Multi-pole tab cell manufacturing method and tab

Abstract

The application provides a multi-tab cell manufacturing method and a tab, and the multi-tab cell manufacturing method comprises the following steps: stacking a plurality of foil tabs on each other to form a foil tab group; cutting off both ends of the foil tab group along the width direction of the foil tab group, so that the width of a to-be-welded area of the foil tab group is the same as a preset width; and welding a metal strip tab and the remaining part of the foil tab group. The method can reduce the risk of misalignment of the to-be-welded areas of different foil tabs, thereby improving the welding quality of the foil tabs and the metal strip tab.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method for manufacturing a multi-tab battery cell and an electrode sheet. Background Technology

[0002] Multi-tab cells are a common type of battery cell with relatively low internal resistance. One type of multi-tab cell has an electrode structure consisting of foil electrodes and metal strip electrodes. Taking a wound multi-tab cell as an example, the electrode sheet includes a main body and multiple foil electrodes. The foil electrodes are connected to the same end of the main body and spaced apart along the length of the electrode sheet. After the electrode sheet is wound, the multiple foil electrodes on the electrode sheet are stacked on top of each other. After the multiple foil electrodes are stacked, the metal strip electrodes and foil electrodes can be welded together, as well as the stacked foil electrodes can be welded together, using welding methods such as ultrasonic welding and laser welding.

[0003] However, errors are unavoidable in both the process of cutting foil tabs onto the electrode sheet and the process of winding the electrode sheet. After the electrode sheet is wound, misalignment may occur between the overlapping foil tabs. For example, misalignment may exist along the width direction of the foil tabs. Due to the misalignment of the foil tabs, the effective welding area between some tabs and the metal strip tabs is small, resulting in poor welding performance between the foil tabs and the metal strip tabs. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a method for manufacturing multi-tab battery cells, which can reduce the risk of misalignment between the welding areas of different foil tabs, thereby improving the welding quality of foil tabs and metal strip tabs.

[0005] The present invention also proposes an electrode sheet.

[0006] A method for manufacturing a multi-tab battery cell according to a first aspect of the present invention includes: stacking a plurality of foil tabs to form a foil tab group; cutting off both ends of the foil tab group along its width direction so that the width of the area to be welded of the foil tab group is the same as a preset width; and welding a metal strip tab to the remaining portion of the foil tab group.

[0007] The multi-tab battery cell manufacturing method according to the first aspect of the present invention has at least the following beneficial effects: the manufacturing method of the present invention can cut off both ends of the foil tab group along its own width direction, and the misaligned part of the foil tab can be cut off, thereby reducing the misalignment between the areas to be welded of the foil tab.

[0008] According to some embodiments of the present invention, a method for manufacturing a multi-tab battery cell includes: stacking multiple foil tabs to form a foil tab group; wherein the foil tab group includes a first stack and a second stack, the electrode includes an electrode body and the foil tabs connected to each other, the foil tab includes a narrow portion and a wide portion, the narrow portion is disposed between the wide portion and the electrode body, and both ends of the wide portion protrude relative to the narrow portion along the width direction of the foil tab, the first stack is formed by stacking multiple narrow portions, the second stack is formed by stacking multiple wide portions, and both ends of the second stack protrude relative to the first stack along the width direction of the foil tabs; cutting off both ends of the second stack along its own width direction, so that the width of the remaining part of the second stack is the same as a preset width; and welding a metal strip tab to the remaining part of the second stack.

[0009] According to some embodiments of the present invention, stacking multiple foil tabs to form a foil tab group includes: winding the electrode sheet so that multiple foil tabs of the same electrode sheet are stacked to form the foil tab group; wherein, one end of the electrode sheet body along its width direction is connected to the foil tab, multiple foil tabs are disposed at the same end of the electrode sheet body, and multiple foil tabs are spaced apart along the length direction of the electrode sheet body.

[0010] According to some embodiments of the present invention, stacking multiple foil tabs to form a foil tab group includes: stacking multiple electrodes to form a foil tab group by stacking multiple foil tabs belonging to different electrodes.

[0011] According to some embodiments of the present invention, cutting off both ends of the second composite body along its width direction includes: die-cutting the second composite body using a die-cutting tool; the die-cutting tool includes a clearance groove, the clearance groove having a rectangular cross-section, the width of the clearance groove being the same as the preset width, and the die-cutting tool including two cutting portions separated by the clearance groove; the die-cutting of the second composite body using the die-cutting tool includes: aligning the two cutting portions with the two ends of the second composite body respectively; moving the die-cutting tool along the thickness direction of the second composite body, so that the cutting portions cut off both ends of the second composite body.

