CN219457793U - Soft package battery cell and battery module - Google Patents

Abstract

The utility model belongs to the technical field of power batteries, and relates to a soft-package battery cell and a battery module. The soft package battery core comprises a pole piece stacking body, a leading-out part and an aluminum plastic film; the first end of the leading-out part is connected with the pole piece stacking body; the aluminum plastic film comprises an edge sealing area and a cladding area, the edge sealing area is located at the edge of the side part of the cladding area, the cladding area covers the first end of the leading-out part and the pole piece stacking body, the second end of the leading-out part extends out of the edge sealing area and is located outside the cladding area, the edge sealing area seals to form a top seal for packaging the first end of the leading-out part and the pole piece stacking body in the cladding area, at least part of the top seal is in an arc-shaped structure, and an opening of the arc-shaped structure faces the pole piece stacking body. The beneficial effects include: the edge sealing area of the aluminum plastic film forms a top seal with an outwards convex arc-shaped structure during packaging, so that stress concentration caused by gas production in the soft package battery core to the top seal is reduced, the phenomenon that the top seal is broken from the inside due to the stress concentration is avoided, the sealing reliability of the top seal is improved, and the service lives of the soft package battery core and the battery module are prolonged.

Description

Soft package battery cell and battery module

Technical Field

The utility model belongs to the technical field of power batteries, and particularly relates to a soft-package battery cell and a battery module.

Background

The lithium ion battery has the advantages of high energy density, good safety, light volume and the like, and is widely applied to 3C digital electronics, hand-held electric tools, energy storage equipment, new energy automobiles and the like. The structure of the current lithium ion battery mainly comprises a soft package battery, a hard shell battery and a cylindrical battery, wherein the soft package battery has high energy density and wide application prospect. The soft package battery core of the soft package battery is generally formed by packaging a pole piece stacking body by two aluminum plastic films punched with pits, and simultaneously packaging the lead-out part into the seal structure. The soft package battery core adopts a three-edge sealing or four-edge sealing structure, the seal of the package lead-out part is generally called top sealing, and the long-term reliability of the seal structure is the guarantee of the full life cycle safety use of the soft package battery core.

As shown in fig. 1, the top seals 301 adopted at present are linear type bar seals, the soft package battery core can generate gas in the long-term use process, the pressure inside the soft package battery core is gradually increased, a stress concentration area 50 can be formed at the top seals 301, after the gas generation amount reaches a certain degree, the top seals 301 can be broken through from the inside due to stress concentration, so that the performance of the soft package battery core is reduced, even liquid leakage is caused, and the reliability of the soft package battery core and the battery module is affected.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present utility model is to provide a soft battery cell and a battery module for reducing stress concentration caused by gas generation of the soft battery cell to the top seal, so as to improve reliability of the soft battery cell and the battery module.

To achieve the above and other related objects, the present utility model provides a soft package battery cell, comprising:

a pole piece stack;

a lead-out portion, a first end of which is electrically connected with the pole piece stack; and

the aluminum plastic film comprises an edge sealing area and a cladding area, wherein the edge sealing area is positioned at the edge of the side part of the cladding area, the cladding area covers the first end of the leading-out part and the pole piece stacking body, the second end of the leading-out part extends out of the edge sealing area and is positioned outside the cladding area, the edge sealing area seals to form a top seal which encapsulates the first end of the leading-out part and the pole piece stacking body in the cladding area, at least part of the top seal is in an arc-shaped structure, and the opening of the arc-shaped structure faces the pole piece stacking body.

Optionally, in the first direction, the length of top seal is greater than the width of drawing forth portion, the top seal include with draw forth portion overlap first encapsulation section and with draw forth portion staggered second encapsulation section, first encapsulation section with the second encapsulation section is arc structure.

Optionally, the second packaging sections are distributed at two ends of the first packaging section and are connected with the first packaging section to form a continuous and smooth arc-shaped structure.

