CN117977130B - Battery Cells and Battery Packs - Google Patents

Abstract

The present invention relates to the field of battery technology, and discloses a battery cell and a battery pack, wherein the battery cell comprises: a shell; an insulating film, which is coated on the outside of the shell; the insulating film is provided with a plurality of windows, the windows are provided corresponding to the side of the shell, the length of the side of the shell is L, and along the length direction of the side of the shell, the length of the area occupied by the plurality of windows is a, which satisfies 0.4≤a/L≤0.8. The present invention improves the bonding strength between the battery cell shell and the battery pack when bonding the battery cell by providing windows on the insulating film, thereby improving the life and safety of the battery pack; by controlling the length of the area occupied by the plurality of windows, it is ensured that the insulation effect of the battery cell is not affected while the bonding strength is improved.

Description

Battery Cells and Battery Packs

Technical Field

The present invention relates to the technical field of batteries, and in particular to battery cells and battery packs.

Background technique

The battery generally includes an internal structure and an external structure. The external structure mainly includes a cell cover, a cell shell and a cell insulating component. The insulating component on the cell shell can prevent the metal shell from short-circuiting with the outside, play an insulating role, and also play a protective role to prevent the cell shell from being worn or scratched.

However, when the battery cell and the battery pack are bonded together, the connection strength between the battery cell and the battery pack is reduced due to the influence of the insulating components, which affects the life and safety of the battery pack.

Summary of the invention

In view of this, the present invention provides a battery cell and a battery pack to solve the problem that the insulating component affects the connection strength between the battery cell and the battery pack.

In a first aspect, the present invention provides a battery cell, comprising: a shell; an insulating film, coated on the outside of the shell; the insulating film is provided with a plurality of windows, the windows are arranged corresponding to the side surfaces of the shell, the length of the side surface of the shell is L, and along the length direction of the side surface of the shell, the length of the area occupied by the plurality of windows is a, satisfying 0.4≤a/L≤0.8.

Beneficial effects: By opening windows in the insulating film, the bonding strength between the battery cell shell and the battery pack is improved when bonding the battery cells, thereby improving the life and safety of the battery pack; by controlling the length of the area occupied by multiple windows, it is ensured that the insulation effect of the battery cell is not affected while improving the bonding strength.

In an optional embodiment, along the length direction of the side surface of the shell, the plurality of windows are located in the middle area of the side surface of the shell; or, along the length direction of the side surface of the shell, the plurality of windows are located on one side of the side surface of the shell; or, the plurality of windows are respectively located on both sides of the side surface of the shell, and along the length direction of the side surface of the shell, the length of the area occupied by the windows on one side of the side surface of the shell is a1, and the length of the area occupied by the windows on the other side of the side surface of the shell is a2, satisfying a=a1+a2; or, the plurality of windows are evenly distributed on the side surface of the shell.

In an optional embodiment, multiple windows are located in the middle area of the side of the shell, and the length a of the area occupied by the multiple windows is 200mm to 1000mm; multiple windows are located on one side of the side of the shell, and the length a of the area occupied by the multiple windows is 200mm to 1000mm, and along the length direction of the side of the shell, the distance b from the edge of the area occupied by the multiple windows to the nearest edge of the side of the shell is 5mm to 20mm; multiple windows are respectively located on both sides of the side of the shell, the length a1 of the area occupied by the windows located on one side of the shell side is 50mm to 250mm, and the length a2 of the area occupied by the windows located on the other side of the shell side is 50mm to 250mm, along the length direction of the side of the shell, the distance b1 from the edge of the window occupied area located on one side of the shell side to the nearest edge of the side of the shell is 5mm to 20mm, and the distance b2 from the edge of the window occupied area located on the other side of the shell side to the nearest edge of the side of the shell is 5mm to 20mm.

In an optional embodiment, the center distance m between two adjacent windows is 10 mm to 30 mm.

In an optional embodiment, the window is circular, elliptical or polygonal.

In an optional embodiment, the window is circular, and the window radius R is 2 mm to 10 mm; the window is rectangular, and the window width is 8 mm to 46 mm, and the window length is 5 mm to 20 mm.

