Tab pole piece and winding battery
By arranging the pole tabs into a quadrilateral structure and forming sharp angles, the problem of high pressure when smoothing the pole tabs of traditional rolled batteries is solved, reducing pole piece deformation and material shedding, and improving battery yield and quality.
Patent Information
- Application Number
- CN202290000450.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2021-05-17
- Filing Date
- 2022-05-13
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2032-05-13
AI Technical Summary
Traditional all-pole ear rolling batteries require greater pressure in the process of smoothing the electrode ears, which can easily cause the active material on the electrode sheet to fall off and the electrode sheet to deform, reducing the battery's performance.
Set the pole tab into a quadrilateral structure. The angle a formed between the first side and the third side is an acute angle. The winding direction is consistent with the direction of the angle a. By winding the tab pole piece, fold it towards the hole core. Smooth the ears.
It reduces the roller pressure required to smooth the tabs, avoids the deformation of the tab tabs and the shedding of active materials, improves the yield rate of the full tab wound battery core, and ensures the quality of the battery.
Smart Images
Figure CN222380806U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and in particular to a pole tab and a wound battery. Background Art
[0002] 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-pole or multi-pole wound batteries, and full-pole wound batteries are increasingly recognized due to their low internal resistance and high energy density.
[0003] The manufacturing method of full-tab wound batteries is usually to coat one end of the positive and negative electrodes with active materials (the portion coated with active materials is called the coating area), and the other end is a blank portion (that is, not coated with active materials, and this portion is called the empty foil area). During the winding process of the positive and negative electrodes (or after the winding of the positive and negative electrodes is completed), the blank portion is smoothed to form a full tab.
[0004] In the process of folding the blank part inward, in order to smooth the ear, it is usually necessary to apply a large pressure on the surface perpendicular to the electrode sheet (i.e., the two cylindrical end faces of the cylindrical battery formed after winding), which can easily cause the active materials on the internal positive and negative electrode sheets to fall off, and even cause deformation of the internal electrode sheets, greatly reducing the performance of the wound battery. Utility Model Content
[0005] The purpose of the present application is to provide a pole ear, pole piece and wound battery, aiming to solve the shortcomings of the above-mentioned background technology, by setting the pole ear into a quadrilateral structure and the angle a formed between the first side and the third side is an acute angle, so that when the winding direction is the same as the direction of the angle a, the roller pressure required for smoothing the pole ear can be reduced, thereby avoiding the deformation of the pole ear pole piece, while reducing the shedding of active materials on the positive and negative pole pieces, greatly improving the yield rate of the full-pole ear wound battery cell. In addition, since a lot of pressure is not required when smoothing the pole ear, the stress of the bent pole ear can be reduced, thereby ensuring the quality of the wound battery. The wound battery is not only simple in design, but also has good electrical performance, high yield and strong practicality.
[0006] An embodiment of the present application provides a tab pole piece, comprising a coating area and a hollow foil area located on one side of the coating area, wherein the position where the hollow foil area meets the coating area forms a junction line, wherein the hollow foil area is cut to form a plurality of tabs of quadrilateral structure, wherein the plurality of tabs are arranged in sequence along the length direction of the tab pole piece, wherein the four sides of each tab include a first side, a second side and a third side, wherein the third side is located in the hollow foil area and close to the junction line, wherein the third side is parallel to the junction line and the distance from the junction line is less than 5 mm; wherein the first side and the second side are arranged opposite to each other, and the first side and the second side both intersect with the third side, and the angle formed between the first side and the third side is a, and the angle a is an acute angle. Or the third side is located in the hollow foil area and close to the junction line, wherein the third side is parallel to the junction line and the distance from the junction line is less than 3 mm.
[0007] According to the purpose of the present application, all of the empty foil areas may be cut to form a plurality of electrode tabs with a quadrilateral structure, or part of the empty foil areas may be cut to form a plurality of electrode tabs with a quadrilateral structure.
[0008] According to the actual operation process, the bending or folding distance of each pole ear toward the hole core can be consistent or inconsistent; for example, all pole ears can be folded toward the hole core with the third side or the boundary line as the folding line to have a uniform bending or folding distance; some pole ears can also be folded with the third side or the boundary line as the folding line, and other pole ears can be folded with any position of the empty foil area as the folding line, etc.
