CN209880750U

CN209880750U - Winding type battery cell and lithium ion battery

Info

Publication number: CN209880750U
Application number: CN201920288726.8U
Authority: CN
Inventors: 翟传鑫; 徐子福; 严涛; 张明慧
Original assignee: Ambris (wuxi) Co Ltd
Current assignee: Ambris (wuxi) Co Ltd
Priority date: 2019-03-07
Filing date: 2019-03-07
Publication date: 2019-12-31
Anticipated expiration: 2029-03-07

Abstract

The utility model discloses a coiling type battery cell and lithium ion battery, including first electrode slice, second electrode slice, first utmost point ear, second utmost point ear, the length of the active material layer on the first mass flow body both sides is different, and each active material layer has a single face empty foil, and the empty foil of single face on the active material layer is the empty foil of first single face, and the empty foil of single face on the active material layer is the empty foil of second single face, and the empty foil of first single face and the empty foil of second single face are located the both ends of first mass flow body respectively; the active material layers on both sides of the second current collector have the same length and are continuous active material layers. Compared with the traditional winding type battery, the battery has the characteristics of small volume, light weight, material cost saving, high energy density, high specific energy, easy manufacture and the like, is suitable for being used as a power supply of consumer electronic products, energy storage systems and power systems, and is particularly suitable for electric equipment such as aircrafts, electric vehicles and the like which need large-current high-rate charging and discharging.

Description

Winding type battery cell and lithium ion battery

Technical Field

The invention relates to the technical field of lithium ion secondary batteries, in particular to a winding type battery cell and a lithium ion secondary battery containing the winding type battery cell.

Background

Lithium ion secondary batteries have the advantages of high voltage, high energy density, and the like, and are widely applied to power supplies of consumer electronics, energy storage systems, and power systems. Smaller size, lighter weight and larger capacity are always the development direction of lithium ion secondary batteries. In recent years, with the demand for electric devices requiring large-current high-rate charge and discharge, such as aircrafts and electric vehicles, lithium ion secondary batteries are required to have high charge and discharge rates and low resistance, and further, the lithium ion secondary batteries are required to be reduced in size, reduced in weight, and increased in capacity.

In order to prepare a high-rate lithium ion secondary battery, the following technical scheme is generally adopted:

the first technical solution is disclosed in patent documents CN104600250A and CN 105161673A: a plurality of tabs are welded on the electrode pole piece, and a protective adhesive tape is pasted at the welding position. The disadvantages of this method are: the tab is welded and the adhesive tape is pasted, so that the position of coating powder is occupied, and the capacity is smaller; the welded tab and the adhesive tape can increase the thickness of the battery and occupy the volume; needs to be welded for many times, and has poor reliability.

The second technical solution is disclosed in patent documents CN204885269U and CN 205543006U: and (3) remaining foil on one side or two sides of the electrode pole piece, cutting the position of the remaining foil into a proper shape and welding the remaining foil with the outer pole ear. In the practical implementation of the technical scheme and in the embodiment of the patent document, the powder materials on the two sides of the anode and the cathode are generally designed to be the same in length, after winding, part of the materials do not participate in the electrochemical reaction, the capacity cannot be exerted, the battery thickness and the battery weight are occupied in vain, and the material cost is wasted.

The third technical means is a combination of the first and second technical means, for example, patent document CN 204230364U.

A fourth technical solution is disclosed in patent document CN206921962U, in which a first electrode structure is shown in fig. 1, a second electrode structure is shown in fig. 2, and a wound structure is shown in fig. 3, which can save the thickness and weight of the battery, but the first electrode and the second electrode are both long and short sides with different lengths, that is, both need to be coated intermittently. The discontinuous coating has the disadvantages that the control variable is more, and the thickness at the beginning and the end is difficult to control; due to the tension problem of the fluid and the foil, the fluid shrinks during gap coating, the starting thickness and the ending thickness are easy to be over thick, and particularly when the head and the tail of the positive electrode are over thick, the capacity of the positive electrode is too high locally to cause lithium precipitation, so the head and tail thickness needs to be strictly controlled, and the manufacturing is complex.

The invention discloses a winding type battery cell and a lithium ion battery. Compared with the traditional winding type battery, the battery has the characteristics of small volume, light weight, material cost saving, high energy density, high specific energy, easy manufacture and the like, is suitable for being used as a power supply of consumer electronic products, energy storage systems and power systems, and is particularly suitable for electric equipment such as aircrafts, electric vehicles and the like which need large current and high-rate charging and discharging.

