Multi-pole lug tab manufacturing method and battery cell manufacturing method

Abstract

The application provides a manufacturing method of a multi-tab tab sheet, which comprises the following steps: providing a tab sheet, wherein the tab sheet comprises a hollow foil area; and cutting the hollow foil area to form a plurality of quadrilateral structure tabs, so as to obtain a multi-tab tab sheet. According to the application, the hollow foil area of the tab sheet is cut to form the quadrilateral structure tabs, so that when the multi-tab tab sheet is wound to form a battery cell, the rolling pressure required for flattening the tabs can be reduced, the deformation of the multi-tab tab sheet is avoided, the shedding of active material on the positive and negative tab sheets is reduced, and the yield of the wound battery cell is greatly improved. The application also provides a manufacturing method of a battery cell.

Description

[0001] This application is a divisional application of application No. 202110536556.2, titled "Full-tab tab and wound battery", filed on May 17, 2021. TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to a manufacturing method of a multi-tab tab and a manufacturing method of a battery cell. BACKGROUND

[0003] With the development of electronic technology, lithium ion batteries have been widely used due to their high specific power, long cycle life, good safety performance, and no pollution. Traditional wound batteries are mainly single-tab or multi-tab wound batteries. Full-tab wound batteries are increasingly recognized due to their low internal resistance and high energy density. The manufacturing method of full-tab wound batteries is usually to coat active material on one end of the positive and negative tabs (this part coated with active material is called the coated area), and the other end is a blank part (i.e., not coated with active material, which is called a blank foil area). During the winding process of the positive and negative tabs (or after the winding of the positive and negative tabs is completed), the blank part is flattened to form a full tab.

[0004] During the inward folding of the above blank part, in order to flatten the tab, a relatively large pressure needs to be applied perpendicular to the surface of the tab (i.e., the two cylindrical end faces of the cylindrical battery formed after winding), which can easily cause the active material on the internal positive and negative tabs to fall off, and even cause the deformation of the internal tabs, greatly reducing the performance of the wound battery. SUMMARY

[0005] The purpose of the present application is to provide a manufacturing method of a multi-tab tab and a manufacturing method of a battery cell, which aims to solve the problems in the background art. By cutting the blank foil area of the tab to form a quadrilateral structure tab, when the multi-tab tab is wound to form a battery cell, the roller pressure required for flattening the tab can be reduced, thereby avoiding the deformation of the multi-tab tab, reducing the falling off of the active material on the positive and negative tabs, and greatly improving the yield of the wound battery cell. In addition, since a large pressure is not required when flattening the tab, the stress of the bent tab can be reduced, thereby ensuring the quality of the wound battery cell.

[0006] One embodiment of the present application provides a manufacturing method of a multi-tab tab, comprising:

[0007] providing a tab, the tab comprising a blank foil area;

[0008] cutting the blank foil area to form a plurality of quadrilateral structure tabs to obtain a multi-tab tab.

[0009] According to the purpose of the present application, all the hollow foil areas can be cut to form the tab ears of the quadrilateral structure, or part of the hollow foil areas can be cut to form the tab ears of the quadrilateral structure.

[0010] In an implementable manner, the hollow foil area is cut to form the tab ears of the quadrilateral structure.

[0011] The hollow foil area is cut by laser to form the tab ears of the quadrilateral structure.

[0012] In an implementable manner, the tab piece further comprises a coating area located on one side of the hollow foil area, the coating area is provided with an active substance, and the hollow foil area is not provided with an active substance.

[0013] In an implementable manner, the position where the hollow foil area meets the coating area forms a boundary line, the tab ear comprises a first side, a second side and a third side, the third side is located in the hollow foil area and close to the boundary line, the third side is parallel to the boundary line and the distance between the third side and the boundary line is less than 5mm; the first side and the second side are oppositely arranged, and both the first side and the second side intersect with the third side, the included angle between the first side and the third side is a, and the included angle a is an acute angle.

