CN218160451U

CN218160451U - Pole piece and battery

Info

Publication number: CN218160451U
Application number: CN202222402801.3U
Authority: CN
Inventors: 袁文兵; 阳成海; 何伊; 谢继春
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2022-12-27
Anticipated expiration: 2032-09-09

Abstract

The utility model provides a pole piece and a battery, wherein the pole piece comprises a first pole piece body and a first connecting piece positioned on one side of the first pole piece body in the length direction, and the first connecting piece is convexly arranged on the first pole piece body; the first pole piece body is provided with a first notch and a second notch which are arranged along the width direction of the first pole piece body, the first notch and the second notch are both positioned on one side edge of the length direction of the first pole piece body, and the two second notches are respectively positioned on two opposite sides of the first connecting piece along the width direction of the first pole piece body. The utility model provides a current pole piece utilization ratio low, influence the lower problem of energy density of battery.

Description

Pole piece and battery

Technical Field

The utility model relates to a battery technology field particularly, relates to a pole piece and battery.

Background

Lithium batteries have high energy density, high voltage system, long cycle, and the like, and thus have been widely used in consumer electronics products such as mobile phones and notebooks, and in systems such as electric vehicles and electric tools.

The lithium ion battery is formed by winding or superposing basic unit structures, wherein the basic unit structures comprise a positive plate, a diaphragm and a negative plate, then a positive lug is welded on the positive plate, a negative lug is welded on the negative plate, and then the lithium ion battery is obtained after the working procedures of entering a shell, packaging, baking, injecting liquid, standing, forming, grading and the like are carried out. The positive tab and the negative tab are current leading-out components of the lithium ion battery, are mainly responsible for inputting and outputting current in the charging and discharging process of the lithium battery cell, and lead out the positive and negative electrodes in the cell through the positive tab and the negative tab.

However, through the fashioned battery of lamination, an external utmost point ear of usually need weld again, the seal of welding external utmost point ear can stretch out battery body, leads to the unnecessary space of current battery too big, influences the utilization ratio of pole piece, is unfavorable for promoting the energy density of battery.

SUMMERY OF THE UTILITY MODEL

The utility model discloses aim at solving current pole piece low-usage, influence the lower problem of energy density of battery.

In order to solve the above problems, a first aspect of the present invention provides a pole piece, including a first pole piece body and a first connection piece located on one side of the first pole piece body in the length direction, wherein the first connection piece is convexly disposed on the first pole piece body;

the first pole piece body is provided with a first notch and a second notch which are arranged along the width direction of the first pole piece body, the first notch and the second notch are both positioned on one side edge of the length direction of the first pole piece body, and the second notches are respectively positioned on two opposite sides of the first connecting piece along the width direction of the first pole piece body.

Further, the dimension of the first notch in the width direction is larger than the dimension of the first connecting piece in the width direction, and/or the dimension of the first notch in the width direction is larger than the dimension of the second notch in the width direction.

Further, the size of the first notch along the width direction is larger than or equal to 4mm and smaller than or equal to

The size of the first gap along the length direction is more than or equal to 70mm, and/or the size of the first gap along the length direction is more than or equal to 3mm and less than or equal to 30mm, and/or the size of the second gap along the width direction is more than or equal to 0.1mm and less than or equal to 10mm.

Further, the shape of the first notch is one or a combination of several of a rectangle, a trapezoid, a U-shaped notch, a V-shaped notch and a semicircle, and/or the shape of the second notch is one or a combination of several of a rectangle, a trapezoid, a U-shaped notch, a V-shaped notch and a semicircle.

The utility model discloses the second aspect provides a battery, including first electric core, first electric core is including folding at least one first positive plate and at least one first negative pole piece of establishing each other, every adjacent first positive plate with be provided with first diaphragm, at least one between the first negative pole piece first positive plate and at least one first negative pole piece is the arbitrary item of first aspect the pole piece.

Furthermore, a third notch and a fourth notch are arranged on the first diaphragm, and the third notch and the fourth notch are arranged along the width direction of the first diaphragm.

Further, the first positive plate and the first negative plate are alternately arranged in a staggered manner, the first connecting piece of the first positive plate, the third notch and the first notch of the first negative plate are arranged in a one-to-one correspondence manner, and the first notch of the first positive plate, the fourth notch and the first connecting piece of the first negative plate are arranged in a one-to-one correspondence manner.

