WO2022152134A1

WO2022152134A1 - Electromagnetic interference-free battery cell, soft pack lithium battery and preparation method therefor

Info

Publication number: WO2022152134A1
Application number: PCT/CN2022/071424
Authority: WO
Inventors: 刘志明; 吴方余
Original assignee: 广东维都利新能源有限公司
Priority date: 2021-01-13
Filing date: 2022-01-11
Publication date: 2022-07-21
Also published as: CN112736294A

Abstract

Disclosed are an electromagnetic interference-free battery cell, a soft pack lithium battery and a preparation method therefor. The battery cell comprises a winding core body. The winding core body is formed by stacking and winding a rectangular first membrane, positive electrode plate, second membrane, negative electrode plate, and third membrane. A first aluminum plastic film is coated on the surface of the winding core body. One end of the positive electrode plate is connected to a positive electrode tab. The positive electrode tab is vertically led out from the length direction of the positive electrode plate. One end of the negative electrode plate is connected to a negative electrode tab. The negative electrode tab is vertically led out from the length direction of the negative electrode plate. The exposed extension part of the positive electrode tab and/or the negative electrode tab is vertically bent from the top surface or the bottom surface of the winding core body to the side surface, and forms at least one radial conductor in the radial direction of the winding core body. The structure and the preparation method of the present invention are simple, an electromagnetic field generated in the charging and discharging process can be reduced or counteracted, and the influences on the normal operation and precision of a precision component sensitive to the electromagnetic field can be avoided.

Description

A kind of electric core without electromagnetic interference, soft-pack lithium battery and manufacturing method thereof

technical field

The invention relates to the technical field of soft-packed lithium batteries, in particular to a battery cell without electromagnetic interference, a soft-packed lithium battery and a manufacturing method thereof.

Background technique

The outer packaging materials of lithium batteries are divided into soft packs and hard packs. Compared with hard packaging materials such as steel shells and aluminum shells, flexible packaging materials made of multi-layer films have the advantages of light weight, large capacity, high safety, Free choice of packaging shape and other advantages.

Soft-pack lithium batteries are generally installed inside components with small size, high precision and strict space constraints, such as mice, mobile phones and Bluetooth headsets.

During the charging and discharging process of the soft-pack lithium battery, the lithium battery itself will generate a weak electromagnetic field, and the interference to the equipment is generally not strong and can be ignored. Among the components, such as: Bluetooth headset, lithium battery will have certain interference and impact on the magnetic field of the speaker in the Bluetooth headset during the charging and discharging process, thereby affecting the playback quality of the Bluetooth headset, resulting in noise or noise, so a A kind of EMI-free battery and soft-pack lithium battery has positive significance.

technical solutions

The purpose of the present invention is to overcome the above-mentioned defects in the prior art, and to provide a battery cell without electromagnetic interference, a soft-packed lithium battery and a manufacturing method thereof. The soft-packed lithium battery has a simple structure and a manufacturing method, and can reduce or offset the Electromagnetic fields are generated during charging and discharging to avoid affecting the normal operation and accuracy of precision components that are sensitive to electromagnetic fields.

In order to achieve the above purpose, the present invention provides a battery core without electromagnetic interference, comprising a winding core body, the winding core body is composed of a rectangular first separator, a positive electrode sheet, a second separator, a negative electrode sheet and a third separator stacked and rolled. Winding, the surface of the core body is covered with a first aluminum plastic film, one end of the positive electrode is connected to the positive electrode tab, the positive electrode tab is vertically drawn from the length direction of the positive electrode, and one end of the negative electrode is connected to Negative tabs, the negative tabs are drawn vertically from the length direction of the negative sheet, and the positive tabs and/or the negative tabs are vertically bent from the top or bottom surface of the winding core body to the side in the exposed extension of the core body , and form at least one radial conductor along the radial direction of the core body.

Preferably, the positive electrode tab and the negative electrode tab are at the same height on the side of the winding core body after being bent, and the bent angle of the positive electrode tab and the negative electrode tab is between 0° and 180°.

Preferably, the positive electrode tab and the negative electrode tab are in the same position, and the included angle between the positive electrode tab and the negative electrode tab after bending is 180°.

Preferably, both the positive electrode tabs and the negative electrode tabs are located at the end of the rear section of the core body.

