Battery packaging film and soft package battery

Abstract

The utility model belongs to the technical field of soft package batteries, and mainly relates to a battery packaging film which comprises two packaging parts which are symmetrically arranged, each packaging part is provided with an assembling cavity for assembling a battery cell, and each packaging part further comprises a sealing part and an extending part arranged on the outer side of the sealing part; the sealing part is located on the outer side of the assembling cavity and used for packaging the two packaging parts together through hot melt adhesive; the extension part is arranged on the outer side of the sealing part and is used for receiving the hot melt adhesive which is calendered during packaging of the sealing part; the extension part comprises a first extension part and a second extension part, and a tab of the battery cell extends to the outer side of the packaging film through the first extension part; in the radial direction of the assembly cavity, the size of the first extension part is smaller than that of the second extension part; through the design of the first extension part and the second extension part, the frame size of the battery packaging film does not exceed the battery main body after secondary edge sealing, and meanwhile, false sealing of the battery packaging film can be avoided; meanwhile, the utility model further designs a soft package battery prepared by utilizing the battery packaging film, and the battery has the characteristics of high flatness and seal integrity.

Description

Technical Field

[0001] This utility model belongs to the field of soft-pack battery technology, specifically relating to a battery packaging film and a soft-pack battery. Background Technology

[0002] Given the high energy density, lightweight design, and excellent safety performance of pouch polymer lithium-ion batteries, they have increasingly become the core power source for many electronic devices. In the field of Bluetooth devices, with the reduction in the diameter of the button cell pouch polymer lithium-ion battery, the battery height has also been optimized accordingly, allowing it to be more tightly integrated into the internal structure of Bluetooth devices, thereby achieving a wider and deeper coverage of application scenarios.

[0003] To ensure the battery packaging film (aluminum-plastic film) maintains appropriate thickness after perforation, those skilled in the art typically reduce the perforation depth. However, this design causes the cut sealing edge of the pouch battery to extend beyond the battery body after secondary encapsulation, resulting in an overall battery thickness exceeding the specified specifications. Conversely, reducing the size of the top sealing border can lead to hot melt adhesive overflow during the top sealing process, potentially resulting in false sealing and insufficient seal thickness.

[0004] Based on this, we will continue to improve existing battery packaging films and soft-pack batteries to address the aforementioned technical deficiencies. Utility Model Content

[0005] One of the objectives of this utility model is to provide a battery packaging film that addresses the shortcomings of existing technologies, ensuring that the frame size does not exceed the battery body after secondary sealing and effectively preventing false sealing.

[0006] To achieve the above technical objectives, this application implements the following technical solution:

[0007] A battery packaging film includes two symmetrically arranged encapsulation portions. Each encapsulation portion has an assembly cavity for assembling a battery cell. The encapsulation portion also includes a sealing portion and an extension portion disposed outside the sealing portion. The sealing portion, located outside the assembly cavity, is used to seal the two encapsulation portions together with hot melt adhesive. The extension portion, located outside the sealing portion, receives the hot melt adhesive calendered during sealing. The extension portion includes a first extension portion and a second extension portion. The battery cell's electrode tab extends to the outside of the packaging film through the first extension portion. Along the radial direction of the assembly cavity, the size of the first extension portion is smaller than the size of the second extension portion. Preferably, the size is a width value in this application.

[0008] The above technical solution produces the following technical effects:

[0009] This application, by providing a first extension and a second extension, allows the battery cell's tabs to extend smoothly to the outside of the packaging film, while simultaneously catching the hot melt adhesive that extends out during the hot melt adhesive sealing process. The first extension is smaller than the second extension, which helps to better control the distribution of the hot melt adhesive during the sealing process, preventing overflow and ensuring the integrity of the seal and the flatness of the battery packaging film. Therefore, the battery packaging film proposed in this application not only effectively avoids false sealing during secondary sealing but also ensures that the sealing edge dimensions meet requirements.

[0010] As a further improvement to the battery packaging film of this utility model, along the radial direction of the assembly cavity, the dimension of the first extension is D1, the dimension of the second extension is D2, the value range of D1 is 0.3mm-0.4mm, and the value range of D2 is 0.6mm-0.7mm.

[0011] As a further improvement to the battery packaging film of this utility model, the first extension is provided with a tab groove, and the tab extends out of the packaging film through the tab groove.

[0012] As a further improvement to the battery packaging film of this utility model, each encapsulation part is provided with two tab grooves, which are symmetrically arranged on both sides of the arc length direction of the first extension part.

[0013] As a further improvement to the battery packaging film of this utility model, the groove edge of the tab groove near the second extension is the first side, the position where the second extension and the first extension are connected is the second side, and the distance between the first side and the second side is D3.

