Method and apparatus for making the interior of closed battery housings accessible, especially for electric vehicles

Abstract

The invention relates to a method for making the interior of closed battery housings (1), in particular of electric vehicles, especially during battery recycling and / or repair, in which at least an edge region of a lid (2) or an outer surface of the closed battery housing (1), preferably under the influence of cold (11, 14), is mechanically separated from the rest of the battery and lifted off in a tongue-like manner, subsequently a holding device (3) is attached to this tongue-like lifted edge region (16) along the edge of the lid (2), which exerts a force (17) directed away from the battery housing (1) on the lifted edge region (16) of the lid (2) via a lifting device (15).and in the area of ​​the root (18) of the tongue-shaped raised edge region (16), further sections of the cover (2) are mechanically detached from the battery by the application of cold (14) and lifted from the battery by the force of the lifting device (15) until the cover (2) is substantially completely detached from the battery and separable from the battery housing (1). A suitable device for this purpose is also specified.

Description

[0001] The invention relates to a method for making the interior of closed battery housings accessible according to the preamble of claim 1 and to a device suitable for carrying out the method according to the preamble of claim 15.

[0002] The production of batteries has gained increasing importance due to the mass production of electric vehicles. Furthermore, the ranges required for customer acceptance of electric mobility necessitate high battery capacities, requiring the interconnection of numerous identical individual cells to form a vehicle battery that are then operated together. Various battery and cell designs are currently in use for this purpose.

[0003] Due to the weight of such batteries or accumulators in a vehicle battery, it is necessary to arrange and secure the individual cells in such a way that the arrangement is compact and stable even under dynamic driving conditions. These individual cells are either inserted into appropriate, sometimes complex, holders and individually fastened and connected. Increasingly, arrangements of individual cells are being used in vehicle batteries that are permanently connected to each other, forming a kind of solid block. Such a blocking of individual cells can be achieved, for example, by gluing or potting the individual cells together after they have been arranged in the desired configuration. This is the case, for example, with the company...Tesla is known for vehicle battery designs in which the individual cells consist of cylindrical units with a round cross-section, and a large number of such cylindrical units are arranged in a matrix-like configuration within a battery box, spaced apart from one another. The individual cells thus form, for example, a row-like and column-like array of cylindrical units, with the cylindrical edges of each cell maintaining a gap between them. A liquid, thermally conductive adhesive is injected into this usually small gap, for example, by injection. This adhesive fills the space and, after curing, fixes the individual cells in their spaced arrangement relative to each other.

[0004] However the individual cells within the battery are arranged and secured, the battery is typically sealed off from the environment by a battery box that completely encloses and encapsulates the cell array. Such battery boxes are usually made of highly thermally conductive materials, such as aluminum sheets, and are robust enough to protect the individual cells even against mechanical stresses, such as those caused by accidents, and ideally remain sealed even after an accident. This also reduces the fire risk of such batteries, which are particularly flammable due to the materials used, such as lithium.

[0005] The battery boxes are typically designed so that the individual cells can be installed from one direction within the trough-shaped, sealed battery box, connected to each other, and then glued or potted as described. The battery box is then sealed at the open installation side with a lid. To ensure the lid is attached to the battery box as airtight as possible, it is glued to at least the corresponding edges of the battery box.In batteries formed from individual cells that are glued and potted together, the battery cover is usually glued across its entire inner surface. The simplest way to achieve this is to fill the battery box with the potting compound used to bond the individual cells together, ensuring that it comes into contact with the inner surface of the cover, which is placed on top of the battery box. This directly bonds the cover to the potting compound between the individual cells. As a result, once the adhesive has cured, the battery box, individual cells, and cover form a largely completely bonded unit that is mechanically very stable.

[0006] However, this design has a significant disadvantage: when these types of vehicle batteries are later recycled, the individual cells must be separated to access and recover the expensive and limited battery raw materials. Furthermore, during battery repairs, it can be advantageous to be able to selectively replace individual cells within such a spaced arrangement, particularly those that are defective or no longer functioning properly. For this to work, however, individual cells, encapsulated as described, must be able to be removed from the battery assembly with minimal disruption to the rest of the vehicle battery.

