Battery cell having electrode conductor insulation

Abstract

To provide a battery cell in which the conductor tracks of individual electrode layers are insulated against a casing in a manner which is particularly easy to achieve, and a method for manufacturing the same.SOLUTION: A battery cell (1) has a layer stack (2) including a plurality of anode layers (An) and a plurality of corresponding cathode layers (K), the anode layers (An) and the cathode layers (K) being stacked alternately one on top of the other. Anode conductor tracks (4a) or cathode conductor tracks (4K) are combined in a bundled manner and each are contact-connected to a current collector. Insulation layers (IL) each project over the layer stack (2) at their free second ends (E2), the free second ends being oriented with respect to face each other while forming folded portions (24) extending toward each other. The insulation layers (IL) are held in position by a spring effect of their folded portions (24) against a pressure that is applied indirectly by a first cover (8).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a battery cell comprising a layer stack having a plurality of anode layers and a plurality of corresponding cathode layers stacked one on top of the other, with a separator layer disposed therebetween, and a casing having a cover that surrounds the layer stack with anode conductor tracks or cathode conductor tracks guided laterally from the layer stack and that has an inner anode current collector or an inner cathode current collector on one end face of the layer stack.

[0002] Today, battery cells are typically available in three different configurations. Prismatic cells have a rigid frame or casing in which the individual anode, cathode, and separator layers are arranged. Each of these layers is connected to a corresponding anode or cathode terminal housed in the casing via conductor tracks leading from the stack of layers. In cylindrical cells, the stack of anode and cathode layers is wound alternately, with the electrical contacts for the anode and cathode layers made along the cylinder axis or on the exterior of the cylinder. In so-called pouch cells, the anode and cathode layers are stacked flat on top of each other, and a flexible film, from which only the two conductor tracks of the anode or cathode protrude, seals the cells for environmental protection.

[0003] In prismatic battery cells, a rigid casing not only provides mechanical stability to the cell, but also allows for the use of stable electrical terminals, and further allows for good thermal coupling to the surroundings and therefore better heat dissipation, which has an advantageous effect on the life of the cell.

[0004] In this case, however, the individual conductor tracks that are guided in a bundle from the layer stack to the respective anode or cathode current collector and contacted there must be electrically insulated from the housing. If necessary, the bundle here also forms a loop inside the housing between the layer stack and the current collector, which loop should preferably also be insulated.

[0005] The application of such insulation is difficult to achieve from a manufacturing technology perspective, since the conductor tracks are often formed from uncoated copper or aluminum substrate sheets of the associated electrode layers and therefore only have a thickness of 4 μm to 15 μm in some cases. This can lead to the conductor tracks easily wrinkling or tearing. Furthermore, a solution is required to guide the conductor tracks, which makes it possible to dispense with separate insulation. Furthermore, fixing the insulation is not easy in this context.

[0006] The present invention is therefore based on the object of providing a battery cell in which the conductor tracks of the individual electrode layers are insulated from the housing in a particularly easily achievable manner, and also on the object of providing a method for manufacturing such a battery cell.

[0007] The first-mentioned problem is solved by the present invention by a battery cell, in particular a prismatic battery cell, which comprises a layer stack having a plurality of anode layers and a corresponding plurality of cathode layers, the anode layers and cathode layers being stacked one on top of the other, with a separator layer disposed between each anode layer and each cathode layer, and at least on a first end face of the layer stack consisting of at least some of the anode layers and / or some of the cathode layers, anode conductor tracks or cathode conductor tracks being guided laterally out of the layer stack, the battery cell further comprising a casing which encloses the layer stack together with the anode conductor tracks or cathode conductor tracks and has a first cover which has an inner anode current collector or an inner cathode current collector at least on the first end face of the layer stack, in which the anode conductor tracks or cathode conductor tracks, respectively, are gathered in a bundle and are contact-connected to the anode current collector or cathode current collector, respectively. The battery cell further comprises at least two insulating layers, each fixed at a first end to the upper or lower surface of the layer stack, and each protruding at its second free end from the layer stack, the second ends oriented toward each other forming mutually extending folds, whereby a bundle of anode conductor tracks or a bundle of cathode conductor tracks, respectively, is pulled between the two folds, and the insulating layers are held in place by the spring action of the respective folds of the insulating layers against the pressure indirectly applied by the first cover. The object of the present invention, which is advantageous in itself, is the subject of the respective dependent claims and the following description.

