阅读说明：本技术 一种软包扣式电芯的制作方法及软包扣式电池 (Manufacturing method of soft-package button type battery cell and soft-package button type battery ) 是由 陈国栋 余志� 罗敬 王传宝 陈杰 于子龙 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种软包扣式电芯的制作方法及软包扣式电池,制作方法包括以下步骤：步骤一、将极片与隔膜的一端部裁切一部分矩形区域,形成L型结构；步骤二、在正极片与负极片的空箔区分别焊接正极耳与负极耳；步骤三、按正极片、隔膜和负极片顺序依次卷绕,得到裸电芯,裸电芯包括第一卷芯与第二卷芯,第一卷芯的直径小于第二卷芯的直径；步骤四、将裸电芯的正极耳与负极耳弯折后放入冲切好的软包膜中进行封装,制得软包扣式电芯。本发明使极耳的弯折部分容纳在第一卷芯的侧面,不会突出于软包扣式电芯的软包膜表面,保证了裸电芯表面平整,同时在进行后工序制样或产品运输过程中,由于软包扣式电芯表面平整,避免了软包膜破损造成漏液的问题。(The invention discloses a manufacturing method of a soft-package button cell and a soft-package button cell, wherein the manufacturing method comprises the following steps: cutting a part of rectangular area at one end of the pole piece and the diaphragm to form an L-shaped structure; step two, respectively welding a positive electrode lug and a negative electrode lug on the empty foil areas of the positive electrode plate and the negative electrode plate; sequentially winding the positive plate, the diaphragm and the negative plate in sequence to obtain a naked electric core, wherein the naked electric core comprises a first winding core and a second winding core, and the diameter of the first winding core is smaller than that of the second winding core; and step four, bending the positive electrode tab and the negative electrode tab of the naked battery cell, and then putting the bent positive electrode tab and the bent negative electrode tab into a punched soft coating film for packaging to obtain the soft-coated buckle type battery cell. According to the invention, the bent part of the tab is accommodated on the side surface of the first winding core and does not protrude out of the surface of the soft packaging film of the soft packaging buckle type battery cell, so that the surface smoothness of a naked battery cell is ensured, and meanwhile, in the process of carrying out post-process sample preparation or product transportation, the surface smoothness of the soft packaging buckle type battery cell avoids the problem of liquid leakage caused by the damage of the soft packaging film.)

1. The manufacturing method of the soft-packaged button-type battery cell is characterized by comprising the following steps:

cutting a part of rectangular area at one end of the pole piece and the diaphragm to form an L-shaped structure;

step two, respectively welding a positive electrode lug and a negative electrode lug on the empty foil areas of the positive electrode plate and the negative electrode plate;

sequentially winding the positive plate, the diaphragm and the negative plate in sequence to obtain a bare cell, wherein the bare cell comprises a first winding core and a second winding core, and the diameter of the first winding core is smaller than that of the second winding core;

and step four, bending the positive electrode tab and the negative electrode tab of the naked battery cell, and then putting the bent positive electrode tab and the bent negative electrode tab into a punched soft coating film for packaging to obtain the soft-coated buckle type battery cell.

2. The method for manufacturing the soft-package button-type battery cell according to claim 1, wherein the L-shaped structure is prepared by die cutting or laser cutting the positive plate, the negative plate and the separator.

3. The method for manufacturing the soft-package button-type battery cell according to claim 1, wherein adhesive tape is pasted at the end of the winding of the second winding core.

4. The method for manufacturing the soft-package button-type battery cell according to claim 1, wherein the cut positive electrode sheet and the cut negative electrode sheet comprise a main body portion and a cutting portion, and the width of the cutting portion is smaller than that of the main body portion.

5. The manufacturing method of the soft-package button cell according to claim 4, wherein the empty foil area is arranged at any one of the cut part, the end part of the cut part or the area of the main body part close to the cut part.

6. The manufacturing method of the soft-package button-type battery cell according to claim 5, wherein when the empty foil area is arranged at the cutting part or the end part of the cutting part, the tab welded in the empty foil area is bent by 90 degrees in the vertical direction before packaging.

