Production of battery cells by tab extensions

Abstract

The invention relates to a method for producing a battery cell having at least two battery poles arranged on opposite sides, in which at least one electrode group is provided, the electrode group having a plurality of anode foils and cathode foils, the anode foils and the cathode foils being separated from one another by a separator foil, the anode foils having anode tabs at the ends thereof, and the cathode foils having cathode tabs at the ends thereof, the cathode foil has cathode tabs at the ends thereof, the anode tabs of the anode foil are bundled on a first side and the cathode tabs of the cathode foil are bundled on a second side of the electrode assembly, the bundled anode tabs and / or cathode tabs are electrically conductively connected to at least one tab extension at least in some regions, inserting at least one electrode group provided with at least one tab extension into the battery housing, the anode tab being electrically conductively connected directly or indirectly via the at least one tab extension to the current collector of the first battery post, the cathode tab is electrically conductively connected to the current collector of the second battery pole directly or indirectly via at least one tab extension, and wherein the battery housing is closed by the first battery pole and the second battery pole. The invention further relates to a battery cell.

Description

[0001] This invention relates to a method for producing a battery cell equipped with at least two battery terminals arranged on opposite sides, wherein at least one electrode assembly having multiple anode foils and cathode foils is placed in a battery casing, the anode foils and cathode foils being separated from each other by insulating foils. The invention also relates to a battery cell.

[0002] Besides so-called pouch cells with flexible or foil-like battery casings, hard-case batteries are also known. These battery cells have a rigid metal casing and can be geometrically prismatic or circular. Corresponding battery terminals are externally positioned as protrusions at the so-called terminals of the battery cell to facilitate simplified electrical connections. The battery terminals are typically integrated into the battery cell's cover, which encloses the internal volume of the battery casing.

[0003] The battery cover of a single battery cell is typically made of metal, such as aluminum, stainless steel, or steel with a nickel coating. Battery terminals are inserted insulated from the battery cover and are connected to the current collector. The battery terminals form an external electrical connection and are also electrically connected to the current collector, which faces the internal volume of the battery casing.

[0004] In electrochemical energy storage systems, such as lithium-ion batteries, electrode assemblies are arranged within the internal volume of the battery casing. These electrode assemblies consist of alternating anode, cathode, and separator layers. These anode and cathode foils can be formed by winding or stacking and positioned within the internal volume of the battery casing for end-use by the user. As part of the battery cell manufacturing process, the corresponding anode and cathode foils must be connected to the battery terminals. For this purpose, anode tabs and cathode tabs serve as connecting lines between the battery terminals and the anode or cathode foil. On the cell side, the uncoated ends of the copper carrier foil of the anode foil and the aluminum carrier foil of the cathode foil, extending from the electrode assembly, are typically welded to two current collectors. To provide optimal tooling access for welding to the current collectors, the anode and cathode tabs must be designed with excess length. This excess length results in the use of electrodes with wide uncoated areas and increases material requirements and waste.

[0005] Electrodes are typically manufactured as continuous strips. The active coating on the carrier foil is compacted between pairs of rolls using a calender, and then stamped to form either an anode or cathode foil. Due to the required excess length, wide, uncoated areas of the carrier film are provided, which may be particularly susceptible to deformation during the calendering process.

[0006] Therefore, the object of the present invention is to create a method for manufacturing a battery cell, wherein material waste is reduced and the connection from the tab to the current collector is simplified. This object is achieved by the features specified in claim 1. Further advantageous embodiments of the invention are a part of the dependent claims.

[0007] According to one aspect of the present invention, a method for manufacturing a battery cell is provided, the battery cell having at least two battery terminals arranged on opposite sides. The battery terminals may point or be oriented in two opposite directions.

[0008] In one step, at least one electrode assembly is provided, having multiple anode foils and cathode foils separated from each other by insulating foils. This at least one electrode assembly can be designed to be folded or stacked. In other words, the anode foils, cathode foils, and insulating foils can be cut into shape, placed on top of each other, or provided as long strips wound together.

[0009] The anode foil has an anode tab at one end, and the cathode foil has a cathode tab at one end. The anode and cathode tabs may protrude from the edges of the cut or wound anode and cathode foils. Advantageously, the anode tabs of the anode foil are bundled or aligned on a first side, and the cathode tabs of the cathode foil are bundled or aligned on a second side of the electrode assembly.

[0010] In a further step, the bundled anode and / or cathode tabs are electrically connected at least partially to at least one tab extension. Only the anode tabs, only the cathode tabs, or both the anode and cathode tabs may be extended by one or more tab extensions. The anode or cathode tabs may be in the form of a so-called flag-shaped tab assembly and can be flexibly extended as needed via tab extensions or busbars welded to the edges of the anode or cathode tabs of the electrode assembly, forming a connection with the current collector of the first and / or second battery terminals. This measure can reduce waste of carrier foil material used to form sufficiently long anode and / or cathode tabs. This also improves the manufacturability of the anode foil and / or cathode tabs, as the anode and / or cathode tabs to be formed in the form of uncoated carrier foil material can be designed to be shorter to minimize material deformation during the manufacture of the anode foil and / or cathode tabs.