[0008] The second problem is solved according to the invention by a method for producing a battery cell, in which a plurality of anode and corresponding cathode layers are alternately stacked to form a layer stack, with a respective separator layer arranged between each anode layer and each cathode layer, and the respective anode or cathode conductor paths of at least some of the anode and cathode layers are guided laterally out of the layer stack, gathered into bundles, and contact-connected to the anode or cathode current collectors of a or each cover for the battery cell casing.

[0009] In this case, the method involves fixing at least one insulating layer to the upper or lower surface of the layer stack so that the layer stack protrudes from the insulating layer, guiding the free end of the insulating layer from above or below towards the bundle of anode conductor tracks or the bundle of cathode conductor tracks, respectively, while forming a fold, and pressing the or each cover towards the layer stack, so that pressure is applied to the free end of the insulating layer beyond the respective fold, and the layer stack together with the pressed cover is fixed, and enclosed in a casing during or after the fixing.

[0010] The method for manufacturing a battery cell according to the invention shares its advantages with the battery cell according to the invention: the advantages indicated for the battery cell and its developments can be significantly applied to the method, mutatis mutandis, and vice versa.

[0011] The battery cell is preferably a lithium (Li)-ion battery cell. The anode and cathode layers (hereinafter also referred to collectively as electrode layers) are preferably obtained by coating a substrate, particularly a sheet, with an active material. A copper substrate sheet is preferably used for the anode layer, and a coating preferably consisting of graphite, silicon (Si), or silicon oxide (SiOx) is deposited on the substrate as the active material. An aluminum substrate sheet is preferably used for producing the cathode layer K, and a coating preferably consisting of lithium iron phosphate (LFP) or one or more lithium-nickel-manganese-cobalt oxides (Li-NMC) is deposited on the substrate as the active material. The separator layers can be obtained, in particular, by ceramic-coated plastic sheets.

[0012] The alternating arrangement of anode layers and cathode layers (and the separator layers respectively arranged therebetween) in the layer stack is understood in this case to mean, in particular, that the layer stack is composed of a plurality (preferably a large number) of element cells, each having one anode layer, one separator layer, and one cathode layer. In particular, in this case, it is also possible to coat both sides of the substrate sheet for the anode and cathode layers with the corresponding active material, so that in this case the alternating rows of anode and cathode layers on each substrate sheet are mirror-symmetrical (i.e., for example, an anode layer-separator layer-cathode layer row as an element cell is first followed by an aluminum substrate sheet for the cathode layer, which is then followed accordingly by an element cell of a cathode layer-separator layer-anode layer row with the corresponding subsequent copper substrate sheet, with the layer stack being formed by the periodic repetition of such rows).

[0013] At the first end face of the layer stack, anode conductor tracks are led out from at least some, preferably all, of the anode layers and gathered into a bundle. The anode conductor tracks can be formed directly from an uncoated substrate (i.e., a copper substrate sheet), in particular. The same applies to the cathode conductor tracks, preferably from an aluminum substrate sheet. The anode conductor track bundles and cathode conductor track bundles, which are guided alongside the same (first) end face of the layer stack (or alongside the opposite edges of the end face) or out from two opposing end faces (first and second end faces), are electrically connected to corresponding anode or cathode current collectors, which are arranged on the inner surface of one or both covers (first and second covers) for the battery cell casing. In this case, the contact connection can be effected by a welding process, particularly in the manufacturing method, and in particular the cover can for this purpose be tilted or pivoted by 90° relative to its set position in the finished housing, and can only be brought into its original position by pressing.

