Battery helium detection method and detection system

Abstract

The invention provides a battery helium detection method and system, and relates to the technical field of battery helium detection.The method comprises the steps that after a battery cover plate is welded, helium is injected into a battery, and helium detection is conducted on the welding position of the battery cover plate for the first time; after the first helium detection is passed, electrolyte and helium are injected into the battery, and then a liquid injection hole is sealed and welded; backpressure helium filling is carried out on the liquid injection hole; carrying out secondary helium detection on the welding position of the battery cover plate and the sealing welding position of the liquid injection hole; and judging whether the battery is qualified or not according to the second helium detection result. According to the invention, the effectiveness of battery helium detection can be improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of battery helium detection, and in particular to a battery helium detection method and detection system. Background Art

[0002] Helium testing is a process for detecting the welding effect of batteries. Its purpose is to prevent the batteries from having leaks or cracks that are invisible to the naked eye after welding, thereby reducing the risk of electrolyte leakage after electrolyte injection.

[0003] In the prior art, for helium detection of batteries, the first helium detection is usually performed on the cover welding area before the electrolyte is injected and after the battery cover is welded, and the second helium detection is performed on the battery sealing area (injection hole) after the electrolyte is injected. However, the first helium detection of the cover welding area is performed before the injection, ignoring the fact that subsequent processes such as injection and injection hole sealing may cause damage to the battery cover weld, thus causing the first helium detection to fail. In addition, the prior art usually uses a combination of rubber nail sealing and aluminum nail welding to seal the injection hole. Due to the sealing effect of the rubber nail, there is a risk that the second helium detection will not be able to detect leaks at the aluminum nail welding point. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the embodiments of the present disclosure provide a battery helium detection method and detection system to improve the effectiveness of battery helium detection. Specifically, the following technical solutions are included:

[0005] A first aspect of an embodiment of the present disclosure provides a battery helium detection method, comprising:

[0006] S1. After the battery cover is welded, helium is injected into the battery and the first helium detection is performed on the welding 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 and welded;

[0008] S3, back pressure helium filling is performed on the injection hole position;

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

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

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

[0012] The primary helium inspection unit is used to inject helium into the battery after the battery cover is welded, and to perform the first helium inspection on the welding position of the battery cover;

[0013] A sealing unit, used to inject electrolyte and helium into the battery after the first helium test is passed, and then seal and weld the injection hole;

[0014] A back pressure helium filling unit is used to fill the injection hole with helium under back pressure;

[0015] Secondary helium inspection unit, used to conduct a second helium inspection on the welding position of the battery cover and the sealing welding position of the injection hole;

[0016] The analysis unit is used to determine whether the battery is qualified according to the second helium detection result.

[0017] The technical solution provided by the embodiments of the present disclosure has the following beneficial effects:

[0018] In the embodiment of the present disclosure, without adding any additional inspection process, a secondary helium inspection of the welding position of the battery cover is implemented, and the damage to the welding area of ​​the battery cover after the first helium inspection can be inspected, thereby ensuring the effectiveness of the helium inspection. In addition, the embodiment of the present disclosure adds a helium inspection process for the sealing welding position of the injection hole. After the injection hole is sealed with a rubber nail and the aluminum nail is welded, the back pressure helium filling is combined with the helium inspection method to ensure the effectiveness of the helium inspection of the sealing welding position of the injection hole.

[0019] Advantages of additional aspects of the present disclosure will be given in part in the following description and in part will become apparent from the following description or will be learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a flow chart of a battery helium detection method provided by an embodiment of the present disclosure;

[0022] Figure 2 Schematic diagram of the structure of a battery for helium detection in an embodiment of the present disclosure.

[0023] The reference numerals represent respectively: 1. battery cover; 2. liquid injection hole. DETAILED DESCRIPTION

[0024] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0025] Figure 1 is a flow chart of a battery helium detection method provided by an embodiment of the present disclosure, see Figure 1 , the method comprising:

[0026] S1. After the battery cover is welded, helium is injected into the battery and the first helium detection is performed on the welding 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 and welded;

[0028] S3, back pressure helium filling is performed on the injection hole position;

