Electrode assembly for a battery cell, method for producing an electrode assembly for a battery cell, and battery cell having an electrode assembly of this type

Abstract

The invention relates to an electrode assembly for a battery cell, comprising a plurality of first electrodes (1) and a plurality of second electrodes (2) which, in the electrode assembly, are alternately stacked one on top of the other in a stacking direction (s) or wound into an electrode roll (R) and alternately follow one another in a radial direction (r), wherein the first electrodes (1) and the second electrodes (2) each have an electrically conductive carrier layer (3) and a coating (4) made of an active material on at least one side of the carrier layer (3), and an edge section of each carrier layer (3) is designed as a contact section (5) which is at least partially free of the coating (4). In order to make extensive contact between the first electrodes (1) and between the second electrodes (2), a respective electrically conductive material (6-1; 6-2) is introduced between the contact sections (5-1) of adjacent first electrodes (1) and between the contact sections (5-2) of adjacent second electrodes (2) in order to electrically conductively connect the contact sections (5-1) of the first electrodes (1) to one another and the contact sections (5-2) of the second electrodes (2) to one another. This allows for extensive contact between the electrodes (1, 2) while avoiding excessively high current densities at the contact point. The invention further relates to a method for producing an electrode assembly for a battery cell and to a battery cell having an electrode assembly of this type.

Description

[0001] Electrode arrangement for a battery cell, method for manufacturing an electrode arrangement for a battery cell and battery cell with such an electrode arrangement

[0002] The invention relates to an electrode arrangement, e.g. in the form of an electrode stack or an electrode roll, for a battery cell, in particular for a lithium-ion battery cell, a method for manufacturing an electrode arrangement for a battery cell and a battery cell with such an electrode arrangement.

[0003] A battery cell, such as a lithium-ion battery cell, stores energy in the form of an electrochemical reaction in which cations, for example lithium ions, move between a positive and a negative electrode. The two electrodes are referred to as the anode (negative terminal) and the cathode (positive terminal) according to their respective functions during cell discharge. The electrodes are protected from direct contact by a separator that is permeable to the cations (e.g., the lithium ions).

[0004] Since the electrode materials lack sufficient mechanical strength, they are each applied to a metal foil, the so-called collector foil, which serves for current conduction and contact. Typically, a copper foil is used for the anode and an aluminum foil for the cathode.

[0005] To manufacture a battery cell, the collector foils coated with electrode materials are rolled together with the separators into an electrode roll ("jelly roll"), folded in a Z-shape ("Z-folding"), or stacked into an electrode stack. This creates an electrode assembly (electrode pack) that maximizes the surface area of ​​the electrode and separator layers. The electrode assembly can then be compactly housed in a cell casing. To conduct current (during discharge) or supply it (during charging), an electrical contact must be established with the collector foils, allowing an electric current to be conducted to the contact points located on the outside of the cell casing.

[0006] The following methods for contacting the electrodes of a battery cell are known from the prior art: a) The collector foil has an extension ("tab") at one or more points, which is connected to other components, e.g., the outer contact surfaces of the battery, during the subsequent assembly process of the battery cell. In this contacting method, the entire current flowing through the cell during the charging or discharging process flows through this extension(s), resulting in a concentration or maximum current density at this point. The extensions can be part of the collector foil itself or separately applied components. b) An uncoated portion of the metal foil protrudes over the edge of the rolled, folded, or stacked electrode assembly at one edge, extending across the entire width of the electrode.For contacting, the protruding edges of the electrode are bent over and welded to a contact plate, which is connected to other components, e.g. the outer contact surfaces of the battery, in the later assembly process of the battery cell ("tabless design").

[0007] From DE 10 2022 103 728 B3, a battery cell is known comprising a housing, an electrode stack arrangement, at least one clamping arrangement and at least two counter elements associated with the clamping arrangement, wherein the electrode stack arrangement is arranged in the housing and comprises first electrode arrangements and second electrode arrangements, wherein the first electrode arrangements comprise first electrodes and first strip elements and the second electrode arrangements comprise second electrodes and second strip elements, and the at least one clamping arrangement comprises a base part, two clamping elements and at least two arms, each extending between the base part and one of the clamping elements and configured to apply a first force to the clamping elements in the direction of the associated counter elements.In this arrangement, first strip elements or second strip elements are arranged between at least one of the clamping elements and at least one of the counter elements, and the base part forms an externally contactable connection element for electrical contacting the battery cell and is electrically connected to the first electrodes via the first strip elements or to the second electrodes via the second strip elements.

[0008] Against this background, the object of the invention is to provide an electrode arrangement, in particular in the form of an electrode stack or an electrode roll for a battery cell, which enables large-area contacting of the electrodes while avoiding excessively high current densities at the contact point. A further object is to provide a battery cell with an electrode arrangement, wherein the number of steps required for contacting the electrodes of the electrode arrangement during the manufacture of the battery cell and / or the complexity of the contacting of the battery cell are to be minimized.

[0009] The invention solves these problems through the electrode arrangement with the features of claim 1, with the method for manufacturing an electrode arrangement with the features of claim 18, and with a battery cell according to claim 34.

[0010] The electrode arrangement according to the invention for a battery cell is in the form of an electrode stack or an electrode roll and can be used in particular in a lithium-ion battery cell.The electrode arrangement comprises a plurality of first electrodes and a plurality of second electrodes, which in an electrode stack are alternately stacked on top of each other in a stacking direction or wound in an electrode roll around a roller axis and alternately follow one another in a radial direction (r), wherein the first electrodes and the second electrodes each have an electrically conductive support layer and on at least one side of the support layer a coating of an active material and an edge section of each support layer is designed as a contact section which is at least partially free of the coating, wherein the contact sections of the first electrodes are expediently electrically connectable to a first connection element and the contact sections of the second electrodes are expediently electrically connectable to a second connection element.According to the invention, an electrically conductive material is introduced between the contact sections of adjacent first electrodes in order to electrically connect the contact sections of the first electrodes to one another. Similarly, an electrically conductive material is also introduced between the contact sections of adjacent second electrodes in order to electrically connect the contact sections of the second electrodes to one another.

[0011] The electrically conductive material placed between the contact sections of adjacent first electrodes creates electrical contact between the first electrodes, and similarly, the second electrodes create electrical contact between them. The sections of the first electrodes electrically contacted via the conductive material are advantageously located on one side of the electrode arrangement, while the sections of the second electrodes electrically contacted via the conductive material are located on the opposite side of the electrode arrangement.This results in electrically conductive contact sections on the first side of the electrode assembly for electrical contacting the first electrodes and electrically conductive contact sections on the second side of the electrode assembly for electrical contacting the second electrodes. These can be reliably and easily connected to terminal elements to ensure an electrical current flow with a homogeneous current density distribution via the terminal elements and the contact sections. The first electrodes can be the anodes and the second electrodes can be the cathodes of the electrode assembly, or vice versa.

[0012] In the electrode arrangement according to the invention, an electrically insulating separator is preferably arranged between each electrode of the plurality of first electrodes and a second electrode of the plurality of second electrodes adjacent to it in the electrode stack. The electrical separators ensure that the first and second electrodes have no electrical contact with each other, thereby preventing electrical short circuits. The separators arranged between a first electrode and a second electrode expediently extend over the areas of the first and second electrodes that are coated with the active material.In the edge sections (contact sections) where there is no coating of an active material on the support layer of the respective electrodes, the adjacent first and second electrodes expediently have a distance from each other that ensures that the electrically conductive support layers of the first and second electrodes do not come into contact with each other.

[0013] The substrate layer of the first electrodes and the substrate layer of the second electrodes can be made of different materials. For example, the first electrodes can have a substrate material of copper foil or copper sheet, and the substrate material of the second electrodes can be aluminum foil or aluminum sheet.

[0014] The electrically conductive material inserted between adjacent first electrodes can be the same material as the substrate material of the first or second electrodes, or a different material. The same applies to the electrically conductive material inserted between adjacent second electrodes. Preferably, the electrically conductive material is a plastically deformable material, and in particular, a pasty or viscous material at room temperature or at temperatures above room temperature. This allows the electrically conductive material to be applied to a contact section of the substrate layer of a lower electrode during the manufacturing process, and then plastically deformed, e.g., by...By pressing down with a roller or a stamp, and then applying an upper electrode, the electrically conductive material is pressed against the lower electrode by the upper electrode in the contact sections of the electrodes that are free of the coating. Due to the plastic deformability of the electrically conductive material, this creates a force-fit connection that generates good mechanical and electrical contact between the contact sections of the first electrode and the electrically conductive material. The same applies to the contact sections of the second electrode and the electrically conductive material introduced between adjacent second electrodes.

[0015] Advantageously, when applied to the electrode substrate layers, the electrically conductive material is in the form of a metal paste that can be plastically deformed.

[0016] Preferably, the electrically conductive material has a composition that, when applied to the electrode substrates, allows it to form a metallurgical bond with the substrate material of the first and second electrodes. For this purpose, the electrically conductive material can, for example, be flowable at the processing temperature, and in particular liquid, viscous, or pasty. The electrically conductive material can also be melted by applying heat before or during application to the electrode substrates in order to become flowable and to form a mechanically and electrically conductive bond, in particular a metallurgical bond, with the substrate materials of the first and second electrodes. The electrically conductive material is preferably a metal from the group comprising silver, gold, aluminum, and lead, as well as mixtures or alloys of these metals.Other suitable materials that are both plastically deformable and possess sufficiently good electrical conductivity include, for example, graphite, graphene, or polyaniline. The electrically conductive material is particularly preferably a solder, especially a solder containing lead, tin or a tin alloy, zinc, or copper, or an alloy of these materials.

