WO2023240904A1

WO2023240904A1 - Battery cell sealed by grooving and sealing process, and battery module

Info

Publication number: WO2023240904A1
Application number: PCT/CN2022/129988
Authority: WO
Inventors: 肖天丽; 陈敏; 李尚益; 黄利明
Original assignee: 湖北亿纬动力有限公司
Priority date: 2022-06-17
Filing date: 2022-11-04
Publication date: 2023-12-21
Also published as: CN217788479U

Abstract

The present application discloses a battery cell sealed by a grooving and sealing process, and a battery module. A cover plate of the battery cell sealed by a grooving and sealing process is snap-fitted to the opening of a housing; the cover plate comprises a fixing portion, a first protruded portion, and a recessed portion; a sealing ring is provided between the housing and the cover plate; an annular limiting slot is formed in the lower end surface of the fixing portion; an annular protrusion is provided on the sealing ring; the annular protrusion is clamped in the annular limiting slot.

Description

Roll groove sealed cells and battery modules

This application claims priority from the Chinese patent application with the filing date of June 17, 2022 and the application number 202221525016.0. The entire content of this application is incorporated into this application by reference.

Technical field

The present application relates to the field of battery technology, for example, to a roll groove sealed battery cell and a battery module.

Background technique

Lithium-ion batteries are widely used in the 3C field and the field of power tools due to their advantages of high specific energy, long cycle life, good safety, light weight, no memory effect and no pollution. With the continuous development of lithium-ion battery technology, higher requirements have been placed on the quality and service life of lithium-ion batteries.

In related technologies, the cells of some lithium-ion batteries are often sealed by rolling groove sealing. However, during the long-term use of the cells, the electrolyte inside the cells will expand with the increase of use time, which is prone to occur. If the cover assembly protrudes outward, it is easy to cause a short circuit and have low safety performance. Moreover, due to the force-bearing characteristics of the cover assembly that adopts roll groove sealing, the edge of the cover assembly, that is, the position close to the shell, is subject to compressive stress. Larger, the compressive stress on the center of the cover assembly is lower. When sealing, the edges of the cover assembly will collapse seriously, which may easily cause poor sealing, leakage, and shorten the service life of the battery.

Contents of the invention

This application provides a cell and battery module with a roll groove seal. The cover plate is not easy to bulge and deform outwards, has sufficient sealing strength, is not prone to leakage, has a long service life, and has good safety performance.

In a first aspect, an embodiment of the present application provides a roll groove sealed battery core. The roll groove sealed battery core includes:

A shell with an opening at one end;

The cover plate is fastened at the opening and connected to the housing through a rolling groove seal. The cover plate includes a fixed part, a first protruding part and a recessed part that are connected to each other. The lower end surface of the fixed part is provided with an annular limiting groove; and

Sealing ring, the sealing ring is arranged between the housing and the fixed part, and the sealing ring is provided with an annular protrusion at a position corresponding to the annular limiting groove, and the annular protrusion is clamped on inside the annular limiting groove.

In one embodiment, the first protruding part is annular, and the first protruding part is provided with a circular notch.

In one embodiment, the first protruding portion is annular, and the first protruding portion is provided with a C-shaped notch and a connecting portion, and the C-shaped notch and the connecting portion form a circle.

In one embodiment, the central angle corresponding to the connecting portion is 5° to 20°.

In one embodiment, the recessed portion is provided with a second protruding portion, the second protruding portion is annular, and the highest point of the second protruding portion is lower than the highest point of the first protruding portion. point.

In one embodiment, the depth of the annular limiting groove is smaller than the height of the annular protrusion.

In one embodiment, the height difference between the annular limiting groove and the annular protrusion is 0.2 mm to 0.6 mm.

In one embodiment, the diameter of the cover plate is 38 mm to 45 mm, and the thickness of the cover plate is 0.3 mm to 2.0 mm.

In one embodiment, the thickness of the sealing ring is 0.5 mm to 1.5 mm.

On the other hand, the present application provides a battery module, including the roll-groove sealed battery core in any of the above solutions, and a plurality of the roll-groove sealed battery cores are provided.