Beneficial effect: The window opening radius has a suitable size, which can not only increase the window opening area and improve the bonding strength between the battery cell shell and the battery pack, but also ensure the insulation effect of the battery cell.

In an optional embodiment, the window is circular, and along the width direction of the side of the shell, the distance from the edge of the window to the edge of the side of the shell is n, satisfying that n is greater than 1 mm; the window is rectangular, and along the width direction of the side of the shell, the distance from the edge of the window to the edge of the side of the shell is n, satisfying that n is greater than 2 mm.

In an optional implementation, the length Z of the shell is 200 mm to 1200 mm, the width X of the shell is 50 mm to 200 mm, and the thickness Y of the shell is 12 mm to 50 mm.

In an optional implementation, the thickness h of the insulating film is 50 μm to 200 μm.

Beneficial effect: By controlling the thickness of the insulating film, the strength requirement of the insulating film fitting the shell surface can be met.

In a second aspect, the present invention further provides a battery pack, comprising the above-mentioned battery cell.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of an exploded structure of a battery cell according to an embodiment of the present invention;

FIG2 is a schematic diagram of a structure in which a plurality of windows are located in the middle of a side surface of a housing according to an embodiment of the present invention;

FIG3 is a partial enlarged schematic diagram of A in FIG2 ;

FIG4 is a schematic diagram of the overall structure of a battery cell according to an embodiment of the present invention;

FIG5 is a schematic structural diagram of a plurality of windows located on one side of a side surface of a housing according to an embodiment of the present invention;

FIG6 is a schematic structural diagram of a plurality of windows located on both sides of a side surface of a housing according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a plurality of windows evenly distributed on the side of a housing according to an embodiment of the present invention.

Description of reference numerals:

10. Shell; 20. Insulating film; 21. Window; 30. Pole group; 40. Top cover; 50. Patch.

Detailed ways

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

The embodiments of the present invention are described below in conjunction with FIG. 1 to FIG. 7 .

According to an embodiment of the present invention, on the one hand, a battery cell is provided, comprising: a shell 10 and an insulating film 20, wherein the insulating film 20 is coated on the outer side of the shell 10. The insulating film 20 is provided with a plurality of windows 21, and the windows 21 are arranged corresponding to the side of the shell 10, the length of the side of the shell 10 is L, and the length of the area occupied by the plurality of windows 21 along the length direction of the side of the shell 10 is a, satisfying 0.4≤a/L≤0.8.

By using the battery cell of this embodiment, by opening windows 21 in the insulating film 20, the bonding strength between the battery cell housing 10 and the battery pack is improved when the battery cell is bonded, thereby improving the life and safety of the battery pack; by controlling the length of the area occupied by the multiple windows 21, it is ensured that the insulation effect of the battery cell is not affected while the bonding strength is improved.

It should be noted that the area occupied by the multiple windows 21 includes the portion between two adjacent windows 21 .

It should be noted that, in this embodiment, the battery cells are bonded using structural adhesive.

It should be noted that the insulating film 20 is mostly a smooth surface, which makes the adhesion between the structural adhesive and the insulating film 20 lower, thereby reducing the bonding strength between adjacent cells. Therefore, by providing the window 21, the housing 10 is in direct contact with the structural adhesive at the position of the window 21, thereby increasing the bonding strength.

Specifically, the battery cell in this embodiment is a blade battery cell.

Of course, in other alternative embodiments, the battery cell may also be a square shell battery cell, and the window is arranged at the bottom or other sides of the square shell battery cell.

It is worth noting that by providing a plurality of windows 21 , the bonding strength between the cell housing 10 and the battery pack is further improved while satisfying the insulation effect of the cell.

In one embodiment, as shown in Figure 2, along the length direction of the side of the shell 10, multiple windows 21 are located in the middle area of the side of the shell 10; or, along the length direction of the side of the shell 10, multiple windows 21 are located on one side of the side of the shell 10; or, multiple windows 21 are respectively located on both sides of the side of the shell 10, and along the length direction of the side of the shell 10, the length of the area occupied by the windows 21 on one side of the side of the shell 10 is a1, and the length of the area occupied by the windows 21 on the other side of the side of the shell 10 is a2, satisfying a=a1+a2; or, multiple windows 21 are evenly distributed on the side of the shell 10.

