Method for manufacturing prismatic battery single cells

Abstract

The present invention relates to a method for manufacturing a prismatic battery cell (2), wherein an electrode stack (16) is provided having a first electrode (6) and a second electrode (8) stacked vertically, wherein a conductor (10) of the first electrode (6) extends from the end side (18) of the electrode assembly (16) in the longitudinal direction (L), wherein the conductors (10) of the first electrode (6) are pressed together and welded together, particularly by ultrasonic welding, wherein the pressed conductors (10) are arranged on the flat side (24) of the contact element (26) forming the cell terminal of the cell cover (28) of the cell housing (30) and welded together with the contact element (26), particularly by laser welding, and wherein the cell cover (28) is arranged on the electrode stack (16), particularly pushed onto the electrode stack, such that the cell cover (50), particularly the side side (24), is parallel to the end side (18). Furthermore, the present invention relates to such a prismatic battery cell (2) and a motor vehicle having such a battery cell (2).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a prismatic battery cell, in which the conductor of the first electrode of the battery cell is pressed together and welded to a contact metal sheet. Furthermore, this invention relates to a prismatic battery cell manufactured according to the method. Background Technology

[0002] Electric motor vehicles typically have a traction battery (high-voltage battery, HV battery) that supplies energy to the electric motor used to drive the vehicle. Here, electric motor vehicles should be understood in particular as electric vehicles (BEVs, battery electric vehicles, or pure electric vehicles) that store the energy required for propulsion solely in the traction battery, range-extended electric vehicles (REEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and / or fuel cell electric vehicles (FCEVs), where fuel cell vehicles temporarily store the electrical energy generated by the fuel cell in the traction battery.

[0003] Such traction batteries typically consist of multiple battery cells, particularly lithium-ion battery cells, that are electrically connected in series and / or in parallel with each other.

[0004] Here, individual batteries are classified into different types or categories based on their design. For example, pouch-pack batteries (Coffee-Bag-Zelle) have a foil, particularly an aluminum composite foil, as the outer shell, within which the electrodes of the battery are enclosed. Conversely, cylindrical batteries include a relatively bend-resistant shell, particularly made of metal sheet, which is essentially cylindrical in shape. Furthermore, so-called prismatic batteries are known, whose shells are also constructed to be relatively bend-resistant, particularly made of metal sheet, and are essentially cuboid in shape.

[0005] A single-cell battery is known from DE 10 2021 114 887 A1. The single-cell battery includes a housing and a plurality of electrodes disposed therein, each electrode having at least one anode and at least one cathode. The housing has an outer casing portion having at least one open end side, wherein the end side is closed by a multi-layered cover element. A first layer made of conductive material is connected to either the anode or the cathode.

[0006] DE 10 2019 102 032 A1 relates to an energy storage single cell having a plurality of electrodes of a first polarity and a plurality of electrodes of a second polarity, wherein these electrodes are arranged in an electrode stack. Each of the first polarity electrodes has a first conductive tab protruding from a first side of the electrode stack, and each of the second polarity electrodes has a second conductive tab protruding from a second side of the electrode stack opposite to the first side. The electrode stack is disposed in a housing, which is electrically connected to the first conductive tab.

[0007] A method for manufacturing a component is described in DE 10 2021 108 104 A1, wherein the component has a plurality of single-pool foils stacked vertically and at least one contact metal sheet. The single-pool foils form a foil stack in a connecting section, and the foil stack is connected to the contact metal sheet by at least one weld. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a particularly suitable method for manufacturing prismatic battery cells. Furthermore, it aims to provide such a battery cell and an electrically driven motor vehicle having such a battery cell.

[0009] Regarding the method described above, according to the present invention, the aforementioned technical problem is solved by the features of claim 1. According to the present invention, in the case of a single battery cell, the aforementioned technical problem is solved using the features of claim 9, and in the case of a motor vehicle, the aforementioned technical problem is solved using the features of claim 10. Advantageous designs and extensions are the subject of the dependent claims. Here, the implementation of the method also applies to single battery cells, and vice versa.

[0010] The method is used to manufacture a prismatic battery cell. This prismatic battery cell is suitably constructed as a lithium-ion battery cell. Preferably, the battery cell is configured and set up as a traction battery for an electrically driven motor vehicle.

[0011] First, an electrode stack is provided, having first and second electrodes stacked vertically in a direction referred to here and below as the stacking direction or stacking height direction. That is, the electrode stack is formed by means of a plurality of first electrodes and a plurality of second electrodes, wherein these electrodes are arranged vertically in the stacking direction. Suitably, the first and second electrodes are arranged alternately, wherein a diaphragm is arranged between each of the first electrodes and their adjacent second electrodes.

[0012] For example, each first electrode is configured as an anode, and each second electrode is configured as a cathode.

