Batteries for motorized vehicles and motorized vehicles

Abstract

To reliably exhaust high-temperature gas from a battery cell when the battery cell experiences thermal runaway. A battery (10) for a motor vehicle includes a battery housing (14) having a plurality of battery cells (12) and a perforated thin plate (20) surrounding an interior space (16) for receiving the battery cells (12) and on which the battery cells (12) are mounted. the perforated thin plate (20) has ventilation openings allocated to the battery cells (12), the battery cells (12) are placed on the ventilation openings, and gases emitted from the battery cells (12) can be discharged from the housing interior space (16) through the ventilation openings; A gap is provided between the battery cells 12 and the perforated thin plate, and the battery cells 12 are surrounded by foam material in the housing interior space 16; and / or A crash-absorbing foam material 48 is adhered to the side of the perforated sheet 20 opposite the battery cells 12 .

Description

[Technical Field]

[0001] The present invention relates to a battery for a motor vehicle and to a motor vehicle having a battery. [Background technology]

[0002] Patent Document 1 discloses an energy battery housing arrangement for a motor vehicle, which has an energy battery (storage unit) housing and an underrun protector fixed to the energy battery housing at its underside. The underrun protector has a sandwich arrangement with an upper cover plate on its upper side facing the energy battery housing and a lower cover plate on its lower side, with a filling medium arranged between the upper and lower cover plates, and the upper side of the sandwich arrangement is perforated for webs or ribs.

[0003] Patent Document 2 discloses a battery having a plurality of individual battery cells, the individual battery cells being connected to a cooling element at at least one end thereof via an elastic tolerance compensation element, and an electrical insulating film being disposed between the individual battery cells and the cooling element, where the insulating film and the tolerance compensation element are integrally formed or connected to each other by a material bonding (welding) method.

[0004] Furthermore, Patent Document 3 discloses a battery module arrangement comprising a plurality of battery cells, each of the plurality of battery cells having a cell opening formed therein and a plate arrangement defining a chamber, the chamber containing a fluid therein, and further comprising a plurality of openings extending through the plate arrangement, each of the plurality of openings being configured to face the cell opening of one of the battery cells.

[0005] Additionally, Patent Document 4 discloses a battery module, and Patent Document 5 discloses a battery housing for a vehicle battery. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] German Patent Application Publication No. 10201920646 [Patent Document 2] German Patent Application Publication No. 102011103993 [Patent Document 3] German Patent Application Publication No. 102019200465 [Patent Document 4] International Publication No. 2022 / 031056 [Patent Document 5] German Patent Invention No. 102017103654 Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the invention is to provide a solution which allows a particularly reliable evacuation of hot gases from the battery cells of a battery in the event of a thermal runaway of the battery cells. [Means for solving the problem]

[0008] The problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description and the drawings. Features, advantages and possible configurations indicated in the description of one of the subject matter of the independent claims may be considered as all possible combinations of the subject matter of the independent claims at least with the features, advantages and possible configurations of each of the subject matter of the other independent claims and, where appropriate, with one or more of the dependent claims.

[0009] The present invention relates to a battery for a motor vehicle configured to provide electrical drive energy for an electric powertrain of the motor vehicle. This means that the motor vehicle can be powered by electrical energy from the battery. The battery may be, in particular, a high-voltage battery for the motor vehicle. The battery includes a plurality of battery cells and a battery housing. The battery housing encloses an interior space for accommodating the plurality of battery cells. The battery housing also includes a perforated thin plate on which the battery cells are mounted. Mounting the battery cells on the perforated thin plate can be understood to mean that the weight of the battery cells is supported by the perforated thin plate. Thus, in the normal mounting position of the battery in the motor vehicle, the battery cells are arranged above the perforated thin plate in the vehicle height direction. The battery cells can be mounted directly on the perforated thin plate or indirectly via at least one other component. A cover of the battery housing forms a sandwich structure together with the perforated thin plate and the battery cells arranged therebetween. The sandwich structure makes it possible to achieve a particularly high overall stiffness of the battery.

[0010] The perforated plate has an assigned ventilation opening for each battery cell, and the assigned battery cell is installed in the ventilation opening. Gas from the assigned battery cell can be discharged from the housing interior space through the ventilation opening. Therefore, by installing each battery cell on the perforated plate and arranging it above the perforated plate in the vehicle height direction in the specified installation position, gas generated in the event of thermal runaway of a battery cell can be discharged downward from the battery. This downward discharge of the generated gas can particularly reduce the risk of the gas entering the passenger compartment of the motor vehicle. Furthermore, by discharging gas downward from each battery cell when the battery is arranged in the underside region of the motor vehicle, gas can be discharged from the motor vehicle over a particularly short path.

