Battery system for a vehicle, as well as a vehicle with a corresponding battery system and a method for dismantling a battery cell of a battery system

Abstract

Battery system (3) for a vehicle (1), with - at least one battery system component (5), and - at least one battery cell (4) which has a battery cell housing (8), characterized by, - at least one interconnection layer package (9, 10) by means of which the at least one battery cell (4) is connected to the at least one battery system component (5), wherein - that at least one compound layer package (9, 10) has a bottom side (13) which is materially connected to a housing side (14) of the battery cell housing (8), - that at least one compound layer package (9, 10) has a top surface (15) opposite the bottom surface (13), which is metallurgically connected to a component side (16) of the at least one battery system component (5), - comprising at least one compound layer package (9, 10) comprising at least one intermediate layer (17) which is arranged between the top (15) and the bottom (13), and wherein - which has at least one intermediate layer (17) comprising a material component (18), wherein the material component (18) is designed such that when an electrical voltage (U) is applied to the at least one intermediate layer (17), a material property of the material component (18) can be changed in such a way that the at least one intermediate layer (17) can be at least partially detached from the at least one compound layer package (9, 10), thereby allowing the at least one battery cell (4) to be removed from the at least one battery system component (5) without damage.

Description

[0001] The present invention relates to a battery system for a vehicle, comprising at least one battery system component and at least one battery cell, which has a battery cell housing.

[0002] Furthermore, the invention relates to a vehicle with a battery system. The invention also relates to a method for disassembling at least one battery cell of a battery system.

[0003] For the further development and improvement of electrically powered vehicles, such as electric vehicles, hybrid vehicles, or plug-in hybrid vehicles, more efficient battery systems are needed. These battery systems serve to supply electrical energy to the vehicle. A battery system can therefore be understood as a vehicle battery. Such a battery can consist of several electrically connected battery cells. For example, these battery cells can be lithium-ion cells. In particular, such a battery can be designed as a high-voltage battery, which can provide a voltage in the range of more than 60 volts, especially in the range of several hundred volts. With the help of the battery system, the electric powertrain of an electric vehicle can be supplied with electrical energy.

[0004] Furthermore, the requirements for disassembling such battery systems are becoming more extensive. It is essential that a battery or battery cell, as well as the individual cells, can be disassembled without damage. For example, in today's e-mobility, fully bonded battery systems are used to increase volumetric and gravimetric energy density. The fully bonded structure allows for the reduction of crash structures, such as longitudinal or lateral load paths. The saved installation space can then be used for additional battery cells.

[0005] Furthermore, full-surface bonding reduces the system's disassembly capability. Disassembly capability here refers to the three scenarios of rework, repair, and recycling. Without a disassemblable battery system, high costs arise due to the scrapping of the battery system in the event of damage.

[0006] Nowadays, adhesives are dissolved using solvents such as acetone. Heat can also be applied to soften or decompose the adhesive, for example, using microwave radiation, induction, or hot oil. Adhesives can also be modified, for example, by adding nanoparticles or expandable graphite. By using liquid adhesives or high-tensile-strength tapes, separation between the bonded surfaces can be achieved by applying tensile force.

[0007] However, these methods have the disadvantage of not providing access to the battery system, and the use of solvents, for example, can cause excessive damage or contamination to the battery system. The dissolution of adhesives due to heat can lead to thermal damage to surrounding components, such as from the melting point of high-strength adhesives. Similarly, surrounding components of the battery system can also be thermally damaged. The use of liquid adhesive or adhesive tape, for example, is only suitable for semi-structural bonds with a tensile force of up to 4 MPa.

[0008] For example, DE 10 2022 210 617 A1 discloses a battery system, in particular for supplying a motor vehicle drive with electrical energy, wherein the battery system has at least one battery cell, wherein the battery cell is attached by means of an adhesive bond.

[0009] Therefore, one object of the present invention is to simplify or improve the disassembly capability of a battery system.

[0010] This problem is solved by a battery system, a vehicle, and a method according to the independent patent claims. Meaningful further developments arise from the dependent patent claims.

[0011] One aspect of the invention relates to a battery system for a vehicle, with - In particular, at least one battery system component, and - In particular, at least one battery cell which has a battery cell housing, wherein - In particular, at least one interconnection layer package by means of which the at least one battery cell is connected to the at least one battery system component, wherein - In particular, at least one compound layer package has a bottom side which is materially bonded to a housing side of the battery cell housing, - In particular, that at least one compound layer package has a top side opposite the bottom side, which is materially bonded to a component side of the at least one battery system component, - In particular, that at least one compound layer package has at least one intermediate layer arranged between the top and bottom surfaces, and wherein - In particular, at least one intermediate layer comprises a material component, wherein the material component is designed such that when an electrical voltage is applied to the at least one intermediate layer, a material property of the material component can be changed in such a way that the at least one intermediate layer can be at least partially detached from the at least one compound layer package, thereby allowing the at least one battery cell to be removed from the at least one battery system component without damage.

