Batteries that can vent gas in a timely manner

Abstract

This invention provides a battery capable of timely venting, comprising an aluminum-plastic film, a venting device, and a battery cell encapsulated within the aluminum-plastic film. The venting device is used to discharge gas generated by the battery cell from the aluminum-plastic film. The aluminum-plastic film has a pre-reserved opening, and the venting device is connected to the pre-reserved opening. The venting device includes a housing and a venting assembly, which is matched to the housing. One end of the housing has multiple first through holes, which communicate with the inner cavity of the aluminum-plastic film. Gas generated by the battery cell is discharged from the aluminum-plastic film through the multiple first through holes under the action of the venting assembly. According to the embodiments of this invention, the venting device effectively and timely discharges gas generated by the battery cell, avoiding the use of DEGAS equipment, reducing the risk of corrosion caused by gas bag swelling attacking the aluminum-plastic film, and reducing the risk of electrode wrinkling and lithium plating caused by gas generation during formation, aging, and capacity testing. It is low-cost, highly operable, and highly safe.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion batteries, and more particularly to batteries capable of timely venting. Background Technology

[0002] Lithium-ion batteries are characterized by high energy density and lightweight design, which has driven the development of new energy vehicles. Silicon-based anodes, due to their high specific capacity, have become the preferred choice for high-energy-density batteries. However, due to their unique material properties, silicon-based anodes expand significantly during charge and discharge, which is detrimental to cell cycle life. Therefore, novel binders are being used to replace conventional binders. But this introduces a new problem: the new binders are rich in hydroxyl and carboxyl functional groups. These functional groups react during formation to produce condensation water, which then reacts with the electrolyte to generate a large amount of gas.

[0003] For pouch batteries, gases generated during the manufacturing process continuously accumulate in the gas pockets of the aluminum-plastic film and in the gaps between the electrodes and the separator. If these accumulated gases cannot be released in time, they may impact the casing and electrode surfaces, ultimately leading to poor insulation, lithium plating on the electrode surfaces, and unstable SEI film formation. This severely affects the battery's electrical performance, resulting in high self-discharge and even safety hazards. Therefore, effectively venting these internal gases during the manufacturing process is crucial.

[0004] Currently, soft-shell batteries such as pouch cells employ multiple degassing methods, enlarged aluminum-plastic film gas bags, and automatic venting valves to store or release gas. Multiple degassing affects the SEI film formation process, and the repeatedly encapsulated aluminum-plastic film is prone to damage and insulation problems, requiring additional equipment. Enlarging the aluminum-plastic film gas bag significantly increases material costs, and the larger gas bag also hinders continuous production processes such as cell handling. Installing an automatic venting valve requires the aluminum-plastic film gas bag to expand to a considerable extent, generating significant internal pressure before active venting can occur. Delayed venting may lead to insulation problems, lithium plating on the electrode surface, and unstable SEI film formation before active venting.

[0005] Therefore, how to ensure timely venting of pouch cells during the manufacturing process is an urgent problem to be solved. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a battery that can release gas in a timely manner, and can effectively release gas in a timely manner.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A battery capable of timely venting according to an embodiment of the present invention includes an aluminum-plastic film, a venting device, and a battery cell encapsulated in the aluminum-plastic film. The venting device is used to discharge gas generated by the battery cell from the aluminum-plastic film. The aluminum-plastic film has a pre-reserved opening, and the venting device is connected to the pre-reserved opening.

[0009] The exhaust device includes a housing and an exhaust assembly. The exhaust assembly is matched with the housing. One end of the housing is provided with a plurality of first through holes. The plurality of first through holes are connected to the inner cavity of the aluminum-plastic film. The gas generated by the battery cell is discharged from the aluminum-plastic film through the plurality of first through holes under the action of the exhaust assembly.

[0010] Furthermore, the housing is located inside the aluminum-plastic film and is disposed adjacent to the battery cell, and the exhaust assembly is connected to the reserved port.