In this embodiment, as shown in FIG. 2 , a plurality of windows 21 are located in the middle area of the side surface of the housing 10 .

It is worth noting that the structural adhesive is generally applied in the middle of the battery cell, with less adhesive applied at the two ends. Therefore, setting multiple windows 21 in the middle area of the side of the shell 10 is more conducive to improving the bonding strength between the battery cell shell 10 and the battery pack.

Of course, referring to FIG. 5 , in another embodiment, a plurality of windows 21 are located on one side of the side surface of the housing 10 .

Of course, please refer to Figure 6. In another embodiment, multiple windows 21 are respectively located on both sides of the side of the shell 10. Along the length direction of the side of the shell 10, the length of the area occupied by the window 21 on one side of the side of the shell 10 is a1, and the length of the area occupied by the window 21 on the other side of the side of the shell 10 is a2, satisfying a=a1+a2.

Of course, referring to FIG. 7 , in other alternative embodiments, the plurality of windows 21 are evenly distributed on the side surface of the housing 10 .

In one embodiment, as shown in FIG. 2 , the plurality of windows 21 are located in a middle area of a side surface of the housing 10 , and the length a of the area occupied by the plurality of windows 21 is 200 mm to 1000 mm.

Specifically, in this embodiment, the length a of the area occupied by the multiple windows 21 is 250 mm, and along the length direction of the side of the shell 10, the distance from the edge of the area occupied by the multiple windows 21 to the edge of the side of the shell 10 is 125 mm.

It should be noted that, along the length direction of the side surface of the shell 10 , the distance from the edge of the area occupied by the multiple windows 21 to the edge of the side surface of the shell 10 is also the length of the area without the windows 21 .

Of course, please refer to Figure 5, in another embodiment, the multiple windows 21 are located on one side of the side of the shell 10, the length a of the area occupied by the multiple windows 21 is 200mm to 1000mm, and along the length direction of the side of the shell 10, the distance b from the edge of the area occupied by the multiple windows 21 to the edge of the nearest side of the shell 10 is 5mm to 20mm.

Of course, please refer to Figure 6. In another embodiment, multiple windows 21 are respectively located on both sides of the side of the shell 10, and the length a1 of the area occupied by the window 21 on one side of the side of the shell 10 is 50mm to 250mm, and the length a2 of the area occupied by the window 21 on the other side of the side of the shell 10 is 50mm to 250mm. Along the length direction of the side of the shell 10, the distance b1 from the edge of the area occupied by the window 21 on one side of the side of the shell 10 to the edge of the nearest side of the shell 10 is 5mm to 20mm, and the distance b2 from the edge of the area occupied by the window 21 on the other side of the side of the shell 10 to the edge of the nearest side of the shell 10 is 5mm to 20mm.

In one embodiment, as shown in FIG. 3 , the center distance m between two adjacent windows 21 is 10 mm to 30 mm.

Specifically, in this embodiment, the center distance m between two adjacent windows 21 is 20 mm.

It is worth noting that if the value of m is too small, that is, the distance between two adjacent windows 21 is too close, the remaining insulating film 20 between the two adjacent windows 21 is too small, and it is difficult to ensure the connection strength between the insulating film 20 and the shell 10; if the value of m is too large, that is, the distance between two adjacent windows 21 is too far, the bonding strength between the battery cells or between the battery cells and other components cannot be guaranteed.

In one embodiment, as shown in FIG. 1 and FIG. 2 , the window 21 is circular, and the radius R of the window 21 is 2 mm to 10 mm.

Specifically, in this embodiment, the radius R of the window 21 is 4 mm.

Of course, in another embodiment, the window 21 is rectangular, the width of the window 21 is 8 mm to 46 mm, and the length of the window 21 is 5 mm to 20 mm.

Of course, in other alternative embodiments, the window 21 may also be in other shapes, such as other polygons, ellipses, etc.

