Soft package lithium ion battery airtightness full detection gas bag

Abstract

The utility model relates to soft package battery packaging technical field, specifically disclose a soft package lithium ion battery air tightness full detection gas bag, including gas bag and install in the gas bag one side angle's gas detection block, the gas detection block heat seals in the gas bag, the inside of gas detection block is communicated with the inner chamber of gas bag through diffusion hole, and the gas inlet and outlet of gas detection block are provided with the sealing rubber cap of interference fit. The utility model carries out twice helium leak detection air tightness full detection to soft package lithium ion battery through the encapsulation of gas detection block in the one side angle of gas bag, improves the liquid leakage risk of soft package lithium ion battery in the production and use process, sets up the diffusion hole of diffusion shape simultaneously in the through hole of gas detection block, makes the electrolyte in the liquid injection process inhale the inside of soft package lithium ion battery in diffusion shape, improves the pole piece infiltration effect.

Description

Technical Field

[0001] This utility model relates to the field of soft-pack battery packaging technology, and in particular to a soft-pack lithium-ion battery airtightness full inspection air bag. Background Technology

[0002] Currently, lithium-ion batteries mainly include three structures: cylindrical, prismatic, and pouch. Pouch batteries are widely used due to their high dimensional flexibility and low unit cost. However, because pouch batteries do not have a complete metal outer casing like cylindrical and prismatic batteries, they are more prone to electrolyte leakage during production and use. Lithium-ion battery electrolytes are usually toxic and harmful to human health. Furthermore, electrolytes are often flammable and explosive, posing a high risk of combustion and explosion after leakage.

[0003] Currently, in the production process of pouch batteries, the sealing effect is typically judged only by measuring the thickness of the encapsulated area and conducting tensile tests. However, due to limitations in manpower and the fact that tensile testing is a destructive test, these methods are usually used for random sampling during the production process, resulting in low reliability and failing to accurately reflect the airtightness reliability of the pouch battery encapsulation. Therefore, this patent designs a pouch lithium-ion battery airtightness full inspection airbag to perform a full airtightness inspection after the pouch lithium-ion battery is encapsulated, thereby addressing the risk of leakage in pouch lithium-ion batteries. Utility Model Content

[0004] The purpose of this invention is to provide a gas bag for full inspection of the airtightness of soft-pack lithium-ion batteries, so as to solve the problems encountered in the background art.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows: A gas bag for airtightness inspection of a soft-pack lithium-ion battery includes a gas bag and a gas detection block installed at one corner of the gas bag. The gas detection block is heat-sealed in the gas bag, and the interior of the gas detection block communicates with the inner cavity of the gas bag through a diffusion hole. The inlet and outlet of the gas detection block are interference-fitted with sealing caps.

[0006] In the above scheme, the gas detection block is heat-sealed in the packaging layer of the gas bag with white glue, and the packaging layer is provided with a sealing groove connected to the white glue.

[0007] In the above scheme, the gas detection block includes an upper cylindrical area, a middle platform area, and a bottom encapsulation area. The upper cylindrical area is located at the top of the middle platform area, and the bottom encapsulation area is located at the bottom of the middle platform area.

[0008] As a preferred embodiment, the upper cylindrical region is provided with a sleeve, the sleeve having a cylindrical hole inside, the cylindrical hole communicating with a diffusion hole. The outer walls of the middle platform region and the bottom sealing region are respectively heat-sealed and fixed to the packaging layer in the air bag. The outer wall of the middle platform region is provided with multiple raised rings, the raised rings surrounding the outer wall portion connected to the packaging layer.

[0009] In the above scheme, the diffusion hole is a funnel-shaped structure with a bottom dimension larger than the top dimension, and the longitudinal section of the diffusion hole is an isosceles trapezoidal structure.

[0010] In the above scheme, the sealing cap includes a cap body and a plug. The plug is integrally installed at the bottom center of the cap body, and the top of the plug is interference-fitted with the air inlet and outlet of the gas detection block.