[0012] The battery system according to the invention allows for the simpler and, in particular, non-destructive disassembly of individual components. Specifically, individual components of the battery system can be removed without damage. This is achieved through the, in particular, special material component of the intermediate layer. If the battery cell needs to be removed or disassembled non-destructively from at least one battery system component, the material properties of the component can be altered based on the applied electrical voltage, such that the intermediate layer can be at least partially, and in particular completely, detached or removed from the interconnected layer stack.By removing the intermediate layer, a loose or open area exists between the underside and the top side of the compound layer package, allowing the battery system component to be removed from the battery cell or vice versa.

[0013] In other words, by at least partially removing the intermediate layer from the interconnect layer assembly, a connection between the battery cell and the battery system component can be severed. In its intended application, the interconnect layer assembly allows for the creation of a connection, particularly a metallurgical bond, between the battery cell and the battery system component. Depending on requirements, especially during disassembly, a weak point or a break in the interconnect layer assembly can be introduced using the modifiable material component, so that the interconnect layer assembly is in a state that allows the at least one battery cell to be removed or disassembled from the at least one battery system component.

[0014] Only when an electrical voltage is applied, which may be a specific predetermined electrical voltage, can a weak point be specifically introduced into the connection layer package in order to be able to remove the battery cell from the battery system component without damage in the event of disassembly.

[0015] Due to the special design of the intermediate layer and, in particular, the material component, a disassembly process can be carried out as needed by applying an electrical voltage. Compared to the methods mentioned earlier, this eliminates the need for thermal energy input. Disassembly can therefore be performed without heat input. This allows the battery system to be used more efficiently and, in particular, for a longer lifespan, as individual battery cells or battery system components can be easily and, above all, non-destructively disassembled as required. For example, one battery cell can be replaced by another, or a battery cell can be removed for repair and subsequently reinserted.

[0016] The battery system can be an energy storage device such as a vehicle battery, an accumulator, or a high-voltage battery for electric vehicles. The battery cell can be, for example, a lithium-ion cell. The battery cell, in turn, has a battery cell housing, which allows it to be attached to the battery system component. The battery system component can be, for example, a housing structure, tension bands, a cooling plate, a battery system enclosure, or another component of the battery system. It is also conceivable that a battery cell can be connected to another battery cell within the battery system using the interconnection layer pack.

[0017] In other words, the interconnect layer package serves to fasten or connect components of the battery system to one another. With the aid of at least one interconnect layer package, the battery cell can be connected to at least one battery system component, at least partially, and in particular across its entire surface. A metallurgical bond can be used for this purpose. The interconnect layer package allows the battery cell to be connected to the battery system component in a predefined connection area. This means that such an interconnect layer package can be arranged at various connection areas between the battery cell and the battery system component to establish a connection.

[0018] The interconnect layer package can, for example, have a "sandwich structure" or "sandwich shape." The connection between the battery cell and the battery system component is achieved by bonding the housing side of the battery cell casing (i.e., a surface of the battery cell casing) to the underside (i.e., a surface of the interconnect layer package). This allows for a space-saving structure. The top side of the interconnect layer package can then be bonded to the component side (i.e., a surface of the battery system component). Thus, the battery system component and the battery cell can be connected via a thin, bonded connection. This is facilitated by the interconnect layer package, which is significantly thinner than both the battery system component and the battery cell.

[0019] The intermediate layer can be formed as a layer between the top and bottom surfaces and is also to be understood as a planar layer. The intermediate layer can contain the material component in such a way that the material component is, for example, uniformly distributed throughout the intermediate layer. The material component can also be present in different areas of the intermediate layer. In particular, the material component can be designed as an electrically activatable substance or material element. By applying an electrical voltage, the material property, structure, or other property of the material component can be altered or adjusted.This alters the properties of the intermediate layer, so that the intermediate layer, which is located between the top and bottom surfaces and is specifically connected to them, temporarily represents a weak point in the interconnected layer assembly. As a result, the connection between the top and bottom surfaces is no longer fully intact, which in turn allows the battery cell to be separated from the battery system component or vice versa.

[0020] The intermediate layer can be bonded to the underside by a material bond. The top side can also be bonded to the intermediate layer by a material bond. By at least partially separating or detaching the intermediate layer, there is no longer a permanent connection between the underside and the top side, allowing the battery system component to be easily disassembled from the battery cell, or vice versa.

[0021] In one embodiment, the material component is designed as an electrically releasable adhesive, wherein the electrically releasable adhesive is configured such that, upon application of an electrical voltage, the material properties can be altered based on ion diffusion induced within the electrically releasable adhesive. Thus, structural bonding, particularly structural cell bonding, of the battery cell to the battery system component can be achieved using an electrically releasable adhesive layer to maintain disassembly capability. Specifically, the intermediate layer can be referred to as the adhesive layer or releasable adhesive layer. The intermediate layer can, for example, consist entirely of the electrically releasable adhesive. It is also conceivable that the intermediate layer is coated with the electrically releasable adhesive in different areas.Thus, with the help of the intermediate layer, an adhesive layer can be created between the battery cell and the battery system component, and by applying an electrical voltage, for example, a weak point can be created within the electrically releasable adhesive.