[0014] In an implementable manner, the included angle a is less than 60°.

[0015] In an implementable manner, the included angle a is less than 45°.

[0016] In an implementable manner, the tab ear further comprises a fourth side, the fourth side is oppositely arranged away from the boundary line and the third side, and the fourth side, the first side, the second side and the third side jointly constitute a quadrilateral.

[0017] In an implementable manner, the included angle between the first side and the fourth side is rounded, and / or the included angle between the second side and the fourth side is rounded.

[0018] In an implementable manner, the included angle between the second side and the third side is b, the included angle b is a right angle or an obtuse angle, and the sum of the included angle a and the included angle b is less than or equal to 180°.

[0019] In an implementable manner, the tab ear is a parallelogram structure.

[0020] In an implementable manner, a spacing is provided between every two adjacent tab ears, and the length of the spacing is 1 / 10 to 1 / 2 of the length of the tab ear.

[0021] In an implementable mode, the length of the interval is 1 / 5-1 / 3 of the length of the tab.

[0022] In an implementable mode, the ratio of the length to the width of each tab is (1-4):2.

[0023] In an implementable mode, the ratio of the length to the width of each tab is (1-3):2.

[0024] In an implementable mode, the ratio of the length to the width of each tab is 0.5:1.

[0025] Another embodiment of the present application also provides a manufacturing method of an electric core, comprising:

[0026] providing a multi-tab tab sheet manufactured by the manufacturing method of the multi-tab tab sheet as described above;

[0027] winding the multi-tab tab sheet to form the electric core.

[0028] In an implementable mode, during the winding of the multi-tab tab sheet to form the electric core, the tabs on the multi-tab tab sheet are folded and flattened towards the hole core of the electric core.

[0029] In actual operation, the folding or bending distance of each tab towards the hole core can be consistent or inconsistent; for example, all the tabs can be folded towards the hole core with the third edge or the interface line as the folding line to have a uniform folding or bending distance; or some tabs can be folded with the third edge or the interface line as the folding line, and the other tabs can be folded with the foil area at any position as the folding line.

[0030] In an implementable mode, the multi-tab tab sheet comprises a positive multi-tab tab sheet and a negative multi-tab tab sheet, and the electric core further comprises a diaphragm; the winding of the multi-tab tab sheet to form the electric core specifically comprises:

[0031] winding the positive multi-tab tab sheet, the negative multi-tab tab sheet and the diaphragm to form the electric core.

[0032] In an implementable mode, the distance between the tabs on the positive multi-tab tab sheet and the top end of the diaphragm after flattening is 0.5-5 mm, and the distance between the tabs on the negative multi-tab tab sheet and the bottom end of the diaphragm after flattening is less than 5 mm.

[0033] In an implementable mode, the distance between the tabs on the positive multi-tab tab sheet and the top end of the diaphragm after flattening is 0.5-3 mm, and the distance between the tabs on the negative multi-tab tab sheet and the bottom end of the diaphragm after flattening is less than 3 mm.

[0034] In an implementable mode, the battery cell is a cylindrical battery cell.

[0035] In an implementable mode, the tab further comprises a coating area, the coating area is located at one side of the hollow foil area, a position where the hollow foil area and the coating area meet forms a junction line, the tab ear comprises a first edge, a second edge and a third edge, the third edge is located in the hollow foil area and close to the junction line, the third edge is parallel to the junction line and the distance between the third edge and the junction line is less than 5mm; the first edge and the second edge are oppositely arranged, and the first edge and the second edge both intersect with the third edge, an included angle between the first edge and the third edge is a, the included angle a is an acute angle; the winding direction of the multi-tab tab during winding is the same as the direction of the included angle a.

