Battery apparatus and method for venting gas from a battery cell

Abstract

The invention relates to a battery device (10) having a cooling wall assembly (18) comprising a cooling wall (20) and a battery cell (14) arranged at the cooling wall assembly (18) above the cooling wall assembly (18) with reference to a first direction (z), the battery cell comprising a battery cell core (16) having a first side (16a) with a releasable vent (16b) facing the cooling wall (20), the battery device (10) having a venting channel (26) into which a gas (28a, 28b) escaping from the vent (16b) can be conducted. The venting channel (26) is arranged below the releasable vent (16b) and above the cooling wall (20) with reference to the first direction (z) and is configured to enable a first portion (28a) of the gas (28a, 28b) which temporally first escapes from the vent (16b) to be conducted into the venting channel (26) in the event of the gas (28a, 28b) escaping from the vent (16b).

Description

Technical Field

[0001] This invention relates to a battery device for a motor vehicle, the battery device having a cooling wall assembly including a cooling wall, and at least one battery cell disposed on the cooling wall assembly and arranged above the cooling wall assembly with reference to a first direction, the battery cell including at least one battery cell. Here, the at least one battery cell has a first side with a releasable vent, the vent being releaseable to discharge gas from the at least one battery cell, wherein the battery device has a vent passage into which at least part of the gas escaping from the vent of the at least one battery cell can be guided. Here, the battery cell is disposed on the cooling wall assembly such that the first side of the at least one battery cell faces the cooling wall assembly. Furthermore, the invention also relates to a method for discharging gas escaping from the vent of the at least one battery cell of the battery device. Background Technology

[0002] In conventional batteries used in motor vehicles, especially high-voltage batteries (where ordinary prismatic battery cells are used, with the cell electrodes arranged on the upper side of the cell), the vent of such cells is usually also located on the upper side. Furthermore, a venting channel is typically provided, also located above the cell, and gas escaping from the releasing cell is guided into the venting channel. Here, this venting channel is usually part of a cell module or battery module having multiple battery cells arranged in a module housing. However, the venting channel can also be provided as an additional, separate component.

[0003] For example, DE 10 2013 216 071 A1 describes a current system having multiple galvanic cells and a venting device for discharging fluid escaping from one or more galvanic cells. Here, the venting device has an inflow opening for each cell, and each inflow opening is assigned a sealing element that prevents fluid from flowing out of the venting device through the inflow opening sealed by the sealing element. Here, the respective inflow openings of the venting device and their associated sealing elements can be integrated into the module cover of the battery module. Therefore, if gas leaves the cell and enters the venting device through the inflow opening, the gas correspondingly passes through the module cover.

[0004] Furthermore, it is known in the prior art that battery cells have a releasable vent on one side, which is not the side where the cell terminals are arranged. In this case, the side of the battery cell with the releasable vent can be facing a cooling device or cooling plate, and particularly the side arranged on such a cooling plate.

[0005] For example, DE 10 2017 212 223 A1 describes a battery having multiple energy storage cells, each cell having a casing opening sealed by a burst membrane. A cooling plate with a through-hole aligned with the casing opening is arranged between the cell casing and the cell venting chamber. In the event of cell venting, gas escaping from the cell can enter the cell venting chamber through the cooling plate. Simultaneously, coolant can enter the cell casing from the cooling plate.

[0006] Furthermore, DE 10 2019 118 905 A1 describes a cooling system for an energy storage device, having a cooling element with walls and a volumetric space defined by the walls through which coolant can flow. An opening is machined into the cooling element, at least partially separated from the volumetric space by the walls. An emergency opening device is provided to the opening, which opens under heat and / or pressure, thereby establishing a flow-guided connection between the volumetric space and the opening. Here, gas flowing from the battery cell can also be guided through the opening, through the cooling element, and discharged. Furthermore, coolant can be guided from the cooling element to the associated energy storage cell.

[0007] Furthermore, DE 10 2009 046 385 A1 describes a battery with a venting system having a substrate and at least one cell module disposed on the substrate. The cell module has at least one battery cell with a lower side having a vent. Here, the substrate has at least one opening leading to a collection area at the location of the vent, which may be limited by a housing wall on the lower side. The substrate may also be designed as a cooling plate, for example. Here, gas escaping from the battery cell is also guided through the cooling plate to the collection area. Here, the collection area may be partially integrated into the cooling plate as a recess on the side of the cooling plate opposite the battery cell.

[0008] Cooling plates, such as cooling base plates, are often also part of the battery casing, for example, the bottom of the battery casing. Because the battery casing should protect the housed cells from environmental influences, such as moisture or contaminant infiltration, it must be designed to be sealed. If gases escaping from the battery cells are to be discharged through a cooling plate, then either a permanent opening in the cooling plate would require additional protective casing walls, or the opening through the cooling plate would need to be designed with a very costly seal, which must ensure reliable opening during venting to prevent uncontrolled explosions of the equipment. Accordingly, venting gases through a cooling system is very costly.

