A method and system for detecting helium in batteries

Abstract

This disclosure provides a battery helium testing method and system, relating to the field of battery helium testing technology. The method includes: injecting helium into the battery after welding the battery cover plate, and performing a first helium test on the welded position of the battery cover plate; after passing the first helium test, injecting electrolyte and helium into the battery, and then sealing the injection hole by welding; applying back pressure helium filling to the injection hole position; performing a second helium test on the welded position of the battery cover plate and the sealed welded position of the injection hole; and determining whether the battery is qualified based on the result of the second helium test. This disclosure can improve the effectiveness of battery helium testing.

Description

Technical Field

[0001] This disclosure relates to the field of battery helium detection technology, specifically to a battery helium detection method and detection system. Background Technology

[0002] Helium testing is a process used to inspect the welding effect of batteries. Its purpose is to prevent problems such as leaks or cracks that are not visible to the naked eye in the welded batteries, thereby reducing the risk of electrolyte leakage after electrolyte injection.

[0003] In existing technologies, helium testing of batteries typically involves a first helium test on the welded area of ​​the battery cover before electrolyte injection and a second helium test on the sealed area (at the injection hole) after electrolyte injection. However, the first helium test on the welded area of ​​the cover, performed before electrolyte injection, overlooks the possibility that subsequent electrolyte injection and injection hole sealing processes may damage the weld seam of the battery cover, causing the first helium test to fail. Furthermore, existing technologies typically use a combination of adhesive studs and aluminum stud welding to seal the injection hole. Due to the sealing effect of the adhesive studs, the second helium test risks failing to detect leaks at the aluminum stud welding point. Summary of the Invention

[0004] To address the problems existing in the prior art, this disclosure provides a battery helium detection method and system to improve the effectiveness of battery helium detection. Specifically, it includes the following technical solutions:

[0005] A first aspect of this disclosure provides a battery helium detection method, comprising:

[0006] S1. After the battery cover is welded, helium is injected into the battery to perform the first helium test on the welded position of the battery cover.

[0007] S2. After the first helium test is passed, electrolyte and helium are injected into the battery, and then the injection hole is sealed by welding.

[0008] S3. Apply back pressure helium to the injection port.

[0009] S4. Perform a second helium test on the welding positions of the battery cover plate and the sealing welding positions of the injection hole.

[0010] S5. Determine whether the battery is qualified based on the results of the second helium test.

[0011] A second aspect of this disclosure provides a battery helium detection system, comprising:

[0012] The first helium detection unit is used to inject helium into the battery after the battery cover is welded, and to perform the first helium detection on the welded position of the battery cover.

[0013] The sealing unit is used to inject electrolyte and helium into the battery after the first helium test is passed, and then seal the injection hole by welding.

[0014] The back pressure helium filling unit is used to fill the injection port with helium under back pressure.

[0015] The secondary helium detection unit is used to perform a second helium gas test on the welding positions of the battery cover plate and the sealing welding positions of the injection hole.

[0016] The analysis unit is used to determine whether the battery is qualified based on the results of the second helium test.

[0017] The beneficial effects of the technical solutions provided in this disclosure are:

[0018] In this embodiment, a secondary helium gas inspection of the battery cover welding position is achieved without adding any inspection steps. This allows for the detection of damage to the battery cover welding area caused by the previous helium gas inspection, ensuring the effectiveness of the helium gas inspection. Furthermore, this embodiment adds a helium gas inspection step for the injection hole sealing welding position. After completing the glue nail sealing and aluminum nail welding of the injection hole, a back-pressure helium filling combined with helium gas inspection is used to ensure the effectiveness of the helium gas inspection at the injection hole sealing welding position.

[0019] Advantages of this disclosure in some respects will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a battery helium detection method provided in an embodiment of this disclosure;

[0022] Figure 2 This is a schematic diagram of the structure of a battery used for helium detection in an embodiment of this disclosure.

[0023] The labels in the attached diagram represent: 1. Battery cover; 2. Fluid injection hole. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0025] Figure 1 This is a flowchart of a battery helium detection method provided in an embodiment of this disclosure. See also... Figure 1 The method includes:

[0026] S1. After the battery cover is welded, helium is injected into the battery to perform the first helium test on the welded position of the battery cover.

[0027] S2. After the first helium test is passed, electrolyte and helium are injected into the battery, and then the injection hole is sealed by welding.

[0028] S3. Apply back pressure helium to the injection port.

[0029] S4. Perform a second helium test on the welding positions of the battery cover plate and the sealing welding positions of the injection hole.

[0030] S5. Determine whether the battery is qualified based on the results of the second helium test.

