A method of welding a seal pin of a lithium-ion battery

Abstract

The application provides a welding method of a sealing nail of a lithium ion battery. The welding method comprises the following steps: in an air environment, transmitting a welding track of the sealing nail to a continuous laser welding device by using a CCD system, sequentially performing first welding and second repairing welding on the sealing nail, and obtaining the lithium ion battery with the welded sealing nail; wherein, the welding track of the second repairing welding is consistent with the welding track of the first welding; the continuous laser welding device comprises a galvanometer and an adjustable annular light spot structure. In the welding method provided by the application, no protective gas is added throughout the whole process, the CCD system and the welding process work together, the welding time is shortened, the welding effect is good, the number of appearance inspection workers and the labor intensity are reduced, the cost is saved, and the purpose of reducing the number of employees and increasing efficiency is achieved.

Description

Technical Field

[0001] This invention belongs to the field of battery sealing technology and relates to a welding method for sealing pins of lithium-ion batteries. Background Technology

[0002] Lithium-ion batteries are power sources that provide power to power tools. They are widely used in various fields due to their advantages such as long lifespan, practicality, safety, large capacity, small size, and light weight. As a type of new energy source, lithium-ion batteries are widely used in our lives, and aluminum-cased batteries are among the most widely used lithium-ion battery types due to their safety advantages.

[0003] Sealing nail welding is a crucial component of battery cells and is the final laser welding process in lithium battery cell production. Therefore, the yield rate of this process is of paramount importance, as scrapping products at the final stage results in significant cost losses for battery manufacturers.

[0004] Currently, most battery manufacturers in the new energy industry use YAG pulse welding equipment for sealing nail welding processes. This is because YAG lasers, equipped with arbitrary waveform real-time energy negative feedback technology, possess excellent single-pulse energy stability, ultimately achieving a first-pass welding success rate of ≥99.5%. However, YAG lasers are not without their limitations. Their power has an upper limit; the maximum power currently available on the market is 600W. This power limitation restricts the welding frequency, forcing the current practice to use a collimated head for pulse welding.

[0005] In the welding process of sealing nails, a collimating head pulse spot welding + coaxial blowing of protective gas is used to complete the welding path through a CNC worktable. Protective gas is blown during laser welding to ensure that the product can control the generation of welding spatter and molten beads after laser welding, resulting in a more aesthetically pleasing, delicate, and whitish appearance. Ultimately, a first-pass welding success rate of ≥99.5% can be achieved. For example, CN108714747A discloses a sealing nail welding inspection system, including: a positioning mechanism, a welding mechanism, and an inspection mechanism; the positioning mechanism is located on the side of the welding mechanism and is used to place the sealing nail at the assembly position on the battery; the welding mechanism includes: a first driving component, a welding head, and a protective device; the connecting end of the welding head is rotatably disposed at the actuating end of the first driving component; the connecting end of the protective device is connected to the laser emitting end of the welding head and is used to blow protective gas onto the welding area; and the protective device is coaxially arranged with the welding head; the inspection mechanism is used to detect whether the welding of the sealing nail is qualified.

[0006] However, during the welding process, the shielding gas can interfere with the extrusion forming of the laser weld, affecting the quality of the weld product, the depth and width of the weld pool in butt welds. In most cases, blowing in the shielding gas will significantly interfere with the welding process and may have adverse effects.

[0007] Improper shielding gas blowing can cause molten pool spatter during laser welding, leading to shrinkage or even oxidation of the weld pool in butt welds. It can also reduce the effective utilization of the laser beam. Achieving the desired welding blowing effect requires careful selection of the appropriate gas type, pressure, and blowing method, and demands a high level of precision in the implementation process.

[0008] In this welding process, the quality control of the protective gas is extremely prone to defects such as bursts, porosity, cracks, and weld slag. These defects seriously affect the performance of the battery cell and even threaten its safety. In particular, defects such as cracks require manual inspection of each post-weld battery cell under a 30x magnifying glass.

[0009] Therefore, improving the welding quality of sealing pins in lithium-ion power batteries while enhancing their safety performance is an urgent technical problem to be solved. Summary of the Invention

[0010] The purpose of this invention is to provide a welding method for sealing nails in lithium-ion batteries. In this welding method, no protective gas is required throughout the process. The CCD system works synergistically with the welding process, shortening the welding time while achieving excellent welding results. This reduces the number of personnel required for visual inspection and the intensity of labor, saving costs and achieving the goal of reducing manpower and increasing efficiency.