[0009] In one achievable manner, the pole tab pole sheet is a positive pole tab pole sheet and / or a negative pole tab pole sheet, and the winding direction of the pole tab pole sheet is the same as the direction of the angle a.
[0010] In one achievable manner, the four sides of each of the pole ears further include a fourth side, the fourth side is away from the boundary line and arranged opposite to the third side, and the fourth side together with the first side, the second side and the third side form a quadrilateral.
[0011] In one practicable manner, the angle formed between the second side and the fourth side is rounded; and / or the angle formed between the first side and the fourth side is rounded. After the rounding, the intersection of the two sides is a smooth transition, which is more conducive to reducing the pressure required to smooth the tab; and reducing tip discharge.
[0012] In an achievable manner, the angle a is less than 60°; or the angle a is less than 45°. This angle range is more conducive to reducing the pressure required to smooth the tab.
[0013] In one achievable manner, the angle formed between the second side and the third side is b, the angle b is a right angle or an obtuse angle, and the sum of the angle a and the angle b is less than or equal to 180°.
[0014] In one achievable manner, the pole ear is a parallelogram structure.
[0015] In one achievable manner, a space is provided between every two adjacent pole lugs, and the length of the space is 1 / 100 to 1; or 1 / 10 to 1 / 2; or 1 / 5 to 1 / 3 of the length of the pole lug.
[0016] In one achievable manner, the length of the interval is 0.1 mm to 10 mm; or 1 mm to 4 mm; or 0.1 mm to 1 mm; or 5 mm to 8 mm.
[0017] In one achievable manner, the ratio of the length to the width of each of the tabs is (1-4):2; or (1-3):2 or 0.5:1.
[0018] Another embodiment of the present application further provides a wound battery, comprising a positive pole tab pole sheet and a negative pole tab pole sheet, wherein the positive pole tab pole sheet and / or the negative pole tab pole sheet are the pole tab pole sheets described above.
[0019] In one feasible manner, the wound battery also includes a first diaphragm, which is sandwiched between the positive pole tab pole sheet and the negative pole tab pole sheet. The positive pole tab pole sheet, the first diaphragm and the negative pole tab pole sheet are stacked and wound to form a battery cell, and the tabs on the positive pole tab pole sheet and the tabs on the negative pole tab pole sheet are respectively located at both ends of the battery cell.
[0020] In one achievable manner, the distance that the tab on the positive electrode tab pole piece protrudes from the top of the first diaphragm after being smoothed is 0.5-5 mm, and the distance that the tab on the negative electrode tab pole piece protrudes from the bottom of the first diaphragm after being smoothed is less than 5 mm.
[0021] The pole ear pole piece provided by the present application sets the pole ear into a quadrilateral structure, and the angle formed between the first side and the third side is an acute angle. In the process of winding the pole ear pole piece to form a battery cell, the winding direction of the pole ear pole piece is consistent with the direction of the acute angle. By winding the pole ear pole piece and folding and smoothing the pole ear toward the hole core, the roller pressure required for smoothing the pole ear can be effectively reduced, thereby avoiding the deformation of the pole ear pole piece, and reducing the shedding of active materials on the pole piece, greatly improving the yield rate of the full pole ear wound battery cell. In addition, since a lot of pressure is not required when smoothing the pole ear, the stress of the bent pole ear can be reduced, thereby ensuring the quality of the wound battery. The wound battery not only has a simple design, but also has good electrical performance, high yield, and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is a schematic diagram of the structure when the pole tab and pole piece have not been cut in the first embodiment of the present application.
[0023] Figure 2 This is a schematic diagram of the structure of the pole tab and pole piece after cutting in the first embodiment of the present application.
[0024] Figure 3 for Figure 2 Enlarged schematic diagram of the structure at position A in the middle.
[0025] Figure 4 for Figure 3 Schematic diagram of the structure of a single pole ear.
[0026] Figure 5 It is a schematic diagram of the three-dimensional structure of the wound battery in the first embodiment of the present application.
[0027] Figure 6 for Figure 5 Top view of the .