[0013] Each electrode is constructed in a suitable manner as a sheet. Here, the corresponding electrode is formed by means of a foil-like substrate, particularly of a metal foil. The corresponding substrate includes a (first) section coated with an active material and, particularly, a conductor (Ableiter) formed on this section as a second section. This conductor is also referred to as a fähnchen. Suitably, the coated section of the substrate of each electrode has a rectangular base. Preferably, the base is not square; in other words, the rectangular base has different side lengths. In this electrode stack, the first section of the electrode is correspondingly stretched into a plane perpendicular to the stacking direction. Suitably, the conductor does not extend along the entire length of the corresponding side.

[0014] The conductor preferably extends from the short side of the first rectangular segment of the corresponding substrate.

[0015] In a suitable manner, in an electrode stack, the conductor of the first electrode extends a first segment away from the corresponding substrate in a direction perpendicular to the stacking direction, referred to as the longitudinal direction, and the conductor of the second electrode extends away from the first segment of the corresponding substrate in the opposite direction to the longitudinal direction. Therefore, the conductors of the first electrode are arranged in a vertically overlapping manner in the stacking direction, and the conductors of the second electrode are also arranged in a vertically overlapping manner in the stacking direction. Here, the conductor of the first electrode is arranged on one side of the electrode stack, referred to as the first end side, and the conductor of the second electrode is arranged on a second end side of the electrode stack opposite to the first end side; that is, the second end side is oriented parallel to the first end side and perpendicular to the stacking direction.

[0016] In summary, the conductor of the first electrode extends from the first end side of the electrode stack in the longitudinal direction, and the conductor of the second electrode extends from the second end side of the electrode stack opposite to the first end side in the opposite longitudinal direction. Here, the longitudinal direction is the direction along one edge of the substrate, particularly one of the long sides, from the second end side to the first end side.

[0017] According to the method, the conductors of the first electrode are pressed together and welded together. Here, pressing and welding can be performed sequentially in time. It is particularly preferred that the conductors of the first electrode be welded together by ultrasonic welding. Thus, pressing and welding are suitably performed simultaneously during the ultrasonic welding process. Preferably, an ultrasonic tool is used directly on the conductors. In other words, no protective element, particularly a protective foil or protective metal sheet, is used between the ultrasonic tool and the conductors and welded to the conductors.

[0018] Appropriately, the conductor pressed against the first electrode is then trimmed, i.e., cut, in particular truncated, so that the free ends of the conductors are flush with each other in the stacking direction.

[0019] Subsequently, the conductor (cut in a suitable manner) of the first electrode is welded to the conductive contact element of the single-cell cover of the single-cell housing. In particular, the conductor and the contact metal sheet are laser welded together. For this purpose, the pressed area of ​​the conductor is first arranged on the flat side of the contact element. In particular, the pressed area of ​​the conductor is preferably placed directly, i.e., directly, on this flat side. Subsequently, the conductor is welded to this side in the area arranged on this side. It is particularly preferred that, when laser welding the contact element and the conductor, the area of ​​the conductor that is also pressed and / or ultrasonically welded is welded; in other words, when performing laser welding, the laser is applied directly to the ultrasonically welded and / or pressed area of ​​the conductor. Because the distance between the conductors relative to each other is relatively small in the pressed / ultrasonically welded area, this method enables a particularly reliable connection between the conductor and the contact element.

[0020] Here, the contact element forms a (single cell) terminal. That is, the contact element is electrically connected to the conductor of the first electrode, wherein, in the installed state of the single cell, the contact element can be electrically and / or mechanically contacted from outside the single cell, particularly for connecting the contact element to the conductor track of the battery circuit. The contact element is suitably constructed as an integral (monolithic) part, particularly as a metal part. The contact element passes through the single cell cover. Here, the flat side of the soldered conductor forms the inner side of the single cell of the contact element. That is, the soldering of the conductor is performed on the inner side of the single cell of the contact element. For example, the contact element includes a plate-shaped section that forms the flat side, wherein a suitable pin-shaped protrusion extends from the plate-shaped section and passes through the single cell cover.

[0021] In particular, the contact elements are formed integrally, that is, as a whole. Furthermore, the single-pool cover is suitably constructed as an assembly structure (Zusammenbau), meaning it is pre-installed. In other words, it is not necessary to join the cover components together after welding.

[0022] Subsequently, a single-cell cover is placed on the electrode stack such that the flat side of the single-cell cover, particularly the contact element of the welding conductor, is parallel to the first end side. For this purpose, the conductor of the first electrode, particularly in its unpressed region, is bent (curled) such that the single-cell cover, after bending, covers the end side of the electrode stack in the longitudinal direction. In summary, the single-cell cover is folded up. That is, it is particularly preferable to place the single-cell cover at the first end side of the electrode stack.

[0023] Bending (curling) is suitably performed using two cutters (Schwerts) that extend laterally and are spaced apart from each other in the longitudinal direction, wherein one cutter presses down from above with respect to the stack height relative to the conductor, and the other cutter presses down from below. In summary, the flat side forming the inner side of the contact element, i.e., the side of the contact element for welding the contact metal sheet, is adjusted towards the first end side due to bending.