[0022] The battery cell can be disassembled by electrically activating the intermediate layer, and especially the electrically releasable adhesive, particularly once. This introduces a weak point into the structural bond, for example, a weak point between the top and bottom surfaces. This allows for the simple, residue-free removal of the electrically releasable adhesive after disassembly, particularly from one side. This enables the straightforward automatic, semi-automatic, or manual application of a new electrically releasable adhesive, followed by reapplication and bonding with structural adhesive.Thus, after the application of voltage, the electrically releasable adhesive can be at least partially or partially removed, creating a weak point or a non-connected area between the top and bottom of the bonding layer package, which allows the battery cell to be removed from the battery system component, since the bonding layer package only forms a limited connection between the battery cell and the battery system component.

[0023] The electrically releasable adhesive can be a special hot melt adhesive based on polyamides. When an electrical voltage is applied, this adhesive loses at least some of its adhesive strength. The property of the electrically releasable adhesive is such that, when an electrical voltage is applied, ion diffusion, or diffusion within the adhesive itself, occurs. Diffusion is based on the thermal movement of particles. These particles can be atoms, molecules, or ions, for example. Diffusion also means that a uniform distribution of particles, and thus a complete mixing of two substances, can take place. When an electrical voltage is applied, ion diffusion can occur in the direction of the positive terminal towards the negative terminal or vice versa, depending on how the electrical voltage is applied.

[0024] For example, the polyamides in the adhesive can impart the necessary properties for its use as an adhesive, such as adhesive strength, adhesion, cohesion, melting behavior, and stability. The adhesive exhibits ionically conductive properties, so that when a voltage of a predetermined value is applied, diffusion occurs, thereby reducing the adhesive force, at least in certain areas. This allows the battery cell to be removed or disassembled from the battery system component without damage.

[0025] In one embodiment, a portion of the electrically releasable adhesive is arranged within a first region of the intermediate layer, which faces the top surface, and a further portion of the electrically releasable adhesive is arranged within a second region of the intermediate layer, which faces the bottom surface. Depending on the direction of current flowing through the intermediate layer, which determines the applied voltage, either the portion of the electrically releasable adhesive within the first region or the further portion within the second region is releasable. Thus, the electrically releasable adhesive can be distributed throughout the intermediate layer. It is also conceivable that the intermediate layer is composed entirely of the electrically releasable adhesive.

[0026] Depending on how the electrical voltage is applied to the interlayer, which is adjustable based on the direction of the current flowing through the interlayer, it can be determined whether the first part or the second part of the electrically releasable adhesive is dissolved. In other words, depending on the polarity of the applied voltage, it can be determined whether the interlayer dissolves towards the top or the bottom. This allows control over whether the adhesive dissolves in such a way that as few residues as possible remain on the battery cell or battery system component. In other words, it can be determined on which surface, where the adhesive is bonded, it should be dissolved.This can improve disassembly, as the electrically releasable adhesive can be dissolved in such a way that the disassembled battery cell has essentially no adhesive residue.

[0027] The battery system can incorporate a suitable electrical circuit to apply the electrical voltage. Electrical contacts can be configured so that the voltage is applied to the intermediate layer. The direction of the current can be controlled, so that the current is directed into the intermediate layer according to the area where the adhesive is intended to dissolve.

[0028] In particular, the intermediate layer is electrically conductive.

[0029] In one embodiment, the at least one interconnect layer package comprises an electrically conductive layer arranged between the intermediate layer and the underside. One side of the electrically conductive layer is in contact with the intermediate layer, and the conductive layer is electrically coupled to the component side of the at least one battery system component to apply an electrical voltage to the intermediate layer. With the aid of the electrically conductive layer, which can be a metallic layer, an electrical voltage can be applied between the component side of the battery system component and the conductive layer, thus inducing a current flow through the intermediate layer. This electrical coupling of the component side and the conductive layer allows the voltage to be applied to the intermediate layer.

[0030] For example, the electrically conductive layer can be made of aluminum foil. This aluminum foil can have a layer thickness of, for example, 30 µm.

[0031] Additionally, the electrically conductive layer and at least one battery system component can be short-circuited, particularly to each other, during normal operation of the battery system. Short-circuiting the electrically conductive components, specifically the electrical connection between the battery system component and the electrically conductive layer, prevents the intermediate layer from unintentionally detaching. Furthermore, during normal operation of the battery system, provided no disassembly is performed, the short circuit between the battery system component and the electrically conductive layer prevents leakage currents between the electrically conductive layer and the battery system component.Therefore, only when an electrical coupling or connection has been established between the electrically conductive layer and the battery system component can the voltage be applied to the intermediate layer, in order to then be able to disassemble the battery system.