Disclosure of Invention

The invention aims to: provided are a winding type cell and a lithium ion secondary battery including the winding type cell.

The invention provides a winding type battery cell, the pole piece design of which is shown in fig. 4 and 5, the cross section of which is shown in fig. 6, the front view of which is shown in fig. 7-8, and the side view of which is shown in fig. 9-11, comprising:

a first electrode sheet: the current collector consists of a first current collector, an active substance layer A coated on one surface of the current collector and an active substance layer B coated on the other surface of the current collector;

a second electrode sheet: the current collector consists of a second current collector, an active substance layer C coated on one surface of the current collector and an active substance layer D coated on the other surface of the current collector;

and (3) isolation film: between the first electrode sheet and the second electrode sheet, separating them;

a first tab: the first current collector is connected with the first tab leading-out end;

a second lug: the second current collector is connected with a second tab leading-out end;

it is characterized in that:

one or more spaced first tab leading-out ends are left on one side or two sides of the first current collector;

one or more second pole lug leading-out ends at intervals are reserved on one side or two sides of the second current collector;

the lengths of the active material layers on the two sides of the first current collector are different, each active material layer is provided with a single-sided empty foil, the single-sided empty foil on the side where the active material layer A is located is a first single-sided empty foil, the single-sided empty foil on the side where the active material layer B is located is a second single-sided empty foil, and the first single-sided empty foil and the second single-sided empty foil are respectively positioned at the two ends of the first current collector;

the coating length of the active material layer coated on the two sides of the second current collector is the same, and the active material layer A is continuously coated. The advantages of continuous coating are: no redundant head and tail, and good thickness consistency.

By designing the distance between the plurality of tab leading-out ends, the tab winding machine can be provided with a plurality of first tab leading-out ends after winding and can be overlapped at the same position after winding; having a plurality of second pole ear terminals and overlapping in the same position after winding, as shown in fig. 7.

The first single-sided hollow foil is positioned at the end where the first electrode sheet starts to be wound (S1), that is, inside the winding core after being wound. The position of the second single-sided empty foil is located at the tail (E1) of the second electrode sheet after winding, that is, outside the winding core after winding.

For safety reasons, the negative electrode active material layer needs to completely cover the positive electrode active material layer to prevent lithium deposition by charging. Therefore, when designing and coating the pole piece: when the first electrode plate is a negative electrode plate and the second electrode plate is a positive electrode plate, the coating length of the active material layer A is greater than that of the active material layer C; the coating length of active material layer B is longer than that of active material layer D. The cut width of active material layer a and active material layer B is larger than the coating width of active material layer C and active material layer D, respectively. When the first electrode plate is a positive electrode plate and the second electrode plate is a negative electrode plate, the coating length of the active material layer A is smaller than that of the active material layer C; the coating length of active material layer B is smaller than that of active material layer D. The cut width of active material layer a and active material layer B is smaller than the coating width of active material layer C and active material layer D, respectively. In the wound battery core, the positions of the first single-sided hollow foil and the second single-sided hollow foil on the first current collector do not correspond to the active material layer C and the active material layer D on the second electrode sheet, so that the active material layer A and the active material layer B can completely cover the active material layer C and the active material layer D.

In addition to being thinner in the thickness direction, in the length direction of the battery core, we prefer to save space in the length direction by folding the tab welding position, so that the battery can be made smaller, as shown in fig. 7 and fig. 8: bending the part of the first tab leading-out end connected with the first tab, and folding the bent part in the thickness direction of the battery; the part of the second pole ear leading-out end connected with the second pole ear is folded to the thickness direction of the battery after being bent.

In addition, in the case of a particularly thick battery, one winding core may be difficult to achieve, and as shown in fig. 11, a plurality of winding cores may be connected to the same tab to form one battery cell.

The invention also provides a lithium ion battery, which comprises an outer package and one or more than one battery cell.