[0011] Thermal runaway and heat propagation of battery cells, i.e. the propagation of thermal events from battery cell to battery cell in a battery, is one of the major safety technical challenges during the operation of lithium-ion batteries, as they are used more and more in the growing segment of electromobility. Heat propagation can be particularly well avoided by providing perforated thin plates with ventilation openings that allow hot gases generated in the event of thermal runaway of the battery cells to escape from the battery cells.

[0012] Each battery cell can completely cover its assigned air vent opening upward in the vehicle height direction, thereby preventing gas from flowing back into the housing interior space via the air vent opening. Furthermore, this allows the exhaust openings arranged below the battery cells to be reliably arranged above the assigned air vent opening. This ensures that a particularly large portion, particularly all, of the gas generated during thermal runaway of the battery cells is reliably discharged from the battery cells via the air vent opening, thereby particularly reliably preventing the gas from entering the housing interior space. Each air vent opening can in particular be aligned in a straight line (in line) with the exhaust opening of the respective assigned battery cell.

[0013] In the present invention, gaps are formed between the battery cells and the perforated thin plate, and the battery cells are surrounded by a foam material in the housing interior space, with the foam material configured to close the gaps and the ventilation openings. The volume of the housing interior space not filled with the battery cells or electronic devices can be filled with the foam material, thereby reliably holding all battery components in their respective positions within the housing interior space. The foam material also penetrates into the gaps between each battery cell and its assigned ventilation opening and closes the ventilation openings in the perforated thin plate. The foam material hardens at the ventilation openings in the perforated thin plate, thereby providing a sealing layer. The foam material is configured to melt upon contact with hot gases emitted from each battery cell, thereby opening the ventilation openings closed with the foam material to vent the gas from the housing interior space. Thus, the foam material can be used to fix all battery components in the housing interior space and to seal the ventilation openings in a particularly watertight manner.

[0014] Alternatively or additionally, the crash-absorbing foam is glued to the side of the perforated plate opposite the battery cells. The glueing of the crash-absorbing foam to the perforated plate ensures that the crash-absorbing foam is held particularly securely to the perforated plate. In particular, in battery configurations that have both the crash-absorbing foam glued to the perforated plate and the tray, the tray can be particularly easily replaced because the crash-absorbing foam is securely held to the perforated plate.

[0015] In one possible development of the invention, the perforated sheet is configured to be made of steel or aluminum. A perforated sheet made of aluminum has a particularly low weight. A perforated sheet made of steel has particularly high strength and rigidity and therefore a particularly long service life. Likewise, the perforated sheet can be made of both steel and aluminum.

[0016] In another possible configuration of the present invention, the air release openings are configured to be sealed, particularly watertight, using a sealing layer. The sealing layer is configured to be overcome by hot gases escaping from the battery cells in the event of thermal runaway. Thermal runaway is understood to mean the ignition or explosion of a battery cell due to an exothermic reaction in each battery cell. To avoid a chain reaction from several battery cells to all battery cells of the battery and thus prevent the establishment of a self-sustaining reaction, the gases generated in the event of thermal runaway of an individual battery cell are discharged through the corresponding air release opening. The sealing layer is provided to ensure the tightness of the housing interior space during normal operation of the battery, particularly the water tightness to prevent water from entering the housing interior space. Thus, the sealing layer itself, together with the perforated sheet, provides the respective predetermined breakage points by means of which the air release openings are closed during normal operation and which are opened by hot gases via the predetermined breakage points in the event of thermal runaway. The opening is achieved by at least locally melting the sealing layer with the hot gas, which allows the gas to escape from the housing interior space through the opened ventilation opening. The sealing layer therefore provides particularly good protection for the battery cells against water penetration and also ensures that hot gas can be reliably released through the ventilation openings in the perforated plate in the event of thermal runaway of at least one of the battery cells.