Further, still include the second electric core, first electric core with the second electric core is overlapped each other and is established formation the electric core of battery, the second electric core includes that it establishes and polarity opposite two at least second pole pieces to overlap each other, is provided with the second diaphragm between every two adjacent second pole pieces, the second pole piece includes second pole piece body and second connection piece, the second connection piece is located one side of the length direction of second pole piece body, just the protruding second pole piece body that locates of second connection piece.

Furthermore, the electrode assembly further comprises two electrode lugs with opposite polarities, the two first connecting sheets, the two second connecting sheets and the two electrode lugs are arranged in one-to-one correspondence with the two first notches, and each first connecting sheet, each second connecting sheet and each electrode lug are connected and bent and then contained in one first notch.

Further, the size of the first notch in the width direction is larger than the size of the tab in the width direction, and/or the size of the first notch in the width direction is larger than the size of the second connecting piece in the width direction.

Further, the thickness of the first battery cell is greater than or equal to the sum of the thicknesses of the tab, the first connecting sheet and the second connecting sheet.

Further, an adhesive paper layer is arranged on the surface of one side, away from the second battery cell, of the first battery cell, and the adhesive paper layer covers the surface of the first notch.

Pole piece and battery, including first pole piece body and first connection piece, can make pole piece and utmost point ear connection through first connection piece, first breach and second breach have been seted up along width direction to first pole piece body, a plurality of pole pieces are in turn and the dislocation is overlapped the back, form electric core with first connection piece and utmost point ear connection, be convenient for buckle first connection piece and utmost point ear through the second breach, and first connection piece and utmost point ear buckle the back holding in first breach, the occupation space of utmost point ear at the length direction of electric core has been reduced, electric core length direction's utilization ratio has been increased, be favorable to promoting the utilization ratio of first pole piece body, promote the energy density of electric core.

Drawings

Fig. 1 is a schematic structural diagram of a pole piece provided in an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view taken along the line B-B in FIG. 1;

fig. 3 is a schematic view of an explosion structure before a tab is welded to a battery cell provided in an embodiment of the present invention;

fig. 4 is a schematic diagram of an explosion structure of a first electrical core provided in an embodiment of the present invention;

fig. 5 is a schematic diagram of an explosion structure of a second electrical core provided in an embodiment of the present invention;

fig. 6 is a schematic structural view of a battery cell provided in an embodiment of the present invention after a tab is welded;

fig. 7 is an enlarged schematic view of a portion a in fig. 6.

Description of the reference numerals:

100-pole piece; 110-a first pole piece body; 111-a first notch; 112-a second gap; 120-a first connection tab; 130-a current collector; 140-an active material layer; 200-a first cell; 210-a first positive plate; 220-a first negative plate; 230-a first membrane; 231-third gap; 232-fourth gap; 300-a second cell; 310-a second positive plate; 320-a second negative plate; 330-a second membrane; 400-pole ear; 500-connecting piece.

Detailed Description

The technical solution of the present invention is clearly and exhaustively described below with reference to the accompanying drawings. In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In addition, in the description of the present invention, "at least one" means one or more unless specifically limited otherwise.

In the description of the present specification, the description of the term "on the basis of the above-described embodiments" means that a specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one preferred embodiment or preferred example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same implementation or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Referring to fig. 1, a first aspect of the present embodiment provides a pole piece 100, including a first pole piece body 110 and a first connection tab 120 located on one side of the first pole piece body 110 in the length direction, the first connection tab 120 is disposed in the first pole piece body 110 in a protruding manner, the first pole piece body 110 is provided with a first gap 111 and a second gap 112 arranged along the width direction of the first pole piece body 110, the first gap 111 and the second gap 112 are both located on one side edge of the first pole piece body 110 in the length direction, and the two second gaps 112 are respectively located on two opposite sides of the first connection tab 120 in the width direction of the first pole piece body 110.

The first connecting plate 120 may be connected to a tab, so that the pole piece 100 is electrically connected to an external circuit structure through the tab.

The pole piece that this embodiment provided, including first pole piece body and first connection piece, can make pole piece and utmost point ear connect through first connection piece, first breach and second breach have been seted up along width direction to first pole piece body, after a plurality of pole pieces are in turn and the dislocation is overlapped, connect first connection piece and utmost point ear and form electric core, be convenient for buckle first connection piece and utmost point ear through the second breach, and first connection piece and utmost point ear buckle the back and can hold in first breach, the occupation space of utmost point ear in the length direction of electric core has been reduced, electric core length direction's utilization ratio has been increased, be favorable to promoting the utilization ratio of first pole piece body, promote the energy density of electric core.