[0014] In particular, if the anode and cathode conductor tracks are guided out of the layer stack at the respective opposite end faces (first end face or second end face), only the anode or cathode conductor tracks can be routed out in the manner described above through two insulating layers fixed to the top or bottom face of the layer stack at the relevant end face, while the respective other conductor tracks at the other end face can be insulated from the housing (i.e., in particular without the above-mentioned fold of the second insulating layer).However, in an alternative configuration, the anode and cathode conductor tracks can be guided out of the layer stack at the respective opposite end faces (first end face or second end face), two insulating layers can be fixed to the top or bottom face in the region of the two end faces, respectively, and the cathode and anode conductor tracks on the corresponding face can be guided to the corresponding current collector in the first or second cover through a fold of the insulating layer formed thereon, respectively.

[0015] In this case, an anode terminal and / or a cathode terminal is disposed on the outer surface of the first cover, and this anode terminal and / or cathode terminal is electrically contact-connected to the corresponding anode current collector or cathode current collector through the first cover, thereby allowing the battery output of the battery cell to be taken out to the outside via the corresponding terminal.

[0016] At the top and bottom surfaces of the layer stack, defined by the layer start and layer end of the electrode layer, respectively, an insulating layer is fixed such that its first end is fixed to the top or bottom surface of the layer stack and its second free end protrudes from the layer stack, preferably at the end surface. The free ends of the insulating layers initially follow the extension direction of the bundle of anode conductor tracks or the bundle of cathode conductor tracks. The insulating layers are guided around the tapered bundles and form a fold at their free ends (second ends). This means, in particular, that the free ends (second ends) of the insulating layers fixed at the top surface of the layer stack (at the first ends) are initially oriented toward the central plane of the layer stack (in the stacking direction), and the anode conductor tracks are guided between the end surface of the layer stack and the insulating layer, preferably in the region of the central plane, so that the free ends are again oriented away from the central plane. A similar configuration (but with the upper and lower relationships symmetrically swapped) forms an insulating layer fixed to the lower surface of the layer stack.

[0017] Thus, two folds are present in the two insulating layers, particularly in the region of the central plane, and are oriented opposite to one another. These two folds guide the anode and cathode conductor bundles. When the first cover of the completed battery cell is pressed against the end face of the layer stack, the insulating layer, due to the respective folds and the spring action that occurs at least indirectly due to the pressure of the cover (e.g., on the first cover itself or on the anode or cathode conductors in the region of the first cover), does not pull back or slide back from this position, but remains in place, particularly with the folds near the bundles. This allows the anode or cathode conductors to be insulated from the casing in the region of the end face of the layer stack or the region of the end face of the first cover. For this purpose, the insulating layer is preferably made of an insulating material with appropriate strength.

[0018] In this case, the manufacturing method preferably includes injecting or otherwise adding electrolyte into the battery cell (e.g., through an injection opening in the first cover provided for this purpose, which is subsequently closed) before the casing is finally closed. In particular, in this case, the manufacturing method also allows the contact connection of the anode or cathode conductor tracks on the corresponding current collectors of the first cover to take place both after the insulating layer has been applied to the layer stack and after the respective fold has been formed.

[0019] In one preferred configuration, the casing has a first cover at a first end face of the layer stack, which has an inner anode current collector with contact connection to the anode conductor path routed between the folds of the two insulating layers. The casing also has a second cover at a second end face opposite the first end face of the layer stack, which has an inner cathode current collector guided laterally from the layer stack at the second end face and with contact connection to the cathode conductor path routed between the folds of the other two insulating layers. This means, in particular, that the anode terminal and the cathode terminal of the battery cell each have two opposite end faces. The contact connection of the terminals, and thus the contact connection of the corresponding current collector with the corresponding anode conductor path or cathode conductor path of each anode layer or cathode layer, is achieved by the aforementioned route-out through two mutually aligned folds of each of the two insulating layers.

[0020] This means that at the first end face of the layer stack, the anode conductor tracks are guided to the anode current collector through two insulating layers fixed thereto (and folds formed therein by the pressure of the first cover), while at the second end face of the layer stack, the cathode conductor tracks are guided to the cathode current collector through two insulating layers fixed thereto (and folds formed therein by the pressure of the second cover).

