Soft package battery cell sealing structure and sealing head
By setting a pre-sealing structure and an exhaust channel inside the airbag, the problem of electrolyte corrosion of the aluminum-plastic film was solved, improving the final sealing yield and safety performance of the soft-pack battery cells.
Patent Information
- Application Number
- CN202423250280.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2034-12-26
AI Technical Summary
After electrolyte is injected into the soft-pack battery cell, the polypropylene layer of the aluminum-plastic film is corroded, affecting the final sealing effect and sealing strength, resulting in low yield and leakage safety hazards.
A pre-sealing structure is set inside the airbag, including first and second pre-sealing strips, forming a V-shaped structure. The exhaust channel design allows the electrolyte to fall back to the cell area, preventing it from remaining inside the airbag and soaking the pre-sealing strips.
It improves the final sealing yield, enhances the safety performance of the battery cells, and prevents final sealing defects caused by long-term immersion in electrolyte.
Smart Images
Figure CN223843003U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, and in particular to a sealing structure and end cap for a soft-pack battery cell. Background Technology
[0002] Soft-pack battery cells are usually covered with aluminum-plastic film for perforation. The outermost layer of the aluminum-plastic film is mainly a nylon layer, and the inner layers are aluminum, adhesive and polypropylene, forming a composite structure. Utility Model Content
[0003] After the battery cell is injected with electrolyte, the polypropylene layer inside the aluminum-plastic film is immersed in the electrolyte for a long time during the formation, chemical formation, and aging process. This causes corrosion of the aluminum-plastic film, affecting the subsequent final sealing effect and sealing strength. This poses a potential hazard to yield checks during battery cell production and leakage safety during subsequent use. To overcome the shortcomings and deficiencies of poor sealing during the final sealing process, the purpose of this invention is to provide a sealing structure and end cap for soft-pack battery cells, improving the final sealing yield and enhancing the safety performance of the battery cells.
[0004] The objective of this utility model is achieved through the following technical solution:
[0005] A sealing structure for a soft-pack battery cell includes a battery cell area and an airbag located on one side of the battery cell area. The airbag contains a pre-sealing structure, which includes at least a first pre-sealing strip and a second pre-sealing strip. The first pre-sealing strip is positioned inside the airbag and connected to the battery cell area, with an exhaust channel for communication between the battery cell area and the airbag. The first pre-sealing strip includes a first connecting end near the exhaust channel, which is connected to a first end of the second pre-sealing strip. A second end of the second pre-sealing strip extends away from the battery cell area. A final sealing area is provided on the first pre-sealing strip for final sealing the soft-pack battery cell.
[0006] In one embodiment, there is one first pre-sealing strip and one second pre-sealing strip; there is a first gap between the first connecting end of the first pre-sealing strip and the inner wall of the airbag, the first gap being the exhaust channel; the first pre-sealing strip further includes a second connecting end away from the exhaust channel, the second connecting end being connected to the inner wall of the airbag.
[0007] In one embodiment, there is one first pre-sealing strip and two second pre-sealing strips; the first pre-sealing strip includes two first connecting ends, and both first connecting ends of the first pre-sealing strip have a first gap with the inner wall of the airbag, and both first gaps are the exhaust channels; the two first connecting ends of the first pre-sealing strip are respectively connected to the first ends of the two second pre-sealing strips.
[0008] In one embodiment, there are two first pre-sealing strips, so there are two second pre-sealing strips; there is a first gap between the two first pre-sealing strips, and the first gap is the exhaust channel; the first connecting end of each of the two first pre-sealing strips is connected to the first end of one of the second pre-sealing strips; the two first pre-sealing strips also include a second connecting end away from the exhaust channel, and the second connecting end of each of the two first pre-sealing strips is connected to the inner wall of the airbag.
[0009] In one embodiment, the width of the exhaust channel is W1, where 3mm ≤ W1 ≤ 5mm.