[0011] To achieve this objective, the present invention adopts the following technical solution:

[0012] This invention provides a welding method for sealing pins of lithium-ion batteries, the welding method comprising the following steps:

[0013] In an air environment, a CCD system is used to transmit the welding trajectory of the sealing nail to a continuous laser welding device, and the sealing nail is sequentially subjected to a first welding and a second repair welding to obtain a lithium-ion battery with welded sealing nails;

[0014] The welding trajectory of the second repair weld is consistent with that of the first weld; the continuous laser welding equipment includes a galvanometer and an adjustable annular spot structure.

[0015] The sealing nail in this invention can be made of aluminum.

[0016] The CCD system in this invention is a well-known and unambiguous term in the art, specifically a CCD vision positioning system. This system can determine the position of the sealing nail, and the data results of the obtained image can be directly calculated by the calculation software in the system to obtain the welding trajectory. Furthermore, the CCD system can screen out the battery cell structure where the sealing nail is not installed in place, and the defective battery cell can be removed by a robotic arm.

[0017] The welding method provided by this invention eliminates the need for protective gas throughout the process. The CCD system works in conjunction with continuous laser welding. The galvanometer scanning efficiency and cycle time of the continuous laser welding equipment are high, avoiding the real-time movement required by spot welding. Furthermore, the adjustable annular spot structure, including inner and outer ring structures, increases the output power of the laser welding equipment. A second surface repair weld is performed at the original welding position after the first weld, resulting in a smoother and more delicate surface in the original weld area. This replaces the effect previously achieved by blowing protective gas, thus shortening the welding time while providing excellent welding results and improving the safety performance of lithium-ion batteries. It also eliminates the need for mandatory visual inspection due to the addition of protective gas, reducing the number of manpower required for visual inspection and labor intensity, thereby saving costs.

[0018] In this invention, no protective gas is required during the welding process, which can be achieved in a normal air environment. If a second repair weld is not performed after the first weld, a delicate and smooth appearance cannot be achieved.

[0019] As a preferred technical solution of the present invention, the CCD system first takes a picture of the sealing nail position, calculates the picture data results, and transmits the calculated welding trajectory command to the continuous laser welding equipment.

[0020] The calculation process provided by this invention can be implemented in a CCD system.

[0021] As a preferred technical solution of the present invention, the sealing nail is made of aluminum, and during the first welding process, the inner ring power of the continuous laser welding equipment is 580-630W, such as 580W, 590W, 600W, 610W, 620W or 630W.

[0022] As a preferred technical solution of the present invention, the sealing nail is made of aluminum, and during the first welding process, the outer ring power of the continuous laser welding equipment is 580-630W, such as 580W, 590W, 600W, 610W, 620W or 630W.

[0023] In this invention, the inner ring power and the outer ring power work together to regulate the output power of the laser equipment, reducing the probability of welding explosions. The power ranges of both the inner ring power and the outer ring power must be within the aforementioned value ranges to enable the front end of the outer ring spot to preheat the workpiece, while the central spot is used to form a welding aperture, and the rear end of the outer ring spot is used to stabilize the molten pool. If either is too high or too low, it will lead to defects such as spatter and porosity.

[0024] As a preferred technical solution of the present invention, the welding parameters in the first welding process include the CW mode.

[0025] In this invention, CW mode refers to continuous laser welding mode.

[0026] As a preferred technical solution of the present invention, in the first welding process, the helix spacing in the welding parameters is 0.2 to 0.3 mm, for example, 0.2 mm, 0.23 mm, 0.25 mm, 0.28 mm or 0.3 mm, and the helix diameter is 0.8 to 1 mm, for example, 0.83 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.93 mm, 0.95 mm, 0.98 mm or 1 mm.

[0027] As a preferred technical solution of the present invention, in the first welding process, the galvanometer scanning speed in the welding parameters is 250-400 mm / s, such as 250 mm / s, 280 mm / s, 300 mm / s, 330 mm / s, 350 mm / s, 380 mm / s or 400 mm / s, etc.

[0028] In the first welding process, the present invention adjusts the welding parameters. Within the range of the provided welding parameters, the welding speed can be increased without affecting the welding effect.

