HV battery with at least one expandable and / or flexible pouch degassing device

Abstract

In various embodiments, there is provided an HV battery (2) comprising: at least one battery module (3) having a degassing valve or degassing opening; a degassing device (4) coupled to the degassing valve or the degassing opening and configured to dissipate gas (6) exiting the battery module (3) in the event of damage; wherein the degassing device (4) comprises at least one deployable and / or flexible bag (5) coupled to an outlet of the degassing device (4). Furthermore, an electric vehicle (1) comprising an HV battery (2) and the use of the deployable and / or flexible pouch (5) according to the invention are provided.

Description

Technical Field

[0001] The invention relates to an HV battery with a degassing device having at least one deployable and / or flexible bag. The invention also relates to an electric vehicle equipped with an HV battery and the use of at least one deployable and / or expandable bag according to the invention. Background Art

[0002] HV batteries, especially traction batteries in electric vehicles, usually include a plurality of battery modules in which a plurality of battery cells are sequentially arranged and electrically connected to each other. Lithium-ion batteries are most commonly used as battery cells.

[0003] During the operation of an HV battery, a number of destructive events can cause one or more of the cells to heat to a temperature above their specified operating range, resulting in cell degassing. Such destructive events include, for example, a short circuit between the electrodes of the cell, excessive charging current or high ambient temperature during charging, possibly accompanied by a high charge or discharge load on the battery. Overheating of the cell can trigger unwanted chemical reactions in the cell, which can lead to so-called thermal runaway. In particular, the electrolyte within the closed cell decomposes and becomes gaseous, which can cause a sharp increase in pressure within the sealed cell in a relatively short period of time. If no countermeasures are taken, the cell may burst, which can damage not only the affected cell, but also adjacent cells.

[0004] In order to prevent the battery cells from bursting, a safety valve is usually provided, which opens when the limit pressure is reached inside the battery cell, thereby allowing the pressure inside the battery cell to be reduced in a controlled manner. Then, the hot gas first flows inside the corresponding battery module and can be buffered therein. If the limit pressure is exceeded inside the battery module, the safety valve of the battery module opens, and the hot gas is discharged to the external environment through the degassing device to prevent the battery module or battery from bursting.

[0005] From publication DE 10 2021125189 A1 a degassing device with a cell degassing channel is known for removing gases from a motor vehicle battery comprising at least one battery cell, wherein hot gases exiting during thermal runaway of the battery cell are conveyed via the degassing device to the rear region of the electric vehicle in order to be discharged there to the external environment. According to the publication, the gases to be removed are thereby directed to non-critical regions of the motor vehicle, i.e. regions known in combustion vehicles for harmful gases to reach the external environment from the vehicle.

[0006] Publication DE 10 2021208376A1 discloses a battery system and a device for degassing and / or cooling and / or extinguishing a battery system of a vehicle, the device having at least one duct element, wherein the duct element comprises a hose which is arranged rolled up in the vehicle in the transport state. In addition, at least one activation device is provided, by which the duct element can be brought into a useful state protruding from the vehicle as required. By means of the duct element, hot gases can be discharged at a location spaced apart from the vehicle and / or an extinguishing agent for cooling and / or extinguishing a fire of the battery system can be introduced from a location spaced apart from the vehicle. Summary of the invention

[0007] In view of this, it may be seen as an object of the present invention to provide a traction battery which reduces the likelihood of injury to personnel from hot gases leaving the battery module during thermal runaway.

[0008] This object is achieved by the subject matter described below. Further preferred embodiments can also be found below.

[0009] According to the invention, a HV battery is provided, comprising at least one battery module having a degassing valve or a degassing opening, and a degassing device coupled to the degassing valve or the degassing opening and configured to discharge gas leaving the battery module in the event of damage. The degassing device comprises at least one deployable and / or flexible bag coupled to an outlet of the degassing device. In the context of the invention, the bag may be a hose.

[0010] The expandable and / or flexible bag is folded and / or compressed in its normal state and / or inactivated state. The expandable bag or hose can be a rolled bag or a rolled hose (which can also be flexible). During thermal runaway, the hot gas leaving the battery module is guided into the bag through the degassing device. As a result, the pressure inside the bag increases, causing it to expand and / or expand. The hot gas leaving the battery module is collected in the bag. The bag can be made of a material with a very low thermal conductivity so that its surface can only be heated slowly. In general, the risk of personal injury can be minimized by controlling the collection of hot gas in the expanded and / or expanded bag. The material of the bag can also be heat-resistant. In another embodiment, the bag can be made of a material with a very high thermal conductivity so as to absorb the heat of the hot gas and effectively dissipate it into the environment, thereby minimizing the reactivity of the gas.

[0011] Expanding the bag may refer to the bag being mechanically expanded, wherein folds or collapsed portions of the bag surface are expanded, thereby increasing the internal volume defined by the bag. The expansion of the bag may refer to an increase in its internal volume due to the elasticity of the bag material. In particular, the bag expands when the pressure inside the bag is higher than the pressure outside the bag.