[0007] However, to access the interior of the battery box containing the individual cells to be recycled or replaced without having to destroy the entire battery, for example by shredding it, the battery box lid must be able to be opened again. For lids that are only glued at the edges, this may be possible using thermal processes with necessary temperatures of approximately 250 °C (the temperature inside the lid must not exceed 80 °C). These processes either heat the contact area between the edge of the battery box and the battery box lid, thus softening the adhesive, or cool the contact area between the edge of the battery box and the battery box lid significantly, thus making the adhesive brittle.In this edge area with the softened or brittle adhesive, the contact between the edge of the battery box and the battery box lid can then be mechanically separated, and the battery box lid can then be removed from the battery box.

[0008] Separating bonded components, such as the individual cells of a vehicle battery, is often problematic. For example, WO 2021 / 259424 A1 states that body components can be separated by applying cold and a brief mechanical impact. The cold reduces the adhesive's strength to such an extent that the components can be easily separated, for example, by lightly striking the adhesive joint with a chisel. Surrounding components and adhesive bonds are not damaged, and the adhesive bond's full functionality is completely restored after a brief warming at ambient temperature.

[0009] To lower the temperature of objects, a cooling medium is generally used. This medium is first cooled to a low temperature and then brought into direct or indirect contact with the object to transfer the cold, for example, liquid carbon dioxide after expansion as a cooling medium in the form of cold gas containing dry ice. It is known, for instance, from DE 10 2007 052 ​​390 B4, to expand liquid carbon dioxide into carbon dioxide gas with dry ice particles in order to cool a surface to temperatures of approximately -30°C. During expansion, the liquid carbon dioxide becomes a mixture of carbon dioxide gas and carbon dioxide snow, with the carbon dioxide snow significantly improving the transfer of cold to the surface being cooled.Furthermore, it is known to add a cold-stable liquid to the area of ​​evaporation of the liquid carbon dioxide, which enables further cooling and particularly intensive transfer of the cold to the surface to be cooled.

[0010] With battery box covers that are glued over the entire surface or over larger sections as described above, a small-area separation is not possible; moreover, thermal heating inside the cover is not permissible due to the thermally sensitive individual cells underneath.

[0011] The object of the present invention is therefore to provide a method and a device with which safe and effective access to the interior of closed battery housings is made possible in order to enable recycling or repair of the vehicle battery.

[0012] The solution to the problem according to the invention is achieved with respect to the method by the characterizing features of claim 1 and with respect to the apparatus by the characterizing features of claim 15, each in conjunction with the features of the associated preamble. Further advantageous embodiments of the invention are set forth in the dependent claims.