Preferably, the positive electrode tabs are aluminum-to-nickel tabs, the negative electrode tabs are nickel tabs, the positive electrode tabs are connected to the positive electrode sheet by welding, riveting or punching, and the negative electrode tabs are The ears are connected to the negative electrode sheet by welding or riveting or punching.

The present invention also provides a soft-packed lithium battery without electromagnetic interference, including the above-mentioned battery core without electromagnetic interference. The battery core body is formed by hot-pressing sealing molding, a sealing edge is formed between the second aluminum plastic film and the third aluminum plastic film, and the positive electrode tabs and the negative electrode tabs protrude from the inside of the battery core body.

Preferably, the connection between the positive electrode tab and the sealing edge is covered with positive electrode tab glue, and the connection between the negative electrode tab and the sealing edge is covered with negative electrode tab glue.

Preferably, the sealing edge is attached to the cell main body, the angle between the positive electrode tab and the axis of the cell main body is between 0° and 90°, and the negative electrode tab and the cell main body axis are between 0° and 90°. The angle between them is between 0°-90°.

The present invention also provides a method for producing the above-mentioned soft-pack lithium battery without electromagnetic interference, comprising the following steps:

Step S1: making pole pieces and welding pole tabs, cutting out rectangular positive pole pieces and negative pole pieces, welding the positive pole tabs vertically in the length direction of the positive pole pieces, and welding the negative pole tabs vertically in the length direction of the negative pole pieces;

Step S2: making the winding core body, stacking the rectangular first separator, the positive electrode sheet, the second separator, the negative electrode sheet and the third separator in sequence and then winding to form the winding core body;

Step S3: the winding core body is fixed, and the surface of the winding core body is covered with a circle of the first aluminum-plastic film;

Step S4: Bending the tabs, bending the positive tabs and/or the negative tabs vertically from the top surface or bottom surface of the reel body to the side on the exposed extension of the reel body, and forming at least one electrode along the radial direction of the reel body. direction radial conductor;

Step S5: the aluminum-plastic film is sealed, and the core body is placed between the second aluminum-plastic film and the third aluminum-plastic film, and the core body is formed by hot-pressing and sealing, and the second aluminum-plastic film and the third aluminum-plastic film are formed. A sealing edge is formed therebetween, and the positive electrode tab and the negative electrode tab protrude from the inside of the battery core body;

Step S6: injecting liquid, activating and resealing, injecting electrolyte into the core body, and after activating the core body, sealing and packaging again;

Step S7 : shaping and folding, trimming the shape of the main body of the battery cell through punching tooling, subtracting the excess aluminum-plastic film, bending the sealing edge in the axial direction, and the sealing edge is closely attached to the battery core body surface.

beneficial effect

1. The positive electrode tab and/or the negative electrode tab of the present invention are vertically bent from the top or bottom surface of the winding core body to the side at the exposed extension of the winding core body, and form at least one diameter along the radial direction of the winding core body. In the process of charging or discharging the lithium-ion battery, the horizontal electromagnetic field generated by the radial conductor is energized and the vertical electromagnetic field generated by the winding core body is perpendicular to each other, so that the magnetic field of the entire lithium-ion battery is reduced or cancelled. Avoid affecting the normal operation and accuracy of precision components that are sensitive to electromagnetic fields.

2. The invention adopts the method of stacking and winding to make the core body, the structure and the manufacturing method are simple, and the energy density of the lithium battery can be effectively improved, so that it is suitable for assembling on more flexible wearable electronic products.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic side view of a cross-sectional side view of a winding core body of a battery core without electromagnetic interference provided by the present invention;

2 is a schematic diagram of the other side of the cross section of the winding core body of a battery core without electromagnetic interference provided by the present invention;

3 is a schematic diagram of the connection between the positive electrode piece and the positive electrode tab of a cell without electromagnetic interference provided by the present invention;

4 is a schematic diagram of the connection between a negative electrode piece and a negative electrode tab of a cell without electromagnetic interference provided by the present invention;

5 is a front view of the winding core body tab of Embodiment 1 of a non-electromagnetic interference cell provided by the present invention after bending;

6 is a front view of the winding core body tab of Embodiment 2 of a non-electromagnetic interference cell provided by the present invention after bending;

7 is a bottom view of the winding core body tab of Embodiment 2 of a non-electromagnetic interference cell provided by the present invention after bending;

8 is a schematic diagram of the main structure of a battery cell of a soft-packed lithium battery without electromagnetic interference provided by the present invention;

9 is a front view of a main body of a battery cell of a soft-packed lithium battery without electromagnetic interference provided by the present invention;

FIG. 10 is a schematic structural diagram of the main body of a battery cell of a soft-packed lithium battery without electromagnetic interference provided by the present invention after shaping and folding.

