CN218299826U

CN218299826U - Pole piece, roll up core and battery

Info

Publication number: CN218299826U
Application number: CN202222765137.9U
Authority: CN
Inventors: 余正发; 彭冲
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2022-10-17
Filing date: 2022-10-17
Publication date: 2023-01-13
Anticipated expiration: 2032-10-17

Abstract

The embodiment of the application provides a pole piece, roll up core and battery, wherein, this pole piece has dodges district and at least one empty foil district, at least one empty foil district includes first empty foil district, follows the length direction of pole piece, first empty foil district with dodge the district and stagger the setting, dodge the district and extend to the first edge of pole piece, first empty foil district is used for connecting the utmost point ear of pole piece, dodge the district be used for dodge with the utmost point ear of the pole piece relative of pole piece. Through set up on the pole piece and dodge the district, be the coiling structure at electric core, under the condition that the cream was scribbled to remaining in another pole piece utmost point ear place edge, can provide the holding position for another pole piece utmost point ear to improve the lithium ion battery's that forms roughness, and then improve lithium ion battery's energy density.

Description

Pole piece, roll core and battery

Technical Field

The application relates to the technical field of batteries, in particular to a pole piece, a roll core and a battery.

Background

In order to reduce the internal resistance of the lithium ion battery, the tab is usually disposed in the middle of the electrode plate, i.e., the tab is disposed in the middle. However, in the production process of the lithium ion battery with the tab middle-arranged structure, the coating paste in the partial area of the pole piece needs to be removed for welding the tab. However, after slitting into battery pole pieces, the edges of the pole pieces typically remain pasted to a certain size. When welding utmost point ear on the pole piece, utmost point ear can overlap with the scribbling cream of retaining, and in winding structure, can lead to the thickness of this position to be thicker than other positions of pole piece for lithium ion battery's roughness is low, and then influences lithium ion battery's energy density.

SUMMERY OF THE UTILITY MODEL

The embodiment of the application provides a pole piece, a winding core and a battery, and aims to solve the problem that the flatness of a lithium ion battery is low in a winding structure due to the fact that coating paste is reserved on the edge of the pole piece, and further the energy density of the lithium ion battery is influenced.

In order to solve the technical problem, the present application is implemented as follows:

in a first aspect, the embodiment of the present application provides a pole piece, the pole piece has dodges district and at least one empty foil district, at least one empty foil district includes first empty foil district, follows the length direction of pole piece, first empty foil district with dodge the district and stagger the setting, dodge the district and extend to the first edge of pole piece, first empty foil district is used for connecting the utmost point ear of pole piece, dodge the district be used for dodge with the utmost point ear of another pole piece that the pole piece is relative.

Optionally, a groove is formed in the pole piece, the groove extends to the first edge, and the notch forms the avoiding area.

Optionally, the avoiding region is located on the first surface of the pole piece;

the active material layer is arranged in the area of the first surface except the empty foil area and the avoiding area, or the active material layer is arranged in the area of the first surface except the empty foil area, and the thickness of the active material layer in the avoiding area is smaller than that of the active material layer in the area except the empty foil area.

Optionally, the first empty foil region comprises a first sub empty foil region located at a first surface of the pole piece and a second sub empty foil region located at a second surface of the pole piece;

the first sub empty foil area and the second sub empty foil area are overlapped in the vertical projection area of the pole piece.

Optionally, the avoidance region includes a first sub avoidance region located on the first surface of the pole piece and a second sub avoidance region located on the second surface of the pole piece;

the first sub-avoidance area and the second sub-avoidance area are overlapped in the vertical projection area of the pole piece.

Optionally, neither the first empty foil region nor the avoiding region is located at an end of the current collector, and the at least one empty foil region further includes a second empty foil region located at an end of the first surface of the pole piece and a third empty foil region located at an end of the second surface of the pole piece.

Optionally, in a length direction of the pole piece, a size of the second empty foil area is larger than a size of the third empty foil area.