The beneficial effects of this application are:

The present application provides a roll groove sealed battery core. The roll groove sealed battery core includes a shell, a cover plate and a sealing ring. One end of the shell has an opening, the cover plate is fastened at the opening, and the cover plate includes interconnected The fixed part, the first convex part and the recessed part, the first convex part and the recessed part can absorb the minor deformation of the cover plate and avoid the short circuit or poor connection caused by the surface of the cover plate protruding from the opening edge of the housing. , the sealing ring is arranged between the shell and the cover plate. When the shell and the cover plate are fixed by rolling groove sealing, the sealing ring is pressed between the shell and the cover plate, and the lower end surface of the fixed part is provided with an annular Limit groove, the sealing ring is provided with an annular protrusion, and the annular protrusion is clamped in the annular limit groove. Through the setting of the annular limit groove and annular protrusion, the seal ring and the cover plate are prevented from being displaced during sealing. phenomenon to ensure accurate positioning between the cover plate, sealing ring and casing, reliable sealing, and less prone to leakage.

The present application also provides a battery module, which includes the above-mentioned roll-groove sealed battery cells. There are a plurality of roll-grooved sealed battery cells. The cover plates of the roll-grooved sealed battery cells of the battery module are evenly stressed and are not easily deformation occurs, and the sealing is reliable, not easy to leak, and has good safety performance.

Description of the drawings

Figure 1 is a schematic structural diagram of a roll groove sealed battery core provided in Embodiment 1 of the present application;

Figure 2 is a partial enlarged view of point A in Figure 1;

Figure 3 is a partial enlarged view of B in Figure 1;

Figure 4 is a top view of the cover plate provided in Embodiment 1 of the present application;

Figure 5 is a top view of the cover plate provided in Embodiment 2 of the present application.

In the picture:

100. Shell; 200. Cover plate; 210. Fixed part; 2101. Annular limiting groove; 220. First protruding part; 2201. Circular notch; 2202. C-shaped notch; 2203. Connection part; 230 , recessed portion; 240, second protruding portion; 300, sealing ring; 310, annular protrusion.

Detailed ways

In the description of this application, unless otherwise explicitly stipulated and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body. ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood on a case-by-case basis.

In this application, unless otherwise explicitly stated and limited, the term "above" or "below" a first feature on a second feature may include direct contact between the first and second features, or may also include the first and second features. Not in direct contact but through additional characteristic contact between them. Furthermore, the terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above and diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this embodiment, the terms "upper", "lower", "left", "right" and other orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplified operation. It is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and have no special meaning.

Embodiment 1

As shown in Figures 1 to 3, this embodiment provides a roll groove sealed battery core. The roll groove sealed battery core includes a housing 100, a cover plate 200 and a sealing ring 300. One end of the housing 100 has an opening. The cover 200 is fastened to the opening of the casing 100 and is connected to the casing 100 through rolling groove sealing. The cover 200 includes a fixed part 210, a first protruding part 220 and a recessed part 230 that are connected to each other, wherein, The fixing part 210 and the first protruding part 220 are annular, the recessed part 230 is circular, the inner ring of the first protruding part 220 is connected to the outer edge of the recessed part 230, and the inner ring of the fixing part 210 is connected to the first protruding part 220. The outer ring of the fixing part 210 is connected to the housing 100. Due to the characteristics of the rolling groove sealing process, the compressive stress on the outer edge of the cover plate 200 is greater than the compressive stress on the center position. Through the first protrusion The arrangement of the first protruding portion 220 and the recessed portion 230 can improve the ability of the cover plate 200 to resist compressive stress and ensure good sealing performance. At the same time, the first protruding portion 220 and the recessed portion 230 can absorb minor deformations of the cover plate 200 and prevent the cover plate 200 from being deformed. The surface protrudes from the edge of the opening of the housing 100, resulting in a short circuit or poor connection. The sealing ring 300 is provided between the housing 100 and the fixed part 210. The lower end surface of the fixed part 210 is provided with an annular limiting groove 2101 to seal. The ring 300 is provided with an annular protrusion 310 at a position corresponding to the annular limit groove 2101. The annular protrusion 310 is clamped in the annular limit groove 2101. The annular protrusion 310 can be used as a sealing compression point between the housing 100 and the cover plate 200. It plays a position limiting role during sealing to prevent the position of the sealing ring 300 and the cover plate 200 from shifting, ensuring accurate positioning, uniform circumferential stress on the cover plate 200, and maintaining the upper and lower stress points of the cover plate 200 Consistent, reliable sealing, avoiding liquid leakage, and good safety performance.

