Method for dismantling a traction battery and corresponding device for dismantling a traction battery

Abstract

The invention relates to a method for dismantling a traction battery (1) for a motor vehicle, wherein the traction battery (1) comprises a battery housing (7) and a battery module (2) inserted into a battery module receptacle (6) of the battery housing (7), and the battery module (2) is connected via a thermal interface medium (12) to a cooling plate (8) that at least partially delimits the battery module receptacle (6). It is provided that, to remove the battery module (2) from the cooling plate (8), a suction cup (13) is applied to the cooling plate (8) on a side facing away from the battery module receptacle (6), and the cooling plate (8) is deflected towards the suction cup (13) by applying a vacuum to the suction cup (13). The invention further relates to a method for dismantling a traction battery (1) for a motor vehicle.

Description

[0001] The invention relates to a method for dismantling a traction battery for a motor vehicle, wherein the traction battery comprises a battery housing and a battery module inserted into a battery module receptacle of the battery housing, and the battery module is connected via a thermal conductor to a cooling plate that at least partially delimits the battery module receptacle. The invention further relates to a device for dismantling a traction battery for a motor vehicle.

[0002] For example, prior art is disclosed in US patent 2023 / 0321845 A1. This patent discloses a device for opening a housing, comprising: a suction section with a first suction section configured to draw in an upper section of a battery cell housing in a folded state, and a second suction section configured to draw in a lower section of the housing; and a rotary drive section configured to open the interior of the housing by rotating the first suction section. The first suction section and the second suction section can be configured to move in a first direction and draw in the upper section and the lower section of the housing, respectively.

[0003] Tools for dismantling or disassembling a battery cell are known from publications CN 217475260 U1 and CN 117443896 A.

[0004] The object of the invention is to propose a method for dismantling a traction battery for a motor vehicle which has advantages over known methods, in particular ensuring reliable separation of the battery module from the cooling plate.

[0005] According to the invention, this is achieved by a method for dismantling a traction battery for a motor vehicle with the features of claim 1. It is provided that, to remove the battery module from the cooling plate, a suction cup is applied to the cooling plate on a side facing away from the battery module receptacle, and the cooling plate is deflected towards the suction cup by applying a vacuum to the suction cup.

[0006] Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims. It should be noted that the exemplary embodiments described in the description are not limiting; rather, any variations of the features disclosed in the description, the claims, and the figures are possible.

[0007] The method according to the invention serves to dismantle, i.e., to disassemble, the traction battery. The traction battery is preferably a component of the motor vehicle; however, it can, of course, also exist separately, particularly until the traction battery is mounted on or in the motor vehicle or after its removal from the motor vehicle. The traction battery is designed and configured for the intermediate storage of electrical energy for a drive system of the motor vehicle. The drive system serves to propel the motor vehicle, i.e., to provide a drive torque directed towards propelling the motor vehicle. To provide the drive torque, the drive system has at least one drive unit, which is designed as an electric traction motor and is electrically connected to the traction battery.

[0008] The traction battery comprises a battery cell arrangement, which in turn includes at least one battery cell, and in particular exactly one battery cell or several battery cells. The battery cell is preferably a prismatic cell or a pouch cell. Wherever this description refers to the battery cell or the at least one battery cell, the explanations are always equivalent. Explanations relating to the at least one battery cell are applicable to the battery cell and vice versa. If the battery cell arrangement comprises several battery cells, the explanations relating to the battery cell or the at least one battery cell are applicable to the several battery cells, and in particular to each of the several battery cells.

[0009] The battery cell assembly forms part of the battery module. The battery module preferably includes end plates and / or a clamping device in addition to the battery cell assembly. The end plates are, for example, part of a battery module housing and accommodate the battery cell assembly between them. The battery cell assembly is positioned between the end plates and clamped by means of the clamping device to form the battery module. In this respect, the end plates are arranged on opposite sides of the battery cell assembly. Preferably, the battery module is cuboid or at least approximately cuboid. In the simplest case, it has at least one battery cell, but preferably several battery cells. Optionally, the battery module includes the end plates and / or the clamping device.