[0011] Furthermore, the outer diameter of the housing is 5mm to 20mm.

[0012] Furthermore, the distance between the casing and the battery cell is 10mm to 30mm.

[0013] Furthermore, the aluminum-plastic film is provided with multiple fixing points, which are located at the bottom of the exhaust device.

[0014] Furthermore, the exhaust device is located outside the aluminum-plastic film, and the plurality of first through holes are connected to the reserved opening;

[0015] The exhaust device also includes a support member connected to the lower surface of the housing.

[0016] Furthermore, it also includes a connecting ring, which is sealed and connected to the reserved opening, and the outer wall of the connecting ring is made of the same material as the inner wall of the reserved opening.

[0017] Furthermore, the exhaust assembly includes a first seal, a moving plug, and a pull rod. The first seal is connected to the inner end of the housing and can form a seal with a plurality of first through holes. The moving plug is connected to the pull rod and divides the housing into a first space and a second space. The moving plug moves within the housing under the action of the pull rod to exhaust the gas discharged from the battery cell into the first space and then through the moving plug before being discharged.

[0018] Furthermore, the exhaust assembly also includes an exhaust channel that connects the first space, the moving plug, and the pull rod.

[0019] Furthermore, the exhaust assembly also includes a second seal that matches the inner cavity of the housing. The moving plug has a groove, and the second seal is located in the groove. When the exhaust assembly moves toward the first through hole, the gas in the first space flows into the exhaust channel and is discharged.

[0020] The above-described technical solution of the present invention has at least one of the following beneficial effects:

[0021] The battery disclosed in this invention can vent gas in a timely manner. It uses a venting device to effectively and promptly expel the gas generated by the cell, avoiding the use of DEGAS equipment, reducing the risk of corrosion caused by gas bag swelling attacking the aluminum-plastic film, and reducing the risk of electrode wrinkling and lithium plating caused by gas generation during formation, aging, and capacity testing. It is low in cost, highly operable, and highly safe. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a battery capable of timely venting, where the venting device is located inside an aluminum-plastic film, according to an embodiment of the present invention.

[0023] Figure 2 A schematic diagram of the battery cell structure when the venting device in a battery capable of timely venting is located outside the aluminum-plastic film, according to another embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the structure of the venting device in a battery capable of timely venting, provided in another embodiment of the present invention, when the venting device is located outside the aluminum-plastic film;

[0025] Figure 4 A schematic diagram of a venting device in a battery capable of timely venting, according to an embodiment of the present invention;

[0026] Figure 5 Another schematic diagram of the venting device in a battery capable of timely venting, provided in an embodiment of the present invention;

[0027] Figure 6 A side view of one end of the casing in a battery capable of timely venting, according to an embodiment of the present invention;

[0028] Figure 7 This is a side view of the other end of the casing of a battery capable of timely venting, according to an embodiment of the present invention.

[0029] Figure label:

[0030] 10. Aluminum-plastic film; 110. Reserved opening; 120. Fixing point; 20. Battery cell; 30. Exhaust device; 30a. First space; 30b. Second space; 310. Housing; 311. First through hole; 312. Second through hole; 313. Fourth through hole; 320. First seal; 321. Bolt; 330. Moving plug; 331. Groove; 332. First moving plate; 333. Third through hole; 334. Second moving plate; 340. Pull rod; 350. Second seal; 360. Third seal; 410. First connector; 420. Second connector; 50. Connecting ring. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0032] The battery manufacturing process includes electrolyte injection, wetting, formation, aging, capacity testing, and precision sealing. During wetting, formation, aging, and capacity testing, the battery generates gas, which needs to be discharged in a timely manner using an exhaust device 30.

[0033] In the prior art, the gas generated by the cell 20 is vented by connecting the vent valve to the sealing point of the aluminum-plastic film 10. However, the efficiency of venting the cell 20 by using the vent valve is low, which affects the battery assembly efficiency.

[0034] To address the aforementioned technical problems, the present invention provides a battery capable of timely venting.