[0017] The electrically conductive material preferably extends in the edge region (edge ​​section) over the entire height in the stacking direction (or in the radial direction) between the adjacent first electrodes, i.e., between a lower first electrode and a first electrode arranged above it, so that the edge section of the support layer of the lower first electrode and the edge section of the support layer of the first electrode arranged above it are electrically contacted with each other via the electrically conductive material. The same applies to the second electrodes. In a lateral direction (i.e., in a direction perpendicular to the stacking direction), the electrically conductive material preferably extends over the entire length (in its longitudinal direction) of the respective edge section (contact section) of the first and second electrodes, respectively.

[0018] In a transverse direction (i.e., in a direction perpendicular to the stacking direction and perpendicular to the longitudinal direction of the edge sections), the electrically conductive material preferably does not extend to the edge of the laterally adjacent electrodes of the opposite polarity. This prevents short circuits because, in the transverse direction, a free, electrically insulating gap exists between the electrically conductive material and the laterally adjacent electrodes (of the opposite polarity).

[0019] A particularly advantageous feature of the electrode arrangement according to the invention is the reliable contact of the electrodes, especially the edge sections of the support layers that serve as contact sections, as well as improved heat transfer in these edge sections. This is ensured by the invention through the stable mechanical and electrically conductive connection of the edge sections of superimposed first electrodes and the edge sections of superimposed second electrodes with the electrically conductive material.

[0020] Another aspect of the invention relates to a manufacturing process for producing an electrode arrangement for a battery cell, in particular for a lithium-ion battery cell, comprising the following steps:

[0021] • Providing at least one first electrode, one second electrode, one electrically insulating first separator and one electrically insulating second separator, wherein the first electrode and the second electrode each comprise an electrically conductive support layer and a coating of an active material on at least one side of the support layer, and an edge section of each support layer is designed as a contact section which is at least partially free of the coating,

[0022] • Generating at least one electrode arrangement by stacking or placing on top of each other the first electrode, the first separator, the second electrode and the second separator, wherein the contact section of the first electrode protrudes on a first side of the electrode arrangement over the two separators and the second electrode and the contact section of the second electrode protrudes on a second side of the electrode arrangement over the two separators and the first electrode.

[0023] In this process, an electrically conductive material is applied to the contact sections of the first electrode and the second electrode when generating the electrode arrangement.

[0024] According to this aspect of the invention, an electrode arrangement comprising at least one first electrode, at least one second electrode, at least one electrically insulating first separator and at least one electrically insulating second separator is described, wherein the first electrode and the second electrode each comprise an electrically conductive support layer and, on at least one side of the support layer, a coating of an active material, and an edge section of each support layer is designed as a contact section which is at least partially free of the coating, and the electrode arrangement is formed by stacking or placing on top of each other the first electrode, the first separator, the second electrode (2) and the second separator, and optionallyfurther electrodes and separators, is generated, wherein the contact section of the first electrode protrudes on a first side of the electrode arrangement over the two separators and the second electrode, and the contact section of the second electrode protrudes on a second side of the electrode arrangement over the two separators and the first electrode, wherein an electrically conductive material is applied to the contact sections of the first electrode and the second electrode.

[0025] In a first variant of the manufacturing process, the first electrode, the first separator, the second electrode and the second separator of each electrode arrangement are stacked along a stacking direction to form an electrode stack, whereby several such electrode arrangements can also be stacked on top of each other in the stacking direction.

[0026] In this first variant of the manufacturing process, when stacking the multiple electrode assemblies to form the electrode stack, the contact sections of the first electrodes, which are stacked one above the other, are preferably arranged on the first side of the electrode assembly, and the contact sections of the second electrodes, which are stacked one above the other, are arranged on the second side of the electrode assembly in a aligned manner. In this process, the electrically conductive material is located between the contact sections of the first electrodes that are adjacent to each other in the stacking direction on the first side of the electrode assembly, and the contact sections of the first electrodes that are adjacent to each other in the stacking direction are electrically connected to each other.Accordingly, on the second side of the electrode arrangement, the electrically conductive material is placed between the contact sections of the second electrodes that are adjacent to each other in the stacking direction, and the contact sections of the second electrodes that are adjacent to each other in the stacking direction are electrically contacted with each other.

[0027] In a second variant of the manufacturing process, an electrode arrangement comprising a first electrode, a first separator, a second electrode and a second separator is rolled prismatically or cylindrically around a roller axis to form an electrode roll (so-called "Jelly Roll").

[0028] In this second variant of the manufacturing process, when one electrode arrangement is rolled into an electrode roll, the contact sections of the first electrode on the first side of the electrode arrangement and the contact sections of the second electrode on the second side of the electrode arrangement are preferably arranged one above the other, aligned with each other in the direction of the roll axis. In this arrangement, the electrically conductive material is located between the contact sections of the first electrode of radially adjacent layers of the electrode roll on the first side of the electrode arrangement, and the contact sections of the radially adjacent layers of the first electrode are thereby electrically connected to each other.Accordingly, on the second side of the electrode arrangement, the electrically conductive material is located between the contact sections of the second electrode of radially superimposed layers of the electrode roll, and the contact sections of the radially adjacent layers of the second electrode are thereby electrically contacted with each other.

[0029] In a third variant of the manufacturing process, the separators are formed from a strip of electrically insulating, flexible material by folding the strip in a zigzag pattern around fold lines perpendicular to a stacking direction and stacked into a Z-stack with successive layers of separators. Between successive layers of the Z-stack, a first electrode and a second electrode, in the form of flat blanks, are alternately placed to create an electrode arrangement consisting of a first electrode, a first separator, a second electrode, and a second separator, all aligned one above the other.

[0030] In this third variant of the manufacturing process, when inserting the first and second electrodes between the successive layers of the separators of the Z-stack, the contact sections of the first electrodes, which are stacked one above the other, are preferably arranged on the first side of the electrode arrangement, and the contact sections of the second electrodes, which are stacked one above the other, are arranged on the second side of the electrode arrangement, each in alignment with the other. The electrically conductive material is placed between the contact sections of the first electrodes that are adjacent to each other in the stack direction on the first side of the electrode arrangement, thus creating electrically conductive contact between the contact sections of the first electrodes that are adjacent to each other in the stack direction.Accordingly, on the second side of the electrode arrangement, the electrically conductive material is placed between the contact sections of the second electrodes that are adjacent to each other in the stacking direction, and thus the contact sections of the second electrodes that are adjacent to each other in the stacking direction are electrically contacted with each other.

[0031] In all variants of the manufacturing process, the second side of the electrode assembly is advantageously positioned opposite the first side. This allows the first electrodes to be contacted on the first side of the assembly via first connection elements, which can be electrically connected to the contact sections on this first side. The second electrodes can be contacted by means of second connection elements, which are electrically connected to the contact sections on the second side. For the application of the electrically conductive material to the electrode substrates, it is advantageous if the electrically conductive material is plastically deformable at the ambient temperature at which the application is carried out.This ensures that the edge sections of the support layers of the first electrodes (e.g., the anodes) and the second electrodes (e.g., the cathodes) can be electrically contacted with each other. In particular, this makes it possible to completely fill the gap between a lower anode and an adjacent upper anode in the stacking direction with the electrically conductive material, thus creating a reliable and permanent electrical contact between the lower and upper anodes. The same applies to the cathodes. Specifically, after applying the electrically conductive material to a lower anode or lower cathode, the applied amount of the conductive material can first be compressed in the stacking direction of the electrode arrangement, and then an upper anode or cathode can be placed on top.An upper cathode is applied, whereby the electrically conductive material expands due to its plastic elasticity and is compressed between the lower and upper anode or cathode. In this way, a good and permanent electrical contact is created between the lower and upper anode or between the lower and upper cathode.

[0032] It is also advantageous if the electrically conductive material is fluid at temperatures above room temperature. If this is not already the case due to the material's properties, the electrically conductive material can be made fluid by adding a solvent. Existing fluidity of the electrically conductive material, inherent to the material itself, can also be improved by adding a solvent and / or by heating. For example, if the conductive material is a solder that is solid, especially at room temperature, it can be made fluid by heating. High fluidity of the electrically conductive material facilitates easier processing during the manufacturing process and ensures that the electrically conductive material bonds well and evenly with the edge sections of the first or second layer.the second electrodes connect, thereby achieving good and lasting electrical contact between the first electrodes and good electrical contact between the second electrodes.

[0033] Simple handling is achieved when the electrically conductive material is in the form of a flat strip. This flat strip can be designed as a flat strip with a flat underside and a flat top side, and in this form is placed between two adjacent support layers of the first or second electrodes, so that the underside of the strip makes contact with the support layer of a lower electrode and the top side of the strip makes contact with the support layer of an upper electrode. Alternatively, the strip can also be corrugated and inserted in this form between two adjacent support layers of the first or second electrodes. In another alternative, a initially flat strip can be bent or folded around a longitudinal axis into a C-shape before being inserted in this form between the support layers of adjacent electrodes.

[0034] Preferably, the electrically conductive material is initially in the form of a wire, which is rolled onto the contact sections of the first electrode and the contact sections of the second electrode during application. This ensures good, continuous contact between the electrically conductive material and the surface of the support layer of the first electrodes (e.g., the anodes) or the second electrodes (e.g., the cathodes), resulting in a permanently good, firm, and reliable electrical contact between the first and second electrodes.