[0024] Preferably, after aligning the single cell cover parallel to the first end side, the single cell cover is pushed onto the electrode stack, particularly in the opposite direction to the longitudinal direction.

[0025] In summary, a method for manufacturing a single battery cell has been advantageously realized, wherein the conductors of the single battery cell are arranged at the opposite ends of an electrode stack.

[0026] The single-cell cover includes, for example, a barrier frame, particularly electrically insulating, and an outer wall, wherein, in the installed state, the outer wall is arranged on the outside of the single cell, and the barrier frame is arranged on the side of the outer wall facing the internal space of the single cell. Contact elements suitably forming terminals pass through both the barrier frame and the outer wall.

[0027] The preferred single-cell cover has a blocking frame with a protrusion that extends perpendicularly to the side of the contact element, particularly protruding from the contact element. Preferably, this protrusion is pressed into the electrode stack when the single-cell cover is pushed onto the electrode stack. For example, such a protrusion is provided at the blocking frame in the lateral direction. Thus, the protrusion is pressed into the electrode stack on both sides of the conductor, that is, it enters the electrode stack. Here, the maximum penetration depth of the protrusion into the electrode stack is preferably 1 mm or less. That is, the electrode stack is at least slightly deformed. In this way, the single-cell cover is held on the electrode stack.

[0028] Suitably, the height of the protrusion, i.e., its extension in the direction perpendicular to the side of the contact element, is greater than the maximum penetration depth. For example, the height of the protrusion is between 2.5 mm and 5 mm. In this way, in the installed state, a space region is also formed between the electrode stack and the single pool cover (in addition to the protrusion), in which a particularly curved conductor can be accommodated. That is, the protrusion additionally forms a spacer retention device.

[0029] According to an advantageous design, in order to form an electrode stack, (before providing the electrode stack, and therefore before soldering the conductor of its first electrode) two relatively separate single stacks (single electrode stacks) are stacked overlapping each other. Here, each single stack includes a first electrode and a second electrode stacked vertically overlapping each other, and a diaphragm suitably disposed therebetween. Here, the first electrode and the second electrode are fixed relative to each other, for example, by means of adhesive tape (fixing tape). For example, each single stack includes between 50 and 200, particularly 100, first electrodes and between 50 and 200, particularly 100, second electrodes.

[0030] In other words, to form an electrode stack, two single stacks are stacked overlapping each other, such that the conductors of the first electrode and the conductors of the second electrode are arranged vertically overlapping each other in the stacking direction. Subsequently, the conductors of the first electrode are pressed together and welded together.

[0031] Advantageously, when forming an electrode stack from a single stack, the deviation in the positioning of the electrodes relative to each other is smaller compared to when forming a (unique) electrode stack using a correspondingly larger number of electrodes.

[0032] As an alternative to forming an electrode stack by stacking two single stacks overlapping each other, it is manufactured using a method known as butterfly welding. Here, single stacks are first arranged side-by-side such that their ends face each other with respect to the conductors of the first electrode, wherein the single stacks can be tilted vertically. Specifically, the conductors of the two single stacks are arranged close to each other, such that the uppermost conductor of the first single stack, facing the conductor of the second single stack, is placed on top of the uppermost conductor of the second single stack, facing the conductor of the first single stack. The conductors of the first electrode are then welded together, preferably by ultrasonic welding. Subsequently, one of the single stacks is folded onto the other single stack to form the electrode stack.

[0033] According to an advantageous design, a protective foil, particularly an electrically insulating protective foil, is provided for the conductors positioned above and / or below the stack height direction. This is suitably done after the conductors are soldered to each other, and preferably after the conductors are soldered to the contact elements, and suitably before the single-cell cap is arranged on the electrode stack, such that, in particular, before the conductors are bent, the end faces are parallel to the first end side. In this way, damage to the conductors during battery cell installation, particularly during conductor bending, is advantageously avoided, or at least the risk is reduced. Furthermore, contact between the bent conductors and the edges of the second electrodes at the first end side is avoided.

[0034] Here, it is preferable that the corresponding protective foil protrudes from the conductor in the transverse direction, which is oriented laterally to the longitudinal direction and the stacking direction. In other words, the protective foil protrudes from the conductor on the side, that is, along the short edge of the first segment of the substrate. Preferably, for relatively reliable retention, the protective foil is also fixed, particularly adhered, to the upper or lower side of the electrode stack in a segmented manner, especially relative to the longitudinal direction at the end side.

[0035] Here, "upper side" should be understood as the side of the electrode stack that is above the stacking direction, and "lower side" should be understood as the side of the electrode stack that is below the stacking direction. The upper and lower sides are oriented perpendicular to the stacking direction.

[0036] In particular, welding strips are used as protective foil.

