Cylindrical lithium-ion battery airtightness testing device and system

Abstract

This utility model relates to the field of cylindrical lithium-ion battery manufacturing technology, and discloses a cylindrical lithium-ion battery airtightness testing device and system. The testing device includes a clamping mechanism covering the outside of the battery cell; a sleeve fitted onto the outside of the clamping mechanism; a fixed base located at the bottom of the sleeve, with an air inlet channel and a perforation channel connected; a fixed cap located at the top of the sleeve and forming a sealed cavity with the sleeve, fixed base, and battery cell, and having a through hole corresponding to the cap area of ​​the battery cell; a two-way valve located at the bottom of the fixed base and connected to the perforation channel; and a piercing mechanism located at the end of the two-way valve away from the fixed base, used to pierce the battery cell by passing through the two-way valve and the perforation channel when the two-way valve is open. This testing device improves the speed of airtightness testing during battery cell production and enhances the accuracy of the test data.

Description

Technical Field

[0001] The utility model relates to the technical field of the production and manufacturing of cylindrical lithium - ion batteries, and particularly relates to an airtightness detection device and a detection system for cylindrical lithium - ion batteries. Background Technique

[0002] In the field of lithium - ion battery manufacturing, airtightness detection is the core quality control link throughout the entire life cycle of research and development, production, and application. As one of the important performance indicators of lithium - ion batteries, airtightness has a crucial impact on the performance, life, and safety of the batteries. And as a key component of the new energy industry, the safety and reliability of lithium - ion batteries are directly related to the safe development of the entire new energy industry.

[0003] However, when detecting the airtightness of cylindrical lithium - ion batteries at present, it is necessary to first punch holes in the sealed battery cores, and then install the punched battery cores into the airtightness detection fixture for testing. This traditional detection method is not only cumbersome and time - consuming, but in actual operation, it is very difficult to ensure that each punching can accurately align with the pressure - testing hole. This not only increases the operation difficulty, but may also lead to inaccurate detection results, thereby reducing the consistency of battery production, resulting in a large difference in airtightness performance between different batches or different products, which is not conducive to the stability and control of product quality. In addition, inaccurate airtightness detection results may cover up potential safety hazards existing in the batteries themselves, affecting the safety performance of the battery cores. Content of the Utility Model

[0004] The purpose of the utility model is to at least solve one of the technical problems existing in the prior art, and provide an airtightness detection device and a detection system for cylindrical lithium - ion batteries. The airtightness detection device for cylindrical lithium - ion batteries improves the airtightness detection speed in the battery core production process, improves data accuracy, and greatly improves the battery production consistency and the safety performance of the battery cores.

[0005] In order to achieve the above purpose, on one hand, the utility model provides an airtightness detection device for cylindrical lithium - ion batteries, including:

[0006] A clamping mechanism, which is wrapped around the outside of the battery core;

[0007] A sleeve, which is sleeved on the outside of the clamping mechanism;

[0008] A fixed base, which is arranged at the bottom of the sleeve, and an air inlet channel and a punching channel are opened on the fixed base, and the air inlet channel is communicated with the punching channel;

[0009] A fixed cap, which is arranged at the top of the sleeve and forms a sealed cavity in cooperation with the sleeve, the fixed base, and the battery core, and a through - hole corresponding to the cap area of the battery core is provided on the fixed cap;

[0010] A two-way valve is located at the bottom of the fixed base and communicates with the perforated channel;

[0011] A puncture mechanism is located at the end of the two-way valve away from the fixed base. It is used to pass through the two-way valve and the perforation channel to puncture the battery cell when the two-way valve is open, and to cooperate with the air intake channel to perform airtightness testing.

[0012] Optionally, the clamping mechanism includes two semi-circular claws with a cross-section of semi-circular ring. Each semi-circular claw has a semi-circular ring groove on the inner arc surface of one end that fits into the rolling groove of the battery cell. The two semi-circular claws are used to wrap and fix the battery cell after docking.

[0013] Optionally, the top surface of the fixing base is provided with a groove communicating with the punched channel, and the groove is directly opposite the battery cell.

[0014] Optionally, the groove is provided with an elastic washer with a central hole.

[0015] Optionally, the puncture mechanism includes:

[0016] Spikes;

[0017] A screw portion, one end of which is connected to the spike portion;

[0018] A connector is threaded onto the screw portion, and one end of the connector extends into the interior of the two-way valve and is threadedly connected to the inner wall of one end of the two-way valve.