[0035] Alternatively, the electrically conductive material can be designed as a hollow profile or body, for example, in the form of a tube or a hollow rectangular profile. This achieves good deformability of the electrically conductive material inserted between the support layers of adjacent electrodes, because the hollow profile of the electrically conductive material can be easily compressed when the electrodes are stacked. Furthermore, it is possible to form the electrically conductive material from the material of the support layer of the first or second electrodes. For this purpose, for example, the electrically conductive material can be formed on the first side of the electrode assembly by rolling, bending, crimping, or folding the protruding edge section of the support layer of the first electrodes.Similarly, the electrically conductive material on the second side of the electrode assembly can also be formed from the material of the support layer of the second electrodes. This enables a particularly efficient manufacturing process without the use of additional materials.

[0036] In a preferred embodiment, the electrically conductive material is composed of the material of the support layer of the first electrodes and / or the support layer of the second electrodes and an electrically conductive and preferably deformable filler material, wherein the filler material is introduced into the rolled, bent, crimped, or folded area of ​​the protruding edge section of the support layer of the first electrodes and / or the second electrodes. This results in particularly good deformability of the electrically conductive material introduced between the support layers of adjacent electrodes.

[0037] The deformable consistency of the electrically conductive material when applied to the electrode substrates, and / or the shapes of the electrically conductive material described above, ensures complete filling of the gap between the substrates of adjacent electrodes, thus guaranteeing reliable contact. The material's inherent deformability, whether due to the material itself or its geometry, compensates for tolerances, improves contactability, and creates a homogeneous, flat end face. Furthermore, the applied electrically conductive material can be further processed in subsequent steps, such as turning, grinding, rolling, glass bead blasting, etc.The electrodes are processed and reshaped to achieve a uniform, flat surface and a more homogeneous or larger cross-section for contact with the battery cell's terminals and contacts. The electrode assembly can be manufactured, for example, as an electrode roll (so-called "jelly roll"), a Z-shaped stacked arrangement ("Z-folding"), or an electrode stack by alternately stacking or laying multiple layers of electrodes and separators on top of each other in a Z-shape, or by rolling them into an electrode roll. To manufacture the electrodes, a coating of an active material, such as graphite or lithium iron phosphate, or comparable electrode materials, is first applied to a thin substrate layer, such as a copper or aluminum foil.The coating can be applied to the substrate using either a wet or dry process ("wet coating," "dry coating") and then compacted by a subsequent calendering process. The substrate layers with the applied active material are then cut to the required format and rolled, folded, or stacked with a separator film in between. When coating the substrate layers with the active material, the edges of the substrate layers are left free of the coating. These edges, free of the active material, form contact points where the electrodes are later electrically connected.

[0038] This results in the support layers (e.g., the copper and / or aluminum sheets or the copper and / or aluminum foils) forming an edge section with a protrusion at opposite edges of the electrode arrangement, which is used for contacting. Due to the layered structure of the electrodes and separators, a gap is created between the overlapping protrusions, which, according to the invention, is filled with the electrically conductive material to electrically connect the electrodes, and in particular the edge sections of the support layers, to one another. The protruding sheet or foil areas (edge ​​sections of the support layers) can then be bent to create or enable continuous contact.In the manufacturing process, during the stacking of the electrodes and separators, the electrically conductive material is introduced into the space between adjacent electrodes at the edge of the electrode arrangement. This space is preferably completely filled with the electrically conductive material, at least in the stacking direction (in the case of a stacked electrode arrangement) or in the radial direction (in the case of a rolled electrode arrangement). This ensures continuous, planar contact between the first electrodes (e.g., the anodes) and the second electrodes (e.g., the cathodes) without further deformation of the protruding edge sections of the support layers (sheets or films), or is already fully or partially achieved by the introduced electrically conductive material.

[0039] The electrically conductive material can be provided in a solid or pasty form or in liquid form.

[0040] The electrically conductive material used should preferably already possess sufficient compressibility, or a calibration process is used before layering to ensure that the thickness of the applied electrically conductive material completely fills the space, at least in the stacking direction for an electrode stack or in the radial direction for an electrode roll, without impairing the winding, folding or stacking process.

[0041] If the electrically conductive material is solid or pasty, its introduction during the manufacturing process of the electrode assemblies, and especially during the stacking of the electrodes and separators, is facilitated by rolling, folding, or stacking it at the appropriate location in the space between adjacent first electrodes (e.g., anodes) and between adjacent second electrodes (e.g., cathodes). A particular advantage for the manufacturing process is that the extent of the edge regions (protrusions of the support layers that are free of the active material coating), especially in a direction perpendicular to the stacking direction (in the case of an electrode stack), is minimized.in the axial direction (in the case of an electrode roll), can be minimized, particularly compared to known methods for contacting the electrodes of an electrode arrangement, in which laterally projecting strip elements (so-called "tabs") are used and electrically contacted together, for example, by soldering or by means of clamping elements (as, for example, in DE 10 2022 103 728 Bl). In the inventive method, less material is therefore required for the carrier layers (sheets or films), or more surface area is available for coating the carrier layers with the active materials. Likewise, the space required for contacting the electrodes within a battery cell can be reduced, which enables a compact battery cell design.

[0042] In another aspect, the invention relates to a battery cell comprising a cell housing and at least one electrode arrangement housed therein according to the invention.

[0043] In a preferred embodiment of the battery cell, the cell housing contains at least two contacts, wherein a first contact is electrically conductively connected to the contact sections of the first electrodes and the electrically conductive material inserted between them, and a second contact is electrically conductively connected to the contact sections of the second electrodes and the electrically conductive material inserted between them. The connection can preferably be made via connecting elements that are electrically conductively connected between the contact sections of the first and second electrodes of the electrode arrangement and the corresponding contacts of the cell housing. The connecting elements can, for example, be designed as electrical conductors or cables. The connecting elements can also be formed by a solder material used when soldering the contacts to the contact sections of the first and second electrodes of the electrode arrangement.Furthermore, the connecting elements can also be formed by a weld seam, which is created when the contact sections of the first or second electrodes are welded to the associated contacts of the cell housing.

[0044] In a preferred embodiment of the battery cell, the cell housing is designed as a prismatic battery cell housing and has a base, a top surface arranged parallel to and at a distance from the base, and at least four side surfaces, each arranged between the base and the top surface. In this case, the electrode arrangement housed in the cell housing is advantageously shaped as an electrode stack.

[0045] Preferably, the prismatic battery cell housing is composed of a first molded part and a second molded part, wherein the first molded part contains the base surface and the top surface as well as at least one of the side surfaces, the second molded part contains the remaining side surfaces and the first molded part is connected to the second molded part by an joining connection.

[0046] The two molded parts are shaped so that they can be precisely fitted together to form a closed prismatic housing. During the manufacturing process of the prismatic battery cell housing, the initially separate molded parts are positioned so that they interlock and, in particular, abut each other at their free outer edges. This allows for a strong connection between the two molded parts, for example, by laser welding, creating a closed, stable housing.

[0047] In a preferred embodiment, the battery cell housing comprises four side surfaces, wherein the first molded part contains one of these four side surfaces and the second molded part contains the remaining three side surfaces. In this preferred embodiment, both the first and the second molded part are advantageously egg-shaped. In a preferred embodiment, the second molded part has at least two contacts, each configured for electrical contact with the contact sections of the electrode stack that is accommodated by the battery cell housing. The contacts of the second molded part are configured for electrical connection with the contact sections of the electrode stack, the electrically conductive connection being made, for example, by a laser or by soldering, whereby the contact sections of the electrode stack are welded or soldered to the contacts of the second molded part using the laser.The two-part design of the battery cell housing allows the electrically conductive connection between the contact sections of the electrode stack and the contacts of the second molded part to be made before the two molded parts are joined to form the closed cell housing. This simplifies the contacting process, as the tools and materials used to create the electrical contact, such as lasers or soldering irons and solder, can be more easily brought into contact with the contact surfaces of the electrical connection between the contact sections of the electrode stack and the contacts of the second molded part.

[0048] After the contact sections of the electrode stack have been made contact with the contacts of the second molded part, the two molded parts can be positioned and engaged so that they form a closed housing that completely surrounds the electrode stack. To close the housing and stabilize the cell housing, the two molded parts can be joined by a circumferential weld, with the weld running particularly along the free outer edges of the first and second molded parts.

[0049] The second molded part expediently includes at least one filling opening for introducing an electrolyte into the closed cell housing. Furthermore, the second molded part expediently includes at least one rupture membrane. The rupture membrane represents a predetermined breaking point or a safety valve in the cell housing and fulfills a protective function. In particular, the rupture membrane is intended to provide pressure relief in the event of battery cell malfunctions, prevent uncontrolled rupture of the battery cell housing, prevent a thermal chain reaction (thermal runaway) in the event of battery cell overheating, and ensure the mechanical stability of the battery cell housing.

[0050] For precise positioning and fixing of the electrode stack in the cell housing, the first molded part and / or the second molded part advantageously includes grooves which fix a desired position of the electrode stack arranged in the cell housing.

[0051] The first and second molded parts can each be formed from a sheet of metal, for example, by forming, in particular by bending or deep drawing. Aluminum or steel sheets, for example, can be used as the metal sheets for manufacturing the molded parts. Preferably, the sheets have a thickness in the range of 0.1 mm to 1.0 mm, and particularly preferably between 0.5 mm and 0.8 mm.