[0037] According to a preferred embodiment of the method, suitably before arranging the single pool cover at the first end side by bending the conductor, i.e., before arranging the side side parallel to the end side on the electrode stack, an additional protective foil is used to cover the weld seam formed by welding the contact metal sheet and the contact element. For this purpose, for example, the additional protective foil is adhered to the contact metal sheet. Here, the additional protective foil at least covers the weld seam, and for example, additionally covers the area of ​​the conductor and / or contact element in the weld seam area. Due to this additional protective foil, damage to the conductor from welding residue, sharp edges of the weld seam, or burrs is avoided during the arrangement of the single pool cover.

[0038] The single-cell cap and electrode stack are suitably secured relative to each other using a fixing foil. For example, the fixing foil is wound around the electrode stack and the single-cell cap, particularly around the sides of its blocking frame oriented parallel to the longitudinal direction, and is, for example, bonded to the electrode stack and / or the single-cell cap. Subsequently, the fixing foil is suitably joined to the single-cell cap, particularly its blocking frame, for example by hot stamping or welding. In a suitable manner, the fixing foil is electrically insulating.

[0039] According to an advantageous design of the method, in the longitudinal direction, i.e. from the second end side of the electrode stack toward the first end side, the housing cover (housing frame, single-cell cover) is pushed over the blocking frame of the electrode stack and / or the single-cell cover, which is fixed to the single-cell cover, particularly by means of a fixing foil.

[0040] The outer casing is formed, for example, from a metal sheet, particularly aluminum. In summary, the outer casing forms the sidewalls of the battery cell housing, oriented parallel to the longitudinal direction. Together with the cell cover, the outer casing forms what is called a cell cover (Zellbecher). That is, the outer casing is constructed as a hollow cylinder, wherein the cylinder has a rectangular base.

[0041] According to a suitable design, the single pool cover, particularly its outer wall, is arranged on the free end side of the housing cover, especially close to this free end side. Here, a blocking frame is suitably arranged in the space enclosed by the housing cover. That is, the outer wall, in the direction perpendicular to the longitudinal direction, i.e., perpendicular to the extension direction of the housing cover, is larger than the blocking frame and larger than the opening of the housing cover. In other words, the single pool cover covers the housing cover in the longitudinal direction, and particularly in the installed state, the single pool cover is flush with the housing cover in the longitudinal direction. Here, the free end side of the housing cover is oriented perpendicular to the longitudinal direction, i.e., perpendicular to the extension direction of the housing cover.

[0042] In summary, the single pool cover closes the opening of the outer shell.

[0043] Another aspect of the invention relates to a prismatic battery cell manufactured according to a method in one of the variations shown above. That is, the battery cell comprises an electrode stack having first and second electrodes suitably stacked alternately on top of each other. Here, a conductor of the first electrode is arranged on the (first) end side of the electrode stack. The conductors are pressed together and welded together, particularly by ultrasonic welding. Furthermore, the conductors, particularly in the area of ​​ultrasonic welding, are welded to the flat side of a contact element, particularly by laser welding, wherein the contact element forms one of the cell terminals of the prismatic battery cell. Here, in the installed state of the battery cell, the cell cover, particularly the flat side of its contact element, is parallel to the first end side.

[0044] Here, the preferred electrode stack is formed by two single stacks that overlap each other.

[0045] Preferably, a protective foil, particularly an electrically insulating protective foil, is provided on the conductor located above and / or below the stack height direction relative to the stack height direction.

[0046] The preferred electrode stack and single pool cover are fixed relative to each other by means of a fixing foil.

[0047] It is preferable to use additional protective foil to cover, in particular to shield, the weld seam generated by welding the contact metal sheet and the contact element.

[0048] Preferably, the outer casing of the single-cell housing is pushed over the electrode stack (and, if present, over the blocking frame of the single-cell cover). That is, in the assembled state, the electrode stack and / or the blocking frame of the single-cell cover are arranged in the internal space of the housing, and thus in the spatial region enclosed by the outer casing. Particularly preferred is the single-cell cover, especially its outer wall, arranged on the free end side of the outer casing, that is, the single-cell cover covers the outer casing in a direction parallel to the central axis of the outer casing.

[0049] The preferred single-cell cover's blocking frame is pushed onto the electrode stack. In particular, the protrusions of the blocking frame enter the electrode stack.

[0050] Another aspect of the invention relates to an electrically driven motor vehicle having a prismatic battery cell constructed in one of the variations shown above and / or manufactured according to the method in one of the variations shown above.

[0051] In particular, the vehicle includes a traction battery (HV battery), which is configured to provide electrical power to the traction drive. Here, the prismatic battery cell is part of the traction battery. Attached Figure Description

[0052] The embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. In the drawings:

[0053] Figure 1 A flowchart illustrating the method flow for manufacturing a single battery cell is shown.

[0054] Figure 2 The diagram schematically illustrates two monolithic stacks stacked one on top of the other to form an electrode stack.

[0055] Figure 3 An electrode stack is schematically shown in perspective, wherein a first conductor is disposed at a first end of the electrode stack, and a second conductor is disposed at a second end of the electrode stack, wherein the first conductors are ultrasonically welded together at their free end sides.