[0017] In another possible configuration of the present invention, the sealing layer includes an adhesive layer through which the battery cells are bonded to the perforated plate and / or the sealing layer includes at least one synthetic resin element in contact with the perforated plate. In other words, the perforated plate can be coated with an adhesive that closes the ventilation openings in the perforated plate and bonds the battery cells to the perforated plate. The adhesive thus enables a sealing, particularly a watertight sealing, of the housing interior space, and a secure fixation of the battery cells in the housing interior space. The battery cells can be securely held in the perforated plate via the adhesive, thereby preventing relative movement of the battery cells relative to one another or the battery housing, thereby minimizing the risk of damage to the battery cells. The synthetic resin elements can be, for example, synthetic resin plugs that extend into the ventilation openings in the perforated plate to close the ventilation openings. Alternatively, the synthetic resin element may be a synthetic resin plate attached to the perforated sheet on the side facing the housing interior or on the side opposite the housing interior, so that at least one, particularly several, and particularly all, of the ventilation openings of the perforated sheet are covered and therefore sealed with the synthetic resin plate. If only one synthetic resin element is provided, the synthetic resin element seals all of the ventilation openings of the perforated sheet. If several synthetic resin elements are provided to provide sealing layers, each of the synthetic resin elements seals at least one, particularly several, of the ventilation openings of the perforated sheet. In the event of thermal runaway of the assigned battery cell, the adhesive layer or synthetic resin element at least partially melts upon contact with the hot gas generated, thereby opening the assigned ventilation opening of the perforated sheet. Hot gas can then escape through the opened ventilation opening.

[0018] In another possible configuration of the present invention, a tray is arranged on the side of the perforated sheet opposite the battery cells, and the tray, together with the perforated sheet, is configured to enclose a buffer volume in which a crash-absorbing foam is arranged. The tray, particularly together with the crash-absorbing foam, can provide an underrun protector for a battery or motor vehicle. The crash-absorbing foam can be configured to be vehicle-specific and can be used for different high-voltage batteries. Alternatively or additionally, the crash-absorbing foam can be configured to be battery-specific and can be used for different vehicles. The crash-absorbing foam is configured to protect the perforated sheet from mechanical damage, such as scratches and resulting corrosion. The tray can be made of metal or fiber-reinforced synthetic resin. For example, the tray has a sandwich structure consisting of two overlapping components, each made of fiber-reinforced synthetic resin and a spacer, particularly filled foam, between the two components. The crash-absorbing foam is configured to deform during a collision, thereby converting kinetic energy into deformation energy. This allows the battery cells of the battery to be particularly well protected from damage. The tray, in turn, is configured to hold the crash-absorbing foam. Furthermore, the tray is configured to prevent impacts from below on the mounting position of the battery in the motor vehicle. The tray and the crash-absorbing foam therefore provide particularly good protection for the battery cells from damage, thereby enabling a particularly long service life for the battery cells. Furthermore, the ventilation openings in the perforated thin plate allow hot gas generated in the event of thermal runaway of the battery cells to be vented to a buffer volume. In this buffer volume, gas generated in the event of thermal runaway of at least one battery cell can be collected and discharged from the battery cells. Pipes can be provided in the crash-absorbing foam to discharge hot gas from the battery cells.

[0019] In this connection, it is possible, in particular, to configure the tray so that it is tightly connected to the perforated plate, which means that the buffer volume is tightly enclosed by the perforated plate and the tray, especially if a sealing layer is present, and thus it is possible to avoid any undesirable escape of hot gas from the buffer volume.

[0020] In another possible configuration of the invention, the tray is configured to be held reversibly in the battery housing. In particular, the tray can be replaced non-destructively. Therefore, in particular in the event of tray damage, it is particularly easy to remove the damaged tray from the battery housing and place and fix a new tray in the battery housing. Therefore, in the event of damage to only the tray, it is possible to avoid a complete replacement of the entire battery. The battery is therefore particularly sustainable and easily repairable.

[0021] Furthermore, the invention relates to a motor vehicle comprising a battery as described above in relation to the battery according to the invention.

[0022] Further features of the invention will become apparent from the claims, the drawings and the description thereof. The features and combinations of features described herein above and those merely shown in the description and / or drawings below can be used not only in the respective combinations described, but also in other combinations or alone, without departing from the scope of the invention. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view of a portion of a battery for a motor vehicle. [Figure 2] FIG. [Figure 3] FIG. 2 is a schematic perspective view of a porous thin plate of the battery. DETAILED DESCRIPTION OF THE INVENTION

[0024] In the various figures, identical and functionally identical elements are designated by the same reference numerals.

[0025] FIG. 1 shows a partially cutaway view of a battery 10 for a motor vehicle. The battery 10 includes a plurality of battery cells 12 configured to provide electrical energy to an electrical powertrain of the motor vehicle. The battery 10 is, in particular, a traction battery for a motor vehicle. In addition to the plurality of battery cells 12, the battery 10 includes a battery housing 14. The battery housing 14 encloses a housing interior space 16 that accommodates the plurality of battery cells 12. The battery housing 14 here includes a cover 18 and a perforated sheet metal 20 that provides the bottom of the battery housing 14. The cover 18 defines the housing interior space 16 upward in the vehicle height direction z when the battery 10 is installed in the motor vehicle as intended, and the perforated sheet metal 20 defines the housing interior space 16 downward in the vehicle height direction z.