Comparing the three winding structures in fig. 3, fig. 6 and fig. 14, it can be seen that the positions of the second electrode sheet corresponding to the first electrode in the drawings, that is, the active materials that effectively contribute to the capacity, are all 8 single surfaces, that is, the design capacities of the cells shown in the three drawings are the same. On the basis, the thickness of the structure in the thickness direction is basically consistent with that of the structure in the figure 3 and the figure 6, and 4 first electrodes are added to the structure in the figure 14 compared with the structure in the figure 3 and the figure 6, so that the structure in the figure 3 and the figure 6 is lighter in weight and thinner in thickness.

Comparing the two winding structures of fig. 3 and fig. 6, it can be seen that the thickness and weight of the two winding structures are consistent at the end of the winding core, and further comparing the electrode designs, that is, comparing fig. 1, fig. 2 and fig. 4, fig. 5, it can be seen that fig. 1 and fig. 2 have 8 coating heads and tails, but fig. 4 and fig. 5 (because fig. 5 is continuous coating) have only 4 coating heads and tails, and the coating head and tail number of each battery is reduced by 50%, which significantly reduces the manufacturing difficulty.

Compared with the prior art, the invention has the advantages that: the energy-saving device is thin in thickness, small in length, light in weight, high in energy density and specific energy, capable of saving material cost, easy to manufacture, applied to aircrafts such as unmanned planes and the like and equipment such as electric automobiles, and capable of remarkably reducing weight, improving capacity, and improving endurance time and endurance mileage.

Drawings

Fig. 1 is a plan view and a cross-sectional view of a first electrode sheet (R1) of comparative example 1;

fig. 2 is a plan view and a cross-sectional view of a second electrode sheet (R2) of comparative example 1;

fig. 3 is a cross-sectional view of a wound cell of comparative example 1;

fig. 4 is a plan view and a cross-sectional view of the first electrode sheet (1);

fig. 5 is a plan view and a cross-sectional view of the second electrode sheet (2);

fig. 6 is a cross-sectional view of a wound cell;

fig. 7 is a front view of a wound cell;

figure 8 front view of the folded tab leading-out end of the winding type cell

Fig. 9 is a side view of a wound cell (corresponding to fig. 6);

fig. 10 side view of a folded tab lead-out end of a wound cell (corresponding to fig. 7)

Fig. 11 is a side view of a tab leading-out terminal folded after a plurality of winding cells (a first winding core and a second winding core) are connected.

Fig. 12 is a plan view and a cross-sectional view of a first electrode sheet (R1') of comparative example 2;

fig. 13 is a plan view and a sectional view of a second electrode sheet (R2') of comparative example 2;

fig. 14 is a cross-sectional view of a wound cell of comparative example 2;

description of the labeling:

r1 first electrode sheet of comparative example 1;

r11 comparative example 1 first current collector;

r12 comparative example 1 first active material layer (front side);

r13 comparative example 1 first active material layer (reverse side);

r14 empty foil side of the first electrode of comparative example 1;

r111 comparative example 1 first tab lead-out terminal;

RS1 winding start end of the first electrode sheet of comparative example 1;

RE1 comparative example 1 first electrode sheet winding end;

r2 second electrode sheet of comparative example 1;

r21 comparative example 1 second current collector;

r22 comparative example 1 second active material layer (front side);

r23 comparative example 1 second active material layer (reverse side);

r24 empty foil side of the second electrode of comparative example 1;

r211 comparative example 1 first tab lead-out terminal;

RS2 winding start end of the first electrode sheet of comparative example 1;

RE2 comparative example 1 first electrode sheet winding end;

1 a first electrode sheet;

11 a first current collector;

12 an active material layer A;

13 an active material layer B;

14 a first single-sided empty foil;

15 second single-sided dummy foil

111 a first tab leading-out end;

211 a second tab terminal;

22 an active material layer C;

23 an active material layer D;

s1 winding start end of the first electrode sheet;

e1 winding end of the first electrode sheet;

s2 winding start end of the first electrode sheet;

e2 winding end of the first electrode sheet;

r1' comparative example 1 first electrode sheet;

r11' comparative example 1 first current collector;

r12' comparative example 1 active substance layer a (front);

r13' comparative example 1 active material layer B (reverse);

r111' comparative example 1 first tab lead-out terminal;

RS 1' winding start end of the first electrode sheet of comparative example 1;

RE 1' comparative example 1 first electrode sheet winding end;

r2' comparative example 1 second electrode sheet;

r21' comparative example 1 second current collector;

r22' comparative example 1 active substance layer C (front);

r23' comparative example 1 active material layer D (reverse);

r211' comparative example 1 first tab lead-out terminal;

RS 2' winding start end of the first electrode sheet of comparative example 1;

RE 2' comparative example 1 first electrode sheet winding end;

3, a diaphragm;

r3 comparative example 1 separator;

r3' comparative example 2 separator;

4 a first tab;

and 5, a second tab.