[0056] Figure 4 The electrode stack is schematically shown in perspective, where the first conductor is laser-welded to the contact element of the single-cell cap.

[0057] Figure 5The electrode stack is schematically shown in perspective, wherein a protective foil covers the conductor, and another protective foil covers the laser weld seam.

[0058] Figure 6 The electrode stack and single cell cover are schematically shown in perspective, wherein the single cell cover is arranged parallel to the first end side.

[0059] Figure 7 The electrode stack is schematically shown in partial top view, with a single-cell cap pushed onto the electrode stack.

[0060] Figure 8 The electrode stack is schematically shown in perspective, wherein a second conductor is engaged with a contact metal sheet that protrudes through a blocking frame disposed at a second end, and wherein the electrode stack, the blocking frame, and the single-cell bottom plate are fixed relative to each other by means of a fixing foil.

[0061] Figure 9 The electrode stack, secured by a fixing foil, a barrier frame, and a single-cell cover, is schematically shown in perspective, wherein the housing cover is pushed through the barrier frame and the electrode stack.

[0062] Figure 10 The single pool bottom plate, joined with the contact metal sheet, is schematically shown in perspective.

[0063] Figure 11 A single battery cell is schematically shown in perspective, where a cell cover and a cell base plate enclose the outer casing.

[0064] Figure 12 A cross-sectional view through a single pool cover is shown.

[0065] In all the accompanying drawings, corresponding parts and parameters are always given the same reference numerals. Detailed Implementation

[0066] exist Figure 1 The flowchart illustrates a method for manufacturing a prismatic battery cell 2, specifically constructed as a lithium-ion battery cell.

[0067] In the method, in the first step I, two separate single stacks 4 (single electrode stacks 4) are stacked one on top of the other. This is in Figure 2 The arrows represent the numbers.

[0068] Each single stack 4 includes a plurality of first electrodes 6 and second electrodes 8, which are stacked alternately on top of each other in the stacking direction S, wherein a diaphragm (not shown) is arranged between the first electrodes and the second electrodes respectively.

[0069] The first and second electrodes 6 and 8 of each single stack 4 are constructed as sheets. Each includes a foil-like substrate having a rectangular section coated with an active material and a conductor. Hereinafter, for better distinction, the conductor of the first electrode 6 will be referred to as the first conductor 10, and the conductor of the second electrode 8 will be referred to as the second conductor 12. The first and second conductors 10 and 12 extend from the short side of the rectangular coated section. In each single stack 4, the first conductors 10 are arranged vertically overlapping each other, and the second conductors 12 are arranged vertically overlapping each other, wherein the first conductor 10 extends beyond the first section in the longitudinal direction L, and the second conductor 12 extends beyond the first section of the corresponding substrate in the opposite direction to the longitudinal direction L.

[0070] In each single stack 4, a fixing band 14 is used to fix the electrodes 6, 8 of the corresponding single stack 4. Here, the fixing band 14 is attached to the upper (top) side of the corresponding single stack 4 relative to the stacking direction S and the lower (bottom) side of the corresponding single stack 4 relative to the stacking direction S, and here it spans the side of the corresponding single stack 4 that is oriented parallel to the stacking direction S.

[0071] In the first step I, two single stacks 4 are arranged to overlap each other, such that the conductors 10 of the first electrodes 6 of the two single stacks 4 are arranged vertically overlapping in the stacking direction S. Correspondingly, the conductors 12 of the second electrodes 8 of the two single stacks 4 are arranged vertically overlapping in the stacking direction S.

[0072] By means of the overlapping stacking of two single stacks 4, a first conductor 10 is disposed on one side of the formed electrode stack 16, which is referred to as the first end side 18. A second conductor 12 is disposed on the second end side 20 of the electrode stack 16, which is opposite to the first end side 18, that is, it is oriented parallel to the first end side 18 and oriented perpendicular to the stacking direction S. That is, the longitudinal direction L points from the second end side 20 to the first end side 18.

[0073] Two single stacks 4 that are stacked vertically are secured relative to each other by means of a fixing strap 14.

[0074] In summary, an electrode stack 16 is generated by the overlapping stacking of two single stacks 4, which is provided for further fabrication of a battery cell 2, wherein the conductor 10 of the first electrode 6 extends from the first end side 18 of the electrode assembly 16 in the longitudinal direction L, and the conductor 12 of the second electrode 8 extends from the second end side 20 opposite to the longitudinal direction L.

[0075] In the subsequent second step II, the conductors 10 of the first electrode 6 are pressed together and welded together. For this purpose, the first conductors 10 are ultrasonically welded together using an ultrasonic welding tool 22. Figure 3 The diagram shows, where the ultrasonic tool 22 is schematically represented as a rectangle. During ultrasonic welding, the first conductors 10 are not only pressed together, but also joined to each other. Suitably, the first conductors 10 are subsequently trimmed, in other words, shortened or trimmed, so that their free ends, i.e., their ends facing away from the first end side 18, are flush with each other.