[0013] The method according to the invention is based on a method for making the interior of closed battery housings accessible, in particular those of electric vehicles, especially during recycling and / or repair of the battery.Such a generic method is further developed by mechanically separating at least an edge region of a lid or an outer surface of the closed battery housing from the rest of the battery, preferably under the influence of cold, and lifting it off in a tongue-like manner; attaching a holding device to this tongue-like lifted edge region along the edge of the lid, which exerts a force directed away from the battery housing on the lifted edge region of the lid via a lifting device; and in the area of ​​the root of the tongue-like lifted edge region, further sections of the lid are mechanically detached from the battery by the application of cold and lifted from the battery by the force of the lifting device until the lid is essentially completely detached from the battery and separable from the battery housing.This involves starting with a previously detached edge of the battery cover, or another surface of the battery housing, which may have been manually separated from the housing. This edge is then loosened to the point where a tongue-shaped section of the cover is exposed. This manual loosening of the edge can occur under cold conditions, which can cause the adhesive between the cover and the battery housing or the battery interior to become brittle. Furthermore, sudden mechanical stress at the joint between the cover and the battery housing or the battery interior can break the bond. Once such a tongue-shaped section has been manually separated, a holding device can be attached to it, for example, along the edge.This holding device then serves to mechanically couple a lifting device, which exerts a force away from the battery housing onto the lifted edge of the cover via the holding device. This force serves to further separate the cover from the battery housing or the battery interior. This separation is achieved mechanically in the area of ​​the base of the tongue-shaped lifted edge, by applying cold, for example, through shock and impact loads on the brittle adhesive between the cover and the battery housing or the battery interior at further sections of the cover. Figuratively speaking, the cover is separated from the battery housing or the battery interior by the application of cold and the shock and impact loads on the brittle adhesive.The adhesive is peeled away from the inside of the battery and thus successively separated by lifting the cover from the battery under the force of the lifting device until the cover is essentially completely detached from the battery and separable from the battery box. The inventive method requires only local mechanical stress on the cold-embrittled adhesive, with the result that the adhesive bond between the cover and the battery housing or the inside of the battery is always partially loosened, and the action of the lifting device holds the cover in a position detached from the battery. The lifting action of the device supports and secures the local separation of the embrittled adhesive.By successively shifting the point of application of mechanical stress onto the cold-embrittled adhesive, the adhesive can, figuratively speaking, be separated from the cover at the base of each tongue-shaped section, allowing the cover to be gradually removed. Handling the detached section of the cover is simplified by the removal device, as it is always moved away from the battery housing and thus away from the area of ​​mechanical stress. In this way, even large, fully bonded covers can be removed from the battery with manageable effort, providing access to the interior of the battery housing with minimal damage.

[0014] It is particularly advantageous if the holding device is glued to the edge of the lid in the area of ​​the tongue-shaped, raised rim. This can be done, for example, with a silicone adhesive or other suitable adhesive substances with lower glass breakage temperatures, ensuring a continuous bond between the edge of the lid and the holding device.

[0015] In another embodiment, it is also conceivable that the retaining device clamps the lid in the area of ​​the tongue-shaped, raised edge. For example, the retaining device could grip the lid in this area and clamp it between itself. Alternatively, the lid's edge and the retaining device could be screwed together, perhaps using a threaded rod attached to the retaining device with screws, clamping the tongue-shaped, raised edge. This would create a mechanically stable and durable connection between the lid and the retaining device that requires no adhesive curing and can be easily disassembled.

[0016] It is advantageous if the cover is pre-cooled, at least in some areas, from outside the battery before being removed from the inside. Full or partial pre-cooling of the adhesive, for example, using cooling devices such as cooling elements, cooling pads, or cooling baths attached to the outside of the cover, allows for easy cooling of the adhesive to be removed. This means that any additional cooling effect applied to the area of ​​mechanical stress on the adhesive bond only needs to provide the final cooling, thus enabling a faster working process.

[0017] It is advantageous to introduce additional cold into the area between the lid and the battery interior. This cold selectively embrittles the adhesive between the lid and the battery interior in the areas that are to be separated mechanically. This way, only a particularly strong cooling of the adhesive is required locally, in order to reduce the embrittlement to the level that is most advantageous for mechanical separation, ideally within the respective working area. In one embodiment, the cold applied when separating the lid from the battery interior can be introduced directly into the area of ​​the base of the tongue-shaped raised edge, preferably directly at the adhesive in the base area, thus acting directly on the adhesive. However, it is also conceivable to introduce the cold from the side of the lid opposite the adhesive bond, thereby cooling the bond indirectly.A combination of both options is also conceivable.

[0018] In an advantageous embodiment, it is conceivable that the mechanical separation between the cover and the interior of the battery is caused by impact- or shock-resistant separation tools, in particular chisels. The impact- or shock-resistant loading of cooled and thus embrittled adhesive bonds is generally known and allows, for example in the case of bonded body parts, a gentle separation of such adhesive bonds without permanently impairing the material properties.

[0019] It is conceivable that the separating tool could be moved manually or automatically in the area between the battery's interior and the cover. Manual guidance of the separating tool has the advantage of allowing for targeted work depending on the separation progress, but requires the work of an operator and a certain level of experience. Automated guidance of the separating tool, for example, always along the base of the respective tongue-shaped, lifted edge section, is more economical, but may require additional monitoring to ensure that the cover is separated correctly.

