Battery cell housing and method for producing a battery cell housing

Abstract

The invention relates to a method for producing a battery cell housing (1) which is designed to receive an electrode assembly (3), comprising the method steps of: • separating a metal sheet (2); • shaping a plurality of metal sheet portions of the metal sheet (2), which are integrally connected to one another, in order to partially form an enclosure for the electrode assembly (3); • positioning, contacting and inserting the electrode assembly (3) into the partially formed enclosure for receiving the electrode assembly (3); • shaping and integrally bonding at least two metal sheet portions arranged on one another to close the battery cell housing (1). The invention further relates to a battery cell housing (1) for receiving and completely enclosing an electrode assembly (3), wherein the battery cell housing (1) is formed by shaping metal sheet portions of a single metal sheet (2), wherein at least two metal sheet portions arranged on one another are integrally bonded to one another to close the battery housing (1).

Description

[0001] P250180 DE

[0002] - 1 - Battery cell housing and method for manufacturing a battery cell housing

[0003] The invention relates to a method for manufacturing a battery cell housing configured to receive an electrode arrangement. The invention further relates to a battery cell housing for receiving an electrode arrangement and a battery cell with an electrode arrangement arranged in such a battery cell housing. In particular, the battery cell is designed as a prismatic cell.

[0004] For example, EP 2958 180 B1 discloses a battery cell configured to have a structure in which an electrode arrangement comprising positive electrodes, negative electrodes, and separators, each arranged between the positive and negative electrodes, is mounted in a battery housing, wherein the electrode arrangement is provided with a deformation element whose cross-sectional width is discontinuously or continuously reduced. The battery housing comprises one or more housing elements, each made of a metal sheet, wherein the housing elements are coupled to one another in a state in which the electrode arrangement is mounted in the housing elements. At least one of the housing elements is provided with a receiving element having an internal shape corresponding to the deformation element of the electrode arrangement.The battery housing comprises a first housing element, which has a receiving part in which the electrode assembly is received, the first housing element being open at one end, and a second housing element, which is coupled to the open end of the first housing element for sealing the receiving part, and the second housing element being made of a plate-shaped element having a shape corresponding to the open end of the first housing element. The second housing element has a stepped shape and is provided with a protruding terminal corresponding to the positive electrode terminal or the negative electrode terminal.

[0005] Furthermore, DE 102020 110700 A1 discloses a method for manufacturing a battery for a motor vehicle, wherein the battery has several prismatic battery cells arranged in a battery housing of the battery and each has two terminals for electrical contacting the battery cell and a cell housing with P250180 DE

[0006] -2 -have an outlet opening. First, a sheet metal part is prepared and subjected to a stamping process, resulting in a sheet metal part. Subsequently, beads are introduced into this sheet metal part to facilitate the simple forming of four walls relative to a base wall. Then, four walls are bent relative to the base wall to finally form the sheet metal part. The sheet metal part, which forms the cell housing, remains open on one side.

[0007] The object of the invention is to provide an alternative battery cell housing and a method for manufacturing the battery cell housing. In particular, the manufacturing costs and effort for the battery cell housing are to be reduced. This object is achieved by the subject matter of claim 1 and the subject matter of claim 9. Preferred embodiments can be found in the dependent claims, the description, and the figures.

[0008] An inventive method for manufacturing a battery cell housing designed to receive an electrode arrangement comprises the following process steps: separating a metal sheet, forming several integrally connected metal sheet sections of the metal sheet to partially form an enclosure for the electrode arrangement, positioning, contacting and inserting the electrode arrangement into the partially formed enclosure to receive the electrode arrangement, and forming and metallurgically joining at least two adjacent metal sheet sections to close the battery cell housing.

[0009] The method according to the invention enables the production of the battery cell housing, which is designed to receive and completely enclose the electrode assembly. The battery cell housing is formed by forming sections of a single metal sheet. To close the battery housing, at least two adjacent metal sheet sections are joined together by a material bond. The battery cell housing and the electrode assembly form a battery cell. The electrode assembly comprises at least positive electrodes, negative electrodes, and separators, each arranged between the positive and negative electrodes. P250180 DE

[0010] - 3 - For example, the intended geometry of the metal sheet can be cut from sheet metal by rolling, punching, or laser cutting. In particular, the metal sheet has a substantially constant wall thickness, so that all side surfaces of the battery cell housing have substantially the same thickness. Advantageously, no additional components, such as lids, are necessary to close the battery cell housing. The battery cell housing is closed by forming and joining at least two sections of the metal sheet.