Optionally, in the first direction, the length of the top seal is greater than the width of the leading-out portion, the top seal includes a first encapsulation section overlapped with the leading-out portion and a second encapsulation section staggered with the leading-out portion, one of the first encapsulation section and the second encapsulation section is in an arc structure, and the other of the first encapsulation section and the second encapsulation section is in a single-section linear structure or in a multi-section linear connected fold line structure.

Optionally, the radian of the arc-shaped structure is R, and R is more than 0 and less than or equal to pi.

Optionally, the first end of the extraction part and the pole piece stacking body are arranged between the two layers of the aluminum plastic films, the edge sealing area comprises a first edge sealing section overlapped with the extraction part and a second edge sealing section staggered with the extraction part, the two layers of the second edge sealing sections are overlapped and bonded or fused in a hot pressing mode to form the second packaging section, and the two layers of the first edge sealing sections are in sealing connection with the extraction part to form the first packaging section.

Optionally, the lead-out part is provided with tab glue, and the first edge sealing section is in sealing connection with the lead-out part through the tab glue.

Optionally, two lead-out parts are arranged at the same end of the pole piece stacking body.

Optionally, the two ends of the pole piece stacking body are respectively provided with the extraction parts.

To achieve the above and other related objects, the present utility model also provides a battery module, including the soft package battery cell as described above.

As described above, the soft package battery cell and the battery module have at least the following beneficial effects: the first end of the lead-out part and the pole piece stacking body are packaged through the aluminum plastic film, and the edge sealing area of the aluminum plastic film forms a top seal with an arc-shaped structure when in packaging, the arc-shaped structure is bent towards the direction back to the pole piece stacking body, so that the stress concentration caused by gas production in the soft package battery core to the top seal is reduced, the top seal is prevented from being broken from the inside due to the stress concentration, the sealing reliability of the top seal is improved, and the service life of the soft package battery core and the battery module is prolonged.

Drawings

Fig. 1 is a schematic structural diagram of a prior art soft-pack cell;

fig. 2 is a schematic structural diagram of a first embodiment of a soft package battery cell according to the present utility model;

fig. 3 is a schematic structural diagram of a second embodiment of a soft package battery cell according to the present utility model;

fig. 4 is a schematic structural diagram of a third embodiment of a soft package battery cell according to the present utility model;

fig. 5 is a schematic structural diagram of a fourth embodiment of a soft package battery cell according to the present utility model;

description of the part reference numerals

The pole piece stack body 10, the lead-out part 20, the aluminum plastic film 30, the top seal 301, the first packaging section 3011, the second packaging section 3012, the edge sealing area 302, the cladding area 303, the tab glue 40 and the stress concentration area 50.

Detailed Description

Further advantages and effects of the present utility model will become apparent to those skilled in the art from the disclosure of the present utility model, which is described by the following specific examples.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the utility model to the extent that it can be practiced, since modifications, changes in the proportions, or otherwise, used in the practice of the utility model, are not intended to be critical to the essential characteristics of the utility model, but are intended to fall within the spirit and scope of the utility model. Also, the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like recited in the present specification are merely for descriptive purposes and are not intended to limit the scope of the utility model, but are intended to provide relative positional changes or modifications without materially altering the technical context in which the utility model may be practiced.

Referring to fig. 2-5, in some alternative embodiments, the present application provides a battery module including a soft pack cell.

Referring to fig. 2-5, in some alternative embodiments, the pouch cell includes a pole piece stack 10, an extraction 20, and an aluminum plastic film 30. Wherein a first end of the lead-out portion 20 is electrically connected to the pole piece stack 10; the aluminum plastic film 30 comprises an edge sealing area 302 and a cladding area 303, the edge sealing area 302 is located at the side edge of the cladding area 303, the cladding area 303 covers the first end of the lead-out portion 20 and the pole piece stack 10, the second end of the lead-out portion 20 extends out of the edge sealing area 302 and is located outside the cladding area 303, namely, one part of the lead-out portion 20 is located in the cladding area 303, and the other part of the lead-out portion 20 is located outside the cladding area 303. The edge sealing region 302 forms a top seal 301 sealing the first end of the lead-out portion 20 and the pole piece stack 10 in the cladding region 303, at least part of the top seal 301 is configured as an arc-shaped structure, and the opening of the arc-shaped structure is bent towards the pole piece stack 10, i.e. the arc-shaped structure is bent towards the direction facing away from the pole piece stack 10.