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

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

[0031] This method is applicable to various common power battery structures such as square aluminum shell batteries and cylindrical batteries. In view of the possible failure problems of the traditional helium inspection process, the battery cover and the injection hole position of the battery can be reliably inspected without adding additional inspection steps. For the convenience of description, the square aluminum shell battery is used as an example. Figure 2 As shown, the square aluminum shell battery includes a battery cover 1 and a liquid injection hole 2. After the welding of the battery cover 1 is completed, the traditional helium inspection process injects helium into the battery through the liquid injection hole 2, and performs a helium inspection to detect the sealing state of the battery cover welding area; after the first helium inspection is passed, the electrolyte is injected into the battery through the liquid injection hole, and helium is injected again, and then the liquid injection hole is sealed with glue nails and the aluminum nails are welded to achieve the sealing of the liquid injection hole, and the position of the sealed liquid injection hole is subjected to a second helium inspection. However, this method has the risk of helium inspection failure. On the one hand, the first helium inspection at the battery cover can only ensure that there is no leakage in the welding area of ​​the cover before the electrolyte is injected, but the subsequent processing process may cause damage to the welding area of ​​the cover and cause leakage risks, which cannot be detected; on the other hand, the second helium inspection at the sealing of the liquid injection hole has the risk of detection failure due to the low helium concentration between the aluminum nails and the glue nails due to the tight sealing of the glue nails, and even if there is a leakage at the welding of the aluminum nails, the helium concentration cannot be detected.

[0032] Based on this, the detection method provided in the embodiment of the present disclosure performs two helium detections on the cover plate welding position, and adds a helium detection after the sealing welding (aluminum nail welding), thereby improving the effectiveness of the helium detection of the battery cover plate welding position; at the same time, it adds a back pressure detection of the sealing welding effect of the injection hole, and performs a detection immediately after the back pressure of the sealing welding position is filled with helium, thereby ensuring the effectiveness of the detection.

[0033] In step S1, after the battery cover is welded, helium is injected into the battery through the injection hole, and then the helium leakage rate of the cover welding position is tested. 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 area; if it passes, a subsequent test is performed. After the electrolyte is injected into the battery through the injection hole, helium is injected into the battery again through the injection hole, and then the glue nails are inserted and laser welded with aluminum nails to seal the opening, and the aluminum nails are welded to the battery shell as a whole.

[0035] In step S3, the battery is placed in a back-pressure helium filling station. The battery is placed with the injection hole facing upward, and a sealed helium pressure mechanism is provided at the back-pressure helium filling station. The end of the sealed helium pressure mechanism has a sealing ring, and the end of the sealed helium pressure mechanism is aligned with the injection hole and moves downward until the sealing ring is in close contact with the battery injection hole. Then, helium is filled into the aluminum nail welding position, that is, the injection hole sealing welding position, by 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 rubber nail through the leak, otherwise helium cannot be injected. Preferably, during back-pressure helium filling, the helium pressure is set to 0.2MPa, and the pressure holding time is 60 seconds.

[0036] In step S4, the battery is transferred to the helium detection station. At this time, there is helium inside the battery, and there may be helium in the gap between the aluminum nail and the glue nail at the injection hole. The battery is placed in a helium detection chamber, the helium detection chamber is evacuated, and then the battery cover welding position and the injection hole sealing welding position are simultaneously tested for helium. If the helium concentration at the battery cover welding position exceeds the standard, it indicates that there is a leak at the cover welding position; if the helium concentration at the injection hole sealing welding position (aluminum nail welding position) exceeds the standard, it indicates that there is a leak in the aluminum nail welding. A helium detection process is added to the battery cover welding position, and a total of two helium inspections are performed, which can avoid damage to the cover welding position that may be caused by the processing procedures after the first helium detection, and further improve the reliability of helium detection. At the same time, the back pressure helium filling and then detection method for the injection hole sealing welding position can more accurately detect whether there is a leak at the aluminum nail welding position, improve the leak detection rate, and thus improve the battery safety.

[0037] In step S5, the second helium detection result is obtained, and the cover plate welding and aluminum nail welding positions are analyzed for leaks. If the helium detection result of the battery cover plate welding position fails, the battery is stored in the NG buffer area, and the cover plate welding process and the injection hole sealing welding process are analyzed to determine the cause of the leak; if the helium detection result of 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 detection result passes, it indicates that the battery is qualified and enters the next station for subsequent processing.