[0011] By forming the metal sheet, the housing for the electrode assembly is partially formed, in particular to such an extent that contacting and insertion of the electrode assembly into the housing is possible. For example, at least one connection for electrically contacting the electrode assembly is arranged on the metal sheet. According to one embodiment, at least two connections for electrically contacting the electrode assembly are arranged on the metal sheet. For example, a positive and a negative electrical connection are arranged on the metal sheet after it has been cut. The positioning, contacting, and insertion of the electrode assembly take place in a single process step, whereby the sequence of the individual steps can be changed.For example, the electrode assembly is positioned within the partially formed housing using a gripper. Electrical contact is then made while the electrode assembly is held by the gripper, and finally, it is placed into the housing. Alternatively, the electrode assembly can first be placed into the housing, then positioned within it, and subsequently electrically contacted. Thus, the insertion, positioning, and contacting of the electrode assembly are performed in a single process step. This approach saves time and costs and simplifies manufacturing. In particular, it eliminates the need to pull the electrode assembly through the housing. Furthermore, placing the electrode assembly into the partially formed housing allows for simplified visual inspection of the position and contact of the electrode assembly within the housing.Electrical contacting of the electrode arrangement means attaching the current collector flag of the electrode arrangement to the electrical connections by means of a mechanical joining process or by ultrasonic or La-P250180 DE.

[0012] - 4 -serschweißen to be understood. The closing of the housing and the finalization of the manufacture of the battery cell housing is carried out by joining, in particular welding or gluing, at least two adjacent metal sheet sections.

[0013] During the forming of the metal sheet, sections of the metal sheet are bent or folded. According to one embodiment, at least five sections of the metal sheet are formed by bending. This creates all six side surfaces of the enclosure, leaving the enclosure partially open to allow the electrode assembly to be inserted through the open side. Specifically, the electrode assembly is inserted into the partially formed enclosure via a relatively long edge, namely along the longitudinal side. This long edge provides the largest opening in the enclosure and simplifies not only the insertion process but also the subsequent visual inspection of the electrode assembly within the enclosure.

[0014] Furthermore, when forming the metal sheet, not only bends but also notches can be created. For example, the notches can extend parallel to the side edges over part or the entire length of the metal sheet. Incorporating notches simplifies the forming, especially folding, of the metal sheet sections and thus the production of the housing. Bends can also be used to support another metal sheet section and to simplify the material-bonded connection. Notches can be designed to create predetermined breaking points, particularly with a valve function for pressure release from the battery cell housing in case of malfunction.

[0015] According to one embodiment, the respective notch penetrates at least 20% and at most 75% into the surface of the metal sheet. Thus, the respective notch is to be understood as a depression in the surface of the metal sheet. For example, the respective notch has an opening angle of at least 90°. This simplifies subsequent forming, in particular bending or folding of the metal sheet sections along the respective notch. Furthermore, this also increases the precision of the manufacturing process for the battery cell housing. P250180 DE

[0016] - 5 - According to one embodiment, the metal sheet is made of a steel alloy or an aluminum alloy. For example, the metal sheet is made of stainless steel. This allows the sheet thickness of the battery cell housing to be further reduced.

[0017] According to one embodiment, the metal sheet is at least partially or completely coated with a polymer. For example, the surface of the metal sheet, which serves as the outer surface of the battery cell housing, is coated with a polymer either before forming or after the metal sheet sections have been joined, thereby simplifying a subsequent painting process of the battery cell housing.

[0018] According to one embodiment, at least one section of the metal sheet, designed as the outer housing base, is structured to optimize the thermal connection to a cooling device. For example, the structuring takes place after the metal sheet has been cut. The structuring enables the housing base to conform elastically to a cooling plate of the cooling device, on which the battery cell is mounted. A thermal conductor can be arranged between the housing base and the cooling plate to improve the thermal connection and thus also the cooling of the electrode assembly located in the battery cell housing.

[0019] Further measures improving the invention are described in more detail below, together with a description of preferred embodiments of the invention, with reference to the figures.

[0020] Figure 1 shows a highly simplified schematic representation of a metal sheet according to a first embodiment of the invention.

[0021] Figure 2 shows a highly simplified schematic representation of a battery cell according to the invention.