[0029] As a preferred technical solution of the present invention, during the second repair welding process, the scanning speed of the galvanometer is 1200-1400 mm / s, for example, 1200 mm / s, 1210 mm / s, 1220 mm / s, 1230 mm / s, 1240 mm / s, 1250 mm / s, 1260 mm / s, 1270 mm / s, 1280 mm / s, 1290 mm / s, 1300 mm / s, 1310 mm / s, 1320 mm / s, 1330 mm / s, 1340 mm / s, 1350 mm / s, 1360 mm / s, 1370 mm / s, 1380 mm / s, 1390 mm / s, or 1400 mm / s.

[0030] As a preferred technical solution of the present invention, the helix spacing in the welding parameters is 0.2 to 0.3 mm, such as 0.2 mm, 0.23 mm, 0.25 mm, 0.28 mm or 0.3 mm, and the helix diameter is 0.8 to 1 mm, such as 0.83 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.93 mm, 0.95 mm, 0.98 mm or 1 mm.

[0031] As a preferred technical solution of the present invention, in the second repair welding process, the outer ring power of the continuous laser welding equipment is 300-330W, such as 300W, 305W, 310W, 315W, 320W, 325W or 330W.

[0032] The second repair welding process provided by this invention uses a combination of low power and high scanning speed to repair the appearance of the welded surface. It performs a fill scan on the area after the first weld, making the surface smoother and more delicate, replacing the original method of blowing protective gas. If high power and high speed are used, that is, if the power is too high, too much energy will be input to the workpiece, causing perforation. If low power and low scanning speed are used, that is, if the scanning speed is too low, the appearance will be rough, thus failing to achieve an effective repair effect.

[0033] As a preferred technical solution of the present invention, dust removal treatment is carried out throughout the welding process.

[0034] As a preferred technical solution of the present invention, the CCD system is used to perform quality inspection on the lithium-ion battery with welded sealing nails.

[0035] In this invention, the CCD system can detect the position of the sealing nails of the lithium-ion battery throughout the welding process and after welding. Based on the obtained photographic results, it can detect good and bad welds. Good welds can proceed to the next processing step, while bad welds can be rejected.

[0036] As a preferred technical solution of the present invention, the welding method includes the following steps:

[0037] In an air environment, the CCD system first takes a picture of the sealing nail position, calculates the picture data results, and transmits the calculated welding trajectory command to the continuous laser welding equipment to perform the first welding of the sealing nail in CW mode with an inner ring power of 580-630W and an outer ring power of 580-630W.

[0038] During the first welding process: the spiral spacing in the welding parameters is 0.2-0.3 mm, the spiral diameter is 0.8-0.1 mm, and the galvanometer scanning speed in the welding parameters is 250-400 mm / s;

[0039] After the first welding is completed, a second repair welding is performed on the welding trajectory of the first welding with an outer ring power of 300-330W and a galvanometer scanning speed of 1200mm / s-1400mm / s to obtain a lithium-ion battery with welded sealing nails. The quality of the lithium-ion battery with welded sealing nails is inspected using a CCD system.

[0040] The continuous laser welding equipment includes a galvanometer and an adjustable annular spot structure, and dust removal is performed simultaneously with welding.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The welding method provided by this invention eliminates the need for protective gas throughout the process. The CCD system works in conjunction with continuous laser welding. The galvanometer scanning efficiency and cycle time of the continuous laser welding equipment are high, avoiding the real-time movement required by spot welding. Furthermore, the adjustable annular spot structure, including inner and outer ring structures, increases the output power of the laser welding equipment. A second surface repair weld is performed at the original welding position after the first weld, resulting in a smoother and more delicate surface in the original weld area. This replaces the effect previously achieved by blowing protective gas, thus shortening the welding time while providing excellent welding results and improving the safety performance of lithium-ion batteries. It also eliminates the need for mandatory visual inspection due to the addition of protective gas, reducing the number of manpower required for visual inspection and labor intensity, thereby saving costs. Attached Figure Description

[0043] Figure 1 This is a top view of the lithium-ion battery that requires sealing nail welding in Example 1.

[0044] Figure 2 This is a welding effect diagram of the sealing nail obtained by the welding method provided in Example 1.