Optionally, two lead-out portions 20 are provided at the same end of the pole piece stack 10, and the edge sealing region 302 is located at one side edge of the cladding region 303. Alternatively, the two ends of the pole piece stacking body 10 are respectively provided with the lead-out parts 20, and the edge sealing areas 302 are positioned at the two side edges of the cladding area 303; further, the edge seal areas 302 are located at opposite side edges of the wrapping area 303. The electrode plate stack 10 may be formed by sequentially stacking an anode plate, a diaphragm and a cathode plate, the lead-out portion 20 may be a conductive metal plate, the lead-out portion 20 may be electrically connected with the electrode plate stack 10 by a welding manner, and the electrode plate stack 10 is electrically connected with the outside through the lead-out portion 20, so that current of the electrode plate stack 10 may be led out of the soft package battery core, thereby realizing charging and discharging of the soft package battery core.

Optionally, the first end of the lead-out portion 20 is connected to the end of the pole piece stack 10, the arc-shaped structure is located between the second end of the lead-out portion 20 and the end of the pole piece stack 10 and is curved in a direction facing away from the end of the pole piece stack 10, i.e. the arc-shaped structure protrudes towards the second end of the lead-out portion 20, and the inner arc of the arc-shaped structure faces the pole piece stack 10. Further, both the side of the arc-shaped structure facing the end of the pole piece stack 10 and the side facing away from the end of the pole piece stack 10 are convex in the direction facing away from the end of the pole piece stack 10, i.e. both the inner side and the outer side of the arc-shaped structure are curved in the direction facing away from the end of the pole piece stack 10. Because the stress concentration areas 50 in the soft package battery core are mainly distributed at the two ends of the pole piece stacking body 10, the soft package battery core can generate gas in the pole piece stacking body 10 in the long-term use process, the pressure intensity in the soft package battery core is gradually increased, when the gas quantity reaches a certain degree, the top seal 301 can be broken through from the inside due to stress concentration, the seal of the top seal 301 is designed into an arc-shaped structure, and the arc-shaped structure is bent in the direction opposite to the end part of the pole piece stacking body 10, so that the stress concentration caused by the gas generation of the pole piece stacking body 10 on the top seal 301 can be effectively reduced, the leakage risk is reduced, and the performance and the service cycle of the soft package battery core are improved.

In the soft package battery core in the above embodiment, the gas generated in the soft package battery core forms the stress concentration area 50, and the top seal 301 at least partially adopts the convex arc structure, so that the influence of the local stress concentration on the encapsulation effect of the top seal 301 can be effectively reduced, and the long-term reliability of encapsulation is improved.

Referring to fig. 2, in some alternative embodiments, in the first direction, the length of the top seal 301 is greater than the width of the lead-out portion 20, specifically, the length of the top seal 301 is D1, and the width of the lead-out portion 20 is D2, i.e., D1 is greater than D2. The top seal 301 includes a first seal segment 3011 overlapping the lead-out portion 20 and a second seal segment 3012 offset from the lead-out portion 20, and the first seal segment 3011 and the second seal segment 3012 are each arc-shaped. In the present application, the first direction, the width direction of the pole piece stack body 10, and the width direction of the lead-out portion 20 are the same, that is, the Y direction in the drawing; the length direction of the pole piece stack 10 is the same as the length direction of the lead-out portion 20, i.e., the X direction in the drawing.

Optionally, the second packaging sections 3012 are distributed at two ends of the first packaging section 3011, and the second packaging section 3012 is connected with the first packaging section 3011 to form a continuous smooth arc structure, that is, no abrupt points exist between the second packaging section 3012 and the first packaging section 3011. Further, the second package segments 3012 are symmetrically distributed on both sides of the first package segment 3011 along the first direction.