[0032] In one embodiment, the at least one interconnect layer assembly includes a thermally conductive layer positioned between the electrically conductive layer and the underside. This thermally conductive layer could, for example, be a thermally conductive structural adhesive. This additional thermally conductive layer allows the interconnect layer assembly to also possess a thermally conductive property or function. This is advantageous, for instance, when the battery system component is a cooling plate or other heat-absorbing unit. The thermally conductive layer improves heat transfer from the battery cell to the battery system component via the interconnect layer assembly.

[0033] Additionally, at least one of the interconnect layer packages can include an insulating layer located between the thermally conductive layer and the underside. This insulating layer can, for example, be an optional cell insulation. This insulating layer can, for example, consist at least partially, and in particular entirely, of acrylic or PET.

[0034] In one embodiment, the at least one interconnect layer assembly further comprises a first and a second electrically conductive layer, wherein the first electrically conductive layer is arranged between the intermediate layer and the underside, and the second electrically conductive layer is arranged between the intermediate layer and the top side. One side of the first electrically conductive layer is in contact with a side of the intermediate layer facing the underside, and one side of the second electrically conductive layer is in contact with a side of the intermediate layer facing the top side. The first electrically conductive layer can be electrically coupled to the second electrically conductive layer to apply an electrical voltage to the intermediate layer. Thus, a wide variety of configurations of the interconnect layer assembly can be realized.This is particularly advantageous depending on the application and especially on the design of the battery system. The two electrically conductive layers allow the electrical voltage to be applied to the intermediate layer independently of the battery cell and the battery system component. For example, an electrical contact can be arranged on each of the two electrically conductive layers to apply the electrical voltage to the intermediate layer via these conductive layers. The two electrically conductive layers can be metallic. Thus, as required, the two electrically conductive layers can be electrically contacted, and the electrical voltage can be applied via these two conductive layers, so that it is also applied to the intermediate layer.

[0035] Additionally, the two electrically conductive layers can be short-circuited to each other during normal operation of the battery system. For example, the battery system can be designed so that an electrical circuit allows the electrical voltage to be applied to the intermediate layer only when disassembly is required. If the battery system is operating normally, i.e., supplying electrical energy to an electric vehicle, the two electrically conductive layers are short-circuited to each other, preventing any accidental or unintentional electrical activation of the intermediate layer and, in particular, the material component.

[0036] In one embodiment, the at least one compound layer package has a first and second thermally conductive layer, wherein the first thermally conductive layer is arranged between the first electrically conductive layer and the underside, and the second thermally conductive layer is arranged between the second electrically conductive layer and the topside.

[0037] The thermally conductive layers can be, for example, thermally conductive structural adhesives. These additional thermally conductive layers allow the interconnection layer package to possess an additional thermally conductive property or function. This is advantageous, for instance, when the battery system component is a cooling plate or other heat-absorbing unit. The thermally conductive layers improve heat transfer from the battery cell to the battery system component via the interconnection layer package.

[0038] Additionally, at least one of the interconnect layer packages can include an insulating layer located between the first thermally conductive layer and the underside. This insulating layer can, for example, be an optional cell insulation. This insulating layer can, for example, consist at least partially, and in particular entirely, of acrylic or PET.

[0039] In one embodiment, the underside of the at least one compound layer stack and the first housing side of the battery cell housing are arranged in abutting each other, and the top side of the at least one compound layer stack and the component side of the at least one battery system component are arranged in abutting each other. This allows for a compact structure with a significantly reduced thickness compared to the battery cell and the battery system component. In particular, the top and bottom surfaces of the compound layer stack are connected to the housing side and the component side in a continuous, surface-adhering manner. This enables a space-saving layered structure. Specifically, this allows for a "sandwich" structure.This allows the components of the battery system to be connected in a space-saving and efficient manner, resulting in a smaller installation space requirement for the battery system.

[0040] Another aspect of the invention relates to a vehicle with a battery system according to the previous aspect or an advantageous further development thereof.

[0041] The vehicle can be, in particular, an electrically powered vehicle such as an electric vehicle, hybrid vehicle, or plug-in hybrid vehicle. The vehicle has, in particular, an electric drive motor or an electric drivetrain to enable it to move. The electric drive motor can, in turn, be electrically supplied by the battery system according to the invention, which can, for example, be designed as a high-voltage battery.

[0042] It is also conceivable that the vehicle has several such battery systems according to the invention.

[0043] A further aspect of the invention relates to a method for disassembling at least one battery cell of a battery system according to one of the preceding aspects or an advantageous embodiment thereof. A predetermined electrical voltage is applied to the at least one intermediate layer of the at least one interconnection layer package by means of which the at least one battery cell is connected to the at least one battery system component, wherein the material properties of the material component of the at least one intermediate layer are changed depending on the applied electrical voltage such that the at least one intermediate layer is at least partially detached from the at least one interconnection layer package in order to disassemble the at least one battery cell from the at least one battery system component without damage.Thus, the specially designed intermediate layer, which, for example, incorporates an electrically conductive adhesive as a material component, can be modified to allow the battery cell to be removed or extracted without damage. This makes disassembly of a battery system simpler and, in particular, more efficient.