[0011] At least one electrode assembly with at least one tab extension is placed into the battery casing. According to an embodiment, this step can be performed after connecting the first battery terminal or after connecting the second battery terminal.

[0012] The anode tab is electrically connected to the current collector of the first battery terminal directly (i.e., without tab extension) or indirectly via or using at least one tab extension, and the cathode tab is electrically connected to the current collector of the second battery terminal directly (i.e., without tab extension) or indirectly via at least one tab extension.

[0013] In a further step, the battery casing is sealed via a first battery terminal and a second battery terminal. For this purpose, the battery casing may have openings on two opposite sides to form a receiving space for at least one electrode assembly. The two open opposite sides or openings of the battery casing may be closed by the battery terminals after at least one electrode assembly has been inserted.

[0014] Preferably, the tab extension and / or at least one current collector has at least one alignment aid for aligning the tab extension with the current collector of the first battery terminal and / or the current collector of the second battery terminal. Therefore, one or more current collectors of a single battery cell may have alignment aids. As an alternative or supplement to the alignment aids arranged on the tab extension, each current collector may also have an alignment aid on its current collector side, which may correspond to or interact with the alignment aids on the tab side. The alignment aids on the tab side may also be designed as edge segments or edges of the tab extension. For example, the tab extension directly or indirectly connected to the anode tab and / or cathode tab can be positioned on the current collector of the first battery terminal and / or the current collector of the second battery terminal by means of the alignment aid. The alignment aid can be used to align the tab extension particularly precisely on the current collector. In a subsequent step, the tab extension aligned with the current collector can be connected to the current collector. This can be done, for example, by brazing or fusion welding. For example, the tab extension can be directly brazed or fused to the alignment aid to form a conductive connection.

[0015] The order of steps in the method according to the invention is not limited or fixed. In particular, certain process steps can be performed in any order.

[0016] For example, the first battery terminal can first be connected to the anode tab via a corresponding current collector and folded, then the electrode assembly with the first battery terminal is pushed into the battery housing, wherein the first battery terminal closes the first opening of the battery housing. Finally, the second battery terminal can be connected directly or indirectly to the second battery terminal using a tab extension. Folding the second battery terminal closes the second opening of the battery housing.

[0017] Alternatively or additionally, the at least one electrode assembly may be pushed into the battery housing before or after connecting at least one tab extension, and then electrically coupled to both battery terminals simultaneously or sequentially. The battery housing may be closed after the battery terminals are subsequently folded.

[0018] Advantageously, if the tab extension is connected to the anode or cathode tab, the connection to the current collector is made indirectly via the tab extension. If, for example, no tab extension is used on the tab, the connection to the corresponding current collector can be achieved directly or immediately. At least one tab extension can be used on at least one side of the electrode assembly.

[0019] The electrolyte solution for the battery cell can be filled before or after the battery casing is sealed. The battery casing can be sealed in a fluid-tight manner. For this purpose, the battery terminals can be designed as battery caps or battery caps that insert into openings in the sealed battery casing. The battery terminals or battery caps can be pressed into and / or welded to the battery casing to make the housing space of the battery casing fluid-tight. In order to fill the battery casing with electrolyte, according to embodiments, filling openings can be provided in the battery casing, in at least one battery cap, and / or on at least one battery terminal.

[0020] According to another aspect of the invention, a battery cell is provided having at least one electrode assembly with a plurality of anode foils and cathode foils. The anode foils and cathode foils are separated from each other by a separator foil. An anode tab is provided on a first side of the anode foil, and a cathode tab is provided on a second side of the cathode foil; these tabs may be designed, at least in partial areas, as stripped or uncoated sections of a carrier foil. The entire electrode assembly is arranged within a battery housing. The anode tabs are electrically connected directly, or without tab extensions, or indirectly via tab extensions to a current collector of a first battery terminal, and / or the cathode tabs are electrically connected directly, or without tab extensions, or indirectly via tab extensions to a current collector of a second battery terminal. The first and second battery terminals are configured to enclose the ends of the battery housing.

[0021] According to the design, the battery cell can have a liquid electrolyte solution, and the containment space of the battery casing is filled with the solution.

[0022] In addition, the battery terminals form an electrical connection to the anode and cathode foils of the electrode assembly so that the battery cells can be charged and discharged.

[0023] According to an example embodiment, at least one tab extension is provided by a solid material or by multiple material layers that are connected or not connected to each other in certain regions to extend the anode tab and / or cathode tab. The tab extension may be, for example, in the form of a busbar or a current-conducting film. The tab extension may be made of metal or a metal alloy, such as copper or aluminum.

[0024] According to the design, the tab extension may have an electrically insulating layer or be coated with an electrically insulating layer in at least a portion of its area to avoid conductive contact with the battery terminals or battery casing. The electrically insulating layer may take the form of paint or coating, or a flexible or shrinkable sheath.

[0025] The tab extension can advantageously be made of the same material as the tab. For example, the material used to connect the anode tab can be copper, and the material used to connect the cathode tab can be aluminum.