[0028] Figure 7 for Figure 5 Bottom view of .
[0029] Figure 8 for Figure 5 Schematic diagram of the structure of the positive pole tab pole piece.
[0030] Fig. 9 for Figure 5 Schematic diagram of the structure of the middle negative electrode tab.
[0031] Fig.10 It is a schematic diagram of the structure of the pole tab and pole piece in the second embodiment of the present application.
[0032] Fig.11 It is a schematic diagram of the structure of the pole tab and pole piece in the third embodiment of the present application.
[0033] Fig.12 It is a schematic diagram of the structure of the pole tab and pole piece in the fourth embodiment of the present application.
[0034] Fig.13 It is a schematic diagram of the structure of the pole tab and pole piece in the fifth embodiment of the present application.
[0035] Fig.14 It is a schematic diagram of the structure of the pole tab and pole piece in the sixth embodiment of the present application. DETAILED DESCRIPTION
[0036] The specific implementation methods of the present application are further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but are not intended to limit the scope of the present application.
[0037] 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 not necessarily to describe a particular sequence or order.
[0038] The directional words such as up, down, left, right, front, back, top, bottom, etc. (if any) involved in the specification and claims of this application are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional words should not limit the scope of protection requested by this application.
[0039] like Figure 1 As shown, an embodiment of the present application provides a tab pole piece 1, which, before being cut, comprises a coating area 11 and an empty foil area 12 located on one side of the coating area 11, and a boundary line 13 is formed at the position where the empty foil area 12 and the coating area 11 meet. Specifically, the tab pole piece 1 is a rectangular structure before cutting, and the tab pole piece 1 has a length direction X and a width direction Y. In the width direction Y of the tab pole piece 1, the tab pole piece 1 is divided into a coating area 11 and an empty foil area 12. The coating area 11 is coated with an active material, and the empty foil area 12 is not coated with an active material.
[0040] like Figures 2 to 4 As shown, after the pole tab pole piece 1 is cut, the empty foil area 12 is cut to form a plurality of pole tabs 14 of quadrilateral structure, and the plurality of pole tabs 14 are arranged in sequence along the length direction X of the pole tab pole piece 1. The four sides of each pole tab 14 include 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 junction line 13, and the third side 143 is parallel to the junction line 13 and the distance from the junction line 13 is less than 5 mm. The first side 141 and the second side 142 are arranged opposite to each other, and the first side 141 and the second side 142 both intersect with the third side 143. When the distance between the third side 143 and the junction line 13 is 0 mm, the third side 143 coincides with the junction line 13. The angle formed between the first side 141 and the third side 143 is a, and the angle a is an acute angle.
[0041] Specifically, the tab pole piece 1 is a positive tab pole piece 21 and / or a negative tab pole piece 22 (the structures of the positive tab pole piece 21 and the negative tab pole piece 22 can be seen in Figure 5 , Figure 8 and Fig. 9 ), the winding direction S of the pole tab and pole piece 1 is the same as the direction of the angle a. Figure 5 As shown, the winding direction S of the positive electrode tab pole piece 21 and the negative electrode tab pole piece 22 is from Figure 5In the middle, the direction of the angle a of the positive pole tab pole piece 21 and the negative pole tab pole piece 22 during the winding process is the same as the winding direction S. In this embodiment, the pole tab 14 is arranged in a quadrilateral structure, and the angle a formed between the first side 141 and the third side 143 is an acute angle. In the process of winding the pole tab pole piece 1 to form a battery cell, the winding direction S of the pole tab pole piece 1 is consistent with the direction of the acute angle. The pole tab 14 is folded and smoothed toward the hole core while winding the pole tab pole piece 1, which can effectively reduce the roller pressure required when smoothing the pole tab 14, thereby avoiding the deformation of the coating area 11 of the pole tab pole piece 1, and at the same time reducing the shedding of the active material on the pole tab pole piece 1, greatly improving the yield rate of the fully-earthed winding battery cell.
[0042] like Figure 3 As shown, as an embodiment, the four sides of each pole ear 14 also include a fourth side 144, which is away from the boundary line 13 and arranged opposite to the third side 143, and the fourth side 144 and the first side 141, the second side 142 and the third side 143 together form a quadrilateral.