[0045] Figure 3 This is a welding effect diagram of the sealing nail obtained by the welding method provided in Example 5.

[0046] Figure 4 This is a welding effect diagram of the sealing nail obtained by the welding method provided in Example 5.

[0047] Figure 5 This is a diagram showing the welding effect of the sealing nail obtained by the welding method provided in Example 6.

[0048] Figure 6 The image shows the welding effect of the sealing nail obtained by the welding method provided in Comparative Example 1.

[0049] Figure 7 The diagram shows the microcrack situation during the welding process of the welding method provided in Comparative Example 2.

[0050] Figure 8 This is a diagram showing the spatter and molten droplet characteristics during the welding process using the welding method provided in Comparative Example 2.

[0051] Among them, 1-top cover, 2-injection hole, 3-sealing nail, 4-gap between injection hole and sealing nail. Detailed Implementation

[0052] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0053] Example 1

[0054] This embodiment provides a welding method for sealing pins (made of aluminum) of lithium-ion batteries. The specific welding process is as follows:

[0055] In the air environment, sensors are used to detect the battery cells on the conveying device. Then, a CCD device is used to take pictures of the sealing nail positions of the detected battery cells. The image data is transmitted to the background software for calculation. The CCD algorithm software is used to judge whether there are sealing nails and whether the sealing nails are installed in place (for battery cell structures that are not installed in place, a robotic arm is used to remove them). Based on the judgment results, welding trajectory instructions are sent to the continuous laser welding equipment.

[0056] According to the welding trajectory command, the inner ring power of the continuous laser welding equipment is adjusted to 600W and the outer ring power is 600W. The welding parameters adopt CW mode, the spiral filling spacing is 0.3mm and the diameter is 1mm, the galvanometer scanning welding speed is 300mm / s, and the first welding process is carried out according to the above parameters. After the first welding is completed;

[0057] The power of the continuous laser welding equipment was set to 300W, and the scanning speed of the galvanometer was set to 1300mm / s. A second welding repair (appearance repair) was performed on the original welding area of ​​the first welding. After the second welding repair was completed, a dust removal operation was performed, and a good welded product (lithium-ion battery of welded sealing nail) was obtained by CCD detection.

[0058] Figure 1 A top view of the lithium-ion battery requiring sealing nail welding in Example 1 is shown. Figure 1 As can be seen, the liquid injection hole 2 of the top cover 1 of the lithium-ion battery is sealed by sealing nail 3. The gap 4 between the liquid injection hole and the sealing nail is calculated by the CCD system to obtain the welding trajectory.

[0059] Example 2

[0060] This embodiment provides a welding method for sealing pins (made of aluminum) of lithium-ion batteries. The specific welding process is as follows:

[0061] In the air environment, sensors are used to detect the battery cells on the conveying device. Then, a CCD device is used to take pictures of the sealing nail positions of the detected battery cells. The image data is transmitted to the background software for calculation. The CCD algorithm software is used to judge whether there are sealing nails and whether the sealing nails are installed in place (for battery cell structures that are not installed in place, a robotic arm is used to remove them). Based on the judgment results, welding trajectory instructions are sent to the continuous laser welding equipment.

[0062] The inner ring power and outer ring power of the continuous laser welding equipment were both set to 580W. The welding parameters were set to CW mode, with a spiral filler spacing of 0.3mm and a diameter of 1mm. The galvanometer scanning welding speed was 300mm / s. The first welding process was performed based on these parameters. After the first welding was completed...

[0063] The power of the continuous laser welding equipment was set to 310W, the scanning speed of the galvanometer was 1200mm / s, and a spiral filling spacing of 0.3mm and a diameter of 1mm was used. A second welding repair (appearance repair) was performed on the original welding area of ​​the first welding. After the second welding repair was completed, a dust removal operation was performed, and CCD detection was used to find that there were burst points on the appearance.

[0064] Example 3

[0065] This embodiment provides a welding method for sealing pins (made of aluminum) of lithium-ion batteries. The specific welding process is as follows:

[0066] In the air environment, sensors are used to detect the battery cells on the conveying device. Then, a CCD device is used to take pictures of the sealing nail positions of the detected battery cells. The image data is transmitted to the background software for calculation. The CCD algorithm software is used to judge whether there are sealing nails and whether the sealing nails are installed in place (for battery cell structures that are not installed in place, a robotic arm is used to remove them). Based on the judgment results, welding trajectory instructions are sent to the continuous laser welding equipment.