[0026] Furthermore, the at least one tab extension may also substantially have a tab cross-section for conducting current, which corresponds to the tab cross-section of the corresponding connected tab. The tab cross-section of the tab extension can be set by the material thickness and width of the tab extension. This allows for the setting of a constant resistivity that does not change between the current collector and the electrode assembly.

[0027] The tab extension made of solid material can be made of soft or flexible solid material. For example, the tab extension used to extend the anode tab can be made of copper material that has been soft-annealed and not chilled, so that the tab extension can be bent with very little force.

[0028] If at least one tab extension is formed of multiple material layers in a region of at least one bend point, and these material layers are not connected to each other at least in the bend point region, then at least one tab extension can be designed to be particularly flexible at least in certain areas. Therefore, the tab extension can be made of a laminated material having a single thin material foil. Thus, the tab extension can be folded with less force and at a smaller radius, which can save installation space.

[0029] In a particularly advantageous design of the tab extension, it can be partially (especially in the region of the bend) or entirely composed of a single layer of metal foil to selectively introduce localized bends. These bends enable repeatable folding of the tab extension and the tab itself. Regions of the tab extension can be provided with mechanically interconnected layers of material or metal foil to define non-foldable areas.

[0030] When multiple material layers of the tab extension are folded, these material layers are at least partially disconnected from each other; they can slide past each other, unfold, or move away from each other, thereby achieving a smaller bending radius and minimizing material load during bending.

[0031] According to a further embodiment, the anode tabs and / or cathode tabs are bundled centered or off-center along the width direction of the battery cell. This allows the tabs to be optimally prepared for folding during further assembly of the battery cell. For example, based on the bundled position, the desired bending radius can be limited or set when folding the tabs with tab extensions. Off-center or edge bundling of the tabs can allow for further bending or folding using the entire width of the battery casing after a 90° bend. This increases design freedom and provides compensation options for length variations of the tabs and tab extensions, such as due to thermal or mechanical factors.

[0032] Further connection of the tabs can be simplified if bundled anode and / or cathode tabs are assembled into a stack and secured in a bundled form by connecting them to at least one tab extension and / or by inserting at least one connecting seam. For example, the tabs can be assembled by material fitting, or by clamping or form fitting. Assembled tabs can create conductive connections between individual tabs or carrier foils, or mechanically couple them together in an insulating manner, at least in partial areas.

[0033] The conductive connection from the tab (e.g., by fusion welding or brazing) to the current collector can be made outside the battery housing to ensure optimal tooling access, such as for introducing the laser beam and clamping device during laser welding. Depending on the design, tooling access can be provided for the ultrasonic welding electrode and the corresponding anvil to enable ultrasonic welding of the tab to the current collector and / or the tab extension.

[0034] Since the assembled tabs (with or without tab extensions) are initially parallel to the base plane of the electrode assembly, and in the finished battery cell, the current collector is typically aligned perpendicular to this base plane for installation space reasons, the tabs must be folded during battery cell assembly. This may require excess length of the anode tab, at least in some areas, to allow for tool passage. Longer tabs can be arranged in a loop or folded during assembly. This excess length can be particularly advantageously provided by at least one tab extension, which provides optimal tool passage even without an excessively long carrier film layer.

[0035] If the bundled anode tabs and / or cathode tabs are electrically connected in at least a portion of their area to at least one foil-shaped, plate-shaped, or pre-bent tab extension, a tool channel for connecting a current collector to the tabs can be made particularly flexible.

[0036] According to a further embodiment, the at least one pre-bent tab extension is bent or folded into an arc, S-shape, or U-shape before being electrically connected to the anode tab and / or cathode tab. This measure allows the tab extension to be pre-bent and, when connected to the anode tab and / or cathode tab, to be bent to a flattened shape, at least in a partial area, for example by a clamping device. This bending is advantageously elastic.

[0037] Therefore, according to an advantageous embodiment, the at least one pre-bent tab extension undergoes elastic flattening deformation at least in a partial area to form an electrical connection with the current collector. In the first step, the tab extension can be elastically flattened or compressed by a clamping device. After the tab extension is connected to the anode tab and / or cathode tab, the clamping device can be released or removed, allowing the tab extension to return to its pre-bent shape. This minimizes the force required to bend or fold the tab and / or tab extension, which also reduces the risk of damaging the electrode assembly during cell assembly.

[0038] According to a further embodiment, at least two adjacent electrode groups are provided, whereby the bundled anode tabs and / or cathode tabs of the first and second electrode groups are electrically connected to at least one tab extension in at least a portion of the bundle. This measure allows the tabs of the two electrode groups to be coupled to the tab extension through a common connection seam.

[0039] In an alternative embodiment, the anode tabs of the first electrode group are offsetly connected to the anode tabs of the second electrode group along at least one spatial direction, or are connected to the anode tabs of the second electrode group by means of tab extensions overlapping each other. This can reduce the thickness of the tabs and tab extensions to be welded, thereby achieving a more reliable weld.