Included in the diagram are:

31-first separator, 1-positive electrode sheet, 32-second separator, 2-negative electrode sheet, 33-third separator, 4-roll core body, 5-positive electrode tab, 91-positive electrode tab glue, 92-negative electrode Tab glue, 6-negative tab, 81-first aluminum-plastic film, 82-second aluminum-plastic film, 83-third aluminum-plastic film, 10-sealing edge, 7-cell main body, 11-radial conductor .

Embodiments of the present invention

The technical solutions in the present embodiment of the present invention will be described clearly and completely below with reference to the accompanying drawings in the present embodiment of the present invention. Obviously, the described embodiment is an embodiment of the present invention, but not all of them. this embodiment. Based on the present embodiment of the present invention, all other present embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Example 1

Referring to FIGS. 1 to 7 , a first embodiment of the present invention provides a cell without electromagnetic interference, including a winding core body 4 , as shown in FIGS. 1 and 2 , the winding core body 4 is composed of a rectangular first The separator 31 , the positive electrode sheet 1 , the second separator 32 , the negative electrode sheet 2 and the third separator 33 are stacked and wound. The winding core body 4 has a simple structure and a manufacturing method, and can effectively improve the energy density of the lithium battery, so as to be suitable for assembling on more flexible wearable electronic products.

As shown in FIG. 3 , one end of the positive electrode sheet 1 is connected to the positive electrode tab 5 , and the positive electrode tab 5 is vertically drawn out from the length direction of the positive electrode sheet 1 . As shown in FIG. 4 , one end of the negative electrode sheet 2 is connected to the negative electrode tab 6, the negative electrode tab 6 is drawn vertically from the length direction of the negative electrode sheet 2, and the positive electrode tab 5 and/or the negative electrode tab 6 is perpendicular to the top surface or bottom surface of the winding core body 4 in the exposed extension of the core body 4. Bend to the side, and form at least one radial conductor 11 along the radial direction of the core body 4 , so that during the charging or discharging process of the lithium ion battery, the electromagnetic field in the horizontal direction generated by the radial conductor 11 is energized and the core body 4 . The generated vertical electromagnetic fields are perpendicular to each other, so that the magnetic field of the entire lithium-ion battery is reduced or canceled, so as to avoid affecting the normal operation and accuracy of precision components that are sensitive to electromagnetic fields.

Further, in this embodiment, the radial conductor 11 is composed of the positive electrode tab 5 and/or the negative electrode tab 6 at the exposed extension of the core body 4 . In other embodiments, the The radial conductor 11 may be composed of a conductor that generates a strong magnetic field and has a relatively low resistance, and may be specifically installed between the positive electrode tabs 5 and/or the negative electrode tabs 6 .

Specifically, as shown in FIG. 5 , in the core body 4 , if the negative electrode tab 6 is longer than the positive electrode tab 5 , the vertical positive electrode tab 5 after being wound, first, along the radial direction of the core body 4 . The direction is to bend vertically to the side of the core body 4, specifically to the left or right, depending on the specific production situation. Secondly, after extending one end distance along the axial direction of the core body 4, vertical bending is performed again, so that The positive electrode tab 5 extends horizontally; the vertical negative electrode tab 6 after winding is firstly bent vertically to the side of the winding core body 4 along the radial direction of the winding core body 4. Because the negative electrode tab 6 is longer, the negative electrode tab The lugs 6 pass through the top surface of the winding core body 4 and are vertically bent to the side surfaces, and form radial conductors 11 along the radial direction of the winding core body 4 . Secondly, the negative electrode tabs 6 are perpendicular to the axial direction of the winding core body 4 Bending, again, after the negative electrode tab 6 extends one end distance along the axial direction of the core body 4, it is then bent vertically again, so that the negative electrode tab 6 extends horizontally; similarly, in the core body 4, If the positive electrode tab 5 is longer than the negative electrode tab 6, it can be bent according to the above principle.