[0021] Preferably, when manufacturing such a battery cell, first the anode conductor paths guided out from the layer stack are gathered into a bundle at the first end face so that they can be contacted with the corresponding anode current collector of the first cover, the first cover is pressed onto the layer stack, thereby applying pressure, in particular, to the two folds formed in the two corresponding insulating layers, and fixing the layer stack together with the pressed-on cover, and then (preferably after the composite consisting of the layer stack and the anode-side cover has been introduced into the casing) the cathode conductor paths guided out from the layer stack at the second end face opposite the first end face are gathered into a bundle so that they can be contacted with the cathode current collector, which cathode current collector is arranged in a second cover for the casing, and the second cover is pressed onto the layer stack, thereby applying pressure across the respective folds to the free ends of the corresponding insulating layers, and the layer stack together with the fixed first cover and the pressed-on second cover is enclosed in the casing. In this case, the first cover can be fixed in the layer stack by means of, for example, a protective film, a protective cover, or the like.

[0022] In particular, the sequence is such that first the cathode conductor path can be contact-connected to the cathode current collector in the corresponding cover, then this cover (with the cathode conductor path brought out between the folds of the insulating layer while pressure is applied to the free end of the corresponding insulating layer) is pressed against the layer stack and can be fixed thereto, after which the anode conductor path can be contact-connected to the anode current collector in the corresponding other cover, then this cover (with the anode conductor path brought out between the folds of the insulating layer while pressure is applied to the free end of the corresponding insulating layer) is pressed against the layer stack and can be fixed thereto or can be enclosed in a casing.

[0023] In an equally advantageous alternative configuration, the anode and cathode conductors at a first end face of the layer stack are guided laterally from the layer stack, offset parallel to each other in the direction of extension of the anode and cathode layers, and the first cover has anode and cathode current collectors, where the anode and cathode conductors are contacted by being routed through folds in the two insulating layers. Thus, in this configuration, two terminals for removing battery power to the outside, i.e., the anode and cathode terminals, are arranged on the same end face of the first cover. Correspondingly, the anode and cathode conductors are routed from the layer stack at the same end face, and insulating layers are fastened to the top and bottom of this end face, respectively, through folds in the insulating layers through which the anode and cathode conductors are routed to their corresponding current collectors.

[0024] Preferably, in the battery cell, the bundle of anode conductor tracks and / or the bundle of cathode conductor tracks form at least one loop between the layer stack and the first cover or the second cover, with at least one of the two insulating layers being guided at its fold in the loop. This particularly means that, when the layer stack is viewed from the side (relative to the stacking direction), the bundle is preferably bent into a simple U-shape or a double U-shape (particularly completely across the aforementioned central plane of the layer stack). The loop is formed in this case in particular so that the anode conductor tracks or the cathode conductor tracks have a certain excess length when or for contacting the corresponding current collector in the cover, so that the U-shaped turn is formed (or occurs) when the first cover (or the second cover) is pressed against the layer stack. In this case, at least one of the two insulating layers is preferably guided into the U-shaped turn so that the associated fold is positioned in the inner vertex region of the U-shaped turn.

[0025] For this purpose, in the manufacturing method, at least one of the insulating layers, preferably both insulating layers on the same side, is guided from above or below toward the bundle through a corresponding downholder, with the associated downholder (or both downholders) being removed during or after pressing in the corresponding cover. The downholder thus converges the respective insulating layers into a bundle and also converges the insulating layers around the bundle toward the midplane of the layer stack, whereby folds of the insulating layers can also be formed by the pressure applied by the downholder (e.g., from above) to the insulating layers and by counter pressure applied across the downholder (e.g., from below) through the bundle of anode conductor tracks or the bundle of cathode conductor tracks. Due to the pressure applied by the corresponding cover or the pressure transmitted through the bundle to the insulating layers, in particular to the folds of the insulating layers, the respective folds remain in their position, in particular in the region of the inner apex of the U-shaped turn of the aforementioned loop, even after the downholder is removed.

[0026] Advantageously, at least one additional insulating layer is applied to the region of the anode current collector on the bundle formed by the anode conductor tracks and / or to the region of the cathode current collector on the bundle formed by the cathode conductor tracks.