It is worth noting that when the area of the window 21 is too large, the bonding strength between the battery cell and the battery pack is improved, but at this time, the insulation performance of the insulating film 20 is unqualified due to the large area of the window 21; when the area of the window 21 is too small, although the insulation performance of the insulating film 20 is still within the range, the bonding strength between the battery cell and the battery pack is not fully improved. Therefore, making the radius of the window 21 have a suitable size can not only increase the area of the window 21, improve the bonding strength between the battery cell and the battery pack, but also ensure the insulation effect of the battery cell.

In one embodiment, as shown in FIG. 3 , the window 21 is circular, and along the width direction of the side surface of the shell 10 , the distance from the edge of the window 21 to the edge of the side surface of the shell 10 is n, and n satisfies that n is greater than 1 mm.

Specifically, in this embodiment, the distance n from the edge of the window 21 to the edge of the side surface of the housing 10 is 3.5 mm.

It should be noted that along the width direction of the side of the shell 10, the multiple windows 21 are located in the middle position of the side of the shell 10, that is, the distance from the upper edge of the window 21 to the upper edge of the side of the shell 10 is equal to the distance from the lower edge of the window 21 to the lower edge of the side of the shell 10.

Of course, in another embodiment, the window 21 is rectangular, and along the width direction of the side of the shell 10, the distance from the edge of the window 21 to the edge of the side of the shell 10 is n, and n satisfies that n is greater than 2 mm.

It is worth noting that if the value of n is too small, that is, the distance from the edge of the window 21 to the edge of the side of the shell 10 is too close, the remaining insulating film 20 between the edge of the window 21 and the edge of the side of the shell 10 is too small, and it is difficult to ensure the connection strength between the insulating film 20 and the shell 10; if the value of n is too large, that is, the distance from the edge of the window 21 to the edge of the side of the shell 10 is too far, the bonding strength between the battery cells or between the battery cells and other components cannot be guaranteed.

In one embodiment, as shown in FIG. 4 , the length Z of the housing 10 is 200 mm to 1200 mm, the width X of the housing 10 is 50 mm to 200 mm, and the thickness Y of the housing 10 is 12 mm to 50 mm.

Specifically, in this embodiment, the length Z of the housing 10 is 500 mm, the width X of the housing 10 is 120 mm, and the thickness Y of the housing 10 is 15 mm.

It should be noted that, in this embodiment, the small surface of the battery cell (i.e., the Y-Z surface in FIG. 4 ) is bonded to other battery cells by structural adhesive, and the window 21 is opened corresponding to the small surface of the battery cell.

It should be further explained that a window 21 may be opened on other side surfaces (e.g., the X-Z surface in FIG. 4 ) to further improve the bonding strength between the battery cell and the battery pack.

It should be noted that, in the present embodiment, the length L of the side surface of the housing 10 is equal to the length Z of the housing 10 , that is, the length L of the side surface of the housing 10 is also 500 mm.

It should be noted that, in this embodiment, the thickness of the housing 10 is Y=2×R+2×n.

In one embodiment, the thickness h of the insulating film 20 is 50 μm to 200 μm.

Specifically, in this embodiment, the thickness h of the insulating film 20 is 110 μm.

It is worth noting that the thickness of the insulating film 20 is controlled to meet the strength requirement of the insulating film 20 adhering to the surface of the housing 10 .

In one embodiment, as shown in FIG. 1 , the battery cell further includes a pole group 30, a top cover 40 and a patch 50. Two top covers 40 are provided. The two top covers 40 are respectively provided on both sides of the shell 10 and are enclosed with the shell 10 to form a receiving cavity. The pole group 30 is provided in the receiving cavity, and the patch 50 is provided on the surface of the top cover 40 to play an insulating role.

The shear bonding strength test is performed on the battery cells with different window opening 21 sizes. The specific test results are shown in Tables 1 to 4.

Table 1 Shear bond strength test results 1.

The dimensions of the battery cells in the comparative examples and embodiments in Table 1 are consistent, which are length×width×thickness=580mm×120mm×16mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 1 are located on one side of the side surface of the housing 10 .