Specifically, as shown in FIGS. 6 and 7 , in the core body 4, if the negative electrode tab 6 is longer than the positive electrode tab 5, the wound vertical positive electrode tab 5 and negative electrode tab 6 follow the winding core. The body 4 is bent vertically to the side of the core body 4 in the radial direction, specifically to the left or right, depending on the specific production situation. , perform vertical bending again, so that the positive electrode tab 5 extends horizontally; the negative electrode tab 6 extends along the axial direction of the winding core body 4 to the bottom of the winding core body 4. First, the negative electrode tab 6 extends from the winding core body 4 The bottom surface passes through and is bent vertically to the side, and forms a radial conductor 11 along the radial direction of the winding core body 4. Next, the negative electrode tabs 6 are vertically bent along the axial direction of the winding core body 4. Thirdly, the negative electrode After the tab 6 extends one end distance along the axial direction of the core body 4, it is bent vertically again, so that the negative tab 6 extends horizontally; similarly, in the core body 4, if the positive tab 5 is larger than the negative electrode The ears 6 are longer and can be bent according to the above principles.

Further, if the negative electrode tabs 6 and the positive electrode tabs 5 are in the middle of the winding core body 4 , the negative electrode tabs 6 and the positive electrode tabs 5 are respectively bent vertically to both sides to form the radial conductor 11 together.

The positive electrode tab 5 and the negative electrode tab 6 are at the same height on the side of the winding core body 4 after being bent. Since the positive electrode tab 5 and the negative electrode tab 6 are not limited to be in the same position, the positive electrode tab 5 and the negative electrode tab are not limited. The bent angle of the ear 6 is between 0° and 180°, which can be selected according to the actual situation, and is not limited by this embodiment.

As shown in Figures 5, 6 and 7, the positive electrode tab 5 and the negative electrode tab 6 are in the same position, and the angle between the positive electrode tab 5 and the negative electrode tab 6 after bending is 180°; As shown in FIG. 5 , the exposed extension of the negative electrode tab 6 is vertically bent from the top surface of the core body 4 to the side, and the angle between the positive electrode tab 5 and the negative electrode tab 6 after bending is 180°; As shown in FIGS. 6 and 7 , the exposed extension portion of the negative electrode tab 6 is vertically bent from the bottom surface of the core body 4 to the side surface, and the angle between the positive electrode tab 5 and the negative electrode tab 6 after bending is 180°.

Further, as shown in FIGS. 5 , 6 and 7 , the positive electrode tabs 5 and the negative electrode tabs 6 are located at the end of the rear section of the winding core body 4 .

The positive electrode tab 5 is an aluminum-to-nickel tab, the negative electrode tab 6 is a nickel tab, and the positive electrode tab 5 is connected to the positive electrode sheet 1 by welding or riveting or punching. The ears 6 are connected to the negative electrode sheet 2 by welding or riveting or punching.

The core body 4 can be installed inside a steel case battery or inside a soft-pack lithium battery.

Embodiment 2

Referring to FIGS. 8 to 10 , the second embodiment of the present invention provides a soft-packed lithium battery without electromagnetic interference, including the electromagnetic interference-free battery cell described in the first embodiment, and the winding core body 4 is The second aluminum-plastic film 82 and the third aluminum-plastic film 83 are covered up and down, and then hot-pressed and sealed to form the main body 7 of the battery cell. A sealing edge 10 is formed between the second aluminum-plastic film 82 and the third aluminum-plastic film 83 , so The positive electrode tabs 5 and the negative electrode tabs 6 protrude from the inside of the cell body 7 . The outer package of the present invention is an aluminum-plastic film outer package, which effectively reduces the overall weight of the lithium battery.

The connection between the positive electrode tab 5 and the sealing edge 10 is covered with positive electrode tab glue 91, the connection between the negative electrode tab 6 and the sealing edge 10 is covered with negative electrode tab glue 92, and the positive electrode tab 5 and the negative electrode are covered with a negative electrode tab glue 92. The tabs 6 can be in the same direction or in the opposite direction, which can be selected according to the actual situation, which is not limited by this embodiment.

The sealing edge 10 is attached to the main body 7 of the battery cell, and the sealing edge 10 and the main body 7 of the battery cell are closely attached to reduce the volume of the lithium battery and increase the unit density of the lithium battery.