[0014] The value of D3 ranges from 0.2mm to 0.3mm.

[0015] As a further improvement to the battery packaging film of this utility model, it also includes a connecting part for connecting two packaging parts together.

[0016] As a further improvement to the battery packaging film of this utility model, one end of the connecting part is connected to the first extension of a packaging part, and the other end of the connecting part is connected to the first extension of another packaging part.

[0017] As a further improvement to the battery packaging film of this utility model, the two encapsulation parts are designed symmetrically along the length axis of the connecting part.

[0018] As a further improvement to the battery packaging film of this utility model, it also includes an air bag, which is connected to the second extension and has a sealing area.

[0019] The second objective of this invention is to provide a soft-pack battery with high integrity and high flatness, based on the shortcomings of existing technologies.

[0020] To achieve the above objectives, this application implements the following technical solution:

[0021] A pouch battery is manufactured by cutting the battery packaging film shown in any of the above descriptions.

[0022] The above technical solution produces the following technical effects:

[0023] By using the battery packaging film of this invention, the sealing edge size of the soft-pack battery can be precisely controlled after secondary packaging to avoid exceeding the battery body, while ensuring the flatness of the battery packaging film and the integrity of the seal. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0026] Figure 2 This is a side view of embodiment 2 of this utility model;

[0027] Figure 3 for Figure 1 A magnified view of a portion at point A;

[0028] in:

[0029] 1-Packaging section;

[0030] 11-Assembly cavity;

[0031] 12-Seal Department;

[0032] 13-Extension;

[0033] 131 - First extension;

[0034] 1311 - Ear groove;

[0035] 1312 – Second side;

[0036] 132 - Second extension;

[0037] 1321 - First side;

[0038] 2-Connecting part;

[0039] 3-Airbag;

[0040] 31 - Packaging area. Detailed Implementation

[0041] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application.

[0042] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0043] Although this application discloses preferred embodiments as described above, it is not intended to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

[0044] The present invention will be further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0045] Implementation Method 1

[0046] like Figure 1-2As shown, to address the issue of existing battery packaging films having frame sizes exceeding the battery body and resulting in false sealing due to shrinkage caused by perforation, this application improves the structure of the battery packaging film. In specific implementation, the sealing process of the two packaging sections 1 is achieved with the assistance of an external sealing head. During the battery packaging film sealing process, to ensure sealing quality, the external sealing head applies pressure to the hot melt adhesive-coated packaging section 1 to improve sealing quality. While the aforementioned pressure applied to the packaging section 1 by the external device is necessary, it can also cause the hot melt adhesive used for sealing to extend outwards and leak. Once the amount of hot melt adhesive leakage accumulates to a certain threshold, the two packaging sections 1 will face the risk of "false sealing" due to a significant reduction in the amount of hot melt adhesive. "False sealing" means that the sealing fails to achieve the expected effect, resulting in damage to the battery's airtightness. Generally, the small size of lithium-ion polymer batteries means that the border width rarely results in hot melt adhesive leakage during the sealing process. However, as electronic devices increasingly require smaller polymer battery radii (especially for soft-button lithium-ion batteries with specific soft-button diameter requirements), the width of the battery packaging film's border (specifically, the aluminum-plastic film in this application) is reduced to ensure the perforation depth can accommodate the battery's radius requirements. This leads to hot melt adhesive overflow during the sealing process. Therefore, this application addresses this technical issue by improving the battery packaging film for encapsulating battery cells.

[0047] Furthermore, the battery packaging film of this application includes two symmetrically arranged packaging portions 1. Each packaging portion 1 has an assembly cavity 11 for assembling battery cells. The packaging portion 1 also includes a sealing portion 12 and an extension portion 13 disposed outside the sealing portion 12. The sealing portion 12, located outside the assembly cavity 11, is used to seal the two packaging portions 12 together with hot melt adhesive. The extension portion 13, located outside the sealing portion 12, receives the hot melt adhesive calendered during the sealing process. The extension portion 13 includes a first extension portion 131 and a second extension portion 132. The battery cell's electrode tab extends to the outside of the packaging film through the first extension portion 131. Along the radial direction of the assembly cavity 11, the size of the first extension portion 131 is smaller than the size of the second extension portion 132. Specifically, in this application, the dimensions of the first extension portion 131 and the second extension portion 132 are preferably thickness dimensions.