[0076] In the subsequent third step III, the pressed first conductor 10 is arranged on the flat side 24 of the contact element 26 of the single-pool cover 28 of the single-pool housing 30. Specifically, the pressed area of ​​the first conductor 10 is placed directly, i.e., perpendicularly, on the flat side 24. Subsequently, the pressed first conductors 10 are welded to this side 24, particularly by means of laser welding, see [reference needed]. Figure 4 Therefore, a laser is used to act on the ultrasonic welding area of ​​the first conductor 10, thereby welding the first conductor 10 and the contact element 26 together by laser.

[0077] Especially Figures 4 to 6 China and in Figure 12 The cross-sectional view provides a relatively better view of the structure of the single-cell cover 28. The single-cell cover 28 includes a suitably flat (single-cell) outer wall 32. On its (inner) side facing the electrode stack 16, i.e., on the side facing the internal space of the single-cell battery 2, a particularly electrically insulating barrier frame 34 is arranged. Preferably, the barrier frame 30 of the single-cell cover 28 has at least one protrusion 36 extending perpendicularly to the side 24 of the contact element 26 toward the interior of the single cell; that is, the protrusion 36 extends in the opposite direction to the longitudinal direction L in the assembled state of the single-cell battery 2. According to the embodiment shown here, the barrier frame 34 has two such protrusions 36, which are arranged at their ends in a manner spaced apart from each other in the transverse direction Q.

[0078] Contact element 26 passes through both the barrier frame 34 and the outer wall 32, thus making contact element 26 electrically connected not only to the first conductor 10 inside the single cell but also electrically and mechanically contactable outside the single cell. Therefore, contact element 26 forms the terminal of the battery single cell 2. Contact element 26 is specifically constructed as a single piece (integral) as a metal component. Contact element 26 includes a plate-shaped section 38, the side of which facing the electrode stack 16 forms a flat side 24. A pin-shaped protrusion 40 is formed on this plate-shaped section 38, extending from the plate-shaped section 38 and passing through the single cell cover 28.

[0079] Furthermore, the single pool cover 28 is constructed as an assembly structure, meaning that the single pool cover 28 is pre-installed.

[0080] In the subsequent fourth step IV, an electrically insulating protective foil 42 is provided for the first conductor 10 that is located above and / or below the stack height direction S.

[0081] Optionally, the protective foil 42 protrudes from the first conductor 10 in the transverse direction Q, which is oriented transversely to the longitudinal direction L and the stacking direction S. That is, the corresponding protective foil 42 extends laterally from the conductor 10. For relatively reliable retention, the protective foil 42 is also fixed, particularly adhered, to the upper side 44 of the electrode stack or the lower side 46 of the electrode stack 16 in a segmented manner, especially relative to the longitudinal direction at the end sides. In other words, the protective foil 42 extends correspondingly on the upper side 44 or lower side 46 of the electrode stack 16 through the region of the edge of the electrode stack 16 where the corresponding conductor 10 is arranged.

[0082] Here, the upper side 44 should be understood as the side of the electrode stack 16 located above the stacking direction S, and the lower side 46 should be understood as the side of the electrode stack 16 located below the stacking direction S. The upper side 44 and the lower side 46 are oriented perpendicular to the stacking direction S.

[0083] In particular, welding strips are used as protective foil 42.

[0084] For example in Figure 5 The protective foil 42 that has been installed can be seen in the image.

[0085] Furthermore, in this fourth step IV, an additional protective foil 50 is used to cover the (laser) weld 48 formed by laser welding the first conductor 10 and the contact element 26, see also Figure 5 Here, the additional protective foil 50 completely covers the weld 48. In this way, the first conductor 10 itself is prevented from being damaged, particularly by welding residue or by the weld 48. Suitably, for relatively reliable retention, the areas of the side 24 not covered by the first conductor 10 are additionally covered by the additional protective foil 50, and the additional protective foil 50 is adhered to these areas.

[0086] In the subsequent fifth step V, a single pool cover 28 is arranged on the electrode stack 16 such that the single pool cover 50, particularly the side 24 and / or the outer wall 32, is parallel to the first end side 18. For this purpose, the first conductor 10 is bent in the area where it is not soldered to the contact element 26. In other words, the free end of the first conductor 10 is adjusted to face the first end side 18.

[0087] Subsequently, in this fifth step V, the single-cell cover 28 is pushed onto the electrode stack 16. Here, the protrusion 36 is pressed into the electrode stack 16, which... Figure 6 The arrows are used to indicate this. In the installed state, the protrusions 36 are pressed into the electrode stack 16 on both sides of the first conductor 10 relative to the lateral direction Q; that is, they enter the electrode stack 16. Specifically... Figure 6 and Figure 7 The image shows a single pool cover 28 arranged on the first end side 18. Here, as particularly... Figure 7 As can be seen, the corresponding protrusion 36 enters the electrode stack 16 at a maximum depth w of 1 mm or less. That is, the electrode stack 16 is at least slightly deformed so that the single pool cover 28 is held on the electrode stack 16.

