A soft-pack battery compression venting device

Abstract

This utility model discloses a pouch battery compression venting device, comprising: a housing and a venting assembly. The housing has an internal compression groove for accommodating the pouch battery and an opening communicating with the compression groove. The compression groove includes a first cavity, a second cavity, and a third cavity arranged sequentially from the inside to the outside and communicating with each other along the direction near the opening. The venting assembly is built into the first cavity, the second cavity, and the third cavity and is movably connected to the housing. The venting assembly can sequentially reduce the volume of the first cavity, the second cavity, and the third cavity, and abut against the pouch battery to vent the gas inside the pouch battery. This utility model effectively solves the problem that when the rubber plate contacts the battery surface, it cannot promote the upward movement and overflow of gas generated at the bottom of the battery, thus preventing the gas from being effectively vented.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery production technology, specifically to a soft-pack battery extrusion and degassing device. Background Technology

[0002] In the production of lithium batteries, it is necessary to remove the gas produced during the formation process. The clamping formation method is usually adopted, which involves using two parallel clamps to clamp the battery during the formation process and squeezing the gas generated inside into a gas bag.

[0003] For example, Chinese utility model patent CN209001042U, entitled "A Lithium-ion Battery Inflating and Pressurizing Formation Device," includes multiple flat plates whose distance is adjusted by a drive component, forming a battery clamping space between adjacent plates; a rubber plate fixed to one side of the flat plates; air grooves formed in the rubber plates, filled with fluid, and the rubber plates expand inwards through the fluid; after the flat plates clamp the battery, the battery is in contact with the expanded rubber plate; air holes are provided on the flat plates, and an external fluid supply device communicates with the air grooves of the rubber plates through the air holes. This device uses the method of inflating the rubber plates to pressurize the battery. The rubber plates automatically deform under pressure according to the unevenness of the battery surface, ensuring uniform pressure on all points on the battery surface during clamping and pressurization, improving the performance of the battery after formation, and thus improving the performance of the battery product.

[0004] However, during the venting process, the flat surface of the rubber plate is in contact with the battery surface at the same time, which cannot promote the gas generated at the bottom of the battery to actively move upward and overflow, thus causing the gas to be unable to be effectively vented. Utility Model Content

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose a soft-pack battery extrusion and exhaust device to solve the technical problem in the prior art that the gas generated at the bottom of the battery cannot be effectively discharged because the rubber plate cannot promote the gas generated at the bottom of the battery to move upward and overflow when it comes into contact with the battery surface.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: This utility model provides a soft-pack battery compression and degassing device, comprising: The housing has an internal compression groove for accommodating a pouch battery and an opening communicating with the compression groove. The compression groove includes a first cavity, a second cavity, and a third cavity arranged sequentially from the inside to the outside and communicating with each other along a direction close to the opening; and An exhaust assembly is built into the first cavity, the second cavity, and the third cavity, and is movably connected to the housing. The exhaust assembly can sequentially reduce the volume of the first cavity, the second cavity, and the third cavity, and abuts against the soft-pack battery to vent the gas inside the soft-pack battery.

[0007] In some embodiments, the exhaust assembly includes two first exhaust members, two second exhaust members, and two third exhaust members. The two first exhaust members are arranged opposite to each other and are movably built into the first cavity. The two second exhaust members are arranged opposite to each other and are movably built into the second cavity. The two third exhaust members are arranged opposite to each other and are movably built into the third cavity. The two first exhaust members, the two second exhaust members, and the two third exhaust members can sequentially abut against the pouch battery.

[0008] In some embodiments, the first, second, and third exhaust members located on the same sidewall of the extrusion groove can abut against each other.

[0009] In some embodiments, the first exhaust component includes a rubber airbag connected to the inner wall of the extrusion groove and capable of abutting against the outer wall of the pouch battery, and the interior of the rubber airbag is connected to an external air supply device.

[0010] In some embodiments, the first exhaust component further includes a silicone coating that uniformly covers the surface of the rubber airbag and is able to abut against the outer wall of the pouch battery.