[0010] In one embodiment, the first connecting end of the first pre-seal strip and the first end of the second pre-seal strip form an angle α at the connection point, where 0° < α < 90°.
[0011] In one embodiment, the width of the first pre-seal strip is B1, the width of the final seal area is B, B1 is greater than B, and the difference between B1 and B is in the range of 0.5mm-3mm.
[0012] In one embodiment, the pre-sealing structure further includes a third pre-sealing strip, one end of which is connected to the second end of the second pre-sealing strip away from the cell area, and the connection forms an included angle β, where 30° < β < 150°.
[0013] In one embodiment, the other end of the third pre-seal strip away from the second pre-seal strip is provided with a second gap between it and the inner wall of the airbag, the width of the second gap being W2, 3mm≤W2≤5mm.
[0014] In one embodiment, the thickness of the second pre-seal strip is D2, and the thickness of the third pre-seal strip is D3; wherein, 2mm≤D2≤3mm, 2mm≤D3≤3mm.
[0015] In one embodiment, the airbag has an opening on the side away from the battery cell area for injecting electrolyte into the battery cell area; after the electrolyte injection is completed, a fourth pre-seal strip is provided at the opening to seal the airbag.
[0016] This utility model also provides a sealing head, including a pre-sealing head, which is used to form the pre-sealed structure as described above.
[0017] The beneficial effects of this utility model are as follows: By setting a pre-sealing structure and an exhaust channel inside the airbag, the second pre-sealing strip of the pre-sealing structure is connected to the first pre-sealing strip near the exhaust channel, and the second pre-sealing strip extends away from the cell area. The second pre-sealing strip and the first pre-sealing strip form a V-shaped structure, which allows the electrolyte entering the airbag to fall back into the cell area along the second pre-sealing strip. This avoids the electrolyte remaining in the airbag and soaking the first pre-sealing strip, thereby avoiding the problem of electrolyte soaking the final sealing area for a long time, which would cause subsequent final sealing defects. This is conducive to improving the final sealing yield and enhancing the safety performance of the cell. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram of the soft-pack battery cell sealing structure of the first embodiment of this utility model without a final seal and a fourth pre-seal;
[0020] Figure 2 yes Figure 1 A schematic diagram of the pre-sealed structure in the diagram;
[0021] Figure 3 yes Figure 1 A schematic diagram showing the structure of the final seal and the fourth pre-seal;
[0022] Figure 4 This is a schematic diagram of the sealing structure of the soft-pack battery cell according to the second embodiment of this utility model;
[0023] Figure 5 yes Figure 4 A schematic diagram of the pre-sealed structure in the diagram;
[0024] Figure 6 This is a schematic diagram of the sealing structure of the soft-pack battery cell according to the third embodiment of this utility model;
[0025] Figure 7 yes Figure 6 A schematic diagram of the pre-sealed structure in the image.
[0026] In the diagram: 1. Cell area; 11. Tab; 2. Airbag; 21. Opening; 22. Fourth pre-seal strip; 3. Pre-seal structure; 31. First pre-seal strip; 311. First connecting end; 312. Second connecting end; 32. Second pre-seal strip; 33. Third pre-seal strip; 4. Final sealing area; 5. Exhaust channel; 6. Second gap; 7. Final seal strip; 8. Top seal strip. Detailed Implementation
[0027] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of this utility model. Based on the description of this utility model, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this utility model.
[0028] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0029] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0030] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.
[0031] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.