7. The method for manufacturing the soft-package button-type battery cell according to claim 5, wherein when the empty foil area is arranged in the area of the main body part close to the cutting part, the positive tab and the negative tab welded in the empty foil area are firstly folded back by 180 degrees in the vertical direction before being packaged, and then are folded by 90 degrees in the vertical direction.

8. The soft-package button cell is characterized by being prepared from the soft-package button cell of any one of claims 1-8 through baking, liquid injection, formation, secondary sealing and edge folding.

9. The pouch button cell according to claim 8, wherein the secondary seal comprises: carrying out centrifugal motion on the soft-packaged button-type battery cell to realize the separation of electrolyte and generated gas; vacuumizing the gas generated by the formation in the air bag, and refluxing the electrolyte to the soft-package button-type battery cell under the action of centrifugal force; and pre-sealing the side edge between the air bag and the soft-package button type battery cell.

10. The soft-packaged button cell according to claim 8, wherein the soft envelope is embossed before crimping to form a skirt structure.

Technical Field

The invention belongs to the technical field of batteries, and particularly relates to a manufacturing method of a soft-package button type battery cell and the soft-package button type battery.

Background

The lithium ion battery has the characteristics of high voltage of a self-discharge platform, small self-discharge, high energy density, no memory effect, environmental friendliness and the like, is an important power supply device at present, and is widely applied to various electronic equipment and vehicles. With the increasing portable devices and the smaller size of lithium ion batteries, button-type lithium ion batteries are specially used for such applications. The button cell refers to a small-sized lithium ion battery which is round or similar to a round and is similar to a button in shape, and can be mainly divided into a steel shell button cell and a soft package button cell. Laminate polymer button cell compares in steel-shelled button cell, has explosion-proof, and the security is high, and the size is nimble changeable, and the wide application is in fields such as TWS earphone, intelligence wearing product.

The naked electric core of current soft packet of button cell is convoluteed the back, and utmost point ear is located roll core one end, needs turn over 180 with utmost point ear earlier, buckles 90 again and just can carry out the plastic-aluminum membrane encapsulation, can produce 2 problems this moment: 1. when the tab is reversely folded for the first time, the tab is thick and hard, so that obvious bulges can be generated, and the risk of liquid leakage caused by puncturing the aluminum plastic film is generated; 2. this kind of structure utmost point ear is located naked electric core surface, and is more outstanding, has increased the diameter of electric core, and in carrying out back process system appearance or product transportation, this region very easily receives the exogenic action, leads to the plastic-aluminum membrane damaged, and then produces the weeping, and this kind of structure has produced very big hidden danger to soft packet of button cell's use. In addition, after the aluminum plastic film is sealed, the battery cell with the skirt edge structure is formed through embossing and folding, the occupied space of the skirt edge structure is large, and the energy density of the battery cell is reduced.

Disclosure of Invention

One of the objectives of the present invention is to provide a manufacturing method of a soft-package button cell and a soft-package button cell, in which an L-shaped structure is obtained by cutting a pole piece and a diaphragm, so that the diameter of the pole piece of a first winding core obtained after winding is smaller than that of a second winding core, and the bent portion of a tab is accommodated in the cut portion and does not protrude out of the surface of a soft-package film of a bare cell, thereby ensuring the surface of the bare cell to be flat, and avoiding liquid leakage caused by damage of the soft-package film during post-process sample preparation or product transportation.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention discloses a method for manufacturing a soft-packaged button type battery cell, which comprises the following steps:

cutting a part of rectangular area at one end of the pole piece and the diaphragm to form an L-shaped structure;

step two, respectively welding a positive electrode lug and a negative electrode lug on the empty foil areas of the positive electrode plate and the negative electrode plate;

sequentially winding the positive plate, the diaphragm and the negative plate in sequence to obtain a bare cell, wherein the bare cell comprises a first winding core and a second winding core, and the diameter of the first winding core is smaller than that of the second winding core;

and step four, bending the positive electrode tab and the negative electrode tab of the naked battery cell, and then putting the bent positive electrode tab and the bent negative electrode tab into a punched soft coating film for packaging to obtain the soft-coated buckle type battery cell.