[0048] Specifically, the principle behind this application's use of the first extension 131 and the second extension 132 to prevent hot melt adhesive from overflowing during cell encapsulation and to ensure that the frame does not exceed the thickness of the soft-pack lithium-ion polymer battery after the second encapsulation trimming is as follows: As the diameter of existing soft-pack polymer lithium-ion batteries decreases, the pitting depth of their packaging film also decreases. This inevitably requires an adaptive reduction in the size of the unencapsulated extension 13. In this application, although the first extension 131 has a shorter design, the second extension 132 is larger than the first extension 131. This provides a design that extends the area of ​​the extension 13 that does not involve the battery tabs, compared to the prior art which directly reduces the size of the extension 13. This allows the hot melt adhesive overflowing during encapsulation to be absorbed by the second extension 132, preventing it from overflowing onto the battery body and thus ensuring the battery's sealing and integrity. In addition, the width of the second extension 132 is greater than that of the first extension 131, so that even if part of the second extension 132 is cut off during secondary packaging, the size of the battery body will not be affected, thus ensuring the flatness of the battery packaging film and the integrity of the seal.

[0049] To further improve the performance of the battery packaging film, this application also provides an air bag 3, which is connected to the second extension 132 and has a sealing area 31. The air bag 3 can effectively absorb excess gas generated during the sealing process, preventing gas from accumulating inside the battery, thereby improving the battery's safety and stability. The sealing area 31 of the air bag 3 is designed to seal the air bag 3, after secondary trimming, together with the battery body during secondary sealing, ensuring a tight fit between the air bag 3 and the battery body, further enhancing the battery's sealing performance.

[0050] In summary, this utility model effectively solves the problems of hot melt adhesive overflow and inaccurate control of battery frame size in the prior art by improving the structural design of the battery packaging film, thereby improving the integrity and flatness of the soft-pack battery. At the same time, the design of the air bag 3 enhances the safety and stability of the battery.

[0051] Implementation Method 2

[0052] like Figure 1-3As shown, unlike Embodiment 1, in order to further demonstrate the dimensional difference between the first extension 131 and the second extension 132 of this application, the dimensions of the first extension 131 are D1 and the dimensions of the second extension 132 are D2 along the radial direction of the assembly cavity 11. The value range of D1 is 0.3mm-0.4mm, and the value range of D2 is 0.6mm-0.7mm. In specific implementation, the dimensions of both the first extension 131 and the second extension 132 are preferably width values; the preferred value for D1 is any one of 0.3mm, 0.31mm, 0.32mm, 0.33mm, 0.34mm, 0.35mm, 0.36mm, 0.37mm, 0.38mm, 0.39mm, and 0.4mm; the preferred value for D2 is any one of 0.6mm, 0.61mm, 0.62mm, 0.63mm, 0.64mm, 0.65mm, 0.66mm, 0.67mm, 0.68mm, 0.69mm, and 0.7mm. This dimensional design ensures that during the encapsulation process, the first extension 131 effectively limits the overflow of hot melt adhesive, while the second extension 132 has sufficient space to absorb the overflowing hot melt adhesive, thereby preventing the hot melt adhesive from affecting the battery body.

[0053] Furthermore, the first extension 131 is provided with a tab groove 1311, through which the tab extends out of the packaging film. The tab groove 1311 is an improvement on existing polymer lithium-ion battery packaging structures. Considering that in existing technologies, the tab is often directly placed between two packaging portions 1, when the tab extends out of the first extension 131, it is squeezed by the two first extension portions 131, causing the first extension 131 to bend and form a structure similar to a tab groove. In this application, the design of the tab groove 1311 effectively protects the tab during battery packaging, preventing damage during the packaging process. The size of the tab groove 1311 matches the size of the tab, ensuring that the tab can smoothly extend to the outside of the packaging film through the tab groove 1311 during packaging, while ensuring the connection stability and sealing between the tab and the battery body.

[0054] Specifically, each package portion 1 is provided with two tab grooves 1311, which are symmetrically arranged on both sides of the arc length direction of the first extension portion 131.

[0055] Furthermore, the groove edge of the tab groove near the second extension 132 is called the first side 1321, and the position where the second extension 132 and the first extension 131 are connected is called the second side 1312. The distance between the first side 1321 and the second side 1312 is D. 3；The value of D3 ranges from 0.2mm to 0.3mm. In specific implementation, the preferred value range of D3 is any one of the following: 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, and 0.3mm.

[0056] This size design ensures sufficient space between the tab groove 1311 and the second extension 132, allowing the tab to smoothly extend to the outside of the packaging film through the tab groove 1311 during the packaging process, while avoiding friction or damage between the tab and the second extension 132. Furthermore, the design of the tab groove 1311 also considers the stability of its connection with the battery body, ensuring the battery's sealing performance.

[0057] Other aspects that are the same as in Implementation Method 1 will not be described again in this implementation method.

[0058] Implementation Method 3

[0059] like Figure 1-3 As shown, unlike Embodiment 1, to further demonstrate the encapsulation principle of the battery packaging film of this application, the battery packaging film of this application further includes a connecting portion 2, which is used to connect the two encapsulation portions 1 together. Through the design of the connecting portion 2, a more robust encapsulation effect can be achieved, ensuring that the battery will not become loose due to vibration or impact during the encapsulation process.