[0009] Therefore, it is desirable to provide more efficient, simpler, and more reliable gas venting capabilities. Furthermore, another important aspect related to thermal runaway in battery cells is the detection of such thermal events, so as to, for example, warn vehicle drivers as early and reliably as possible and avoid false warnings. Additionally, it is desirable to be able to detect gas escape from the cell as easily and reliably as possible, and especially in advance. Summary of the Invention

[0010] Therefore, the object of the present invention is to provide a battery device and a method that can, as easily, efficiently and safely as possible, discharge gas escaping from the vent of the cell toward the cooling wall, and in particular, can, as reliably and in advance as possible, detect such gas escaping.

[0011] The battery device for a motor vehicle according to the present invention includes a cooling wall assembly comprising a cooling wall, and at least one battery cell disposed on the cooling wall assembly and arranged above the cooling wall assembly with reference to a first direction, the battery cell comprising at least one battery cell. Here, the at least one battery cell has a first side with a releasable vent, the vent being releasable for discharging gas from the at least one battery cell, wherein the battery device has a vent passage into which at least a portion of the gas escaping from the vent of the at least one battery cell can be guided. Furthermore, the battery cell is disposed on the cooling wall assembly such that the first side of the at least one battery cell faces the cooling wall assembly. Here, the vent passage is arranged below the releasable vent and above the cooling wall with reference to the first direction and is configured such that, in the event of gas escaping from the vent, a first portion of the gas that initially escapes from the vent can be guided into the vent passage.

[0012] Therefore, the portion of gas that escapes first in time is not directly guided through the cooling wall to the side of the cooling wall opposite the battery cell, but is at least first introduced into the exhaust channel arranged between the battery cell and the cooling wall, i.e., into the channel located on the same side of the cooling wall as the battery cell with the gas-releasing battery cell. Here, the invention is based on several insights: on the one hand, the invention utilizes the knowledge that the typical gas escape behavior of a battery cell can be divided into two escape stages, which differ significantly in the manner of gas escape. The first stage, which is very short in time, here primarily involves the first second of gas escape, especially the first few milliseconds. In this first stage of gas escape, typically only a very small amount of gas escapes at a relatively low gas escape velocity, while in the remaining second escape stage, a very large amount of gas (especially in the form of a gas particle stream) escapes from the exhaust port at a very high flow rate and high gas pressure. These two gas escape stages can now be advantageously used to achieve a novel two-stage gas exhaust process, which brings many advantages. Advantageously, the gas escaping in the first escape stage can be introduced into an exhaust channel between the battery cell and the cooling wall, based on its small quantity and low pressure. Here, although typically not a particularly large volumetric space is required, it is perfectly adequate to accommodate the gas escaping from the battery cell in the first escape stage. This gas escaping from the cell in the first escape stage is currently also referred to as the first portion of the gas. This first portion of the gas can advantageously be used, for example, to detect gas escape very early by means of a suitable sensor in the exhaust channel. Furthermore, this can be achieved in a particularly simple manner because the first portion of the gas can be dispersed in the exhaust channel, so that the corresponding sensor can be simply arranged somewhere in the exhaust channel. Thus, in the case of multiple cells, gas escape can also be detected by, for example, only one such sensor, regardless of which cell the gas escapes from. Furthermore, this exhaust channel, which can therefore be used to detect gas escape very early, can be used in a particularly cost-effective manner, as no additional components are required for this purpose. Only the cooling wall can be slightly modified, for example, in its configuration, to provide the exhaust channel, for example, by constructing a groove-shaped recess. The amount of gas escaping from the battery cell in the second escape stage is typically so high in pressure and heat that it can automatically penetrate the cooling wall opposite the exhaust port, much like a gas burner, and thus be discharged without the need for additional openings with seals in the cooling wall. The gas escaping in the second escape stage (hereafter referred to as the second portion of the gas) can therefore automatically create a path between the cooling wall assembly and the underbody protection device of the vehicle, for example, to enter a significantly larger gas containment volume. Therefore, no special construction of the cooling wall assembly is required, and the complex integration of openings with seals can be omitted.Conversely, if no venting channel is provided between the battery cell and the cooling wall, the vent of the battery cell is blocked by the cooling wall assembly, and there is a risk that the gas generated in the cell during the first escape phase is insufficient to create a path through the cooling wall assembly, which may subsequently lead to overvoltage in the cell and uncontrolled bursting of the cell. This can be advantageously avoided by providing a venting channel, i.e., directly below the vent and within the free space defined by the cooling wall on the lower side with reference to a first direction. Therefore, the present invention provides a particularly advantageous, and especially simple and inexpensive, gas venting management method.