Wherein, the pole piece with the diaphragm is through coiling the back, positive ear with the negative pole ear is in the side of naked electric core, first book core is by being cut the short part of back surplus the pole piece is convoluteed and is obtained, the second rolls up the core by not being cut the long part the pole piece is convoluteed and is obtained, first book core sets up the second rolls up core top, because the diameter of first book core is less than the diameter that the second rolled up the core, so positive ear with the negative pole ear can not be in through the part of buckling after buckling the surface of naked electric core causes the arch, has avoided the arch to receive exogenic action in carrying out back process system appearance or product transportation and has caused the flexible packaging film is damaged, and then produces the weeping, and the structure of naked electric core has improved space utilization and energy density simultaneously, flexible packaging film includes the plastic-aluminum membrane.

Specifically, the positive plate, the negative plate and the diaphragm are subjected to die cutting or laser cutting to prepare the L-shaped structure. The pole piece and the diaphragm can be accurately cut through die cutting and laser cutting.

Specifically, gummed paper is pasted at the tail end of the second winding core. Through the core is rolled up to the second and is pasted the adhesive tape in the ending department of rolling up the core, and the core is rolled up in the bundling that can be fine reduces the volume of naked electric core improves the energy density of naked electric core is at the encapsulation in-process, because the adhesive tape is puted up in ending department to naked electric core, can prevent to roll up the core in disorder, fine general naked electric core is put into in the soft diolame, production efficiency has been improved.

Specifically, the cut positive plate and the cut negative plate comprise a main body part and a cutting part, and the width of the cutting part is smaller than that of the main body part. Positive plate with obtain when the negative pole piece is convoluteed the diameter of naked electric core the first diameter of rolling up the core is less than the diameter of rolling up the core is rolled up to the second, and then can make positive ear and negative pole ear hold after buckling the side of first book core can not naked electric core surface causes the arch.

Specifically, the blank foil area is provided at any one of the cut portion, an end portion of the cut portion, or the main body portion near the cut portion area. The empty foil area is not coated with active slurry or the coated active slurry is cleaned, and the tab is welded in the empty foil area, so that the empty foil area is arranged at the position, and after the pole piece is wound, the tab is arranged on the side surface of the naked electric core.

Specifically, when the empty foil area is arranged at the cutting part or the end part of the cutting part, the tab welded in the empty foil area is bent for 90 degrees in the vertical direction before packaging. The tab is bent to prevent the tab from being punctured by the soft packaging film in the packaging process, and meanwhile, the tab adhesive bonded to the tab needs to be arranged between the two layers of soft packaging films.

Specifically, when the empty foil area is arranged in the area where the main body portion is close to the cutting portion, the positive electrode tab and the negative electrode tab welded in the empty foil area are firstly folded back by 180 degrees in the vertical direction before being packaged, and then are folded by 90 degrees in the vertical direction.

The invention also discloses a soft package button cell which is prepared by baking, injecting, forming, secondary sealing and folding the soft package button cell of any scheme. The soft-packaged button cell has the advantages that the energy density of the soft-packaged button cell is improved, meanwhile, the diameter of the second roll core is different from that of the first roll core, the tab passes through the bending part, the bending part can be bundled to form the first roll core by winding the cut part of the pole piece, the tab is packaged, the surface of the soft package film is not convex, the surface is smooth, and the problem of liquid leakage caused by damage of the soft package film in the process of post-process sample preparation or product transportation is avoided.

Further, the second seal includes: carrying out centrifugal motion on the soft-packaged button-type battery cell to realize the separation of electrolyte and generated gas; vacuumizing the gas generated by the formation in the air bag, and refluxing the electrolyte to the soft-package button-type battery cell under the action of centrifugal force; and sealing the side edge between the air bag and the soft-package button type battery cell. Through carrying out secondary sealing on the battery, removing the formation generated gas, the vacuum degree in the soft package button type battery cell is higher, and the pole piece is better attached.