[0035] A battery capable of timely venting according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0036] Specifically, such as Figures 1 to 3 As shown, an embodiment of the present invention provides a battery capable of timely venting, including an aluminum-plastic film 10, a venting device 30, and a battery cell 20 encapsulated in the aluminum-plastic film 10. The venting device 30 is used to vent the gas generated by the battery cell 20 out of the aluminum-plastic film 10. The aluminum-plastic film 10 is provided with a reserved opening 110, and the venting device 30 is connected to the reserved opening 110.

[0037] The exhaust device 30 includes a housing 310 and an exhaust assembly. The exhaust assembly is matched with the housing 310. One end of the housing 310 is provided with a plurality of first through holes 311. The plurality of first through holes 311 are connected to the inner cavity of the aluminum-plastic film 10. The gas generated by the battery cell 20 is discharged from the aluminum-plastic film 10 through the plurality of first through holes 311 under the action of the exhaust assembly.

[0038] In other words, the gas discharged from the cell 20 is discharged from the aluminum-plastic film 10 through the housing 310 via multiple first through holes 311 using the venting assembly. The venting assembly and multiple first through holes 311 enable timely and rapid gas discharge, greatly improving venting efficiency. According to the battery of this embodiment, the venting device 30 timely and efficiently discharges the gas generated by the cell 20, avoiding the use of DEGAS equipment, reducing the risk of corrosion caused by gas bag swelling attacking the aluminum-plastic film 10, and reducing the risk of electrode wrinkling and lithium plating caused by gas generation during formation, aging, and capacity testing. It is low-cost, highly operable, and highly safe.

[0039] In one embodiment, such as Figure 1 As shown, the housing 310 of the exhaust device 30 is located inside the aluminum-plastic film 10, and the exhaust assembly passes through the aluminum-plastic film 10 and matches the housing 310. When the housing 310 is located inside the aluminum-plastic film 10, the gas discharged from the battery cell 20 is discharged from the aluminum-plastic film 10 through multiple first through holes 311 and the housing 310 by pushing and pulling the exhaust assembly.

[0040] As an alternative embodiment, such as Figure 2 and Figure 3 As shown, the exhaust device 30 is located outside the aluminum-plastic film 10, and multiple first through holes 311 connect to the inner cavity of the aluminum-plastic film 10. The exhaust principle of the exhaust device 30 is the same whether it is located outside or inside the aluminum-plastic film 10; both exhaust the gas generated by the battery cell 20 through a push-pull exhaust assembly. The difference lies in the fact that the precision sealing of the housing 310 when it is inside the aluminum-plastic film 10 is later than the precision sealing of the housing 310 when it is outside the aluminum-plastic film 10. The volume of the aluminum-plastic film 10 required for assembly when the housing 310 is inside the aluminum-plastic film 10 is greater than the volume of the aluminum-plastic film 10 required for assembly when the housing 310 is outside the aluminum-plastic film 10.

[0041] Specifically, such as Figure 1 As shown, when the housing 310 is located inside the aluminum-plastic film 10, it is arranged adjacent to the battery cell 20, and the exhaust assembly is connected to the reserved port 110.

[0042] In other words, the housing 310 is located inside the aluminum-plastic film 10, and the exhaust assembly is sealed to the reserved port 110. The exhaust assembly is inserted from the reserved port 110 into the aluminum-plastic film 10 and matches the housing 310 so that the gas generated by the battery cell 20 is discharged from the aluminum-plastic film 10 through the first through hole 311 via the exhaust assembly.

[0043] In one embodiment, the outer diameter of the housing 310 is 5mm to 20mm. More preferably, the outer diameter of the housing 310 is 8mm to 14mm. A diameter greater than 14mm places strict requirements on the punching capability of the aluminum-plastic film 10 during the assembly process, making it difficult to process and prone to wrinkles at the sealing area of ​​the aluminum-plastic film 10 and wrinkles on the aluminum-plastic film 10 of the battery cell 20 body, affecting the appearance of the finished battery cell 20. If the outer diameter of the housing 310 is less than 8mm, the exhaust device 30 is prone to deformation, and the exhaust component is prone to jamming, which can easily cause the exhaust component to be difficult to push and pull, and cause the aluminum-plastic film 10 to be twisted.