Detailed Description

In order to make the technical problem, technical solution and advantageous effects solved by the present invention more clearly understood, the following description is given in conjunction with the accompanying drawings and embodiments to further explain the present invention in detail. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that the embodiments described herein may be practiced otherwise than as specifically illustrated or described herein.

A winding type battery cell, the pole piece design of which is shown in fig. 4 and 5, the cross-sectional view of which is shown in fig. 6, the front view of which is shown in fig. 7-8, and the side view of which is shown in fig. 9-11, comprises:

first electrode sheet 1: the active material layer comprises a first current collector 11, an active material layer A12 coated on one surface of the current collector and an active material layer B13 coated on the other surface of the current collector;

and 2, second electrode sheet: the active material layer comprises a second current collector 21, an active material layer C22 coated on one surface of the current collector and an active material layer D23 coated on the other surface of the current collector;

and (3) a separation film: between the first electrode sheet 1 and the second electrode sheet 2, separating them;

first tab 4: is connected with the first current collector 11 through a first tab leading-out end 111;

the second lug 5: is connected with the second current collector 21 through the second tab leading-out terminal 211;

it is characterized in that:

one or more spaced first tab leading-out ends 111 are left on one side or both sides of the first current collector 11;

one or more spaced second tab terminals 211 are left on one or both sides of the second current collector 21;

the lengths of the active material layers on the two sides of the first current collector 11 are different, each active material layer has a single-sided empty foil, the single-sided empty foil on the side where the active material layer A12 is located is a first single-sided empty foil 14, the single-sided empty foil on the side where the active material layer B13 is located is a second single-sided empty foil 15, and the first single-sided empty foil 14 and the second single-sided empty foil 15 are respectively located at the two ends of the first current collector 11;

the active material layer a12 is coated on both sides of the second current collector 21 with the same coating length and is continuously coated. The advantages of continuous coating are: no redundant head and tail, and good thickness consistency.

By designing the pitch of the tab leading-out ends, it is possible to have a plurality of first tab leading-out ends 111 after winding and overlap at the same position after winding; has a plurality of second tab terminals 211 and is overlapped in the same position after being wound, as shown in fig. 7.

The first single-sided hollow foil 14 is positioned at the end S1 where the first electrode sheet 1 starts to be wound, that is, inside the winding core after being wound. The second single-sided hollow foil 15 is positioned at a tail E1 of the second electrode sheet 2 after winding, that is, outside the winding core after winding.

For safety reasons, the negative electrode active material layer needs to completely cover the positive electrode active material layer to prevent lithium deposition by charging. Therefore, when designing and coating the pole piece: when the first electrode tab 1 is a negative electrode tab and the second electrode tab 2 is a positive electrode tab, the coating length of the active material layer a12 is greater than that of the active material layer C22; the coating length of active material layer B13 was longer than that of active material layer D23. The cut widths of active material layer a12 and active material layer B13 are larger than the coating widths of active material layer C22 and active material layer D23, respectively. When the first electrode sheet 1 is a positive electrode sheet and the second electrode sheet 2 is a negative electrode sheet, the coating length of the active material layer a12 is less than that of the active material layer C22; the coating length of active material layer B13 was smaller than that of active material layer D23. The cut widths of active material layer a12 and active material layer B13 are smaller than the coating widths of active material layer C22 and active material layer D23, respectively. In the wound cell, the positions of the first single-sided hollow foil 14 and the second single-sided hollow foil 15 on the first current collector 11 do not correspond to the active material layer C22 and the active material layer D23 on the second electrode sheet 2, so that the active material layer a12 and the active material layer B13 can completely cover the active material layer C22 and the active material layer D23.

In addition to being thinner in the thickness direction, in the length direction of the battery core, we prefer to save space in the length direction by folding the tab welding position, so that the battery can be made smaller, as shown in fig. 7 and fig. 8: bending the part of the first tab leading-out end 111 connected with the first tab 4 and then folding the bent part in the thickness direction of the battery; the portion of the second tab terminal 211 connected to the second tab 5 is bent and folded in the thickness direction of the battery.