[0040] Alternatively or additionally, the cathode tabs of the first electrode group are offsetly connected to the cathode tabs of the second electrode group along at least one spatial direction, or are connected to the cathode tabs of the second electrode group by means of tab extensions overlapping each other. This measure allows for greater freedom in terms of connection with the tab extensions. In particular, the shaped tabs of different electrode groups can also be formed to overlap or offset each other, which can be advantageously used to insert multiple connecting seams to establish a conductive connection between the tabs and the tab extensions.

[0041] If the tab extension for the anode tab is provided with a material composition of the anode tab, and the tab extension for the cathode tab is provided with a material composition of the cathode tab, the tab extension can be connected to at least one tab in a particularly robust manner by fusion welding or brazing. If the tab extension is made of, for example, the material of a studded flag-shaped tab assembly or a bundle of tabs, the tab extension can be reliably and uniformly connected. According to embodiments, the tab extension may have a thickness or material thickness corresponding to the thickness or material thickness of the tab (i.e., the anode tab and / or the cathode tab).

[0042] According to a further embodiment, the anode tab and / or cathode tab and / or at least one tab extension are aligned parallel to the surface of at least one current collector and pressed against the current collector for electrical connection. This measure provides an optimal tooling path for connections where the insert materials mate. The surfaces to be connected can be pressed against each other, for example, by a clamping device.

[0043] According to a further embodiment, after electrical connection, the first battery terminal and / or the second battery terminal are folded toward the battery housing, particularly at a 90° angle, to close the battery housing. After insertion of the conductive connection, the tabs and / or tab extensions may be bent and / or folded to close the opening in the battery housing via the battery terminal or via a battery cap in which the battery terminal is inserted.

[0044] According to a further embodiment, at least one tab extension is elastically and / or plastically deformed before and / or during folding of the battery terminal. This minimizes the space required within the battery housing for the tab extension. In addition to dynamic length compensation for the electrical connection between the electrode assembly and the current collector, the elastic deformation of the tab extension also enables a spring force that secures or supports the electrode assembly relative to the current collector or the corresponding battery cover.

[0045] According to a further embodiment, the at least one alignment aid is designed as at least one centering hole configured to interact with at least one pin and / or protrusion of the current collector. At least one tab extension positioned on the current collector is connected to the current collector material at and / or at a location spaced apart from the alignment aid. This allows the tab-side alignment aid to couple to the current collector-side alignment aid. A conductive connection between the tab extension and the current collector can be made via the alignment aid. Alternatively or additionally, the electrical connection can be achieved, for example, by edge welding or brazing along one edge of the tab extension.

[0046] According to a further embodiment, the tab extension is positioned at an angle relative to a first side of at least one electrode group. Then, the anode tab of the first electrode group is electrically connected to the tab extension. In a further step, the tab extension is positioned relative to the first side at a first angle or a second angle and connected to the anode tab of the second electrode group.

[0047] According to a further alternative or additional embodiment, the tab extension is positioned at a first angle relative to the second side. Then, the cathode tab of the first electrode group is conductively connected to the tab extension. Furthermore, the tab extension is positioned relative to the second side at a first or second angle and connected to the cathode tab of the second electrode group. Then, the tab extension is rotated relative to the second side at a second or third angle and positioned on the current collector of the second battery terminal and connected to the current collector of the second battery terminal.

[0048] The first electrode group and the second electrode group can form a common first side and / or second side, which can serve as a reference for the angle of the tab extension. For example, the first side can be designed as a straight line extending along the width and / or height direction, and the tab extension can be positioned at an angle relative to this straight line to provide a simplified tooling path. The tab extension is also rotated and positioned or aligned with the current collector of the first battery terminal at a second or third angle relative to the first side, and then connected to the current collector. Setting different angles enables specially optimized tooling paths for inserting welded or clamped connections between the tab and the tab extension, and between the tab extension and the current collector. The tab extension can have a pre-bent shape, for example, to accommodate the tab at the edge and minimize the space required inside the battery housing.

[0049] The electrode extension can be arranged relative to the electrode and the current collector, and the angle can be adjusted using a holding device or clamp.

[0050] According to an embodiment, all the tabs of multiple electrode groups can be arranged together on a first side of the tab extension, or together on a second side of the tab extension, and electrically connected to the tab extension. Alternatively, one tab can be arranged on the first side of the tab extension, and at least one additional tab can be arranged on the second side of the tab extension and connected to it. In this way, a tab designed as an anode or cathode tab can be connected to the front or back of the tab extension.

[0051] Several embodiments of the invention will now be explained in more detail with reference to the accompanying drawings. They illustrate:

[0052] Figure 1 A three-dimensional view of the stacked electrode assembly is shown.

[0053] Figure 2 It shows Figure 1 A three-dimensional diagram of an electrode assembly with bundled tabs.

[0054] Figure 3 A detailed view of the bundled anode tabs and the connected tab extensions is shown.

[0055] Figure 4 A perspective view of the process steps according to an embodiment of the present invention is shown, wherein an electrode assembly is inserted into a battery casing.

[0056] Figure 5 The diagram shows a side cross-sectional view illustrating the indirect coupling of the anode tab to the current collector via the tab extension.