[0088] In the subsequent sixth step VI, the second conductors 12 are pressed together and preferably welded together, and suitably then trimmed. For example, for this purpose, the second conductors 12 are ultrasonically welded together at least partially, for example point-by-point or segment-by-segment, such that their relative to each other is predetermined. Subsequently, the pressed second conductors 12 are introduced between the contact metal sheet 52 and the sacrificial metal sheet 54 and ultrasonically welded thereto. Optionally, a protective foil 42, particularly electrically insulating, is provided for the second conductors 10 located above and / or below the stack height direction S.

[0089] In the subsequent seventh step VII, an additional blocking frame 56 (second blocking frame 56) is arranged at the second end 20. Here, the contact metal piece 52, which is welded to the second conductor 12, is guided through the sleeve 58 of the second blocking frame 56, which passes through in the longitudinal direction L. In other words, the blocking frame 56 is pushed past the contact metal piece 52 and the second conductor 12, such that the contact metal piece 52 and the second conductor 12 pass through the sleeve 58 of the second blocking frame 56. This is in Figure 8 As shown in the image.

[0090] For example, in a similar manner to the (first) blocking frame 34, the second blocking frame 56 is pushed onto the second end side 18 so that its protrusion enters into the electrode stack 16 (not shown further).

[0091] In the subsequent eighth step VIII, the electrode stack 16, the single-cell cover 28, and the second blocking frame 56 are fixed relative to each other using, in particular, an electrically insulating fixing foil 60. For this purpose, the fixing foil 60 is wound around the electrode stack 16, and around the side 72 of the blocking frame 34 of the single-cell cover 28, which is oriented parallel to the longitudinal direction L, and around the side 72 of the second blocking frame 34, which is also oriented parallel to the longitudinal direction L. Figure 8The arrows indicate this. For example, after the winding process, the fixing foil 60 is secured with tape 52. Furthermore, the fixing foil 60 is welded to the blocking frame 34 and the second blocking frame 56 at their sides 72, which are oriented parallel to the longitudinal direction L, or joined together by hot stamping.

[0092] In the subsequent ninth step IX, the outer casing 62 of the single-cell housing 30 is pushed past the contact metal sheet 52, the second blocking frame 56, and the electrode stack 16, see also Figure 9 Here, the outer shell 62 encloses the internal space of a single pool, that is, it forms the sidewalls of the single pool shell 30 that are oriented parallel to the longitudinal direction L. In other words, the outer shell 62 is constructed as a hollow prism (a hollow cylinder with a rectangular base).

[0093] The electrode stack 4 and the blocking frame 34 are arranged in the housing cover 62, that is, housed within the space area enclosed by the housing cover 62.

[0094] In the subsequent tenth step X, the contact element 26 between the contact metal sheet 52 and the single-pool bottom plate 66 of the single-pool housing 30 is laser welded, see also [link to previous step X]. Figure 10 Here, contact element 26 forms another terminal of battery cell 2, meaning that contact element 26 can be electrically and / or mechanically contacted from outside battery cell 2, see [link to relevant documentation]. Figure 11 In other words, the contact metal sheet 52 is welded inside the single pool of the contact element 26. In summary, the contact element 26 is electrically connected to the second conductor 12 via the contact metal sheet 52. Optionally, an additional protective foil 50 is used to cover the (laser) weld 48 formed by welding the contact metal sheet 52 to the contact element 26.

[0095] In the subsequent eleventh step XI, the single pool cover 28 is arranged on the free end side 64 of the outer casing 62, see also Figure 12 Therefore, the single pool cover 28 is placed on the free end side 64. Here, the free end side 64 should be understood as the side of the housing cover 62 that is oriented perpendicular to the longitudinal direction L and therefore perpendicular to the extension direction or central axis of the housing cover 62.

[0096] In addition, the single pool bottom plate 66 is arranged on the other free end side 64 of the outer shell 62, see also Figure 11 For this purpose, the second conductor 12 is correspondingly bent, particularly folded, and / or rolled, especially in its uncompressed areas. Thus, a single-cell base plate 66 is placed on this free end side 64. That is, the single-cell base plate 66 is arranged such that it covers the second blocking frame 56 and the second end side 20 of the electrode stack 16.

[0097] The single pool cover 28 and the single pool bottom plate 66 respectively close the opening 68 of the outer shell 62. Suitablely, the single pool bottom plate 66 and the single pool cover 28 are welded together with the outer shell 62, particularly by laser welding in a fluid-tight manner, to form a cuboid single pool shell.

[0098] Subsequently, electrolyte is filled into the battery cell 2 through the filling opening 70 arranged in the cell base plate 66 in a suitable manner. For example, the filling opening 70 is then closed using a pin, particularly a pin made of an elastomer. Subsequently, the filling opening 70 and the pin housed therein are covered, for example, by a cover made particularly of metal, and welded to the outside of the cell base plate 66. Thus, the filling opening 70 is closed in a sealed manner.