[0010] If the battery cell arrangement comprises multiple battery cells, these are preferably electrically interconnected. For this purpose, the battery cells are arranged, for example, such that their electrical connections are on the same side and / or facing each other. The connections are electrically linked to one or more busbars, which are preferably also electrically connected to the electrical connections of the battery module and / or the traction battery. In other words, the battery cells of the battery module are electrically connected to the terminals via the busbars.

[0011] The traction battery has a battery housing containing a battery module receptacle, designed and configured to hold one or more battery modules. During the manufacturing process, the battery module is inserted into the receptacle. Preferably, not just a single battery module is arranged in the battery housing, but rather several battery modules are inserted into the battery housing. In such a configuration, the battery housing has a corresponding battery module receptacle designed and configured to hold multiple battery modules.

[0012] During operation of the traction battery, heat is generated in the battery cell assembly, which must be dissipated, or heat must be supplied to reach a specific temperature of the battery cell assembly. For this reason, the battery module is connected to the cooling plate via heat transfer. The cooling plate defines the battery module recess in at least one direction and thus serves as the housing wall of the battery housing. Preferably, at least one coolant channel is provided in the cooling plate, through which a fluid, particularly a coolant, flows at least intermittently. The cooling plate thus forms part of a temperature control device by means of which the battery module is at least intermittently temperature-controlled. With the aid of the temperature control device, heat is at least intermittently dissipated from the battery module and / or heat is supplied to the battery module at least intermittently.

[0013] The cooling plate, to which the battery module is thermally connected, defines the battery module's mounting area. For example, the cooling plate is a base plate or bottom wall of the battery housing, thus limiting the battery module's mounting area when the traction battery is installed in its intended position facing downwards. During the manufacturing process, the battery module is inserted into the battery housing in such a way that it, or rather its battery cell arrangement, is subsequently connected to the cooling plate via heat transfer. A thermal interface material is used to ensure a reliable connection between the battery module or battery cell arrangement and the cooling plate.

[0014] The thermal interface material is, for example, a thermal paste, specifically a viscous, thermally conductive material. Thermal paste can also be referred to as a "gap filler." Alternatively, a thermally conductive adhesive can be used as the thermal interface material. Compared to thermally conductive adhesive, thermal paste has inferior mechanical properties but superior thermal properties. When thermal interface material is used, it is usually relatively easy to remove the battery module from the battery housing, for example, during the manufacturing of the traction battery or for servicing. Thermally conductive adhesive, on the other hand, has superior mechanical properties compared to thermal interface material but inferior thermal properties. It enables a mechanically advantageous connection between the cooling plate and the battery module.

[0015] Particularly when using thermally conductive adhesive, which creates a material-bonded connection between the battery module and the cooling plate, it is essential to ensure that the battery module can be reliably removed from the cooling plate during disassembly of the traction battery. For this purpose, the invention proposes the use of a suction cup. The suction cup is applied to the cooling plate, specifically on the side facing away from the battery module mounting, to remove the battery module from the cooling plate, or vice versa. The suction cup is then subjected to a vacuum, so that the vacuum acts on the cooling plate in the area covered by the suction cup.

[0016] This ultimately means that a pressure difference is created above the cooling plate using the suction cup. On the side of the battery module mount, ambient pressure acts on the cooling plate, while on the side of the cooling plate opposite the battery module mount, a vacuum exists. A vacuum is defined as a pressure lower than the pressure acting on the cooling plate on the side of the battery module mount, in particular the ambient pressure.

[0017] The suction cup has a cavity into which the cooling plate is deflected by the negative pressure. Under the influence of the negative pressure, the cooling plate deforms in such a way that it moves away from the battery module and enters the cavity of the suction cup. In this way, the cooling plate can be lifted from the battery module without damage, allowing the module to be easily removed from the battery housing. Using the suction cup also eliminates the need to attach the battery module to the cooling plate with thermally conductive adhesive.