[0043] like Figure 3 As shown, as an implementation manner, the third side 143 coincides with the boundary line 13 , and the fourth side 144 and the third side 143 are parallel to each other.
[0044] Of course, the third side 143 may not coincide with the boundary line 13. Fig.13 As shown in FIG. 1 , as an embodiment, the third side 143 and the boundary line 13 are spaced apart from each other, and the empty foil area 12 between the third side 143 and the boundary line 13 is a parallelogram structure. Fig.14 As shown, as another embodiment, the third side 143 and the boundary line 13 are spaced apart from each other, and the empty foil area 12 between the third side 143 and the boundary line 13 is a rectangular structure.
[0045] like Fig.12 As shown, as an embodiment, the angle formed between the first side 141 and the fourth side 144 is rounded, and the angle formed between the second side 142 and the fourth side 144 is rounded. After the rounding, the intersection of the two sides is a smooth transition, which is more conducive to reducing the pressure required to smooth the tab 14 and reducing tip discharge.
[0046] like Figure 3 As shown, as an implementation mode, the angle formed between the second side 142 and the third side 143 is b, the angle b is a right angle or an obtuse angle, and the sum of the angle a and the angle b is less than or equal to 180°.
[0047] As another implementation, the angle b is an obtuse angle, and the sum of the angle a and the angle b is equal to 180°, that is, in this embodiment, the pole lug 14 is a parallelogram structure.
[0048] like Figure 3 and Figure 4 As shown, as an implementation manner, the angle a formed between the first side 141 and the third side 143 is less than 60°.
[0049] As another implementation, the angle a is greater than or equal to 15° and less than or equal to 45°.
[0050] like Figures 2 to 4 As shown, as an implementation mode, a gap is provided 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 (ie, the length of the third side 143 or the fourth side 144 ).
[0051] As another embodiment, the length N of the interval is 1 / 100 to 1; or 1 / 10 to 1 / 2; or 1 / 5 to 1 / 3 of the length L of the tab 14 .
[0052] As an implementation manner, the length N of the interval is 0.1 mm-10 mm.
[0053] like Figure 4 As shown, as an implementation mode, the ratio of the length L to the width W of each pole ear 14 is (1-4):2.
[0054] As another embodiment, the ratio of the length L to the width W of each pole ear 14 is (1-3):2 or 0.5:1.
[0055] Of course, in other embodiments, the tab 14 may also be in other shapes, such as a trapezoidal structure. Fig.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, that is, the pole lug 14 is a right-angled trapezoidal structure. At the same time, from left to right, in every two adjacent pole lugs 14, the second side 142 of the previous pole lug 14 at one end close to the junction line 13 is connected to the first side 141 of the next pole lug 14 at one end close to the junction line 13 (that is, there is no gap between the two), and because the pole lug 14 is a trapezoidal structure, the second side 142 of the previous pole lug 14 at one end away from the junction line 13 and the first side 141 of the next pole lug 14 at one end away from the junction line 13 are spaced from each other, and the length N of the interval is 1 / 10 to 1 / 2 of the length of the third side 143.
[0056] like Fig.11As shown, in another embodiment, the angle formed between the first side 141 and the third side 143 is an acute angle, the angle formed 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 pole lug 14 is an obtuse trapezoidal structure. At the same time, from left to right, in every two adjacent pole lugs 14, the second side 142 of the previous pole lug 14 at one end close to the junction line 13 is connected to the first side 141 of the next pole lug 14 at one end close to the junction line 13 (that is, there is no gap between the two), and because the pole lug 14 is a trapezoidal structure, the second side 142 of the previous pole lug 14 at one end away from the junction line 13 and the first side 141 of the next pole lug 14 at one end away from the junction line 13 are spaced from each other, and the length N of the interval is 1 / 10 to 1 / 2 of the length of the third side 143.
[0057] like Figures 5 to 9 As shown, this embodiment further provides a wound battery, including a positive pole tab pole piece 21 and a negative pole tab pole piece 22 , and both the positive pole tab pole piece 21 and the negative pole tab pole piece 22 are the pole tab pole piece 1 described above.