[0044] In particular, the procedure just described can be used to carry out the disassembly of a battery system, as explained at the beginning.

[0045] Advantageous embodiments of one aspect of the invention are to be regarded as advantageous embodiments of one or all other aspects of the invention. The reverse is also true.

[0046] The invention also includes further developments of the vehicle and the method according to the invention, which have features already described in connection with the further developments of the battery system according to the invention. For this reason, the corresponding further developments of the vehicle and the method according to the invention are not described again here.

[0047] The invention also includes combinations of the features of the described embodiments.

[0048] The following describes exemplary embodiments of the invention. This is illustrated by: Fig. 1 a schematic representation of a vehicle which has a battery system; Fig. 2 a schematic installation situation of the battery system in the vehicle; Fig. 3 an exemplary representation of a connection layer package with which components of the battery system can be connected in such a way that individual components can be disassembled without damage if necessary; Fig. 4 starting from the Fig. 3 a further embodiment of the connection layer package; and Fig. 5 a schematic sequence regarding a dismantling process of the aforementioned battery system.

[0049] The embodiments described below are preferred embodiments of the invention. In these embodiments, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described.

[0050] In the figures, functionally identical elements are each provided with the same reference symbols.

[0051] In the Fig. Figure 1 shows a schematic representation of a vehicle 1. The vehicle 1 can be an electrically powered vehicle. In particular, the vehicle 1 is designed as an electric vehicle or a hybrid vehicle. For this purpose, the vehicle 1 has at least one electric drive unit 2, in particular an electric motor. In order to supply this with electrical energy, the vehicle 1 has at least one battery system 3, in particular an electric battery system. With the help of the battery system 3 or several such battery systems, electrical energy can be provided for the electric drive unit or other electrical systems in the vehicle 1.

[0052] To improve the efficiency of vehicle 1 with regard to e-mobility and, in particular, to increase the service life of the reusable battery system 3, it is advantageous if the battery system 3 is designed to be easier to disassemble, especially for repair, replacement, rework, or recycling. The present invention advantageously addresses this need, as individual components of the battery system 3 according to the invention can be disassembled non-destructively. This will be explained more clearly in the following figures.

[0053] In the Fig. Figure 2 shows a schematic representation of an installation situation for the battery system 3. Here, the battery system 3 can be mounted in the vehicle 1. The battery system 3 includes, in particular, at least one battery cell 4, such as a lithium-ion battery cell. The at least one battery cell 4, or several such battery cells, can be connected in series or in parallel. In addition to at least one battery cell 4, the battery system 3 includes at least one battery system component 5. This battery system component 5 can, for example, be a battery housing. Other components or parts of the battery system 3 are also to be understood as battery system components 5. The battery system 3 can, for example, be mounted between a vehicle component 6, such as an assembly (ZSB) upper shell, and an underride guard 7.This underride guard 7 is in particular a protective device for the battery system 3 against the vehicle underbody.

[0054] The battery cell 4 can have a battery cell housing 8 to protect it from external influences. This housing can be a hard case. A hard case consists, for example, of two parts: the housing container ("can") and the cell cover ("cap plate"). The battery cell housing 8 can, for example, be made of aluminum.

[0055] In order to enable the battery cell 4 to be removed non-destructively for disassembly, the battery cell 4 is connected to the battery system component 5 via a connection layer package 9. Further such connection layer packages 10 are also possible. As shown in the Fig. As shown in Figure 2, a positive-locking connection between the battery cell 4 and the battery system component 5 is achieved using the two connection layer packages 9 and 10. These special connection layer packages 9 and 10 are arranged or formed at specific connection areas 11 and 12 between the battery cell 4 and the battery system component 5. Thus, depending on the current conditions or dimensions of the battery system 3 and the available space in the vehicle 1, the positive-locking connection between the battery cell 4 and the battery system component 5 can be implemented appropriately. In the following Fig. Section 3 explains the connection layer package 9, 10. A corresponding schematic cross-sectional view is shown.

[0056] To establish a connection between the battery cell 4 and the battery system component 5, the interconnection layer package 9, 10 is bonded to a bottom surface 13 and a housing side 14 of the battery cell housing 8. In addition to the bottom surface 13, the interconnection layer package 9, 10 has a corresponding opposite top surface 15. The top surface 15 is bonded to a component side 16 of the battery system component 5. As shown schematically in the Fig. As shown in Figure 3, the compound layer package 9, 10 has a "sandwich structure". Thus, the two sides of the compound layer package 9, 10 are each connected to a side of the battery cell 4 and the battery system component 5, so that the battery cell 4 and the battery system component 5 are in turn materially bonded together.