[0013] The cooling wall preferably also forms the housing wall of the battery casing, in which the battery cells are housed. A battery device, preferably a high-voltage battery, is provided by the battery assembly. Thus, the battery assembly can, for example, serve as a power battery for a motor vehicle. In addition to the cooling wall, the cooling wall assembly may also have other elements, particularly other layers, such as spacers or spacer fillers, i.e., thermally conductive materials, or typically a thermal interface layer, through which a good thermal connection between the battery cells and the cooling wall can be provided, for example, by sealing or preventing possible gaps or cavitation between the battery cells and the cooling wall. In the area of ​​the venting passage, such a thermal interface layer can be interrupted or omitted. Therefore, such a thermal interface layer can be arranged, for example, only in the area between the battery cells and the cooling base plate where no venting passage is provided. Preferably, such a thermal interface layer connects the corresponding area of ​​the battery cell to the cooling wall. Thus, the battery cell is locally and directly connected to the cooling wall through this thermal interface layer. For example, the battery cell may comprise only at least one battery cell, i.e., the battery cell is said at least one battery cell. However, preferably, the battery cell is a battery module having multiple battery cells, which can also be referred to as a cell module, and may, for example, have an additional module housing in which the battery cells of the battery module are arranged. In this case, the module housing also has an opening in the area of ​​the exhaust port of at least one battery cell. Therefore, in the area of ​​the exhaust port, a free area provided by the exhaust channel is provided between the exhaust port and the cooling wall, in which neither a thermal interface layer nor part of the module housing is arranged. Furthermore, the battery cell is arranged above the cooling wall assembly with a first direction as a reference. This means that the current terms "above" and "below," and the directional terms derived therefrom, are always based on the first direction. For example, when the battery device is conventionally arranged in a motor vehicle, if the first direction, for example, points towards the vehicle's vertical axis, then the battery cell is actually located above the cooling wall assembly; if the first direction, for example, is oriented opposite to the vehicle's vertical axis, then the cooling wall assembly is actually located above the battery cell. In other words, the cooling wall can be, for example, a cooling base plate or a cooling cover. In principle, the spatial orientation of the battery device is independent of its function. However, it is particularly advantageous that the cooling wall assembly is positioned below the battery cell relative to the conventional mounting location of the battery equipment in the vehicle, and can accordingly provide gas exhaust downwards, for example, towards the undercarriage protection device. Therefore, the gas is exhausted away from the passenger compartment, thereby further improving safety. This also significantly and more effectively resists heat generation in the passenger compartment. The battery cell can be constructed, for example, as a lithium-ion cell. Furthermore, the battery cell can, in principle, have any geometry, and can be constructed, for example, as a prismatic cell, a circular cell, or a pouch cell. In this case, it proves particularly advantageous to construct the battery cell as a prismatic cell.The cell electrodes of such a battery cell are preferably arranged on a side of the battery cell different from the first side. Preferably, the cell electrodes (also referred to as cell terminals) are arranged on opposite sides of the battery cell, which define the battery cell perpendicular to the first direction. For example, the cell electrodes can be arranged on opposite sides of the battery cell with a second direction as a reference. The second direction is preferably perpendicular to the first direction. Since the cell electrodes are arranged on the side of the cell housing of the battery cell, rather than on the upper and / or lower side of the cell, and especially not on the first side where the vent is arranged, a significantly simpler decoupling of the HV (high voltage) path from the outflowing gas can also be provided. If the battery cell comprises multiple battery cells in the form of a battery stack, these multiple battery cells are preferably arranged side by side in a third direction, which is perpendicular to both the first and second directions. In this case, the venting channel also preferably extends in a third direction. Thus, the venting channel can be advantageously guided along the vent of the corresponding battery cell of the battery module.

[0014] Accordingly, an advantageous design of the invention is that the battery cell comprises a plurality of battery cells, each having a first side with a releasable vent, wherein an vent passage passes through each vent. Thus, gas escaping from the respective cell, and in particular at least a first portion of gas escaping from the associated cell, can be introduced into the same vent passage. In other respects, the battery cells can be constructed identically. The example explained in more detail below (which relates to at least one battery cell) is therefore also entirely similarly applicable to multiple battery cells in the same manner. The vent passage thus forms a cavity extending through the respective vents of the plurality of battery cells in the battery cell. The vent passage can even extend through the vents of the cells in different battery cells. Therefore, the battery device can also accordingly have a plurality of battery cells, each having a plurality of battery cells. Here, the vent passage can extend in principle in a straight line or in a curved manner. Furthermore, multiple vent passages can be provided, which can be fluidly separated or fluidly coupled to each other. In the latter case, the vent passage can therefore also be provided as a branched vent passage system. The following detailed examples of exhaust passage implementation should also be applied very similarly to other alternative exhaust passages.

[0015] For example, such an exhaust channel can be provided in a simple manner by pressing / processing the exhaust channel into / into a flat cooling plate that provides the cooling wall. Thus, a groove-shaped recess is provided in the cooling wall below the exhaust port of at least one cell. Accordingly, another particularly advantageous design of the invention is that the cooling wall is constructed with a groove-shaped recess in a first direction to provide the exhaust channel, wherein the portion of the cooling wall with the recess constitutes a channel wall defining the exhaust channel. Thus, such an exhaust channel can be manufactured very simply and without the need for additional components. The exhaust channel can therefore be simply pressed into the provided cooling plate. This additionally provides space, which serves as the exhaust channel. Here, the recess can extend longitudinally in a direction perpendicular to the first direction. This has the advantage that the exhaust channel can also easily pass below other exhaust ports of other cells. Therefore, the exhaust channel can be shared by multiple cells.