The included angle between the positive electrode tab 5 and the axis of the cell body 7 is between 0° and 90°, and the angle between the negative electrode tab 6 and the axis of the cell body 7 is between 0° and 90°. Specifically, as shown in FIGS. 8 and 9 , the included angle between the positive electrode tab 5 and the axis of the cell body 7 is 90°, and the angle between the negative electrode tab 6 and the axis of the cell body 7 is 90°. The angle is 90°. As shown in FIG. 10 , the angle between the positive electrode tab 5 and the axis of the cell body 7 is 0°, and the angle between the negative electrode tab 6 and the axis of the cell body 7 is 0°, so that the positive electrode tab 5 and the negative electrode tab 6 can have a greater degree of freedom, so as to adapt to smaller precision components and make the application more extensive.

Embodiment 3

Embodiment 3 of the present invention provides a method for producing a soft-pack lithium battery without electromagnetic interference described in Embodiment 2, comprising the following steps:

Step S1: making pole pieces and welding pole tabs, cutting out rectangular positive pole pieces 1 and negative pole pieces 2, welding positive pole tabs 5 vertically in the length direction of positive pole piece 1, and welding negative pole tabs vertically in the length direction of negative pole piece 2 6.

Step S2 : making the winding core body 4 , stacking the rectangular first separator 31 , the positive electrode sheet 1 , the second separator 32 , the negative electrode sheet 2 and the third separator 33 in sequence and then winding the winding core body 4 .

Step S3 : the winding core body 4 is fixed, and the surface of the wound core body 4 is covered with a circle of the first aluminum-plastic film 81 .

Step S4: Bending the tabs, bending the positive tabs 5 and/or the negative tabs 6 at the exposed extension of the core body 4 from the top surface or bottom surface of the core body 4 to the side vertically, and forming at least one along the winding body 4. Radial conductors 11 in the radial direction of the core body 4 .

Step S5: The aluminum-plastic film is sealed, and the core body 4 is placed between the second aluminum-plastic film 82 and the third aluminum-plastic film 83, and the core body 7 is formed by hot-pressing sealing. The second aluminum-plastic film 82 and the third aluminum-plastic film 83 A sealing edge 10 is formed between the third aluminum plastic films 83 , and the positive electrode tabs 5 and the negative electrode tabs 6 protrude from the inside of the battery core body 7 .

Step S6 : injecting liquid, activating and resealing, injecting electrolyte into the core body 4 , and after activating the core body 4 , sealing and packaging again.

Step S7: shaping and folding, trimming the shape of the main body 7 of the battery cell by punching tooling, subtracting the excess aluminum-plastic film, bending the sealing edge 10 in the axial direction, and the sealing edge 10 is closely attached on the surface of the cell body 7 .

The above manufacturing method is simple to operate, greatly improves the manufacturing efficiency of the lithium battery, and improves the production quality of the lithium battery.

To sum up, the beneficial effects of the present invention are:

The positive electrode tabs 5 and/or the negative electrode tabs 6 of the present invention are vertically bent from the top or bottom surface of the core body 4 to the same height of the side at the exposed extension of the core body 4 , and at least one edge is formed along the core body 4 . The radial conductor 11 in the radial direction makes the horizontal electromagnetic field generated by the radial conductor 11 energized and the vertical electromagnetic field generated by the core body 4 perpendicular to each other during the charging or discharging process of the lithium ion battery, so that the entire lithium ion The magnetic field of the battery is reduced or canceled to avoid affecting the normal operation and accuracy of the precision components that are sensitive to the electromagnetic field; the invention adopts the method of stacking and winding to make the core body 4, the structure and the manufacturing method are simple, and can effectively improve the lithium ion The energy density of batteries for fitting into more flexible wearable electronics.