[0011] In some embodiments, the soft-pack battery extrusion venting device further includes four partitions, the four partitions being in pairs, the two pairs of partitions being spaced apart from each other and respectively connected to the inner walls of the two pairs of extrusion grooves, and the partitions being disposed between the first cavity and the second cavity or between the second cavity and the third cavity.

[0012] In some embodiments, the partition is a rigid structure.

[0013] In some embodiments, the soft-pack battery extrusion venting device further includes a plurality of connectors, which are disposed at the connection between the inner wall of the extrusion groove and the partition, and are connected to both the inner wall of the extrusion groove and the partition.

[0014] In some embodiments, the connector is triangular in shape, and the cross-sectional area of ​​the connector gradually decreases along the direction close to the pouch battery.

[0015] In some embodiments, the pouch battery extrusion venting device further includes a fixing bracket connected to the bottom inner wall of the extrusion groove and having a slot in which the pouch battery is inserted.

[0016] Compared with the prior art, the beneficial effects of the soft-pack battery compression venting device provided by this utility model include: a compression groove for accommodating the soft-pack battery is formed inside the housing, and the compression groove includes a first cavity, a second cavity and a third cavity arranged sequentially from the inside to the outside and interconnected with each other along the direction close to the opening; the venting component is movably built into the first cavity, the second cavity and the third cavity; the venting component can sequentially reduce the volume of the first cavity, the second cavity and the third cavity and abut against the soft-pack battery to vent the gas inside the soft-pack battery. Compared to existing technologies, by dividing the extrusion groove into three different chambers and utilizing the venting assembly dynamically integrated into the extrusion groove, the volume of the three chambers can be reduced sequentially from the inside out, thereby forming a sequential extrusion of the pouch battery from bottom to top. This promotes the active upward movement and overflow of gas generated at the bottom of the battery, effectively venting the gas inside the pouch battery, efficiently eliminating air bubbles between the electrodes, reducing defects such as purple spots, lithium plating, and air bubbles, and improving the overall performance of the battery. This solves the technical problem in existing technologies where the rubber plate cannot promote the active upward movement and overflow of gas generated at the bottom of the battery when in contact with the battery surface, resulting in the ineffective exhaust of gas. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of a soft-pack battery compression venting device connected to a soft-pack battery, according to an embodiment of this utility model. Figure 2 This is a cross-sectional view of the connection between the shell, the partition, and the connecting body provided in one embodiment of the present invention; Figure 3 This is a cross-sectional view of the first exhaust component provided in an embodiment of the present invention; Figure 4 This is a cross-sectional view of a soft-pack battery compression venting device connected to a soft-pack battery in another state, according to an embodiment of this utility model.

[0018] Explanation of reference numerals in the attached figures: Housing 100; First cavity 110; Second cavity 120; Third cavity 130; Exhaust assembly 200; First exhaust component 210; Rubber airbag 211; Silicone coating 212; Second exhaust component 220; Third exhaust component 230; Partition 300; Connector 400; Fixing bracket 500; Soft-pack battery 600. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0020] To address the technical problem that the rubber sheet cannot effectively expel gas generated at the bottom of the battery when in contact with the battery surface, thus preventing the gas from actively moving upwards and overflowing, this invention provides a soft-pack battery compression venting device. This device divides the compression groove into three different chambers, and utilizes a venting component 200 movably integrated into the compression groove to sequentially reduce the volume of the three chambers from the inside out. This creates a bottom-up compression effect on the soft-pack battery 600, promoting the active upward movement and overflow of gas generated at the bottom of the battery. This effectively vents the gas inside the soft-pack battery 600, efficiently removes air bubbles between the electrodes, reduces defects such as purple spots, lithium plating, and air bubbles, and improves the overall performance of the battery.