[0018] The suction bell is made of, for example, plastic and / or metal. The cavity within the suction bell is designed such that it opens towards the cooling plate. The suction bell is positioned on the cooling plate to create a substantially airtight connection. The negative pressure is generated by at least partially evacuating the cavity. For example, a vacuum pump is fluidically connected to the suction bell and used to evacuate the cavity. The suction bell, and in particular its cavity, is dimensioned, for example, such that it only covers the battery module and not adjacent battery modules. Preferably, however, the suction bell or its cavity covers several battery modules arranged side by side, so that multiple battery modules can be detached from the cooling plate simultaneously using the suction bell.

[0019] A further development of the invention provides that the suction bell has a suction bell base on its side facing away from the cooling plate, from which at least one end stop projects towards the cooling plate, wherein the vacuum is applied such that the cooling plate rests against the end stop. The cavity of the suction bell is bounded by the suction bell base, namely in the direction facing away from the cooling plate. The at least one end stop extends from the suction bell base and projects towards the cooling plate. For example, the end stop penetrates at least 40%, at least 50%, or at least 60% of the cavity in the direction of the cooling plate.

[0020] There can be only a single end stop; however, preferably several end stops extend from the suction bell base. Whenever this description refers to the end stop or at least one end stop, the explanations are always equivalent. Explanations regarding the end stop are applicable to at least one end stop, and conversely, explanations regarding at least one end stop are applicable to the end stop. Furthermore, the explanations for the end stop are preferably applicable to each of the multiple end stops, if any are present.

[0021] The end stop serves to limit the deflection of the cooling plate due to the negative pressure in the direction away from the battery module holder. This limitation reliably prevents plastic deformation of the cooling plate. The end stops are designed and extended accordingly to achieve this goal. This approach ensures both the reliable release of the battery module from the cooling plate and simultaneously prevents impermissible deformation of the cooling plate.

[0022] A further development of the invention provides that, in addition to deflecting the cooling plate, the battery module is subjected to a removal force so that it is moved away from the cooling plate. Of course, it is possible to hold the battery module in a fixed position and only deflect the cooling plate using the suction cup. In this case, the battery module is preferably removed from the battery module holder after the cooling plate has been deflected. However, it is more preferred to apply the removal force to the battery module simultaneously with the application of the vacuum. The removal force is directed towards removing the battery module from the cooling plate, i.e., it acts in the direction away from the cooling plate. The removal force is selected such that the battery module is moved out of the battery module holder, i.e., in the direction away from the cooling plate.This procedure allows for rapid removal of the traction battery.

[0023] A further development of the invention provides that an edge of the suction bell is provided with a seal that forms a fluid-tight seal against the cooling plate. The suction bell comprises a base body and a seal, the seal being arranged on and extending from the base body. In particular, the seal completely and continuously surrounds the opening of the suction bell. The seal preferably consists of a material that has a higher elasticity than the material of the base body. Preferably, the base body is made of plastic or metal. The seal consists, for example, of an elastomer. The suction bell is arranged on the traction battery such that the seal is in continuous, tight contact with the cooling plate. The seal is preferably designed to compensate for any unevenness in the cooling plate.With such a design of the suction bell or such a procedure, efficient deflection of the cooling plate is achieved by applying the negative pressure.

[0024] A further development of the invention provides that a cooling plate with at least one coolant channel is used as the cooling plate. The cooling plate is therefore designed and configured to cool the battery module using a coolant, in particular a liquid coolant. For this purpose, the at least one coolant channel is fluidically connected to a coolant circuit of the traction battery and / or the vehicle. The coolant is circulated at least intermittently in the coolant circuit, so that it flows through the at least one coolant channel of the cooling plate. While in the coolant channel, the coolant absorbs heat from the battery module, so that the heat is carried away from the coolant channel along with the coolant.