Claims

A battery core without electromagnetic interference, characterized by comprising a winding core body (4), and the winding core body (4) is composed of a rectangular first diaphragm (31), a positive electrode sheet (1), a second diaphragm (32) ), the negative electrode sheet (2) and the third diaphragm (33) are stacked and wound, the surface of the core body (4) is covered with a first aluminum plastic film (81), and one end of the positive electrode sheet (1) A positive electrode tab (5) is connected, the positive electrode tab (5) is drawn vertically from the length direction of the positive electrode sheet (1), one end of the negative electrode sheet (2) is connected to the negative electrode tab (6), and the negative electrode tab ( 6) Vertically drawn out from the length direction of the negative electrode sheet (2), the positive electrode tab (5) and/or the negative electrode tab (6) are exposed from the top of the core body (4) at the exposed extension of the core body (4). The surface or the bottom surface is vertically bent to the side surface, and forms at least one radial conductor (11) along the radial direction of the core body (4).
The battery core without electromagnetic interference according to claim 1, characterized in that the positive electrode tab (5) and the negative electrode tab (6) are at the same height on the side of the winding core body (4) after being bent, so The angle between the positive electrode tab (5) and the negative electrode tab (6) after bending is between 0° and 180°.
The battery cell without electromagnetic interference according to claim 2, characterized in that the positive electrode tab (5) and the negative electrode tab (6) are in the same position, and the positive electrode tab (5) and the negative electrode tab are in the same position. The included angle of the ears (6) after bending is 180°.
The battery core without electromagnetic interference according to claim 3, characterized in that both the positive electrode tabs (5) and the negative electrode tabs (6) are located at the end of the rear section of the winding core body (4).
The battery core without electromagnetic interference according to claim 1, characterized in that the positive electrode tab (5) is an aluminum-to-nickel tab, the negative electrode tab (6) is a nickel tab, and the The positive electrode tab (5) is connected to the positive electrode sheet (1) by welding, riveting or punching, and the negative electrode tab (6) is connected to the negative electrode sheet (2) by welding, riveting or punching.
A soft-packed lithium battery without electromagnetic interference, characterized in that it includes a battery core without electromagnetic interference according to any one of claims 1 to 5, and the core body (4) is covered by a second aluminum-plastic film (82) and the third aluminum-plastic film (83) are covered up and down and then hot-pressed and sealed to form the battery core body (7). The second aluminum-plastic film (82) and the third aluminum-plastic film (83) are formed between The sealing edge (10), the positive electrode tab (5) and the negative electrode tab (6) protrude from the inside of the battery core body (7).
A soft-packed lithium battery without electromagnetic interference according to claim 6, characterized in that the connection between the positive electrode tab (5) and the sealing edge (10) is covered with positive electrode tab glue (91), so The connection between the negative electrode tab (6) and the sealing edge (10) is covered with negative electrode tab glue (92).
A soft-packed lithium battery without electromagnetic interference according to claim 6, characterized in that the sealing edge (10) is attached to the main body (7) of the battery cell, and the positive electrode tab (5) is connected to the battery cell body (7). The included angle between the axes of the core body (7) is between 0° and 90°, and the included angle between the negative electrode tab (6) and the axis of the cell body (7) is between 0° and 90°.
A method for making a soft-pack lithium battery without electromagnetic interference according to any one of claims 1 to 8, characterized in that, comprising the following steps:

Step S1: Make pole pieces and welding pole tabs, cut out rectangular positive pole pieces (1) and negative pole pieces (2), weld the positive pole tabs (5) vertically in the length direction of the positive pole piece (1), and weld the positive pole pieces (5) on the negative pole piece ( 2) Weld the negative electrode tab (6) vertically in the longitudinal direction;

Step S2: making the core body (4), stacking the rectangular first separator (31), the positive electrode sheet (1), the second separator (32), the negative electrode sheet (2) and the third separator (33) in sequence and then Winding to form a core body (4);

Step S3: the winding core body (4) is fixed, and the surface of the wound winding core body (4) is covered with a circle of the first aluminum-plastic film (81);

Step S4: Bend the tabs, and bend the exposed extension of the positive tab (5) and/or the negative tab (6) on the core body (4) vertically from the top or bottom surface of the core body (4) to the side, and form at least one radial conductor (11) along the radial direction of the core body (4);

Step S5: The aluminum-plastic film is sealed, and the core body (4) is placed between the second aluminum-plastic film (82) and the third aluminum-plastic film (83), and the battery core body (7) is formed by heat-pressing and sealing. A sealing edge (10) is formed between the second aluminum-plastic film (82) and the third aluminum-plastic film (83). inside out;

Step S6: injecting liquid, activating and resealing, injecting electrolyte into the core body (4), and after activating the core body (4), sealing and packaging again;

Step S7; shaping and folding, trimming the shape of the main body (7) of the battery cell by punching out tooling, subtracting the excess aluminum-plastic film, and bending the sealing edge (10) in the axial direction, the sealing edge (10) is closely attached to the surface of the main body (7) of the battery cell.