As shown in fig. 2, the pole piece 100 includes a paste coating area where the surface of the current collector 130 is coated with the active material layer 140, and a hollow foil area where the surface of the current collector 130 is not coated with the active material layer 140, where both opposite side surfaces of the first pole piece body 110 are the paste coating areas, both opposite side surfaces of the first connection piece 120 are the hollow foil areas, and the thickness of the first pole piece body 110 is greater than the thickness of the first connection piece 120, that is, both opposite side surfaces of the current collector 130 of the first pole piece body 110 are coated with the active material layer 140, and both opposite side surfaces of the current collector 130 of the first connection piece 120 are not coated with the active material layer 140, so that the active material layer 140 can be coated on the pole piece 100 to a greater extent to improve the energy density of the battery cell.

The electrode sheet 100 may be a positive electrode sheet, the electrode sheet 100 may also be a negative electrode sheet, if the active material layer 140 coated on the surface of the current collector 130 is a positive electrode active material layer, the electrode sheet 100 is a positive electrode sheet, and if the active material layer 140 coated on the surface of the current collector 130 is a negative electrode active material layer, the electrode sheet 100 is a negative electrode sheet; the material of the current collector 130 may be at least one of aluminum, copper, nickel, or an alloy thereof.

In this embodiment, the size of the first notch 111 along the width direction of the first pole piece body 110 is greater than the size of the first connection piece 120 along the width direction of the first pole piece body 110, and the size of the first notch 111 along the width direction of the first pole piece body 110 is greater than the size of the tab along the width direction of the first pole piece body 110, thereby ensuring that the first connection piece 120 and the tab are connected and bent, and can be accommodated in the first notch 111, thereby reducing the occupied space of the tab in the length direction of the battery cell, increasing the utilization rate of the battery cell in the length direction, and improving the energy density of the battery cell.

On the basis of the above embodiment, the size of the first notch 111 along the width direction of the first pole piece body 110 is greater than or equal to 4mm, and less than or equal to 70mm; the size of the first notch 111 along the length direction of the first pole piece body 110 is greater than or equal to 3mm and less than or equal to 30mm, that is, in fig. 1, W is greater than or equal to 4mm and less than or equal to 70mm, and L is greater than or equal to 3mm and less than or equal to 30mm, so that the first connecting piece 120 and the tab can be contained in the first notch 111 after being bent, and the problem that the energy density of the battery cell is influenced due to the overlarge size of the first notch 111 can be avoided.

It should be noted that the size of the first connection plate 120 in the width direction of the first pole piece body 110 may be slightly larger than the size of the tab in the width direction of the first pole piece body 110, or the size of the first connection plate 120 in the width direction of the first pole piece body 110 may be equal to the size of the tab in the width direction of the first pole piece body 110.

In this embodiment, the first connecting plate 120 is located between the two second gaps 112, one end of the first connecting plate 120 is connected to the first pole piece body 110 and located inside the first pole piece body 110, and the other end of the first connecting plate 120 is protruded along the length direction of the first pole piece body 110 and disposed on the first pole piece body 110, so that the second gaps 112 are respectively disposed at the two ends of the first connecting plate 120, which is convenient for the tab to be bent after being connected to the first connecting plate 120.

The size of the first notch 111 in the width direction of the first pole piece body 110 is greater than the size of the second notch 112 in the width direction of the first pole piece body 110, so that the problem that the energy density of the battery cell is affected due to the fact that the size of the second notch 112 is too large can be avoided.

On the basis of the above embodiment, the two second gaps 112 may have the same size, the size of each second gap 112 along the width direction of the first pole piece body 110 is greater than or equal to 0.1mm and less than or equal to 10mm, the size of each second gap 112 along the length direction of the first pole piece body 110 is greater than or equal to 3mm and less than or equal to 30mm, that is, W1 is greater than or equal to 0.1mm and less than or equal to 10mm in fig. 1, thereby avoiding the size of the second gap 112 from being too small, enabling the tab to contact with the active material layer 140, affecting the safety of the battery cell, and also avoiding the size of the second gap 112 from being too large and affecting the energy density of the battery cell.

In this embodiment, the shape of the first notch 111 may be one or a combination of several of a rectangle, a trapezoid, a U shape, a V shape, and a semicircle, and the shape of the second notch 112 may also be one or a combination of several of a rectangle, a trapezoid, a U shape, a V shape, and a semicircle, and those skilled in the art may set the shapes of the first notch 111 and the second notch 112 according to actual situations, preferably, the shape of the first notch 111 is a rectangle, and the shape of the second notch 112 is a rectangle.