[0012] The dimensions of the bag, in particular its internal volume, can be matched to the battery or to the amount of escaping gas to be expected during thermal runaway of the battery cell. At least one bag can be arranged in an inactive and therefore compact or collapsed state at the outlet opening of the degassing device. During a thermal event, the hot gas is used to unfold and / or expand the bag. The hot gas is then stored in the at least one bag and cannot cause further property damage, personal injury or ignite other objects. As a result, the gas does not reach the environment and can be transported away and disposed of in the bag in a defined manner.

[0013] According to other embodiments of the HV battery, the degassing device may include a duct system. The duct system may be designed differently and adapted to the design of the HV battery. Thus, the duct system may include a chamber connected to the degassing valve of the battery module. The chamber may act as a buffer and first collect the hot gases leaving the battery module. The duct system with or without an intermediate chamber may provide a connection between the degassing valve of the battery module and the inlet into at least one bag.

[0014] According to other embodiments of the HV battery, the bag may include a pressure relief valve or a defined opening. The pressure relief valve may act as a safety valve to prevent the bag from bursting uncontrollably. It may be configured to open in a controlled manner when a limit pressure is reached to reduce the pressure within the unfolded and / or expanded bag. If the pressure drops below a second limit pressure, the pressure relief valve may be closed again to limit the amount of hot gas released to the external environment to as low a level as possible.

[0015] According to other embodiments of the HV battery, the pressure relief valve can be arranged on the bag so that the pressure relief valve is arranged on its top side in the unfolded and / or expanded state of the bag. The top side of the bag can correspond to the surface of the bag which, when the degassing device is installed in the electric vehicle, faces upward (i.e., toward the sky) or faces away from the parking ground.

[0016] According to the invention, there is also provided an electric vehicle comprising the aforementioned HV battery, wherein in the electric vehicle, the degassing device is arranged with a deployable and / or flexible bag coupled thereto, such that the bag protrudes from the body of the electric vehicle in the deployed and / or expanded state. For this purpose, an opening can be provided in the body through which the bag can be deployed and / or expanded outwardly, i.e. deployed and / or expanded from the body.

[0017] According to other embodiments of the electric vehicle, the deployable and / or flexible bag can be constructed so that in the event of damage it protrudes from the vehicle body due to the gases leaving the degassing device, so that the pressure relief valve is arranged on its top side. The top side can correspond to the bag surface facing the sky or away from the earth's surface. This means that, in the event of controlled venting of the bag, the hot gases can flow out in a direction away from the vehicle and possibly away from people standing nearby.

[0018] According to other embodiments of the electric vehicle, the deployable and / or expandable bag may have a shape such that its top side is arranged above the roof in the deployed and / or expanded state. For example, in the activated state (i.e., the expanded and / or deployed state), the bag may have a rectangular or cylindrical shape, with its top side higher than the roof. Preferably, the height of the bag in the activated state may be 2m or more. Alternatively, the bag may be shaped such that its top side is located at a height of at least 2m above the earth's surface. This may be achieved in conjunction with the position of the bag extending out of the opening of the vehicle body.

[0019] According to the invention, there is also provided the use of at least one deployable and / or expandable bag which is connected to a degassing device of an HV battery so as to collect gases discharged through the degassing device which leave or have left at least one battery module in the event of damage.

[0020] It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or on their own, without departing from the scope of the present invention.

[0021] In general, the present invention discloses the following technical solutions 1, 5 and 8, and the following 2-4 and 6-7 are preferred technical solutions:

[0022] 1. A HV battery (2), comprising:

[0023] at least one battery module (3), the at least one battery module having a degassing valve or a degassing opening;

[0024] a degassing device (4) which is coupled to the degassing valve or the degassing opening and is configured to dissipate gases (6) leaving the battery module (3) in the event of damage;

[0025] The degassing device (4) comprises at least one expandable and / or flexible bag (5), which is connected to the outlet of the degassing device (4).

[0026] 2. The HV battery (2) according to the aforementioned solution 1,

[0027] The degassing device (4) comprises a pipeline system.

[0028] 3. The HV battery (2) according to the above-mentioned solution 1 or 2,

[0029] Wherein the expandable and / or flexible bag (5) comprises a pressure relief valve (7) or a defined opening.

[0030] 4. The HV battery (2) according to the aforementioned solution 3,

[0031] The pressure relief valve (7) is arranged on the bag such that the pressure relief valve is arranged on the top side of the deployable and / or flexible bag (5) in its deployed and / or expanded state.

[0032] 5. An electric vehicle (1), comprising:

[0033] The HV battery (2) according to any one of the above solutions 1-4;

[0034] In the electric vehicle (1), a degassing device (4) is arranged with a deployable and / or flexible bag (5) coupled thereto, so that the bag protrudes from the body of the electric vehicle (1) in a deployed and / or expanded state.