[0058] like Figure 5 As shown, as an embodiment, the wound battery further includes a first separator 23, which is sandwiched between the positive pole tab sheet 21 and the negative pole tab sheet 22. The positive pole tab sheet 21, the first separator 23 and the negative pole tab sheet 22 are stacked and wound to form a battery cell 2, and the tabs 211 on the positive pole tab sheet 21 and the tabs 221 on the negative pole tab sheet 22 are respectively located at the two ends of the battery cell 2. Figure 6 and Figure 7 As shown, after the winding is completed and the tabs 211 / 221 are flattened, the tabs 211 on the positive tab pole piece 21 and the tabs 221 on the negative tab pole piece 22 are respectively overlapped to form a ring shape.
[0059] Specifically, Figure 5 , Figure 8 and Fig. 9 As shown, the direction of the angle a on the tab 211 of the positive tab pole piece 21 and the direction of the angle a on the tab 221 of the negative tab pole piece 22 are the same as the winding direction S. During the winding process of the battery cell 2, by winding the positive and negative tab pole pieces 21 / 22 while smoothing the tabs 211 / 221 toward the hole core 20, the roller pressure required for smoothing the tabs 211 / 221 can be effectively reduced, thereby avoiding the deformation of the positive and negative tab pole pieces 21 / 22, and reducing the shedding of active materials on the positive and negative tab pole pieces 21 / 22, thereby greatly improving the yield rate of the fully tab wound battery cell.
[0060] As an implementation method, Figure 8 and Fig. 9As shown, the tab 211 of the positive tab pole piece 21 and the tab 221 of the negative tab pole piece 22 are both rounded, and the intersection of the two sides after the rounding is a smooth transition, which is more conducive to reducing the pressure required to smooth the tabs 211 / 221; and reducing tip discharge.
[0061] As an embodiment, the wound battery further includes a second separator 24 , and the positive electrode tab pole piece 21 , the first separator 23 , the negative electrode tab pole piece 22 and the second separator 24 are stacked in sequence from the inside to the outside, and the four are stacked and wound to form a battery cell 2 .
[0062] As an embodiment, the tab 211 on the positive pole tab piece 21 extends beyond the top of the first diaphragm 23 by 0.5-5 mm after being smoothed, and the tab 221 on the negative pole tab piece 22 extends beyond the bottom of the first diaphragm 23 by less than 5 mm after being smoothed.
[0063] As another embodiment, the tab 211 on the positive pole tab piece 21 extends beyond the top of the first diaphragm 23 by less than 3 mm after being smoothed, and the tab 221 on the negative pole tab piece 22 extends beyond the bottom of the first diaphragm 23 by less than 3 mm after being smoothed.
[0064] As another embodiment, the distance that the tab 211 on the positive pole tab pole piece 21 protrudes from the top end of the first diaphragm 23 after being smoothed is less than 3 mm and greater than 1.5 mm; the distance that the tab 221 on the negative pole tab pole piece 22 protrudes from the bottom end of the first diaphragm 23 after being smoothed is less than 3 mm and greater than 1.5 mm.
[0065] The present embodiment also provides a method for preparing a wound battery, which specifically includes: conventionally coating the positive pole tab pole piece 21 and the negative pole tab pole piece 22 with a coating machine to ensure that empty foil areas are formed on the positive pole tab pole piece 21 and the negative pole tab pole piece 22; forming a plurality of quadrilateral pole tabs 211 and / or 221 by laser cutting the empty foil areas of the positive pole tab pole piece 21 and / or the negative pole tab pole piece 22; and then winding the positive pole tab pole piece 21, the negative pole tab pole piece 22 and the separator 23 / 24 into a columnar shape, and during the winding process, the pole tabs 211 / 221 are folded and smoothed toward the hole core 20.