[0021] Please see Figure 1 , Figure 4 , Figures 1 to 3 This is a schematic diagram of the structure of a soft-pack battery compression venting device according to an embodiment of the present invention. The soft-pack battery compression venting device includes: a housing 100 and a venting assembly 200. The housing 100 has a compression groove for accommodating a soft-pack battery 600 and an opening connected to the compression groove. The compression groove includes a first cavity 110, a second cavity 120 and a third cavity 130 arranged sequentially from the inside to the outside and connected to each other along the direction close to the opening. The venting assembly 200 is built into the first cavity 110, the second cavity 120 and the third cavity 130 and is movably connected to the housing 100. The venting assembly 200 can sequentially reduce the volume of the first cavity 110, the second cavity 120 and the third cavity 130 and abut against the soft-pack battery 600 to vent the gas inside the soft-pack battery 600.

[0022] In this device, compared to existing technologies, by dividing the extrusion groove into three different cavities and utilizing the exhaust assembly 200 movably built into the extrusion groove, the volume of the three cavities can be reduced sequentially from the inside out, thereby forming a sequential extrusion of the soft-pack battery 600 from bottom to top. This promotes the active upward movement and overflow of gas generated at the bottom of the battery, effectively venting the gas inside the soft-pack battery 600, efficiently eliminating air bubbles between the electrodes, reducing defects such as purple spots, lithium plating, and air bubbles, and improving the overall performance of the battery. This solves the technical problem in existing technologies where the rubber plate cannot promote the active upward movement and overflow of gas generated at the bottom of the battery when in contact with the battery surface, resulting in the ineffective exhaust of gas.

[0023] Furthermore, in the battery manufacturing process, the formation process is the most critical step. During formation, an SEI film (also known as an interface film, which is a passivation layer formed on the surface of the electrode material during the first charge and discharge of a liquid lithium-ion battery, where the electrode material and electrolyte react at the solid-liquid interface) is formed. This not only effectively stabilizes the negative electrode interface but also prevents excessive side reactions between the electrolyte and the negative electrode. The quality of the SEI film affects the battery's cycle life, stability, self-discharge, safety, and other electrochemical performance. Because the formation process involves the initial reaction between the fresh electrolyte and the negative electrode, a large amount of gas is generated. If this gas is not effectively removed, small bubbles will form between the electrode and the separator, hindering the migration of lithium ions between the positive and negative electrodes. This can lead to problems such as lithium plating during charging, increased internal resistance, purple spots at the interface, and shortened battery life. Therefore, removing the gas generated during the formation process has a significant impact on the performance of the lithium battery. This is a standard practice known to those skilled in the art and will not be elaborated further here.

[0024] In some embodiments, the housing 100 is provided with a plurality of extrusion grooves and a plurality of openings, and the plurality of extrusion grooves are arranged sequentially at intervals along the length of the housing 100, and the openings are arranged in a one-to-one correspondence with the extrusion grooves and are connected to each other, which will not be described in detail here.

[0025] In this embodiment, the exhaust assembly 200 includes two first exhaust components 210, two second exhaust components 220, and two third exhaust components 230. The two first exhaust components 210 are arranged opposite to each other and are movably built into the first cavity 110. The two second exhaust components 220 are arranged opposite to each other and are movably built into the second cavity 120. The two third exhaust components 230 are arranged opposite to each other and are movably built into the third cavity 130. The two first exhaust components 210, the two second exhaust components 220, and the two third exhaust components 230 can sequentially abut against the soft-pack battery 600.

[0026] Two first exhaust components 210 are movably built into the first cavity 110 to squeeze the soft-pack battery 600 from both sides. Two second exhaust components 220 are movably built into the second cavity 120 to squeeze the soft-pack battery 600 from both sides. Two third exhaust components 230 are movably built into the third cavity 130 to squeeze the soft-pack battery 600 from both sides. This can effectively promote the upward movement of gas from the bottom and its eventual overflow.

[0027] Furthermore, the first exhaust component 210, the second exhaust component 220, and the third exhaust component 230 can be rubber plates driven by linear drive components. The linear drive components can be cylinders, hydraulic cylinders, push rod motors, etc. For reference, please refer to the Chinese utility model patent with publication number CN209001042U, entitled "A Lithium-ion Battery Gas-pressurizing Formation Device", which will not be elaborated here.

[0028] In one embodiment, please refer to Figure 4 The first exhaust member 210, the second exhaust member 220 and the third exhaust member 230 located on the same side wall of the extrusion groove can abut against each other.