[0057] Figure 6 This illustration shows a side cross-sectional view illustrating the folding of the tab extension when the battery casing is closed, according to an example embodiment.

[0058] Figure 7 A side cross-sectional view of the tab extension according to another embodiment is shown.

[0059] Figure 8 A perspective view of a battery cell produced by the method according to the present invention is shown, according to an embodiment of the present invention.

[0060] Figure 9 A side cross-sectional view is shown to illustrate a method for producing a battery cell according to another embodiment of the present invention.

[0061] In the accompanying drawings, the same reference numerals denote the same elements or structural components. The size and relative positions of the elements in the drawings are not necessarily drawn to scale, and some of these elements are enlarged and positioned for clarity. Furthermore, the specific shapes of the elements drawn are not intended to convey any information about the actual shape of the individual elements, but are chosen solely for ease of identification in the accompanying drawings.

[0062] The accompanying drawings illustrate a method for manufacturing a battery cell 100 according to the present invention, the battery cell being equipped with at least two battery terminals 101, 102 arranged on opposite sides. In the illustrated embodiment, the battery terminals 101, 102 point in two opposite directions or are located on opposite narrow sides. The method is described using the manufacture of a battery cell 100 designed as a prismatic hard-shell cell as an example.

[0063] Figure 1 A perspective view of an electrode assembly 10 arranged in a stacked configuration is shown. For clarity, only one electrode assembly 10 is provided. However, the method is not limited to a single electrode assembly 10. In particular, two or more electrode assemblies 10 may be provided arranged adjacent to each other.

[0064] Figure 1 The steps of the method are illustrated, wherein at least one electrode assembly 10 is provided, the electrode assembly having a plurality of anode foils 11 and cathode foils 12, which are separated from each other by insulating foils 13. Exemplarily, the at least one electrode assembly is designed in a stacked form. This means that the anode foils 11, cathode foils 12 and insulating foils 13 are cut into rectangular shapes and placed on top of each other.

[0065] The anode foil 11 has an anode tab 21 at its end, and the cathode foil 12 has a cathode tab 22 at its end. The anode tab 21 and cathode tab 22 protrude from the cut edges of the anode foil 11 and cathode foil 12. The anode tab 21 of the anode foil 11 protrudes from a first side S1 of the electrode assembly 10, and the cathode tab 22 of the cathode foil 12 protrudes from a second side S2 of the electrode assembly 10. As a result, the anode tab 21 and cathode foil 12 are arranged in such a way that the anode tab 21 and cathode tab 22 are aligned.

[0066] Figure 2 It shows Figure 1 A perspective view of an electrode assembly having bundled tabs 21 and 22. For clarity, the terms tabs 21 and 22 can be understood to refer to the use of anode tab 21 and / or cathode tab 22. Figure 2 Further steps of the method according to the invention are shown, wherein the anode tabs 21 of the anode foil 11, designed as a so-called copper flag, are first centered along the width direction B or relative to the electrode assembly 10, and then stapled or bundled. Similar to the first side S1, the cathode tabs 22 of the cathode foil, designed as an aluminum flag, are placed on the edge of the electrode assembly 10 on the second side S2 and are also stapled.

[0067] The anode tab 21 and the cathode tab 22 are pinned together or bundled to form bundled anode tabs 21' and bundled cathode tabs 22', for example, by ultrasonic welding using an anvil and ultrasonic welding electrode (not shown).

[0068] Figure 2 Also shown is the use of tab extensions 23 on bundled anode tabs 21'. The tab extensions 23 shown are exemplary made of a solid material and have a material composition corresponding to the material composition of the bundled anode tabs 21'. Thus, in the illustrated example embodiment, the tab extensions 23 are composed entirely of copper or a copper alloy.

[0069] exist Figure 2 In the middle, the tab extension 23 is only guided to the bundled anode tabs 21'.

[0070] Figure 3 A detailed view of a bundle of anode tabs 21' with tab extensions 23 connected by laser welding is shown. As an example, only the bundle of anode tabs 21' is extended along the length direction L of the cell 100 or electrode group 10 by the tab extensions 23.

[0071] By laser welding, two connecting seams V are inserted through the bundled anode tabs 21' into the tab extension 23 to create a material-fitting connection. The connecting seams V are offset parallel to each other along the height direction H and along the length direction L. The tab extension 23 is connected to the edge of the bundled anode tabs 21' and forms a conductive extension of the bundled anode tabs 21'.

[0072] Then, at least one electrode assembly 10 with at least one tab extension 23 is inserted into the battery housing 30. This step is performed, for example, after the second battery terminal 102 is connected to the bundled cathode tabs 22'. For this purpose, the bundled cathode tabs 22' are electrically connected to a current collector (not shown), which is electrically coupled to the second battery terminal 102. The second battery terminal 102 is exemplary designed as a positive terminal and is tilted 90° after welding so that the battery housing 30 can be closed on one side.

[0073] exist Figure 4 The diagram shows a perspective view illustrating method steps according to an embodiment of the invention, wherein an electrode assembly 10 is inserted into a battery housing 30. As an example, the electrode assembly 10 is inserted into the battery housing 30 with the tab extension 23 as a guide. This can be done with or without aids such as foil or insertion tools.