[0099] In a manner not shown in detail, electrically driven motor vehicles, particularly their traction batteries, have prismatic battery cells 2 manufactured according to the method shown above.

[0100] This invention is not limited to the embodiments described above. Rather, within the scope of the claims, those skilled in the art can derive other variations of the invention without departing from its subject matter. In particular, all individual features in conjunction with the embodiments and / or described in the claims can also be combined with each other in other ways without departing from the subject matter of the invention.

[0101] List of reference numerals

[0102] 2-cell single battery

[0103] 4 single stacks

[0104] 6 First Electrode

[0105] 8 Second electrode

[0106] 10 Conductor of the first electrode

[0107] 12 Conductor of the second electrode

[0108] 14 fixing straps

[0109] 16-electrode stack

[0110] 18 First end side

[0111] 20 Second end side

[0112] 22 Ultrasonic Tools

[0113] 24. Side of contact element

[0114] 26 contact elements / terminals

[0115] 28 Single Pool Cover

[0116] 30 Single Pool Shell

[0117] 32 outer wall

[0118] 34 (First) Barrier Frame

[0119] 36 protrusions

[0120] 38 plate-like sections

[0121] 40 pin-shaped protrusions

[0122] 42 protective foil

[0123] The top side of the 44-electrode stack

[0124] The lower side of the 46-electrode stack

[0125] 48 welds

[0126] 50 additional protective foils

[0127] 52 contact metal sheet

[0128] 54 sacrificial metal pieces

[0129] 56 (Second) Blocking Frame

[0130] 58 casings

[0131] 60 fixed foil

[0132] 62 Housing Cover

[0133] 64 Free end side

[0134] 66 Single Pool Bottom Plate

[0135] 68 opening

[0136] 70 Filling Opening

[0137] 72 side view

[0138] L longitudinal direction

[0139] Q horizontal direction

[0140] S Stack height direction / Stack direction

[0141] w entry depth

[0142] I form an electrode stack

[0143] II. The first conductors are ultrasonically welded together.

[0144] III. Conductors that are welded together are laser-welded onto contact elements.

[0145] IV. Install protective foil

[0146] V pushes the single-cell cover onto the electrode stack.

[0147] VI. Bond the second conductor to the contact metal sheet.

[0148] VII pushes the second blocking frame

[0149] VIII secures the single-cell cover to the electrode stack.

[0150] IX push housing cover

[0151] X welds the contact metal sheet to the contact element of the single pool bottom plate.

[0152] XI Enclosed Housing Cover

Claims

1. A method for manufacturing a prismatic battery single cell (2), - wherein, An electrode stack (16) is provided, the electrode stack having a first electrode (6) and a second electrode (8) stacked vertically, wherein the conductor (10) of the first electrode (6) extends from the end side (18) of the electrode assembly (16) in the longitudinal direction (L). - In this process, the conductors (10) of the first electrode (6) are pressed together and welded together, particularly by ultrasonic welding. - In this arrangement, a compressed conductor (10) is placed on the flat side (24) of the contact element (26) forming the single-cell terminal of the single-cell cover (28) of the single-cell housing (30), and is welded to the contact element (26), particularly by laser welding. - wherein the single pool cover (28) is arranged on the electrode stack (16), particularly pushed onto the electrode stack, such that the single pool cover (50), particularly the side (24), is parallel to the end side (18).

2. The method according to claim 1, Its features are, In order to form the electrode stack (16), two single stacks (4) that are separated from each other are stacked on top of each other, the single stacks having a first electrode (6) and a second electrode (8) that are stacked on top of each other and fixed relative to each other.

3. The method according to claim 1 or 2, Its features are, A protective foil (42) is provided, in particular, for conductors (10) that are located above and / or below the stack height direction (S).

4. The method according to any one of claims 1 to 3, Its features are, The weld (48) formed by welding the conductor (10) and the contact element (26) is covered with an additional protective foil (50).

5. The method according to any one of claims 1 to 4, Its features are, The electrode stack (16) and the single pool cover (28) are fixed relative to each other by means of a fixing foil (60).

6. The method according to any one of claims 1 to 5, Its features are, The single pool cover (28) has a barrier frame (SR) having a protrusion (36) extending perpendicularly to the side (24), and / or wherein, When the single pool cover (28) is pushed onto the electrode stack (16), the protrusion (36) is pressed into the electrode stack (16).

7. The method according to any one of claims 1 to 6, Its features are, The outer casing (62) of the single-cell housing (30) is pushed in the longitudinal direction (L) over the electrode stack (16) which is fixed to the single-cell cover (28) in particular by means of the fixing foil (60).

8. The method according to claim 7, Its features are, The single pool cover (28) is arranged on the free end side (64) of the outer casing (62).

9. A prismatic battery cell (2), said battery cell being manufactured according to any one of claims 1 to 8.

10. Motor vehicle having a battery cell (2) according to claim 9.

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