[0029] By using the first exhaust member 210, the second exhaust member 220, and the third exhaust member 230 respectively to reduce the volume of the first cavity 110, the second cavity 120, and the third cavity 130, the first exhaust member 210, the second exhaust member 220, and the third exhaust member 230 abut against each other, which can cause all side surfaces of the soft-pack battery 600 to be squeezed, effectively promoting the complete discharge of gas.

[0030] Furthermore, the second exhaust component 220 can be partially stacked on the first exhaust component 210, and similarly, the third exhaust component 230 can be partially stacked on the second exhaust component 220, thereby effectively promoting the complete exhaust of gas.

[0031] In one embodiment, please refer to Figure 3 , 4 The first exhaust component 210 includes a rubber airbag 211, which is connected to the inner wall of the extrusion groove and can abut against the outer wall of the soft-pack battery 600. The interior of the rubber airbag 211 is connected to an external air supply device.

[0032] By supplying air into the airbag using an external air supply device, the volume of the airbag can be increased and the volume of the first cavity 110 can be gradually reduced. When the airbag comes into contact with the outer surface of the soft-pack battery 600, the airbag applies a squeezing force to the soft-pack battery 600, thereby squeezing out the gas inside the soft-pack battery 600.

[0033] Furthermore, the airbag is made of fluorinated rubber, which has high elasticity, excellent tensile strength, good heat resistance, and resistance to organic solvent corrosion, resulting in more stable performance. Alternatively, commonly available and readily procurable materials such as silicone rubber, neoprene rubber, and butyl rubber can also be used. This is a conventional design known to those skilled in the art and will not be elaborated upon here.

[0034] In one embodiment, please refer to Figure 3 , 4 The first exhaust component 210 also includes a silicone coating 212, which uniformly covers the surface of the rubber airbag 211 and can abut against the outer wall of the soft-pack battery 600.

[0035] To increase the fit between the airbag and the soft-pack battery 600, the outer surface of the airbag is uniformly coated with a silicone coating 212. Silicone rubber is soft and has a large deformation capacity, allowing it to fit completely with flat or uneven areas of the battery surface, achieving uniform compression of the battery. This does not damage the battery's appearance.

[0036] Furthermore, the silicone coating 212 here is made of materials such as nitrile rubber, styrene-butadiene rubber, and polyurethane, which are conventional settings known to those skilled in the art and will not be described in detail here.

[0037] In some embodiments, the second exhaust component 220 and the third exhaust component 230 are respectively composed of an airbag and a silicone coating 212.

[0038] Furthermore, the sizes of the rubber airbags 211 located in the first cavity 110, the second cavity 120, and the third cavity 130 are all different and can be adjusted according to specific production conditions, which will not be elaborated here.

[0039] In one embodiment, please refer to Figure 1 , Figure 4 The soft-pack battery extrusion and degassing device also includes four partitions 300. The four partitions 300 are arranged in pairs, and the two pairs of partitions 300 are spaced apart from each other and connected to the inner walls of the two sides of the extrusion groove respectively. The partitions 300 are located between the first cavity 110 and the second cavity 120 or between the second cavity 120 and the third cavity 130.

[0040] In order to guide the rubber airbag 211 to increase in volume along a specified path to control the squeezing pressure and avoid interference between two adjacent rubber airbags 211, a partition 300 is provided between the first cavity 110 and the second cavity 120 or between the second cavity 120 and the third cavity 130.

[0041] In some embodiments, the length of the separator 300 is approximately half the distance between the outer wall of the pouch cell 600 and the interior of the extrusion groove.

[0042] In one embodiment, the partition 300 is a rigid structure.

[0043] The rigid structure design of the partition 300 can improve the stability of the device operation and meet the requirements of repeated use.

[0044] Furthermore, the material of the partition 300 can be a common and readily available hard plastic or the same material as the shell 100, which will not be elaborated here.

[0045] In one embodiment, such as Figure 2As shown, the soft-pack battery extrusion venting device also includes multiple connectors 400. The connectors 400 are disposed at the connection between the inner wall of the extrusion groove and the partition 300, and are connected to both the inner wall of the extrusion groove and the partition 300.