[0011] As a preferred embodiment, the bottom inner side of the cap body is provided with a sealing groove, the top of the plug is connected to the center of the sealing groove, and the bottom of the plug is provided with a frustum. The plug includes an upper covering layer and a lower cross plug, the outer diameter of the cross plug is smaller than the outer diameter of the covering layer, the covering layer is interference-fitted with the air inlet and outlet of the gas detector block, and the frustum is disposed at the bottom of the cross plug.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: by heat-sealing a gas detection block with through holes on one corner of the gas bag during the soft-pack battery packaging process, a full helium test is performed on the soft-pack lithium-ion battery after packaging; at the same time, a diffusion hole is set inside the gas detection block, and the electrolyte enters the battery through the diffusion hole in a diffused manner during liquid injection; an interference fit sealing cap is designed to ensure airtightness during aging; after formation, venting is carried out through the diffusion hole, and a helium test is performed again after the second sealing to further verify the airtightness and prevent leakage. Attached Figure Description

[0013] The disclosure of this utility model is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this utility model. In the drawings, the same reference numerals are used to refer to the same parts. Wherein: Figure 1 This is a cross-sectional view of the main body of this utility model; Figure 2 This is a cross-sectional schematic diagram of the gas detection block in this utility model; Figure 3 This is a bottom view of the gas detection block in this utility model; Figure 4 This is a front view of the sealing cap in this utility model; Figure 5This is a cross-sectional view of the sealing cap in this utility model; Figure 6 This is a process flow diagram of the full inspection method of this utility model.

[0014] Numbering in the diagram: 1-Air bag; 11-Packaging layer; 12-Sealing groove; 2-Gas detection block; 21-Diffusor hole; 22-Cylindrical hole; 23-White glue; 24-Raised ring; 25-Upper cylindrical area; 26-Middle platform area; 27-Bottom sealing area; 3-Sealing cap; 31-Cap body; 32-Plug; 33-Frustum; 34-Cross plug; 35-Covering layer; 36-Sealing groove. Detailed Implementation

[0015] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the utility model will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of this utility model, and therefore only show the relevant components of this utility model.

[0016] Based on the technical solution of this utility model, without changing the essential spirit of this utility model, those skilled in the art can propose various interchangeable structural methods and implementation methods. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative descriptions of the technical solution of this utility model, and should not be regarded as the entirety of this utility model or as a limitation or restriction of the technical solution of this utility model.

[0017] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0018] Example 1, as Figure 1 As shown, a gas bag for airtightness inspection of a soft-pack lithium-ion battery includes a gas bag 1 and a gas inspection block 2 installed at one corner of the gas bag 1. The gas bag 1 encloses the soft-pack lithium-ion battery inside, and the gas inspection block 2 is heat-sealed in the gas bag 1. The interior of the gas inspection block 2 is connected to the inner cavity of the gas bag 1 through a diffusion hole 21 to facilitate the introduction of electrolyte and the exhaust of air. The inlet and outlet of the gas inspection block 2 are fitted with sealing caps 3 for sealing after the gas inspection is completed.

[0019] This solution includes a gas detection block 2 that is heat-sealed to one side of the gas bag 1 of the soft-pack lithium-ion battery. The gas detection block 2 is made of PPS injection molding, and its material is the same as the white glue 23 used for bonding conventional electrode tabs. The sealing cap 3 is also made of PP thermoplastic molding.

[0020] During the packaging process of the soft-pack battery, a gas detection block 2 with a through hole is heat-sealed on one corner of the gas bag 1. After packaging, a full helium test is performed on the soft-pack lithium-ion battery. At the same time, a diffusion hole 21 is set inside the gas detection block 2. During the electrolyte injection, the electrolyte enters the battery through the diffusion hole 21 in a diffused manner. An interference fit sealing cap 3 is also designed to ensure airtightness during the aging process. After formation, the gas is vented through the diffusion hole 21. At the same time, a helium test is performed again after the second sealing to further verify the airtightness and prevent leakage.

[0021] Example 2, based on the scheme of Example 1, involves heat-sealing the gas detection block 2 to the packaging layer 11 within the gas bag 1 using white adhesive 23. The packaging layer 11 has a sealing groove 12 connected to the white adhesive 23. The white adhesive 23 is heat-melted at a high temperature of approximately 130°C, and then the gas detection block 2 is sealed in the gas bag 1 through the sealing groove 12. Alternatively, other methods can be used to seal and fix the gas detection block 2 to one corner of the gas bag 1.

[0022] Example 3, based on the solution of Example 1, please refer to... Figure 2 The gas detection block 2 includes an upper cylindrical area 25, a middle platform area 26 and a bottom encapsulation area 27. The upper cylindrical area 25 is located at the top of the middle platform area 26 and the bottom encapsulation area 27 is located at the bottom of the middle platform area 26.

