CN219246887U

CN219246887U - Battery cell

Info

Publication number: CN219246887U
Application number: CN202320604833.3U
Authority: CN
Inventors: 朱炳阳; 金柱�; 安建; 于子龙; 陈杰; 郑明清
Original assignee: Zhejiang Liwei Energy Technology Co ltd
Current assignee: Zhejiang Liwei Energy Technology Co ltd
Priority date: 2023-03-23
Filing date: 2023-03-23
Publication date: 2023-06-23
Anticipated expiration: 2033-03-23

Abstract

The utility model discloses a battery cell, comprising: the device comprises a first pole piece, a second pole piece, a diaphragm and an insulator, wherein the first pole piece, the diaphragm and the second pole piece are sequentially overlapped, and the insulator is positioned in a first local area of one side of the diaphragm facing the first pole piece or in a second local area of one side of the diaphragm facing the second pole piece; the first pole piece and the second pole piece are always separated in the first local area or the second local area. The first local area or the second local area is divided from the part of the diaphragm, then the insulator is placed in the first local area or the second local area, so that the insulator exists between the first pole piece and the second pole piece except the diaphragm, after the diaphragm is heated and contracted, the insulator can bear higher temperature, so that the first pole piece and the second pole piece can be separated from each other instead of the diaphragm, the phenomenon that the first pole piece and the second pole piece are in direct contact to cause short circuit and fire is avoided, and the service life and the use safety of the battery cell are greatly improved.

Description

Battery cell

Technical Field

The utility model relates to the technical field of lithium batteries, in particular to a battery cell.

Background

Lithium ion batteries are currently popular energy storage products with a wide range of applications, and have the advantages of small self-discharge, long cycle life, large specific energy and the like. The battery core is a relatively core component in the lithium ion battery and is also a key point of battery charge and discharge, so that the quality assurance of the battery core is related to the quality problem of the whole battery.

The conventional battery cell comprises a positive plate, a negative plate and a diaphragm, wherein the diaphragm is positioned between the positive plate and the negative plate, and the positive plate and the negative plate are wound after being overlapped, and the positive plate and the negative plate are separated through the diaphragm, so that the phenomenon of short circuit caused by direct contact of the positive plate and the negative plate is avoided. During practical application, no matter in the stage of detecting the battery cell or in the stage of using, the condition that the battery cell is heated too high to cause the diaphragm to shrink exists, and the positive plate and the negative plate are in direct contact after the diaphragm is shrunk, so that short circuit is caused and fire disaster is caused, and great potential safety hazard exists.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model provides a battery cell.

The utility model discloses a battery cell, comprising: the device comprises a first pole piece, a second pole piece, a diaphragm and an insulator, wherein the first pole piece, the diaphragm and the second pole piece are sequentially overlapped, and the insulator is positioned in a first local area of one side of the diaphragm facing the first pole piece or in a second local area of one side of the diaphragm facing the second pole piece;

the first pole piece and the second pole piece are always separated in the first local area or the second local area.

According to an embodiment of the utility model, the width of the insulator is equal to the width of the first pole piece or the width of the insulator is equal to the width of the second pole piece.

According to an embodiment of the present utility model, at least one end of the insulator extends along the end of the first pole piece in the width direction and is exposed.

According to one embodiment of the utility model, the width of the insulator exposure is 0.2-2mm.

According to one embodiment of the utility model, the diaphragm has a first partial region and a second partial region, and the first partial region and the second partial region are provided with insulators.

According to one embodiment of the utility model, the first pole piece, the diaphragm and the second pole piece are wound to form a core, and the insulator is located at the innermost layer of the core.

According to one embodiment of the utility model, the length of the innermost layer of the core is greater than the length of the insulator.

According to one embodiment of the utility model, in the length direction, one side of the insulator is in contact with one side of the innermost layer of the core, and the other side of the insulator is spaced from the other side of the innermost layer of the core.

According to one embodiment of the utility model, in the length direction, both sides of the insulator are spaced from both sides of the innermost layer of the core.

According to one embodiment of the utility model, the spacing between the insulator and the core is 0.5-1.5mm.

The utility model has the beneficial effects that: the first local area or the second local area is divided from the part of the diaphragm, then the insulator is placed in the first local area or the second local area, so that the insulator exists between the first pole piece and the second pole piece except the diaphragm, after the diaphragm is heated and contracted, the insulator can bear higher temperature, so that the first pole piece and the second pole piece can be separated from each other instead of the diaphragm, the phenomenon that the first pole piece and the second pole piece are in direct contact to cause short circuit and fire is avoided, and the service life and the use safety of the battery cell are greatly improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

FIG. 1 is one of the cross-sectional views of a cell;

FIG. 2 is a second cross-sectional view of the cell;

FIG. 3 is one of the side schematic views of the battery cell;

FIG. 4 is a second schematic side view of the battery cell;

FIG. 5 is a third cross-sectional view of the cell;

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

Reference numerals illustrate:

1-a first pole piece;

2-a second pole piece;

3-a separator; 31-a first local area; 32-a second local area;

4-insulator;

5-core;

6-negative electrode ear;

7-positive electrode lug.