In a second aspect, an embodiment of the present application provides a winding core, including a positive plate, a diaphragm, and a negative plate, where the negative plate, the diaphragm, and the positive plate are sequentially stacked and wound to form the winding core;

at least one of the positive electrode tab and the negative electrode tab adopts the structure of the tab according to the first aspect.

Optionally, at least one of the negative electrode plates is in the structure of the electrode plate according to the first aspect, and the positive electrode plate tab is located in the avoiding region.

In a third aspect, the present application provides a battery, including the winding core according to the third aspect.

In the embodiment of the application, this pole piece has dodges district and at least one empty foil district, at least one empty foil district includes first empty foil district, follows the length direction of pole piece, first empty foil district with dodge the district and stagger the setting, dodge the district and extend to the first edge of pole piece, first empty foil district is used for connecting the pole piece utmost point ear, dodge the district be used for dodge with the utmost point ear of another pole piece that the pole piece is relative. Through set up on the pole piece and dodge the district, be the coiling structure at electric core, with this pole piece relative another pole piece utmost point ear place the edge and leave the condition of scribbling the cream, can provide the holding position for another pole piece utmost point ear to improve the lithium ion battery's that forms roughness, and then improve lithium ion battery's energy density.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural view of a negative electrode sheet in the related art;

fig. 2 is a first schematic structural diagram of a pole piece provided in an embodiment of the present application;

fig. 3 is a schematic structural diagram of a pole piece according to an embodiment of the present application;

fig. 4 is a first schematic structural diagram of a negative electrode sheet provided in an embodiment of the present application;

fig. 5 is a second schematic structural diagram of a negative electrode sheet provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram three of a negative electrode sheet provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a negative electrode sheet provided in an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a winding core provided in an embodiment of the present application;

FIG. 9 is a first cross-sectional view of FIG. 8;

fig. 10 is a second cross-sectional view of fig. 8.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like, as used herein do not denote any order, quantity, or importance. But merely serve to distinguish between different components. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships are changed accordingly.

At present, battery tab usually has two kinds of mode of setting up, and first kind, battery tab set up in pole piece head position, and under this kind of condition, the battery has the big problem of internal resistance to can't satisfy lithium ion battery quick charge's performance requirement. And secondly, the lug is arranged in the middle of the lithium ion battery pole piece, namely, the lug middle structure is equivalent to divide the battery pole piece into two parts, and the pole pieces on the two sides of the lug are connected in parallel, so that the internal resistance of the lithium ion battery can be obviously reduced.

However, in the production process of the ionic battery with the tab-in-place structure, the pasting of partial areas of the pole pieces needs to be removed for welding the tabs. However, after slitting into battery pole pieces, a certain amount of pasting paste is typically left at the edges of the pole pieces. When welding utmost point ear on the pole piece, utmost point ear can overlap with the scribble cream of reserving, as shown in figure 1, in winding structure, can lead to the thickness of this position to be thicker than other positions of pole piece for lithium ion battery's roughness is low, and then influences lithium ion battery's energy density.

In order to solve the above technical problem, embodiments of the present application provide a pole piece, a winding core and a battery, and the present application is specifically described in detail by the following embodiments.

Referring to fig. 2, fig. 2 is a first schematic structural diagram of a pole piece according to an embodiment of the present disclosure. Pole piece 100 has and dodges district 10 and at least one empty foil district, at least one empty foil district includes first empty foil district 20, and follows pole piece 100's length direction, first empty foil district 20 with dodge district 10 and stagger the setting, dodge district 10 and extend to pole piece 100's first edge, first empty foil district 20 is used for connecting the pole piece utmost point ear, dodge district 10 be used for dodging with the utmost point ear of the pole piece relative of pole piece.