[0027] Advantageously, each insulating layer is made from a polyolefin, such as polypropylene (PP) or polyethylene (PE), and / or polyimide, which insulating materials have particularly advantageous properties regarding the formability of the folds.

[0028] The layer stack is preferably packaged at least on its upper and lower surfaces in a protective film to which an insulating layer is attached at each first end. In this case, the protective film prevents the layer stack with any active material from contacting the casing in the completed battery cell, thereby also serving as electrical insulation. The protective film can be made of PP, in particular. Alternatively or additionally, the layer stack can be terminated on its upper and lower surfaces with a separator layer, respectively.

[0029] Advantageously, the insulating layers are each glued at their first end for fastening to the layer stack, in particular by means of an adhesive strip, preferably a self-adhesive strip, which preferably covers only the area where the associated insulating layer is fastened to the layer stack, in particular the area protruding from the layer stack being cut out.

[0030] Advantageously, the insulating layer can be fixed above or below the layer stack in a hot pressing step. Such a hot pressing step ("hot press") is frequently used in the production of battery cells to compactly join the individual electrode layers and separator layers of the layer stack. In the framework of such a hot pressing step, the insulating layer can also be fixed to the layer stack. In this case, in particular, the above-mentioned adhesive strip can be omitted.

[0031] In the following, an embodiment of the invention will be explained in more detail with reference to the drawings, in which: [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a series of cross-sectional views illustrating a method of manufacturing a battery cell with electrode conductor insulators.

[0033] 1 shows a schematic diagram of a method for manufacturing a battery cell 1 along with a series of cross-sectional views of said battery cell 1 during manufacture, which in this case is obtained by a Li-ion battery cell.

[0034] In a first method step S1, a plurality of anode layers An and a corresponding plurality of cathode layers K are provided as electrode layers. The anode layers An and cathode layers K are alternately stacked together with separator layers S, such that there is always one separator layer S between one anode layer An and one cathode layer K, to form a layer stack 2.

[0035] The anode layer An can be produced, for example, by depositing a layer of graphite or Si or SiOx on a copper substrate sheet, where the coating forms the active material of the anode layer An during operation of the completed battery cell 1. For the production of the cathode layer K, a coating of LFP or Li-NMC is preferably provided on an aluminum substrate sheet, which coating forms the active material of the cathode layer K during operation of the completed battery cell 1. Each coating can be deposited, in particular for the anode layer An or for the cathode layer K, on ​​both sides of the corresponding substrate sheet.

[0036] The separator layers S can be, in particular, each formed by a ceramic-coated plastic sheet. The separator layers S are arranged between the anode layer An and the cathode layer K, respectively, during the formation of the layer stack 2. Here, the layer stack 2, which has a substantially rectangular parallelepiped geometry, is preferably closed at its upper and lower faces Fo and Fu by the separator layers S, respectively. Alternatively or additionally, the layer stack 2 can be further covered at least at its upper and lower faces Fo and Fu with a protective film (not shown), which can be made of, for example, PP. Closing the layer stack S at its upper and lower faces Fo and Fu with the separator layers S or protective film prevents the active material of any of the electrode layers An and K of the layer stack 2 from coming into contact with the casing of the completed battery cell 1. The layer stack 2 can also be hot-pressed to more compactly bond the separator layers S and the adjacent anode and cathode layers K. In this case, the hot-pressing is preferably carried out at a temperature of 60°C to 90°C, particularly preferably 70°C to 80°C.