[0036] The manufacturing method of the multi-tab tab provided by the application cuts the hollow foil area of the tab to form a tab ear with a quadrilateral structure, and in the process of winding the multi-tab tab to form a battery cell, the tab ear is folded and flattened towards the hole core during the winding of the multi-tab tab, which can effectively reduce the rolling pressure required when the tab ear is flattened, thereby avoiding deformation of the multi-tab tab and reducing the shedding of active materials on the tab, greatly improving the yield of the wound battery cell. In addition, since a large pressure is not required when the tab ear is flattened, the stress of the folded tab ear can be reduced, thereby ensuring the quality of the wound battery cell. The wound battery cell manufactured by the multi-tab tab not only has a simple design scheme, but also has good electrical performance, high yield and strong practicality. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 FIG. 1 is a structural schematic diagram of the tab before cutting in the first embodiment of the application.

[0038] Figure 2 FIG. 2 is a structural schematic diagram of the multi-tab tab in the first embodiment of the application.

[0039] Figure 3 FIG. 3 is a structural schematic diagram of the single tab ear in the first embodiment of the application. Figure 2 FIG. 4 is an enlarged schematic diagram of the position A in FIG. 3.

[0040] Figure 4 FIG. 5 is a structural schematic diagram of the battery cell in the first embodiment of the application. Figure 3 FIG. 6 is a structural schematic diagram of the single tab ear in the second embodiment of the application.

[0041] Figure 5 FIG. 7 is a structural schematic diagram of the battery cell in the second embodiment of the application.

[0042] Figure 6 FIG. 8 is a top view of the battery cell in the second embodiment of the application. Figure 5 FIG. 9 is a bottom view of the battery cell in the second embodiment of the application.

[0043] Figure 7 FIG. 10 is a structural schematic diagram of the battery cell in the third embodiment of the application. Figure 5 FIG. 11 is a structural schematic diagram of the battery cell in the third embodiment of the application. FIG. 12 is a structural schematic diagram of the battery cell in the third embodiment of the application.

[0044] Figure 8 As shown in FIG. 1, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the first embodiment of the present application. Figure 5 As shown in FIG. 2, the structure of the negative electrode tab is shown in the structure diagram of the negative electrode tab in the first embodiment of the present application.

[0045] Figure 9 As shown in FIG. 3, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the second embodiment of the present application. Figure 5 As shown in FIG. 4, the structure of the negative electrode tab is shown in the structure diagram of the negative electrode tab in the second embodiment of the present application.

[0046] Figure 10 As shown in FIG. 5, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the third embodiment of the present application.

[0047] Figure 11 As shown in FIG. 6, the structure of the negative electrode tab is shown in the structure diagram of the negative electrode tab in the third embodiment of the present application.

[0048] Figure 12 As shown in FIG. 7, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the fourth embodiment of the present application.

[0049] Figure 13 As shown in FIG. 8, the structure of the negative electrode tab is shown in the structure diagram of the negative electrode tab in the fourth embodiment of the present application.

[0050] Figure 14 As shown in FIG. 9, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the fifth embodiment of the present application. DETAILED DESCRIPTION

[0051] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0052] The terms "first", "second", "third", "fourth" and the like (if any) in the description and claims of the present application are used to distinguish similar objects, and do not necessarily have to be described in a specific order or sequence.

[0053] The terms "up", "down", "left", "right", "front", "back", "top", "bottom" and the like (if any) in the description and claims of the present application are defined by the position of the structure in the drawing and the position of the structure relative to each other, only to express the technical solution clearly and conveniently. It should be understood that the use of the terms should not limit the scope of the application claimed.

[0054] As shown in FIG. 1, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the first embodiment of the present application. Figures 1 to 4 As shown in FIG. 2, the structure of the negative electrode tab is shown in the structure diagram of the negative electrode tab in the first embodiment of the present application. Figure 1 As shown in FIG. 3, the structure of the positive electrode tab is shown in the structure diagram of the positive electrode tab in the second embodiment of the present application. Figure 2 As shown in FIG. 4, the structure of the negative electrode tab is shown in the structure diagram of the negative electrode tab in the second embodiment of the present application.