[0022] Figure 3 is a highly simplified schematic representation of a section of the battery cell according to Figure 2, P250180 DE

[0023] - 6 -

[0024] Figure 4 shows a highly simplified schematic representation of a metal sheet according to a second embodiment of the invention.

[0025] Figure 5 shows a highly simplified schematic representation of a metal sheet according to a third embodiment of the invention and

[0026] Figure 6 shows a block diagram of the inventive method for manufacturing the battery cell housing.

[0027] Figure 1 shows a metal sheet 2 configured to form a battery cell housing 1 according to Figure 2. The metal sheet 2 has seven interconnected metal sheet sections, with three metal sheet sections arranged horizontally in a row and five metal sheet sections arranged vertically in a row. A notch 5 is formed between each pair of metal sheet sections, designed to simplify folding, in particular bending, the respective metal sheet section. Furthermore, two terminals 7 for electrically contacting an electrode arrangement 3, which is shown in Figure 2, are arranged on the metal sheet 2. The position of the terminals 7 is only exemplary and can be changed.

[0028] Figure 2 shows a highly simplified representation of the battery cell 8, comprising the battery cell housing 1 and the electrode assembly 3. The battery cell housing 1 contains the electrode assembly 3 and completely encloses it, i.e., on all six sides. The battery cell housing 1 is formed by forming a single metal sheet 2. At least two adjacent metal sheet sections of the metal sheet 2 are joined together to close the battery cell housing 1 by a material bond, for example, by welding or bonding. The battery cell housing 1 can be made of a steel alloy or an aluminum alloy and may have a polymer coating on at least part of its outer surface. In this case, a metal sheet section of the metal sheet 2, configured as the outer housing base 6, is structured to improve the thermal connection to a cooling device (not shown in detail).The structuring allows the base of the battery cell housing 1 to fit snugly against the P250180 DE.

[0029] -7 - Cooling device and consists of a pattern of indentations which is introduced into the surface of the metal sheet section by rolling.

[0030] Figure 3 shows a section of the battery cell 8 according to Figure 2. The battery cell housing 1 is closed and contains the electrode assembly 3. A bend 4 on a metal sheet section of the metal sheet 2 is designed to form a support for part of another metal sheet section of the metal sheet 2, thus facilitating the creation of a material-fit connection between the two adjacent metal sheet sections for closing the battery cell housing 1. The long edge of the metal sheet 2 is closed after the electrode assembly 3 has been placed into the housing formed by the bending process.

[0031] Figure 4 shows a further embodiment of a metal sheet 2 configured to form a battery cell housing 1. The metal sheet 2 has seven interconnected metal sheet sections, with three metal sheet sections arranged horizontally in a row and five metal sheet sections arranged vertically in a row. The difference from the first embodiment of the metal sheet 2 is that the bend 4 shown in Figure 3 is omitted, and instead the two metal sheet sections are joined materially at the center of a side surface of the battery cell housing 1, without any overlap of the metal sheet sections to be joined. Alternatively, an overlap of the metal sheet sections to be joined can be provided.A notch 5 is formed between each pair of metal sheet sections, designed to simplify folding, in particular bending, of the respective metal sheet section. Furthermore, two terminals 7 for electrically contacting the electrode arrangement 3 are arranged on the metal sheet 2.

[0032] Figure 5 shows a further embodiment of a metal sheet 2, which is configured to form a battery cell housing 1. The metal sheet 2 has seven interconnected metal sheet sections, wherein two sets of two metal sheet sections are arranged horizontally in a row and five metal sheet sections are arranged vertically in a row. A notch is provided between each pair of metal sheet sections. 5P250180 DE

[0033] - 8 - designed to simplify the folding, in particular the bending, of the respective metal sheet section. Furthermore, two terminals 7 for electrical contacting the electrode arrangement 3 are arranged on the metal sheet 2.

[0034] Figure 6 shows a method for manufacturing the battery cell housing 1, which is configured to receive the electrode arrangement 3. According to a first method step 10, the metal sheet 2 is formed by cutting from a metal strip. For example, the metal sheet 2 can have the geometry shown in Figure 4 and be made of a steel alloy or an aluminum alloy. Optionally, the metal strip can have a polymer coating on one side, with this side being designated as the outer surface of the battery cell housing 1.

[0035] According to a second process step 20, two terminals 7 for electrical contacting the electrode arrangement 3 are arranged on the metal sheet 2. In the same process step, a metal sheet section of the metal sheet 2, designed as an outer housing base 6, can be structured to optimize the thermal connection to a cooling device, for example by rolling.