[0016] Furthermore, in the following text, any reference to gas escaping from the cell or its vent should always refer to the situation of gas escaping from the cell, which will also be referred to as cell venting in the following text.

[0017] In another advantageous embodiment of the invention, the cooling wall is constructed as a cooling plate through which a coolant can flow. Such a cooling plate provides particularly effective cooling of the battery cell during normal operation. Therefore, cooling channels can extend within the cooling plate, through which a coolant, such as a water-glycol mixture, can be guided. Preferably, no cooling channels are present in the portion of the cooling wall directly below the exhaust port and thus part of the channel wall of the exhaust channel.

[0018] In another advantageous embodiment of the invention, the cooling wall has a region that provides a portion of the channel wall for exhaust passage, wherein the battery device has an electrically insulating protective layer disposed at least in said region of the cooling wall, and this protective layer is particularly different from a plastic film. With such a protective layer, the temperature resistance of the region of the cooling wall to which the protective layer is disposed can be advantageously improved. This has the significant advantage that the airflow escaping from the cell can be controlled to burn through the cooling wall, so that a second portion of the gas escaping from the cell can be particularly exhausted, as has been described above, for example. It is precisely this protective layer, such as a coating or fabric material, on the cooling plate or cooling wall that typically enables entirely novel exhaust management. For example, the material properties of the protective layer can be utilized specifically, and the thickness of the protective layer can be set and determined specifically to determine when the gas escaping from the cell burns through the cooling wall. Here, this protective layer should be understood as a layer different from a plastic film. The background to this is that plastic films are typically disposed on cooling plates for electrical insulation to ensure safe electrical separation from the battery module or battery cell. Here, such plastic films do not significantly improve the temperature resistance of the cooling wall. Therefore, the protective layer of electrical insulation should be understood as the layer that makes the area in which it is located significantly more resistant to airflow escaping from the battery cell compared to a thin plastic film.

[0019] Here, while the entire wall of the exhaust channel provided by the cooling wall does not need to be covered with such a protective layer, it is still possible. It is also conceivable, for example, to place such a protective layer only locally in the area of ​​the exhaust channel wall directly opposite the exhaust port of the battery cell. There, the temperature effect caused by the airflow escaping from the battery cell is greatest. Such a protective layer therefore has a significant advantage in that it can delay the burn-through of the cooling wall in the area where the protective layer is located. This allows for a significantly simpler and more reliable implementation, where sufficient gas can first enter the exhaust channel to be guided, for example, to a suitable collection point where a fire sensor is placed to detect gas escape in advance and reliably.

[0020] Furthermore, it is particularly advantageous that the protective layer is constructed as a coating or a fabric layer for the area. Particularly advantageous are protective layers comprising KTL coatings, i.e., cathode impregnation coatings and / or ceramic layers. Very high temperature resistance can be achieved, especially with ceramic layers. However, KTL coatings are also well-suited for targeted control of burn-through behavior in the area. Moreover, this can be achieved with KTL coatings in a significantly less expensive manner compared to ceramic layers. Additionally, various fabric layers made of heat-resistant fibers, such as synthetic fibers (Kevlar) or glass fibers, are also considered as protective layers. However, it is preferable that the protective layer is constructed as a coating because the protective layer can be provided significantly thinner and correspondingly requires less structural space.

[0021] In another highly advantageous embodiment of the invention, the cooling wall has a failure region that provides a portion of the channel wall for the exhaust passage. This failure region is arranged directly below the exhaust port with reference to a first direction and is configured such that, upon gas escaping from the exhaust port, based on the escape of a second portion of the gas, distinct from the first portion, and particularly upon the arrival of this second portion of the gas at the failure region, the failure region releases an opening through which it penetrates the cooling wall in the first direction. Thus, the second portion of the gas exits the exhaust port after the first portion in time. As described at the outset, this second portion of the gas escapes at a significantly higher pressure and also provides a significantly larger volume than the first portion. Consequently, particularly with the corresponding configuration of the failure region, it is possible to achieve that the failure region fails upon the arrival of the second portion of the gas, automatically releasing the opening through which the escaping gas can penetrate the cooling wall and thus exit from the battery casing.

[0022] Therefore, the cooling wall does not need to be constructed with separately provided openings sealed by closures or complex valve devices constructed in other ways. The channel wall can simply be constructed with a suitable material and / or thickness in the failure area, so that the channel wall can be easily penetrated by the gas when the second part of the gas arrives. Preferably, the cooling wall is constructed of aluminum, especially of aluminum sheet, and has a wall thickness of, for example, a few millimeters, for example, between 1.2 mm and 1.5 mm. In the region of the cooling channel, the cooling wall can, for example, have a thickness of 10 to 15 mm. Here, the cooling wall can also have multiple such aluminum sheet layers.

[0023] Here, the failure zone does not necessarily have to fail immediately when the gas escaping from the cell reaches it. This can also be controlled in a targeted manner by setting up the aforementioned protective layer.

