cell 10 and the housing bottom 36 and the free space therebetween. The respective openable wall opening 38 can also be provided as a bursting opening, for example, as described for the battery cell 10 with its cell venting opening 26, or by a material weakening in another manner, for example in the form of a groove, in the first channel wall 30. Therefore, if an overpressure occurs in a specific cell 10, the cell exhaust opening 26 on the lower side of the cell is first opened, whereby the gas generated in the cell 10 can escape from the cell exhaust opening directly to the associated openable wall opening 38 of the first channel wall 30, whereupon the openable wall opening is also opened and thereby guides the escaping gas into the interior 40 of the exhaust channel 28.

[0038] To achieve better thermal decoupling, it is particularly advantageous to provide each cell 10 with its own associated, openable wall opening 38. Accordingly, the plurality of wall openings 38 are preferably spaced apart, particularly in the y-direction, and have a width in the y-direction that is at most equal to the thickness of the associated cell 10 in the y-direction, for example, a maximum of 30 mm. The thickness of the cell 10 in the y-direction is smaller than both the width of the cell 10 in the y-direction and the height of the cell 10 in the z-direction. The plurality of cells 10 of a cell group are arranged side by side in the y-direction.

[0039] Figure 3 A schematic cross-section through a battery arrangement 12 according to an exemplary embodiment of the present invention is shown. The battery arrangement 12 again comprises a battery cell 10 which can be constructed as described above and a venting channel 28 which can also be constructed as described above. Figure 4 The connection region for connecting the openable individual exhaust opening 26 to the openable wall opening 38 is shown again. Figure 3 A detailed view of the local area in the Figure 3 In the embodiment, the first channel wall 30 is preferably also designed as a cooling bottom 36. In other words, the first channel wall 30 preferably provides the bottom of the battery housing, on which the battery cells 10 are arranged, and the bottom simultaneously provides cooling channels 42 through which a cooling medium can flow. Furthermore, in the present case, the respective battery cells 10 are connected to the cooling bottom 36 via a heat-conducting substance 44, also called a gap filler. By means of this heat-conducting substance 44, heat dissipation from the battery cells 10 to the cooling bottom 36 can be achieved more effectively during normal operation. The openable wall opening 38 is arranged directly opposite the associated openable cell exhaust opening 26 of the battery cells 10, as can be seen in particular in the embodiment. Figure 4 As can be clearly seen in , it is also advantageous if the openable wall opening 38 has a predeterminable minimum distance d from the openable cell vent opening 26 , preferably between 1 mm and 3 mm, for example, 2 mm. This ensures that no blockage occurs when the cell vent opening 26 and subsequently the openable wall opening 38 are continuously opened. Furthermore, in this example, a partition wall, in the form of an O-ring 46 in this example, is arranged in the area between the cell vent opening 26 and the openable wall opening 38 . In this example, the O-ring 46 is circular, corresponding to the openable wall opening 38 , and surrounds the openable wall opening 38 and the associated cell vent opening 26 , thereby creating a free space 48 between the openable wall opening 38 and the associated openable cell vent opening 26 . During battery manufacturing, this free space 48 is maintained by the O-ring 46 during the application of the gap filler 44 . This ensures that the gap filler 44 cannot enter this free space area 48 during manufacturing.

[0040] For example, the cooling base 36 can be composed of a cooling plate 36a and a base plate 36b, between which cooling channels 42 are formed and which can each be designed, for example, in the form of a plate. The openable wall opening 38 can then be correspondingly formed in one of the plates 36a, 36b, for example, in this case, in the base plate 36b.

[0041] It is particularly advantageous here, for example, to provide the openable wall opening 38 by, for example, a notch in the bottom 36 for the corresponding associated cell exhaust opening 26. When the exhaust pressure of the cell 10 increases, the notch opens and directs the gas flow between the bottom plate 36 and the underbody protection device 34 in a targeted manner outward. This makes it possible to prevent or at least delay the contamination of other cells 10 due to better thermal decoupling. Now, in more detail, according to Figure 5 Describe this step-by-step opening in a deflection manner.

[0042] to this end, Figure 5 The chronological sequence of such an opening process is shown with the battery cell 10 venting. Figure 5 The battery device 12 is shown at four different times t1, t2, t3, t4, more precisely at Figure 4 Therefore, the battery device 12 can be constructed again as described above.

[0043] At the first moment t1, not only the cell exhaust opening 26 but also the openable wall opening 38 are still in an intact state. This means that not only the cell exhaust opening 26 but also the associated openable wall opening 38 are still closed in this case. Due to the thermal event of the cell 10, gas 52 is generated in the interior 50 of the battery cell 10, which leads to an increase in the gas pressure in the interior of the battery cell 10. As shown at the moment t1, this increased gas pressure acts on the openable cell exhaust opening 26 and causes the cell exhaust opening 26 to open when a certain threshold value is exceeded, as is the case at the moment t2. Subsequently, the gas flow 52 flowing out of the cell 10 is accordingly directed directly to the associated openable wall opening 38, whereby the wall opening is also opened, as shown at the moment t2. Figure 5 As shown in FIG at time t3. Due to the continuous gas flow 52, ​​not only the part of the cell housing 14 but also the channel wall 30 and the wall opening 38 in the area of ​​the corresponding cell exhaust opening 26 are deformed outwards, that is, in the direction of the interior 40 of the exhaust channel 28. Figure 5This final state is shown at time t4 in FIG. Thus, the gas flow 52 reaches the interior 40 of the exhaust duct, which is provided by the gap between the underbody protection 34 and the battery or vehicle's cooling floor 36. In this gap, the outflowing gas 52 can also be directed in a targeted manner to an exhaust pipe or directly out of the vehicle.