[0066] The pole tab pole piece 1 provided in the embodiment of the present application has a pole tab 14 arranged in a quadrilateral structure, and the angle a formed between the first side 141 and the third side 143 is an acute angle. In the process of winding the pole tab pole piece 1 to form a battery cell, the winding direction S of the pole tab pole piece 1 is consistent with the direction of the acute angle. By winding the pole tab pole piece 1 while smoothing the pole tab 14 toward the hole core 20, the roller pressure required when smoothing the pole tab 14 can be effectively reduced, thereby avoiding the deformation of the pole tab pole piece 1, and at the same time reducing the shedding of active materials on the pole tab pole piece 1, greatly improving the yield rate of the fully pole tab wound battery cell. In addition, since a lot of pressure is not required when smoothing the pole tab 14, the stress of the bent pole tab 14 can be reduced, thereby ensuring the quality of the wound battery. The wound battery not only has a simple design, but also has good electrical performance, high yield, and strong practicality.
[0067] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.
Claims
1. A tab pole piece, comprising a coating area (11) and a hollow foil area (12) located on one side of the coating area (11), wherein the hollow foil area (12) and the coating area (11) meet to form a boundary line (13), characterized in that: The hollow foil area (12) is cut to form a plurality of pole ears (14) of a quadrilateral structure, the plurality of pole ears (14) being arranged in sequence along the length direction (X) of the pole ear pole piece (1), the four sides of each pole ear (14) comprising a first side (141), a second side (142) and a third side (143), the third side (143) being located in the hollow foil area (12) and close to the boundary line (13), the third side (143) being parallel to the boundary line (13) and the distance from the boundary line (13) being less than 5 mm; the first side (141) and the second side (142) being arranged opposite to each other, and the first side (141) and the second side (142) both intersecting with the third side (143), the angle formed between the first side (141) and the third side (143) being a, and the angle a being an acute angle; The four sides of each of the pole ears (14) further include a fourth side (144), the fourth side (144) being away from the boundary line (13) and arranged opposite to the third side (143), the fourth side (144) and the first side (141), the second side (142) and the third side (143) together forming a quadrilateral; the angle formed between the first side (141) and the fourth side (144) is rounded, and / or the angle formed between the second side (142) and the fourth side (144) is rounded.
2. The tab pole piece according to claim 1, characterized in that: The pole tab pole piece (1) is a positive pole tab pole piece (21) and / or a negative pole tab pole piece (22), and the winding direction (S) of the pole tab pole piece (1) is the same as the direction of the angle a.
3. The tab pole piece according to claim 1, characterized in that: The angle formed between the second side (142) and the third side (143) is b, the angle b is a right angle or an obtuse angle, and the sum of the angle a and the angle b is less than or equal to 180°.
4. The pole piece of the pole tab according to claim 1, characterized in that: The pole lug (14) is a parallelogram structure.
5. The pole tab and pole piece according to any one of claims 1 to 4, characterized in that: A gap is provided between every two adjacent pole lugs (14), and the length (N) of the gap is 1 / 10 to 1 / 2 of the length (L) of the pole lug (14).
6. The pole piece of the pole tab according to claim 5, characterized in that: The length (N) of the interval is 0.1 mm-10 mm.
7. The pole tab and pole piece according to any one of claims 1 to 4, characterized in that: The ratio of the length (L) to the width (W) of each pole lug (14) is (1-4):
2.
8. A wound battery, comprising a positive electrode tab (21) and a negative electrode tab (22), characterized in that: The positive electrode tab pole piece (21) and / or the negative electrode tab pole piece (22) is the tab pole piece (1) according to any one of claims 1 to 7.
9. The wound battery according to claim 8, characterized in that The wound battery further comprises a first diaphragm (23), wherein the first diaphragm (23) is sandwiched between the positive pole tab pole sheet (21) and the negative pole tab pole sheet (22); the positive pole tab pole sheet (21), the first diaphragm (23) and the negative pole tab pole sheet (22) are stacked and wound to form a battery cell (2); the pole tab (211) on the positive pole tab pole sheet (21) and the pole tab (221) on the negative pole tab pole sheet (22) are respectively located at two ends of the battery cell (2).
10. The wound battery according to claim 9, characterized in that The distance that the pole ear (211) on the positive pole ear pole piece (21) protrudes from the top end of the first diaphragm (23) after being smoothed is 0.5-5 mm, and the distance that the pole ear (221) on the negative pole ear pole piece (22) protrudes from the bottom end of the first diaphragm (23) after being smoothed is less than 5 mm.