[0052] These and other advantages, features, and technical effects of the invention will become apparent from the exemplary embodiments explained in detail below with reference to the drawings. These show:

[0053] Figure 1A: Schematic representation of an embodiment of an electrode stack according to the invention for a battery cell;

[0054] Figure 1B: Detail view of a cross-section of the electrode stack from Figure 1A in the center of the electrode stack;

[0055] Figure IC: Detailed view of a cross-section of the electrode stack of Figure 1A in the area of ​​the edge section on a first side (a) of the electrode stack;

[0056] Figure ID: Detailed view of a cross-section of the electrode stack of Figure 1A in the area of ​​the edge section on one of the second sides (b) of the electrode stack opposite the first side;

[0057] Figure 2: Schematic representation of a further embodiment of an electrode arrangement according to the invention in the form of an electrode roll with a detailed cross-sectional view in a radial plane; Figure 3: Schematic cross-sectional view of a basic structure of a

[0058] Electrode arrangement that is created in an intermediate step of the manufacturing process;

[0059] Figure 4: Schematic representation of the winding of a web-shaped

[0060] Electrode arrangement for an electrode roll according to Figure 2;

[0061] Figure 5: Schematic representation of the stacking of an electrode arrangement into a Z-stack;

[0062] Figure 6A Detailed view of a cross-section of an embodiment of an electrode stack in the area of ​​the edge section on a second side (b), wherein the electrode stack has an electrically conductive material between adjacent electrodes, which is formed as a C-shaped bent band,

[0063] Figure 6B Detailed view of a cross-section of an embodiment of an electrode stack in the area of ​​the edge section on a second side (b), wherein the electrode stack has an electrically conductive material between adjacent electrodes, which is designed as a flat, planar band,

[0064] Figure 6C Detailed view of a cross-section of an embodiment of an electrode stack in the area of ​​the edge section on a second side (b), wherein the electrode stack has an electrically conductive material between adjacent electrodes, which is designed as a corrugated band, and

[0065] Figure 6D Detailed view of a cross-section of an embodiment of an electrode stack in the area of ​​the edge section on a second side (b), wherein the electrode stack has an electrically conductive material between adjacent electrodes, which is designed as a hollow profile,

[0066] Figure 6E Detailed view of a cross-section of an embodiment of an electrode stack in the region of the edge section on a second side (b), wherein the electrode stack has an electrically conductive material between adjacent electrodes, which is formed from the material of the carrier film of the electrodes by bending or crimping the carrier film protruding at the edge section of the electrodes, and

[0067] Figure 6F shows a detailed cross-section of an embodiment of an electrode stack in the area of ​​the edge section on a second side (b), wherein the electrode stack has an electrically conductive material between adjacent electrodes, which is formed from the material of the carrier film of the electrodes by bending or crimping the carrier film protruding at the edge section of the electrodes and by introducing an electrically conductive filler material into the bent or crimped area;

[0068] Figure 7: Detailed view of a longitudinal section of the electrode stack of Figure 1A in the area of ​​the contact section of an electrode on the second side (b) of the electrode stack, wherein a recess for the introduction of an electrolyte is provided in the area of ​​the contact section;

[0069] Figure 8 perspective view of a prismatic battery cell with a cell housing in which an electrode arrangement, in particular an electrode stack, is inserted according to the invention;

[0070] Figure 9 perspective view of the two housing parts of a preferred embodiment of the prismatic cell housing of Figure 8 for a battery cell according to the invention before the insertion and contacting of an electrode arrangement, in particular an electrode stack, according to the invention;

[0071] Figure 10 perspective view of one of the two housing parts of the embodiment of the prismatic cell housing of Figure 8 after the insertion of an electrode arrangement and contacting of the contact sections of the electrode arrangement with contacts of the cell housing;

[0072] Figure 11 shows a perspective view of the preferred embodiment of a prismatic battery cell with a cell housing composed of the two housing parts of Figure 9 after the insertion and contacting of the electrode arrangement and after welding the two housing parts together to form a closed cell housing.

[0073] Figure 1 shows a schematic side view of a first embodiment of an electrode arrangement according to the invention in the form of an electrode stack S. The electrode stack S comprises a plurality of first electrodes 1, a plurality of second electrodes 2, and a plurality of separators 7, which are stacked on top of each other in a stacking direction s relative to the electrode stack S. The electrode stack S has a first side a (right side in the representation of Figure 1A) and a second side b (left side in the representation of Figure 1A). The first side a and the second side b of the electrode stack S each contain an edge section that serves as a contact section 5 for electrically connecting the first electrodes 1 and the second electrodes 2. The contact section 5-1 on the first side a is electrically connected to a first terminal element 8-1.Accordingly, the contact section 5-2 on the second side b is electrically connected to a second terminal element 8-2. An electric current can be conducted via the terminal elements 8-1 and 8-2 from the electrode stack S to a load (when discharging the battery cell) or from a power source to the electrode stack S (when charging the battery cell).

[0074] To illustrate the structure of the electrode stack S, consisting of the first electrodes 1, the second electrodes 2, and the separators 7 arranged between the first electrodes 1 and the second electrodes 2, Figure 1B shows a detailed cross-sectional view of the central region of the electrode stack S, labeled "Figure 1B" in Figure 1A. As can be seen in Figure 1B, the electrode stack S contains a plurality of first electrodes 1 and a plurality of second electrodes 2, as well as separators 7, each arranged between a first electrode 1 and a second electrode 2 to electrically isolate the first electrodes 1 from the second electrodes 2. The sequence of electrodes 1, 2 and the separators 7 arranged between them in the stacking direction s is shown in detail in Figure 1B by the fact that the successive electrodes 1, 2 in the stacking direction s are designated with ascending reference numerals 1-1, 1-2, 1-3, etc. and 2-1, 2-2, 2-3, etc.w. and the separators arranged in between are designated with ascending reference numerals 7-1, 7-2, etc.

[0075] The first electrodes 1 comprise an electrically conductive support layer 3, 3-1, which is coated on both sides with a coating 4 of an active material. Similarly, each of the second electrodes 2 also contains a support layer 3, 3-2, which is likewise coated on both sides with a coating 4 of an active material. The materials of the support layer 3-1 of the first electrodes can be

[0076] The coating 4 of the first electrode 1 (anode) and the support layer 3-2 of the second electrode 2 can be the same or different. For example, in an electrode arrangement for a lithium-ion battery cell, the first electrode 1 can be configured as anodes and have a support layer 3-1 made of copper foil. The second electrode 2 can be configured as cathodes and have a support layer 3-2 made of aluminum foil. The coating 4 of the first electrode 1 (anode) can be a graphite coating, and the coating 4 of the second electrode 2 (cathode) can be a lithium iron phosphate coating or a nickel-cobalt oxide coating. A separator 7 made of an electrically insulating material is arranged between each first electrode 1 (anode) and a second electrode 2 (cathode). The separators 7 can each be made of the same electrically insulating material.However, it is also possible to use different separators 7-1, 7-.

[0077] 2 different materials are used. The separators 7; 7-1, 7-2 isolate a first electrode 1 (anode) from an adjacent second electrode 2 (cathode), thus preventing a short circuit.

[0078] Figures IC and ID show the lateral edge sections of the electrode stack S on the first side a (Figure IC) and on the second side b (Figure ID) in detail. Figures IC and ID show that the support layers 3-1 of the first electrodes 1 and the support layers 3-2 of the second electrodes 2 are each free of the active material coating 4 in an outer edge section. These coating-free edge sections of the support layers 3, 3-1, 3-2 each form a contact section 5, 5-1, 5-2. Figure IC shows the contact section 5-1 of the first electrodes 1, and Figure ID shows the contact section 5-2 of the second electrodes 2.In the area of ​​the contact sections 5; 5-1, 5-2, the support layers 3; 3-1, 3-2 form a lateral overhang (in a transverse direction q) by the lateral edge sections 3-1 of the first electrodes 1 projecting on the first side a over the second electrodes 2 and over the separators 7 (Figure IC). Similarly, the lateral edge sections of the support layer 3-2 of the second electrodes 2 project on the second side b (in transverse direction q) over the first electrodes 1 and over the separators 7. This creates a gap between successive first electrodes 1 in the stacking direction s on the first side a (in the vertical direction). Similarly, a gap is created between successive second electrodes 2 in the stacking direction s on the second side b in the area of ​​the edge section.

[0079] According to the invention, these spaces between successive first electrodes 1 and between successive second electrodes 2 are at least partially, and in particular completely in the stacking direction s, filled with an electrically conductive material 6. In the examples shown in Figures IC and ID, an electrically conductive material 6-1 is introduced on the first side a in the region of the edge section 5-1 of the first electrodes 1. Correspondingly, an electrically conductive material 6-2 is introduced on the opposite side b between successive second electrodes 2 in the region of the edge section 5-2. The electrically conductive material 6-1 electrically connects the edge sections 5-1 of the support layers 3-1 of the first electrodes 1 to each other, so that the first electrodes 1 are electrically connected to each other.Accordingly, the electrically conductive material 6-2 electrically connects the edge sections 5-2 of the support layers 3-2 of the second electrodes 2, so that the second electrodes 2 are electrically connected to each other. To produce the electrode stack S shown in Figure 1A, prefabricated first electrodes 1 and prefabricated second electrodes 2 are stacked on top of each other in the stacking direction s, with a separator 7 being inserted between each first electrode 1 and an adjacent second electrode 2. The first electrodes 1, the second electrodes 2, and the separators 7 are arranged one above the other in a plate-like and aligned manner, so that a block-shaped electrode stack S is formed.