[0067] The inner ring power of the continuous laser welding equipment was set to 630W, the outer ring power to 630W, the welding parameters were set to CW mode, the spiral filling spacing was set to 0.3mm and the diameter to 1mm, the galvanometer scanning welding speed was set to 300mm / s, and the first welding process was carried out according to the above parameters. After the first welding was completed;

[0068] The power of the continuous laser welding equipment was set to 330W, and the scanning speed of the galvanometer was set to 1400mm / s. A second welding repair (appearance repair) was performed on the original welding area of ​​the first welding. After the second welding repair was completed, a dust removal operation was performed, and the welded product (lithium-ion battery of the welded sealing nail) was obtained by CCD detection.

[0069] Example 4

[0070] The difference between this embodiment and Embodiment 1 is that the inner loop power in this embodiment is 500W.

[0071] The remaining welding process and parameters are consistent with those in Example 1.

[0072] Example 5

[0073] The difference between this embodiment and Embodiment 1 is that the outer ring power in this embodiment is 700W.

[0074] The remaining welding process and parameters are consistent with those in Example 1.

[0075] Example 6

[0076] The difference between this embodiment and Embodiment 1 is that the power during the second repair welding process in this embodiment is 500W.

[0077] The remaining welding process and parameters are consistent with those in Example 1.

[0078] Example 7

[0079] The difference between this embodiment and Embodiment 1 is that the scanning speed of the galvanometer during the second repair welding process in this embodiment is 500 mm / s.

[0080] The remaining welding process and parameters are consistent with those in Example 1.

[0081] Comparative Example 1

[0082] The difference between this comparative example and Example 1 is that no second welding repair process is performed during the welding process of this comparative example.

[0083] The welding process and parameters are consistent with those in Example 1.

[0084] Comparative Example 2

[0085] This comparative example provides a process for welding battery sealing nails using a pulse welding method, as detailed below:

[0086] Welding was performed using pulse welding parameters of 6000kV power, 21Hz frequency, welding speed of mm / s, nitrogen gas as shielding gas, and a flow rate of 60L / min.

[0087] Figure 2 The diagram shows the welding effect of the sealing nail obtained by the welding method provided in Example 1. Figure 2 As can be seen, the welding method provided by this invention produces good welding results for the sealing nails, resulting in a smooth and flat surface without cracks or bursts.

[0088] Figure 3 The diagram shows the welding effect of the sealing nail obtained by the welding method provided in Example 5. Figure 3 It can be seen that during the first welding process, the power ranges of the inner ring and the outer ring were not matched, resulting in a burst point during the welding process.

[0089] Figure 4 The diagram shows the welding effect of the sealing nail obtained by the welding method provided in Example 5. Figure 4 It can be seen that; Figure 5 The diagram shows the welding effect of the sealing nail obtained by the welding method provided in Example 6. Figure 4 and Figure 5 It can be seen that during the second repair welding process, the failure to use a combination of low power and high scanning speed resulted in surface roughness and a rough appearance.

[0090] Figure 6 The diagram shows the welding effect of the sealing nail obtained by the welding method provided in Comparative Example 1. Figure 6 It can be seen that without a second repair welding process, the welded surface is relatively rough and cannot achieve a smooth and delicate appearance.

[0091] Figure 7 The diagram shows the microcrack situation during the welding process of the welding method provided in Comparative Example 2; Figure 8 The diagram shows the spatter and molten droplet characteristics during the welding process using the welding method provided in Comparative Example 2. Figure 7 It can be seen that when sealing nails are welded using pulse welding under a protective atmosphere, large-scale bursts and obvious microcracks will occur, resulting in poor welding quality.

[0092] The yield of lithium-ion batteries with welded sealing nails provided in Examples 1-7 and Comparative Example 1 was statistically analyzed. The statistical results are shown in Table 1. Table 1 also shows the burst rate during the first welding process and whether cracks occurred during the welding process (the corresponding defects can be directly observed).

[0093] Table 1

[0094]

[0095]

[0096] The data results from Examples 1, 4, and 5 show that the inner ring power and the outer ring power work together during the first welding process to achieve the depth of the molten pool and a smooth appearance.