It should be understood that the embodiments of the present application may be used for a negative electrode tab or a positive electrode tab of a lithium ion battery. Specifically, under the condition that the pole piece that this application embodiment provided is the negative pole piece, through set up on the pole piece 100 of negative pole piece dodge district 10, dodge district 10 and extend to the first edge of pole piece 100, the edge at negative pole piece utmost point ear place promptly is at electric core for coiling structure, and under the condition of scribbling the cream was left in positive pole piece utmost point ear place edge, for positive pole piece utmost point ear provides dodge the position to improve lithium ion battery's roughness, and then improve lithium ion battery's energy density. And under the condition that the pole piece that this application embodiment provided is the positive plate, through set up on the positive plate and dodge district 10, dodge district 10 and extend to the first edge of pole piece 100, the edge at positive plate utmost point ear place promptly, be the coiling structure at electric core, and under negative plate utmost point ear place edge left the condition of scribbling the cream, for negative plate utmost point ear provide dodge position to improve lithium ion battery's roughness, and then improve lithium ion battery's energy density.

It should be understood that the tab on the pole piece 100 is a center-located structure, and the first empty foil area 20 may be a tab slot located on the pole piece 100, and the tab of the pole piece 100 is electrically connected to the pole piece 100 in the first empty foil area 20.

It should be understood that the end of the pole piece 100 may be a winding start end, and since the positive tab and the negative tab of the battery cell are located at two sides of the winding structure of the battery cell, the first empty foil area on the pole piece 100 needs to be offset from the avoidance area 10 providing an avoidance position for the other pole tab, and the avoidance area 10 may be located between the first empty foil area 20 and the end of the pole piece 100, or located at a side of the first empty foil area 20 away from the end of the pole piece 100, which is not limited in this embodiment.

In the embodiment of the present application, this pole piece 100 has dodges district 10 and at least one empty foil district, at least one empty foil district includes first empty foil district 20, first empty foil district 20 with dodge district 10 and all not be located the tip of pole piece 100, and follow the length direction of pole piece 100, first empty foil district 20 with dodge district 10 and stagger the setting, dodge district 10 and extend to pole piece 100's first edge, first empty foil district 20 is used for connecting pole piece 100's utmost point ear, dodge district 10 be used for dodge with pole piece 100 another pole piece's relative utmost point ear. Through set up on pole piece 100 and dodge district 10, be the winding structure at electric core, with the pole ear place edge of another pole piece relative with this pole piece 100 leave the condition of scribbling the cream, can provide the holding position for it to improve the lithium ion battery's that forms roughness, and then improve lithium ion battery's energy density.

In an alternative embodiment, as shown in fig. 3, the pole piece 100 is provided with a groove extending to the first edge, and the groove forms the relief area 10.

In this embodiment, through set up the recess on pole piece 100, the recess extends to first edge, and the edge at utmost point ear place promptly is for coiling structure at electric core, and leaves the condition of scribbling the cream with the relative pole piece utmost point ear place edge of this pole piece 100 under, dodges the position for it provides to improve lithium ion battery's roughness, and then improve lithium ion battery's energy density.

In an alternative embodiment, the avoiding region 10 is located on the first surface 110 of the pole piece 100;

active material layers are arranged on the first surface 110 except for the empty foil area and the avoiding area 10, or the active material layers are arranged on the first surface 110 except for the empty foil area, and the thickness of the active material layers in the avoiding area 10 is smaller than that of the active material layers in the area except for the empty foil area.

It is to be understood that the void foil areas may include void foil areas for attachment of pole piece tabs and may also include void foil areas disposed at the ends of the pole piece 100.

In an alternative embodiment, the avoiding region 10 is located on the first surface 110 of the pole piece 100, and the first surface 110 is provided with an active material layer in the region except the empty foil region and the avoiding region 10. Because the avoiding region 10 is not provided with an active material layer, under the condition that the battery cell is of a winding structure and the pasting paste is left at the edge of the other pole piece tab opposite to the pole piece 100, an avoiding position is provided for the battery cell, so that the flatness of the lithium ion battery is improved, and the energy density of the lithium ion battery is further improved.

In an optional embodiment, the avoiding region 10 is located on the first surface 110 of the pole piece 100, the first surface 110 is provided with an active material layer in a region except the above-mentioned empty foil region, and the thickness of the active material layer provided in the avoiding region 10 is smaller than the thickness of the active material layer in the region except the empty foil region, and when the battery cell is in a winding structure and the edge of the other pole piece tab opposite to the pole piece 100 is left with the paste, an avoiding position can be provided for the battery cell, so that the flatness of the lithium ion battery is improved, and the energy density of the lithium ion battery is further improved.