[0044] In one embodiment, the distance between the housing 310 and the battery cell 20 is 10mm to 30mm. A distance of less than 10mm between the housing 310 and the battery cell 20, meaning they are close together, makes it inconvenient to fix the positions of the battery cell 20 and the housing 310. Conversely, a greater distance significantly increases the amount of aluminum-plastic film 10 used.

[0045] In one embodiment, the aluminum-plastic film 10 is provided with a plurality of fixing points 120, and the plurality of fixing points 120 are located at the bottom of the exhaust device 30.

[0046] In other words, by dot-sealing the aluminum-plastic film 10 to form a fixed point 120, the position of the battery cell 20 and the exhaust device 30 within the aluminum-plastic film 10 is limited, thus preventing the battery cell 20 and the exhaust device 30 from slipping.

[0047] In one embodiment, the battery capable of timely venting further includes a connecting ring 50, which is sealed within the pre-reserved opening 110. The outer wall of the connecting ring 50 is made of the same material as the inner wall of the pre-reserved opening 110. The connecting ring 50 is used to improve the sealing effect between the venting assembly and the pre-reserved opening 110. Both the outer wall of the connecting ring 50 and the inner wall of the pre-reserved opening 110 are made of PP material, and the thickness of the PP adhesive on the outer wall of the connecting ring 50 is 0.5 mm to 2 mm. At a temperature of 170° to 200°C, the outer wall of the connecting ring 50 and the inner wall of the pre-reserved opening 110 have good compatibility, forming a good encapsulation seal.

[0048] Furthermore, the connecting ring 50 includes at least one corrosion-resistant rubber sealing ring, and the exhaust assembly can also achieve a sealing effect during the push-pull movement.

[0049] This invention also provides a method for assembling the battery cell 20 and the exhaust device 30 when the housing 310 is located inside the aluminum-plastic film 10, including:

[0050] The aluminum-plastic film 10 is perforated using a perforation die to form the battery cell 20 slot, the venting device 30 slot, and the connecting ring 50 slot. The perforation thickness of the battery cell 20 slot is consistent with the thickness of the battery cell 20; the perforation thickness of the venting device 30 slot is consistent with the outer diameter or thickness of the venting device 30; and the perforation thickness of the connecting ring 50 slot is consistent with the thickness or diameter of the connecting ring 50. This significantly reduces wrinkles on the surface of the aluminum-plastic film 10.

[0051] The cell 20 is placed in the cell 20 pit and the first packaging is performed. The packaging includes positive and negative tab packaging, bottom sealing and spot sealing.

[0052] After the first sealing is completed, the exhaust device 30 is installed into the exhaust device 30 slot and the position of the connecting ring 50 is adjusted for the second sealing.

[0053] The battery cell 20 and the venting device 30 are assembled and sealed sequentially to prevent wrinkles in the aluminum-plastic film 10 during sealing. Furthermore, the battery cell 20 and the venting device 30 are sealed separately to prevent slippage of the venting device 30 and improve the venting effect of the battery.

[0054] like Figure 2 and Figure 3 As shown, when the exhaust device 30 is located outside the aluminum-plastic film 10, the plurality of first through holes 311 are connected to the reserved opening 110; the exhaust device 30 also includes a support member (not shown in the figure), which is connected to the lower surface of the housing 310.

[0055] In other words, one end of the venting device 30 is connected to the aluminum-plastic film 10, and the venting device 30 is supported by a support member. The venting principle of the venting device 30 in this embodiment of the invention is the same as that of the venting device 30 located inside the aluminum-plastic film 10 in the housing 310. In the battery assembly process of this embodiment of the invention, it is not necessary to punch the venting device 30 slot on the aluminum-plastic film 10, and the battery can be precisely sealed earlier. In addition, the size of the venting device 30 is not limited and can be adjusted according to the size of the battery.

