CN220065875U - Soft package battery - Google Patents

Abstract

The utility model provides a soft package battery, which comprises a film body, a battery cell and a metal sealing piece, wherein the film body is provided with an accommodating cavity, the battery cell is arranged in the accommodating cavity, the film body comprises a first film body and a second film body, the first film body is covered on the second film body along a first direction and is connected with the second film body in a hot melting way, the metal sealing piece is arranged on at least one side edge of the film body along a second direction, the metal sealing piece extends along the second direction, the metal sealing piece is arranged on the outer side of the edge of the film body in a surrounding way, and the metal sealing piece is connected with the film body; the first direction is along the thickness direction of the battery cell, and the second direction is along one of the length direction or the width direction of the battery cell. The soft package battery has good sealing performance.

Description

Soft package battery

Technical Field

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

Background

The liquid lithium battery can be divided into a soft-package battery and a hard-shell battery according to the shell, the soft-package battery generally adopts an aluminum-plastic film as an outer package material, and the aluminum-plastic film is a multi-layer composite film, so that the liquid lithium battery has the properties of high barrier property, good formability, electrolyte corrosion resistance and the like, and is widely applied to the field of soft-package lithium ion batteries at present.

The aluminum plastic film comprises an outer protective layer, a middle aluminum layer and an inner heat sealing layer, and in the production and assembly process of the soft package battery, the battery is packaged by heat, namely, the aluminum plastic film is pressurized by a hot pressing die, the heat sealing layers of the aluminum plastic film are melted in a certain time, and the heat sealing layers are mutually adhered and solidified after cooling, so that the purpose of packaging the battery is achieved.

However, the electrolyte may infiltrate along with the hot melt gap, thereby causing leakage of the electrolyte.

Disclosure of Invention

Based on the above, the utility model provides a soft package battery, which solves the defects of the related art by arranging a metal sealing member outside the edge of a film body.

The utility model provides a soft package battery, which comprises a film body, a battery cell and a metal sealing piece, wherein the film body is provided with an accommodating cavity, the battery cell is arranged in the accommodating cavity, the film body comprises a first film body and a second film body, the first film body is covered on the second film body along a first direction and is connected with the second film body in a hot melting way, the metal sealing piece is arranged on at least one side edge of the film body along a second direction, the metal sealing piece extends along the second direction, the metal sealing piece is arranged on the outer side of the edge of the film body in a surrounding way, and the metal sealing piece is connected with the film body;

the first direction is along the thickness direction of the battery cell, and the second direction is along one of the length direction or the width direction of the battery cell.

In one possible implementation, the soft package battery provided by the utility model, the metal sealing member is an aluminum sealing member.

In one possible implementation, the soft package battery provided by the utility model is provided with a metal sealing member welded with a film body.

In one possible implementation manner, the metal sealing member of the soft package battery provided by the utility model comprises a sealing member body and two sealing parts, wherein the cross sections of the sealing member body and the sealing parts are rectangular, the two sealing parts are respectively connected to two opposite ends of the sealing member body, one of the two sealing parts is connected with the first film body, and the other sealing part is connected with the second film body.

In one possible implementation manner, the soft package battery provided by the utility model is characterized in that an adhesive layer is arranged between one surface of the sealing part facing the film body and one surface of the film body facing the sealing part;

and/or the end part of the sealing part, which is away from the sealing part body, is welded with the film body.

In one possible implementation manner, the length of the sealing part along the first direction of the soft package battery is greater than or equal to the thickness of the film body and less than or equal to 2 times the thickness of the film body.

In a possible implementation manner, in the soft package battery provided by the utility model, the edge of the film body is provided with the hot melt connection region, and the extension length of the sealing part along the third direction is greater than or equal to one half of the extension length of the hot melt connection region along the third direction and less than or equal to the extension length of the hot melt connection region along the third direction;

wherein, the first direction and the second direction are perpendicular to the third direction.

In one possible implementation manner, the soft package battery provided by the utility model has the extension length of the metal sealing member along the second direction larger than the extension length of the hot melt connection area along the second direction.