[0031] This method is applicable to various common power battery structures, including square aluminum-cased batteries and cylindrical batteries. Addressing potential failure issues in traditional helium detection processes, it achieves reliable detection of the battery cover and electrolyte filling hole location without requiring additional testing steps. For ease of description, the following explanation uses a square aluminum-cased battery as an example. Figure 2 As shown, the square aluminum-cased battery includes a battery cover plate 1 and an injection port 2. In traditional helium detection processes, after welding the battery cover plate 1, helium is injected into the battery through the injection port 2 for a first helium test to check the sealing status of the welded area of ​​the battery cover plate. After the first helium test passes, electrolyte is injected into the battery through the injection port, and helium is injected again. Then, the injection port is sealed with adhesive nails and aluminum nails are welded to achieve a seal. A second helium test is then performed on the sealed injection port. However, this method carries the risk of helium detection failure. On the one hand, the first helium test on the battery cover plate only ensures that there are no leaks in the welded area before electrolyte injection, but it cannot detect potential leaks caused by damage to the welded area during subsequent processing. On the other hand, the second helium test at the sealed injection port carries the risk of detection failure due to the tight seal of the adhesive nails resulting in a low helium concentration between the aluminum nails and the adhesive nails, meaning that even if there are leaks at the aluminum nail weld, the helium concentration cannot be detected.

[0032] Based on this, the detection method provided in this embodiment performs two helium gas tests on the cover plate welding position, adding a helium gas test after sealing welding (aluminum nail welding), thereby improving the effectiveness of helium gas testing on the battery cover plate welding position; at the same time, it adds back pressure testing on the sealing welding effect of the injection hole, and performs testing immediately after helium filling for the back pressure of the sealing welding position, thereby ensuring the effectiveness of the test.

[0033] In step S1, after the battery cover is welded, helium is injected into the battery through the injection hole. Then, the helium leakage rate is detected at the welded position of the cover. This is the first helium test to detect batteries with poor cover welding.

[0034] In step S2, if the first helium test fails, the battery is stored in the NG buffer; if it passes, subsequent tests are performed. After injecting electrolyte into the battery through the injection hole, helium is injected into the battery again through the injection hole. Then, a plastic nail is inserted, and an aluminum nail is used for laser welding to seal the joint, welding the aluminum nail to the battery casing as one piece.

[0035] In step S3, the battery is placed in the back-pressure helium charging station. The battery is placed with the injection port facing upwards. A sealing helium compression mechanism is provided at the back-pressure helium charging station. The end of the sealing helium compression mechanism has a sealing ring. The end of the sealing helium compression mechanism is aligned with the injection port and moves downwards until the sealing ring is in tight contact with the battery injection port. Then, helium is charged into the aluminum nail welding position, i.e., the sealing welding position of the injection port, using back pressure. At this time, if there is a leak at the aluminum nail welding position, helium can be injected into the gap between the aluminum nail and the glue nail through the leak; otherwise, helium cannot be injected. Preferably, during back-pressure helium charging, the helium pressure is set to 0.2 MPa, and the pressure holding time is 60 seconds.

[0036] In step S4, the battery is transferred to the helium testing station. At this point, helium is present inside the battery, and there may also be helium in the gap between the aluminum and rubber nails at the injection port. The battery is placed in the helium testing chamber, and the chamber is evacuated. Helium testing is then performed simultaneously on the battery cover weld and the injection port sealing weld. If the helium concentration at the battery cover weld exceeds the standard, it indicates a leak at the weld; if the helium concentration at the injection port sealing weld (aluminum nail weld) exceeds the standard, it indicates a leak at the aluminum nail weld. An additional helium test is performed on the battery cover weld, resulting in two helium tests. This avoids potential damage to the cover weld caused by processing steps after the first helium test, further improving the reliability of the helium test. Simultaneously, the injection port sealing weld is tested using a back-pressure helium filling method, which more accurately detects leaks at the aluminum nail weld, increasing the leak detection rate and thus improving battery safety.

[0037] In step S5, the second helium gas test result is obtained, and leakage analysis is performed on the cover plate welding and aluminum nail welding positions. If the helium gas test result at the battery cover plate welding position fails, the battery is stored in the NG buffer area, and the cover plate welding process and the liquid injection hole sealing welding process are analyzed to determine the cause of the leakage. If the helium gas test result at the aluminum nail welding position fails, the battery is stored in the NG buffer area, and the aluminum nail welding process is analyzed. If the helium gas test result passes, it indicates that the battery is qualified and proceeds to the next station for subsequent processing.

[0038] In this embodiment of the invention, based on the battery helium detection method provided above, a battery helium detection system is further provided, comprising:

[0039] The primary helium detection unit is used to inject helium into the battery after the battery cover is welded, and to perform the first helium gas detection on the welded position of the battery cover; the primary helium detection unit can be a helium detector;

[0040] The sealing unit is used to inject electrolyte and helium into the battery after the first helium test is passed, and then seal the injection hole by welding. The electrolyte and helium can be injected using existing injection devices, and the sealing welding of the injection hole can also be performed using existing technologies, such as laser welding.