Comparing the two winding structures of fig. 3 and fig. 6, it can be seen that the thickness and weight of the two winding structures are consistent at the end of the winding core, and further comparing the electrode designs, that is, comparing fig. 1, fig. 2 and fig. 4, fig. 5, it can be seen that fig. 1, fig. 2 have 8 coating heads and tails, but fig. 4, fig. 5 has only 4 coating heads and tails for continuous coating, and the coating head and tail number of each battery is reduced by 50%, which significantly reduces the manufacturing difficulty.

In the following examples, the first electrode tab was used as a negative electrode tab, and the second electrode tab was used as a positive electrode tab.

Description of the Battery production:

preparing a positive pole piece: adding a positive electrode active material lithium cobaltate and a binder polyvinylidene fluoride (PVDF) conductive agent Super-P into N-methylpyrrolidone (NMP) according to a weight ratio of 96:2:2, stirring and homogenizing to prepare positive electrode slurry; coating the two sides of the positive electrode slurry on a positive electrode current collector, and drying, compacting, cutting pieces and welding tabs to obtain the positive electrode piece.

Preparing a negative pole piece: adding artificial graphite serving as a negative electrode active material, Styrene Butadiene Rubber (SBR) and sodium carboxymethyl cellulose (CMC) into deionized water according to the proportion of 95:2.5:2.5, stirring and homogenizing to prepare negative electrode slurry; coating the two sides of the negative electrode slurry on a negative electrode current collector, and drying, compacting, slitting, cutting and welding tabs to obtain a negative electrode plate.

It should be noted that: in the following comparative examples and embodiments, the current collector foils were the same, the coating amounts per unit area of the positive and negative electrode sheets were the same, the coating widths of the positive and negative electrode sheets were the same, the numbers of the first tab lead-out terminal 111 and the second tab lead-out terminal 211 were the same, and the coating lengths were different according to the battery size and the design of different winding structures.

Preparing an electrolyte: lithium hexafluorophosphate with the concentration of 1M is selected as a lithium salt, and Ethylene Carbonate (EC): diethyl carbonate (DEC): ethyl Methyl Carbonate (EMC) was used as a solvent in a weight ratio of 30:30:40, and other performance-ensuring additives were also contained.

Preparing a lithium ion battery: assembling the negative pole piece and the positive pole piece prepared by the process with a diaphragm to prepare a battery cell, filling the battery cell into an aluminum plastic film flexible package, injecting electrolyte into the battery cell, sealing, pre-charging, and forming to prepare the lithium ion secondary battery.

Description of the test methods:

and (3) capacity testing: charging to 4.4V at 25 deg.C with 800mA current, constant voltage charging to current less than 80mA at 4.4V, standing for 5 min, and constant current discharging to 3.0V with 800mA current, wherein the discharge capacity is used as capacity.

The thickness, length, weight, etc. are measured according to known methods. The length is from the bottom of the battery core to the top end of the tab glue.

Comparative example 1

The lithium ion secondary battery is prepared by referring to the battery manufacturing description, the design of a negative electrode plate is shown in figure 1, the design of a positive electrode plate is shown in figure 2, the winding structure is shown in figure 3, and the welding assembly of a lug is shown in figures 7 and 9.

Comparative example 2

The lithium ion secondary battery is prepared according to the battery manufacturing description, the negative electrode sheet is designed as shown in figure 12, the positive electrode sheet is designed as shown in figure 13, the winding structure is shown in figure 14, and the lug is welded and assembled as shown in figures 7 and 9.

Example 1

The lithium ion secondary battery is prepared according to the battery manufacturing description, the negative electrode sheet is designed as shown in figure 4, the positive electrode sheet is designed as shown in figure 5, the winding structure is shown in figure 6, and the lug is welded and assembled as shown in figures 7 and 9.

Example 2

The lithium ion secondary battery is prepared according to the battery manufacturing description, the negative electrode sheet is designed as shown in figure 4, the positive electrode sheet is designed as shown in figure 5, the winding structure is shown in figure 6, and the lug is welded and assembled as shown in figures 8 and 10.

Comparative examples and each example 100 cells were fabricated, and the average values of capacity, thickness, length, and weight thereof were as shown in the following table.