[0056] In one embodiment, when the venting device 30 is located outside the aluminum-plastic film 10, the battery capable of timely venting also includes a connector. The connector includes a first connector 410 and a second connector 420. The first connector 410 matches the second connector 420. The first connector 410 is connected to the reserved opening 110, and the second connector 420 is connected to the end of the housing 310. Preferably, the end of the housing 310 extends to form the second connector 420, improving the sealing effect between the second connector 420 and the housing 310. The second connector 420 and the first connector 410 are preferably tapered, and both are made of magnetic metal to improve the connection efficiency and sealing effect of the first connector 410 and the second connector 420.

[0057] In one embodiment, such as Figure 4 and Figure 5As shown, the exhaust assembly includes a first seal 320, a moving plug 330, and a pull rod 340. The first seal 320 is connected to the inner end of the housing 310 and can form a seal with a plurality of first through holes 311. The moving plug 330 is connected to the pull rod 340 and divides the housing 310 into a first space 30a and a second space 30b. The moving plug 330 moves within the housing 310 under the action of the pull rod 340 to exhaust the gas discharged by the battery cell 20 into the first space 30a and then through the moving plug 330 before being discharged.

[0058] In other words, the gas in the aluminum-plastic film 10 is discharged from the moving plug 330 and the pull rod 340 by the pull rod 340 doing work. That is, the pull rod 340 does mechanical movement. The pull rod 340 can be connected to external mechanical equipment to drive it to do mechanical movement, so that the gas in the aluminum-plastic film 10 is discharged through the exhaust assembly to form an airflow.

[0059] In one embodiment, the first seal 320 is connected to the end of the housing by bolts 321, that is, the first seal 320 can move after being subjected to force. When the first seal 320 is subjected to greater pressure inside the aluminum-plastic film, the first seal 320 separates from the multiple first through holes and is in an open or closed state; when the first seal 320 is subjected to greater pressure inside the housing, the first seal 320 forms a seal with the multiple first through holes.

[0060] Furthermore, the exhaust assembly also includes an exhaust channel that connects the first space 30a, the moving plug 330, and the pull rod 340.

[0061] like Figure 4 As shown, the interior of the pull rod 340 is hollow and forms an exhaust channel with the channel in the moving plug 330. The interior of the pull rod 340 is connected to the outside of the aluminum-plastic film 10 to discharge gas.

[0062] Furthermore, the exhaust assembly also includes a second seal 350, which matches the inner cavity of the housing 310. The moving plug 330 has a groove 331, and the second seal 350 is located in the groove 331. When the exhaust assembly moves toward the first through hole 311, the gas in the first space 30a flows into the exhaust channel and is discharged. The second seal 350 is preferably a sealing ring, but it is not limited to this.

[0063] In one embodiment, the exhaust assembly further includes a third seal 360 connected to the pull rod 340 for sealing the inner cavity of the pull rod 340 with the outside.

[0064] In one embodiment, the moving plug 330 includes a first moving plate 332 and a second moving plate 334. The first moving plate 332 is connected to the second moving plate 334, and both the first moving plate 332 and the second moving plate 334 are matched with the inner cavity of the housing 310. The groove 331 is formed between the first moving plate 332 and the second moving plate 334, and the bottom end of the groove 331 is provided with a third through hole 333.

[0065] Specifically, such as Figure 4 As shown, the pull rod 340 moves along the s1 direction. The second seal 350, blocked by the second moving plate 334, forms a seal between the second moving plate 334 and the housing 310, i.e., a seal between the second moving plate 334 and the second space 30b. The first seal 320 also forms a seal with the housing 310. Gas in the first space 30a flows into the groove 331 through the gap between the first moving plate 332 and the housing 310, and flows through the third through hole 333 to the interior of the pull rod 340, i.e., the gas is discharged from the aluminum-plastic film 10 through the exhaust channel. (Refer to...) Figure 4 The arrows indicate the direction of gas flow within the exhaust channel.