In one possible implementation manner, the length difference between the metal sealing member and the hot-melt connection region along the second direction of the soft package battery is greater than or equal to 2mm and less than or equal to 10mm.

In one possible implementation manner, the soft package battery provided by the utility model further comprises a tab, wherein the sealing element body is provided with an avoidance groove, and the tab is connected to the battery core and extends out of the accommodating cavity through the avoidance groove.

The utility model provides a soft package battery, which comprises a film body, an electric core and a metal sealing piece, wherein the film body comprises a first film body and a second film body which are mutually connected in a hot melting way, the electric core and electrolyte are packaged by arranging the first film body and the second film body, the electric core is used for generating current, the metal sealing piece is arranged on the outer side of the edge of the film body in a surrounding way, so that the edge part of the film body is fully wrapped, and the edge of the film body is sealed, so that the electrolyte is prevented from leaking and diffusing through a hot melting gap at the side edge of the film body. Therefore, the soft package battery has good sealing performance.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the present utility model, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a soft package battery according to an embodiment of the present utility model;

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a cross-sectional view taken along A-A of FIG. 2;

fig. 4 is a partial enlarged view at B in fig. 3.

Reference numerals illustrate:

100-film body; 110-a first film body; 120-a second film body; 130-a hot melt connection zone;

200-cell;

300-metal seal; 310-a seal body; 320-sealing part;

400-an adhesive layer;

500-pole lugs.

Detailed Description

In order to make the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions in the preferred embodiments of the present utility model will be described in more detail with reference to the accompanying drawings in the preferred embodiments of the present utility model. In the drawings, the same or similar reference numerals refer to the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of the utility model. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model. Embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

In the description of the present utility model, it should be noted that, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, indirectly connected through an intermediary, or may be in communication with each other between two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present utility model, it should be understood that the terms "upper," "lower," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship of the drawings, merely to facilitate description of the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

The terms first, second, third and the like in the description and in the claims and in the above-described figures, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented, for example, in sequences other than those illustrated or otherwise described herein.

Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or display that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or display.

The liquid lithium battery can be divided into a soft-package battery and a hard-shell battery according to the shell, the soft-package battery generally adopts an aluminum-plastic film as an outer package material, and the aluminum-plastic film is a multi-layer composite film, so that the liquid lithium battery has the properties of high barrier property, good formability, electrolyte corrosion resistance and the like, and is widely applied to the field of soft-package lithium ion batteries at present.

The aluminum plastic film comprises an outer protective layer, a middle aluminum layer and an inner heat sealing layer, and in the production and assembly process of the soft package battery, the battery is packaged by heat, namely, the aluminum plastic film is pressurized by a hot pressing die, the heat sealing layers of the aluminum plastic film are melted in a certain time, and the heat sealing layers are mutually adhered and solidified after cooling, so that the purpose of packaging the battery is achieved.

However, the electrolyte may infiltrate along with the hot melt gap, thereby causing leakage of the electrolyte. The heat sealing layer of the aluminum plastic film is made of high polymer materials, the high polymer materials cannot be completely sealed in hot melting connection, some hot melting gaps are inevitably generated, electrolyte can diffuse among the high polymer materials, and the hot melting gaps are larger and larger along with the increase of the service time of the soft package battery.

In view of the above problems, the embodiments of the present utility model provide a soft package battery, in which a metal seal is disposed on the outer side of the edge of a film body, so as to further seal a hot-melt connection region of the film body, thereby preventing the electrolyte from leaking and diffusing from the hot-melt gap.

Referring to fig. 1 to 3, the present utility model provides a flexible battery, the flexible battery includes a film body 100, a battery cell 200 and a metal seal 300, the film body 100 has a receiving cavity, the battery cell 200 is disposed in the receiving cavity, the film body 100 includes a first film body 110 and a second film body 120, the first film body 110 is covered on the second film body 120 along a first direction and is in thermal fusion connection with each other, the metal seal 300 is disposed on at least one side of the film body 100 along a second direction, the metal seal 300 extends along the second direction, the metal seal 300 is disposed around the outer side of the edge of the film body 100, and the metal seal 300 is connected with the film body 100.