[0032] This utility model provides a sealing structure for a soft-pack battery cell, such as... Figures 1 to 3As shown, the device includes a battery cell area 1 and an airbag 2 located on one side of the battery cell area 1. The battery cell area 1 includes a battery cell housing (not shown) and a bare battery cell (not shown) located inside the battery cell housing. The battery cell housing and the airbag 2 are an integrated aluminum-plastic film, which is divided into two parts by encapsulation. The airbag 2 is provided with a pre-sealing structure 3, which includes at least a first pre-sealing strip 31 and a second pre-sealing strip 32. The first pre-sealing strip 31 is located inside the airbag 2 at the position connected to the battery cell area 1, and the battery cell area 1 and the airbag 2 are connected. An exhaust channel 5 is provided between the two for communication. The exhaust channel 5 is used to discharge the gas generated in the cell area 1 into the air bag 2 during the cell formation process. The first pre-sealing strip 31 includes a first connecting end 311 near the exhaust channel 5. The first connecting end 311 of the first pre-sealing strip 31 is connected to the first end of the second pre-sealing strip 32. The second end of the second pre-sealing strip 32 extends away from the cell area 1. A final sealing area 4 is provided on the first pre-sealing strip 31. The final sealing area 4 is used to final seal the soft-pack cell.
[0033] In this embodiment, a pre-sealing structure 3 is provided inside the airbag 2. During the formation process of the soft-pack battery cell, the battery cell area 1 is squeezed. When the gas is squeezed out of the battery cell area 1, it also causes the electrolyte in the battery cell area 1 to flow upward through the exhaust channel 5 to the airbag 2. In this embodiment, near the exhaust channel 5, the second pre-sealing strip 32 and the first pre-sealing strip 31 of the pre-sealing structure 3 are connected, and the second pre-sealing strip 32 extends away from the battery cell area 1. The second pre-sealing strip 32 and the first pre-sealing strip 31 form a V-shaped structure, which allows the electrolyte entering the airbag 2 to fall back into the battery cell area 1 along the second pre-sealing strip 32. This prevents the electrolyte flowing from the battery cell area 1 into the airbag 2 from remaining in the airbag 2, avoiding electrolyte residue in the airbag 2 from soaking the first pre-sealing strip 31. This avoids the problem of electrolyte soaking the final sealing area 4 for a long time, which would cause subsequent final sealing defects. This is beneficial to improving the final sealing yield and enhancing the safety performance of the battery cell.
[0034] As one implementation method, such as Figures 1 to 3As shown, in the first embodiment, there is one first pre-sealing strip 31 and one second pre-sealing strip 32; there is a first gap between the first connecting end 311 of the first pre-sealing strip 31 and the inner wall of the airbag 2, and the first gap is an exhaust channel 5; the first pre-sealing strip 31 also includes a second connecting end 312 away from the exhaust channel 5, the second connecting end 312 is connected to the inner wall of the airbag 2, and the second pre-sealing strip 32 and the first pre-sealing strip 31 form a V-shaped structure. In this embodiment, the pre-sealing structure 3 includes one first pre-sealing strip 31 and one second pre-sealing strip 32; during the formation and exhaust process of the soft-pack battery cell, the gas generated in the battery cell area 1 is discharged into the airbag 2 through the first gap on the side of the first connecting end 311 of the first pre-sealing strip 31, and the electrolyte enters the airbag 2 through the first gap and can fall back to the battery cell area 1 along the second pre-sealing strip 32 to avoid the electrolyte remaining in the airbag 2 and soaking the first pre-sealing strip 31. Among them, the first connecting end 311 of the first pre-seal strip 31 has a first gap with the inner wall of the airbag 2, that is, an exhaust channel 5 is left between the top seal strip 8 to allow gas communication between the battery cell area 1 and the airbag 2; the top seal strip 8 leads out the electrode tab 11.
[0035] As one implementation method, such as Figure 4 and Figure 5 As shown, in the second embodiment, there is one first pre-sealing strip 31 and two second pre-sealing strips 32. The first pre-sealing strip 31 includes two first connecting ends 311, and both first connecting ends 311 of the first pre-sealing strip 31 have a first gap with the inner wall of the airbag 2. Both first gaps are exhaust channels 5. The two first connecting ends 311 of the first pre-sealing strip 31 are respectively connected to the first ends of the two second pre-sealing strips 32, that is, the two ends of the first pre-sealing strip 31 and the two second pre-sealing strips 32 form a V-shaped structure. In this embodiment, the pre-sealing structure 3 includes one first pre-sealing strip 31 and two second pre-sealing strips 32. During the formation and exhaust process of the soft-pack battery cell, the gas generated in the battery cell area 1 is discharged into the airbag 2 through the first gaps at both ends of the first pre-sealing strip 31. After the electrolyte enters the airbag 2 through the first gap, it can fall back to the battery cell area 1 along the two second pre-sealing strips 32 to avoid the electrolyte remaining in the airbag 2 and soaking the first pre-sealing strip 31.