The soft package battery core of the embodiment has continuous and smooth arc structure and wide application range, and effectively reduces the influence of stress concentration on the top seal 301.

Referring to fig. 3-5, in some alternative embodiments, in the first direction, the length of the top seal 301 is greater than the width of the lead-out portion 20, specifically, the length of the top seal 301 is D1, and the width of the lead-out portion 20 is D2, i.e., D1 is greater than D2. The top seal 301 includes a first sealing section 3011 overlapping the lead-out portion 20 and a second sealing section 3012 offset from the lead-out portion 20, one of the first sealing section 3011 and the second sealing section 3012 has an arc-shaped structure, and the other of the first sealing section 3011 and the second sealing section 3012 has a single-section straight line structure or a multi-section straight line connected fold line structure, wherein the multi-section straight line includes two or more straight lines.

Optionally, the second encapsulation sections 3012 are distributed on both sides of the first encapsulation section 3011 along the first direction, and are connected to the first encapsulation section 3011.

Alternatively, referring to fig. 3, the first packaging section 3011 has an arc structure, and the second packaging section 3012 has a fold line structure formed by connecting two sections in a straight line.

Alternatively, referring to fig. 4, the first packaging section 3011 has a fold line structure formed by connecting three sections in a straight line, and the second packaging section 3012 has an arc structure.

Alternatively, referring to fig. 5, the first encapsulation section 3011 is a single-section straight line structure, and the second encapsulation section 3012 is an arc-shaped structure.

It will be appreciated that the arcuate configuration of the top seal 301 is not limited to the above-described exemplary embodiment, for example, the arcuate configuration may also be formed by a portion of the first package section 3011, or by a portion of the second package section 3012, or by portions of the first package section 3011 being connected to portions of the second package section 3012 to form a continuous arcuate configuration.

In the soft package battery core of the above embodiment, a part of the top seal 301 is in an arc structure, and a part of the top seal 301 is in a single-segment linear structure or a broken line structure, so that the influence of stress concentration on the top seal 301 can be reduced, and the packaging difficulty can be reduced.

Referring to FIGS. 2-5, in some embodiments, the arc of the arcuate structure may be R, and 0 < R+.pi..

Alternatively, the arc R may be any of pi/6, pi/5, 2pi/5, pi/2, or pi.

The soft package battery core of the above embodiment, the arc structure adopts a proper radian, so that the influence of stress concentration on the top seal 301 can be further reduced, and the reliability of the top seal 301 is improved.

Referring to fig. 2-5, in some embodiments, the first end of the lead 20 and the pole piece stack 10 are disposed between two layers of plastic-aluminum film 30, and the edge sealing area 302 includes a first edge sealing section overlapping the lead 20 and a second edge sealing section staggered from the lead 20, where the two layers of second edge sealing sections overlap and are adhesively secured or heat-pressed to form a second encapsulation section 3012, and where the two layers of first edge sealing sections are sealed with the lead 20 to form a first encapsulation section 3011.

Optionally, the lead-out portion 20 is provided with a tab adhesive 40, and the first edge sealing section is connected with the lead-out portion 20 in a sealing manner through the tab adhesive 40. Further, the first edge sealing section is adhered and sealed to the lead-out portion 20 by the tab adhesive 40.

Alternatively, the two aluminum plastic films 30 may be two independent square aluminum plastic films 30 formed into a two-layer structure, the two aluminum plastic films 30 are oppositely arranged, the pole piece stack body 10 is located between the two aluminum plastic films 30, the first end of the lead-out portion 20 extends into the space between the two aluminum plastic films 30 to be electrically connected with the pole piece stack body 10, four sides of the aluminum plastic films 30 are packaged, and the top seal 301 is located at one side or two sides corresponding to the lead-out portion 20; or the two layers of aluminum plastic films 30 can be a square aluminum plastic film 30 folded into a two-layer structure, the pole piece stacking body 10 is positioned between the two layers of aluminum plastic films 30, the first end of the lead-out part 20 stretches into the space between the two layers of aluminum plastic films 30 and is electrically connected with the pole piece stacking body 10, the three sides of the aluminum plastic films 30 are packaged, and the top seal 301 is positioned on one side or two sides corresponding to the lead-out part 20.