[0038] In an embodiment of the present invention, based on the above-mentioned battery helium detection method, a battery helium detection system is further provided, including:

[0039] The primary helium inspection unit is used to inject helium into the battery after the battery cover is welded, and to perform the first helium inspection on the welding position of the battery cover; the primary helium inspection unit can use 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 by using the existing injection device, and the sealing welding of the injection hole can also be welded by existing technology, such as laser welding, etc.;

[0041] The back pressure helium filling unit is used to perform back pressure helium filling at the injection hole position; the back pressure helium filling unit is arranged at the back pressure helium filling station, and includes a sealing helium pressing mechanism arranged above the station, and the end of the sealing helium pressing mechanism is provided with a sealing ring. During back pressure helium filling, the end of the sealing helium pressing mechanism is aligned with the injection hole and moves downward until the sealing ring is in close contact with the battery injection hole position, and then the injection hole position is back pressure filled with helium according to the preset pressure and pressure holding time;

[0042] Secondary helium inspection unit, used to conduct a second helium inspection on the welding position of the battery cover and the sealing welding position of the injection hole;

[0043] The analysis unit is used to determine whether the battery is qualified according to the second helium detection result.

[0044] In some embodiments, a transplanting tray is further included, on which a plurality of battery installation tools are provided for fixing the battery in a position with the injection hole facing upward and realizing the transfer of the battery between various workstations.

[0045] In some embodiments, a robot is also included to realize the transfer of batteries between various workstations and loading and unloading of materials.

[0046] In some embodiments, 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, the batteries are grabbed by a robot in the unloading area and transferred to the NG buffer area for subsequent process analysis.

[0047] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A battery helium detection method, characterized in that: include: After the battery cover is welded, helium is injected into the battery to perform the first helium detection on the welding position of the battery cover; After the first helium test is passed, electrolyte and helium are injected into the battery, and then the injection hole is sealed and welded; Perform back pressure helium filling at the injection hole position; Conduct a second helium test on the battery cover welding position and the injection hole sealing welding position; Determine whether the battery is qualified based on the second helium test result.

2. A battery helium detection method as claimed in claim 1, characterized in that: The sealing welding of the injection hole comprises inserting a glue nail into the injection hole for sealing, and welding an aluminum nail at the injection hole to seal the injection hole.

3. A battery helium detection method as claimed in claim 2, characterized in that: The aluminum nail welding position at the injection hole is back-pressure filled with helium. If there is a leak at the aluminum nail welding position, helium is injected into the gap between the aluminum nail and the rubber nail through the leak.

4. A battery helium detection method as claimed in claim 3, characterized in that: The battery is placed with the injection hole facing upwards, and a sealed helium pressure mechanism is provided at the back pressure helium filling station. A sealing ring is provided at the end of the sealed helium pressure mechanism. The end of the sealed helium pressure mechanism is aligned with the injection hole and moves downward until the sealing ring is in close contact with the battery injection hole, and then back pressure helium filling is carried out.

5. A battery helium detection method as claimed in claim 1, characterized in that: The second helium detection of the battery cover welding position and the injection hole sealing welding position includes: placing the battery in a helium detection cavity, evacuating the helium detection cavity, and then performing helium leakage detection on the battery cover welding position and the injection hole sealing welding position at the same time.

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

7. A battery helium detection system, characterized in that: include: The primary helium inspection unit is used to inject helium into the battery after the battery cover is welded, and to perform the first helium inspection on the welding position of the battery cover; A sealing unit, used to inject electrolyte and helium into the battery after the first helium test is passed, and then seal and weld the injection hole; A back pressure helium filling unit is used to fill the injection hole with helium under back pressure; Secondary helium inspection unit, used to conduct a second helium inspection on the welding position of the battery cover and the sealing welding position of the injection hole; The analysis unit is used to determine whether the battery is qualified according to the second helium detection result.

8. A battery helium detection system as claimed in claim 7, characterized in that: It also includes a transplanting tray, on which are provided a plurality of battery installation tools for fixing the battery in a position with the injection hole facing upward, and realizing the transfer of the battery between various workstations.

9. A battery helium detection system as claimed in claim 7, characterized in that: It also includes a robot for transferring batteries between various workstations and loading and unloading materials.

10. A battery helium detection system as claimed in claim 7, characterized in that: The back-pressure helium filling unit comprises a sealed helium pressing mechanism, and a sealing ring is provided at the end of the sealed helium pressing mechanism. During back-pressure helium filling, the end of the sealed helium pressing mechanism is aligned with the injection hole and moves downward until the sealing ring is in close contact with the position of the battery injection hole, and then the injection hole is back-pressure filled with helium according to the preset pressure and pressure holding time.

Images