[0012] According to some embodiments of the present invention, the two foil tabs with the smallest overlapping area in the foil tab group are respectively the first foil tab and the second foil tab. Along the width direction of the first foil tab, the edge of one end of the width portion of the first foil tab is the first edge, and along the width direction of the second foil tab, the edge of one end of the width portion of the second foil tab is the second edge. Along the thickness direction of the foil tab, the projection of the first edge falls on the second foil tab, and the projection of the second edge falls on the first foil tab. The portion of the second composite body located between the first edge and the second edge is the overlapping portion, and the portion of the second composite body located outside the overlapping portion is the misaligned portion. Cutting off both ends of the second composite body along its own width direction includes: cutting off the misaligned portion.

[0013] According to some embodiments of the present invention, the preset width is the same as the width of the narrow portion.

[0014] According to a second aspect of the present invention, an electrode sheet includes: an electrode sheet body; a foil tab, wherein one end of the electrode sheet body along its width direction is connected to the foil tab, the foil tab includes a narrow portion and a wide portion, the narrow portion is connected to the electrode sheet body, one end of the narrow portion away from the electrode sheet body is connected to the wide portion, and both ends of the wide portion protrude relative to the narrow portion along the length direction of the electrode sheet body.

[0015] The electrode sheet according to the second aspect of the present invention has at least the following beneficial effects: the electrode sheet can be used to process foil tab groups, which can reduce the risk of misalignment between the welding areas of different foil tabs.

[0016] According to some embodiments of the present invention, both the narrow portion and the wide portion are configured as rectangles.

[0017] According to some embodiments of the present invention, a plurality of foil tabs are provided, the plurality of foil tabs are connected to the same end of the electrode body, and the plurality of foil tabs are distributed at intervals along the length direction of the electrode body.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0020] Figure 1 This is a top view of an electrode sheet in the prior art;

[0021] Figure 2 for Figure 1A schematic diagram of the electrode after winding (top view);

[0022] Figure 3 for Figure 2 Enlarged view of region A in the middle;

[0023] Figure 4 This is a schematic diagram of a method for manufacturing a multi-pole battery cell according to an embodiment of the present invention;

[0024] Figure 5 This is a top view of the electrode sheet in one embodiment of the present invention;

[0025] Figure 6 for Figure 5 A schematic diagram of the electrode after winding (top view);

[0026] Figure 7 To Figure 6 A schematic diagram of the second composite after it has been cut;

[0027] Figure 8 To be Figure 7 A schematic diagram showing the foil electrode group and the metal strip electrode group after welding;

[0028] Figure 9 This is a schematic diagram of a die-cutting tool used for die-cutting foil tabs in one embodiment of the present invention;

[0029] Figure 10 for Figure 9 A schematic diagram of the die-cutting method using die-cutting tools;

[0030] Figure 11 This is a schematic diagram of the area to be removed from the foil tab group in another embodiment of the present invention.

[0031] Reference numerals: 100-Electrode sheet, 101-Electrode sheet body, 102-Foil electrode tab, 201-Foil electrode tab group, 202-Positive foil electrode tab group, 203-Negative foil electrode tab group, 301-Wide portion, 302-Narrow portion, 401-First stack, 402-Second stack, 403-Metal strip electrode tab, 501-Die-cutting tool, 502-Cutting portion, 503-Allowing groove, 601-Overlapping portion, 602-Misaligned portion, 603-First foil electrode tab, 604-Second foil electrode tab, 605-First edge, 606-Second edge. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0033] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0034] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0035] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0036] The welding between the foil tab 102 and the metal strip tab 403 in the prior art will be described below with reference to the accompanying drawings. Figure 1 The electrode 100 includes an electrode body 101 and multiple foil tabs 102, both of which are rectangular. Figure 1 and Figure 2 Multiple foil tabs 102 are stacked to form a foil tab group 201, which can then be soldered to a metal strip tab. Due to certain processing errors during the cutting of the foil tabs 102 or the stacking of multiple foil tabs 102, misalignment may occur between the stacked foil tabs 102 in the foil tab group 201. For example, the foil tabs 102 may be misaligned in their width direction (left-right direction); Figure 3 As shown, the edges of the lower foil tabs 102 may be exposed due to misalignment. When the foil tab group 201 is welded to the metal strip tab, the overlap area between some foil tabs 102 and the metal strip tab is small; therefore, after welding, the welding area between some foil tabs 102 and the metal strip tab is small.