Detailed Description

Various embodiments of the utility model are disclosed in the following drawings, in which details of the practice are set forth in the following description for the purpose of clarity. However, it should be understood that these practical details are not to be taken as limiting the utility model. That is, in some embodiments of the utility model, these practical details are unnecessary. Moreover, for the purpose of simplifying the drawings, some conventional structures and components are shown in the drawings in a simplified schematic manner.

In addition, the descriptions of the "first," "second," and the like, herein are for descriptive purposes only and are not intended to be specifically construed as order or sequence, nor are they intended to limit the utility model solely for distinguishing between components or operations described in the same technical term, but are not to be construed as indicating or implying any relative importance or order of such features. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

Example 1

As shown in fig. 1, 2 and 3, fig. 1 is one of the cross-sectional views of the battery cell; FIG. 2 is a second cross-sectional view of the cell; fig. 3 is one of the side schematic views of the cell. The battery cell of this application includes first pole piece 1, second pole piece 2, diaphragm 3 and insulator 4, and first pole piece 1, diaphragm 3 and second pole piece 2 stack in order, and the back that stacks is accomplished and is coiled and form core 5, and wherein, insulator 4 sets up in one side of diaphragm 3, and insulator 4 can set up in one side of diaphragm 3 towards first pole piece 1, or set up insulator 4 in one side of diaphragm 3 towards second pole piece 2.

In a specific application, the diaphragm 3 is provided with a first local area 31, and the insulator 4 is arranged in the first local area 31; the first partial region 31 refers to a partial region of the separator 3 included in the side facing the first pole piece 1, that is, the first partial region 31 is only a partial region of the separator 3, and is not the entire side of the separator 3 facing the first pole piece 1. Since the insulating sheet is located in the first partial region 31, even if the separator 3 in the first partial region 31 is shrunk by heat, the insulating sheet in the first partial region 31 can still separate the first pole piece 1 from the second pole piece 2, and cannot be in direct contact.

Further, in the width direction of the core 5, one end of the insulator 4 extends in a direction away from the first pole piece 1, that is, one end of the insulator 4 protrudes from one end of the first pole piece 1, that is, the protruding end of the insulator 4 is exposed from the end of the entire cell. Specifically, the width of the portion of the insulator 4 protruding in the width direction of the core 5 is 0.2 to 2mm. Similarly, one end of the insulator 4 protrudes from one end of the second pole piece 2. The protruding part of the insulator 4 can further ensure that the first pole piece 1 and the second pole piece 2 cannot be in direct contact, and further prevent the phenomenon of short circuit of the battery cell.

Further, the first partial region 31 is located in the innermost layer of the core 5, and the insulator 4 is also located in the innermost layer of the core 5. The innermost layer refers to the layer of the core 5 having the smallest inner diameter. Because the first pole piece 1 and the second pole piece 2 do not contain active material layers at the initial winding end, the area of the insulator 4 covering the active material layers can be greatly reduced by placing the insulator 4 on the innermost layer of the core body 5, and the energy density of the battery core is not affected. Preferably, there is a space between the two sides of the insulator 4 and the two sides of the innermost layer of the core 5 in the length direction of the core 5, that is, the two sides of the insulator 4 and the two sides of the innermost layer of the core 5 are spaced apart, and it is known that the length of the innermost layer of the core 5 is greater than the length of the two sides of the insulator 4. Specifically, the interval between one side of the insulator 4 and one side of the innermost layer of the core 5 is 0.5 to 1.5mm.

When the novel chamfering machine is specifically applied, the insulator 4 is of a sheet structure, edges of the insulator 4 facing two sides of the innermost layer of the core body 5 are chamfered, and damage to the core body 5 caused by the edges is avoided.

In this embodiment, the insulator 4 needs to have a certain elastic property, deformability and high temperature resistance, such as vulcanized rubber, acrylic rubber sheet or silica gel sheet, the thickness of the insulator 4 is greater than or equal to 8 μm, and the high temperature that the insulator 4 can withstand is 180 ℃. The first pole piece 1 is a negative pole piece, and the second pole piece 2 is a positive pole piece. In addition, the battery cell further comprises a negative electrode lug 6 and a positive electrode lug 7, wherein the negative electrode lug 6 is arranged on the first pole piece 1, and the positive electrode lug 7 is arranged on the second pole piece 2.

Example two

As shown in fig. 4, fig. 4 is a second schematic side view of the battery cell. The difference between this embodiment and the first embodiment is that: both ends of the insulator 4 protrude from both ends of the first pole piece 1, and the specific structure thereof is described above and will not be described herein.

Example III

The difference between this embodiment and the first embodiment is that: one side of the insulator 4 is in contact with one side of the innermost layer of the core 5, and the other side of the insulator 4 is spaced from the other side of the innermost layer of the core 5.

Example IV

The difference between this embodiment and the first embodiment is that: both sides of the insulator 4 are in contact with both sides of the innermost layer of the core 5.