[0023] The upper cylindrical area 25 is equipped with a sleeve, and the sleeve has a cylindrical hole 22 inside. The cylindrical hole 22 is connected to the diffuser hole 21. The cylindrical hole 22 and the diffuser hole 21 penetrate the entire gas detection block 2, so that the electrolyte can be smoothly introduced or the exhaust operation can be performed during full inspection. The outer wall of the middle platform area 26 and the outer wall of the bottom sealing area 27 are heat-sealed to the packaging layer 11 in the gas bag 1. The outer periphery of the bottom diffuser hole 21 of the bottom sealing area 27 is also heat-sealed with the gas bag 1. In this way, the edges connected to the gas bag 1 are sealed after heat sealing to prevent electrolyte leakage and helium leakage during detection. The outer wall of the middle platform area 26 is provided with multiple raised rings 24. The raised rings 24 surround the outer wall part connected to the packaging layer 11, which can better improve the tightness after heat sealing.

[0024] Example 4, based on the solution of Example 1, please refer to... Figure 2 and Figure 3The diffuser hole 21 has a flared shape with a bottom dimension larger than the top dimension, and its longitudinal cross-section is an isosceles trapezoid. Furthermore, the entire gas detection block 2 has a block-like structure, allowing its lower part to be sealed and connected to the gas bag 1 during heat sealing. The gas detection block 2 is small in size, occupying only a corner of the gas bag 1, making it easy to remove later. The white adhesive 23 is wrapped around the outer wall of the gas detection block 2 for heat sealing and fixation to the gas bag 1. Its sides may have outward protrusions to match the sealing groove 12, resulting in a tighter connection, improved stability, and better sealing performance.

[0025] Example 5, based on the solution of Example 1, please refer to... Figure 4 and Figure 5 The sealing cap 3 is made of rubber or PP injection molding, has a certain degree of elastic deformation, and can maintain its original shape. The sealing cap 3 includes a cap body 31 and a plug 32. The plug 32 is integrally installed at the bottom center of the cap body 31. The top of the plug 32 is interference-fitted with the air inlet and outlet of the gas detection block 2, which improves the sealing performance during gas detection.

[0026] In specific implementation, a sealing groove 36 is provided on the inner side of the bottom of the cap body 31, the top of the plug 32 is connected to the center of the sealing groove 36, and the bottom of the plug 32 is provided with a frustum 33, which serves as a guide to facilitate insertion into the cylindrical hole 22.

[0027] The plunger 32 includes an upper covering layer 35 and a lower cross plug 34. The outer diameter of the cross plug 34 is smaller than that of the covering layer 35. The covering layer 35 is interference-fitted with the air inlet and outlet of the air detector block 2. The frustum 33 is located at the bottom of the cross plug 34.

[0028] The truncated cone 33 makes it easy to insert the sealing cap 3 into the gas detector block 2. The plug 32 is a cylinder with a diameter slightly larger than the cylindrical hole 22 of the gas detector block 2. It seals the soft-pack lithium-ion battery with the gas detector block 2 through an interference fit. The cap body 31 further ensures the airtightness of the soft-pack lithium-ion battery during the formation and aging process by covering the upper cylindrical area of ​​the gas detector block 2. The sealing groove 36 is a groove that matches the upper cylindrical area 25 of the gas detector block 2, and plays a role in covering and sealing.

[0029] Example 6, as Figure 6 As shown in the process flow diagram, a full inspection method for the airtightness inspection airbag of the soft-pack lithium-ion battery described in Examples 1-5 is as follows: Firstly, during the encapsulation process, the gas detection block 2 is heat-sealed to the soft-pack battery on one side of the gas bag 1 using the same method as the top seal, via white adhesive 23. After encapsulation, helium is injected through the gas detection block 2 to perform a full helium leak test on the soft-pack batteries. After passing the helium leak test, the lithium batteries are baked. After baking, the gas detection block 2 is evacuated and then injected with electrolyte under negative pressure. The electrolyte diffuses into the soft-pack battery through the gas detection block 2, resulting in better electrolyte wetting. The baking temperature is below 90 degrees Celsius.

[0030] After the liquid injection is completed, the sealing cap 3 is inserted into the cylindrical hole 22 at the top of the gas detection block 2 for sealing. After the soft-pack lithium-ion battery is formed and aged, the gas generated during the formation is removed by vacuuming through the gas detection block 2. Then, the gas bag edge of the soft-pack lithium-ion battery is sealed again under vacuum. After the second sealing, the soft-pack lithium-ion battery is injected with helium through the gas detection block 2 for a full helium gas tightness test. After the test is completed, the side of the gas bag 1 is cut off together with the gas detection block 2.