[0060] Furthermore, one end of the connecting part 2 is connected to the first extension 131 of one encapsulation part 1, and the other end of the connecting part 2 is connected to the first extension 131 of another encapsulation part 1. The inner side of the connecting part 2 is also treated with hot melt adhesive, and the outer side of the connecting part 2 is also an unsealed frame. This further alleviates the hot melt adhesive overflowing from the encapsulation part 1 at the tab groove 1311 corresponding to the first extension 131 during the encapsulation process.

[0061] Furthermore, the two encapsulation parts 1 are designed symmetrically along the length direction (Y-axis) of the connecting part 2. This ensures that the two encapsulation parts 1 maintain consistency and symmetry during the encapsulation process, thereby improving the overall encapsulation effect and battery stability. The length design of the connecting part 2 has also been optimized to ensure that it can fully adapt to changes in battery size during the encapsulation process, while avoiding unnecessary pressure or damage to the battery body.

[0062] Furthermore, this application also provides a pouch battery, manufactured by cutting any of the battery packaging films shown above. In the final stage of the pouch battery encapsulation process, the top seal head is intentionally offset from the tab by approximately 0.2 mm, the top seal extension at the tab position is increased by approximately 0.4 mm, and the extension further away from the tab position is increased by 0.3-0.4 mm, ensuring that the top seal adhesive does not leave the unsealed area. The second extension 132 is then adaptively cut to achieve the required battery packaging film size. Because the second extension 132 is relatively wide, even if part of the second extension 132 is cut off, it will not affect the size and sealing performance of the battery body. In addition, by optimizing the cutting position, the flatness of the battery packaging film and the integrity of the seal can be ensured, thereby further improving the stability and safety of the battery.

[0063] In summary, this utility model effectively solves the problems of hot melt adhesive overflow and inaccurate control of battery frame size in the prior art by improving the structural design and packaging process of the battery packaging film, thereby improving the integrity and flatness of the soft-pack battery. At the same time, the design of the air bag 3 enhances the safety and stability of the battery.

[0064] Other aspects that are the same as in Implementation Method 1 will not be described again in this implementation method.

[0065] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery packaging film, comprising two symmetrical packaging parts (1) provided with assembly cavities (11) for assembling battery cores, characterized in that, the packaging part (1) further comprises a sealing part (12) and an extension part (13) provided outside the sealing part (12); the sealing part (12) is located outside the assembly cavity (11) and is used for packaging the two packaging parts (1) together by hot melt adhesive; the extension part (13) is located outside the sealing part (12) and receives the hot melt adhesive extruded during the packaging of the sealing part (12); the extension part (13) comprises a first extension part (131) and a second extension part (132), and the tabs of the battery core extend to the outside of the packaging film through the first extension part (131); along the radial direction of the assembly cavity (11), the size of the first extension part (131) is smaller than the size of the second extension part (132).

2. The battery packaging film of claim 1, wherein, Along the radial direction of the assembly cavity (11), the size of the first extension part (131) is D1, and the size of the second extension part (132) is D2, the value range of D1 is 0.3mm-0.4mm, and the value range of D2 is 0.6mm-0.7mm.

3. The battery packaging film of claim 2, wherein, The first extension part (131) is provided with a tab slot (1311), and the tab extends out of the packaging film through the tab slot (1311).

4. The battery packaging film of claim 3, wherein, Each of the packaging parts (1) is provided with two tab slots (1311), and the two tab slots (1311) are symmetrically arranged on both sides of the arc length direction of the first extension part (131).

5. The battery packaging film of claim 3, wherein, The slot edge of the tab slot (1311) close to the second extension part (132) is a first edge (1321), the position where the second extension part (132) and the first extension part (131) are connected is a second edge (1312), and the distance value between the first edge (1321) and the second edge (1312) is D3; The value range of D3 is 0.2mm-0.3mm.

6. The battery packaging film of claim 1, wherein, Further comprising a connecting part (2) for connecting the two packaging parts (1) together.

7. The battery packaging film of claim 6, wherein, One end of the connecting part (2) is connected with the first extension part (131) of one of the packaging parts (1), and the other end of the connecting part (2) is connected with the first extension part (131) of the other packaging part (1).

8. The battery packaging film of claim 6, wherein, The two packaging parts (1) are symmetrically designed through the symmetric axis in the length direction of the connecting part (2).

9. The battery packaging film of claim 1, wherein, Further comprising an air bag (3) connected with the second extension part (132), and the air bag is provided with a packaging area (31).

10. A pouch battery, characterized by, The battery packaging film is cut and made according to any one of claims 1-9.

Images