[0025] The design of the coolant channel in the cooling plate enables highly efficient cooling, but results in low stiffness of the cooling plate. In particular, the stiffness of the cooling plate is lower than that of the battery module. Consequently, if the battery module is not adequately secured to the cooling plate, the cooling plate can deform, causing a gap between the cooling plate and the battery module. This leads to reduced cooling performance, as heat can no longer be transferred directly from the battery module to the cooling plate or to the coolant in the cooling channel. For this reason, it is particularly advantageous to thermally connect the cooling plate to the battery module reliably, namely using a thermal interface material. This ensures reliable cooling of the battery module by the cooling plate in all cases.

[0026] A further development of the invention provides that a cooling plate with at least one degassing opening closed by means of a closure is used as the cooling plate. The battery module has a rupture valve which opens when a certain burst pressure in the battery module is exceeded, creating a flow connection between the interior of the battery module and its external environment. Opening the rupture valve achieves pressure equalization between the interior and the external environment and prevents uncontrolled rupture of the battery module, for example in the event of thermal runaway of one or more of the battery cells. When the rupture valve opens, gases from the interior of the battery module enter the battery module receptacle of the battery housing.

[0027] To allow these gases to escape from the battery module housing, the cooling plate features a degassing vent, which is sealed with a cap. This cap may also function as a rupture valve, opening when a certain internal pressure of the battery housing is exceeded, thus creating a gas flow path between the battery module housing and the external environment of the traction battery. This allows the gases that have entered the battery module housing to escape to the external environment. For example, the degassing vent may be located in conjunction with the rupture valve of the battery module or the rupture valve of one of the battery cells. The degassing vent also results in a relatively low rigidity of the cooling plate, making a reliable thermal connection between the battery module and the cooling plate essential. This connection is achieved using a thermal interface material.

[0028] A further development of the invention provides that the suction bell is positioned against the cooling plate in such a way that it overlaps the degassing opening. Preferably, the suction bell is arranged so that it completely covers the degassing opening, meaning that the degassing opening is completely enclosed by the opening of the suction bell. Preferably, the suction bell is arranged symmetrically with respect to the degassing opening, with the degassing opening located approximately centrally within the opening of the suction bell. In other words, a longitudinal axis of the suction bell intersects the degassing opening, preferably at its center. Such an arrangement of the suction bell allows for targeted utilization of the comparatively low stiffness of the cooling plate in the area of ​​the degassing opening. This simplifies the deflection of the cooling plate into the cavity of the suction bell by means of the negative pressure.

[0029] A further development of the invention provides that a thermally conductive adhesive is used as the thermal conductor, bonding the battery module to the cooling plate over its entire surface, particularly only in the area surrounding the degassing vent. The thermally conductive adhesive is understood to be an adhesive that is thermally conductive, for example, through the use of one or more additives. The thermally conductive adhesive bonds the battery module and the cooling plate over its entire surface, not just at specific points. The bonded connection of the cooling plate to the battery module results in high rigidity of the cooling plate, even if it has at least one coolant channel and / or the degassing vent. If the degassing vent is present, the battery module is preferably bonded to the battery module using the thermally conductive adhesive only in the area surrounding this vent.

[0030] The use of thermally conductive adhesive ensures that the cooling plate is always reliably attached to the battery module. In particular, it prevents unwanted deformation of the cooling plate, which could lead to a separation between the cooling plate and the battery module, thus reducing the battery module's cooling performance. Accordingly, the battery module is reliably thermally connected to the cooling plate. Furthermore, the thermally conductive adhesive also ensures that the cooling plate remains reliably attached to the battery module in the event of thermal runaway. This guarantees a seal between the high-voltage area and the degassing area.