Wherein the first direction is along the thickness direction of the battery cell 200, and the second direction is along one of the length direction or the width direction of the battery cell 200.

In the present utility model, the film body 100 is used for packaging the battery cell 200 and the electrolyte, specifically, the film body 100 may include a first film body 110 and a second film body 120, a pit is punched on the whole film body 100, the pit is used for placing the battery cell 200, then the film body 100 is folded in half, so that a half film body 100 with the pit, i.e. the first film body 110, and a flat half film body 100, i.e. the second film body 120, can be formed, and the second film body 120 is covered on the first film body 110 along the thickness direction of the battery cell 200, and after the two film bodies are mutually and thermally fused, a square accommodating cavity for accommodating the battery cell 200 and the electrolyte is formed in the film body 100, and four sides, i.e. two sides along the length direction of the film body 100 and two sides along the width direction of the film body 100, are formed at the edge of the film body 100.

For example, the film body 100 may be an aluminum plastic film.

The battery cell 200 may include a positive electrode sheet, a negative electrode sheet, and a separator, and the battery cell 200 is used to react with an electrolyte, thereby generating a current by charge and discharge.

The metal seal 300 is used to further seal the side edges of the membrane body 100 after the first and second membrane bodies 110 and 120 are thermally fused to prevent leakage of the electrolyte.

Specifically, the metal sealing member 300 is disposed around the outer side of the edge of the film body 100 to fully wrap the edge of the film body 100, it is understood that the projection of the film body 100 in the first direction is located in the projection of the metal sealing member 300 in the first direction, and the metal sealing member 300 is connected with the first film body 110 and the second film body 120 to seal the hot-melt connection portion of the first film body 110 and the second film body 120, so as to prevent the electrolyte from leaking from the hot-melt connection portion of the first film body 110 and the second film body 120.

When the second direction indicates the longitudinal direction of the battery cell 200, the metal seal 300 is disposed on one or both sides of the longitudinal direction of the film body 100, and the metal seal 300 extends along the longitudinal direction of the film body 100, and the metal seal 300 is used to seal the heat-sealing slit in the longitudinal direction of the film body 100.

When the second direction indicates the width direction of the battery cell 200, the metal seal 300 is disposed at one or both sides of the width direction of the film body 100, and the metal seal 300 extends along the width direction of the film body 100, and the metal seal 300 is used to seal the thermal fusion gap of the width direction of the film body 100.

The first direction may refer to the X direction in fig. 4, and the second direction may refer to the Y direction in fig. 2.

It should be understood that, in packaging the soft package battery, it is necessary to perform hot-melt packaging on three sides of the film body 100, and only one side is left for injecting the electrolyte, so that the three sides have the phenomenon of electrolyte permeation leakage after performing hot-melt packaging, and thus the three sides may be provided with the metal seal 300 to improve the sealing performance of the film body 100.

In the related art, by extending the path of the hot-melt packaging, the leakage and diffusion phenomena of the electrolyte are not improved from the root cause, and after the hot-melt connection, the heat sealing layer of the aluminum plastic film still generates the hot-melt gap due to the material defect, but the soft package battery of the present utility model starts from the leakage path of the film body 100, and seals the side edge of the film body 100 by arranging the metal sealing member 300 outside the edge of the film body 100, so as to prevent the electrolyte from leaking from the hot-melt gap of the side edge of the film body 100. And the metal seal 300 is made of a metal material, the electrolyte is not easily diffused through the metal material, compared with the polymer material.

The flexible package battery provided by the embodiment of the utility model comprises a film body 100, a battery cell 200 and a metal sealing member 300, wherein the film body 100 comprises a first film body 110 and a second film body 120 which are mutually connected in a hot melting way, the battery cell 200 and electrolyte are packaged by arranging the first film body 110 and the second film body 120, the battery cell 200 is used for generating current, and the metal sealing member 300 is arranged on the outer side of the edge of the film body 100 so as to comprehensively wrap the side edge of the film body 100 and further seal the side edge of the film body 100, thereby preventing the electrolyte from leaking and diffusing through a hot melting gap at the side edge of the film body 100. Therefore, the soft package battery has good sealing performance.