[0044] Overall, the example demonstrates how the present invention can provide an actively controllable exhaust system. Depending on the exhaust system, the gas opening system is preferably integrated directly into the floor. The floor can be partially equipped with grooves beneath the cells. When the exhaust pressure in the cells increases, the grooves open and specifically direct the gas flow between the floor and the underbody protection outward to prevent contamination of other cells. This allows for rapid removal of hot gases and prolonged protection of the vehicle occupants. Furthermore, by eliminating additional measures, cost and weight savings can be achieved.

Claims

1. A vent channel (28) for a battery of a motor vehicle, wherein: The vent channel (28) is designed to be arranged on a cell group of a battery comprising at least one battery cell (10), wherein the at least one battery cell comprises an openable cell vent opening. It is characterized by: The exhaust channel (28) comprises a first channel wall (30) having an openable wall opening (38) assigned only to the cell exhaust opening (26). When the exhaust channel (28) is arranged on the cell group, the wall opening can be opened by the gas pressure of the gas (52) escaping from the assigned cell exhaust opening (26), so that the escaping gas (52) can be introduced into the interior (40) of the exhaust channel (28) through the opened wall opening (38). The first channel wall (30) is a cooling bottom (36) for cooling the cell group, and the wall opening (38) is arranged in a region of the cooling bottom (36) which has no cooling channels through which a coolant can flow. The cooling bottom (36) is configured in the region of the wall opening (38) to be further away from the at least one battery cell than the rest of the cooling bottom (36), so that the wall opening (38) has a predetermined distance (d) from the associated cell exhaust opening (26) for providing a free area (48) between the cell exhaust opening and the wall opening.

2. The exhaust passage (28) according to claim 1, It is characterized by: The exhaust duct (28) has a second duct wall (34) lying opposite the first duct wall, the second duct wall being provided by the underbody protection device (34).

3. The exhaust channel (28) according to claim 1 or 2, It is characterized by: In the area of ​​the openable wall opening (38), the first channel wall (30) has a material weakening portion, which is used to provide a theoretical breaking point for opening the wall opening (38), and the material weakening portion is configured as a groove on the side of the first channel wall (30) facing and / or facing away from the second channel wall (34), and the material weakening portion is provided along a completely closed or non-closed curve, which extends at least partially angularly and / or circularly and / or elliptically.

4. The exhaust passage (28) according to claim 3, It is characterized by: The first channel wall (30) has an openable first wall opening (38) associated with a first cell exhaust opening (26) of a first battery cell (10), and an openable second wall opening (38) associated with a second cell exhaust opening (26) of a second battery cell (10), wherein the material weakening in the region of the openable first wall opening (38) is configured differently from the material weakening in the region of the openable second wall opening (38), so that when the first wall opening (38) is opened, a corresponding first gas deflection characteristic is provided by the opened first wall opening (38), which is different from a second gas deflection characteristic provided by the openable second wall opening (38) when the second wall opening (38) is opened.

5. A battery device (12) having a degassing channel (28) according to any one of claims 1 to 4, It is characterized by: The battery device (12) comprises a battery having at least one cell group, the at least one cell group comprising at least one battery cell (10) having an openable cell exhaust opening (26), wherein the exhaust duct (28) is arranged on the cell group such that the openable wall opening (38) of the first duct wall (30) is arranged opposite the associated cell exhaust opening (26).

6. The battery device (12) according to claim 5, It is characterized by: A battery cell (10) comprises a first side (14a) having two cell pole connections (16, 18) and a second side (14b) opposite the first side (14a) on which a cell exhaust opening (26) is arranged.

7. The battery device (12) according to claim 5 or 6, It is characterized by: The exhaust duct (28) is arranged on the cell group in such a way that the openable wall opening (38) of the first duct wall (30) has a predetermined distance (d) from the associated openable cell exhaust opening (26) in order to provide a free area (48) between the openable cell exhaust opening (26) and the openable wall opening (38).

8. The battery device (12) according to claim 5 or 6, It is characterized by: A partition wall (46) is arranged between the openable wall opening (38) and the associated openable cell exhaust opening (26), surrounding the openable wall opening (38) and the associated openable cell exhaust opening (26). The partition wall is an O-ring (46) and separates a free inner area (48) between the openable cell exhaust opening (26) and the openable wall opening (38) from an outer area between the cell group and the exhaust channel (28), the outer area being at least partially filled with a heat-conducting substance (44).

9. A motor vehicle having a battery arrangement (12) according to any one of claims 5 to 8.

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