[0026] As can be seen in FIG. 1 , the battery cells 12 are arranged above the perforated plate 20 in the vehicle height direction z. In particular, the battery cells 12 are supported by the perforated plate 20. For this purpose, the battery cells 12 can be placed directly or indirectly on the perforated plate 20. The bottom of the battery housing 14 is formed by a high-voltage battery (storage battery, storage) tray 22, here provided with the perforated plate 20. The high-voltage battery tray 22 is made of steel and serves as a thrust field. Both the high-voltage battery tray 22 and the cover 18 are connected via first bolt connections 24 to a rocker panel 26 of the motor vehicle at the mounting location of the battery 10 in the motor vehicle. The high-voltage battery tray 22 with the perforated plate 20 is shown separately in FIG. 3 . As can be particularly clearly seen in FIG. 3 , the perforated plate 20 has a number of vent openings 28. 3, for reasons of clarity, only one of the ventilation openings 28 is shown with the corresponding reference numeral. The perforated thin plate 20 is provided with a corresponding ventilation opening 28 for each battery cell 12.

[0027] FIG. 2 shows a portion of the battery 10, and in this portion, it can be particularly clearly seen that each battery cell 12 is arranged above a corresponding air vent opening 28 in the vehicle height direction z. Here, the battery cell 12 completely covers the assigned air vent opening 28 in the vehicle height direction z. The air vent opening 28 is particularly arranged to cover the exhaust opening of the battery cell 12 downward in the vehicle height direction z. Here, the exhaust opening of the battery cell 12 is arranged below the battery cell 12. Therefore, gas, particularly hot gas, that flows out of the corresponding battery cell 12 through the exhaust opening, particularly due to thermal runaway of the battery cell 12, can be discharged from the battery cell 12 through the corresponding air vent opening 28. Therefore, hot gas generated in the battery cell 12 during thermal runaway can be discharged to the housing interior space 16 through the air vent opening 28.

[0028] To ensure that the housing interior space 16 is watertightly sealed during normal operation of the battery 10, i.e., when there is no thermal runaway of the battery cells 12, a sealing layer 30 is provided. The sealing layer 30 is disposed between the battery cells 12 and the perforated thin plate 20 and is configured to watertightly seal the entire air release opening 28. The sealing layer 30 can be formed of an adhesive, a synthetic resin material, or a foam material. The sealing layer 30 is configured to open the air release opening 28 assigned to the battery cell 12 in the event of thermal runaway of the battery cell 12. This can be achieved by locally melting the sealing layer 30, thereby opening a path from the battery cell 12 to the air release opening 28. Thus, in addition to ensuring the watertightness of the housing interior space 16 during normal operation of the battery 10, it can also be ensured that, in the event of thermal runaway of one of the battery cells 12, hot gas generated can be evacuated from the housing interior space 16 through the corresponding air release opening 28.

[0029] As can be seen in Figures 1 and 2, a tray 32 used as a bollard protection can be arranged below the battery housing 14 in the vehicle height direction z. The tray 32 can be a replaceable floor plate for the battery 10. Here, the replaceable floor plate has a sandwich structure made of a first glass-fiber reinforced synthetic resin member 34, a foam material 36, and a second glass-fiber reinforced synthetic resin member 38. Here, the tray 32 is fixed to the high-voltage battery tray 22 via at least one second bolt connection 42 and to the rocker panel 36 via at least one third bolt connection 44. The at least one second bolt connection 42 and the at least one third bolt connection 44 enable non-destructive, reversible exchange of the tray 32 in the battery housing 14 of the battery 10 and in the rocker panel 26 of the motor vehicle. 1 and 2, the tray 32 defines a buffer volume 46 together with the perforated thin plate 20. A crash-absorbing foam material 48 can be arranged in the buffer volume 46. The crash-absorbing foam material 48 can be glued to the underside of the perforated thin plate 20 opposite the battery cells 12. This ensures that the crash-absorbing foam material 48 is particularly securely fixed in the buffer volume 46. The crash-absorbing foam material 48 is a support structure for the battery 10 and also serves as a sacrificial member in the event of an impact from below.

[0030] The above-described battery 10 can improve the overall stiffness of a motor vehicle while improving repairability in the event of minor damage. Additionally, the battery 10 can provide a weight reduction over conventional batteries for each motor vehicle.