[0020] Furthermore, it is conceivable that the mechanical separation between the lid and the battery interior is achieved through shock and / or vibration, preferably vibration in the area of ​​the lid, particularly in the area of ​​the tongue-shaped, raised edge of the lid. For example, a vibrating tool can set the lid or sections of the lid itself into vibration in such a way that the brittle adhesive in the respective area of ​​the bond to be separated is subjected to such mechanical stress that it tears, separating the lid and the battery interior at that point. This further protects the battery interior, as only the lid is subjected to mechanical stress, without a tool being able to penetrate the battery interior and potentially damage any functional components located there.

[0021] It is definitely advantageous if a nozzle for introducing cold into the area between the battery interior and the cover is moved together with the separation tool. This ensures that the cold is always automatically introduced into or near the respective separation area on the cover or in the root area, without requiring any additional handling.

[0022] It is also conceivable that the cold is introduced by means of sublimating liquid carbon dioxide, preferably with the addition of a cold-stable liquid, via a nozzle, preferably into the area between the inside of the battery and the lid.

[0023] The invention further describes a device for making the interior of closed battery housings accessible, in particular of electric vehicles, especially during recycling and / or repair of the battery, in particular for carrying out the method according to claim 1, wherein at least an edge region of a lid or an outer surface of the closed battery housing is mechanically separated from the rest of the battery and lifted off in a tongue-like manner, preferably under the influence of cold.Such a device is further developed by providing a holding device that can be attached to the raised edge of the lid along the tongue-shaped, raised edge, and a lifting device that engages the holding device and thus the lid in such a way that a force directed away from the battery housing acts on the raised edge of the lid, wherein at least one separating tool engages in the area of ​​the root of the tongue-shaped raised edge while applying cold and mechanically releases further sections of the lid from the battery, and the force of the lifting device lifts these released sections from the battery until the lid is essentially completely detached from the battery and separated from the battery housing.The essential features and advantages of such a device have already been explained in connection with the method described above and are hereby referenced for the device to avoid repetition.

[0024] In a further embodiment, it is conceivable that the holding device has an angle, preferably L-shaped, with one leg attached to the previously tongue-shaped, raised edge of the lid and the other leg attached to a lifting device. Designing the holding device as, for example, an L-shaped angle, has the advantage that one leg of the angle can be used for securing it to the raised edge of the lid, while the other leg provides a convenient point of engagement for the lifting device.

[0025] In one conceivable embodiment, the holding device can have a clamping element on the leg that is positioned on the tongue-shaped, raised edge of the lid. This clamping element secures the raised edge of the lid to the holding device, for example, by having a rod-like clamping bracket that presses the raised edge of the lid against the holding device. The holding device can thus be easily attached to the raised edge of the lid for preparation, but also detached again after the separation process is complete, while still ensuring reliable force transmission from the lifting device to the lid.

[0026] In a further embodiment, it is conceivable that the lifting device includes a pulling mechanism that pulls the lifted edge of the lid away at an angle to the lid surface, at least with one component perpendicular to the lid surface. The pulling mechanism exerts a tensile force on the brittle adhesive bond between the lid and the interior of the battery housing in a direction that, on the one hand, assists in separating the adhesive bond through the mechanical action of a cutting tool and, on the other hand, keeps the already separated sections of the lid away from the progression of the respective area of ​​mechanical stress exerted by the cutting tool, thereby improving access to this area. Such an obliquely acting tensile force could, for example, act at approximately 70° to the lid surface.

[0027] In a further embodiment, such a pulling device can include a pull rod, preferably hydraulically, pneumatically, or electrically actuated, which is fixed to the holding device via pulling elements and pulls the cover away from the cover surface, at least with one component perpendicular to the cover surface. Such a pulling device can be, for example, fixed at one end of the battery housing or adjustable along the battery's length and connected to and fixed to the holding device, for example, by cables or rods. A hydraulically or pneumatically actuated pull rod can exert high forces on the sections of the cover already separated from the adhesive, pulling the cover away from the battery housing. The pulling device can be designed so that the pulling force can be varied during the separation process and adapted to the specific separation behavior of the adhesive.