[0036] Subsequently, according to a third process step 30, the metal sheet 2 is formed, whereby notches 5 are first introduced into the surface of the metal sheet 2. The notches 5 are designed as depressions and penetrate at least 20% to a maximum of 75% into the surface of the metal sheet 2.

[0037] According to a fourth process step 40, five metal sheet sections of metal sheet 2 are bent at the notches 5 to create the walls for a partially open enclosure. The notches 5 simplify the bending of the metal sheet sections.

[0038] According to a fifth process step 50, the positioning, contacting, and insertion of the electrode arrangement 3 into the housing, which is open along one long edge, are carried out in a single process step. For example, the electrode arrangement 3 is positioned in the area of ​​the housing using a gripper, then P250180 DE

[0039] - 9 - Electrical contact is made to the electrode assembly 3 while it continues to be held by the gripper, and finally, it is placed into the housing. This procedure saves time and costs and simplifies manufacturing. Furthermore, placing the electrode assembly 3 into the partially formed housing allows for a simplified visual inspection of its position and contact within the housing. During electrical contact, the current collector tabs of the electrode assembly 3 are connected to the electrical terminals 7, for example, by ultrasonic welding.

[0040] According to a sixth procedure step 60, the electrode arrangement 3 in the housing is tested.

[0041] According to a seventh process step 70, the open part of the housing is reshaped, in particular the still open metal sheet section is bent further in such a way that two adjacent and not directly connected metal sheet sections come into contact with each other and are directly connected by material bonding, thereby closing the battery cell housing 1.

[0042] In an eighth process step 80, a leak test is carried out on the battery cell 8, consisting of the battery cell housing 1 and the electrode arrangement 3 arranged therein.P250180 DE

[0043] - 10 - List of reference symbols

[0044] 1 battery cell casing

[0045] 2 metal sheets

[0046] 3 Electrode arrangement

[0047] 4 bends

[0048] 5 notch

[0049] 6 Case base

[0050] 7 connection

[0051] 8 battery cells

[0052] 10 first procedural step

[0053] 20 second procedural step

[0054] 30 third procedural step

[0055] 40 fourth process step

[0056] 50 fifth procedural step

[0057] 60 sixth procedural step

[0058] 70 seventh process step

[0059] eighth process step

Claims

1. P250180 DE - 11 - Patent claims 1. Method for manufacturing a battery cell housing (1) designed to accommodate an electrode arrangement (3), comprising the process steps of: • Cutting a metal sheet (2), • Forming several in-seam metal sheet sections (2) to partially form an enclosure for the electrode arrangement (3), • Positioning, contacting and inserting the electrode arrangement (3) into the partially formed housing for receiving the electrode arrangement (3), • Forming and joining at least two adjacent metal sheet sections to close the battery cell housing (1).

2. Method according to claim 1, characterized in that, after the metal sheet (2) is cut, bends (4) and / or notches (5) are formed in the metal sheet (2).

3. Method according to claim 2, characterized in that the respective notch (5) penetrates at least 20% to a maximum of 75% into the surface of the metal sheet (2).

4. Method according to any one of the preceding claims, characterized in that at least five metal sheet sections of the metal sheet (2) are formed by bending.

5. Method according to any one of the preceding claims, characterized in that the metal sheet (2) is at least partially coated with a polymer.

6. Method according to any one of the preceding claims, characterized in that the metal sheet (2) is made of a steel alloy or an aluminum alloy. P250180 DE - 12 - 7. Method according to any of the preceding claims, characterized in that at least one metal sheet section of the metal sheet (2) designed as an outer housing base (6) is structured to optimize the thermal connection to a cooling device.

8. Method according to any one of the preceding claims, characterized in that at least one connection (7) for electrical contacting of the electrode arrangement (3) is arranged on the metal sheet (2).

9. Battery cell housing (1) for receiving and completely enclosing an electrode arrangement (3), wherein the battery cell housing (1) is formed by forming metal sheet sections of a single metal sheet (2), wherein at least two adjacent metal sheet sections are materially joined together to close the battery housing (1).

10. Battery cell (8) with an electrode arrangement (3) comprising at least positive electrodes, negative electrodes and separators, each arranged between the positive electrodes and the negative electrodes, wherein the electrode arrangement (3) is arranged in a battery cell housing (1) according to claim 9.

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