As shown in fig. 3, a second aspect of the present embodiment provides a battery, which includes a first battery cell 200 and a second battery cell 300, wherein the first battery cell 200 and the second battery cell 300 are stacked on each other and can be bonded by applying pressure and heat to form a battery cell.

As shown in fig. 4, the first battery cell 200 includes a first positive electrode tab 210, a first negative electrode tab 220, and a first separator 230, wherein the first separator 230 is located between the first positive electrode tab 210 and the first negative electrode tab 220, and is used for electrically insulating the first positive electrode tab 210 from the first negative electrode tab 220; the first positive electrode sheet 210, the first separator 230, and the first negative electrode sheet 220 are alternately stacked to form the first cell 200, and the first positive electrode sheet 210 and the first negative electrode sheet 220 are both the electrode sheets shown in the first aspect.

The number of the first positive electrode tabs 210 may be one, the number of the first positive electrode tabs 210 may also be multiple, the number of the first negative electrode tabs 220 may be one, and the number of the first negative electrode tabs 220 may also be multiple; if the number of the first positive electrode tabs 210 and the number of the first negative electrode tabs 220 are both multiple, the multiple first positive electrode tabs 210 and the multiple first negative electrode tabs 220 are sequentially and alternately stacked in the thickness direction of the first battery cell 200, and a first separator 230 is disposed between every two adjacent first positive electrode tabs 210 and first negative electrode tabs 220, so that the first positive electrode tabs 210 and the first negative electrode tabs 220 are electrically insulated.

Referring to fig. 4, the first diaphragm 230 is provided with a third gap 231 and a fourth gap 232, and the third gap 231 and the fourth gap 232 are disposed along the width direction of the first diaphragm 230; first positive plate 210 and first negative pole piece 220 dislocation set in turn, and make the first connection piece on the first positive plate 210, the position one-to-one setting of first breach on third breach 231 and the first negative pole piece 220, first breach on the first positive plate 210, the position one-to-one setting of first connection piece on fourth breach 232 and the first negative pole piece 220, therefore, enable to have two first breachs that set up along its width direction on the first electric core 200, be convenient for with two utmost point ear connections opposite in polarity, two utmost point ears have been reduced the occupation space at the length direction of electric core, electric core length direction's utilization ratio has been increased, be favorable to promoting the energy density of electric core.

On the basis of the above embodiment, the size of the first notch (including the first notch on the first positive plate 210 and the first notch on the first negative plate 220) is greater than the size of the third notch 231, and the size of the first notch is greater than the size of the fourth notch 232, so that the first separator 230 can be ensured to cover the first positive plate 210 and the first negative plate 220, and the phenomenon that the first battery cell 200 is shorted due to the contact between the first positive plate 210 and the first negative plate 220 is avoided.

As shown in fig. 5, the second battery cell 300 includes a second positive electrode tab 310, a second negative electrode tab 320, and a second separator 330, where the second separator 330 is located between the first positive electrode tab 310 and the second negative electrode tab 320 and is used to electrically insulate the second positive electrode tab 310 from the second negative electrode tab 320; the second positive plate 310, the second diaphragm 330 and the second negative plate 320 are alternately stacked to form the second electrical core 300, the second positive plate 310 and the second negative plate 320 have the same structure, and the second positive plate 310 and the second negative plate 320 are both pole pieces of a conventional structure, the second diaphragm 330 is a pole piece of a conventional structure, that is, the second positive plate 310 and the second negative plate 320 do not have a first notch and a second notch, the second diaphragm 330 does not have a third notch and a fourth notch, specifically, the second positive plate 310 and the second negative plate 320 both include a second pole body and a second connecting piece, the second connecting piece is located on one side of the second pole body in the length direction, and the second connecting piece protrudes and is disposed on the second pole body, at least one surface of the second pole body is a paste coating area, opposite side surfaces of the second connecting piece are empty foil areas, and the thickness of the second pole body is greater than that of the second connecting piece.

In this embodiment, the second positive plate of the second electrical core 300 is a plate with a conventional structure, which is beneficial to increasing the coating amount of the active material layer on the second positive plate, so as to further increase the energy density of the electrical core.