In one embodiment, the depth of the annular limiting groove 2101 is smaller than the height of the annular protrusion 310, so that the sealing compression point of the sealing ring 300 can be pressed against the cover plate 200 to ensure the reliability of the sealing. For example, the height difference between the annular limiting groove 2101 and the annular protrusion 310 is 0.2 mm to 0.6 mm. In some embodiments, the height difference between the annular limiting groove 2101 and the annular protrusion 310 may be set to 0.2mm, 0.3mm, 0.4mm, 0.5mm or 0.6mm. In other embodiments, the height difference between the annular limiting groove 2101 and the annular protrusion 310 can also be other values within this range, which is not limited in this embodiment.

Referring to FIG. 4 , the first protruding portion 220 of the roll-grooved battery core in this embodiment is provided with a circular notch 2201 . When the battery core sealed by the roll groove undergoes thermal runaway and the gas, liquid, etc. inside the casing 100 expands rapidly, the circular notch 2201 breaks to release the pressure inside the casing 100 and control the trend of heat spread. The circular notch 2201 serves as a pressure relief structure for the roll groove sealed battery core, which can avoid the risk of explosion of the roll groove sealed battery core.

For example, in this embodiment, the diameter of the cover plate 200 is 38 mm ~ 45 mm, the thickness of the cover plate 200 is 0.3 mm ~ 2.0 mm, the thickness of the sealing ring 300 is 0.5 mm ~ 1.5 mm, and the diameter of the circular notch 2201 is It is 20mm~30mm. The specific value can be determined according to the actual situation and will not be repeated here.

In one embodiment, continuing to refer to FIGS. 1 and 4 , the recessed portion 230 is provided with a second protruding portion 240 , the second protruding portion 240 is annular, and the highest point of the second protruding portion 240 is lower than the first protruding portion. The highest point of the origin is 220. By providing the first protruding portion 220 , the second protruding portion 240 and the recessed portion 230 , a concave-convex structure is formed on the cover plate 200 , thereby absorbing slight deformation of the cover plate 200 without affecting the directional pressure relief of the battery core. normal use, while improving the ability of the cover plate 200 to resist compressive stress to ensure good sealing performance.

This embodiment also provides a battery module, including the above-mentioned roll groove sealed battery core. There are multiple roll groove sealed battery cores. Due to the annular protrusion 310 on the sealing ring 300 and the fixed part 210 of the cover 200, The setting of the annular limit groove 2101 makes the cover plate 200 evenly stressed and difficult to deform, and the sealing is reliable and difficult to leak. At the same time, due to the setting of the circular notch 2201, it can ensure that when thermal runaway occurs, the housing The gas and liquid inside the 100 can completely erupt, and the effect of controlling heat spread is good and the safety performance is high.

Embodiment 2

This embodiment provides a roll groove sealed battery core. As shown in Figure 5, the difference between the roll groove sealed battery core in the second embodiment and the roll groove sealed battery core in the first embodiment is that: the roll groove sealed battery core in this embodiment The first protruding portion 220 of the core is provided with a C-shaped notch 2202 and a connecting portion 2203, and the C-shaped notch 2202 and the connecting portion 2203 form a circle. When the battery core sealed by the roll groove undergoes thermal runaway and the gas, liquid, etc. inside the casing 100 expands rapidly, the C-shaped notch 2202 breaks and flips around the connection part 2203, thereby releasing the pressure inside the casing 100 and controlling the The trend of heat spreading. At this time, the C-shaped notch 2202 serves as a pressure relief structure for the roll groove sealed battery core, which can avoid the risk of explosion of the roll groove sealed battery core. At the same time, due to the setting of the connecting portion 2203, a pressure relief structure can be realized. directional opening, and the cover 200 will not fly out after the pressure relief structure is opened, ensuring the safety of users.