[0036] As one implementation method, such as Figure 6 and Figure 7As shown, in the third embodiment, there are two first pre-sealing strips 31, so there are two second pre-sealing strips 32; there is a first gap between the two first pre-sealing strips 31, which is an exhaust channel 5; the first connecting end 311 of each of the two first pre-sealing strips 31 is connected to the first end of one second pre-sealing strip 32; the two first pre-sealing strips 31 also include a second connecting end 312 away from the exhaust channel 5, and the second connecting end 312 of the two first pre-sealing strips 31 are connected to the inner wall of the airbag 2, and the two second pre-sealing strips 32 and the two first pre-sealing strips 31 form two V-shaped structures. In this embodiment, the pre-sealing structure 3 includes two first pre-sealing strips 31 and two second pre-sealing strips 32; during the formation and exhaust process of the soft-pack battery cell, the gas generated in the battery cell area 1 is discharged into the airbag 2 through the exhaust channel 5 between the two first pre-sealing strips 31, and the electrolyte enters the airbag 2 through the exhaust channel 5 and can fall back to the battery cell area 1 along the two second pre-sealing strips 32 to avoid the electrolyte remaining in the airbag 2 and soaking the first pre-sealing strips 31.
[0037] In the three embodiments described above, the pre-sealing structure 3 in the first embodiment is simpler, including only a first pre-sealing strip 31 and a second pre-sealing strip 32, and can be preferred. Of course, three or more exhaust channels 5 can be provided. At one exhaust channel 5 between two first pre-sealing strips 31, there is a connection structure between two first pre-sealing strips 31 and second pre-sealing strips 32; at the exhaust channel 5 between the first pre-sealing strip 31 and the inner wall of the airbag 2, there is a connection structure between the first pre-sealing strip 31 and the second pre-sealing strip 32; these will not be described in detail here; and in one embodiment, exhaust channels 5 can be provided simultaneously between two first pre-sealing strips 31 and between the first pre-sealing strip 31 and the inner wall of the airbag 2.
[0038] As one implementation method, such as Figure 1 , Figure 4 and Figure 6 As shown, the width of the exhaust channel 5 is W1, 3mm≤W1≤5mm. During the formation of the soft-pack battery cell, the gas generated in the battery cell area 1 is discharged into the airbag 2 through the exhaust channel 5.
[0039] As one implementation method, such as Figure 2 , Figure 5 and Figure 7As shown, the first connecting end 311 of the first pre-seal strip 31 and the first end of the second pre-seal strip 32 form an angle α at the connection point, where 0° < α < 90°. That is, the second pre-seal strip 32 is inclined upward and positioned away from the exhaust channel 5, leaving a larger space between the second pre-seal strip 32 and the inner wall of the airbag 2. This allows the electrolyte in the battery cell area 1 to enter the airbag 2 from the exhaust channel 5, preventing the electrolyte from entering the space between the second pre-seal strip 32 and the first pre-seal strip 31 and soaking the first pre-seal strip 31, which would affect the subsequent setting of the final seal 7 at the position of the first pre-seal strip 31. The second pre-seal strip 32 can be a straight line or a curve with a small curvature.
[0040] As one implementation method, such as Figures 1 to 3 As shown, the width of the first pre-seal strip 31 is B1, the width of the final sealing area 4 is B, B1 is greater than B, and the difference between B1 and B is in the range of 0.5mm-3mm; to ensure that during final sealing, the final seal strip 8 is inside the first pre-seal strip 31.