[0028] In another embodiment, it is also conceivable that the lifting device includes a winding mechanism that successively winds up the tongue-shaped, lifted edge of the lid, at least with one component of the rotation perpendicular to the lid surface, while simultaneously moving along the battery housing. This winding action exerts a similar effect on the exposed sections of the lid as the pulling mechanism, but at the same time ensures a compact and space-saving winding of the lid with synchronization of the winding axis to the progress of the lid separation.

[0029] In a further embodiment, it is conceivable that the cutting tool is guided manually and / or automatically, and that the impact or striking motion of the cutting tool is executed manually and / or automatically. For example, a worker can reposition the cutting tool within the cutting zone, identifying where further impact or striking action from the cutting tool would have the greatest effect or where the lid has not yet been sufficiently separated. Automatic guidance of the cutting tool, on the other hand, offers the advantage of fully or partially automating the cutting process, thus making it more economical. The automatic execution of the impact or striking motion, for example, using hydraulic, pneumatic, or mechanical energy, relieves the worker and is a prerequisite for automatic cutting.

[0030] It is particularly advantageous if the cutting edges of the cutting tool, especially a chisel, are designed in such a way that, under mechanical impact or shock load, the cutting tool is pressed against the inside of the cover and guided along its inner surface. Since the adhesive between the cover and the battery interior always has a certain thickness, and the cover should be removed without causing any adverse damage to the battery's interior, it is advisable to let the cutting tool slide along the usually quite thick cover, thus guiding it as far away as possible from the battery's interior. For this purpose, it is advantageous if the cutting tool or chisel has bevels with varying angles of inclination. For example, the wedge-shaped cutting area of ​​the cutting tool can be...The chisel has a wedge surface designed to rest against the battery cover with a wedge angle of essentially 0° and a wedge surface with a wedge angle greater than 0°. This causes the cutting tool or chisel to be pressed in one direction—namely, towards the cover—by sliding across the adhesive layer, thus working its way through the adhesive layer, guided, figuratively speaking, by the inner surface of the cover. Such asymmetrically shaped cutting tools or chisels can have different wedge angles depending on the adhesive material and can be adapted to different machining situations by varying the wedge angles.

[0031] Furthermore, it is advantageous if a nozzle for introducing cold into the area between the battery interior and the cover is movable together with the disconnecting tool. This eliminates the need to handle a separate nozzle in addition to the disconnecting tool.

[0032] A particularly preferred embodiment of the method according to the invention and the suitable device is shown in the drawing.

[0033] They show: Fig. 1 - a schematic representation of the structure of a device according to the invention for making the interior of closed battery housings accessible, Fig. 2 - a device according to Fig. 1 with cooling elements arranged on the battery housing, Fig. 3 - an enlarged representation of the effective zone according to Fig. 1 when accessing the inside of closed battery housings with a separation tool.

[0034] In the Fig. Figure 1 shows a schematic diagram of a device according to the invention for accessing the interior of closed battery housings 1, with which a cover 2 of the battery housing 1, which is, for example, fully bonded to the interior of the battery, can be successively detached from this interior of the battery housing 1, thus exposing the interior of the battery housing 1. Such fully bonded battery housings 1 are one, but not the exclusive, application area of ​​the present invention. However, the invention will be explained using such fully bonded batteries as an example.

[0035] The battery housing 1 has an approximately rectangular outer shape and encloses a cuboid volume in which battery cells (not shown) are arranged and bonded together. The battery housing 1 has a lid 2 that can be attached after the battery cells have been inserted and connected. The lid 2 can be bonded to the battery housing 1 and the interior of the battery, for example, using the same adhesive that bonds the battery cells together. This ensures that the entire inner surface of the lid 2 is bonded to the interior of the battery housing 1 and the battery, and cannot be easily separated.