[0019] Optionally, a rotating handle is provided at the end of the screw portion away from the spike portion.

[0020] Optionally, a conical surface is formed on the inner wall of the through hole.

[0021] Optionally, the fixing cap is detachably connected to the top of the sleeve.

[0022] Optionally, it also includes a flange plate disposed between the fixed base and the two-way valve, the bottom of the flange plate being provided with an external threaded sleeve, the external threaded sleeve being threadedly connected to the inner wall of one end of the two-way valve.

[0023] The second aspect of this utility model provides a cylindrical lithium-ion battery airtightness detection system, comprising:

[0024] The aforementioned cylindrical lithium-ion battery airtightness testing device;

[0025] The output end of the gas injection device is connected to the air inlet channel of the cylindrical lithium-ion battery airtightness detection device.

[0026] Through the above technical solution, by setting up a double-way valve and a puncture mechanism, when the double-way valve is open, the puncture mechanism can directly puncture the battery cell through the double-way valve and the punching channel, simplifying the punching process during testing and improving testing efficiency. The air inlet channel is connected to the punching channel, and air tightness testing can be performed immediately after puncture without transferring the battery cell or changing the fixture, reducing human intervention and improving production consistency. The fixed cap, sleeve, fixed base and battery cell cooperate to form a sealed cavity, ensuring air tightness before and after puncture, improving the accuracy of test data. At the same time, the through hole on the fixed cap corresponds to the cap area of ​​the battery cell. In the later stage of air tightness testing, water injection test is performed through the through hole, further improving the reliability of the test. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a cylindrical lithium-ion battery airtightness testing device provided by this utility model;

[0028] Figure 2 This is a cross-sectional view of a cylindrical lithium-ion battery airtightness testing device provided by this utility model;

[0029] Figure 3 This is a schematic diagram of the clamping mechanism in this utility model;

[0030] Figure 4 This is a schematic diagram of the puncture mechanism in this utility model.

[0031] Explanation of reference numerals in the attached figures

[0032] 1. Sleeve; 11. Sealed cavity; 2. Fixed base; 21. Drilled channel; 22. Air inlet channel; 23. Groove; 3. Fixed cap; 31. Conical surface; 4. Two-way valve; 5. Puncture mechanism; 51. Spike part; 52. Screw part; 53. Connector; 54. Rotating handle; 6. Half claw; 61. Semi-circular annular groove; 7. Elastic washer; 8. Flange plate; 9. Battery cell. Detailed Implementation

[0033] The specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.

[0034] Combination Figure 1 and Figure 2 As shown, the cylindrical lithium-ion battery airtightness testing device provided by this utility model mainly includes a clamping mechanism, a sleeve 1, a fixed base 2, a fixed cap 3, a two-way valve 4, and a puncture mechanism 5.

[0035] Specifically, the clamping mechanism covers the outside of the battery cell 9 to fix the battery cell 9; the sleeve 1 is sleeved on the outside of the clamping mechanism to further fix the battery cell 9 and the clamping mechanism; the fixing base 2 is located at the bottom of the sleeve 1, and the fixing base 2 has an air inlet channel 22 and a drilling channel 21. The air inlet channel 22 is connected to the drilling channel 21. The air inlet channel 22 can be opened on the side wall of the fixing base 2 to connect to the gas injection device so that gas can enter the sealed cavity 11 to provide a pressure source for air tightness testing. The drilling channel 21 axially penetrates the fixing base 2 and is coaxially connected with the sleeve 1 to provide a channel for the subsequent piercing mechanism 5 to pierce the steel shell of the battery cell 9; the fixing cap 3 is located at the top of the sleeve 1 and cooperates with the sleeve 1, the fixing base 2 and the battery cell 9 to form the sealed cavity 11. The fixing cap 3 has a through hole corresponding to the cap area of ​​the battery cell 9. The fixing cap 3 can limit The position of one end of the axial direction of the battery cell 9 serves a positioning function. The through hole exposes the cap area of ​​the battery cell 9. In the later stage of airtightness testing, water is injected into the cap of the battery cell 9 through the through hole to further check the airtightness of the steel shell of the battery cell 9. The double-way valve 4 is set at the bottom of the fixed base 2 and is connected to the drilling channel 21. It is used to control the opening and closing of the drilling channel 21. When it is necessary to puncture the battery cell 9 for testing, the double-way valve 4 is operated to open it. When it is not necessary to puncture, the double-way valve 4 is closed to maintain the sealing of the sealed cavity 11 and the drilling channel 21. The puncture mechanism 5 is set at the end of the double-way valve 4 away from the fixed base 2. It is used to puncture the battery cell 9 by passing through the double-way valve 4 and the drilling channel 21 when the double-way valve 4 is open. When air is supplied into the battery cell 9 through the air inlet channel 22 to pressurize it, it can detect whether there is a leak point inside the battery cell 9 and realize the airtightness test of the battery cell 9.