[0055] The tab is provided, and the tab includes a hollow foil area 12.

[0056] The empty foil area 12 is cut to form a plurality of four-angled structure tab 14 to obtain the multi-tab tab 1.

[0057] As an embodiment, the empty foil area 12 is cut to form a plurality of four-angled structure tab 14, specifically including:

[0058] The empty foil area 12 is cut by laser to form a plurality of four-angled structure tab 14.

[0059] As shown in Figure 1 and Figure 2 , as an embodiment, the tab further includes a coating area 11, the coating area 11 is located on one side of the empty foil area 12, the coating area 11 is coated with active material, and the empty foil area 12 is not coated with active material.

[0060] Specifically, as shown in Figure 1 and Figure 2 , the tab is a rectangular structure before cutting, the tab has a length direction X and a width direction Y, the coating area 11 and the empty foil area 12 are arranged on both sides of the tab along the width direction Y, and a plurality of tabs 14 are arranged in sequence along the length direction X of the tab.

[0061] As shown in Figures 1 to 4 , as an embodiment, the position where the empty foil area 12 meets the coating area 11 forms a boundary line 13, the four edges of the tab 14 include a first edge 141, a second edge 142 and a third edge 143, the third edge 143 is located in the empty foil area 12 and close to the boundary line 13, the third edge 143 is parallel to the boundary line 13 and the distance between the third edge 143 and the boundary line 13 is less than 5mm. The first edge 141 and the second edge 142 are oppositely arranged, and both the first edge 141 and the second edge 142 intersect with the third edge 143. When the distance between the third edge 143 and the boundary line 13 is 0mm, the third edge 143 coincides with the boundary line 13. The included angle between the first edge 141 and the third edge 143 is a, and the included angle a is an acute angle.

[0062] Specifically, the multi-tab tab 1 includes a positive multi-tab tab 21 and a negative multi-tab tab 22 (the structure of the positive multi-tab tab 21 and the negative multi-tab tab 22 can be referred to Figure 5 , Figure 8 and Figure 9 ), the winding direction S of the multi-tab tab 1 when winding to form the battery cell 2 is the same as the direction of the acute angle a. As shown in Figure 5 , the winding direction S of the positive multi-tab tab 21 and the negative multi-tab tab 22 is from Figure 5In the counterclockwise direction, the acute angle a of the positive multi-tab tab 21 and the negative multi-tab tab 22 is in the same direction as the winding direction S during winding. In this embodiment, the tab 14 is arranged in a quadrilateral structure, and the included angle a between the first edge 141 and the third edge 143 is an acute angle. During winding of the multi-tab tab 1 to form the battery cell 2, the winding direction S of the multi-tab tab 1 is consistent with the direction of the acute angle a, and the multi-tab tab 1 is folded and flattened to the hole core 20 while winding, which can effectively reduce the rolling pressure required when flattening the tab 14, thereby avoiding deformation of the coated area 11 of the multi-tab tab 1, reducing the shedding of active materials on the multi-tab tab 1, and greatly improving the yield of the wound battery cell 2.

[0063] As shown in Figure 3 and Figure 4 , as an embodiment, the included angle a is less than 60°.

[0064] As another embodiment, the included angle a is less than 45°.

[0065] As shown in Figure 3 , as an embodiment, the four edges of the tab 14 further include a fourth edge 144, which is arranged away from the boundary line 13 and opposite to the third edge 143. The fourth edge 144, the first edge 141, the second edge 142 and the third edge 143 together form a quadrilateral.

[0066] As shown in Figure 3 , as an embodiment, the third edge 143 coincides with the boundary line 13, and the fourth edge 144 is parallel to the third edge 143.

[0067] Of course, the third edge 143 can also not coincide with the boundary line 13. As shown in Figure 13 , as an embodiment, the third edge 143 is spaced apart from the boundary line 13, and the space foil area 12 between the third edge 143 and the boundary line 13 is a parallelogram structure. As shown in Figure 14 , as another embodiment, the third edge 143 is spaced apart from the boundary line 13, and the space foil area 12 between the third edge 143 and the boundary line 13 is a rectangular structure.