It should be noted that, the avoidance area 10 is not provided with an active material layer, and an avoidance space provided for another pole piece tab opposite to the pole piece 100 is larger than an avoidance space provided for another pole piece tab when the thickness of the active material layer in the avoidance area 10 is reduced.

Optionally, as shown in fig. 4 to 7, neither the first empty foil area 20 nor the relief area 10 is located at an end of the pole piece, and the first empty foil area 20 includes a first sub-empty foil area 21 located at the first surface 110 of the pole piece 100 and a second sub-empty foil area 22 located at the second surface 120 of the pole piece 100;

the first sub-empty foil area 21 and the second sub-empty foil area 22 coincide in the vertical projection area of the pole piece 100.

It should be understood that the pole piece 100 includes two tabs oppositely disposed on the first surface 110 and the second surface 120 of the pole piece 100, wherein one tab is electrically connected to the pole piece 100 through the first sub-empty foil area 21 on the first surface 110, and the other tab is electrically connected to the pole piece 100 through the second sub-empty foil area 22 on the second surface 120.

Optionally, the avoidance region 10 includes a first sub avoidance region 11 located on the first surface 110 of the pole piece 100 and a second sub avoidance region 12 located on the second surface 120 of the pole piece 100;

the first sub-avoidance area 11 and the second sub-avoidance area 12 are overlapped in the vertical projection area of the pole piece 100.

In this embodiment, a first sub-avoidance region 11 is disposed on the first surface 110 of the pole piece 100, a second sub-avoidance region 12 is disposed on the second surface 120 of the pole piece 100, and the first sub-avoidance region 11 and the second sub-avoidance region 12 are overlapped in a vertical projection area of the pole piece 100. Under the condition that the battery cell is of a winding structure and the coating paste is reserved at the edge of the other pole piece lug opposite to the pole piece 100, an avoiding space can be provided for the battery cell, compared with the situation that the avoiding area 10 is arranged on one surface of the pole piece 100, the total avoiding space arranged on the surface of the pole piece 100 can be improved, so that the flatness of the lithium ion battery is improved, and the energy density of the lithium ion battery is further improved.

In a specific implementation, as shown in fig. 4, the first sub avoidance region 11 and the second sub avoidance region 12 may not be provided with an active material layer, and at this time, the total avoidance space formed by the first sub avoidance region 11 and the second sub avoidance region 12 is the largest.

In another alternative embodiment, as shown in fig. 5 and 6, the first sub-avoidance region 11 is not provided with an active material layer, and the second sub-avoidance region 12 is provided with an active material layer having a thickness smaller than that of the active material layer except for the empty foil region, or the first sub-avoidance region 11 is provided with an active material layer having a thickness smaller than that of the active material layer except for the empty foil region, and the second sub-avoidance region 12 is not provided with an active material layer, in this case, a total avoidance space formed by the first sub-avoidance region 11 and the second sub-avoidance region 12 is smaller than a maximum avoidance space, and specifically, the size of the total avoidance space is related to the thickness of the active material layer provided in the first sub-avoidance region 11 or the second sub-avoidance region 12, which is not limited in this embodiment.

In another alternative embodiment, as shown in fig. 7, the first sub-avoidance region 11 and the second sub-avoidance region 12 are both provided with an active material layer having a thickness smaller than that of the active material layer in the region outside the empty foil region, at this time, the total avoidance space formed by the first sub-avoidance region 11 and the second sub-avoidance region 12 is the smallest, specifically, the size of the total avoidance space is related to the thickness of the active material layer provided in the first sub-avoidance region 11 and the second sub-avoidance region 12, which is not limited in this embodiment.

Optionally, the at least one empty foil region further comprises a second empty foil region 30 at an end of the first surface 110 and a third empty foil region 40 at an end of the second surface 120 of the pole piece 100.