From the experimental results, it can be seen that in example 1, compared with comparative example 2, the thickness is reduced by 0.2mm and the weight is reduced by about 3g under similar capacity and length, which corresponds to an increase in energy density of 7%.

Compared with the comparative example 1, the energy density of the example 1 is similar, but the head and tail quantity of the pole piece coating is 50 percent less, and the manufacturing difficulty is greatly reduced.

When the scheme of the folded pole ear leading-out end is selected more optimally (embodiment 2), the length of the battery is shorter, and the battery has more advantages in volume.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention in any form, and any skilled person familiar with the art will not depart from the technical scope of the present invention, and the technical spirit of the present invention will be any simple modification, equivalent replacement, and improvement made by the above embodiments, and the like, all still belong to the technical scope of the present invention.

Claims

1. A wound cell, comprising:

first electrode sheet (1): the current collector consists of a first current collector (11), an active material layer A (12) coated on one surface of the first current collector (11) and an active material layer B (13) coated on the other surface of the first current collector (11);

second electrode sheet (2): the current collector consists of a second current collector (21), an active material layer C (22) coated on one surface of the second current collector (21) and an active material layer D (23) coated on the other surface of the second current collector (21);

separator (3): the first electrode plate (1) and the second electrode plate (2) are positioned between the first electrode plate (1) and the second electrode plate (2) and are separated;

first tab (4): is connected with a first current collector (11) through a first tab leading-out end (111);

second tab (5): is connected with a second current collector (21) through a second tab leading-out end (211);

it is characterized in that:

one or more spaced first tab leading-out ends (111) are left on one side or two sides of the first current collector (11);

one or more second lug leading-out ends (211) at intervals are left on one side or two sides of the second current collector (21);

the active material layers on the two sides of the first current collector (11) are different in length, each active material layer is provided with a single-sided empty foil, the single-sided empty foil on the side where the active material layer A (12) is located is a first single-sided empty foil (14), the single-sided empty foil on the side where the active material layer B (13) is located is a second single-sided empty foil (15), and the first single-sided empty foil (14) and the second single-sided empty foil (15) are respectively located at the two ends of the first current collector (11);

the active material layers on both surfaces of the second current collector (21) have the same length and are continuous active material layers.

2. The wound cell of claim 1, wherein: the first electrode plate (1) is a negative electrode plate, and the second electrode plate (2) is a positive electrode plate.

3. The wound cell of claim 1, wherein: the position of the first single-sided hollow foil (14) is positioned at the end part of the first electrode sheet (1) at the beginning of winding, namely the first single-sided hollow foil is positioned in the winding core after winding; the position of the second single-sided hollow foil (15) is positioned at the tail of the second electrode sheet (2) after winding, namely, the second single-sided hollow foil is positioned outside the winding core after winding.

4. The wound cell of claim 2, wherein: the coating length and the cut width of the active material layer a (12) are larger than those of the active material layer C (22); the coating length and cut width of active material layer B (13) are larger than those of active material layer D (23).

5. The wound cell of claim 1, wherein: the first electrode plate (1) is a positive plate, and the second electrode plate (2) is a negative plate.

6. The wound cell of claim 5, wherein: the coating length and the cut width of the active material layer a (12) are smaller than those of the active material layer C (22); the coating length and the cut width of active material layer B (13) are smaller than those of active material layer D (23).

7. The wound cell of claim 2, wherein: in the wound battery core, the positions of the first single-sided hollow foil (14) and the second single-sided hollow foil (15) on the first current collector (11) do not correspond to the active material layer C (22) and the active material layer D (23) on the second electrode sheet (2), so that the active material layer A (12) and the active material layer B (13) can completely cover the active material layer C (22) and the active material layer D (23).

8. The wound cell of claim 1, wherein: the part of the first tab leading-out end (111) connected with the first tab (4) is bent and folded to the thickness direction of the battery; the part of the second pole ear leading-out end (211) connected with the second pole ear (5) is folded to the thickness direction of the battery.

9. The wound cell of claim 1, wherein: a plurality of first tab leading-out ends (111) are arranged and overlapped at the same position after being wound; has a plurality of second tab terminals (211) and is overlapped in the same position after winding.

10. A lithium ion battery is characterized by comprising an outer package and one or more coiled battery cells according to any one of 1-8.