[0068] As shown in Figure 12 , as an embodiment, the included angle between the first edge 141 and the fourth edge 144 is rounded, and the included angle between the second edge 142 and the fourth edge 144 is also rounded. After rounding, the intersection of the two edges is a smooth transition, which is more conducive to reducing the pressure required for flattening the tab 14; and reducing the sharp end discharge.

[0069] As shown in Figure 3As shown, in one embodiment, the included angle formed between the second side 142 and the third side 143 is b, and the included angle b is a right angle or an obtuse angle. The sum of the included angle a and the included angle b is less than or equal to 180°.

[0070] like Figure 3 As shown, in one embodiment, the included angle b is an obtuse angle, and the sum of the included angles a and b is equal to 180°. That is, in this embodiment, the tab 14 is a parallelogram structure.

[0071] like Figures 2 to 4 As shown, in one embodiment, there is a gap between every two adjacent tabs 14, and the length N of the gap is 1 / 10 to 1 / 2 of the length L of the tab 14 (i.e. the length of the third side 143 or the fourth side 144).

[0072] In another implementation, the length N of the interval is 1 / 5 to 1 / 3 of the length L of the tab 14.

[0073] like Figure 4 As shown, in one embodiment, the ratio of the length L to the width W of each tab 14 is (1-4):2.

[0074] In another implementation, the ratio of the length L to the width W of each tab 14 is (1-3):2.

[0075] In another implementation, the ratio of the length L to the width W of each tab 14 is 0.5:1.

[0076] Of course, in other embodiments, the tab 14 can also be other shapes, such as a trapezoidal structure. Figure 10 As shown, the angle formed between the first side 141 and the third side 143 is an acute angle, and the angle formed between the second side 142 and the third side 143 is a right angle, meaning that the tab 14 is a right trapezoidal structure. Furthermore, looking from left to right, in every two adjacent tabs 14, the second side 142 of the preceding tab 14 is connected to the first side 141 of the following tab 14 near the boundary line 13 (i.e., there is no gap between them). Since the tab 14 is a trapezoidal structure, the second side 142 of the preceding tab 14 at the end furthest from the boundary line 13 and the first side 141 of the following tab 14 at the end furthest from the boundary line 13 are spaced apart, and the length N of this interval is 1 / 10 to 1 / 2 of the length of the third side 143.

[0077] like Figure 11As shown in the drawings, in another embodiment, the included angle between the first side 141 and the third side 143 is an acute angle, the included angle between the second side 142 and the third side 143 is an obtuse angle, and the sum of the acute angle and the obtuse angle is less than 180°, that is, the tab 14 is an obtuse trapezoidal structure. At the same time, from left to right, in every two adjacent tabs 14, the second side 142 of the front tab 14 at one end close to the boundary line 13 is connected to the first side 141 of the rear tab 14 at one end close to the boundary line 13 (that is, no interval between the two), and since the tab 14 is a trapezoidal structure, the second side 142 of the front tab 14 at one end away from the boundary line 13 is spaced apart from the first side 141 of the rear tab 14 at one end away from the boundary line 13, and the length N of the interval is 1 / 10-1 / 2 of the length of the third side 143.

[0078] As shown in the drawings, Figures 5 to 9 The application also provides a manufacturing method of the battery cell, which comprises:

[0079] providing a multi-tab tab sheet 1 prepared by the manufacturing method of the multi-tab tab sheet described above;

[0080] winding the multi-tab tab sheet 1 to form the battery cell 2.

[0081] As an implementation form, in the process of winding the multi-tab tab sheet 1 to form the battery cell 2, the tabs 14 on the multi-tab tab sheet 1 are folded and flattened towards the hole core 20 of the battery cell 2.