[0024] Accordingly, another highly advantageous design of the invention is that the area where the protective layer is disposed has at least the aforementioned failure area. In other words, at least the failure area should be provided with such a protective layer. However, the entire channel wall of the exhaust passage provided by the cooling wall can also be provided with such a protective layer. In both cases, the burn-through behavior of the channel wall of the exhaust passage provided by the cooling wall can be specifically set and determined by the protective layer.

[0025] In another highly advantageous embodiment of the invention, the exhaust passage is configured such that a first portion of the gas can be guided to a collection area of ​​the exhaust passage, where a fire sensor is arranged, and / or a releasable opening is arranged in the portion of the cooling wall that defines the exhaust passage in the collection area for discharging the first portion of the gas from the exhaust passage, particularly wherein the opening can be released according to pressure.

[0026] It is advantageous to detect the first portion of gas escaping from the battery cell using a fire sensor. Various physical detection principles can be used for this purpose, such as detecting temperature, pressure, and / or gas composition. Combinations of these are also conceivable. If the first portion of gas escaping from the battery cell is detected by the fire sensor, a warning message can be immediately output to the driver, and / or the battery system can be disconnected, for example, in applications involving motor vehicles. This allows for very early intervention. Detection of the escaping gas has a significant advantage here, namely, that, compared to, for example, detecting voltage disturbances in the battery cell, detection of the escaping gas can definitively infer a particularly critical state of the cell and thermal runaway. Conversely, voltage disturbances in the cell may have multiple causes and are not necessarily attributed to thermal runaway. Guiding the gas to a collection point can be achieved automatically, for example, by having a closed exhaust channel. The gas is then dispersed accordingly in the exhaust channel and thus automatically reaches the collection area.

[0027] If the internal pressure in the exhaust passage exceeds a preset limit, a releasable opening in the exhaust passage can automatically open, thereby releasing the gas located in the exhaust passage. The releasable opening in the exhaust passage ensures the necessary pressure balance. Such a releasable opening in the exhaust passage (especially if it is located within a portion of the cooling wall) can be simply constructed as a bursting film or a rated break point implemented in other ways in the cooling wall, or it can be constructed as an overpressure valve, etc. It is also sufficient, for example, to provide only one such collection area or only one such releasable opening in the cooling wall. Conversely, the aforementioned failure areas can be distributed throughout the entire exhaust passage, or automatically generated at the location where the corresponding cell releases gas, since the failure area is the area of ​​the cooling wall directly opposite the exhaust port.

[0028] Advantageously, the exhaust channel can be integrated into the cooling plate, particularly in the intermediate space between the cooling plate and the battery cell itself. This intermediate space can be used to receive and detect, for measurement purposes, the first temporal portion of the gas escaping from the cell. Thus, the exhaust channel provides free space for the outflowing gas below the ventilation element (i.e., the exhaust port). Depending on the exhaust management, the cooling plate area of ​​the exhaust channel can be coated with a coating or fabric material. This allows control over when the cooling plate can be burned through by the airflow from the cell. This enables, for example, exhaust management where, through the coating or fabric material, the initial amount of gas released is guided through the exhaust channel to a collection point within the first few milliseconds, where it can then activate a fire sensor. The remaining gas, referred to here as the second portion of the gas, flowing from the cell in the following seconds, then correspondingly burns through the cooling plate, and the gas can fill the space between the cooling plate and, for example, a vehicle underbody protection device located below. It is precisely in this area between the cooling plate and the underbody protection device that a particularly large volumetric space is provided, which can be used to reduce the risk of gas accumulation, thereby reducing the pressure in the battery system, distributing the gas over a large area under the battery, and thus lowering the gas temperature. This reduces the likelihood of the gas igniting. Finally, the gas from this volumetric space between the cooling plate or cooling wall and the underbody protection device can be discharged from the vehicle at an appropriate venting point.

[0029] Furthermore, motor vehicles equipped with the battery device or one of the designs according to the present invention should also be considered as belonging to the present invention.

[0030] The motor vehicle according to the invention is preferably designed as an automobile, especially a car or van, or a bus or motorcycle.

[0031] Furthermore, the present invention relates to a method for discharging gas escaping from a releasable vent of at least one battery cell in a battery device, wherein the battery device includes a battery cell having at least one battery cell, and wherein the battery cell is arranged on a cooling wall assembly having a cooling wall, and is arranged above the cooling wall assembly with respect to a first direction such that a first side of the battery cell having a releasable vent faces the cooling wall assembly. Here, a first portion of the gas that first escapes from the vent in time is introduced into an exhaust channel, which is arranged below the releasable vent and above the cooling wall with respect to the first direction.

[0032] The advantages described for the battery device and its design according to the invention are applied in the same manner to the method according to the invention.

[0033] The present invention also includes improvements to the method according to the invention, which have features already described in conjunction with improvements to the battery device according to the invention. Therefore, corresponding improvements to the method according to the invention will not be described here.