In one embodiment, the diameter of the circle is 20 mm to 30 mm. The specific value can be determined according to the actual situation, and will not be described again here.

Continuing to refer to Figure 5, in this embodiment, the central angle α corresponding to the connecting part 2203 is 5°-20°, thereby ensuring that the connecting part 2203 has sufficient connection strength. After the C-shaped notch 2202 is broken, the connecting part 2203 will not break. break, thereby ensuring that the inside of the C-shaped notch 2202 of the cover 200 will not fly out after being flipped over, thereby ensuring the safety of users. For example, the central angle α corresponding to the connecting portion 2203 is 5°, 10°, 15° or 20°, which can be specifically selected according to the thickness of the cover plate 200, which is not limited in this embodiment. Of course, in other embodiments, the central angle α corresponding to the connecting portion 2203 can also be selected to have other values within this range, which will not be described again here.

This embodiment also provides a battery module, including the above-mentioned roll groove sealed battery cores. There are multiple roll groove sealed battery cores, and the connecting portions 2203 of the multiple roll groove sealed battery cores are arranged on the same side, so that in When thermal runaway occurs, the pressure relief structures of multiple roll-grooved sealed cells can be opened in the same direction, ensuring that the roll-grooved sealed cells erupt in a directional manner when they catch fire, thus releasing the pressure inside the casing 100, thus achieving high safety performance. And due to the arrangement of the connecting portion 2203, the pressure relief structure will not fly out after opening. In addition, due to the annular protrusion 310 on the sealing ring 300 and the annular limiting groove 2101 on the fixed part 210, the cover plate 200 is evenly stressed, is not prone to deformation, has reliable sealing, is not prone to leakage, and has good safety performance. .

The remaining structures of the roll-grooved sealed battery core in this embodiment are the same as those in Embodiment 1, and will not be described again here.

Claims

A roll groove sealed battery core, including:

Housing (100), one end of the housing (100) has an opening;

Cover plate (200), the cover plate (200) is buckled at the opening and connected to the casing (100) through rolling groove sealing. The cover plate (200) includes fixed fixing parts connected to each other. (210), the first protruding portion (220) and the recessed portion (230), the lower end surface of the fixed portion (210) is provided with an annular limiting groove (2101); and

Sealing ring (300), the sealing ring (300) is disposed between the housing (100) and the fixed part (210), and the sealing ring (300) corresponds to the annular limiting groove ( An annular protrusion (310) is provided at the position 2101), and the annular protrusion (310) is clamped in the annular limiting groove (2101).
The roll groove sealed battery core according to claim 1, wherein the first protruding part (220) is annular, and the first protruding part (220) is provided with a circular notch (2201).
The roll groove sealed battery core according to claim 1, wherein the first protruding part (220) is annular, and the first protruding part (220) is provided with a C-shaped notch (2202) and The connecting part (2203), the C-shaped notch (2202) and the connecting part (2203) form a circle.
The roll groove sealed battery core according to claim 3, wherein the central angle α corresponding to the connecting portion (2203) is 5° to 20°.
The roll groove sealed battery core according to claim 1, wherein the recessed part (230) is provided with a second protruding part (240), the second protruding part (240) is annular, and the The highest point of the second protruding part (240) is lower than the highest point of the first protruding part (220).
The roll groove sealed battery core according to any one of claims 1 to 5, wherein the depth of the annular limiting groove (2101) is less than the height of the annular protrusion (310).
The roll groove sealed battery core according to claim 6, wherein the height difference between the annular limiting groove (2101) and the annular protrusion (310) is 0.2 mm to 0.6 mm.
The roll groove sealed battery core according to any one of claims 1 to 5, wherein the diameter of the cover plate (200) is 38mm～45mm, and the thickness of the cover plate (200) is 0.3mm～ 2.0mm.
The roll groove sealed battery core according to any one of claims 1 to 5, wherein the thickness of the sealing ring (300) is 0.5 mm to 1.5 mm.
A battery module includes the roll-groove sealed battery core according to any one of claims 1 to 9, and a plurality of the roll-groove sealed battery cores are provided.