[0041] As one implementation method, such as Figures 1 to 7 As shown, the pre-sealing structure 3 also includes a third pre-sealing strip 33. One end of the third pre-sealing strip 33 is connected to the second end of the second pre-sealing strip 32, and the connection forms an included angle β, 30° < β < 150°. The electrolyte squeezed out during the cell formation can be blocked by the third pre-sealing strip 33, so that the electrolyte can flow smoothly back to the cell area 1 after the formation is completed.
[0042] As one implementation method, such as Figure 3 As shown, the other end of the third pre-seal strip 33 away from the second pre-seal strip 32 is provided with a second gap 6 between it and the inner wall of the airbag 2. The width of the second gap 6 is W2, 3mm≤W2≤5mm. The second gap 6 is also used for venting. During the cell formation process, when a large amount of gas is discharged from the cell area 1, the gas enters the rear airbag 2 through the first gap and then passes through the second gap 6 to fill the entire airbag 2. The setting of the second gap 6 makes the interior of the airbag 2 interconnected to accommodate gas. When the soft-pack cell generates gas, the space of the airbag 2 can be fully utilized. The third pre-seal strip 33 also has the function of preventing the electrolyte squeezed out during the pressurized formation process from entering the dead corner of the airbag.
[0043] As one implementation method, such as Figure 2 , Figure 5 and Figure 7 As shown, the thickness of the second pre-seal strip 32 is D2, and the thickness of the third pre-seal strip 33 is D3; wherein, 2mm≤D2≤3mm, 2mm≤D3≤3mm.
[0044] As one implementation method, such as Figure 1 and Figure 3As shown, the airbag 2 has an opening 21 on the side away from the battery cell area 1 for injecting electrolyte into the battery cell area 1; after the electrolyte injection is completed, a fourth pre-seal strip 22 is provided at the opening 21 to seal the airbag 2. The second gap 6 is the gap between the other end of the third pre-seal strip 33 away from the second pre-seal strip 32 and the fourth pre-seal strip 22.
[0045] This utility model also provides a sealing head (not shown), including a pre-sealing head, which is used to form the pre-sealed structure 3 as described above. The pre-sealing head has a sealing temperature between 165-185°C, a sealing time between 1-3 seconds, and a sealing head pressure between 0.2-1 MPa.
[0046] In one embodiment, the pre-sealing head includes a first pre-sealing head and a second pre-sealing head, wherein the first pre-sealing head is used to form a first pre-sealing strip 31 and the second pre-sealing head is used to form a second pre-sealing strip 32.
[0047] In one embodiment, the pre-sealing head also includes a third pre-sealing head, which is used to form a third pre-seal 33.
[0048] In one embodiment, the end cap also includes a fourth pre-end cap, which is used to form a fourth pre-seal 22.
[0049] In one implementation, the end cap also includes a final end cap, which is used to form a final seal 7.
[0050] As one implementation method, the end cap is made of pure copper.
[0051] The specific process of forming the soft-pack battery cell sealing structure by encapsulation is as follows: After the bare battery cell is wrapped with aluminum-plastic film, a top seal is first formed to create a top seal strip 8 and a side seal on one side. Then, electrolyte is injected into the battery cell area 1 through the opening 21 of the airbag 2. After the electrolyte is injected, a fourth pre-seal strip 22 is formed by sealing the opening 21 of the fourth pre-seal head to seal the airbag 2. Then, a pre-seal structure 3 (including a first pre-seal strip 31, a second pre-seal strip 32, and a third pre-seal strip 33) is formed by sealing the connection between the battery cell area 1 and the airbag 2 with the pre-seal head, which separates the battery cell area 1 and the airbag 2 and provides an exhaust channel 5.