[0037] The following describes the manufacturing method of the multi-pole battery cell of the present invention. In one embodiment, the manufacturing method includes the following steps:

[0038] S10: Stack multiple foil tabs 102 together to form a foil tab group 201;

[0039] S11: Cut off both ends of the foil tab group 201 along its own width direction so that the width of the area to be welded of the foil tab group 201 is the same as the preset width.

[0040] S12: Weld the metal strip tab 403 to the remaining portion of the foil tab group 201.

[0041] As mentioned above, due to the presence of errors, misalignment occurs between the foil tabs 102 in the foil tab group 201 obtained after step S10. However, in the manufacturing method of the present invention, by cutting off both ends of the foil tab group 201 along its width direction in step S11, the misaligned portions of the foil tabs 102 can be removed, thereby reducing the misalignment between the areas to be welded of the foil tabs 102. For example, refer to... Figure 10 The foil tab group 201 includes 6 foil tabs 102, which are misaligned in the left and right directions. The area between the dotted lines L1 and L2 is the remaining part of the foil tab group 201 (the distance between L1 and L2 in the left and right directions is the preset width). The parts of the foil tab group 201 located to the left of the dotted line L1 and to the right of the dotted line L2 will be cut off.

[0042] Furthermore, it should be noted that the stacked foil tabs 102 mentioned in this invention specifically refer to foil tabs 102 with the same polarity. For example, the positive foil tabs of the positive electrode are stacked with each other, the negative foil tabs of the negative electrode are stacked with each other, and the positive foil tabs and negative foil tabs are not stacked with each other.

[0043] In one embodiment, the foil tab 102 is configured as follows: Figure 5 As shown in the diagram. The electrode 100 includes an electrode body 101 and a foil tab 102 connected to each other. The foil tab 102 includes a narrow portion 302 and a wide portion 301. The narrow portion 302 is disposed between the wide portion 301 and the electrode body 101. Along the width direction of the foil tab 102, both ends of the wide portion 301 protrude relative to the narrow portion 302. (Refer to...) Figure 6 After stacking multiple foil tabs 102 to form a foil tab group 201, the foil tab group 201 includes a first stack 401 and a second stack 402. Both ends of the second stack 402 protrude relative to the first stack 401 along the width direction of the foil tabs 102. Accordingly, referring to… Figure 4 The manufacturing method of multi-electrode battery cells includes the following steps:

[0044] S20: Stack multiple foil tabs 102 to form a foil tab group 201; wherein, the foil tab group 201 includes a first stack 401 and a second stack 402, the first stack 401 is formed by stacking multiple narrow portions 302, and the second stack 402 is formed by stacking multiple wide portions 301, and both ends of the second stack 402 protrude relative to the first stack 401 along the width direction of the foil tabs 102;

[0045] S21: Cut off both ends of the second composite 402 so that the width of the remaining part of the second composite 402 is the same as the preset width.

[0046] S22: Weld the metal strip tab 403 to the remaining part of the second composite 402.

[0047] After completing step S21, the remaining portion of the second composite 402 (the portion still connected to the first composite 401) becomes the welding area of ​​the foil tab group 201, and the remaining portion of the wide portion 301 (the portion still connected to the narrow portion 302) becomes the welding area of ​​the foil tab 102. The manufacturing method of this embodiment can also reduce the misalignment between the welding areas of the foil tabs 102, and step S21 only cuts the second composite 402, making it less likely to damage the electrode body 101 of the electrode sheet 100 during the cutting process. Furthermore, it should be noted that after completing step S21 in this embodiment, the misalignment between the narrow portions 302 in the first composite 401 does not change, but the first composite 401 itself is not welded to the metal strip tab 403, and the misalignment between the narrow portions 302 does not affect the welding quality.

[0048] In step S11 or step S20, "stacking multiple foil tabs 102 together" can be achieved by winding the electrode 100 or by stacking the electrode 100 together.