[0035] 6. The electric vehicle (1) according to the aforementioned solution 5,

[0036] The deployable and / or flexible bag (5) is configured so that in the event of damage it protrudes from the vehicle body due to gas (6) leaving the degassing device, so that the pressure relief valve (7) is arranged on the top side of the deployable and / or flexible bag.

[0037] 7. The electric vehicle (1) according to the aforementioned solution 5,

[0038] The deployable and / or flexible bag (5) can have a shape such that its top side is arranged above the vehicle roof (8) in the deployed and / or expanded state.

[0039] 8. Use of at least one deployable and / or flexible bag (5) connected to a degassing device (4) of an HV battery (2) in order to collect gases (6) discharged through the degassing device (4) that have left at least one battery module (3) in the event of damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Additional advantages and configurations of the invention emerge from the description and the drawings.

[0041] Figure 1 An exemplary embodiment of an HV battery is shown in an installed state, with the pouch in an unactivated state.

[0042] Figure 2 Shows Figure 1 An exemplary embodiment of a HV battery wherein the pouch is in an activated state. DETAILED DESCRIPTION

[0043] Figure 1An exemplary embodiment of an HV battery 2 according to the invention is shown, wherein the HV battery 2 is installed in an electric vehicle 1. The HV battery 2 comprises two battery modules 3 and is arranged in the underbody of the electric vehicle 1. The degassing valves of the battery modules 3 are connected to outlets via a degassing device 4 comprising a pipeline, through which outlets hot gases can generally be selectively discharged from the battery cells and the battery module 3 in the event of thermal runaway of one of the battery cells in the battery module 3. In general, the degassing device 4 forms a common fluid-mechanical and outwardly sealed connection between the two outlets of the degassing device 4 and the two battery modules 3. In the HV battery 2 according to the invention, a deployable and / or flexible bag 5 is arranged at each of two shown (not explicitly shown in the figure) outlets of the degassing device 4, each outlet being arranged in the region of the wheel housing. Figure 1 In the embodiment, the two bags 5 are not activated, ie they are in a collapsed and unexpanded state.

[0044] exist Figure 2 In the Figure 1 , but during a thermal event. During thermal runaway of one or more battery cells, the bags 5 unfold and / or expand, thereby being in their activated state. In this state, they collect hot gases from at least one damaged battery cell, represented by arrows 6. Thus, the hot gases do not enter the environment in an uncontrolled manner. Figure 2 As shown, the two bags 5 may be deployed and / or expanded to different degrees and sizes.

[0045] A pressure relief valve 7 is provided on the top side of the activated right bag 5, which is arranged in the region of the door sill. When the limit pressure is reached in the bag 5, the pressure relief valve 7 opens, thereby allowing the internal pressure to be reduced in a controlled manner. The shape of the bag 5 is selected so that the pressure relief valve 7 is arranged above the roof 8 of the electric vehicle 1 when triggered. The pressure relief valve 7 can be provided to prevent the bag 5 from bursting in the activated state.

Claims

1. A HV battery (2), comprising: at least one battery module (3), the at least one battery module having a degassing valve or a degassing opening; a degassing device (4) which is coupled to the degassing valve or the degassing opening and is configured to dissipate gases (6) leaving the battery module (3) in the event of damage; The degassing device (4) comprises at least one expandable and / or flexible bag (5), which is connected to the outlet of the degassing device (4).

2. The HV battery (2) according to claim 1, The degassing device (4) comprises a pipeline system.

3. The HV battery (2) according to claim 1 or 2, Wherein the expandable and / or flexible bag (5) comprises a pressure relief valve (7) or a defined opening.

4. The HV battery (2) according to claim 3, The pressure relief valve (7) is arranged on the bag such that the pressure relief valve is arranged on the top side of the deployable and / or flexible bag (5) in its deployed and / or expanded state.

5. An electric vehicle (1), comprising: An HV battery (2) according to any one of the preceding claims; In the electric vehicle (1), a degassing device (4) is arranged with a deployable and / or flexible bag (5) coupled thereto, so that the bag protrudes from the body of the electric vehicle (1) in a deployed and / or expanded state.

6. The electric vehicle (1) according to claim 5, The deployable and / or flexible bag (5) is configured so that in the event of damage it protrudes from the vehicle body due to gas (6) leaving the degassing device, so that the pressure relief valve (7) is arranged on the top side of the deployable and / or flexible bag.

7. The electric vehicle (1) according to claim 5, The deployable and / or flexible bag (5) can have a shape such that its top side is arranged above the vehicle roof (8) in the deployed and / or expanded state.

8. Use of at least one deployable and / or flexible bag (5) connected to a degassing device (4) of an HV battery (2) in order to collect gases (6) discharged through the degassing device (4) that have left at least one battery module (3) in the event of damage.

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