[0052] During the formation process of the battery cell, both gas and electrolyte can enter the air bag 2 through the exhaust channel 5. The electrolyte can flow back to the battery cell area 1 through the inclined second pre-sealing strip 32 and third pre-sealing strip 33 to prevent the electrolyte from soaking the final sealing area 4. After the formation is completed, the final sealing area 4 is sealed by the final sealing head to form the final sealing strip 7, which blocks the exhaust channel 5 to seal the battery cell area 1. Finally, the air bag 2 is cut off to obtain the body structure of the soft-pack battery cell.
[0053] This invention provides a pre-sealing structure 3 and an exhaust channel 5 within the airbag 2. Near the exhaust channel 5, the second pre-sealing strip 32 of the pre-sealing structure 3 is connected to the first pre-sealing strip 31, with the second pre-sealing strip 32 extending away from the cell area 1. The second pre-sealing strip 32 and the first pre-sealing strip 31 form a V-shaped structure, allowing the electrolyte entering the airbag 2 to fall back into the cell area 1 along the second pre-sealing strip 32. This prevents electrolyte residue from remaining in the airbag and soaking the first pre-sealing strip 31, thus avoiding long-term soaking of the final sealing area 4 by the electrolyte, which could lead to subsequent poor final sealing. This improves the final sealing yield and enhances the safety performance of the cell.
[0054] Specifically:
[0055] (1) The sealing structure design of the lithium-ion battery after liquid injection of this utility model, the pre-sealing structure 3 can be regarded as a whole composed of the first pre-sealing strip 31, the second pre-sealing strip 32 and the third pre-sealing strip 33. After the cell is injected with liquid and placed under negative pressure, a pre-sealing structure 3 is added inside the air bag while the air bag is sealed normally;
[0056] (2) In the pre-sealing structure 3, the first pre-sealing strip 31 is shorter than the final sealing strip 7, and an exhaust channel 5 is left between it and the top sealing strip 8 to connect the cell area 1 and the airbag 2. The exhaust channel 5 is about 3mm-5mm wide, so that the gas generated during the formation process can smoothly enter the airbag 2. The first pre-sealing strip 31 is 0.5mm-3mm wider than the final sealing strip 7 to ensure that the final sealing structure can fall entirely within the first pre-sealing strip 31 during final sealing.
[0057] (3) The sealing thickness of the pre-sealed structure 3 should be 15%-30% thicker than the final seal 7. The sealing temperature, time and pressure parameters here can be referenced from the final seal parameters, and some adjustments can be made based on the final seal parameters to achieve the sealing effect.
[0058] (4) The second pre-sealing strip 32 of the pre-sealing structure 3 is a slope structure. This structure is designed to ensure that the electrolyte in the cell area 1 is squeezed out during the pressurized formation of the soft-pack cell, and that the electrolyte can flow back into the cell area 1 structure after the cell formation is completed.
[0059] (5) The pre-sealed structure 3 ensures that the polypropylene in the connection part (final sealing area 4) between the cell area 1 and the air bag 2 is not soaked in electrolyte during the pressurized formation process, and is not soaked in electrolyte during the aging and formation process after the cell is injected with electrolyte.
[0060] (6) In the pre-sealing structure 3, there is a second gap 6 of 3-5mm between the third pre-sealing strip 33 and the fourth pre-sealing strip 22 of the airbag 2 for gas flow. When the soft-pack battery cell is formed and gas is generated, the space of the airbag can be fully utilized. The third pre-sealing strip 33 also has the function of preventing the electrolyte squeezed out during the pressurized formation process from entering the dead corner of the airbag.
[0061] (7) After the pre-sealing structure 3 is added inside the airbag 2 after liquid injection, the problem of poor final sealing strength caused by the electrolyte soaking in the final sealing area of the battery cell is avoided, the yield of the battery cell is improved, the detection frequency is reduced, and the safety performance of the battery cell is increased.
[0062] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content without departing from the scope of the technical solution of the present utility model. These are equivalent embodiments with equivalent changes. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.