[0034] The present invention also includes combinations of features of the described embodiments. Therefore, the present invention also includes implementations having combinations of features of multiple embodiments described, unless these embodiments are described as mutually exclusive. Attached Figure Description

[0035] Embodiments of the present invention are described below. Therefore: Figure 1 A schematic cross-sectional view of a battery device according to an embodiment of the present invention is shown during the first stage of gas escaping from the cell; and Figure 2 This shows the second stage of gas escape. Figure 1 A schematic diagram of the battery device. Detailed Implementation

[0036] The embodiments described below are preferred embodiments of the present invention. In the embodiments, the components described in the embodiments represent various features of the invention that are considered independent of each other, and these features also independently improve the invention. Therefore, this disclosure is also intended to include combinations different from the combinations of features shown in the embodiments. Furthermore, the described embodiments may be supplemented by other features of the invention that have already been described.

[0037] In the accompanying drawings, the same reference numerals denote elements that have the same function.

[0038] Figure 1A schematic diagram of a battery device 10 according to an embodiment of the present invention is shown. The battery device 10 here has battery cells in the form of a battery module 12. The battery module 12 (also referred to as a cell module 12) here includes a module housing 14 in which a plurality of battery cells 16 are arranged. These battery cells 16 are arranged side-by-side with respect to the y-direction shown here, such that only one such battery cell 16 can be seen in the current cross-section. In this example, the battery cell 16 is constructed as a prismatic cell 16. Here, such a battery cell 16 includes a first side 16a, which represents the lower side 16a of the cell 16 relative to the z-direction shown. Furthermore, the cell 16 includes a releasable vent 16b arranged on the lower side 16a of the cell 16. Preferably, the battery device 10 is configured for arrangement in a motor vehicle, according to which the battery device 10 is oriented in the z-direction shown here toward the vertical axis of the vehicle. However, it is also conceivable that the battery device 10 is arranged in a motor vehicle such that the z-direction shown here is oriented opposite to the vehicle height direction. Furthermore, cell 16 includes two cell electrodes 16c and 16d, which are arranged on opposite sides of cell 16, particularly on the second side 16e and the third side 16f of cell 16. This advantageously allows for easier decoupling of the high-voltage path from the gas escaping from cell 16 during venting. Furthermore, in this way, cell 16 or battery module 12 as a whole can be cooled on both sides, i.e., from above and below, by corresponding cooling devices. In this example, cooling of the lower side of battery module 12 is achieved by a cooling wall assembly 18, which is part of battery device 10. This cooling wall assembly 18, more precisely, in this example, has a cooling wall 20, constructed as a cooling plate 20, which may have cooling channels (not shown) through which coolant can flow. Cooling wall 20, for example, can provide a cooling base plate for the battery housing of battery device 10. In other words, cooling wall 20 simultaneously constitutes the outer wall, particularly the base plate, of the battery housing that houses battery modules 12, preferably multiple such battery modules 12. Alternatively or additionally, the cooling wall 20 may also be arranged above the battery module 12, for example. The battery module 12 is further thermally connected to the cooling wall 20 via a thermal interface layer 22, which is part of the cooling wall assembly 18. The thermal interface layer 22 may be provided, for example, in the form of a gap filler, i.e., a thermally conductive material that fills gaps, or in the form of a so-called gap pad. Currently, a vehicle underbody protection device 24 for a motor vehicle using the battery device 10 is arranged below the cooling wall 20. The module housing 14 also has an opening 14a in the area of ​​the vent 16b, which is closed by a base membrane in the cell housing preferably configured as a cell 16.

[0039] The cooling device 20 is now advantageously configured to provide free space 26 directly below the exhaust port 16b, serving as an exhaust channel 26. This exhaust channel is thus located between the cooling wall 20 and the battery cell or battery module 12. The exhaust channel 26 may have a width along the x-direction corresponding to the width of the opening 14a in the module housing 12. Accordingly, the exhaust channel 26 is bounded in the z-direction by the exhaust port 16b, and, where appropriate, by a portion of the first side 16a of the battery cell. Opposite to the z-direction, the exhaust channel 26 is bounded by the cooling wall 20. Along the x-direction and opposite to the x-direction, the exhaust channel 26 is here bounded by the end side of the module housing 14 defining the module housing opening 14a, the end side of the thermal interface layer 22, and again by a portion of the cooling wall 20. This exhaust channel 26 can, for example, be provided in a simple manner by being pressed into the sheet metal component of the cooling plate 20 during its manufacture. Here, the cooling plate 20 is preferably made of aluminum. However, in principle, other preferred metal materials can be considered. For example, during the manufacture of the cooling plate 20, the shape of the exhaust channel 26 is pressed into the plate component of the cooling plate. Thus, a free space 26 for the outflowing gas is created below the ventilation element (i.e., the releasable exhaust port 16b of the cell 16).