[0036] In this utility model, such as Figure 3 As shown, the clamping mechanism includes two semi-circular claws 6 with a cross-section of semi-circular ring. Each semi-circular claw 6 has a semi-circular ring groove 61 on the inner arc surface of one end that fits into the rolling groove of the battery cell 9. The two semi-circular claws 6 are used to wrap and fix the battery cell 9 after docking.

[0037] Understandably, the two half-claws 6 can form a complete ring after docking, thus tightly wrapping the battery cell 9. Each half-claw 6 has a semi-circular annular groove 61 on the inner arc surface of one end that fits into the rolling groove of the battery cell 9, ensuring precise docking and fixation between the half-claws 6 and the battery cell 9.

[0038] In some embodiments, the length of the half-claw 6 may be less than the length of the battery cell 9, and it only wraps around and fixes the upper half of the battery cell 9.

[0039] In this utility model, in order to improve the drilling accuracy and enhance the stability of the drilling operation, the top surface of the fixed base 2 is provided with a groove 23 that communicates with the drilling channel 21, and the groove 23 is directly opposite the battery cell 9.

[0040] It is understandable that the shape and size of the groove 23 are designed according to the shape and size of the battery cell 9 to ensure that the battery cell 9 can be stably placed in the groove 23 and is not easy to move or shake. The position of the groove 23 is directly opposite the battery cell 9. That is, when the battery cell 9 is placed in the groove 23, the position where it needs to be drilled is aligned with the center line of the drilling channel 21, so that subsequent drilling operations can be carried out accurately.

[0041] In addition, the design of the groove 23 allows the battery cell 9 to automatically align with the punching channel 21, so the operator does not need to perform complicated adjustments or alignment operations, which simplifies the punching process and reduces the difficulty of operation.

[0042] Furthermore, an elastic washer 7 with a central hole is provided in the groove 23.

[0043] The elastic washer 7 is configured as an annular structure with a central hole, the size of which matches the groove 23 on the fixed base 2, and can fit tightly against the inner wall of the groove 23. Its central hole is aligned with the punching channel 21, which facilitates the punching operation. When punching, the piercing mechanism 5 can pass directly through the central hole without additional adjustment and alignment, which is convenient and labor-saving.

[0044] In addition, the elastic properties of the elastic washer 7 allow it to deform to a certain extent when the battery cell 9 is placed, thereby tightly fitting the bottom surface of the battery cell 9. This not only enhances the connection stability of the battery cell 9 within the sleeve 1, but also absorbs some of the impact and vibration generated during the drilling process, indirectly ensuring the accuracy and reliability of the final test data.

[0045] In this utility model, such as Figure 4 As shown, the puncture mechanism 5 includes a spike portion 51, a screw portion 52, and a connector 53.

[0046] Specifically, one end of the screw portion 52 is connected to the spike portion 51, and the connector 53 is threaded onto the screw portion 52. One end of the connector 53 extends into the interior of the double-way valve 4 and is threadedly connected to the inner wall of one end of the double-way valve 4.

[0047] Understandably, in order to easily pierce the steel casing of the battery cell 9, the material of the spike 51 can be made of a material with sufficient hardness and strength to ensure that it is not easily deformed or damaged during the drilling process.

[0048] One end of the screw portion 52 is tightly connected to the spike portion 51. Any suitable connection method known to those skilled in the art, such as welding or integral connection, can be used, as long as it ensures that the two will not separate under stress. The surface of the screw portion 52 is threaded for threaded connection with the connector 53.

[0049] The connector 53 is a hollow structure with a threaded hole inside that matches the thread of the screw part 52. One end of the connector 53 extends into the interior of the two-way valve 4, and its outer surface is also provided with a thread that matches the thread on the inner wall of one end of the two-way valve 4, so as to make a threaded connection with the two-way valve 4.