In one possible implementation, the metal seal 300 is an aluminum seal.

It can be appreciated that the middle layer of the aluminum plastic film is aluminum foil, and aluminum is adopted as the material of the metal sealing member 300, and the material of the middle layer of the aluminum plastic film is the same as that of the middle layer of the aluminum plastic film, so that the aluminum plastic film can be better connected with the aluminum plastic film, and the connection stability of the aluminum sealing member and the film body 100 is better.

The metal seal 300 may be a sheet metal part or an extruded part, that is, formed by stamping an aluminum plate or by extrusion of an aluminum material.

As an alternative embodiment, the metal seal 300 is welded to the membrane body 100.

The metal sealing member 300 is connected with the film body 100 by welding, so that the connection part between the metal sealing member 300 and the first film body 110 and the connection part between the metal sealing member 300 and the second film body 120 are completely sealed, so as to improve the sealing performance of the metal sealing member 300, and the connection between the metal sealing member 300 and the film body 100 is tighter and has higher connection strength.

For example, the metal seal 300 may be welded to the membrane body 100 by laser continuous welding or laser pulse welding.

Referring to fig. 2 to 4, in one possible implementation, the metal seal 300 includes a seal body 310 and two seal portions 320, each of the seal body 310 and the seal portion 320 having a rectangular cross-sectional shape, the two seal portions 320 being respectively connected to opposite ends of the seal body 310, one of the two seal portions 320 being connected to the first film body 110, and the other being connected to the second film body 120.

When the metal seal 300 is cut in the second direction, the cross-sectional shapes of the seal body 310 and the seal portion 320 are rectangular, the length direction of the rectangular cross-section of the seal body 310 is in the first direction, the width direction of the rectangular cross-section of the seal body 310 is in the third direction, the length direction of the rectangular cross-section of the seal portion 320 is in the third direction, and the width direction of the rectangular cross-section of the seal portion 320 is in the first direction.

In this manner, the metal seal 300 may be connected to the first and second film bodies 110 and 120 by providing two sealing parts 320 to wrap the side edges of the first film body 110 through the seal body 310 and one sealing part 320, and include the side edges of the second film body 120 through the seal body 310 and the other sealing part 320, so that the seal body 310 and the two sealing parts 320 may entirely wrap the side edges of the film body 100 to seal the heat-fusible cut of the film body 100.

With continued reference to fig. 2-4, in one possible implementation, an adhesive layer 400 is provided between the side of the sealing portion 320 facing the membrane body 100 and the side of the membrane body 100 facing the sealing portion 320. And/or the end of the seal 320 facing away from the seal body 310 is welded to the membrane body 100.

It is understood that the adhesive layer 400 may be disposed between the surface of the sealing portion 320 facing the membrane body 100 and the surface of the membrane body 100 facing the sealing portion 320, and the end of the sealing portion 320 facing away from the sealing member body 310 is welded to the membrane body 100.

An adhesive layer 400 may be provided between a surface of the sealing portion 320 facing the film body 100 and a surface of the film body 100 facing the sealing portion 320, or an end of the sealing portion 320 facing away from the seal body 310 may be welded to the film body 100.

An adhesive layer 400 is disposed between the surface of the sealing portion 320 connected with the first film body 110 facing the first film body 110 and the surface of the sealing portion 320 facing the first film body 110, and an adhesive layer 400 is also disposed between the surface of the sealing portion 320 connected with the second film body 120 facing the second film body 120 and the surface of the sealing portion 320 facing the second film body 120, and by disposing the adhesive layer 400 between the film body 100 and the sealing portion 320, the sealing portion 320 is preliminarily fixed by the adhesive layer 400, so that the metal seal 300 can be prevented from slipping when the subsequent sealing portion 320 is welded with the film body 100.