[0049] The electrode 100 is wound to achieve the stacking of foil tabs 102, which is suitable for manufacturing wound cells with multi-tab designs. (Refer to...) Figure 5 The electrode 100 includes an electrode body 101 and multiple foil tabs 102. One end of the electrode body 101 along its width direction is connected to the foil tab 102. The foil tab 102 includes a narrow portion 302 and a wide portion 301. The two ends of the narrow portion 302 are connected to the electrode body 101 and the foil tab 102, respectively. Along the length direction of the electrode body 101, both ends of the wide portion 301 protrude relative to the narrow portion 302. Multiple foil tabs 102 are disposed at the same end of the electrode body 101 and are spaced apart along the length direction of the electrode body 101. After the electrode 100 is wound, multiple foil tabs 102 of the same electrode 100 will stack together to form a foil tab group 201. It should be noted that if Figure 5In this case, electrode 100 is the positive electrode. Therefore, when manufacturing a wound battery cell, the negative electrode, separator, and positive electrode are actually stacked together and then wound together. Figure 5 The shape of the positive electrode sheet is shown, and the negative foil tabs on the negative electrode sheet can also be stacked on top of each other; the foil tab group 201 formed by the stacking of positive foil tabs is the positive foil tab group 202, and the foil tab group 201 formed by the stacking of negative foil tabs is the negative foil tab group 203. In this invention, the length direction of the electrode body 101 is the same as the width direction of the foil tab 102 (both correspond to...). Figure 5 The width direction of the electrode body 101 is the same as the length direction of the foil electrode tab 102 (both correspond to the left and right directions). Figure 5 (the front and back directions in the middle).

[0050] Stacking multiple electrode sheets 100 together to achieve the stacking of foil tabs 102 is suitable for manufacturing stacked cells with multi-tab designs. In one embodiment, only one foil tab 102, including a wide portion 301 and a narrow portion 302, may be provided. In this configuration, stacking multiple electrode sheets 100 allows foil tabs 102 belonging to different electrode sheets 100 to be stacked together, thereby forming a foil tab group 201.

[0051] Reference Figure 5 In one embodiment, both the wide portion 301 and the narrow portion 302 can be rectangular, which can reduce the processing difficulty of the electrode 100.

[0052] In one embodiment, the cutting in step S11 or step S21 can be performed by die-cutting the foil tab group 201 using a die-cutting tool 501. The die-cutting tool 501 is as follows... Figure 9 As shown, the die-cutting tool 501 includes two cutting portions 502 and a clearance groove 503, which separates the two cutting portions 502. The clearance groove 503 has a rectangular cross-section and its width is the same as a preset width. Taking step S11 as an example, the two cutting portions 502 are first aligned with the two ends of the foil tab group 201 that need to be cut off, and then the die-cutting tool 501 moves along the thickness direction of the foil tab group 201 to cut off both ends of the foil tab group 201 along its width direction. (Refer to...) Figure 10Taking step S21 as an example, die-cutting the second composite 402 using the die-cutting tool 501 includes: aligning the two cutting portions 502 with the two ends of the second composite 402 respectively; moving the die-cutting tool 501 along the thickness direction of the second composite 402, causing the cutting portions 502 to cut off the two ends of the second composite 402. This process is equivalent to removing the two ends of the second composite 402. Since the foil tab group 201 to be cut includes multiple layers of foil tabs 102, compared with other cutting methods such as laser cutting, cutting with the die-cutting tool 501 is more efficient and produces better cutting results.

[0053] In one embodiment, the preset width can be set to be the same as the width of the narrow portion 302. In this way, after cutting off both ends of the second composite 402, the width of the second composite 402 is closer to the width of the first composite 401, and the shape of the foil tab group 201 is closer to a rectangle (viewed from a top angle), which facilitates the assembly of the cell with the aluminum-plastic film or other components in the battery.

[0054] To further reduce the misalignment between the foil tabs 102, in one embodiment, the step of cutting off both ends of the second stack 402 along its width direction specifically includes: cutting off the misaligned portion 602 of the foil tab group 201.

[0055] Can be combined Figure 11 The misaligned portion 602 is defined as follows: the two foil tabs 102 with the smallest overlapping area in the foil tab group 201 are the first foil tab 603 and the second foil tab 604, respectively. Along the width direction of the first foil tab 603, the edge of one end of the width portion 301 of the first foil tab 603 is the first edge 605. Along the width direction of the second foil tab 604, the edge of one end of the width portion 301 of the second foil tab 604 is the second edge 606. Along the thickness direction of the foil tab 102, the projection of the first edge 605 falls on the second foil tab 604, and the projection of the second edge 606 falls on the first foil tab 603. The portion of the second composite body 402 located between the first edge 605 and the second edge 606 is the overlapping portion 601, and the portion of the second composite body 402 located outside the overlapping portion 601 is the misaligned portion 602.

[0056] More specifically, with Figure 11For example, the foil tab group 201 includes six foil tabs 102. The overlap area between the second and third foil tabs 102 from top to bottom is the smallest. Let the second foil tab 102 be designated as the first foil tab 603, and the third foil tab 102 as the second foil tab 604. Then, the first edge 605 corresponds to the right edge of the width portion 301 of the first foil tab 603, and the second edge 606 corresponds to the left edge of the width portion 301 of the second foil tab 604. The portion of the second overlap 402 located between the first and second edges (i.e., the overlapping portion 601) is the portion of the second overlap 402 located between the dashed lines L3 and L4. The portion of the second overlap 402 outside the overlapping portion 601 (i.e., the misaligned portion 602) includes the portions of the second overlap 402 located to the left of the dashed line L3 and to the right of the dashed line L4.