[0080] In this process, the electrically conductive material 6-1 or 6-2 is applied to the edge sections 5-1 or 5-2 of the support layers 3-1 or 3-2 of the first electrodes 1 and the second electrodes 2, respectively, in the region of the edge sections 5-1 or 5-2. The electrically conductive material 6-1, 6-2 is preferably plastically deformable and is, for example, in the form of a flat strip or wire, first placed on the edge section 5-1 of a first electrode 1 and pressed down, for example, with a punch or roller, so that a firm contact, preferably in the form of a metallurgical bond, is formed with the surface of the support layer 3-1 of this electrode 1. Then, a separator 7 and a second electrode 2, another separator 7, and subsequently another first electrode 1 are applied.The laterally projecting edge section 5-1 of the further (upper) first electrode 1 rests on the upper surface of the electrically conductive material 6-1 and is advantageously pressed onto the electrically conductive material 6-1, e.g., with a punch or a roller, to create a firm contact between the underside of the support layer 3-1 and the upper surface of the electrically conductive material 6-1. Advantageously, the electrically conductive material is flowable so that a firm, in particular a metallurgical, connection can be achieved between the electrically conductive material 6-1 and the support layer 3-1 in the region of the edge section 5-1 of the first electrodes 1.If a solder is used as the electrically conductive material, the electrically conductive material can be made fluid by increasing the temperature to a temperature above the melting or flow point of the solder, thereby creating a firm and permanent, materially bonded and electrically conductive connection between the electrically conductive material 6-1 and the support layers 3-1 in the area of ​​the edge section 5-1 of the first electrodes 1.

[0081] The second electrodes 2 are contacted accordingly on the second side b of the electrode stack S during the described fabrication of the electrode stack S. As can be seen from Figures IC and ID, the electrically conductive material 6-1, 6-2 does not extend laterally (opposite the transverse direction q, i.e., towards the center of the electrode stack) to the edges of the separators 7 or the electrodes with the opposite polarity (second electrodes on the first side a or first electrodes on the second side b). This is advantageous because it prevents short circuits. If, for example, the electrically conductive material on the first side a were to come into contact with the edges of the second electrodes 2, there would be a risk of a short circuit between the first and second electrodes.Therefore, a gap preferably exists in the transverse direction q between the electrically conductive material 6-1 and the edges of the second electrodes 2. To avoid unintentional short circuits during the production of the electrode stack S, it is advantageous if the edges of the second electrodes 2 on the first side a are set back in the transverse direction q (i.e., inwards towards the center of the electrode stack S) compared to the separators 7, as shown in Figure IC. The same applies to the electrically conductive material 6-2 and the edges of the first electrodes 1 on the second side b, as shown in Figure ID.

[0082] Figure 2 shows a schematic representation of a second embodiment of an electrode arrangement according to the invention in the form of an electrode coil R in a perspective view and in a sectional view of the insert. The electrode coil R comprises an electrode base structure in the form of an electrode arrangement A, comprising a first electrode 1, a first separator 7-1, a second electrode 2, and a second separator 7-2, as schematically shown in Figure 3, wherein this electrode base structure is web-shaped and wound around a roller axis Ra to form the electrode coil. The winding creates a layered structure, as shown in part in the sectional view in the insert at the bottom right of Figure 2, with a sequence of layers wound around the roller axis Ra, which, for example,In the radial direction r, a sequence comprises a first electrode 1, a separator 7, a second electrode 2, another separator 7, another first electrode 1, and another separator 7, etc. The structure of each of the first electrodes 1 and the second electrodes 2 corresponds to the first embodiment of Figure 1A to ID and consists of a carrier layer 3 (carrier layer 3-1 for the first electrodes 1 and carrier layer 3-2 for the second electrodes 2) and a coating 4 of an active material applied to both sides thereof.

[0083] Figure 4 schematically shows a method for manufacturing the electrode roll R from Figure 2. First, the electrode base structure is produced in the form of the electrode arrangement A shown in section in Figure 3. This electrode base structure is formed in a web shape and comprises a first layer consisting of a web of a first electrode 1, a second layer consisting of a web of a separator 7, a third layer consisting of a web of a second electrode 2, and a fourth layer consisting of a web of another separator 7, as shown in Figure 4. The webs of the first electrode 1 and the webs of the second electrode 2 each contain lateral edge sections that are free of the coating 4. These lateral edge sections serve as contact sections 5-1 for contacting the first electrodes 1 and as contact sections 5-2 for electrically contacting the second electrodes 2, respectively.The tracks of the first electrode 1, the separators 7 and the second electrodes 2 are placed on top of each other in such a way that the lateral contact sections 5 protrude laterally, wherein the lateral contact section 5-1 of the track of the first electrode 1 protrudes on the first side a over the lateral edges of the second electrode 2 and the separators 7 and the lateral contact section 5-2 of the track of the second electrode 2 protrudes on the second side b over the lateral edges of the first electrode 1 and the separators 7, as shown in Figure 4.

[0084] When forming the tracks of the first electrode 1 and the second electrode 2, a strip of electrically conductive material 6-1, 6-2 is applied along the entire longitudinal direction L of the respective electrode track (contact section 5-1 of the first electrode 1, contact section 5-2 of the second electrode 2). The electrically conductive material 6-1, 6-2 is advantageously in the form of a flat strip or wire made of a conductive and elastically deformable material. The strip or wire of the electrically conductive material can then be laid along the longitudinal direction of the track on the respective lateral edge section of the first electrode 1 and the second electrode 2, which forms the respective contact section 5-1, 5-2.To produce an electrically conductive and, in particular, a metallurgically bonded connection between the electrically conductive material 6; 6-1, 6-2 and the surface of the support layer 3-1, 3-2 of the first or second electrode, the electrically conductive material is preferably flowable and is pressed onto the respective lateral edge section of the support layer 3-1 or 3-2, e.g., by means of a calender (roller or press). The thickness of the electrically conductive material 6, 6-1, 6-2 in the radial direction r of the electrode roll R is adjusted such that the electrically conductive material 6, 6-1, 6-2 extends at least to the extent that the space between radially successive first electrodes 1 or the space between radially successive second electrodes 2 (i.e., in the vertical direction) is completely filled. In the transverse direction q (i.e.,The electrically conductive material 6-1, 6-2, perpendicular to the longitudinal direction L of the web and parallel to the roller axis Ra), preferably does not extend to the edge of the laterally adjacent electrodes of the opposite polarity in order to prevent short circuits.

[0085] During the final winding of the web-shaped electrode base structure (electrode arrangement A according to Figure 3), produced as described above, around the roller axis Ra to form the electrode roll R, it is ensured that an electrical contact is established between successive layers of the first electrode 1 in the radial direction r in the region of the contact section 5-1 on the first side a of the electrode roll R, and between successive layers of the second electrode 2 in the region of the contact section 5-2 on the second side b, by means of the electrically conductive material 6, 6-1, 6-2. This results in the individual layers of the first electrode 1 being electrically connected to each other, and correspondingly, the individual layers of the second electrode 2 being electrically connected to each other.It is advantageous if the electrically conductive material 6, 6-1, 6-2 is plastically deformable, since the material is compressed by an elastic prestress between the support layers 3-1 of successive layers of the first electrode 1 and between the support layers 3-2 of successive layers of the second electrode 2 when the electrode roll R is wound up, thereby ensuring a secure mechanical and electrical contact.

[0086] Figure 5 schematically shows a method for manufacturing an electrode arrangement in the form of a so-called "Z-folding". Here, prefabricated, plate-shaped, in particular rectangular, blanks of first electrodes 1 and second electrodes 2 are placed between successive layers of separators 7, the layers of separators 7 being created by zigzag-folding a separator web around fold edges K. The production of the prefabricated blanks of the first electrodes 1 and the second electrodes 2 is carried out as described above for the second embodiment (electrode roll R), with the difference that plate-shaped (e.g., rectangular) blanks are produced here instead of web-shaped electrodes. The blanks of the first electrodes 1 and the second electrodes 2 each have a [missing information] on one side (i.e.,(at an edge of the plate-shaped blank) edge sections are formed which are free of the coating 4 of the active material and serve as contact sections 5; 5-1, 5-1. As in the second embodiment, the edge contact sections 5-1 of the first electrodes 1 and the edge contact sections 5-2 of the second electrodes 2 are provided with the electrically conductive material 6; 6-1 and 6-2 respectively over the entire length of the respective contact section.

[0087] In Z-folding, a web or strip of electrically insulating material is folded in a zigzag pattern around parallel fold edges K to form a separator 7. The folded layers of the separator web are then stacked on top of each other to form a Z-stack Z. During this stacking process, a first electrode 1 and a second electrode 2 are alternately inserted between successive layers of the separator web, as schematically shown in Figure 5. This creates stacked layers of the first electrode 1, the separators 7, and the second electrode 2 arranged one above the other in a stacking direction s. The contact sections 5-1 of the first electrode 1 protrude on a first side a beyond the layers of the separator 7 and the edges of the second electrode 2. Similarly, the contact sections 5-2 of the second electrode 2 protrude on a second side a beyond the layers of the separator 7 and the edges of the second electrode 2.Preferably, the lateral edges of the second electrodes 2 are set back inwards towards the center of the electrode arrangement relative to the lateral edges of the separators 7, as is also the case with the electrode stack S of the first embodiment and can be seen in Figure 5. The same applies to the contact sections 5-2 of the second electrodes 2 on the second side b, which project there beyond the layers of the separator 7 and the edges of the inwardly set-back first electrodes 1.

[0088] During the zigzag-shaped laying of the separator 7 layers and the insertion of the blanks for the first electrodes 1 and the second electrodes 2, an electrically conductive contact is created between successive layers of the first electrodes 1 in the area of ​​the contact sections 5-1 of the first electrodes 1. This is achieved by pressing the electrically conductive material 6-1 between two successive layers of the first electrodes 1 at the contact section 5-1. The same applies to the contact sections 5-2 of successive layers of the second electrodes 2, which are also electrically connected to each other by the electrically conductive material 6-2.

[0089] To produce a battery cell from or with one of the electrode arrangements A, which can be produced according to the embodiments described above, the contact sections 5-1 of the first electrodes 1 are electrically connected to a first terminal element 8-1 and the contact sections 5-2 of the second electrodes 2 are electrically connected to a second terminal element 8-2, as shown schematically in Figure 1 A.