Optionally, in the length direction of the pole piece 100, the size of the second empty foil area 30 is larger than the size of the third empty foil area 40.

Referring to fig. 8 to 10, the present application further provides a winding core 200, which includes a positive electrode sheet 210, a separator 220, and a negative electrode sheet 230, wherein the negative electrode sheet 230, the separator 220, and the positive electrode sheet 210 are sequentially stacked and wound to form the winding core;

at least one of the positive electrode tab 210 and the negative electrode tab 230 has the above-described tab structure.

During concrete implementation, under the condition that the pole piece that this application embodiment provided is negative pole piece 230, through set up on negative pole piece 230 and dodge the district, dodge the first edge that the district extends to the pole piece, the edge at negative pole piece 230 utmost point ear place promptly, be winding structure at electric core, and under the condition that positive pole piece 210 utmost point ear place edge left and scribbled the cream, for positive pole piece 210 utmost point ear provides dodge the position to improve lithium ion battery's roughness, and then improve lithium ion battery's energy density. And under the condition that the pole piece that this application embodiment provided is positive plate 210, through set up on positive plate 210 and dodge the district, dodge the first edge that the district extends to the pole piece, the edge at positive plate 210 utmost point ear place promptly, be the coiling structure at electric core, and under the condition that scribble the cream was left in the edge at negative plate 230 utmost point ear place, for the position is dodged to negative plate 230 utmost point ear provides to improve lithium ion battery's roughness, and then improve lithium ion battery's energy density.

Since the technical solution of this embodiment includes all technical solutions of the above embodiments, at least all technical effects of the above embodiments can be achieved, and details are not repeated here.

Optionally, at least one of the negative electrode sheets 230 adopts the structure of the electrode sheet described above, and the positive electrode sheet 210 is located in the avoidance area.

It should be understood that the present embodiment is applicable to the negative electrode sheet 230 of the lithium ion battery, wherein the conductive electrode sheet of the negative electrode sheet 230 is typically made of an electrolytic copper foil with a thickness of 7-15um, and the conductive electrode sheet of the positive electrode sheet 210 is typically made of an electrolytic aluminum foil with a thickness of 10-20 um. On the other hand, since the thickness of the negative electrode sheet 230 is smaller than that of the positive electrode sheet 210, the negative electrode sheet 230 is more flexible than the positive electrode sheet 210. The avoidance area is arranged on the pole piece of the negative pole piece 230, the avoidance area extends to the first edge of the pole piece, namely the edge where the pole lug of the negative pole piece 230 is located, the electric core is of a winding structure, and the edge where the pole lug of the positive pole piece 210 is located is provided with the avoidance position for the pole lug of the positive pole piece 210, so that the flatness of the lithium ion battery is improved, and the energy density of the lithium ion battery is further improved.

It should be understood that the tab on the negative electrode sheet 230 is a central structure, the first empty foil region may be a tab slot located on the negative electrode sheet 230, and the tab of the negative electrode sheet 230 is electrically connected to the tab in the first empty foil region.

It should be understood that, an end portion of a pole piece of the negative pole piece 230 may be a winding start end of the negative pole piece 230, and since the positive pole tab and the negative pole tab of the battery cell are located at two opposite sides of the winding structure of the battery cell, the first empty foil region on the negative pole piece 230 needs to be disposed in a staggered manner with an avoidance region that provides an avoidance position for the pole tab of the positive pole piece 210, and the avoidance region may be located between the first empty foil region and the end portion of the pole piece, or located at one side of the first empty foil region 20 away from the end portion of the pole piece, which is not limited in this embodiment.

The application also provides a battery, including above-mentioned book core. Since the technical solution of this embodiment includes all technical solutions of the above embodiments, at least all technical effects of the above embodiments can be achieved, and details are not repeated here.

In addition, in order to better understand the embodiments of the present application, the following embodiments are used to describe the electrode sheet, the winding core and the battery in detail, wherein the electrode sheet provided in the present application is taken as an example of the negative electrode sheet.