[0082] It should be noted that according to the actual operation process, the folding or bending distance of each tab 14 towards the hole core 20 can be consistent or inconsistent; for example, all tabs 14 can be folded towards the hole core 20 with the third side 143 or the boundary line 13 as the folding line to have a uniform folding or bending distance; or part of the tabs 14 can be folded with the third side 143 or the boundary line 13 as the folding line, and the other tabs 14 can be folded with an arbitrary position of the empty foil area as the folding line, etc.

[0083] As shown in the drawings, Figure 5 As an implementation form, the multi-tab tab sheet 1 comprises a positive multi-tab tab sheet 21 and a negative multi-tab tab sheet 22, and the battery cell 2 further comprises a separator 23; the winding of the multi-tab tab sheet 1 to form the battery cell 2 specifically comprises:

[0084] winding the positive multi-tab tab sheet 21, the negative multi-tab tab sheet 22 and the separator 23 after being laminated, and in the winding process, the tabs 14 on the positive multi-tab tab sheet 21 and the tabs 14 on the negative multi-tab tab sheet 22 are folded and flattened towards the hole core 20 of the battery cell 2.

[0085] Specifically, the diaphragm 23 includes a first diaphragm 231 and a second diaphragm 232, the first diaphragm 231 is clamped between the positive multi-tab tab 21 and the negative multi-tab tab 22, and the second diaphragm 232 is located outside the positive multi-tab tab 21 or the negative multi-tab tab 22, that is, the positive multi-tab tab 21, the first diaphragm 231, the negative multi-tab tab 22 and the second diaphragm 232 are sequentially stacked, and the four are formed into a cylindrical battery cell 2 after being stacked. The tabs 14 on the positive multi-tab tab 21 and the tabs 14 on the negative multi-tab tab 22 are respectively located at both ends of the battery cell 2. As shown in Figure 6 and Figure 7 After the winding and flattening of the tabs 14 are completed, the tabs 14 on the positive multi-tab tab 21 and the tabs 14 on the negative multi-tab tab 22 are respectively stacked to form a circular ring.

[0086] Specifically, in the process of making the battery cell 2, the positive multi-tab tab 21 and the negative multi-tab tab 22 are first coated by a coating machine to ensure that the positive multi-tab tab 21 and the negative multi-tab tab 22 are both formed with a blank foil area; then the blank foil area of the positive multi-tab tab 21 and the negative multi-tab tab 22 is cut by laser to form a plurality of quadrilateral tabs 14; then the positive multi-tab tab 21, the negative multi-tab tab 22 and the diaphragm 23 are wound into a cylindrical shape, and the tabs 14 are folded and flattened towards the hole core 20 during the winding process.

[0087] As shown in Figure 5 As an embodiment, the distance between the tabs 14 on the positive multi-tab tab 21 and the top end of the diaphragm 23 after flattening is 0.5-5mm, and the distance between the tabs 14 on the negative multi-tab tab 22 and the bottom end of the diaphragm 23 after flattening is less than 5mm.

[0088] As another embodiment, the distance between the tabs 14 on the positive multi-tab tab 21 and the top end of the diaphragm 23 after flattening is 0.5-3mm, and the distance between the tabs 14 on the negative multi-tab tab 22 and the bottom end of the diaphragm 23 after flattening is less than 3mm.

[0089] As an embodiment, the multi-tab tab 1 is wound to form a cylindrical battery cell, that is, the above-mentioned battery cell 2 is a cylindrical battery cell.

[0090] As an embodiment, the winding direction S of the multi-tab tab 1 during winding is the same as the direction of the included angle a.