[0090] Figure 6 shows further exemplary embodiments of an electrode arrangement shaped as an electrode stack S according to the invention, in each case showing detailed views of a cross-section of the electrode stack S in the region of the edge section (contact section 5-2) on one side (second side b) of the electrode stack S. The other side (first side a) of the electrode stack can be designed in a corresponding manner.

[0091] Figure 6A shows an embodiment of an electrode stack with an electrically conductive material 6-2 between adjacent second electrodes 2, wherein the electrically conductive material 6-2 is formed as a C-shaped, bent strip. To produce this embodiment, a flat, planar strip is initially rolled into a semicircle around an axis running parallel to a longitudinal edge of the strip. When the electrodes are stacked, the C-shaped strip is electrically contacted onto a protruding edge section of the support layer 3-2 of a (lower) electrode 2. Then, another electrode is placed on top, so that the protruding edge section of the support layer 3-2 of this further electrode lies on the C-shaped, bent strip 6-2 and is electrically contacted with it.This involves pressing the C-shaped bent band (6-2) between the contact sections 5-2 of the electrodes 2, which contributes to a good electrical contact.

[0092] Alternatively to this embodiment, as shown in Figure 6B, a flat, planar band of an electrically conductive material 6-2 can also be inserted between the protruding edge sections of successive support layers 3-2 of the electrodes 2.

[0093] Figure 6C shows an embodiment of an electrode stack with an electrically conductive material 6-2 between the projecting support layers 3-2 of adjacent electrodes 2, wherein the electrically conductive material 6-2 is formed as a corrugated band. As in the embodiment of Figure 6A, the corrugated band of the electrically conductive material 6-2 is inserted and pressed between the projecting edge sections of successive support layers 3-2 of the electrodes 2. The corrugated structure of the electrically conductive material 6-2 facilitates easy compression and good contact, as well as a uniform, flat structure of the electrodes 2 in the area of ​​the contact section 5-2, because the electrically conductive material 6-2 can deflect laterally.

[0094] Figure 6D shows an embodiment of an electrode stack with an electrically conductive material 6-2 between adjacent electrodes, wherein the electrically conductive material 6-2 is designed as a hollow profile. The electrically conductive material 6-2 can, for example, initially be configured as a tube, which, when the electrodes 2 are stacked, is inserted between the protruding edge sections of successive support layers 3-2 of the electrodes 2 and compressed. Due to the compression, the tubular electrically conductive material 6-2 deflects laterally, resulting in a deformation of the tube (6-2) with an oval cross-section, as can be seen in Figure 6D. This achieves good deformability of the electrically conductive material 6-2 inserted between the support layers of adjacent electrodes because the hollow profile of the electrically conductive material 6-2 can be easily compressed when the electrodes are stacked.

[0095] In further embodiments of the electrode stack according to the invention, the electrically conductive material 6-2 can be formed from the material of the electrode carrier film. One such embodiment is shown in Figure 6E. In this embodiment, a slightly larger edge section of each carrier layer 3-1, 3-2, which is free of the coating 4, is selected during the production of the electrodes 1, 2 of the electrode stack than in the embodiments described above. This larger edge section of the carrier layers 3-1, 3-2, free of the coating 4, can then be folded, crimped, or crimped at the outer edge when the electrodes 1, 2 are stacked to form the electrode stack.Figure 6E shows an embodiment in which the laterally projecting edge regions of the carrier layer 3-2 of the second electrodes 2 have been crimped in a circular or cylindrical shape, so that in the illustrated sectional view they form a tubular or cylindrical cross-section of the electrically conductive material 6-2. Figure 6F shows a further developed embodiment of the variant of Figure 6E, wherein the electrically conductive material 6-2 is formed from the material of the carrier film of the electrodes by crimping or crimping the carrier film projecting at the edge section of the electrodes and inserting a filler material 15 into the crimped or crimped area. The filler material 15 is preferably electrically conductive and easily deformable (plastically or elastically).

[0096] In this further developed variant, the electrically conductive material 6-2 is composed of the material of the electrode support layer and the electrically conductive filler material 15. When the electrodes 1, 2 are stacked, the filler material 15 is inserted into the rolled-up, bent, crimped, or folded area of ​​the protruding edge section of the support layer 3-2 of the electrodes 2, so that the filler material 15 is encased by the bent material 6-2 of the support layer 3-2, as can be seen in Figure 6F.

[0097] Figure 8 shows an exemplary prismatic battery cell 10 with a cell housing 11 in which an electrode arrangement shaped as an electrode stack, according to the embodiment shown in Figure 1, is inserted. When the electrode stack is inserted into the cell housing 11, the connection elements 8-1 and 8-2 are conductively connected to contacts 12-1, 12-2, which are arranged in the cell housing 11 and are electrically insulated from the cell housing 11. The connection elements 8-1, 8-2 can be, for example, an electrical conductor, such as a copper wire or cable, or a solder material. The connection of the connection elements 8-1, 8-2 to the contacts 12-1, 12-2 of the cell housing can be made, for example, by laser welding or by soldering.

[0098] In this way, a first contact 12-1 of the cell housing 11 is electrically connected via the connection elements 8-1 on the first side a of the electrode stack to the contact sections 5-1 of the first electrodes 1 and the electrically conductive material 6-1 inserted between them. Similarly, a second contact 12-2 of the cell housing 11 on the second side b of the electrode stack is electrically connected via the connection elements 8-2 to the contact sections 5-2 of the second electrodes 2 and the electrically conductive material 6-2 inserted between them, in order to establish contact between the electrode arrangement and the contacts 12-1, 12-2 of the cell housing 11.

[0099] An electrolyte is introduced into the cell housing 11 to enable an ion flow during operation of the battery cell. The cell housing 11 has at least one filling opening 14 for introducing the electrolyte. To ensure a uniform distribution of the electrolyte within the cell housing 11, a recess 9 is provided on the second side b of the electrode arrangement in the contact sections 5-2 of the first electrodes 1 and in the electrically conductive material 6-2 introduced there between the support layers 3-2 of adjacent electrodes 2, as shown in Figure 8. Similarly, or alternatively, a (further) recess 9 can also be provided on the first side a of the electrode arrangement in the area of ​​the contact sections 5-1 of the first electrodes 1 and in the electrically conductive material 6-1 introduced there.

[0100] Furthermore, the cell housing 11 expediently contains at least one rupture membrane 13. The rupture membrane 13 represents a predetermined breaking point or a safety valve in the cell housing and fulfills a protective function. In particular, the rupture membrane is intended to provide pressure relief in the event of malfunctions of the battery cell, prevent uncontrolled bursting of the battery cell housing, prevent a thermal chain reaction (thermal runaway) in the event of overheating of the battery cell, and ensure the mechanical stability of the battery cell housing.

[0101] In a preferred embodiment, the cell housing 11 is composed of two molded parts 20, 25. In the embodiment shown in Figures 9 to 11, the cell housing 11 is designed as a right prism with a base G, a top surface D arranged parallel to and at a distance from the base, and four side surfaces Fl, F2, F3, F4, wherein the four side surfaces are each arranged between the base and the top surface and connect them in the fully assembled state. In Figure 9, the two molded parts 20, 25 are shown as a set in their unassembled state. The two molded parts 20, 25 are each U-shaped (when viewed from the free side edges of the molded parts), as can be seen in Figure 9. Here, a first molded part 20 includes the base G and the top surface D as well as one of the four side walls F4 of the right prism, and a second molded part 25 contains the remaining three side walls Fl, F2, F3 of the right prism.The second molded part 25 further comprises the functional elements of a burst membrane 13 and a filling opening 14 for filling the battery cell with an electrolyte, as well as electrical terminals in the form of contacts 12-1, 12-2. The two molded parts, 20, 25 are matched in their shape and geometry so that they can be placed against each other or engaged with each other to form a closed housing, whereby after a precise fit between or engagement of the two molded parts 20, 25, a closed cell housing 11 can be formed that completely surrounds an electrode stack inserted therein.

[0102] One advantage of this design is that all functional elements can be contained in one of the two molded parts (second molded part 20), thus enabling its production, for example, using a progressive die, while the other molded part (first molded part 25) can be manufactured simply by folding, bending, or folding a blank, such as a sheet metal blank. The first molded part 25 can, for example, be produced from a rectangular sheet metal blank by simple folding, requiring no further processing or assembly steps to create the first molded part 25 shown in Figure 9.

[0103] Accordingly, the second molded part 20 can also be produced from an elongated, rectangular metal sheet by simple bending. To complete the second molded part 20, the functional elements (burst membrane 13, filling opening 14, and the contacts 12-1, 12-2) are inserted into the second molded part 20 in further work steps. After the two molded parts 20, 25 have been produced, the contacts 12-1, 12-2 of the second molded part are electrically connected to the contact sections 5-1, 5-2 of the electrode stack S, as shown in Figure 10. This offers a further advantage in terms of improved accessibility for welding the contact sections 5-1, 5-2 of the electrode stack to the inner surfaces of the contacts 12-1, 12-2 of the second molded part using a laser beam 28, as shown in the schematic diagram of Figure 10.

[0104] The contact sections 5-1, 5-2 of the electrode stack can be made significantly more compact than in the prior art, since no area for length compensation is required, as is the case with the cover assemblies that are initially positioned at an angle and then folded down in the subsequent process. This also results in less mechanical stress being introduced into the contact foils of electrodes 1, 2 during assembly, thus reducing the risk of assembly-related defects or damage.