[0037] In the embodiment shown in FIG. 1, individual anode conductors 4a of the anode layer An and individual cathode conductors 4k of the cathode layer K are led out of the layer stack 2 at the end face F1. The anode conductors 4a and the cathode conductors 4k are laterally offset from each other relative to the image plane, i.e., the anode conductors 4a are led out laterally from the layer stack further forward (or further rearward) relative to the image plane than the cathode conductors 4k. In this case, the anode conductors 4a or the cathode conductors 4k can each be formed directly from an uncoated substrate (i.e., the anode layer from a copper substrate sheet or the cathode layer from an aluminum substrate sheet). In a second method step S2, the anode conductors 4a of the anode layer An are gathered into a bundle 6a. This bundle 6a of anode conductors 4a is electrically contact-connected to the first cover 8 of the casing of the completed battery cell 1. For this purpose, an anode current collector 12a is disposed on the inner surface 10 (relative to the later positioning of the first cover 8 in the completed battery cell 1), and this anode current collector 12a is electrically connected through the first cover 8 to an anode terminal 16a disposed on the outer surface 14 of the first cover 8. The anode terminal 16a can be externally (electrically) connected for later use of the completed battery cell 1 in a battery system.

[0038] For the above-mentioned contact connection of the anode conductor track 4a on the anode current collector 12a, the first cover 8 is initially tilted by 90° relative to its position in the later completed battery cell 1, so that the anode current collector 12a can be accessed from a direction 18 perpendicular to the end face F1 (and from a direction 18 parallel to the stacking direction in the layer stack 2) for the above-mentioned welding of the anode conductor track 4a.

[0039] 1 , the same applies to the cathode conductor tracks 4k of the cathode layer K, which are not specifically shown because they are located at the rear in the image plane. The cathode conductor tracks 4k are also bundled and electrically contacted at corresponding cathode current collectors on the inner surface 10 of the first cover 8, which are electrically connected to corresponding cathode terminals (for connecting the completed battery cells 1 in the battery system) on the outer surface 14 of the first cover. The described contact connections can also be made before the layer stack 2 is hot-pressed, if necessary.

[0040] In a third method step S3, an insulating layer IL is applied to the upper surface Fo or the lower surface Fu of the layer stack 2, respectively. The insulating layer IL is preferably made of a polyolefin, such as PP or PE, or a polyimide. In this case, the insulating layer IL is fixed at its first end E1 to the corresponding upper surface Fo or lower surface Fu of the layer stack 2 (to the separator layer S or protective film). For this purpose, the first end E1 of the insulating layer IL can be provided with a self-adhesive layer G1. Alternatively or additionally, the respective insulating layer IL can be fixed to the upper surface Fo or lower surface Fu of the layer stack, i.e., preferably to the separator layer S or the plastic sheet of the polymer protective film, only in the above-mentioned hot-pressing substep (for this purpose, only performed in method step S3). The insulating layer IL has a second free end E2 that protrudes from the layer stack 2 and is guided along the anode conductor track 4a or the cathode conductor track 4k, respectively.

[0041] In a fourth method step S4, the second free end E2 of the insulating layer IL is guided by down-holders 20 introduced laterally into the layer stack 2 in direction 18 or opposite direction 18 into the bundle 6a of anode conductor tracks 4a or the corresponding bundle of cathode conductor tracks 4k. The bundle 6a (the same applies to the bundle of cathode conductor tracks 4k, not visible in FIG. 1 ) forms loops 22 with slight double turns and into which the insulating layer IL is pushed from above or below through the respective down-holders 20, so that the second end E2 of the insulating layer IL forms a respective fold 24 within the loop 22. In this case, the down-holders 20 can be introduced slightly offset from one another, so that the insulating layer IL of the loop 22 formed in the bundle 6a can be easily adapted from above or below, respectively.

[0042] In a fifth method step S5, the first cover 8 is tilted 90° in the set position, and the layer stack is enclosed in the casing 26. For this, the downholders 20 are again removed from the loops 22 of the bundles 6a of the anode conductor tracks 4a (or the corresponding bundles of the cathode conductor tracks 4k), so that the first cover can be fixed (for example, by welding) on ​​the casing 26. Before the first cover 8 is fixed in this way, electrolyte can also be injected into the casing 26, but this injection can also take place after the first cover 8 has been fixed through corresponding injection openings in the first cover 8 that are subsequently closed. In this way, after final closure, the battery cell 1 is completed.