The soft package battery core of the embodiment has the advantages of simple structure, convenient assembly and encapsulation operation and reliable encapsulation of the aluminum plastic film 30, and can ensure that the first end of the lead-out part 20 and the pole piece stacking body 10 are reliably encapsulated in the aluminum plastic film 30 for a long time, thereby ensuring the performance of the soft package battery core.

According to the soft-package battery cell and the battery module, the top seal 301 is at least partially constructed into the arc-shaped structure, so that the stress concentration of the stress concentration region 50 can be effectively reduced, the influence of the stress concentration on the package is reduced, the long-term reliability of the package is improved, the leakage risk is reduced, and the service lives of the soft-package battery cell and the battery module are prolonged.

In the description of the present specification, the descriptions of the terms "present embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above embodiments are merely illustrative of the principles of the present utility model and its effectiveness, and are not intended to limit the utility model. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the utility model. Accordingly, it is intended that all equivalent modifications and variations of the utility model be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (10)

1. A soft pack cell, comprising:

a pole piece stack;

a lead-out portion, a first end of which is electrically connected with the pole piece stack; and

the aluminum plastic film comprises an edge sealing area and a cladding area, wherein the edge sealing area is positioned at the edge of the side part of the cladding area, the cladding area covers the first end of the leading-out part and the pole piece stacking body, the second end of the leading-out part extends out of the edge sealing area and is positioned outside the cladding area, the edge sealing area seals to form a top seal which encapsulates the first end of the leading-out part and the pole piece stacking body in the cladding area, at least part of the top seal is in an arc-shaped structure, and the opening of the arc-shaped structure faces the pole piece stacking body.

2. The soft pack cell of claim 1, wherein: in the first direction, the length of top seal is greater than the width of drawing forth the portion, the top seal include with draw forth the portion overlap first encapsulation section and with draw forth the second encapsulation section that the portion staggers, first encapsulation section with the second encapsulation section is arc structure.

3. The soft pack cell of claim 2, wherein: the second packaging sections are distributed at two ends of the first packaging section and are connected with the first packaging section to form a continuous smooth arc-shaped structure.

4. The soft pack cell of claim 1, wherein: in the first direction, the length of the top seal is greater than the width of the leading-out part, the top seal comprises a first packaging section overlapped with the leading-out part and a second packaging section staggered with the leading-out part, one of the first packaging section and the second packaging section is of an arc-shaped structure, and the other of the first packaging section and the second packaging section is of a single-section straight line structure or a broken line structure with multiple sections of straight lines connected.

5. The soft pack cell of claim 3 or 4, wherein: the radian of the arc-shaped structure is R, and R is more than 0 and less than or equal to pi.

6. The soft pack cell of claim 2 or 4, wherein: the first end of the leading-out part and the pole piece stacking body are arranged between the two layers of the aluminum plastic films, the edge sealing area comprises a first edge sealing section overlapped with the leading-out part and a second edge sealing section staggered with the leading-out part, the two layers of the second edge sealing sections are overlapped and bonded or fused in a hot pressing mode to form the second packaging section, and the two layers of the first edge sealing sections are in sealing connection with the leading-out part to form the first packaging section.

7. The soft pack cell of claim 6, wherein: and the leading-out part is provided with tab glue, and the first edge sealing section is in sealing connection with the leading-out part through the tab glue.

8. The soft pack cell of any one of claims 1 to 4, wherein: the same end of the pole piece stacking body is provided with two leading-out parts.

9. The soft pack cell of any one of claims 1 to 4, wherein: and the two ends of the pole piece stacking body are respectively provided with the leading-out parts.

10. A battery module, characterized in that: a soft pack cell comprising any one of claims 1 to 9.