[0036] The inventive method is used to remove the cover 2. First, the adhesive in the edge region of the battery housing 1 and between the inner surface of the cover 2 and the battery is made brittle in an edge section of the cover 2, for example, by applying cold and using separating tools 10 such as special chisels. Then, it can be separated by impacts or blows in the direction of impact 13, which can be applied via the separating tool 10. This separation of a narrow strip of the cover 2, for example, a few tens of millimeters wide, is typically carried out by hand. The battery housing 1 is fixed in the direction of load by a counter-holder 4, which is only schematically indicated, and cannot move.

[0037] The tongue-like section 16 of the cover 2, detached from the adhesive, is then brought into mechanically resilient contact with an L-shaped holding device 3. The holding device 3 serves to apply a force to the tongue-like section 16 of the cover 2, pulling the cover 2 away from the battery housing 1, at least with a vertical component. This improves the separation of the brittle adhesive, as the force exerted by the holding device 3 further opens the crack in the adhesive layer, causing the adhesive to tear open more. Furthermore, the effective area of ​​the separation tool 10 is opened during the further loosening of the bond, and the tongue-like section 16 of the cover 2 does not interfere with the further separation of the adhesive bond.

[0038] In this example, the force exerted by the holding device 3 on the cover 2 is applied by a lifting device 15 with a hydraulic or pneumatic cylinder 5, the piston rod 6 of which is connected to the holding device 3 via rods or wires 7 or 9 and a crossbar 8. When the piston rod 6 of the cylinder 5 is retracted, the crossbar 8, and thus also the holding device 3, is pulled away from the battery housing 1 and downwards in the direction of pull 17, and the tongue-like section 16 of the cover 2, which is detached from the adhesive, is pulled further away from the battery housing 1. For this purpose, the holding device 3 is bonded to the edge section of the cover 2 or mechanically connected, for example via a clamping connection or the like.

[0039] The lid 2 is gradually detached after the initial tongue-like section 16 of the lid 2 has been detached from the adhesive. This is achieved by inserting the chisel-shaped separating tool 10 into the wedge-shaped area between the inside of the battery and the inner surface of the lid 2, and thus in the direction of 13, into the area of ​​the adhesive, thereby separating the brittle adhesive. Moving the separating tool 10 laterally along the tongue-like section 16 of the lid 2, while applying the described thrusts or blows in the direction of 13, further separates the lid 2 from the adhesive in a strip. The holding device 3 and the lifting device 15 then allow the lid 2 to be pulled further downwards and away from the battery housing 1.The inner area of ​​cover 2 is thus successively separated from the adhesive from top to bottom and from left to right, until the last connection between cover 2 and battery housing 1, or the inside of the battery, is severed and cover 2 can be removed. The inside of battery housing 1 is then exposed and can be further processed for recycling battery cells or replacing individual battery cells.

[0040] The adhesive is separated under the influence of cold, which can be used to embrittle the adhesive. Firstly, the adhesive located between the inner area of ​​the cover 2 and the battery cells can be pre-cooled and kept at low temperatures, either fully or partially, by means of cooling elements 11, such as cooling pads or the like, arranged on the outside of the cover 2.

[0041] For the actual separation of the adhesive, it is important that the adhesive is subsequently exposed locally in the respective working area of ​​the separation tool 10, for example, through a nozzle 12, to a very strong cooling refrigerant 14. This refrigerant ensures that the adhesive section being processed locally by the separation tool 10 becomes brittle. Here, liquid carbon dioxide can be injected in a known manner, where it sublimates and, if necessary, is further cooled with a cold-stable liquid. It is then injected from the nozzle into the gap under the tongue-shaped section 15 of the cover 2 that has been detached from the adhesive, thus strongly cooling this area. However, it is also conceivable to direct the nozzle towards the outside of the cover 2 in this section 15 and cool the adhesive indirectly through the cover 2. A combination of both cooling methods is also possible.It is advisable to move the nozzle 12 together with or in parallel to the movement of the cutting tool 10.