The number of the second positive electrode plates 310 may be one, the number of the second positive electrode plates 310 may also be multiple, the number of the second negative electrode plates 320 may be one, and the number of the second negative electrode plates 320 may also be multiple; if the number of the second positive electrode tabs 310 and the second negative electrode tabs 320 is multiple, the multiple second positive electrode tabs 310 and the multiple second negative electrode tabs 320 are sequentially and alternately stacked along the thickness direction of the second battery cell 300, and a second separator 330 is disposed between every two adjacent second positive electrode tabs 310 and second negative electrode tabs 320, so that the second positive electrode tabs 310 and the second negative electrode tabs 320 are electrically insulated.

The second positive plates 310 and the second negative plates 320 are alternately arranged in a staggered manner, the second connecting pieces of the second positive plates 310 and the first connecting pieces of the first positive plates 210 are arranged in a one-to-one correspondence manner, the second connecting pieces of the second negative plates 320 and the first connecting pieces of the first negative plates 220 are arranged in a one-to-one correspondence manner, the second connecting pieces of the second positive plates 310 and the first connecting pieces of the first positive plates 210 are connected by welding, and the second connecting pieces of the second negative plates 320 and the first connecting pieces of the first negative plates 220 are connected by welding, so that the first positive plates 210 and the connecting pieces of the second positive plates 310 are connected, the first negative plates 220 and the connecting pieces of the second negative plates 320 are connected, a battery cell formed by combining the first battery cell 200 and the second battery cell 300 is provided with two connecting pieces, and the two connecting pieces can be respectively connected with two lugs with opposite in polarity, so as to lead out the positive and negative poles of the battery cell, and the current input and output of the battery cell are convenient.

As shown in fig. 6 and 7, the battery cell further includes a tab 400, the tab 400 includes two tabs 400 with opposite polarities, that is, a positive tab and a negative tab, after the first battery cell 200 and the second battery cell 300 are stacked to form the battery cell, the two first connecting plates, the two second connecting plates, and the two tabs 400 are all disposed in one-to-one correspondence with the two first notches 111, the two first connecting plates, the two second connecting plates are connected with the two tabs 400, and each first connecting plate, the second connecting plate, and the tab 400 is accommodated in one first notch 111 after being bent.

Specifically, the first connecting piece of the first positive plate 210, the second connecting piece of the second positive plate 310, and the positive tab are all arranged corresponding to one first notch 111, the first connecting piece of the first positive plate 210 and the second connecting piece of the second positive plate 310 are welded and connected to form one connecting piece 500, the connecting piece 500 is welded and connected to the positive tab, and the connecting piece 500 and the positive tab are bent and then accommodated in one first notch 111, that is, the first connecting piece of the first positive plate 210, the second connecting piece of the second positive plate 310 and the positive tab are welded and bent and then accommodated in one first notch 111;

the first connecting piece of the first negative plate 220, the second connecting piece of the second negative plate 320 and the negative tab are arranged corresponding to one first notch 111, the first connecting piece of the first negative plate 220 and the second connecting piece of the second negative plate 320 are welded to form another connecting piece 500, the connecting piece 500 is welded to the negative tab, and the connecting piece 500 and the negative tab are accommodated in the other first notch 111 after being bent, namely the first connecting piece of the first negative plate 220, the second connecting piece of the second negative plate 320 and the negative tab are welded to be connected and bent and are accommodated in the other first notch 111.

In this embodiment, the dimension of the first notch 111 in the width direction of the battery cell is greater than the dimension of the tab 400 in the width direction of the battery cell, and the dimension of the first notch 111 in the width direction of the battery cell is greater than the dimension of the second connecting piece in the width direction of the battery cell. From this, can guarantee that first connection piece, second connection piece and utmost point ear 400 can hold in first breach 111 after buckling, reduce utmost point ear 400 at the length direction's of electric core occupation space, increase electric core length direction's utilization ratio, promote the energy density of electric core.

In this embodiment, the thickness of the first connection plate is smaller than that of the first pole piece body, and the first notch 111 is disposed on the first pole piece body, so that after the first positive pole piece 210, the first separator 230, and the first negative pole piece 220 are alternately stacked to form the first battery cell 200, a step-shaped first notch 111 is formed between the first connection plate and the first pole piece body 110, and the step-shaped first notch 111 can accommodate the first connection plate, the second connection plate, and the tab 400 that are bent and welded.