[0031] In the above-described battery 10, a perforated thin plate 20 is provided below the battery cells 12 in the vehicle height direction z, and a removable protective member, here a tray 32, and an integrated foam material, here a crash-absorbing foam material 48, are provided below the perforated thin plate 20. The housing bottom is provided with the perforated thin plate 20 so that generated gas is discharged to the crash-absorbing foam material 48, thereby preventing heat transfer from the battery cells 12. Thus, the battery cells 12 are vented to a buffer volume 46 surrounded by the removable tray 32.

[0032] The battery cells 12 can be glued to the perforated thin plate 20 from above. In this case, the ventilation openings 28 are watertightly closed with adhesive. Alternatively or additionally, the ventilation openings 28 are sealed with a synthetic resin material. The perforated thin plate 20 can be made of aluminum or steel and has a ventilation opening 28 below each battery cell 12. The ventilation opening 28 is closed to allow ventilation of the assigned battery cell 12. This means that hot gas in the battery cell 12 can break through the closure. A crash-absorbing foam 48 is arranged below the perforated thin plate 20, allowing ventilation of the battery cell 12. The crash-absorbing foam 48 is used to cushion the battery 10 from below. The crash-absorbing foam 48 is pre-attached to a tray 32 that can be removed from the motor vehicle and is glued to the perforated thin plate 20 from below. The tray 32 can be made of synthetic resin, especially glass fiber reinforced synthetic resin, and / or light metal.

[0033] If the sealing layer 30 is not provided, the housing interior space 16 can be sealed downwards with a tray 32 to prevent water from entering the housing interior space 16 .

[0034] The sandwich construction of the housing top or cover 18, battery cells 12, and perforated sheet metal 20 allows for particularly high overall rigidity of the battery 10. This provides functional separation between the battery housing 14 and the tray 32, which in combination with the crash-absorbing foam 48 provides underrun protection. The tray 32, together with the crash-absorbing foam 48, performs the functions of propagation protection and underrun protection.

[0035] Overall, the present invention shows how a sandwich high voltage battery (accumulator, storage) bottom with a vent penetration, here a vent opening 28, can be provided for the case of cell propagation. [Explanation of symbols]

[0036] 10 Battery 12 battery cells 14 Battery housing 16 Housing internal space 18 Cover 20 Perforated thin plate 22 Bottom of housing 24 First bolted joint 26 Rocker Panel 28 Vent opening 30 Sealing layer 32 trays 34 First glass fiber reinforced synthetic resin 36 Foam material 38 Second Glass Fiber Reinforced Synthetic Resin 42 Second bolted joint 44 Third bolt joint 46 Buffer volume 48 Impact absorbing foam z Vehicle height direction x longitudinal direction of vehicle y Lateral direction of the vehicle

Claims

1. - Multiple battery cells (12), - A battery housing (14) surrounds the internal space (16) of the housing, houses the battery cell (12), and is equipped with a porous thin plate (20) on which the battery cell (12) is installed. A battery (10) for a motor vehicle having, The porous thin plate (20) is provided with an assigned venting opening (28) for each battery cell (12), and the assigned battery cell (12) is installed on the venting opening, and the gas emitted from each assigned battery cell (12) can be discharged from the internal space (16) of the housing through the venting opening. - A gap is provided between the battery cell (12) and the porous thin plate (28), the battery cell (12) is surrounded by foam material in the internal space (16) of the housing, the foam material closes the gap and the ventilation opening (28), and / or - The impact-absorbing foam material (48) is bonded to the side of the porous thin plate (20) opposite to the battery cell (12). A battery (10) characterized by the following features.

2. The battery (10) according to claim 1, characterized in that the battery cells are directly mounted on the porous thin plate (20).

3. The battery (10) according to claim 1 or 2, characterized in that the venting opening (28) is sealed by a sealing layer (30), and the sealing layer is configured to be broken by high-temperature gas flowing out from the battery cell (12) during thermal runaway.

4. The battery (10) according to claim 3, characterized in that the sealing layer (30) comprises an adhesive layer, the battery cell (12) is bonded to the porous thin plate (20) via the adhesive layer, and / or the sealing layer (30) comprises at least one synthetic resin element that contacts the porous thin plate (28).

5. The battery (10) according to claim 1 or 2, characterized in that a tray (32) is arranged on the side of the porous thin plate (20) opposite to the battery cell (12), and the tray, together with the porous thin plate (20), surrounds a buffer volume (46) in which a collision-absorbing foam material (48) is arranged.

6. The battery (10) according to claim 5, characterized in that the tray (32) is tightly bonded to the porous thin plate (20).

7. The battery (10) according to claim 5, characterized in that the tray (32) is held reversibly in the battery housing (14).

8. A motorized vehicle having the battery (10) according to claim 1 or 2.

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