[0042] The separating tool 10, designed here as a chisel, can be used as shown more clearly in the enlarged illustration in Fig.As can be seen in Figure 3, the chisel 10 is designed with unequal wedge angles. It has a first wedge surface that is either not inclined or only slightly inclined, and a second wedge surface that is more steeply inclined. If the first wedge surface, which is not inclined or only slightly inclined, is positioned opposite the inner surface of the cover 2, and the chisel 10 is actuated in the direction of impact or thrust 13, the second, more steeply inclined wedge surface slides across the adhesive and presses the chisel 10 against the inner surface of the cover 2, guiding it along this surface. This improves the separation of the adhesive from the inner surface of the cover 2, and the adhesive largely remains inside the battery, thus minimizing the risk of damage to components within the battery housing 1. Part number list 1 battery case 2 lids 3 Holding device 4 Counterholds 5 hydraulic cylinders 6 piston rod 7 bars 8 crossbar 9 bars 10 chisels 11 Cooling element 12 nozzle 13 Direction of thrust 14 Refrigerants 15 Lifting device 16 tongue-shaped section 17 Direction of travel 18th root 19 clamping brackets 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] WO 2021 / 259424 A1

[0008] DE 10 2007 052 ​​390 B4

[0009]

Claims

[1] Method for making the interior of closed battery housings (1), in particular of electric vehicles, accessible, in particular during recycling and / or repair of the battery, characterized by , that at least one edge region of a cover (2) or an outer surface of the closed battery housing (1), preferably under the influence of cold (11, 14), is mechanically separated from the rest of the battery and lifted off like a tongue, a holding device (3) is fastened to this tongue-like raised edge region (16) along the edge of the cover (2), which holding device exerts a force (17) directed away from the battery housing (1) onto the raised edge region (16) of the cover (2) via a lifting device (15), in the region of the root (18) of the tongue-like raised edge region (16), further sections of the cover (2) are mechanically detached from the battery by the supply of cold (14) and are lifted off the battery by the force of the lifting device (15) until the cover (2) is essentially completely detached from the battery and can be separated from the battery housing (1). [2] Method according to claim 1, characterized by that the holding device (3) is glued to the edge of the lid (2) in the region of the tongue-like raised edge area (16). [3] Method according to claim 1, characterized by that the holding device (3) clamps the lid (2) in the region of the tongue-like raised edge area (16). [4] Method according to claim 3, characterized by that the holding device (3) engages around the cover (2) in the region of the tongue-like raised edge area (16) and clamps it between itself. [5] Method according to one of the preceding claims, characterized by that the cover (2) is pre-cooled from outside the battery at least in partial areas (11) before being lifted off from the inside of the battery. [6] Method according to claim 5, characterized by that the lid (2) is cooled by cooling devices arranged on the outside of the lid (2), in particular cooling elements (11) or cooling pads. [7] Method according to one of the preceding claims, characterized by that cold (14) is introduced into the area between the cover (2) and the interior of the battery, which cold embrittles the adhesive between the cover (2) and the interior of the battery in a targeted manner in the areas that are separated from one another by mechanical interventions. [8] Method according to claim 7, characterized bythat the cold (14) when separating the cover (2) from the interior of the battery is introduced directly into the region of the root (18) of the tongue-like raised edge region (16), preferably directly onto the adhesive in the region of the root (18). [9] Method according to one of the preceding claims, characterized by that the cold is introduced from the side of the lid opposite the adhesive joint and the adhesive joint is thereby cooled indirectly. [10] Method according to one of the preceding claims, characterized by that the mechanical separation between the cover (2) and the interior of the battery is caused by impact or shock-loaded separating tools (10), in particular by chisels (10). [11] Method according to claim 10, characterized by that the separating tool (10) is moved manually or automatically in the area between the interior of the battery and the cover (2). [12] Method according to one of the preceding claims, characterized by that the mechanical separation between the cover (2) and the interior of the battery is effected by a shock and / or vibration load, preferably a vibration in the region of the cover, in particular in the region of the