[0031] A further development of the invention provides that a multi-component adhesive containing a thermally conductive filler is used as the thermally conductive adhesive. The multi-component adhesive is, for example, an epoxy resin adhesive. This exhibits high strength. The multi-component adhesive is provided with the thermally conductive filler. For example, a ceramic and / or metallic material is used as the filler. In any case, the thermally conductive adhesive formulated in this way achieves both a reliable mechanical bond and good thermal bonding of the battery module to the cooling plate.

[0032] The invention further relates to a device for dismantling a traction battery for a motor vehicle, in particular for carrying out the method as described in this description, wherein the traction battery comprises a battery housing and a battery module inserted into a battery module receptacle of the battery housing, and the battery module is connected via a thermal conductor to a cooling plate that at least partially delimits the battery module receptacle. The device is provided to have a suction cup and is designed and configured to apply the suction cup to the cooling plate on a side facing away from the battery module receptacle in order to remove the battery module from the cooling plate, and to deflect the cooling plate towards the suction cup by applying a vacuum to the suction cup.

[0033] The advantages of such a device design and procedure have already been mentioned. Both the device for dismantling the traction battery and the method for operating it may be further developed as explained in this description, and reference is made to these explanations in this regard.

[0034] The features and combinations of features described in the description, in particular those described in the following figure description and / or shown in the figures, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention, in particular the scope of the claims. Thus, embodiments that are not explicitly shown or explained in the description and / or the figures, but which emerge from or can be derived from the explained embodiments, particularly within the scope of the claims, are also to be considered as encompassed by the invention.

[0035] The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without limiting the invention. The drawing shows: Fig. 1 a schematic representation of a traction battery for a motor vehicle and of a device for dismantling the traction battery during a first process step, as well as Fig. 2 A schematic representation of the traction battery and the device during a second process step.

[0036] The Fig. Figure 1 shows a schematic representation of a traction battery 1 for a motor vehicle, of which a battery module 2 with a battery cell 3 is shown in particular. The battery module 2, or the battery cell 3, has electrical connections 4 and 5, which can also be referred to as terminals. The battery module 2 is arranged in a battery module holder 6 of a battery housing 7, of which only a cooling plate 8 is shown here. The cooling plate 8 has at least one coolant channel 9 through which coolant is conveyed, at least temporarily, to regulate the temperature or cool the battery module 2.

[0037] The cooling plate 8 has a degassing opening 10 through which gases produced during thermal runaway of the battery module 2 or battery cell 3 can escape from the battery housing 7. The degassing opening 10 is closed by means of a closure 11. The closure 11 is, for example, in the form of a rupture valve or the like. The cooling plate 8 is thermally connected to the battery module 2 by means of a thermal conductor 12. In the illustrated embodiment, the thermal conductor 12 is a thermally conductive adhesive, which bonds the battery module 2 and the cooling plate 8 together.

[0038] To disconnect the connection between the cooling plate 8 and the battery module 2, particularly the bonded connection, during the disassembly of the traction battery 1, a suction cup 13 is used. This suction cup has a base body 14 and a seal 15 arranged on the base body 14. The suction cup 13 has a cavity 16 that opens towards the battery housing 7 and accordingly has an outlet 17. The outlet 17 is preferably completely and continuously enclosed by the seal 15.

[0039] In the direction away from the battery housing 7, the cavity 16 is bounded by a suction cup base 18 of the suction cup 13 or the base body 14. At least one end stop 19 extends from the suction cup base 18 towards the battery housing 7. In the illustrated embodiment, there are two end stops 19, which are arranged on opposite sides of the degassing opening 10. The illustration shows how, in a first process step during the disassembly of the traction battery 1, the suction cup 13 is applied to the battery housing 7, more precisely to the cooling plate 8. The suction cup 13 forms part of a device for disassembling the traction battery 1.

[0040] The Fig.Figure 2 shows a schematic representation of the traction battery 1 and the device 20 during a second process step. During the second process step, the suction bell 13 is subjected to a vacuum, so that the pressure in the cavity 16 is lower than on the side of the cooling plate 8 facing away from the cavity 16. Due to this pressure difference, the cooling plate 8 is deflected away from the battery module 2, preferably deforming only elastically, but not plastically.