[0057] The preset width can be set to be less than or equal to the width of the overlapping portion 601. If the preset width is equal to the width of the overlapping portion 601, then in step S21, the misaligned portion 602 can be cut off; if the preset width is less than the width of the overlapping portion 601, then in step S21, both the misaligned portion 602 and a portion of the overlapping portion 601 need to be cut off to satisfy the requirement that the width of the remaining part of the second composite 402 is equal to the preset width.

[0058] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A method for manufacturing a multi-tab battery cell, characterized in that, include: Multiple foil tabs are stacked to form a foil tab group; wherein, the foil tab group includes a first stack and a second stack, the electrode includes an interconnected electrode body and the foil tabs, the foil tab includes a narrow portion and a wide portion, the narrow portion is disposed between the wide portion and the electrode body, and both ends of the wide portion protrude relative to the narrow portion along the width direction of the foil tab, the first stack is formed by stacking multiple narrow portions, the second stack is formed by stacking multiple wide portions, and both ends of the second stack are protruding relative to the first stack along the width direction of the foil tab; Cut off both ends of the second composite body along its own width direction so that the width of the remaining part of the second composite body is the same as the preset width; Weld the metal strip tabs to the remaining portion of the second composite.

2. The method for manufacturing a multi-pole battery cell according to claim 1, characterized in that, The method of stacking multiple foil tabs to form a foil tab group includes: The electrode sheet is wound up so that multiple foil tabs of the same electrode sheet are stacked together to form the foil tab group; The electrode body is connected to the foil tab at one end along its width direction, and a plurality of foil tabs are disposed at the same end of the electrode body, and the plurality of foil tabs are distributed at intervals along the length direction of the electrode body.

3. The method for manufacturing a multi-pole battery cell according to claim 1, characterized in that, The method of stacking multiple foil tabs to form a foil tab group includes: Multiple electrodes are stacked together, and multiple foil tabs belonging to different electrodes are stacked together to form the foil tab group.

4. The method for manufacturing a multi-tab battery cell according to any one of claims 1 to 3, characterized in that, The step of cutting off both ends of the second composite body along its width direction includes: die-cutting the second composite body using a die-cutting tool; The die-cutting tool includes a clearance groove with a rectangular cross-section and a width that is the same as the preset width. The die-cutting tool includes two cutting portions separated by the clearance groove. The process of die-cutting the second composite material using a die-cutting tool includes: Align the two cut portions with the two ends of the second composite body, respectively. The die-cutting tool moves along the thickness direction of the second composite body, causing the cutting portion to cut off both ends of the second composite body.

5. The method for manufacturing a multi-pole battery cell according to claim 1, characterized in that, The two foil tabs with the smallest overlapping area in the foil tab group are the first foil tab and the second foil tab. Along the width direction of the first foil tab, the edge of one end of the width portion of the first foil tab is the first edge, and along the width direction of the second foil tab, the edge of one end of the width portion of the second foil tab is the second edge. Along the thickness direction of the foil tab, the projection of the first edge falls on the second foil tab, and the projection of the second edge falls on the first foil tab. The portion of the second composite body located between the first edge and the second edge is the overlapping portion, and the portion of the second composite body located outside the overlapping portion is the misaligned portion. The step of cutting off both ends of the second composite along its width direction includes: cutting off the misaligned portion.

6. The method for manufacturing a multi-tab battery cell according to claim 1, characterized in that, The preset width is the same as the width of the narrow section.

7. An electrode sheet, characterized in that, Manufactured by the multi-tab battery cell manufacturing method according to any one of claims 1 to 6, wherein the electrode comprises: Electrode body; A foil tab is provided, wherein one end of the electrode body along its width direction is connected to the foil tab, the foil tab includes a narrow portion and a wide portion, the narrow portion is connected to the electrode body, the end of the narrow portion away from the electrode body is connected to the wide portion, and both ends of the wide portion protrude relative to the narrow portion along the length direction of the electrode body.

8. The electrode sheet according to claim 7, characterized in that, Both the narrow portion and the wide portion are set as rectangles.

9. The electrode sheet according to claim 7, characterized in that, The foil tabs are provided in multiple ways, and the multiple foil tabs are connected to the same end of the electrode body. The multiple foil tabs are distributed at intervals along the length direction of the electrode body.

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