Further, embossing is carried out on the soft envelope before edge folding to form a skirt structure. Behind the impressed watermark hem shirt rim structure with naked electric core the second rolls up the core diameter the same, and the line of extrusion is inwards rolled over, has reduced laminate button cell's volume has promoted battery energy density.

Compared with the prior art, the invention at least comprises the following beneficial effects: according to the invention, the L-shaped structure is obtained by cutting the pole piece and the diaphragm, so that the diameter of the first winding core obtained after winding is smaller than that of the second winding core, the bent part of the tab is accommodated on the side surface of the first winding core and cannot protrude out of the surface of the soft packaging film of the soft packaging buckle type battery cell, the surface smoothness of the soft packaging buckle type battery cell is ensured, liquid leakage caused by damage of the soft packaging film in the process of post-process sample preparation or product transportation is avoided, the diameter of the naked battery cell cannot be increased, and the energy density of the soft packaging buckle type battery cell is improved.

Drawings

Fig. 1 is a flow chart of a manufacturing method of a soft-package button-type battery cell of the present invention;

FIG. 2 is a schematic structural diagram of a cut pole piece according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a bare cell according to an embodiment of the present invention;

fig. 4 is a schematic structural view illustrating bending of a tab of a bare cell according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a soft capsule according to an embodiment of the present invention;

FIG. 6 is a schematic view of a heat seal configuration for a soft capsule according to one embodiment of the present invention;

fig. 7 is a schematic structural diagram of a soft-package button cell according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a cut pole piece according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a cut pole piece according to an embodiment of the invention;

fig. 10 is a schematic structural diagram of a bare cell according to an embodiment of the present invention;

fig. 11 is a schematic structural view illustrating bending of a tab of a bare cell according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a bare cell according to an embodiment of the present invention;

fig. 13 is a schematic structural view illustrating bending of a tab of a bare cell according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of a bare cell according to an embodiment of the present invention;

in the figure: 1-pole piece; 11-a body portion; 12-a cutting section; 13-empty foil areas; 2-naked electric core; 21-a first winding core; 22-a second winding core; 3, pole ear; 31-positive tab; 32-negative tab; 4-gummed paper; 5, soft coating; 51-pit punching; 52-air bag; 53-skirt construction; 6-soft package button cell.

Detailed Description

The present invention will be further described below with reference to the accompanying drawings for easier understanding, but the present invention can be implemented in various forms, and is not limited to the embodiments described herein and does not constitute any limitation to the present invention.

Example 1

As shown in fig. 1 to 7, the coating, rolling and cutting of the positive and negative electrode plates are firstly completed, the main body portion 11 and the cutting portion 12 are obtained by die cutting or laser cutting the positive and negative electrode plates and the diaphragm, the width of the cutting portion 12 is smaller than that of the main body portion 11, the main body portion 11 and the cutting portion 12 form an L-shaped structure as shown in fig. 2, the main body portion 11 is completely coated with active material slurry, the cutting portion 12 is set to be an empty foil area 13, the empty foil area 13 is an uncoated active slurry or a cleaned electrode plate 1 of the active slurry and is used for welding a tab 3, an aluminum tab is welded on the empty foil area 13 of the positive electrode plate to serve as a positive electrode tab 31, and a nickel tab is welded on the empty foil area 13 of the negative electrode plate to serve as a negative electrode tab 32.

As shown in fig. 3, winding positive plate, diaphragm and negative plate in proper order and forming a naked electric core 2, naked electric core 2 divide into two parts from top to bottom, and upper portion is first book core 21, and the lower part is the second and rolls up core 22, and first volume, the diameter of 21 are less than the diameter that the core 22 was rolled up to the second, roll up the core 22 at the second of naked electric core 2 and roll up the winding ending department and paste adhesive tape 4.

As shown in fig. 4, the positive tab 31 and the negative tab 32 of the bare cell 2 are respectively bent by 90 ° in the vertical direction.