[0043] Even when the downholder 20 is removed, the insulating layer IL remains in place within the loop 22 due to pressure applied indirectly from the first cover via the loop 22 by the bent anode or cathode conductor track through the fold 24 of the second free end E2. What is important here is only the position of the first cover 8, which is tilted and displaced toward the end face F1. The fold 24 prevents the second free end E2 of the insulating layer IL from pulling back or sliding back, making the loop 22 sufficiently tight.

[0044] In an alternative variant, only the anode conductor 4a is guided at the first end face F1 of the layer stack, while the cathode conductor 4k is guided out of the layer stack 2 at a second end face (not shown) opposite the first end face F1. The anode conductor 4a is fixed by drawing it out between the insulating layer IL at the anode current collector 12a of the first cover 8, as explained in connection with steps S2 to S4. The first cover 8 is then pressed onto the layer stack 2 and fixed there (e.g., by means of its protective film). Steps S2 to S4 are then repeated to fix the cathode conductor 4 to the corresponding cathode current collector of the second cover (not shown), with the cathode conductor 4k being drawn out between folds made in the insulating layer (not shown) fixed to the layer stack 2 in the region of the second end face. Finally, the second cover is pressed onto the layer stack 2, which is then enclosed in a casing.

[0045] Although the details of the present invention have been illustrated and described in detail by preferred embodiments, the present invention is not limited to the disclosed examples, and those skilled in the art can derive other variations from these examples without departing from the scope of protection of the present invention. [Explanation of symbols]

[0046] 1 battery cell Two-layer stack 4a / 4k anode conductor / cathode conductor 6a (Anode conductor) bundle 8 Cover 10 (Cover) Inner Surface 12a Anode current collector 14 Outer surface of cover 16a Anode terminal 18 (perpendicular to the end face) direction 20 Down Holder 22 Loop 24 Folding section 26 Casing An anode layer E1 / E2 (insulating layer) first end / second end F1 (layer stack) end face Fo / Fu Top / Bottom (of layer stack) G1 self-adhesive layer K cathode layer IL insulating layer S separator layer S1~S5 method steps

Claims

1. A battery cell (1), a layer stack (2) comprising a plurality of anode layers (An) and a corresponding plurality of cathode layers (K), the anode layers (An) and the cathode layers (K) are stacked alternately, and one separator layer (S) is disposed between each anode layer (An) and each cathode layer (K); - at least at a first end face (F1) of the layer stack (2) consisting of at least some of the anode layers (An) and / or some of the cathode layers (K), anode conductor tracks (4a) or cathode conductor tracks (4k) are guided laterally out of the layer stack (2), a layer stack (2); a casing (26) which encloses the layer stack (2) together with the anode conductor tracks (4a) or the cathode conductor tracks (4k) and has a first cover (8) which has an inner anode current collector (12a) or an inner cathode current collector at least on the first end face (F1) of the layer stack (2), the anode conductor tracks (4a) or the cathode conductor tracks (4k) are respectively bundled together and are respectively contact-connected to the anode current collector (12a) or the cathode current collector; a casing (26); - at least two insulating layers (IL) fixed at their first ends (E1) to the upper face (Fo) or the lower face (Fu) of said layer stack (2), respectively; Including, the at least two insulating layers (IL) each project at their second free ends (E2) from the layer stack (2), the second ends (E2) being oriented towards one another while forming mutually extending folds (24), so that the bundles (6a) of anode conductor tracks (4a) or the bundles of cathode conductor tracks, respectively, are brought out between the two folds (24); - the at least two insulating layers (IL) are held in place by the spring action of the folds (24) of each of the at least two insulating layers (IL) against the pressure indirectly applied by the first cover (8); Battery cell (1).

2. The casing (26) - a first cover on the first end face (F1) of the layer stack (2) with the inner anode current collector (12a) to which the anode conductor track (4a) is contacted, which is brought out between the folds (24) of the two insulating layers (IL), a second cover on a second end face of the layer stack (2) opposite to the first end face (F1), the second cover having the inner cathode current collector (12k) guided laterally from the layer stack (2) at the second end face and contacted by a cathode conductor track (4k) brought out between two further folds of the insulating layer (IL), The battery cell (1) according to claim 1.