[0091] Specifically, as shown in Figure 5 Figure 8 Figure 9 ​​As shown, the orientation of the acute angle on the tab 14 of the positive multi-tab tab 21 and the orientation of the acute angle on the tab 14 of the negative multi-tab tab 22 are both the same as the winding direction S. During the winding process of the battery cell 2, the tab 14 is flattened towards the hole core 20 by winding the positive and negative multi-tab tabs 21 / 22, which can effectively reduce the rolling pressure required when flattening the tab 14, thereby avoiding deformation of the positive and negative multi-tab tabs 21 / 22 and reducing shedding of active material on the positive and negative multi-tab tabs 21 / 22, greatly improving the yield of the wound battery cell 2.

[0092] As shown in FIG. 1, the multi-tab tab 1 is wound to form a battery cell 2. The multi-tab tab 1 includes a positive multi-tab tab 21 and a negative multi-tab tab 22. The positive multi-tab tab 21 includes a plurality of tabs 14, and the negative multi-tab tab 22 also includes a plurality of tabs 14. The tabs 14 of the positive multi-tab tab 21 and the tabs 14 of the negative multi-tab tab 22 are arranged in a four-sided structure. Figure 8 Figure 9 As shown, as an embodiment, the tabs 14 of the positive multi-tab tab 21 and the tabs 14 of the negative multi-tab tab 22 are both chamfered, and the intersection of the two sides after chamfering is a smooth transition, which is more conducive to reducing the pressure required for flattening the tab 14 and reducing the sharp end discharge.

[0093] The multi-tab tab and the manufacturing method of the battery cell provided by the embodiment of the present application set the tab 14 in a four-sided structure, and the included angle a between the first side 141 and the third side 143 of the tab 14 is an acute angle. During the winding process of the multi-tab tab 1 to form the battery cell 2, the winding direction S of the multi-tab tab 1 is consistent with the orientation of the acute angle, and the tab 14 is flattened towards the hole core 20 by winding the multi-tab tab 1, which can effectively reduce the rolling pressure required when flattening the tab 14, thereby avoiding deformation of the multi-tab tab 1 and reducing shedding of active material on the multi-tab tab 1, greatly improving the yield of the wound battery cell 2. In addition, since a large pressure is not required when flattening the tab 14, the stress of bending the tab 14 can be reduced, thereby ensuring the quality of the wound battery cell 2. The wound battery cell 2 made of the multi-tab tab 1 not only has a simple design scheme, but also has good electrical performance, high yield, and strong practicality.

[0094] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.​

Claims

1. A method for manufacturing a multi-electrode tab, characterized in that, include: An electrode is provided, the electrode comprising an empty foil area (12) and a coated area (11), the coated area (11) being located on one side of the empty foil area (12), the coated area (11) being provided with an active substance, the empty foil area (12) being not provided with an active substance, and the position where the empty foil area (12) and the coated area (11) meet forms a boundary line (13). Multiple quadrilateral-shaped tabs (14) are formed by cutting the empty foil area (12) to obtain a multi-tab electrode sheet (1); wherein, the tab (14) includes a first side (141), a second side (142), a third side (143) and a fourth side (144), the third side (143) is located in the empty foil area (12) and close to the boundary line (13), the third side (143) does not coincide with the boundary line (13), the third side (143) and the boundary line (13) are spaced apart from each other, the third side (143) is parallel to the boundary line (13) and the distance between the third side (143) and the boundary line (13) is less than 5. mm, at least part of the tab (14) uses the third side (143) as a fold line; the first side (141) and the second side (142) are arranged opposite each other, and both the first side (141) and the second side (142) intersect the third side (143); the included angle formed between the first side (141) and the third side (143) is α, the included angle α is an acute angle, the included angle α is less than 60°, the included angle formed between the second side (142) and the third side (143) is b, the included angle b is an obtuse angle, the sum of the included angle α and the included angle b is equal to 180°, the tab (14) is a parallelogram structure; the fourth side (144) is away from the boundary line (13). And it is arranged opposite to the third side (143), the angle formed by the first side (141) and the fourth side (144) is rounded, and / or the angle formed by the second side (142) and the fourth side (144) is rounded; there is a gap between every two adjacent tabs (14), the length (N) of the gap is 1 / 10 to 1 / 2 of the length (L) of the tab (14); the ratio of the length (L) to the width (W) of each tab (14) is (1~4):2; the winding direction (S) of the multi-tab electrode (1) during winding is the same as the direction of the included angle a, and after the multiple tabs (14) are folded and flattened, the positions of the adjacent tabs (14) can overlap each other.