[0046] In order to increase the connection strength between the partition 300 and the housing 100 and improve the stability of the device operation, the connector 400 is provided at the connection between the inner wall of the extrusion groove and the partition 300, and is connected to both the inner wall of the extrusion groove and the partition 300.

[0047] In addition, in some embodiments, in order to increase the connection stability between the partition 300 and the inner wall of the housing 100, a connector 400 is provided on both sides of the partition 300.

[0048] In one embodiment, such as Figure 2 As shown, the connector 400 is triangular, and the cross-sectional area of ​​the connector 400 gradually decreases along the direction close to the soft-pack battery 600.

[0049] By setting the cross-sectional area of ​​the connector 400 to gradually decrease along the direction close to the soft-pack battery 600, the influence of the connector 400 on the movement trajectory of the rubber airbag 211 can be effectively avoided.

[0050] In this embodiment, as Figure 1 , Figure 4 As shown, the soft-pack battery extrusion and degassing device also includes a fixed bracket 500, which is connected to the bottom inner wall of the extrusion groove and has a slot in which the soft-pack battery 600 is inserted.

[0051] By setting a fixed bracket 500 at the center of the bottom inner wall of the extrusion groove, the soft-pack battery 600 can be fixed, preventing the soft-pack battery 600 from shifting during the extrusion process and improving the stability of the device operation.

[0052] Furthermore, the mounting bracket 500 here has a slot, and the slot is also provided with an elastic pad, which can hold the pouch battery 600 in the slot to improve the stability of the pouch battery 600 connection.

[0053] To better understand this utility model, the following is combined with... Figures 1 to 4 The technical solution of this utility model is described in detail below: The housing 100 has a compression groove inside to accommodate the pouch battery 600. The compression groove includes a first cavity 110, a second cavity 120 and a third cavity 130 arranged sequentially from the inside to the outside and interconnected with each other along the direction close to the opening. The exhaust assembly 200 is movably built into the first cavity 110, the second cavity 120 and the third cavity 130. The exhaust assembly 200 can sequentially reduce the volume of the first cavity 110, the second cavity 120 and the third cavity 130 and abut against the pouch battery 600 to vent the gas inside the pouch battery 600. Compared to existing technologies, by dividing the extrusion groove into three different cavities and utilizing the venting assembly 200 which is movably built into the extrusion groove, the volume of the three cavities can be reduced sequentially from the inside out, thereby forming a sequential extrusion of the soft-pack battery 600 from bottom to top. This promotes the active upward movement and overflow of gas generated at the bottom of the battery, effectively venting the gas inside the soft-pack battery 600, efficiently eliminating air bubbles between the electrodes, reducing defects such as purple spots, lithium plating, and air bubbles, and improving the overall performance of the battery.

[0054] The specific working process of this utility model is as follows: First, the battery after liquid injection and sealing is placed on the fixed bracket 500 and charged with a current of 0.1C to start the formation. Then, 0.2MPa air pressure is injected into the three rubber air bags 211 located in the first cavity 110, the second cavity 120 and the third cavity 130 respectively. At this time, the rubber air bags 211 expand, start to contact the battery surface and apply pressure to the battery. Next, the pressure of the rubber airbag 211 in the first cavity 110 is increased to 0.4 MPa, while the pressure of the rubber airbags 211 in the second cavity 120 and the third cavity 130 is maintained at 0.2 MPa for 10 minutes. At this time, the air bubbles between the electrodes at the bottom of the battery (near the rubber airbag 211 in the first cavity 110) escape to the upper part of the battery due to the pressure difference. Subsequently, the pressure of the rubber airbag 211 in the second cavity 120 is increased to 0.4 MPa, while the pressure of the rubber airbags 211 in the third cavity 130 is maintained at 0.2 MPa for 10 minutes. The pressure in the rubber airbag 211 inside is maintained at 0.2 MPa for 10 minutes. At this time, the air bubbles between the electrodes in the middle of the battery (near the rubber airbag 211 in the second cavity 120) escape to the upper part of the battery due to the pressure difference. Then, the pressure in the rubber airbag 211 in the third cavity 130 is increased to 0.4 MPa for 10 minutes. At this time, the gas in the upper part of the battery (near the rubber airbag 211 in the third cavity 130) escapes collectively into the upper air bag, completing one complete exhaust cycle. Then, the pressure of the three rubber airbags 211 located in the first cavity 110, the second cavity 120 and the third cavity 130 respectively is collectively reduced to 0.2MPa. Due to the reduction in pressure on the battery, a slight rebound will occur in the thickness direction of the battery, which will cause the previously squeezed-out electrolyte to be reabsorbed and wetted into the pores of the electrode and the separator, further promoting the full reaction of the formation process.