[0057] As previously explained, to enable non-destructive disassembly of the battery cell 4 from the battery system component 5, the interconnection layer package 9, 10 has a special intermediate layer 17. This intermediate layer 17 is arranged between the bottom surface 13 and the top surface 15. The intermediate layer 17 can be bonded to the top surface 15 and / or bottom surface 13, in particular by a metallurgical bond. For non-destructive disassembly, the intermediate layer 17 has a material component 18. This material component 18 is designed such that when an electrical voltage U is applied to the at least one intermediate layer 17, a material property of the material component 18 can be changed so that the at least one intermediate layer 17 can be at least partially detached or removed from the at least one interconnection layer package 9, 10.Thus, the connection between battery cell 4 and battery system component 5 can be softened or dissolved in order to remove battery cell 4 from battery system component 5 without damage.

[0058] For the non-destructive and, in particular, simpler disassembly of the battery cell 4, the material component 18 is an electrically releasable or electrically activatable adhesive. This electrically releasable adhesive has a composition which, when an electrical voltage is applied, causes the adhesive to at least partially lose its adhesive strength, allowing the bond to be broken. Specifically, applying the electrical voltage U can induce ion diffusion in the adhesive, thereby altering the material properties.

[0059] In order to apply the electrical voltage U, so that in particular a current flow exists in the intermediate layer 17, the interconnection layer package 9, 10 can be configured according to the embodiments of the Fig. 3. The electrically conductive layer 19 has an electrically conductive layer. This electrically conductive layer 19 can be a metallic layer or a metal layer. This electrically conductive layer 19 is arranged between the intermediate layer 17 and the underside 13. One side can be in contact with the intermediate layer, in particular over a surface. As shown in the Fig. As shown in Figure 3, the voltage U can be applied between the component side 16 of the battery system component 5 and the electrically conductive layer 19, whereby the voltage U is also applied to the intermediate layer 17.

[0060] For applying the voltage U, the battery system 3 can have a switching unit 20. Depending on requirements, the switching unit 20 can establish an electrical connection between the component side 16 and the electrically conductive intermediate layer 19. For this purpose, the switching unit 20 can include switching elements and a circuit. To ensure that the intermediate layer 17 is only partially disassembled in the event of a disassembly requirement and not accidentally, a corresponding protective mechanism is provided. In normal operation of the battery system 3, the electrically conductive layer 19 is short-circuited with the battery system component 5, preventing any current from flowing and thus preventing an unwanted voltage from occurring.

[0061] For example, the interconnection layer package 9, 10 can have at least one thermally conductive layer 21. This layer facilitates heat transfer between the battery cell and the battery system component 5, thus enabling heat dissipation from the battery cell. This thermally conductive layer 21 can, for example, be designed as a structural adhesive. In particular, the thermally conductive layer 21 can be arranged, for example, between the electrically conductive layer 19 and the underside 13. Depending on the configuration of the battery system 3, the interconnection layer package 9, 10 can also have an insulating layer 22, for example, cell insulation. This layer can be arranged between the thermally conductive layer 21 and the underside 13. This results in a layer structure that can be described as a "sandwich structure".

[0062] For example, the compound layer package 9, 10 can have a layer thickness in the range of 0.3 mm to 1.5 mm or 0.2 mm to 2.0 mm. In particular, the thickness d (cf. Fig. 5) have a maximum thickness of 3 mm, in particular 5 mm. The thickness of the intermediate layer 17 can, for example, be between 80 µm and 120 µm, in particular 100 µm. The thickness of the electrically conductive layer 19 can, for example, be between 10 µm and 20 µm, in particular 15 µm.

[0063] For example, the electrically releasable adhesive can be distributed as material component 18 within the intermediate layer 17. This can be understood as either the adhesive completely forming the intermediate layer 17 or the intermediate layer 17 having different regions in which a specific amount of the adhesive is present.

[0064] In the Fig. Figure 4 shows a further embodiment of the compound layer packages 9, 10. The explanations regarding the following apply here. Fig. 3, where several layers of the compound layer packages 9, 10 are present. Here, the compound layer package 9, 10 has a first and second electrically conductive layer 24, 25, i.e., two electrically conductive layers. The first conductive layer 24 is located between the intermediate layer 17 and the bottom surface 13, and the second electrically conductive layer 25 is located between the intermediate layer 17 and the top surface 15. A side 26 of the first electrically conductive layer 24 can be located against a side 27 of the intermediate layer 17 facing the bottom surface 13. A side 28 of the second electrically conductive layer 25 can be located against a side 29 of the intermediate layer 17 facing the top surface 15. Thus, the two electrically conductive layers 24, 25 enclose the intermediate layer 17. Contrary to the embodiment in the Fig. 3, in which the electrical voltage U between the battery system component 5 and the electrically conductive layer 19 therein was realized, is implemented in the embodiment in the Fig. 4. The electrical voltage U is established between the two electrically conductive layers 24, 25. Thus, for the non-destructive removal of the battery cell 4, no current flows between the layers and the battery system component 5. As already described in the Fig. As explained in section 3, the electrical connection between the two electrically conductive layers 24, 25 present here can also be short-circuited during the intended operation of the battery system 3. Optionally, the connection layer package 9, 10 can again have a first and second thermally conductive layer 30, 31. The first thermally conductive layer 30 can be arranged between the first conductive layer 24 and the underside 13. The second thermally conductive layer 31 can, in turn, be arranged between the second electrically conductive layer 25 and the top side 15. An insulating layer can also be provided in this embodiment. Here, it is also arranged between the first thermally conductive layer 30 and the underside 13.