Example five

The difference between this embodiment and the first embodiment is that: in the width direction of the core 5, both ends of the insulator 4 are flush with both ends of the first pole piece 1, i.e., the width of the insulator 4 is equal to the width of the first pole piece 1. Similarly, the two ends of the insulator 4 are flush with the two ends of the second pole piece 2.

Example six

As shown in fig. 5, fig. 5 is a third cross-sectional view of the cell. The difference between this embodiment and the first embodiment is that: the diaphragm 3 is provided with a second partial region 32, and the insulator 4 is arranged in the second partial region 32; the second partial region 32 refers to a partial region of the separator 3 included in the side facing the second pole piece 2, that is, the second partial region 32 is only a partial region of the separator 3, and is not the entire side of the separator 3 facing the second pole piece 2. Since the insulating sheet is located in the second partial region 32, even if the separator 3 in the second partial region 32 is shrunk by heat, the insulating sheet in the second partial region 32 can still separate the first pole piece 1 from the second pole piece 2, and cannot be in direct contact.

Example seven

As shown in fig. 6, fig. 6 is a cross-sectional view of the battery cell. The present embodiment differs from the first embodiment in that the diaphragm 3 has both the first partial region 31 and the second partial region 32, and the insulator 4 is disposed in both the first partial region 31 and the second partial region 32 correspondingly.

Example eight

The difference between this embodiment and the first embodiment is that: the first local area 31 is not located in the innermost layer of the core 5, but is located in other folds of the first pole piece 1 or the second pole piece 2, and in specific applications, the first local area 31 may be set according to the area where the core 5 is heated at a higher temperature.

Example nine

The difference between this embodiment and the seventh embodiment is that: the first local area 31 and the second local area 32 are not located in the innermost layer of the core 5, but are located in other folds of the first pole piece 1 and the second pole piece 2, and in specific application, the first local area 31 can be set according to the area with higher heating temperature of the core 5.

Examples ten

The difference between this embodiment and the first embodiment is that: the first pole piece 1, the diaphragm 3 and the second pole piece 2 are sequentially stacked, that is, the core body 5 is formed by stacking, at this time, the core body 5 has no innermost layer, and in the length direction, the length of the insulator 4 is smaller than the length of the first pole piece 1, or the length of the insulator 4 is smaller than the length of the second pole piece 2.

In summary, the first local area 31 or the second local area 32 is divided from the part of the diaphragm 3, and then the insulator 4 is placed in the first local area or the second local area 32, so that the insulator 4 is arranged between the first pole piece 1 and the second pole piece 2 in addition to the diaphragm 3, and after the diaphragm 3 is heated and contracted, the insulator 4 can bear higher temperature, so that the diaphragm 3 can be replaced to always separate the first pole piece 1 from the second pole piece 2, the phenomenon that the first pole piece 1 and the second pole piece 2 are in direct contact to cause short circuit and fire is avoided, and the service life of the battery cell and the use safety are greatly improved.

The foregoing description is only illustrative of the utility model and is not to be construed as limiting the utility model. Various modifications and variations of the present utility model will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, or the like, which is within the spirit and principles of the present utility model, should be included in the scope of the claims of the present utility model.

Claims

1. A cell, comprising: the device comprises a first pole piece (1), a second pole piece (2), a diaphragm (3) and an insulator (4), wherein the first pole piece (1), the diaphragm (3) and the second pole piece (2) are sequentially overlapped, the insulator (4) is positioned in a first local area (31) of the diaphragm (3) facing one side of the first pole piece (1), or the insulator (4) is positioned in a second local area (32) of the diaphragm (3) facing one side of the second pole piece (2);

wherein the first pole piece (1) is always separated from the second pole piece (2) in the first local area (31) or the second local area (32).

2. The cell according to claim 1, characterized in that the width of the insulator (4) is equal to the width of the first pole piece (1) or the width of the insulator (4) is equal to the width of the second pole piece (2).

3. A cell according to claim 1, characterized in that at least one end of the insulator (4) extends in the width direction along the end of the first pole piece (1) and is exposed.

4. A cell according to claim 3, characterized in that the exposed width of the insulator (4) is 0.2-2mm.

5. The cell according to any of claims 1-4, characterized in that the membrane (3) has the first partial region (31) and the second partial region (32), and that both the first partial region (31) and the second partial region (32) are provided with the insulator (4).

6. The cell according to any of claims 1-4, wherein the first pole piece (1), the separator (3) and the second pole piece (2) are wound to form a core (5), and the insulator (4) is located in the innermost layer of the core (5).

7. The cell according to claim 6, characterized in that the length of the innermost layer of the core (5) is greater than the length of the insulator (4).

8. The cell according to claim 7, wherein one side of the insulator (4) is in contact with one side of the innermost layer of the core (5) in the length direction, and the other side of the insulator (4) is spaced apart from the other side of the innermost layer of the core (5).

9. The cell according to claim 7, wherein both sides of the insulator (4) are spaced apart from both sides of the innermost layer of the core (5) in the length direction.

10. A cell according to claim 9, characterized in that the spacing between the insulator (4) and the core (5) is 0.5-1.5mm.