[0074] In the illustrated embodiment example, the battery housing 30 is designed as an extruded profile made of aluminum alloy, and has a first opening 31 on a first side S1 and a second opening 32 on a second side S2.

[0075] The electrode assembly 10 is pushed into the internal volume 33 of the battery housing 30 through the second opening 32 until the second battery terminal 102 closes the second opening 32. Movement along the longitudinal direction L is indicated by the arrow shown. At the first opening 31 opposite the second opening 32, the tab extension 23 can protrude, thereby enabling an optimal tool passage for conductively connecting the tab extension 23 to the current collector 111 of the first battery terminal 101.

[0076] Figure 5 The side cross-sectional view shows the indirect coupling of the anode tab 21' to the current collector 111 via the tab extension 23. For this purpose, the first battery terminal 101, which is inserted into the first battery cover 121 and electrically insulated relative to the battery cover 121 by the insulator 130, is guided to the tab extension 23.

[0077] In a further step, the tab extension 23 is welded to the current collector 111 of the first battery cover 121. The first battery terminal 101, located on the side of the battery cover 121 opposite to the current collector 111, is designed as a negative terminal in the illustrated embodiment example.

[0078] By connecting the tab extension 23 to the current collector 111, the bundled anode tabs 21' are indirectly electrically connected to the current collector 111 and the first battery terminal 101. This is accomplished by inserting the connection point V (e.g., by laser welding).

[0079] In a subsequent step, the battery cover 121 can be folded 90°, thereby folding and / or bending the bundled anode tabs 21' and tab extensions 23. This occurs, for example, within the internal volume 33 of the battery housing 30, and... Figure 6 The figure is shown in a side view section.

[0080] Figure 6 The steps of the method according to the invention are further illustrated, wherein the first opening 31 of the battery housing 30 is closed by the first battery cover 121 or the first battery terminal 101.

[0081] By closing the first opening 31 with the first battery terminal 101, the distance between the current collector 111 and the electrode group 10 along the length direction L is reduced, such that in addition to the bundled anode tabs 21', the tab extension 23 is also folded and / or bent in at least one bending region B.

[0082] Similar to Figure 6 , Figure 7 A side sectional view is shown to illustrate the tab extension 24 according to yet another embodiment. Figure 6 Compared to the solid material form of the tab extension 23 shown, in Figure 7 The laminated tab extension 24 is used.

[0083] The laminated tab extension 24 consists of a plurality of material layers 25 that are connected to each other at least in a partial area. In the illustrated embodiment example, the material layers 25 are connected to each other at connection points V on the edge side.

[0084] Each material layer 25 is exemplarily designed as a thin copper foil, thereby allowing the tab extension 24 to be folded with very little force and at a small radius. This makes it possible to minimize the installation space required for the tab extension 24.

[0085] After the first battery cover 121 is pressed into the first opening 31 of the battery housing 30, the battery housing 30 is completely sealed. Exemplarily, after the battery housing 30 is sealed, an electrolyte solution can be injected into the internal volume 33 of the battery housing via a filling opening (not shown). In this way, the battery cell 100 is completed in the illustrated embodiment example.

[0086] Figure 8 A perspective view of a battery cell 100 produced by the method according to an embodiment of the present invention is shown. The battery cell 100 is in the form of a prismatic hard-shell cell.

[0087] The battery cell 100 essentially includes a battery casing 30, which has at least one electrode assembly 10 within an internal volume 33. The anode foil 11 of the electrode assembly 10 is electrically connected to a first battery terminal 101. The cathode foil 12 of the electrode assembly 10 is electrically connected to a second battery terminal 102.

[0088] exist Figure 9 The image shows a side cross-sectional view to illustrate a method for producing a battery cell 100 according to yet another embodiment of the invention. Here, the attachment of the tab extension 23 to the first side S1 is shown.

[0089] This embodiment of the method differs from the methods described to date in that the tab extensions 23 are arranged at different angles α to provide an optimal tool path for inserting the conductive connection V. Furthermore, two electrode groups 10.1 and 10.2 are provided, each having bundled anode tabs 21.1' and 21.2'. Both anode tabs 21.1' and 21.2' are connected to the tab extensions 23.

[0090] The tab extension 23 is positioned at a first angle α1 relative to the first side S1 of the electrode groups 10.1, 10.2. The electrode stacks 10.1, 10.2 are arranged parallel to each other and are flush at the edges in the illustrated embodiment. The first angle α1 is, for example, 55°, and allows the laser weld seam V to be introduced into the overlapping area between the tab extension 23 and the anode tabs 21.1', 21.2'.

[0091] The tab extension 23 can be arranged relative to the anode tabs 21.1', 21.2' and the current collector 111 by means of the holding device 40 or the clamp, and can be adjusted by an angle α.

[0092] For example, the anode tab 21.1' of the first electrode group 10.1 is conductively coupled to the first side 23.1 of the tab extension 23, and the anode tab 21.2' of the second electrode group 10.2 is conductively coupled to the second side 23.2 of the tab extension 23. To achieve a flush or flat connection between the tab extension 23 and the current collector 111, the tab extension 23 is pre-bent. The tab extension 23 has an S-shape, which provides a space for accommodating the bundled anode tabs 21.2' between the second side 23.2 of the tab extension 23 and the current collector 111.