[0041] The back pressure helium filling unit is used to perform back pressure helium filling at the injection port. The back pressure helium filling unit is set at the back pressure helium filling station and includes a sealing helium filling mechanism set above the station. The end of the sealing helium filling mechanism has a sealing ring. During back pressure helium filling, the end of the sealing helium filling mechanism is aligned with the injection port and moves downward until the sealing ring is in close contact with the battery injection port. Then, according to the preset pressure and holding time, the injection port is filled with back pressure helium.

[0042] The secondary helium detection unit is used to perform a second helium gas test on the welding positions of the battery cover plate and the sealing welding positions of the injection hole.

[0043] The analysis unit is used to determine whether the battery is qualified based on the results of the second helium test.

[0044] In some embodiments, a transfer tray with multiple battery mounting fixtures is also included for securing the battery in the position with the injection hole facing upward and for transferring the battery between different stations.

[0045] In some implementations, a robotic arm is also included to transfer and load / unload batteries between workstations.

[0046] In some implementations, an NG buffer area is also included. The NG buffer area is a buffer area for storing batteries that fail the helium test. For batteries that fail the first helium test and the second helium test, a robotic arm is used to pick them up in the unloading area and transfer them to the NG buffer area for subsequent process analysis.

[0047] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for detecting helium in a battery, characterized in that, include: After the battery cover is welded, helium is injected into the battery, and the welded position of the battery cover is tested for the first time with helium. After the first helium test is passed, electrolyte and helium are injected into the battery, and then the injection hole is sealed by welding. Helium was charged under back pressure at the injection port location; A second helium test was performed on the welding positions of the battery cover and the sealing welding positions of the injection hole. The battery's quality is determined based on the results of the second helium test.

2. The battery helium detection method as described in claim 1, characterized in that, The sealing welding of the injection hole includes inserting a rubber nail into the injection hole for sealing, and welding an aluminum nail at the injection hole to seal the injection hole.

3. The battery helium detection method as described in claim 2, characterized in that, Back pressure helium is applied to the aluminum nail welding position at the injection hole. If there is a leak at the aluminum nail welding position, helium is injected into the gap between the aluminum nail and the glue nail through the leak.

4. The battery helium detection method as described in claim 3, characterized in that, The battery is placed with the liquid injection hole facing upwards. A sealing helium compression mechanism is set at the back pressure helium filling station. The end of the sealing helium compression mechanism has a sealing ring. The end of the sealing helium compression mechanism is aligned with the liquid injection hole and moves downwards until the sealing ring is in close contact with the position of the battery liquid injection hole, and then back pressure helium filling is performed.

5. The battery helium detection method as described in claim 1, characterized in that, The second helium gas test on the battery cover welding position and the liquid injection hole sealing welding position includes: placing the battery in the helium gas detection chamber, evacuating the helium gas detection chamber, and then simultaneously performing helium leak detection on the battery cover welding position and the liquid injection hole sealing welding position.

6. The battery helium detection method as described in claim 1, characterized in that, It also includes analyzing the cover plate welding process and the injection hole sealing welding process if the helium test result at the battery cover plate welding position fails in the second helium test to determine the cause of the leak.

7. A battery helium detection system, characterized in that, include: The first helium detection unit is used to inject helium into the battery after the battery cover is welded, and to perform the first helium detection on the welded position of the battery cover. The sealing unit is used to inject electrolyte and helium into the battery after the first helium test is passed, and then seal the injection hole by welding. The back pressure helium filling unit is used to fill the injection port with helium under back pressure. The secondary helium detection unit is used to perform a second helium gas test on the welding positions of the battery cover plate and the sealing welding positions of the injection hole. The analysis unit is used to determine whether the battery is qualified based on the results of the second helium test.

8. The battery helium detection system as described in claim 7, characterized in that, It also includes a transfer tray with multiple battery mounting fixtures for securing the batteries in the position with the injection hole facing upwards and for transferring the batteries between different workstations.

9. A battery helium detection system as described in claim 7, characterized in that, It also includes robotic arms, used to transfer batteries between workstations and to load and unload them.

10. A battery helium detection system as described in claim 7, characterized in that, The back pressure helium filling unit includes a sealed helium filling mechanism with a sealing ring at its end. During back pressure helium filling, the end of the sealed helium filling mechanism is aligned with the injection hole and moves downward until the sealing ring is in close contact with the battery injection hole. Then, back pressure helium filling is performed on the injection hole according to the preset pressure and holding time.

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