The end of the sealing part 320 connected with the first film body 110, which is away from the sealing member body 310, is welded with the first film body 110, and the end of the sealing part 320 connected with the second film body 120, which is away from the sealing member body 310, is welded with the second film body 120, so that both the sealing parts 320 are welded with the first film body 110 and the second film body 120, and therefore, both the sealing parts 320 and the first film body 110 and the sealing parts 320 and the second film body 120 are in sealing connection, and the metal sealing member 300 can fully wrap the side edges of the film body 100.

As an alternative embodiment, the extension length of the sealing part 320 in the first direction is greater than or equal to the thickness of the film body 100 and less than or equal to 2 times the thickness of the film body 100.

It is understood that the metal seal 300 may be an aluminum plate with equal thickness, that is, the thickness of the seal body 310 is consistent with the thickness of the seal portion 320, and the extension length of the seal portion 320 along the first direction is the thickness of the seal portion 320, and the thicknesses of the first film body 110 and the second film body 120 are consistent.

If the thickness of the sealing portion 320 is too large, the welding structure between the sealing portion 320 and the first film body 110 is unstable, or the welding structure between the sealing portion 320 and the second film body 120 is unstable, and at the same time, the thickness of the sealing portion 320 is too large, which also excessively increases the volume of the soft battery, thereby reducing the energy density of the soft battery.

If the thickness of the sealing portion 320 is too small, the sealing portion 320 is easily pierced, so that the sealing portion 320 cannot completely wrap the first film body 110 or the second film body 120, and the sealing portion 320 is too small and is easily pierced when the sealing portion 320 is welded to the film body 100.

Therefore, it is a reasonable range to set the thickness of the sealing part 320 to be greater than or equal to the thickness of the film body 100, and to set the thickness of the sealing part 320 to be less than or equal to 2 times the thickness of the film body 100, without making the sealing part 320 too thin, causing the sealing part 320 to pierce or weld through, without making the sealing part 320 too thick, causing the welding of the sealing part 320 and the film body 100 to be unstable, and reducing the energy density of the pouch battery.

The thickness of the film body 100 is 80um-120um, and the thickness of the sealing portion 320 may be set to any value between 80um-240um, so as to meet the above requirements.

In one possible implementation manner, the edge of the film body 100 is provided with the hot-melt connection region 130, and the extension length of the sealing portion 320 along the third direction is greater than or equal to one half of the extension length of the hot-melt connection region 130 along the third direction, and less than or equal to the extension length of the hot-melt connection region 130 along the third direction.

The first direction and the second direction are perpendicular to the third direction, and the third direction can refer to the Z direction in fig. 3 and 4.

It should be understood that when the second direction indicates the length direction of the battery cell 200, the third direction indicates the width direction of the battery cell 200, and conversely, when the second direction indicates the width direction of the battery cell 200, the third direction indicates the length direction of the battery cell 200.

After the heat sealing layers at the edges of the first film body 110 and the second film body 120 are in hot-melt connection, a hot-melt connection region 130 is formed, the length direction of the hot-melt connection region 130 is along the second direction, and the width direction of the hot-melt connection region 130 is along the third direction. The three side edges of the film body 100 may be provided with the hot melt connection regions 130.

The longitudinal direction of the sealing portion 320 coincides with the longitudinal direction of the thermal fusion joining region 130, and the width direction of the sealing portion 320 coincides with the width direction of the thermal fusion joining region 130.

If the width of the sealing part 320 is too narrow, the sealing effect of the sealing part 320 is poor, and if the width of the sealing part 320 is too wide, the volume of the pouch battery is excessively increased, and thus the energy density of the pouch battery is reduced. In order for the sealing part 320 to effectively seal the hot-melt connection region 130 and secure the energy density of the pouch cell, the width of the sealing part 320 should be not less than one-half of the width of the hot-melt connection region 130 and not more than the width of the hot-melt connection region 130.

As an alternative embodiment, the metal seal 300 has an extension in the second direction that is greater than the extension of the hot melt connection region 130 in the second direction.