[0105] After the electrode stack is contacted with the contacts 12-1, 12-2 of the second molded part 20, the first molded part 25 is slid over the electrode stack so that it is completely enclosed by both molded parts 20, 25. The two molded parts 20, 25 are in contact with each other at their free outer edges. The abutting free outer edges of the two molded parts are then welded together using a laser or other welding device, forming a circumferential weld seam 29. This creates a closed battery cell housing in which the electrode stack, electrically connected to the contacts 12-1, 12-2, is located.

[0106] Figure 11 shows a circumferential weld 29, with which the two molded parts 20, 25 were joined together in the last assembly step.

[0107] The described cell housing concept 11 reduces the number of molded parts required for manufacturing the battery cell housing and the number of required process steps. Furthermore, it simplifies the contacting of the contact sections 5-1, 5-2 of the electrode stack with the contacts 12-1, 12-2 of the cell housing 11 and reduces material requirements.

[0108] Reference symbol list

[0109] A Electrode arrangement a first side of the electrode arrangement b second side of the electrode arrangement

[0110] S electrode stack

[0111] Ra roller axis r radial direction s stacking direction

[0112] Z Z-stack

[0113] 1 first electrodes

[0114] 1-1, 1-2, 1-3 individual first electrodes

[0115] 2 second electrodes

[0116] 2-1, 2-2, 2-3 individual second electrodes

[0117] 3 carrier layer

[0118] 3-1, Support layer of a first electrode

[0119] 3-2 Carrier layer of a second electrode

[0120] 4 coating made of active material

[0121] 5 contact sections

[0122] 5 - 1 , Contact sections of the first electrodes

[0123] 5-2 Contact sections of the second electrodes

[0124] 6 electrically conductive material

[0125] 6-1 Electrically conductive material applied to a contact section of a first electrode

[0126] 6-2 Electrically conductive material applied to a contact section of a first electrode 7 Separators

[0127] 7-1 first separator

[0128] 7-2 second separator

[0129] 8-1 first connection element 8-2 second connection element

[0130] 9 Recess for introducing an electrolyte

[0131] 10 battery cells

[0132] 11 cell casings

[0133] 12-1, 12-2 Cell casing contacts 13 Burst membrane

[0134] 14 Filling opening for introducing an electrolyte

[0135] 15 Filling material

[0136] 20 second molded part

[0137] 25 first molded part 28 laser beam

[0138] 29 weld seam

Claims

Claims 1. Electrode arrangement, in particular in the form of an electrode stack (S) or an electrode roll (R), for a battery cell, in particular for a lithium-ion battery cell, comprising a plurality of first electrodes (1) and a plurality of second electrodes (2) which are alternately stacked on top of each other in a stacking direction (s) or wound up to form an electrode roll (R) in the electrode arrangement as an electrode stack (S) and alternately follow one another in a radial direction (r), wherein the first electrodes (1) and the second electrodes (2) each have an electrically conductive support layer (3) and a coating (4) of an active material on at least one side of the support layer (3), and an edge section of each support layer (3) is designed as a contact section (5) which is at least partially free of the coating (4), characterized in thatthat an electrically conductive material (6-1) is inserted between the contact sections (5-1) of adjacent first electrodes (1) in order to electrically connect the contact sections (5-1) of the first electrodes (1) to each other, and that an electrically conductive material (6-2) is inserted between the contact sections (5-2) of adjacent second electrodes (2) in order to electrically connect the contact sections (5-2) of the second electrodes (2) to each other.

2. Electrode arrangement according to claim 1, characterized in that an electrically insulating separator (7; 7-1, 7-2) is arranged between an electrode (1-1, 1-2, 1-3) of the plurality of first electrodes (1) and a second electrode (2-1, 2-2, 2-3) of the plurality of second electrodes (2) adjacent to it in the electrode stack (S).

3. Electrode arrangement according to claim 1 or 2, characterized in that the support layer (3-1) of the first electrodes (1) and the support layer (3-2) of the second electrodes (2) are formed from a different support material and that the electrically conductive material (6-1) which is inserted between adjacent first electrodes (1) is the same or different from the support material of the first electrodes (1) and / or that the electrically conductive material (6-2) which is inserted between adjacent second electrodes (2) is the same or different from the support material of the second electrodes (2).

4. Electrode arrangement according to one of the preceding claims, characterized in that the support layer (3-1) of the first electrodes (1) is made of copper and / or that the support layer (3-2) of the second electrodes (2) is made of aluminum.

5. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6; 6-1, 6-2) is a plastically deformable material and in particular a pasty material at room temperature or at temperatures above room temperature.

6. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6; 6-1, 6-2) is plastically deformable and preferably has an elongation at break of more than 45% and a modulus of elasticity of less than 80 GPa.

7. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6; 6-1, 6-2) is a flat strip or a wire.

8. Electrode arrangement according to claim 7, characterized in that the electrically conductive material (6; 6-1, 6-2) is a flat band, wherein the flat band is flat or corrugated.

9. Electrode arrangement according to claim 7 or 8, wherein the flat strip is bent up in a C-shape or folded over at least once or several times along a fold line in the longitudinal direction of the strip.

10. Electrode arrangement according to one of the preceding claims, characterized in that the contact sections (5-1) of the first electrodes (1) are electrically connected to a first connecting element (8-1) and the contact sections (5-2) of the second electrodes (2) are electrically connected to a second connecting element (8-2).

11. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6; 6-1, 6-2) is a metal paste, a solder material, in particular tin or a tin alloy, graphite, graphene, polyaniline or a metal from the group consisting of silver, gold, aluminium, lead or copper or a mixture or alloy of these metals.

12. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6-1, 6-2) is a hollow profile, in particular a tube or a hollow rectangular profile.

13. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6-1, 6-2) is formed at least partially from the material of the support layer (3) of the first electrodes (1) and / or the support layer (3) of the second electrodes (2).

14. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6-1) on a first side (a) of the electrode arrangement (A) is formed from the material of the support layer (3) of the first electrodes (1) and / or the electrically conductive material (6-2) on a second side (b) of the electrode arrangement is formed from the material of the support layer (3) of the second electrodes (2).

15. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6-1) is formed on a first side (a) of the electrode arrangement (A) by rolling, bending, crimping or folding the protruding edge section of the support layer (3) of the first electrodes (1) and / or that the electrically conductive material (6-2) is formed on a second side (a) of the electrode arrangement (A) by rolling, bending, crimping or folding the protruding edge section of the support layer (3) of the second electrodes (2).

16. Electrode arrangement according to one of the preceding claims, characterized in that the electrically conductive material (6-1) on a first side (a) of the electrode arrangement (A) is formed from the material of the support layer (3) of the first electrodes (1) and an electrically conductive filler material and / or that the electrically conductive material (6-1) on a second side (b) of the electrode arrangement (A) is formed from the material of the support layer (3) of the second electrodes (2) and an electrically conductive filler material.

17. Electrode arrangement according to one of the preceding claims, characterized in that a recess (9) for introducing an electrolyte is provided on a first side (a) of the electrode arrangement in the contact sections (5-1) of the first electrodes (1) and the electrically conductive material (6-1) introduced and / or that a recess (9) for introducing an electrolyte is provided on a second side (b) of the electrode arrangement in the contact sections (5-2) of the second electrodes (2) and the electrically conductive material (6-2) introduced.

18. Method for manufacturing an electrode arrangement for a battery cell, in particular for a lithium-ion battery cell, comprising the following steps: • Providing at least one first electrode (1), one second electrode (2), one electrically insulating first separator (7-1) and one electrically insulating second separator (7-2), wherein the first electrode (1) and the second electrode (2) each comprise an electrically conductive support layer (3) and a coating (4) of an active material on at least one side of the support layer (3), and an edge section of each support layer (3) is formed as a contact section (5; 5-1, 5-2) which is at least partially free of the coating (4), • Generating at least one electrode arrangement (A) by stacking or placing on top of each other the first electrode (1), the first separator (7-1), the second electrode (2) and the second separator (7-2), wherein the contact section (5-1) of the first electrode (1) projects on a first side (a) of the electrode arrangement (A) over the two separators (7-1, 7-2) and the second electrode (2) and the contact section (5-2) of the second electrode (2) projects on a second side (b) of the electrode arrangement (A) over the two separators (7-1, 7-2) and the first electrode (1), characterized in that when generating the at least one electrode arrangement (A) or each electrode arrangement (A), an electrically conductive material (6; 6-1, 6-2) is applied to the contact sections (5-1, 5-2) of the first electrode (1) and the second electrode (2).

19. Method according to claim 18, characterized in that several electrode arrangements (A) are stacked along a stacking direction (s) to form a prismatic electrode stack (S).

20. Method according to claim 18, characterized in that a web-shaped electrode arrangement (A) is prismatically folded or cylindrically rolled around a roller axis (Ra) to form an electrode roll (R).

21. Method according to claim 18, characterized in that the separators (7; 7-1, 7-2) are formed from a strip of an electrically insulating, flexible material by zig-zag folding of the strip around fold edges (K) perpendicular to a stacking direction (r) and are stacked to form a Z-stack (Z) with successive layers of the separators (7; 7-1, 7-2), wherein a first electrode (1) and a second electrode (2) in the form of flat blanks are alternately placed between successive layers of the separators (7; 7-1, 7-2) of the Z-stack (Z) in the stacking direction (r).