It can be seen from the test results in Table 1 that when a/L is less than 0.4, the bonding strength between the battery cell and the battery pack is less than 8 MPa, which does not meet the requirements; when a/L is greater than 0.4, the bonding strength between the battery cell and the battery pack is greater than 8 MPa, which meets the requirements.

Table 2 Shear and paste strength test results II.

Among them, the dimensions of the battery cells of the comparative examples and embodiments in Table 2 are consistent, which are length×width×thickness=460mm×100mm×15mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 2 are respectively located on both sides of the side surface of the housing 10 .

It can be seen from the test results in Table 2 that when a/L＜0.4, the bonding strength between the battery cell and the battery pack is less than 8Mpa, which does not meet the requirements; when a/L≥0.4, the bonding strength between the battery cell and the battery pack is greater than 8Mpa, which meets the requirements.

Table 3 Shear bond strength test results III.

The dimensions of the battery cells in the comparative examples and embodiments in Table 3 are consistent, which are length×width×thickness=250mm×50mm×14mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 3 are respectively located on both sides of the side surface of the housing 10 .

It can be seen from the test results in Table 3 that when a/L＜0.4, the bonding strength between the battery cell and the battery pack is less than 8Mpa, which does not meet the requirements; when a/L≥0.4, the bonding strength between the battery cell and the battery pack is greater than 8Mpa, which meets the requirements.

Table 4 Shear bond strength test results IV.

Among them, the dimensions of the battery cells of the comparative examples and embodiments in Table 4 are consistent, which are length×width×thickness=1200mm×200mm×50mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 4 are located in the middle area of the side surface of the housing 10 .

It can be seen from the test results in Table 4 that when a/L＜0.4, the bonding strength between the battery cell and the battery pack is less than 8Mpa, which does not meet the requirements; when a/L≥0.4, the bonding strength between the battery cell and the battery pack is greater than 8Mpa, which meets the requirements.

The following is an insulation withstand voltage test for the battery cells with different insulating films 20. Specifically, a metal plate with conductive silicone is used to support the surface of the battery cell, and the surface of the insulating film 20 is pressed by 2500N to 3000N, and maintained for 2s under the power of high voltage 2000V AC, and the leakage current i of the insulating film 20 is tested. The leakage current i of the insulating film 20 should not exceed 30mA. The specific test results are shown in Tables 5 to 8.

Table 5 Insulation withstand voltage test results 1.

Among them, the dimensions of the battery cells of the comparative examples and embodiments in Table 5 are consistent, which are length×width×thickness=580mm×120mm×16mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 5 are located on one side of the side surface of the housing 10 .

It can be seen from the test results in Table 5 that when a/L≤0.8, the leakage current i of the insulating film 20 is less than 30mA, and the insulation withstand voltage performance of the insulating film 20 meets the requirements; when a/L＞0.8, the leakage current i of the insulating film 20 is greater than 30mA, and the insulation withstand voltage performance of the insulating film 20 does not meet the requirements.

Table 6 Insulation withstand voltage test results II.

Among them, the dimensions of the battery cells of the comparative examples and embodiments in Table 6 are consistent, which are length×width×thickness=460mm×100mm×15mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 6 are respectively located on both sides of the side surface of the housing 10 .

It can be seen from the test results in Table 6 that when a/L≤0.8, the leakage current i of the insulating film 20 is less than 30mA, and the insulation withstand voltage performance of the insulating film 20 meets the requirements; when a/L＞0.8, the leakage current i of the insulating film 20 is greater than 30mA, and the insulation withstand voltage performance of the insulating film 20 does not meet the requirements.

Table 7 Insulation withstand voltage test results III.

Among them, the dimensions of the battery cells of the comparative examples and embodiments in Table 7 are consistent, which are length×width×thickness=250mm×50mm×14mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 7 are respectively located on both sides of the side surface of the housing 10 .

It can be seen from the test results in Table 7 that when a/L≤0.8, the leakage current i of the insulating film 20 is less than 30mA, and the insulation withstand voltage performance of the insulating film 20 meets the requirements; when a/L＞0.8, the leakage current i of the insulating film 20 is greater than 30mA, and the insulation withstand voltage performance of the insulating film 20 does not meet the requirements.