[0055] Finally, the above extrusion steps are repeated several times to allow the gas generated inside the battery to be circulated out, while the electrolyte is fully soaked and reacts until the formation process is completed.

[0056] This application, through the aforementioned structure, can solve the technical problem in the prior art where the gas generated at the bottom of the battery cannot be effectively discharged because the rubber plate cannot promote the active upward movement and overflow of the gas when it comes into contact with the battery surface.

[0057] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A pouch battery compression venting device, characterized in that, include: The housing has an internal compression groove for accommodating a pouch battery and an opening communicating with the compression groove. The compression groove includes a first cavity, a second cavity, and a third cavity arranged sequentially from the inside to the outside and communicating with each other along a direction close to the opening; and An exhaust assembly is built into the first cavity, the second cavity, and the third cavity, and is movably connected to the housing. The exhaust assembly can sequentially reduce the volume of the first cavity, the second cavity, and the third cavity, and abuts against the soft-pack battery to vent the gas inside the soft-pack battery.

2. The soft-pack battery extrusion and degassing device according to claim 1, characterized in that, The exhaust assembly includes two first exhaust components, two second exhaust components, and two third exhaust components. The two first exhaust components are arranged opposite to each other and are movably built into the first cavity. The two second exhaust components are arranged opposite to each other and are movably built into the second cavity. The two third exhaust components are arranged opposite to each other and are movably built into the third cavity. The two first exhaust components, the two second exhaust components, and the two third exhaust components can sequentially abut against the soft-pack battery.

3. The soft-pack battery extrusion and degassing device according to claim 2, characterized in that, The first, second, and third exhaust components located on the same sidewall of the extrusion groove can abut against each other.

4. The soft-pack battery extrusion and degassing device according to claim 2, characterized in that, The first exhaust component includes a rubber airbag, which is connected to the inner wall of the extrusion groove and can abut against the outer wall of the soft-pack battery. The interior of the rubber airbag is connected to an external air supply device.

5. The soft-pack battery extrusion venting device according to claim 4, characterized in that, The first exhaust component also includes a silicone coating, which uniformly covers the surface of the rubber airbag and can abut against the outer wall of the soft-pack battery.

6. The soft-pack battery extrusion venting device according to claim 2, characterized in that, The soft-pack battery extrusion and degassing device also includes four partitions, which are arranged in pairs. The two pairs of partitions are spaced apart from each other and are respectively connected to the inner walls of the two pairs of extrusion grooves. The partitions are located between the first cavity and the second cavity or between the second cavity and the third cavity.

7. The soft-pack battery extrusion venting device according to claim 6, characterized in that, The partition is a rigid structure.

8. The soft-pack battery extrusion venting device according to claim 7, characterized in that, The soft-pack battery extrusion venting device also includes multiple connectors, which are disposed at the connection between the inner wall of the extrusion groove and the partition, and are connected to both the inner wall of the extrusion groove and the partition.

9. The soft-pack battery extrusion venting device according to claim 8, characterized in that, The connector is triangular in shape, and its cross-sectional area gradually decreases along the direction closest to the pouch battery.

10. The soft-pack battery extrusion venting device according to claim 1, characterized in that, The soft-pack battery extrusion and degassing device also includes a fixed bracket, which is connected to the bottom inner wall of the extrusion groove and has a slot in which the soft-pack battery is inserted.

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