[0040] The outflowing gas is Figure 1 The current text is shown via arrow 28a. Figure 1 Specifically illustrated here is the battery device 10 during the first gas escape phase in the event of a thermal event at cell 16. During this first gas escape phase, typically only a small amount of gas escapes from cell 16 at a typically very low gas pressure. This first gas escape phase is typically limited to the first second of gas escape and typically lasts only a few milliseconds. This is followed by a typical second gas escape phase, in which a large amount of gas escapes from vent 16b at extremely high gas pressure and extremely high temperature within a very short time, which will be discussed later. Figure 2Detailed Explanation. This invention now uses this knowledge to provide so-called two-stage gas venting management or exhaust management. The first temporal portion 28a of the escaping gas can now be advantageously used, for example, to provide particularly early detection of the gas escaping. Thus, the gas 28a escaping in the first escaping stage can be guided, for example, through exhaust passage 26 to collection area 30, where, for example, a fire sensor 32 is arranged. Furthermore, in this area 30, or in principle, at any other location in exhaust passage 26, a releasable opening 34, in the form of, for example, a bursting element, can be provided, particularly through an area of ​​cooling wall 20, which is also part of the passage wall of exhaust passage 26. This exhaust passage can, for example, be passively opened when the pressure within exhaust passage 26 exceeds a certain value, and thus pressure equalization can be ensured. In this example, the fire sensor 32, the effective emission range 30, and the releasable opening 34 are arranged below the exhaust port 16b of cell 16, but this is not mandatory. These elements can, in principle, be located at any other location in exhaust passage 26, particularly relative to the y-direction shown here.

[0041] As described, since the cooling wall 20 is preferably provided only by thin aluminum plate components, it is advantageous that at least one region 20a of the cooling wall 20 has a protective layer 36, which can be constructed as a coating or a layer of fabric material, to ensure that the cooling wall 20 does not burn through prematurely in the region of the exhaust channel 26 when gas 28a escapes. This protective layer 36 improves the temperature resistance of region 20a of the cooling base plate or cooling wall 20, and thereby controls when the cooling plate 30 can burn through. Therefore, burn-through of the cooling wall 20 in region 20a preferably occurs only when the escaping gas 28a has been successfully detected by the fire sensor 32. Here, region 20a at least includes the area of ​​the cooling wall 20 directly below the corresponding exhaust port 16b. Therefore, the gas 28a escaping from the exhaust port 16a reaches the coating or protective layer 36. However, the protective layer 36 can also extend over the entire wall region of the cooling wall 20 that restricts the exhaust channel 26. Here, the burn-through behavior can be determined by the choice of material and thickness of the protective layer 36, especially its thickness in the z-direction.

[0042] Figure 2 The second gas escape phase is shown. Figure 1A schematic diagram of the battery device 10. During this second gas escape phase, as described above, a significantly larger volume of gas with a significantly higher gas pressure escapes from the exhaust port 16b. The escaping gas flow 28b (also referred to within the scope of this invention as the second portion 28b of the gas escaping from the cell 16) now burns through the cooling wall 20, particularly in the failure region 38 located directly below the exhaust port 16b. This failure region 38 is also the region where the protective layer 36 is disposed, wherein, as described, the protective layer 36 may also extend over other regions of the cooling wall 20, which also provide part of the channel wall of the exhaust passage 26. Therefore, no special construction of the cooling base plate 20 is required for the cooling wall 20 to be able to burn through by the gas flow 28b. However, it is advantageous to have a coating 36 on region 20a of the cooling wall 20 or to provide a protective layer 36 in region 20a, because this allows control and determination of when the cooling wall 20 should be burned through and the opening 40 in the cooling base plate or cooling wall 20 to be released.

[0043] The module housing 14 and the cell housing of the cell 16 are preferably made of aluminum. The protective layer 36 is made of an electrically insulating material. Preferably, the protective layer 36 is provided with a KTL coating or a ceramic coating.

[0044] This allows for an advantageous expansion of the functionality of the cooling plate 20 via the exhaust channel 26. By integrating multiple functions into a single component, namely the current cooling plate 20, the number of battery components is reduced, and thus the battery weight is lowered. Novel exhaust management can be achieved by applying a coating or using fabric materials on the cooling plate 20. Gas 28a escaping from the cell 16 in the first few milliseconds can be introduced into the exhaust channel 26 and directed to the collection area 30, where a fire sensor 32 can be installed to detect gas escaping from the cell 16. A bursting diaphragm 34 or an overpressure valve may also be present there to provide pressure equalization in the event of overpressure in the exhaust channel 26. In the second stage of gas escape, the escaping gas 28b subsequently burns through the cooling base plate 20 and thus escapes into the intermediate region 42 between the underbody protection device 24 and the cooling base plate 20. Gas 28b can be discharged from this region 42, for example, after passing through various gas steering structures, from the vehicle. The space 42 between the cooling plate 20 and the underbody protection device 24 helps to prevent gas accumulation after the battery cell 16 is vented. In the case of a large battery cell 16, the amount of gas is correspondingly higher, and therefore the risk of gas accumulation is greater; this accumulation can now be actively counteracted. Gas accumulation is thus prevented, and the gas is dispersed over a large area below the battery provided by the battery device 10, thereby reducing the pressure in the battery system and lowering the temperature of the gas 28b. This also reduces the likelihood that the gas 28a will ignite when escaping from the vehicle.