[0031] This invention performs two helium leak tests on the soft-pack lithium-ion battery by encapsulating the gas detection block 2 on one side corner of the gas bag 1, thereby improving the risk of leakage during the production and use of the soft-pack lithium-ion battery. At the same time, the internal through hole of the gas detection block 2 is set as a diffusion hole 21, so that the electrolyte is drawn into the soft-pack lithium-ion battery in a diffusion manner during the liquid injection process, thereby improving the electrode wetting effect.

[0032] This invention ensures the airtightness of the pouch lithium-ion battery during formation and aging by setting an interference-fit sealing cap 3. In the full inspection method of this invention, the gas generated during formation in the second sealing process is extracted by the gas detection block 2 and then directly heat-sealed. Compared with the traditional second sealing method of first heat-sealing the edge of the gas bag and then inserting a dagger to draw a vacuum, this method can prevent metal debris from entering the pouch lithium-ion battery and causing the risk of short circuit.

[0033] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A gas bag for full inspection of the airtightness of a soft-pack lithium-ion battery, characterized in that: It includes an air bag (1) and an air detection block (2) installed on one corner of the air bag (1). The air detection block (2) is heat-sealed in the air bag (1). The interior of the air detection block (2) is connected to the inner cavity of the air bag (1) through a diffusion hole (21). The air inlet and outlet of the air detection block (2) are press-fitted with sealing caps (3).

2. The air bag for full airtightness inspection of a soft-pack lithium-ion battery according to claim 1, characterized in that: The gas detector block (2) is heat-sealed in the packaging layer (11) of the gas bag (1) by white glue (23), and the packaging layer (11) is provided with a sealing groove (12) connected to the white glue (23).

3. The air bag for full airtightness inspection of a soft-pack lithium-ion battery according to claim 1, characterized in that: The gas detection block (2) includes an upper cylindrical area (25), a middle platform area (26) and a bottom encapsulation area (27). The upper cylindrical area (25) is located at the top of the middle platform area (26), and the bottom encapsulation area (27) is located at the bottom of the middle platform area (26).

4. The air bag for full airtightness inspection of a soft-pack lithium-ion battery according to claim 3, characterized in that: The upper cylindrical area (25) is provided with a sleeve, and a cylindrical hole (22) is opened inside the sleeve. The cylindrical hole (22) is connected to the diffusion hole (21).

5. The air bag for full inspection of the airtightness of a soft-pack lithium-ion battery according to claim 3, characterized in that: The outer walls of the middle platform area (26) and the bottom encapsulation area (27) are respectively heat-sealed and fixed to the packaging layer (11) in the air bag (1).

6. The air bag for full airtightness inspection of a soft-pack lithium-ion battery according to claim 5, characterized in that: The outer wall of the central platform area (26) is provided with multiple raised rings (24), which surround the outer wall portion connected to the packaging layer (11).

7. The air bag for full airtightness inspection of a soft-pack lithium-ion battery according to claim 1, characterized in that: The diffuser hole (21) is a funnel-shaped structure with a bottom dimension larger than the top dimension, and the longitudinal section of the diffuser hole (21) is an isosceles trapezoidal structure.

8. The air bag for full airtightness testing of a soft-pack lithium-ion battery according to claim 1, characterized in that: The sealing cap (3) includes a cap body (31) and a plug (32). The plug (32) is integrally installed at the bottom center of the cap body (31), and the top of the plug (32) is interference-fitted with the air inlet and outlet of the gas detector block (2).

9. The airtightness inspection air bag for a soft-pack lithium-ion battery according to claim 8, characterized in that: The bottom inner side of the cap body (31) is provided with a sealing groove (36), the top of the plug (32) is connected to the center of the sealing groove (36), and the bottom of the plug (32) is provided with a frustum (33).

10. A gas bag for full inspection of the airtightness of a soft-pack lithium-ion battery according to claim 9, characterized in that: The plug (32) includes an upper covering layer (35) and a lower cross plug (34). The outer diameter of the cross plug (34) is smaller than that of the covering layer (35). The covering layer (35) is interference-fitted with the air inlet and outlet of the air detector block (2). The truncated cone (33) is located at the bottom of the cross plug (34).

Images