3. the anode conductor tracks (4a) and the cathode conductor tracks (4k) at the first end face (F1) of the layer stack (2) are guided laterally from the layer stack (2) in a manner offset parallel to one another with respect to the extension direction of the anode layers or the cathode layers, the first cover (8) has the anode current collector (12a) and the cathode current collector, and the anode conductor tracks (4a) and the cathode conductor tracks (4k) are respectively brought out through the folded portions (24) of the two insulating layers (IL) to be in contact with the anode current collector (12a) and the cathode current collector. The battery cell (1) according to claim 1.

4. the bundle (6a) of anode conductor tracks (4a) and / or the bundle (4k) of cathode conductor tracks (4k) form at least one loop (22) between the layer stack (2) and the first cover (8), At least one of the two insulating layers (IL) is guided at its folded portion (24) within the loop (22). A battery cell (1) according to claim 1 or 2.

5. 5. The battery cell (1) according to claim 4, wherein at least one additional insulating layer is applied to the region of the anode current collector (12a) on the bundle (6a) formed by the anode conductor tracks (4a) and / or to the region of the cathode current collector on the bundle (6a) formed by the cathode conductor tracks (4k).

6. The battery cell (1) according to claim 1 or 2, wherein the at least two insulating layers (IL) are each made of polyolefin and / or polyimide.

7. A method for manufacturing a battery cell (1), comprising the steps of: - a plurality of anode layers (An) and a corresponding plurality of cathode layers (K) are alternately stacked to form a layer stack (2), with one separator layer (S) respectively arranged between each anode layer (An) and each cathode layer (K), - for at least some of the anode layers (An) and some of the cathode layers (K), the anode conductor tracks (4a) or cathode conductor tracks (4k), respectively, are guided laterally out of the layer stack (2) and gathered into a bundle and are then contact-connected to the anode current collector (12a) or cathode current collector of the or each cover (8) for the casing (26) of the battery cell (1); - fixing at least one insulating layer (IL) to the upper face (Fo) or the lower face (Fu) of said layer stack (2) respectively, in such a way that said layer stack (2) protrudes from said insulating layer (IL), - guiding the free end (E2) of the insulating layer (IL) from above or below towards the bundle (6a) of anode conductor tracks (4a) or towards the bundle of cathode conductor tracks (4k), respectively, while forming a fold (24), - pressing the or each cover (8) towards the layer stack (2), thereby applying pressure to the free end (E2) of the insulating layer (IL) beyond each of the folds (24); - said layer stack (2) is fixed together with said pressed cover (8) and enclosed in said casing (26) during or after said fixing, method.

8. - firstly, the anode conductor tracks (4a) or the cathode conductor tracks (4k) guided out of the layer stack (2) at the first end face (F1) are gathered into a bundle and contact-connected to the corresponding anode current collectors (12a) or cathode current collectors of the first cover (8) for the casing (26); - pressing the first cover (8) towards the layer stack (2) and fixing the layer stack (2) by the pressed cover (8), - subsequently converging the respective further conductor paths of the anode conductor path (4a) or the cathode conductor path (4k) guided from a second end face of the layer stack (2) opposite the first end face (F1) into a bundle and contact-connecting them to the corresponding respective further current collector of the anode current collector (12a) or the cathode current collector, which is arranged in a second cover for the casing (26); - pressing the second cover towards the layer stack (2), thereby applying pressure to the free end of the corresponding insulating layer across each fold; - Enclosing the layer stack in the casing (26) with the first cover (8) fixed and the second cover pressed on, The method of claim 7.

9. At least one of the insulating layers (IL) is guided towards the bundle (6a) from above or below through a downholder (20), The associated downholder (20) is removed during or after pressing of the corresponding cover (20), 9. The method according to claim 7 or 8.

10. The method according to claim 7 or 8, wherein the insulating layer (IL) is fixed above or below the layer stack (2) in a hot pressing step.

11. 9. Method according to claim 7 or 8, characterized in that the insulating layer (IL) is fixed to the upper (Fo) or lower (Fu) face of the layer stack (2) by means of adhesive strips (G1), respectively.

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