Claims
1. A sealing structure for a soft-pack battery cell, characterized in that, The device includes a battery cell area (1) and an airbag (2) located on one side of the battery cell area (1). The airbag (2) is provided with a pre-sealing structure (3). The pre-sealing structure (3) includes at least a first pre-sealing strip (31) and a second pre-sealing strip (32). The first pre-sealing strip (31) is located in the airbag (2) and connected to the battery cell area (1). An exhaust channel (5) is provided between the battery cell area (1) and the airbag (2) for communication. The first pre-sealing strip (31) includes a first connecting end (311) near the exhaust channel (5). The first connecting end (311) of the first pre-sealing strip (31) is connected to the first end of the second pre-sealing strip (32). The second end of the second pre-sealing strip (32) extends away from the battery cell area (1). A final sealing area (4) is provided on the first pre-sealing strip (31). The final sealing area (4) is used to final seal the soft-pack battery cell.
2. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, There is one first pre-sealing strip (31) and one second pre-sealing strip (32); there is a first gap between the first connecting end (311) of the first pre-sealing strip (31) and the inner wall of the airbag (2), and the first gap is the exhaust channel (5); the first pre-sealing strip (31) also includes a second connecting end (312) away from the exhaust channel (5), and the second connecting end (312) is connected to the inner wall of the airbag (2).
3. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, There is one first pre-sealing strip (31) and two second pre-sealing strips (32); the first pre-sealing strip (31) includes two first connecting ends (311), and both first connecting ends (311) of the first pre-sealing strip (31) have a first gap with the inner wall of the airbag (2), and both first gaps are the exhaust channels (5); the two first connecting ends (311) of the first pre-sealing strip (31) are respectively connected to the first ends of the two second pre-sealing strips (32).
4. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, There are two first pre-sealing strips (31), so there are two second pre-sealing strips (32); there is a first gap between the two first pre-sealing strips (31), which is the exhaust channel (5); the first connecting end (311) of each of the two first pre-sealing strips (31) is connected to the first end of one of the second pre-sealing strips (32); the two first pre-sealing strips (31) also include a second connecting end (312) away from the exhaust channel (5), and the second connecting end (312) of the two first pre-sealing strips (31) is connected to the inner wall of the airbag (2).
5. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, The width of the exhaust channel (5) is W1, 3mm≤W1≤5mm.
6. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, The first connecting end (311) of the first pre-seal strip (31) and the first end of the second pre-seal strip (32) form an angle α at the connection point, where 0° < α < 90°.
7. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, The width of the first pre-sealing strip (31) is B1, the width of the final sealing area (4) is B, B1 is greater than B, and the difference between B1 and B is in the range of 0.5mm-3mm.
8. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, The pre-sealing structure (3) further includes a third pre-sealing strip (33), one end of which is connected to the second end of the second pre-sealing strip (32) away from the cell area (1), and the connection forms an included angle β, 30° < β < 150°.
9. The soft-pack battery cell sealing structure as described in claim 8, characterized in that, The third pre-seal strip (33) has a second gap (6) between its other end away from the second pre-seal strip (32) and the inner wall of the airbag (2). The width of the second gap (6) is W2, 3mm≤W2≤5mm.
10. The soft-pack battery cell sealing structure as described in claim 8, characterized in that, The thickness of the second pre-seal strip (32) is D2, and the thickness of the third pre-seal strip (33) is D3; wherein, 2mm≤D2≤3mm, 2mm≤D3≤3mm.
11. The soft-pack battery cell sealing structure as described in claim 1, characterized in that, The airbag (2) has an opening (21) on the side away from the cell area (1) for injecting electrolyte into the cell area (1); After the electrolyte injection is completed, a fourth pre-seal strip (22) is provided at the opening (21) to seal the airbag (2).
12. A type of end cap, characterized in that, Includes a pre-sealing head, said pre-sealing head being used to form a pre-sealed structure (3) as described in any one of claims 1-11.