[0045] In summary, the embodiments illustrate how the present invention can provide a coated exhaust passage integrated into a cooling plate to provide novel exhaust management.

Claims

1. A battery device (10) for use in a motor vehicle. - in, The battery device (10) has a cooling wall assembly (18) including a cooling wall (20). - At least one battery cell (14) disposed on the cooling wall assembly (18) and disposed above the cooling wall assembly (18) with reference to a first direction (z), the battery cell comprising at least one battery cell (16). - Wherein, at least one battery cell (16) has a first side (16a) having a releasable vent (16b) that can be released to discharge gas (28a, 28b) from at least one battery cell (16). - The battery device (10) has an exhaust channel (26) in which, when gas (28a, 28b) escapes from the exhaust port (16b) of at least one battery cell (16), the escaped gas (28a, 28b) can be at least partially introduced into the exhaust channel. - wherein the battery cell (14) is arranged on the cooling wall assembly (18) such that the first side (16a) of at least one battery cell (16) faces the cooling wall assembly (18). The exhaust passage (26) is characterized by being arranged with reference to a first direction (z) below the releasable exhaust port (16b) and above the cooling wall (20), and is configured such that when gases (28a, 28b) escape from the exhaust port (16b), the first portion (28a) of the gases (28a, 28b) that escapes from the exhaust port (16b) in time can be introduced into the exhaust passage (26). The cooling wall (20) has a failure area (38). - This failure area provides part of the channel wall of the exhaust passage (26), - The failure area is located directly below the exhaust port (16b) with the first direction (z) as the reference. - The failure region is constructed such that, in the event of gas escaping from the exhaust port (16b), the failure region releases an opening (40) through the first direction (z) of the cooling wall (20) by means of the second part (28b) of the gas (28a, 28b) which is different from the first part (28a) of the gas.

2. The battery device (10) according to claim 1, characterized in that, The cooling wall (20) is constructed as a cooling plate (20) through which coolant can flow.

3. The battery device (10) according to claim 1 or 2, characterized in that, The cooling wall (20) has a region (20a) of a portion of the channel wall that provides an exhaust passage (26), wherein the battery device (10) has an electrically insulating protective layer, which is different from a plastic film, disposed at least on the region of the cooling wall (20) that provides the exhaust passage (26).

4. The battery device (10) according to claim 3, characterized in that, The protective layer (36) is constructed as a coating or a fabric layer of the region (20a) of the channel wall that provides a portion of the exhaust passage (26), and the protective layer (36) includes a KTL coating and / or a ceramic layer.

5. The battery device (10) according to claim 1, characterized in that, The area (20a) with the protective layer (36) has at least the failure area (38).

6. The battery device (10) according to claim 1 or 2, characterized in that, The exhaust passage (26) is configured such that a first portion of the gas (28a, 28b) can be guided to the collection area (30) of the exhaust passage (26). - Fire sensors (32) are installed in the collection area; and / or - A releasable opening (34) is provided in the portion of the collection area that is within the defined exhaust passage (26) of the cooling wall (20) for discharging a first portion of the gas (28a, 28b) from the exhaust passage (26), the opening (34) being capable of being released according to pressure.

7. The battery device (10) according to claim 1 or 2, characterized in that, The battery cell (14) has a plurality of battery cells (16), each battery cell having a first side (16a) having a releasable vent (16b), wherein a vent passage (26) passes through each vent (16b).

8. The battery device (10) according to claim 1 or 2, characterized in that, The cooling wall (20) is constructed with a groove-shaped recess in the first direction (z) to provide an exhaust passage (26), wherein the portion of the cooling wall (20) having the recess constitutes a passage wall defining the exhaust passage (26).

9. The battery device (10) according to claim 1, characterized in that, The failure region is constructed such that, when gas escapes from the exhaust port (16b), the second part (28b) of the gas (28a, 28b) reaches the failure region, which releases an opening (40) through the cooling wall (20) in the first direction (z).

10. A method for discharging gases (28a, 28b) escaping from a releasable vent (16b) of at least one battery cell (16) of a battery device (10), wherein, The battery device (10) includes a battery cell (14) having at least one battery cell (16), wherein the battery cell (14) is arranged on a cooling wall assembly (18) having a cooling wall (20) and is arranged above the cooling wall assembly (18) with reference to a first direction (z), such that a first side (16a) of the battery cell (16) having a releasable vent (16b) faces the cooling wall assembly (18), characterized in that a first portion (28a) of gas (28a, 28b) that first escapes from the vent (16b) in time is introduced into an exhaust channel (26), which is arranged below the releasable vent (16b) and above the cooling wall (20) with reference to the first direction (z). The cooling wall (20) has a failure area (38). - This failure area provides part of the channel wall of the exhaust passage (26), - The failure area is located directly below the exhaust port (16b) with the first direction (z) as the reference. - The failure region is constructed such that, in the event of gas escaping from the exhaust port (16b), the failure region releases an opening (40) through the first direction (z) of the cooling wall (20) by means of the second part (28b) of the gas (28a, 28b) which is different from the first part (28a) of the gas.

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