Fig. 1 is a pole piece schematic diagram after welding a pole lug of a lithium ion battery positive plate with a pole lug middle-arranged structure, the lithium ion battery is formed by the positive plate in fig. 1 and a negative plate without the thickness of an active material for containing the position of the positive plate, and because the edge of a positive plate lug groove has a positive active material layer, the positive active material layer is overlapped with the pole lug, the flatness of the lithium ion battery can be reduced, the thickness of the battery is increased, and the energy density of the lithium ion battery is influenced. In addition, the flatness of the battery is poor, and a lithium ion transmission channel in a local area is blocked, so that the cycle performance of the lithium ion battery is deteriorated, and the cycle life of the lithium ion battery is influenced.

As shown in fig. 2, 100 is a negative plate, 20 is a first groove of the negative plate, which is used for a negative tab on the negative plate of a welding machine, and 10 is a second groove of the negative plate, which is used for accommodating the thickness of the paste layer at the edge of the groove of the positive tab of the positive plate. The length of the second groove is L, the width of the second groove is W, the paste coating thickness of the second groove is H, the paste coating thickness of the pole piece at the position other than the second groove is H, and the paste coating width of the edge of the positive pole piece is L; the length of the positive tab is X, the width of the positive tab is Y, and the thickness of the positive tab is Z. The relationship among the size of the second groove, the paste coating thickness of the positive plate and the size of the tab is as follows: H/H is more than or equal to 0 and less than 1; L/L is more than or equal to 1; W/Y is more than or equal to 1.

Fig. 10 is a schematic structural diagram of a winding core formed by the negative electrode plate according to the embodiment of the present application, and the second groove on the negative electrode plate can effectively accommodate the edge paste thickness of the positive electrode plate, so that the flatness of the lithium ion battery can be improved, the energy density of the lithium ion battery can be improved, and the improvement of the cycle life of the lithium ion battery can be facilitated. Because the positive tab and the positive plate edge paste coating overlap, the negative plate has a second groove for accommodating the difference of the battery thickness flatness caused by the overlap of the positive tab and the positive plate edge paste coating, and the flatness of the lithium ion battery can be improved.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The utility model provides a pole piece, its characterized in that, the pole piece has dodges district and at least one empty foil district, at least one empty foil district includes first empty foil district, follows the length direction of pole piece, first empty foil district with dodge the district setting of staggering, dodge the district and extend to the first edge of pole piece, first empty foil district is used for connecting the utmost point ear of pole piece, dodge the district be used for dodge with the utmost point ear of another pole piece that the pole piece is relative.

2. The pole piece of claim 1 wherein a groove is disposed in the pole piece, the groove extending to the first edge, the groove forming the relief area.

3. The pole piece of claim 1 wherein said relief area is located on a first surface of said pole piece;

4. The pole piece of claim 1, wherein the first empty foil region comprises a first sub-empty foil region at a first surface of the pole piece and a second sub-empty foil region at a second surface of the pole piece;

5. The pole piece of claim 1 wherein said relief area comprises a first sub-relief area on a first surface of said pole piece and a second sub-relief area on a second surface of said pole piece;

6. The pole piece of claim 1 wherein neither the first void foil zone nor the relief zone is located at an end of the pole piece, the at least one void foil zone further comprising a second void foil zone located at an end of the first surface of the pole piece and a third void foil zone located at an end of the second surface.

7. The pole piece of claim 6 wherein the second void foil area has a dimension that is greater than a dimension of the third void foil area in a lengthwise direction of the pole piece.

8. The winding core is characterized by comprising a positive plate, a diaphragm and a negative plate, wherein the negative plate, the diaphragm and the positive plate are sequentially stacked and wound to form the winding core;

at least one of the positive electrode tab and the negative electrode tab adopts the structure of the tab according to any one of claims 1 to 7.

9. The winding core according to claim 8, characterized in that the negative pole piece adopts the structure of the pole piece according to any one of claims 1 to 7, and the positive pole piece tab is positioned in the avoidance area.

10. A battery comprising a jellyroll according to claim 8 or 9.