Table 8 Insulation withstand voltage test results IV.

Among them, the dimensions of the battery cells of the comparative examples and embodiments in Table 8 are consistent, all of which are length×width×thickness=1200mm×200mm×50mm.

It should be noted that the multiple windows 21 of the battery cells of the comparative examples and embodiments in Table 8 are located in the middle area of the side surface of the housing 10 .

It can be seen from the test results in Table 8 that when a/L≤0.8, the leakage current i of the insulating film 20 is less than 30mA, and the insulation withstand voltage performance of the insulating film 20 meets the requirements; when a/L＞0.8, the leakage current i of the insulating film 20 is greater than 30mA, and the insulation withstand voltage performance of the insulating film 20 does not meet the requirements.

It is worth noting that, in combination with the test results in Tables 1 to 8, when 0.4≤a/L≤0.8, opening a window 21 on the insulating film 20 can improve the bonding strength between the battery cell and the battery pack without affecting the insulating effect of the insulating film 20 .

According to an embodiment of the present invention, on the other hand, a battery pack is provided, comprising the above-mentioned battery cell.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims (6)

1. A battery cell, comprising: case; An insulating film is coated on the outer side of the shell; the insulating film is provided with a plurality of windows, the windows are arranged corresponding to the side of the shell, the length of the side of the shell is L, and the length of the area occupied by the plurality of windows along the length direction of the side of the shell is a, satisfying 0.4≤a/L≤0.8; The window is circular, elliptical or polygonal; When the window is circular, the radius R of the window is 2 mm to 10 mm; when the window is rectangular, the width of the window is 8 mm to 46 mm, and the length of the window is 5 mm to 20 mm; When the window is circular, along the width direction of the side surface of the shell, the distance from the edge of the window to the edge of the side surface of the shell is n, and n is greater than 1 mm; when the window is rectangular, along the width direction of the side surface of the shell, the distance from the edge of the window to the edge of the side surface of the shell is n, and n is greater than 2 mm; The length Z of the shell is 200 mm to 1200 mm, the width X of the shell is 50 mm to 200 mm, and the thickness Y of the shell is 12 mm to 50 mm. 2. The battery cell according to claim 1, characterized in that, along the length direction of the side surface of the shell, the plurality of windows are located in the middle area of the side surface of the shell; or, Along the length direction of the side surface of the shell, the plurality of windows are located on one side of the side surface of the shell; or, The plurality of windows are respectively located on both sides of the side surface of the shell, and along the length direction of the side surface of the shell, the length of the window located on one side of the side surface of the shell in the occupied area is a1, and the length of the window located on the other side of the side surface of the shell in the occupied area is a2, satisfying a=a1+a2; or, The plurality of windows are evenly distributed on the side surface of the shell. 3. The battery cell according to claim 2, characterized in that the plurality of windows are located in the middle area of the side surface of the shell, and the length a of the area occupied by the plurality of windows is 200 mm to 1000 mm; The plurality of windows are located on one side of the side of the shell, the length a of the area occupied by the plurality of windows is 200 mm to 1000 mm, and along the length direction of the side of the shell, the distance b from the edge of the area occupied by the plurality of windows to the edge of the nearest side of the shell is 5 mm to 20 mm; The multiple windows are respectively located on both sides of the side of the shell, the length a1 of the area occupied by the window on one side of the shell side is 50mm to 250mm, the length a2 of the area occupied by the window on the other side of the shell side is 50mm to 250mm, and along the length direction of the side of the shell, the distance b1 from the edge of the window occupied area on one side of the shell side to the nearest edge of the side of the shell is 5mm to 20mm, and the distance b2 from the edge of the window occupied area on the other side of the shell side to the nearest edge of the side of the shell is 5mm to 20mm. 4. The battery cell according to any one of claims 1 to 3, characterized in that a center distance m between two adjacent windows is 10 mm to 30 mm. 5 . The battery cell according to claim 1 , wherein a thickness h of the insulating film is 50 μm to 200 μm. 6. A battery pack, comprising the battery cell according to any one of claims 1 to 5.