22. Method according to claim 19, wherein when stacking the multiple electrode arrangements (A) to form the electrode stack (S), the contact sections (5-1) of the first electrodes (1) lying one above the other in the stacking direction (s) on the first side (a) of the electrode arrangement (A) and the contact sections (5-2) of the second electrodes (2) lying one above the other in the stacking direction (s) on the second side (b) of the electrode arrangement (A) are each arranged aligned one above the other, wherein on the first side (a) of the electrode arrangement (A) the electrically conductive material (6-1) is placed between the contact sections (5-1) of the first electrodes (1) lying adjacent to each other in the stacking direction (s) and the contact sections (5-1) of the first electrodes (1) lying adjacent to each other in the stacking direction (s) are electrically contacted with each other.and on the second side (b) of the electrode arrangement (A) between the contact sections (5-2) of the second electrodes (2) adjacent to each other in the stacking direction (s) the electrically conductive material (6-2) is located and the contact sections (5-2) of the second electrodes (2) adjacent to each other in the stacking direction (s) are electrically contacted with each other.

23. Method according to claim 20, wherein when winding up one electrode arrangement (A) to form an electrode roll (R), the contact sections (5-1) of the first electrode (1) on the first side (a) of the electrode arrangement (A) and the contact sections (5-2) The second electrode (2) on the second side (b) of the electrode arrangement (A) are arranged one above the other in the direction of the roller axis (Ra), wherein on the first side (a) of the electrode arrangement (A) the electrically conductive material (6-1, 6-2) is located between the contact sections (5-1) of the first electrode (1) of layers of the electrode roller (R) lying one above the other in a radial direction (r), and the contact sections (5-1) of the radially adjacent layers of the first electrode (1) are electrically contacted with each other, and on the second side (b) of the electrode arrangement (A) the electrically conductive material (6-1, 6-2) is located between the contact sections (5-2) of the second electrode (2) of layers of the electrode roller (R) lying one above the other in a radial direction (r).6-2) comes to rest and the contact sections (5-2) of the radially adjacent layers (r) of the second electrode (2) are electrically connected to each other.

24. Method according to claim 21, wherein, when inserting the first electrode (1) and the second electrode (2) between the successive layers of the separators (7-1, 7-2) of the Z-stack (Z), the contact sections (5-1) of the first electrodes (1) lying one above the other in the stacking direction (s) on the first side (a) of the electrode arrangement (A) and the contact sections (5-2) of the second electrodes (2) lying one above the other in the stacking direction (s) on the second side (b) of the electrode arrangement (A) are each arranged in alignment with one another, wherein on the first side (a) of the electrode arrangement (A) the electrically conductive material (6-1) is located between the contact sections (5-1) of the first electrodes (1) lying adjacent to each other in the stacking direction (s) and the contact sections (5-1) of the first electrodes (1) lying adjacent to each other in the stacking direction (s) are electrically contacted with each other,and on the second side (b) of the electrode arrangement (A) between the contact sections (5-2) of the second electrodes (2) which are adjacent to each other in the stacking direction (s) the electrically conductive material (6-2) comes to be located and the, Contact sections (5-2) of the second electrodes (2) lying adjacent to each other in the stacking direction (s) are electrically contacted with each other.

25. Method according to any one of claims 18 to 24, wherein the second side (b) of the electrode arrangement (A) is opposite the first side (a) of the electrode arrangement (A).

26. Method according to one of claims 18 to 25, characterized in that the electrically conductive material (6-1, 6-2) is fluid at temperatures above room temperature and / or is made fluid by the addition of a solvent.

27. Method according to one of claims 18 to 26, characterized in that the electrically conductive material (6-1, 6-2) is a flat strip, wherein the flat strip is bent up in a C-shape or folded over at least once or several times along a fold line along the longitudinal direction of the strip.

28. Method according to one of claims 18 to 16, characterized in that the electrically conductive material (6-1, 6-2) is a wire, wherein the wire is preferably rolled onto the contact sections (5-1, 5-2) of the first electrode (1) and the second electrode (2) when applied.

29. Method according to one of claims 18 to 28, characterized in that the electrically conductive material (6-1, 6-2) is designed as a hollow profile, in particular a tube or a hollow rectangular profile, wherein the hollow profile is preferably compressed when applied to the contact sections (5-1, 5-2) of the first electrode (1) and the second electrode (2).

30. Method according to one of claims 18 to 29, characterized in that the electrically conductive material (6-1, 6-2) is at least partially composed of the material of the support layer (3) of the first electrodes (1) and / or the support layer (3) of the second electrodes (2), wherein the electrically conductive material (6-1) is formed, in particular on the first side (a) of the electrode arrangement (A), by rolling, folding, bending or crimping the protruding edge section of the support layer (3) from the material of the support layer (3) of the first electrodes (1), and / or that the electrically conductive material (6-2) is formed, in particular on the second side (b) of the electrode arrangement (A), by rolling, folding, bending or crimping the protruding edge section of the support layer (3) from the material of the support layer (3) of the second electrodes (2).

31. Method according to one of claims 18 to 30, characterized in that the electrically conductive material (6-1, 6-2) is formed from the material of the support layer (3) of the first electrodes (1) and / or the support layer (3) of the second electrodes (2) and an electrically conductive filler material.

32. Method according to any one of claims 18 to 31, characterized in that the electrically conductive material (6-1) on the first side (a) of the electrode arrangement (A) is formed by rolling, bending, crimping or folding the protruding edge section of the support layer (3) of the first electrodes (1) and introducing an electrically conductive filler material into the rolled, bent, crimped or folded area of ​​the protruding edge section of the support layer (3) of the first electrodes (1) and / or that the electrically conductive material (6-2) on the second side (a) of the electrode arrangement (A) is formed by rolling, bending, crimping or folding the protruding edge section of the support layer (3) of the second electrodes (2) and introducing an electrically conductive filler material into the rolled, bent, crimped or folded area of ​​the protruding edge section of the support layer (3) of the second electrodes (2).

33. Method according to one of claims 18 to 32, characterized in that on the first side (a) of the electrode arrangement in the contact sections (5-1) of the first electrodes (1) and the introduced electrically conductive material (6-1) a recess (9) for the introduction of an electrolyte is provided and / or that on the second side (b) of the electrode arrangement in the contact sections (5-2) of the second electrodes (2) and the introduced electrically conductive material (6-2) a recess (9) for the introduction of an electrolyte is provided.

34. Battery cell (10) comprising a cell housing (11) and at least one electrode arrangement (A) housed therein according to one of claims 1 to 17 or at least one electrode arrangement (A) produced by the method according to one of claims 18 to 33.

35. Battery cell (10) according to claim 34, characterized in that the cell housing (11) contains at least two contacts, wherein a first contact (12-1) is electrically conductively connected to the contact sections (5-1) of the first electrodes (1) and the electrically conductive material (6-1) inserted between them, and a second contact (12-2) is electrically conductively connected to the contact sections (5-2) of the second electrodes (2) and the electrically conductive material (6-2) inserted between them.

36. Battery cell (10) according to claim 34 or 35, characterized in that the cell housing (11) is designed as a prismatic battery cell housing and comprises a base surface (G), a top surface (D) arranged parallel and at a distance from the base surface and at least four side surfaces (Fl, F2, F3, F4) which are each arranged between the base surface (G) and the top surface (D).

37. Battery cell (10) according to claim 36, characterized in that the cell housing (11) is composed of a first molded part (25) and a second molded part (20), wherein the first molded part (25) contains the base surface (G) and the top surface (D) as well as at least one of the side surfaces (F4), the second molded part (20) contains the remaining side surfaces (Fl, F2, F3) and the first molded part (25) is connected to the second molded part (20) by a joining connection.

38. Battery cell (10) according to claim 36 or 37, characterized in that the first molded part (25) is U-shaped and / or the second molded part (25) is U-shaped.

39. Battery cell (10) according to claim 37 or 38, characterized in that the second molded part (20) contains at least two contacts (12-1, 12-2) which are each configured for electrical contact with the terminal elements (8-1, 8-2) of the electrode arrangement (A).

40. Battery cell (10) according to one of claims 37 to 39, characterized in that the second molded part (20) has at least one filling opening (14) for introducing an electrolyte.

41. Battery cell (10) according to one of claims 37 to 40, characterized in that the second molded part (20) contains at least one burst membrane (13).

42. Battery cell (10) according to one of claims 37 to 41, characterized in that the first molded part (25) and / or the second molded part (25) contains grooves which fix the position of an electrode arrangement (A) arranged in the cell housing (11).

43. Battery cell (10) according to one of claims 37 to 42, characterized in that the first molded part (25) and the second molded part (25) are each formed from a sheet of metal by forming, in particular by bending or deep drawing.

44. Battery cell (10) according to claim 43, characterized in that the metal sheet is an aluminum sheet or a steel sheet and preferably has a thickness in the range of 0.1 mm to 1.0 mm.

45. Battery cell (10) according to one of claims 37 to 44, characterized in that the first molded part (25) is connected to the second molded part (20) by a circumferential weld seam (29), wherein the weld seam (29) is in particular along the free outer edges of the first molded part (25) and along the free outer edges of the second molded part (20).

46. ​​Battery cell according to one of claims 37 to 45, characterized in that, when assembling the battery cell, the contact sections (5-1, 5-2) of the electrode arrangement (A) are electrically connected to the contacts (12-1, 12-2) of the second molded part (20), then the first molded part (25) is brought into engagement with the second molded part (20), wherein by bringing the first molded part (25) into engagement with the second molded part (20) a closed battery cell housing is formed and the electrode arrangement (A) is completely surrounded by the closed battery cell housing, and the first molded part (25) is finally joined to the second molded part (20) by a joining connection, in particular by welding.

47. Battery cell according to one of claims 37 to 46, characterized in that the connecting elements (8-1, 8-2) of the electrode arrangement (A) are electrically conductively connected to the contacts (12-1, 12-2) arranged on the second molded part (20), wherein the electrically conductive connection is made in particular by means of laser welding or soldering.

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