2. The method for manufacturing the multi-electrode tab as described in claim 1, characterized in that, The process of forming multiple quadrilateral-shaped tabs (14) by cutting the empty foil area (12) specifically includes: The tabs (14) are formed by laser cutting of the empty foil area (12) into multiple quadrilateral structures.

3. The method for manufacturing the multi-electrode tab as described in claim 1, characterized in that, The included angle α is less than 45°.

4. The method for manufacturing the multi-electrode tab as described in claim 1, characterized in that, The length (N) of the interval is 1 / 5 to 1 / 3 of the length (L) of the tab (14).

5. The method for manufacturing the multi-electrode tab as described in claim 1, characterized in that, The ratio of the length (L) to the width (W) of each of the tabs (14) is (1~3):

2.

6. The method for manufacturing the multi-electrode tab as described in claim 5, characterized in that, The ratio of the length (L) to the width (W) of each of the tabs (14) is 0.5:

1.

7. A method for manufacturing a battery cell, characterized in that, include: A multi-pole tab (1) is provided, which is prepared by the method of manufacturing a multi-pole tab as described in any one of claims 1-6. The multi-pole electrode (1) is wound to form a battery cell (2).

8. The method for manufacturing a battery cell as described in claim 7, characterized in that, During the process of winding the multi-tab electrode (1) to form the battery cell (2), the tabs (14) on the multi-tab electrode (1) are folded and smoothed towards the core (20) of the battery cell (2).

9. The method for manufacturing a battery cell as described in claim 7, characterized in that, The multi-electrode sheet (1) includes a positive multi-electrode sheet (21) and a negative multi-electrode sheet (22), and the battery cell (2) further includes a separator (23); the process of forming the battery cell (2) by winding the multi-electrode sheet (1) specifically includes: The positive electrode multi-pole tab (21), the negative electrode multi-pole tab (22) and the diaphragm (23) are stacked together and then wound to form the battery cell (2).

10. The method for manufacturing a battery cell as described in claim 9, characterized in that, The distance between the tabs (14) on the positive electrode multi-tab plate (21) and the top of the diaphragm (23) after smoothing is 0.5-5mm, and the distance between the tabs (14) on the negative electrode multi-tab plate (22) and the bottom of the diaphragm (23) after smoothing is less than 5mm.

11. The method for manufacturing a battery cell as described in claim 10, characterized in that, The distance between the tabs (14) on the positive electrode multi-tab plate (21) and the top of the diaphragm (23) after smoothing is 0.5-3mm, and the distance between the tabs (14) on the negative electrode multi-tab plate (22) and the bottom of the diaphragm (23) after smoothing is less than 3mm.

12. The method for manufacturing a battery cell according to any one of claims 7-11, characterized in that, The battery cell (2) is a cylindrical battery cell.

13. The method for manufacturing a battery cell according to any one of claims 7-11, characterized in that, The electrode also includes a coating area (11), which is located on one side of the empty foil area (12). The empty foil area (12) and the coating area (11) are connected to form a boundary line (13). The electrode tab (14) includes a first side (141), a second side (142), and a third side (143). The third side (143) is located in the empty foil area (12) and close to the boundary line (13). The third side (143) is parallel to the boundary line (13) and the distance between the third side (143) and the boundary line (13) is less than 5. mm; the first side (141) and the second side (142) are arranged opposite to each other, and both the first side (141) and the second side (142) intersect the third side (143). The included angle formed between the first side (141) and the third side (143) is α, and the included angle α is an acute angle; the winding direction (S) of the multi-pole tab (1) during winding is the same as the direction of the included angle α.

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