[0041] It is evident that the cooling plate 8 rests against the end stops 19 due to its deflection caused by the negative pressure. The end stops 19 are dimensioned such that plastic deformation of the cooling plate 8 is prevented. The deflection of the cooling plate 8 at least partially releases the material bond between the cooling plate 8 and the battery module 2. Subsequently, the battery module 2 can be easily removed from the battery housing 7. The device 20 thus enables extremely simple disassembly of the traction battery 1. REFERENCE MARK LIST: 1 traction battery 2 battery modules 3 battery cells 4 connection 5 connection 6 Battery module mount 7 Battery housings 8 cooling plates 9 Coolant channel 10 Degassing opening 11 Closure 12 Thermal conductors 13. Suction cup 14 basic shapes 15 Seal 16 Cavity 17 Mouth opening 18 suction cup base 19 End stop 20 Device QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2023 / 0321845 A1

[0002] CN 217475260 U1

[0003] CN 117443896 A

[0003]

Claims

[1] Method for dismantling a traction battery (1) for a motor vehicle, wherein the traction battery (1) comprises a battery housing (7) and a battery module (2) inserted into a battery module receptacle (6) of the battery housing (7) and the battery module (2) is connected via a thermal conductor (12) to a cooling plate (8) which at least partially delimits the battery module receptacle (6), characterized by , that to remove the battery module (2) from the cooling plate (8) a suction cup (13) is placed on the cooling plate (8) on a side facing away from the battery module receptacle (6) and the cooling plate (8) is deflected towards the suction cup (13) by applying a vacuum to the suction cup (13). [2] Method according to claim 1, characterized by, that the suction bell (13) has a suction bell base (18) on its side facing away from the cooling plate (8), from which at least one end stop (19) projects towards the cooling plate (8), wherein the application of the vacuum is such that the cooling plate (8) rests against the end stop (19). [3] Method according to any one of the preceding claims, characterized by , that in addition to the deflection of the cooling plate (8) the battery module (2) is subjected to a disassembly force, so that it is displaced away from the cooling plate (8). [4] Method according to any one of the preceding claims, characterized by , that an edge of the suction bell (13) is provided with a seal (15) which is fluid-tight against the cooling plate (8). [5] Method according to any one of the preceding claims, characterized by , that a cooling plate (8) with at least one coolant channel (9) is used as the cooling plate (8). [6] Method according to any one of the preceding claims, characterized by , that a cooling plate (8) with at least one degassing opening (10) closed by means of a closure (11) is used as a cooling plate (8). [7] Method according to any one of the preceding claims, characterized by , that the suction bell (13) is positioned against the cooling plate (8) in such a way that it overlaps the degassing opening (10). [8] Method according to any one of the preceding claims, characterized by , that a thermally conductive adhesive is used as a thermal conductor (12) which connects the battery module (2) to the cooling plate (8) over a surface area. [9] Method according to any one of the preceding claims, characterized by , that a multi-component adhesive containing a thermally conductive filler is used as the thermally conductive adhesive. [10] Device (20) for dismantling a traction battery (1) for a motor vehicle, in particular for carrying out the method according to one or more of the preceding claims, wherein the traction battery (1) has a battery housing (7) and a battery module (2) inserted into a battery module receptacle (6) of the battery housing (7) and the battery module (2) is connected via a thermal conductor (12) to a cooling plate (8) which at least partially delimits the battery module receptacle (6), characterized by , that the device (20) has a suction bell (13) and is designed and configured to apply the suction bell (13) to the cooling plate (8) on a side facing away from the battery module receptacle (6) in order to remove the battery module (2) from the cooling plate (8) and to deflect the cooling plate (8) towards the suction bell (13) by applying a vacuum to the suction bell (13).

Images