[0050] With this setup, the position and puncture depth of the spike 51 can be adjusted by rotating the screw 52.

[0051] Furthermore, the threaded connection between the connector 53 and the two-way valve 4, as well as the tight fit between the screw portion 52 and the connector 53, ensures the sealing between the piercing mechanism 5 and the two-way valve 4. Moreover, if the piercing mechanism 5 is damaged or worn during use, the connector 53 and the screw portion 52 can be easily disassembled for replacement or repair.

[0052] In some embodiments, the connector 53 is integrally connected to the end of the two-way valve 4 away from the perforated channel 21.

[0053] Furthermore, in order to improve the convenience for operators to use the piercing mechanism 5 for drilling, a rotating handle 54 is provided at the end of the screw part 52 away from the spike part 51. By rotating the rotating handle 54, the screw part 52 is driven to rotate, thereby driving the spike part 51 to perform the drilling operation.

[0054] In some embodiments, the puncture mechanism 5 can be driven electrically. It is understood that when the puncture mechanism 5 is driven electrically, its connection structure and method with the two-way valve 4 can be adapted to the characteristics of electric drive, as long as the stability of the connection between the puncture mechanism 5 and the two-way valve 4 under electric drive and the normal operation of the overall system are ensured.

[0055] In this invention, the fixing cap 3 is detachably connected to the top of the sleeve 1. The fixing cap 3 and the top of the sleeve 1 can be provided with matching connection structures. For example, the inner wall of the fixing cap 3 has internal threads, and the outer wall of the top of the sleeve 1 has external threads, achieving a detachable connection through threaded engagement. Alternatively, a snap-fit ​​connection can be used, with an elastic snap-fit ​​on the inner side of the fixing cap 3 and a corresponding slot on the top of the sleeve 1. During installation, the snap-fit ​​engages with the slot for fixation; during disassembly, pressing the snap-fit ​​disengages it from the slot.

[0056] In this invention, in order to ensure stable water coverage and prevent test water accumulation from causing misjudgment, a conical surface 31 is formed on the inner wall of the through hole.

[0057] In this utility model, a flange plate 8 is also included, which is disposed between the fixed base 2 and the double-way valve 4. The bottom of the flange plate 8 is provided with an external threaded sleeve 1, which is threadedly connected to the inner wall of one end of the double-way valve 4.

[0058] Understandably, the flange plate 8, as a transition component between the fixed base 2 and the two-way valve 4, can evenly distribute the forces between the two. The flange plate 8 can be circular or other plate-shaped structures adapted to the connection between the fixed base 2 and the two-way valve 4. An external threaded sleeve 1 is integrally formed or welded to the center of its bottom. The size and thread specification of the external threaded sleeve 1 match the thread on the inner wall of one end of the two-way valve 4 to ensure a smooth threaded connection.

[0059] In another aspect, this utility model provides a cylindrical lithium-ion battery airtightness testing system. The system includes the aforementioned cylindrical lithium-ion battery airtightness testing device and an injection device. By connecting the output end of the injection device to the air inlet channel 22 of the cylindrical lithium-ion battery airtightness testing device, a pressure source is provided to the testing device. This cylindrical lithium-ion battery airtightness testing system improves the speed of airtightness testing of the battery cell 9 during production, enhances data accuracy and the safety performance of the battery cell 9, and ensures battery production consistency.

[0060] In summary, the specific embodiments of this utility model are as follows:

[0061] Pre-install the elastic washer 7 into the groove 23 on the top surface of the fixed base 2. Align the semi-circular annular slots 61 of the two half-claws 6 with the rolling groove of the battery cell 9 and embed them to wrap around the outside of the battery cell 9. With the cap of the battery cell 9 facing upwards, vertically place the battery cell 9 and the clamping mechanism into the sleeve 1, ensuring that the bottom of the battery cell 9 is in complete contact with the elastic washer 7. Tighten the fixing cap 3, open the double-way valve 4, and slowly rotate the rotating handle 54 to tighten the piercing mechanism 5, allowing its spike 51 to pierce the bottom of the steel shell of the battery cell 9 through the double-way valve 4, the perforation channel 21, and the center hole of the elastic washer 7 in sequence. Retract the spike 51 to below the valve core of the double-way valve 4 and close the double-way valve 4. At this time, open the air source, allowing gas to be continuously injected into the battery airtightness testing device through the air inlet channel 22 and the perforation channel 21, and the air pressure inside the testing device will gradually increase accordingly. At this point, gas slowly enters the internal space of the steel shell of the battery cell 9 through a pre-drilled small hole at the bottom. When the gas pressure inside the testing device reaches the breakpoint value range set by the CID of the battery cell 9 cap (usually 0.9 - 1.1 MPa), the operator uses a suitable tool (such as a dropper, syringe, etc.) to inject an appropriate amount of water into the through hole on the fixing cap 3 corresponding to the position of the battery cell 9 cap. Subsequently, the testing device is pressurized until the gas pressure reaches 1.5 MPa. During this process, closely observe whether any bubbles are generated at the cap of the battery cell 9. If no bubbles are observed within the specified time, the air tightness test of the steel shell of the battery cell 9 is deemed qualified. After the test is completed, the gas source is turned off, and the gas supply to the air inlet channel 22 is stopped. Then, the switch of the double-way valve 4 is gently loosened to allow the gas pressure inside the testing device to be released slowly until the gas pressure inside the device is balanced with the external atmospheric pressure. The battery cell 9 is then removed, completing this air tightness test.

[0062] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A cylindrical lithium-ion battery hermeticity detection device, characterized by, include: The clamping mechanism is wrapped around the outside of the battery cell (9); A sleeve (1) is fitted onto the outside of the clamping mechanism; A fixed base (2) is provided at the bottom of the sleeve (1). An air intake channel (22) and a perforation channel (21) are provided on the fixed base (2). The air intake channel (22) and the perforation channel (21) are connected. A fixing cap (3) is provided on the top of the sleeve (1) and cooperates with the sleeve (1), the fixing base (2) and the battery cell (9) to form a sealed cavity (11), and the fixing cap (3) is provided with a through hole corresponding to the cap area of ​​the battery cell (9); A two-way valve (4) is located at the bottom of the fixed base (2) and communicates with the perforated channel (21); The puncture mechanism (5) is located at one end of the double-way valve (4) away from the fixed base (2) and is used to pass through the double-way valve (4) and the punching channel (21) to puncture the battery cell (9) and cooperate with the air intake channel (22) to perform air tightness testing when the double-way valve (4) is turned on.

2. The cylindrical lithium-ion battery air tightness detection device according to claim 1, characterized in that, The clamping mechanism includes two semi-circular claws (6) with a cross-section of semi-circular ring. Each semi-circular claw (6) has a semi-circular ring groove (61) on the inner arc surface of one end that fits into the rolling groove of the battery cell (9). The two semi-circular claws (6) are used to wrap and fix the battery cell (9) after docking.

3. The cylindrical lithium-ion battery air tightness detection device according to claim 1, characterized in that, The top surface of the fixed base (2) is provided with a groove (23) that communicates with the punched channel (21), and the groove (23) is directly opposite the battery cell (9).

4. The cylindrical lithium-ion battery air tightness detection device according to claim 3, characterized in that, The groove (23) is provided with an elastic washer (7) with a central hole.

5. The cylindrical lithium-ion battery airtightness testing device according to claim 1, characterized in that, The puncture mechanism (5) includes: Spikes (51); A screw portion (52), one end of which is connected to the spike portion (51); The connector (53) is threaded onto the screw part (52), and one end of the connector (53) extends into the interior of the double-way valve (4) and is threadedly connected to the inner wall of one end of the double-way valve (4).

6. The cylindrical lithium-ion battery air tightness detection device according to claim 5, characterized in that, A rotating handle (54) is provided at the end of the screw part (52) away from the spike part (51).

7. The cylindrical lithium-ion battery air tightness detection device according to claim 1, characterized in that, A conical surface (31) is formed on the inner wall of the through hole.

8. The cylindrical lithium-ion battery air tightness detection device according to claim 1, characterized in that, The fixing cap (3) is detachably connected to the top of the sleeve (1).

9. The cylindrical lithium-ion battery air tightness detection device according to claim 1, characterized in that, It also includes a flange plate (8) located between the fixed base (2) and the two-way valve (4). The bottom of the flange plate (8) is provided with an external threaded sleeve (1), which is threaded to one end of the inner wall of the two-way valve (4).

10. A cylindrical lithium-ion battery hermeticity detection system, comprising: include: The cylindrical lithium-ion battery airtightness testing device as described in any one of claims 1-9; The output end of the gas injection device is connected to the air inlet channel (22) of the cylindrical lithium-ion battery airtightness detection device.

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