As shown in fig. 5, due to the difference in diameter between the first winding core 21 and the second winding core 22, the aluminum plastic film as the soft envelope 5 is punched to form two circular pits of different sizes to obtain punched pits 51.

As shown in fig. 6, the bare cell 2 is placed in the aluminum plastic film punched hole 51, and is subjected to heat sealing, so as to obtain a soft-packaged button-type cell. And baking, injecting, forming, secondary sealing, embossing and folding the soft-package button cell to obtain the soft-package button cell 6 with the skirt structure 52 shown in fig. 7.

Wherein, two seal includes: carrying out centrifugal motion on the soft-packaged button-type battery cell to realize the separation of the electrolyte and the generated gas; vacuumizing the gas generated by the formation in the air bag 52, and refluxing the electrolyte to the soft-package button-type battery cell under the action of centrifugal force; and sealing the side edge between the air bag 52 and the soft-packaging button-type battery cell. The shirt rim structure behind the impressed watermark hem is the same with naked electric core 2's the second roll up core 22 diameter, and the line of extrusion is inwards rolled over, has reduced soft packet of button cell 6's volume, has promoted battery energy density.

Example 2

Unlike embodiment 1, as shown in fig. 8, the end of the cut part 12 of the present embodiment is provided with a blank foil area 13 for welding the tab 3.

The rest of the process is completely the same as that of the embodiment 1, and the description is omitted.

Example 3

Unlike embodiment 1, this embodiment sets the area of the main body portion 11 near the cut portion 12 as a blank foil area 13 for welding the tab 3, as shown in fig. 9. An aluminum tab is welded on the positive plate to serve as a positive tab 31, a nickel tab is welded on the negative plate to serve as a negative tab 32, and then the positive and negative plates and the diaphragm are wound together to obtain the bare cell 2 shown in fig. 10. As shown in fig. 11, the positive tab 31 and the negative tab 32 on the side surface of the first winding core 21 are bent, the positive tab 31 and the negative tab 32 which exceed the upper surface of the first winding core 21 are bent at 180 ° in the vertical direction, and the positive tab 31 and the negative tab 32 at the bent portions are bent at 90 ° in the vertical direction.

The rest of the process is completely the same as that of the embodiment 1, and the description is omitted.

Example 4

Unlike example 1, the end of the cut portion 12 of the positive electrode sheet of this example was provided with the empty foil region 13 as shown in fig. 8, the main body portion 11 of the negative electrode sheet was provided with the empty foil region 13 in the region near the cut portion 12 as shown in fig. 9, an aluminum tab was welded to the positive electrode sheet as the positive electrode tab 31, a nickel tab was welded to the negative electrode sheet as the negative electrode tab 32, and the positive and negative electrode sheets were wound together with the separator to obtain the bare cell 2 shown in fig. 12. As shown in fig. 13, the positive tab 31 that exceeds the upper surface of the second winding core 22 is bent at 90 ° in the vertical direction, the negative tab 32 that exceeds the upper surface of the first winding core 21 is bent at 180 ° in the vertical direction, and the negative tab 32 that is bent at the reverse angle is bent at 90 ° in the vertical direction.

The rest of the process is completely the same as that of the embodiment 1, and the description is omitted.

Example 5

Unlike example 4, in this example, as shown in fig. 8, the end of the cut portion 12 of the negative electrode sheet was set as the empty foil region 13, as shown in fig. 9, the main body portion 11 of the positive electrode sheet was set as the empty foil region 13 in the region near the cut portion 12, one aluminum tab was welded to the positive electrode sheet as the positive electrode tab 31, one nickel tab was welded to the negative electrode sheet as the negative electrode tab 32, and then the positive and negative electrode sheets were wound together with the separator to obtain the bare cell 2 shown in fig. 14.

The rest of the process is completely the same as that of embodiment 4, and is not described herein again.

The foregoing is a more detailed description of the present application in connection with specific embodiments thereof, and it is not intended that the present application be limited to the specific embodiments thereof. It will be apparent to those skilled in the art from this disclosure that many more simple derivations or substitutions can be made without departing from the inventive concepts herein.