[0065] The individual layers of the compound layer package 9, 10 can each be arranged in a perpendicular relationship to the surfaces of components 4, 5. In the following Fig. Section 5 describes an exemplary procedure for dismantling battery system 3.

[0066] First, it should be briefly explained that the components of battery system 3 can initially be connected using the interconnection layer package 9, 10. For the aforementioned disassembly requirements, the components of battery system 3 can be detached accordingly. In particular, an electrically detachable intermediate layer, i.e., intermediate layer 17, can be used for structural bonding, especially near the cells, within battery system 3 to make it detachable for disassembly processes such as rework, repair, or recycling. The use of structural adhesives serves to integrate the cells or other components into the force-load path of the vehicle 1 in the event of external crash or operational loads on battery system 3. Such structural adhesives can, for example, be used to bond the other layers of the interconnection layer package 9, 10 to each other independently of intermediate layer 17.Such an adhesive can in turn be used to bond other components of the battery system 3, in particular to enable a flat and space-saving design of the battery system 3. The bond can also exhibit thermal conductivity when structurally connecting the battery cell 4 to a cooling plate. This can be achieved, for example, with the thermally conductive layers 21, 30, 31. In particular, in the... Fig. 5. To simplify the design, the following applies: Fig. Figure 3 shows this. Alternatively, the battery cell 4 can be bonded to surrounding battery system components such as housing structures, tension bands, etc. using conventional adhesive bonding. Alternatively, battery system components of battery system 3 can also be joined using this method.

[0067] In an optional first step S1, a voltage U can be applied to the intermediate layer 17. For example, the voltage U could be 48 volts. The current flowing through the intermediate layer 17 could then be, for example, 3 amperes. The primary purpose of applying the voltage U is to activate component 18, which is the electrically releasable adhesive. This is achieved by applying the voltage to the surrounding components of the intermediate layer 17. This can be done either between the two intermediate layers 24 and 25, or between layer 19 and the battery system component 5.

[0068] After the voltage U is applied, in an optional subsequent step S2, the adhesive is detached on one side by ion diffusion. By reducing the interfacial adhesion, the adhesive can be detached or removed. This creates, for example, weak points in the sandwich structure with respect to the bonded layer package 9, 10, allowing the battery cell 4 or similar component to be disassembled from the joined component, such as the battery system component 5, without damage, for example, at room temperature.

[0069] In an optional subsequent step S3, the adhesive is detached on one side, creating a gap or weak point in the bonding layer package 9, 10 to separate the two components 4, 5. The voltage and current can be selected to avoid electrical damage to the battery cell 4 or the surrounding components. Depending on the electrical polarity with respect to the applied voltage U, the position of the intermediate layer 17 on one of the joining partners can be freely chosen. As in the Fig.As shown in Figure 5 under step S3, the intermediate layer 17 is at least partially in contact with the battery system component 5. This can be varied depending on the polarity of the applied voltage. For example, part of the electrically releasable adhesive can be located within a first region 32 of the intermediate layer 17, which faces the top surface 15, and another part within a second region 33 of the intermediate layer 17, which faces the bottom surface 13. Depending on the direction of current flowing through the intermediate layer 17, the ion diffusion or differential can be adjusted. Thus, it can be determined in advance where a substantially adhesive-free surface should be present.Above all, this should be chosen so that battery cell 4 is as free as possible from electrically soluble adhesive.

[0070] After disassembly, the intermediate layer 17 can be removed from the selected substrate surface without leaving any residue. For example, the intermediate layer 17 can correspond to the top surface 15. Thus, the top surface 15 is connected to the component side 16 of the battery system component 5 with the help of the intermediate layer 17 and the releasable adhesive present there. Reference symbol list 1 vehicle 2 electric drive units 3 battery system 4 battery cells 5 Battery system component 6 Vehicle component 7 Underride protection 8 battery cell housings 9, 10 connection layer packages 11, 12 connection areas 13 Underside of the compound layer package 14 Housing of the battery cell housing 15 Top 16 Component side of the battery system component 17 Intermediate shift 18 Material components 19 electrically conductive layer 20 side of the electrically conductive layer 21 thermally conductive layer 22 Insulation layer 23 Switching unit 24, 25 first and second electrically conductive layer 26th page of the first electrically conductive layer 27th page of the intermediate layer 28 Page of the second electrical layer 29 a side of the intermediate layer facing upwards 30, 31 first and second thermally conductive layer 32, 33 first and second area of ​​the intermediate layer d layer thickness