tongue-like raised edge region (16) of the cover. [13] Method according to one of the preceding claims, characterized by that a nozzle (12) for introducing the cold (14) into the area between the interior of the battery and the cover (2) is moved together with the separating tool (10). [14] Method according to one of the preceding claims, characterized by that the cold (14) is introduced with the aid of liquid carbon dioxide, preferably with the addition of a cold-stable liquid, via a nozzle (12), preferably into the area between the interior of the battery and the cover (2). [15] Device for making the interior of closed battery housings (1), in particular of electric vehicles, accessible, in particular during recycling and / or repair of the battery, in particular for carrying out the method according to claim 1, wherein at least one edge region of a cover (2) or an outer surface of the closed battery housing (1), preferably under the influence of cold (14), is mechanically separated from the rest of the battery and lifted off like a tongue, characterized byin that a holding device (3) can be fastened to the raised edge region (16) of the cover (2) along the edge-side, tongue-like raised edge, and a lifting device (15) acts on the holding device (3) and thus on the cover (2) in such a way that a force (17) directed away from the battery housing (1) acts on the raised edge region (16) of the cover (2), wherein at least one separating tool (10) engages in the region of the root (18) of the tongue-like raised edge region (16) with the supply of cold (14) and mechanically detaches further sections of the cover (2) from the battery, and the force of the lifting device (15) lifts these detached sections (16) from the battery until the cover (2) is essentially completely detached from the battery and separated from the battery housing (1). [16] Device according to claim 15, characterized bythat the holding device (3) has a preferably L-shaped angle, which is fastened with one leg to the edge region of the cover (2) which has been previously lifted off in the manner of a tongue, and with the other leg to a lifting device (15). [17] Device according to claim 16, characterized by that the holding device (3) has a clamping device on one leg which is arranged on the tongue-like raised edge region (16) of the lid (2), with which the tongue-like raised edge region (16) of the lid (2) can be clamped to the holding device (3). [18] Device according to claim 17, characterized by that the clamping device has a rod-like clamping bracket (19) which presses the tongue-like raised edge region (16) of the cover (2) against the holding device (3). [19] Device according to one of claims 15 to 18, characterized bythat the lifting device (15) has a pulling device (5, 6, 7, 8, 9) which pulls away the lifted edge region (16) of the lid (2), preferably obliquely to the lid surface, at least with a component perpendicular to the surface of the lid (2). [20] Device according to claim 19, characterized by that the pulling device (5, 6, 7, 8, 9) has a preferably hydraulically or pneumatically or electrically actuated pull rod (6) which is fixed to the holding device (3) via pulling elements (7, 8, 9) and pulls the cover (2) away with at least one component perpendicular to the surface of the cover (2). [21] Device according to one of claims 15 to 18, characterized bythat the lifting device (15) has a winding device which successively winds up the tongue-like lifted edge region (16) of the cover (2) with at least one component of the direction of rotation perpendicular to the surface of the cover (2) and in the process moves along the battery housing (1). [22] Device according to one of claims 15 to 21, characterized by that the cutting tool (10) is guided manually and / or automatically and the impact or striking movement of the cutting tool (10) is carried out manually and / or automatically. [23] Device according to one of claims 15 to 22, characterized by that the cutting edges of the separating tool (10), in particular a chisel (10), are designed such that the separating tool (10) is pressed against the interior of the lid (2) and guided along the interior of the lid (2) when subjected to mechanical stress. [24] Device according to claim 23, characterized bythat the chisel (10) has bevels with different bevel angles. [25] Device according to claim 24, characterized by that the wedge-shaped cutting area of ​​the chisel (10) has a wedge surface intended for contact with the cover (2) of the battery with a wedge angle of substantially 0° and a wedge surface with a wedge angle of more than 0°. [26] Device according to one of claims 15 to 25, characterized by that a nozzle (12) for introducing the cold (14) into the area between the interior of the battery and the cover (2) is arranged to be movable together with the separating tool (10).

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