[0093] After the anode tabs 21.1' and 21.2' are connected to the tab extension 23, the electrode assemblies 10.1 and 10.2 are pushed into the battery housing 30. The battery terminal 101 is then electrically connected to the tab extension 23. For this purpose, the tab extension 23, with the connected anode tabs 21.1' and 21.2', is secured by a clamp 40 to ensure the tool channel for inserting the conductive connection V. Figure 9 Arrow V in the diagram illustrates an example of the tool channel of a laser welding device.

[0094] To facilitate the alignment of the tab extension 23 with the current collector 111, an alignment aid 26 is provided on the tab side. The tab-side alignment aid 26 can interact with the current collector-side alignment aid. For clarity, the current collector-side alignment aid is not shown. In the illustrated embodiment, the tab-side alignment aid 26 is designed as one or more through holes. The current collector-side alignment aid can be designed as a pin or a protrusion corresponding to the through holes.

[0095] According to the design, in order to accurately position the tab extension 23 on the current collector 111, the tab extension 23 can be pushed against the edge of the alignment aid on the current collector side. Therefore, the edge section or edge of the tab extension 23 can also be used as the alignment aid 26 on the tab side. The corresponding alignment aid on the current collector side can be in the form of a protrusion / bulge or a back punch, a pin, etc., against which the tab extension 23 can be pushed.

[0096] Therefore, the alignment aid 26 on the current collector side and / or the alignment aid 26 on the tab side can be used as an end stop and restrict the degree of freedom of movement of the tab extension 23 in at least one spatial direction.

[0097] To connect both anode tabs 21.1' and 21.2' to the tab extension 23, the first angle α1 remains unchanged. To connect the tab extension 23 to the current collector 111, the clamp 40 can be set to a second angle α2, for example, 30°. The tab extension 23 can be connected to the current collector 111, for example, by brazing or fusion welding. For example, the tab extension 23 can be directly fusion welded or brazed to the alignment aid 26 to form a conductive connection. As an example, the conductive connection between the tab extension 23 and the current collector 111 is formed at a distance from the alignment aid 26, in the form of an overlapping seam at the edge section of the tab extension 23.

[0098] The battery terminal 101 with current collector 111 can then be rotated to 0° at one end to close the battery casing 30.

[0099] The process is illustrated exemplarily using the first side S1 of the battery cell 100. Similarly, the method can be implemented on the second side S2 of the battery cell 100 using a cathode tab 22.

Claims

1. A method for producing a battery cell (100), said battery cell (100) having at least two battery terminals (101, 102) arranged on opposite sides (S1, S2), wherein At least one electrode assembly (10) is provided having a plurality of anode foils (11) and cathode foils (12), the anode foils (11) and cathode foils (12) being separated from each other by a separator foil (13), wherein the anode foils (11) have anode tabs (21) at their ends, and the cathode foils (12) have cathode tabs (22) at their ends, the anode tabs (21) of the anode foils (11) being bundled on a first side (S1) of the electrode assembly (10), and the cathode tabs (22) of the cathode foils (12) being bundled on a second side (S2) of the electrode assembly (10). - The anode tab (21) and / or cathode tab (22) are electrically connected to at least one tab extension (23) in at least a portion of their respective regions. - Insert at least one electrode assembly (10) having at least one tab extension (23) into the battery casing (30). - The anode tab (21) is electrically connected directly to the current collector (111) of the first battery terminal (101) without the tab extension (23), or indirectly to the current collector (111) of the first battery terminal (101) via the at least one tab extension (23), and the cathode tab (22) is electrically connected directly to the current collector of the second battery terminal (102) without the tab extension (23), or indirectly to the current collector of the second battery terminal (102) via the at least one tab extension (23). - The battery casing (30) is enclosed by the first battery terminal (101) and the second battery terminal (102). Its features are, The tab extension (23) and / or at least one current collector (111) have at least one alignment aid (26) for aligning the tab extension (23) with the current collector (111) of the first battery terminal (101) and / or the current collector of the second battery terminal (102), wherein the tab extension (23) directly or indirectly connected to the anode tab (21) and / or the cathode tab (22) is positioned on the current collector (111) of the first battery terminal (101) and / or the current collector of the second battery terminal (102) by means of the alignment aid (26).

2. The method according to claim 1, wherein, At least one tab extension (23, 24) is provided by a solid material or by a plurality of material layers (25), which are connected or not connected to each other at least in a portion of the area to extend the anode tab (21) and / or the cathode tab (22).

3. The method according to claim 2, wherein, At least one tab extension (24) is formed in the region of at least one bend (B) by a plurality of material layers (25) that are not connected in the region of the bend (B).

4. The method according to any one of claims 1 to 3, wherein, The anode tabs (21) and / or the cathode tabs (22) are bundled together centered or off-center along the width direction (B) of the battery cell (100).