Claims

Battery system (3) for a vehicle (1), comprising at least one battery system component (5), and at least one battery cell (4), which has a battery cell housing (8), characterized by: at least one interconnection layer package (9, 10), by means of which the at least one battery cell (4) is connected to the at least one battery system component (5), wherein: the at least one interconnection layer package (9, 10) has a bottom surface (13), which is materially connected to a housing side (14) of the battery cell housing (8); the at least one interconnection layer package (9, 10) has a top surface (15) opposite the bottom surface (13), which is materially connected to a component side (16) of the at least one battery system component (5); the at least one interconnection layer package (9, 10) has at least one intermediate layer (17), which is arranged between the top surface (15) and the bottom surface (13).and wherein the at least one intermediate layer (17) comprises a material component (18), wherein the material component (18) is designed such that when an electrical voltage (U) is applied to the at least one intermediate layer (17), a material property of the material component (18) can be changed in such a way that the at least one intermediate layer (17) can be at least partially detached from the at least one compound layer package (9, 10), thereby allowing the at least one battery cell (4) to be removed from the at least one battery system component (5) without damage. Battery system (3) according to claim 1, characterized in that the material component (18) is designed as an electrically releasable adhesive, wherein the electrically releasable adhesive is designed such that the material property can be changed when the electrical voltage (U) is applied on the basis of an ion diffusion caused in the electrically releasable adhesive. Battery system (3) according to claim 2, characterized in that a part of the electrically releasable adhesive is arranged within a first region (32) of the intermediate layer (17), which is directed towards the top (15), and / or a further part of the electrically releasable adhesive is arranged within a second region (33) of the intermediate layer (17), which is directed towards the bottom (13), wherein, depending on the current direction of a current flowing through the intermediate layer (17), on the basis of which the electrical voltage (U) can be applied, the part of the electrically releasable adhesive within the first region (32) or the further part of the electrically releasable adhesive within the second region (33) is releasable. Battery system (3) according to claim 1, 2 or 3, characterized in that the at least one interconnection layer package (9, 10) has an electrically conductive layer (19) which is arranged between the intermediate layer (17) and the underside (13), wherein a side (20) of the electrically conductive layer (17) is arranged in contact with the intermediate layer (17), and wherein the electrical layer (19) is electrically coupleable with the component side (16) of the at least one battery system component (5) in order to apply the electrical voltage (U) to the intermediate layer (17), in particular the electrically conductive layer (19) and the at least one battery system component (5) are short-circuited in an intended operation of the battery system (3). Battery system (3) according to claim 4, characterized in that the at least one compound layer package (9, 10) has a thermally conductive layer (21) which is arranged between the electrically conductive layer (19) and the underside (13), in particular the at least one compound layer package (9, 10) has an insulating layer (22) which is arranged between the thermally conductive layer (21) and the underside (13). Battery system (3) according to claim 1, 2 or 3, characterized in that the at least one compound layer package (9, 10) comprises a first and second electrically conductive layer (24, 25), wherein the first electrically conductive layer (24) is arranged between the intermediate layer (17) and the bottom (13) and the second electrically conductive layer (25) is arranged between the intermediate layer (17) and the top (15), wherein a side (26) of the first electrically conductive layer (24) is abutting a side (27) of the intermediate layer (17) facing the bottom (13) and a side (28) of the second electrically conductive layer (25) is abutting a side (29) of the intermediate layer (17) facing the top (15), and wherein the first electrically conductive layer (24) is electrically coupleable with the second electrically conductive layer (25) to control the electrical voltage (U) across the intermediate layer (17). to createin particular the two electrically conductive layers (24, 25) are short-circuited during normal operation of the battery system (3). Battery system (3) according to claim 6, characterized in that the at least one compound layer package (9, 10) has a first and second thermally conductive layer (30, 31), wherein the first thermally conductive layer (30) is arranged between the first electrically conductive layer (24) and the bottom (13) and the second thermally conductive layer (31) is arranged between the second electrically conductive layer (25) and the top (15), in particular the at least one compound layer package (9, 10) has an insulating layer (22) which is arranged between the first thermally conductive layer (30) and the bottom (13). Battery system (3) according to one of the preceding claims, characterized in that the underside (13) of the at least one compound layer package (9, 10) and the housing side (14) of the battery cell housing (8) are arranged abutting each other and the top side (15) of the at least one compound layer package (9, 10) and the component side (16) of the at least one battery system component (5) are arranged abutting each other. Vehicle (1) with a battery system (3) according to one of the preceding claims. Method for disassembling at least one battery cell (4) of a battery system (3) according to any one of the preceding claims 1 to 8, wherein: - a predetermined electrical voltage (U) is applied to the at least one intermediate layer (17) of the at least one interconnection layer package (9, 10) by means of which the at least one battery cell (4) is connected to the at least one battery system component (5), - the material properties of the material component (18) of the at least one intermediate layer (17) are changed depending on the applied electrical voltage (U) such that the at least one intermediate layer (17) is at least partially released from the at least one interconnection layer package (9, 10) in order to disassemble the at least one battery cell (4) from the at least one battery system component (5) without damage.

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