[0066] like Figure 5 As shown, the pull rod 340 moves along the s2 direction. The second seal 350, blocked by the first moving plate 332, forms a seal between the first moving plate 332 and the housing 310, that is, a seal is formed between the first space 30a and the first moving plate 332. The negative pressure in the aluminum-plastic film 10 keeps the first seal 320 and the housing 310 in an open state, meaning that the gas in the aluminum-plastic film 10 flows from the first through hole 311 to the first space 30a.

[0067] Figure 4 and Figure 5 This diagram illustrates two states in which the pull rod 340 moves along directions s1 and s2, respectively. In this embodiment of the invention, the gas in the aluminum-plastic film 10 is drawn into the housing 310 and then discharged by pushing and pulling the pull rod 340.

[0068] The exhaust device 30 provided in this embodiment of the invention can change the rate of gas discharge by changing the frequency of pushing and pulling the lever 340, thereby effectively and timely discharging excess gas. In addition, the exhaust device 30 has a simple structure, good sealing effect, is not easy to clog, does not easily cause electrolyte to be extracted, and can be reused, which greatly improves the process pass rate, operability and safety.

[0069] like Figure 6 and Figure 7 As shown, Figure 6 This is a schematic diagram of the structure at the end of the housing 310. The end of the housing 310 is provided with multiple first through holes 311. Figure 7The diagram shows the structure of the other end of the housing 310. The other end of the housing 310 is provided with multiple second through holes 312 for air intake and exhaust, and a fourth through hole 313 in the middle for accommodating the pull rod 340.

[0070] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A battery capable of timely venting, characterized in that, The system includes an aluminum-plastic film, an exhaust device, and a battery cell encapsulated within the aluminum-plastic film. The exhaust device is used to discharge gas generated by the battery cell from the aluminum-plastic film. The aluminum-plastic film has a pre-drilled opening, and the exhaust device is connected to the pre-drilled opening. The exhaust device includes a housing and an exhaust assembly, the exhaust assembly being matched with the housing, and one end of the housing having a plurality of first through holes, the plurality of first through holes communicating with the inner cavity of the aluminum-plastic film; The exhaust assembly includes a first seal, a moving plug, and a pull rod. The first seal is connected to the inner end of the housing and can form a seal with multiple first through holes. The moving plug is connected to the pull rod and divides the housing into a first space and a second space. The moving plug moves within the housing under the action of the pull rod to exhaust the gas discharged from the battery cell into the first space through multiple first through holes. The exhaust assembly further includes an exhaust channel that connects the first space, the moving plug, and the pull rod. The exhaust assembly further includes a second seal that matches the inner cavity of the housing. The moving plug has a groove, and the second seal is located in the groove. When the exhaust assembly moves toward the first through hole, the gas in the first space flows into the exhaust channel and is discharged from the aluminum-plastic film.

2. The battery capable of timely venting as described in claim 1, characterized in that, The housing is located inside the aluminum-plastic film and is arranged adjacent to the battery cell, and the exhaust assembly is connected to the reserved port.

3. The battery capable of timely venting as described in claim 2, characterized in that, The outer diameter of the shell is 5mm to 20mm.

4. The battery capable of timely venting as described in claim 2, characterized in that, The distance between the casing and the battery cell is 10mm to 30mm.

5. The battery capable of timely venting as described in claim 2, characterized in that, The aluminum-plastic film has multiple fixing points, which are located at the bottom of the exhaust device.

6. The battery capable of timely venting as described in claim 1, characterized in that, The exhaust device is located outside the aluminum-plastic film, and multiple first through holes are connected to the reserved opening; The exhaust device also includes a support member connected to the lower surface of the housing.

7. The battery capable of timely venting as described in claim 1, characterized in that, It also includes a connecting ring, which is sealed and connected to the reserved opening, and the outer wall of the connecting ring is made of the same material as the inner wall of the reserved opening.

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