On the basis of the above embodiment, the thickness of the first battery cell 200 is greater than or equal to the sum of the thicknesses of the tab 400, the first connecting sheet and the second connecting sheet, so that the tab 400, the first connecting sheet and the second connecting sheet after being bent can be contained in the first notch 111 of the first battery cell 200, and the tab 400, the first connecting sheet and the second connecting sheet after being bent are prevented from protruding out of the first battery cell 200 in the thickness direction of the battery cell to influence the energy density of the battery cell.

On the basis of the above embodiment, an adhesive paper layer (not shown in the figure) is disposed on a surface of the first battery cell 200, which is away from the second battery cell 300, and the adhesive paper layer covers the surface of the first notch 111, so that a burr at a position where the notch is disposed on the first pole piece body can penetrate through the casing or cause a short circuit phenomenon, thereby improving the safety performance of the battery.

The battery in this embodiment further includes a casing, the first battery cell 200 and the second battery cell 300 are stacked to form a battery cell, and the battery cell is encapsulated in the casing, two tabs 400 with opposite polarities (i.e., a positive tab and a negative tab) are respectively led out from the battery cell, and the two tabs 400 with opposite polarities are both located outside the casing, the tabs 400 are further provided with tab glue for sealing a gap between the casing and the tabs 400, where the casing is any one of an aluminum plastic film casing and an aluminum casing.

Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto. Various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present disclosure, and these changes and modifications are intended to fall within the scope of the present disclosure.

Claims

1. A pole piece is characterized by comprising a first pole piece body and a first connecting piece positioned on one side of the first pole piece body in the length direction, wherein the first connecting piece is convexly arranged on the first pole piece body;

2. The pole piece of claim 1, wherein the first gap has a dimension in the width direction that is greater than a dimension in the width direction of the first connection tab and/or the first gap has a dimension in the width direction that is greater than a dimension in the width direction of the second gap.

3. The pole piece of claim 1, wherein the first gap has a dimension in the width direction of greater than or equal to 4mm and less than or equal to 70mm, and/or the first gap has a dimension in the length direction of greater than or equal to 3mm and less than or equal to 30mm, and/or the second gap has a dimension in the width direction of greater than or equal to 0.1mm and less than or equal to 10mm.

4. The pole piece of claim 1, wherein the shape of the first notch is one or a combination of several of a rectangle, a trapezoid, a U-shape, a V-shape and a semicircle, and/or the shape of the second notch is one or a combination of several of a rectangle, a trapezoid, a U-shape, a V-shape and a semicircle.

5. A battery, comprising a first battery cell, wherein the first battery cell comprises at least one first positive plate and at least one first negative plate stacked on each other, a first separator is disposed between each adjacent first positive plate and first negative plate, and at least one first positive plate and at least one first negative plate are the pole pieces in any one of claims 1 to 4.

6. The battery according to claim 5, wherein a third notch and a fourth notch are provided in the first separator, and the third notch and the fourth notch are provided along a width direction of the first separator.

7. The battery according to claim 6, wherein the first positive plate and the first negative plate are alternately arranged in a staggered manner, and the first connecting piece of the first positive plate, the third notch and the first notch of the first negative plate are arranged in a one-to-one correspondence manner, and the first notch of the first positive plate, the fourth notch and the first connecting piece of the first negative plate are arranged in a one-to-one correspondence manner.

8. The battery of claim 6, further comprising a second cell, wherein the first cell and the second cell are stacked on each other to form a cell of the battery, the second cell comprises at least two second pole pieces that are stacked on each other and have opposite polarities, a second separator is disposed between every two adjacent second pole pieces, each second pole piece comprises a second pole piece body and a second connecting piece, the second connecting piece is located on one side of the second pole piece body in the length direction, and the second connecting piece is convexly disposed on the second pole piece body.

9. The battery of claim 8, further comprising two tabs with opposite polarities, wherein the two first connecting pieces, the two second connecting pieces and the two tabs are arranged in one-to-one correspondence with the two first notches, and each of the first connecting pieces, the second connecting pieces and the tabs is connected and bent to be accommodated in one of the first notches.

10. The battery of claim 9, wherein the first notch has a dimension in the width direction that is greater than a dimension of the tab in the width direction, and/or wherein the first notch has a dimension in the width direction that is greater than a dimension of the second tab in the width direction.

11. The battery of claim 9, wherein the thickness of the first cell is greater than or equal to the sum of the thicknesses of the tab, the first connecting tab, and the second connecting tab.

12. The battery of claim 9, wherein a gummed paper layer is disposed on a side surface of the first cell away from the second cell, and the gummed paper layer covers a surface of the first notch.