5. The method according to any one of claims 1 to 4, wherein, Bundles of anode tabs (21') and / or bundles of cathode tabs (22') are assembled into a stack and secured in a bundled form by connecting to at least one tab extension (23) and / or by introducing at least one connection point (V).

6. The method according to any one of claims 1 to 5, wherein, Bundles of anode tabs (21') and / or bundles of cathode tabs (22') are electrically connected in at least a portion of their area to at least one foil-shaped or plate-shaped and / or pre-bent tab extension (24).

7. The method according to claim 6, wherein, At least one pre-bent tab extension (23) is bent or folded into an arc, S-shape or U-shape before being electrically connected to the anode tab (21) and / or cathode tab (22), particularly by plastic deformation.

8. The method according to claim 6 or 7, wherein, At least one pre-bent tab extension (23) undergoes elastic flattening deformation in at least a portion of the area to form an electrical connection with the current collector (111).

9. The method according to any one of claims 1 to 8, wherein, At least two adjacent electrode groups (10) are provided, wherein the bundled anode tabs (21') and / or cathode tabs (22') of the first electrode group (10) and the second electrode group are electrically connected to at least one tab extension (23) in at least a portion of the region, wherein the anode tab (23) of the first electrode group (10) is connected to the anode tab of the second electrode group in an offset manner along at least one spatial direction (B, H, L) or is connected to the anode tab of the second electrode group in an overlapping manner by means of the tab extension (23), and / or wherein the cathode tab (22) of the first electrode group (10) is offset relative to the cathode tab of the second electrode group in at least one spatial direction (B, H, L) or is connected to the tab extension (23) in an overlapping manner.

10. The method according to any one of claims 1 to 9, wherein, The tab extension (23) for the anode tab (21) is provided by the material composition of the anode tab (21), and the tab extension (23) for the cathode tab (22) is provided by the material composition of the cathode tab (22).

11. The method according to any one of claims 1 to 10, wherein, The anode tab (21) and / or the cathode tab (22) and / or the at least one tab extension (23) are aligned parallel to the surface of at least one current collector (111) and pressed against the current collector (111) for electrical connection, wherein, after the electrical connection, the first battery terminal (101) and / or the second battery terminal (102) are folded toward the battery housing (30), particularly at an angle of 90°, to close the internal volume (33) of the battery housing (30).

12. The method according to claim 11, wherein, Before and / or during the folding of the battery terminals (101, 102), at least one tab extension (23) is elastically and / or plastically deformed.

13. The method according to claim 1, wherein, The at least one alignment aid (26) is configured as at least one through hole, the through hole being configured to engage with at least one pin and / or protrusion of the current collector (111), wherein the at least one tab extension (23) positioned on the current collector (111) is connected to the material of the current collector (111) at the alignment aid (26) and / or at a position spaced apart from the alignment aid (26).

14. The method according to any one of claims 9 to 13, wherein, The tab extension (23) is positioned at a first angle (α1) relative to the first side, and the anode tab (21') of the first electrode group (10) is electrically connected to the tab extension (23). The tab extension (23) is positioned at the first angle (α1) or the second angle (α2) relative to the first side and connected to the anode tab (21') of the second electrode group. The tab extension (23) is rotated and positioned at the current collector (111) of the first battery terminal (101) relative to the first side at the second angle (α2) or the third angle (α3) and connected to the current collector (111).

15. The method according to any one of claims 9 to 14, wherein, The tab extension (23) is positioned at a first angle (α1) relative to the second side, and the cathode tab (22') of the first electrode group (10) is electrically connected to the tab extension (23). The tab extension (23) is positioned at the first angle (α1) or the second angle (α2) relative to the second side and connected to the cathode tab (22') of the second electrode group. The tab extension (23) is rotated and positioned at the current collector of the second battery terminal (102) relative to the second side at the second angle (α2) or the third angle (α3) and connected to the current collector of the second battery terminal (102).

16. A battery cell (100) having at least one electrode assembly (10) having a plurality of anode foils (11) and cathode foils (12) separated from each other by a separator foil (13), wherein the anode foils (11) have anode tabs (21) on a first side (S1) and the cathode foils (12) have cathode tabs (22) on a second side (S2), and the anode foils (11) and cathode foils (12) are arranged in a battery housing (30), wherein the anode tabs (21) are directly electrically connected to a first battery terminal (101) without tab extensions (23). The current collector (111) of the first battery terminal (101) is electrically connected to the current collector (111) of the first battery terminal (101) via the tab extension (23), and / or the current collector (22) of the cathode terminal (102) is electrically connected directly to the current collector of the second battery terminal (102) without the tab extension (23), or indirectly to the current collector of the second battery terminal (102) via the tab extension (23), wherein the first battery terminal (101) and the second battery terminal (102) are configured to close the ends of the battery housing (30), and the tab extension (23) and / or at least one current collector (111) have at least one alignment aid (26), wherein, The tab extension (23) directly or indirectly connected to the anode tab (21) and / or cathode tab (22) is positioned on the current collector (111) of the first battery terminal (101) and / or the current collector of the second battery terminal (102) by means of the alignment aid (26).

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