[0097] The data results from Examples 1, 6, and 7 show that during the second repair welding process, excessive power (i.e., high power and high scanning speed) is not conducive to a smooth appearance; while insufficient scanning speed (i.e., low power and low scanning speed) will result in a rough surface.

[0098] As can be seen from the data results of Example 1 and Comparative Example 1, a smooth and delicate appearance cannot be obtained without a second repair welding process.

[0099] As can be seen from the data results of Example 1 and Comparative Example 2, the welding method provided by the present invention is less prone to welding cracks and has a better welding effect compared with the conventional pulsed laser welding method that introduces shielding gas. It reduces the cost of shielding gas input, and also reduces the cost of manpower and equipment input for post-weld inspection. At the same time, it achieves better welding effect quality and efficiency, thus achieving the goal of reducing manpower and increasing efficiency.

[0100] In summary, the welding method provided by this invention eliminates the need for protective gas throughout the entire process. The CCD system works in conjunction with continuous laser welding, and the galvanometer scanning efficiency and cycle time of the continuous laser welding equipment are high, avoiding the defects of spot welding that require real-time movement. Furthermore, the adjustable annular spot structure, including inner and outer ring structures, increases the output power of the laser welding equipment. After the first weld, a second surface repair weld is performed at the original weld location, resulting in a smoother and more delicate surface in the original weld area. This replaces the effect previously achieved by blowing protective gas, thus shortening the welding time while providing excellent welding results and improving the safety performance of lithium-ion batteries. It also eliminates the need for a mandatory visual inspection process due to the addition of protective gas, reducing the number of manpower required for visual inspection and labor intensity, thereby saving costs.

[0101] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A welding method for sealing pins in a lithium-ion battery, characterized in that, The welding method includes the following steps: In an air environment, a CCD system is used to transmit the welding trajectory of the sealing nail to a continuous laser welding device, and the sealing nail is sequentially subjected to a first welding and a second repair welding to obtain a lithium-ion battery with welded sealing nails; The welding trajectory of the second repair weld is consistent with that of the first weld; the continuous laser welding equipment includes a galvanometer and an adjustable annular spot structure. The adjustable annular light spot structure includes an inner ring structure and an outer ring structure; During the first welding process, the inner ring power of the continuous laser welding equipment is 580~630W, and the outer ring power is 580~630W. During the second repair welding process, the outer ring power of the continuous laser welding equipment is 300~330W, and the scanning speed of the galvanometer is 1200~1400mm / s.

2. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, The CCD system first takes a picture of the sealing nail position, calculates the picture data, and transmits the calculated welding trajectory command to the continuous laser welding equipment.

3. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, The sealing nail is made of aluminum.

4. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, During the first welding process, the welding parameters include the CW mode.

5. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, During the first welding process, the spiral spacing in the welding parameters is 0.2~0.3mm, and the spiral diameter is 0.8~1mm.

6. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, During the first welding process, the galvanometer scanning speed in the welding parameters is 250~400mm / s.

7. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, During the second repair welding process, the spiral spacing in the welding parameters is 0.2~0.3mm, and the spiral diameter is 0.8~1mm.

8. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, Dust removal is carried out throughout the entire welding process.

9. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, The CCD system was used to perform quality inspection on the lithium-ion batteries with welded sealing nails.

10. The welding method for the sealing pin of a lithium-ion battery according to claim 1, characterized in that, The welding method includes the following steps: In an air environment, the CCD system first takes a picture of the sealing nail position, calculates the picture data results, and transmits the calculated welding trajectory command to the continuous laser welding equipment to perform the first welding of the sealing nail in CW mode with an inner ring power of 580~630W and an outer ring power of 580~630W. During the first welding process: the spiral spacing in the welding parameters is 0.2~0.3mm, the spiral diameter is 0.8~1mm; the galvanometer scanning speed is 250~400mm / s; After the first welding is completed, a second repair welding is performed on the welding trajectory of the first welding with an outer ring power of 300~330W and a galvanometer scanning speed of 1200mm / s~1400mm / s to obtain the lithium-ion battery with welded sealing nails. The lithium-ion battery with welded sealing nails is then inspected for quality using a CCD system. The continuous laser welding equipment includes a galvanometer and an adjustable annular spot structure, and dust removal is performed simultaneously with welding.

Images