That is, both ends of the metal seal 300 should exceed both ends of the hot melt connection region 130, so that both ends of the metal seal 300 are subjected to a closing-up process to secure tightness of the metal seal 300. Therefore, the extension length of the metal seal 300 along the second direction should be greater than the extension length of the hot melt connection region 130 along the second direction, so that the extension length of the metal seal 300 along the second direction is free to facilitate the closing-in of both ends of the metal seal 300.

In one possible implementation, the length difference between the metal seal 300 and the hot melt connection region 130 in the second direction is greater than or equal to 2mm and less than or equal to 10mm.

If the length difference between the metal seal 300 and the hot-melt connection region 130 along the second direction is too small, the two ends of the metal seal 300 are inconvenient to close, the tightness of the metal seal 300 cannot be ensured, and if the length difference between the metal seal 300 and the hot-melt connection region 130 along the second direction is too large, the use of the soft-pack battery can be affected.

Accordingly, it is a preferable range that both ends of the metal seal 300 in the second direction respectively exceed both ends of the thermal fusion joining zone 130 by 1mm to 5 mm.

Referring to fig. 1 to 4, in a possible implementation manner, the soft package battery provided by the embodiment of the present utility model further includes a tab 500, where the seal member body 310 is provided with an avoidance groove, and the tab 500 is connected to the battery cell 200 and extends out of the accommodating cavity through the avoidance groove.

Thus, when the metal seal 300 is disposed at the edge of one side of the tab 500, the tab 500 may extend out of the accommodating cavity through the avoiding groove, so that the tab 500 is connected with the battery cell 200 and the device to be powered, and the current of the battery cell 200 is led out.

In addition, a protective layer may be provided on the surface of the metal seal 300 to protect the metal seal 300 from oxidation of the metal seal 300.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model.

Claims (10)

1. The battery is characterized by comprising a film body, an electric core and a metal sealing piece, wherein the film body is provided with an accommodating cavity, the electric core is arranged in the accommodating cavity, the film body comprises a first film body and a second film body, the first film body is covered on the second film body along a first direction and is connected with the second film body in a hot melting way, the metal sealing piece is arranged on at least one side edge of the film body along a second direction, the metal sealing piece extends along the second direction, the metal sealing piece is arranged on the outer side of the edge of the film body in a surrounding mode, and the metal sealing piece is connected with the film body;

wherein the first direction is along a thickness direction of the battery cell, and the second direction is along one of a length direction or a width direction of the battery cell.

2. The pouch cell of claim 1, wherein the metal seal is an aluminum seal.

3. The pouch cell of claim 1, wherein the metal seal is welded to the membrane.

4. A pouch cell according to any of claims 1 to 3, wherein the metal seal comprises a seal body and two seal portions, each of which has a rectangular cross-sectional shape, the two seal portions being connected to opposite ends of the seal body, respectively, one of the two seal portions being connected to the first film body and the other one being connected to the second film body.

5. The flexible battery according to claim 4, wherein an adhesive layer is provided between a surface of the sealing portion facing the film body and a surface of the film body facing the sealing portion;

and/or the end part of the sealing part, which is away from the sealing piece body, is welded with the film body.

6. The pouch cell of claim 4, wherein the sealing portion has an extension in the first direction that is greater than or equal to the thickness of the film body and less than or equal to 2 times the thickness of the film body.

7. The flexible battery according to claim 4, wherein the edge of the film body is provided with a hot-melt connection region, and the extension length of the sealing part along the third direction is greater than or equal to one half of the extension length of the hot-melt connection region along the third direction and less than or equal to the extension length of the hot-melt connection region along the third direction;

wherein the first direction and the second direction are perpendicular to the third direction.

8. The pouch cell of claim 7, wherein the metal seal has an extension in the second direction that is greater than an extension of the hot melt connection region in the second direction.

9. The pouch cell of claim 8, wherein the metal seal and the hot melt connection region have a length in the second direction that is greater than or equal to 2mm and less than or equal to 10mm.

10. The battery pack of claim 4, further comprising a tab, wherein the seal body is provided with a relief groove, and wherein the tab is connected to the cell and extends out of the receiving cavity through the relief groove.