Process for processing tab easy break zone and lithium ion battery

Abstract

The application discloses a kind of processing tab easy folding area's process method and lithium ion battery, process method includes: the height detection of the exposed tab rubber of top seal after electric core, if the height H of tab rubber meets preset numerical range, then carry out next step processing;With one side of tab as A surface, the other side is B surface, by laser, the tab rubber of A surface is cleaned and removed, so that the tab rubber of A surface meets the requirement of preset height h1;By laser, the tab rubber of B surface is cleaned and removed, and the tab rubber area of B surface is cleaned out without tab rubber to provide tab exposed avoidance area, so that the upper and lower sides of the avoidance area all exist tab rubber, and the tab rubber of lower side of the avoidance area meets the requirement of preset height h1.The application is beneficial to keep the exposed height of tab rubber consistent, facilitate to control the bending height after tab and PCB board welding, and is beneficial to improve production yield.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery production, in particular to a process method for processing an easy folding area of a tab and a lithium ion battery. BACKGROUND

[0002] Lithium ion batteries are widely used in energy storage, 3C, new energy vehicles and other fields due to their high energy density, long cycle life, high platform voltage and good safety performance. In the production process, the cell of the lithium ion battery needs to be top-sealed using tab sealant. The height of the tab sealant after top-sealing is not consistent, which leads to poor height consistency of the tab sealant of the cell after top-sealing. On the other hand, the tab needs to be bent after being welded to the PCB. The bending line of the tab needs to be outside the tab sealant to avoid the influence of the tension and rebound force of the tab sealant on the bending of the tab. Due to the inconsistent height of the tab sealant, it is difficult to control the position of the bending line, which leads to a large deviation in the bending height of the tab after being welded to the PCB, resulting in the generation of defective products and reducing the yield of good products. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a process method for processing an easy folding area of a tab. The tab sealant after top-sealing is cleaned by laser to clean out an avoidance area, which is conducive to keeping the exposed height of the tab sealant consistent and controlling the position of the bending line of the tab after being welded to the PCB in the avoidance area, thereby controlling the bending height of the tab after being welded to the PCB.

[0004] The present application also provides a lithium ion battery prepared by the process method for processing an easy folding area of a tab.

[0005] The process method for processing an easy folding area of a tab according to the first aspect of the present application comprises the following steps:

[0006] S1, height detection: detecting the height of the tab sealant exposed after top-sealing of the cell. If the height H of the tab sealant meets the preset value range, the next step of processing is performed.

[0007] S2, A surface cleaning: taking one side of the tab as the A surface and the other side as the B surface, the tab sealant on the A surface is cleaned by laser to meet the requirement of the preset height h1.

[0008] S3, B surface cleaning: the tab sealant on the B surface is cleaned by laser to clean out an avoidance area without tab sealant for the tab to be exposed, so that the upper and lower sides of the avoidance area have tab sealant and the tab sealant on the lower side of the avoidance area meets the requirement of the preset height h1.

[0009] The process method for processing the easy-bending area of the tab has at least the following beneficial effects: the laser cleaning of the tab gel on the two surfaces of the tab after the top sealing facilitates keeping the exposed height of the tab gel consistent, and the absence of tab gel in the avoidance area facilitates easier bending, the position of the bending line can be controlled in the avoidance area when the tab is bent after the welding with the PCB, facilitating the control of the bending height of the tab after the welding with the PCB, facilitating the improvement of the production yield, and further cleaning the excess tab gel downward to reduce the bending line height, thereby facilitating the improvement of the battery capacity.

[0010] According to some embodiments of the present application, in step S1, a preset height h2 is set, and a preset value range is configured as: h1

[0011] According to some embodiments of the present application, in step S2 and / or step S3, the tab gel on the corresponding surface of the tab is cleaned at least twice by laser.

[0012] According to some embodiments of the present application, the tab gel on the corresponding surface of the tab is cleaned twice by laser.

[0013] According to some embodiments of the present application, the tab gel is cleaned by laser with a preset power P1 the first time and with a preset power P2 the second time, the preset power P1 is in the range of 60-200W, and the preset power P2 is in the range of 60-200W.

[0014] According to some embodiments of the present application, the first laser cleaning is performed at a preset speed V1, and the second laser cleaning is performed at a preset speed V2, the preset speed V1 is in the range of 500-4000mm / s, and the preset speed V2 is in the range of 500-4000mm / s.

[0015] According to some embodiments of the present application, in step S2 and / or step S3, inert gas is filled for protection during the laser cleaning of the tab gel.

[0016] According to some embodiments of the present application, in step S2 and / or step S3, a negative pressure dust removal device is used to remove the dust generated during the cleaning process.

[0017] The lithium ion battery according to the second aspect of the embodiments of the present application is manufactured by the process method for processing the easy-bending area of the tab according to the first aspect of the embodiments of the present application.

[0018] The lithium ion battery according to the embodiment of the present application has at least the following beneficial effects: by using the above process, the bending height of the tab after welding with the PCB can be controlled, the production yield can be improved, and the folding line height of the tab after welding with the PCB can be reduced, and the reduced height can be given to the main body of the battery cell, so as to increase the capacity of the battery cell and improve the capacity of the battery cell.

[0019] Additional aspects and advantages of the present application will be described in the following description, will become apparent from the following description, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 A simple flowchart of the process method of the embodiment of the present application is shown in the figure;

[0022] Figure 2 A structure diagram of the battery cell processed in the process method of the embodiment of the present application is shown in the figure;

[0023] Figure 3 A comparison diagram of the tab A surface of the battery cell before and after processing in step S2 is shown in the figure; Figure 2

[0024] A comparison diagram of the tab B surface of the battery cell before and after processing in step S3 is shown in the figure; Figure 4 Figure 2 A structure diagram of the tab B surface of the battery cell after processing in step S3 is shown in the figure;

[0025] Figure 5 Figure 2 A structure diagram of the tab B surface of the battery cell after processing in step S3 is shown in the figure;

[0026] Figure 6 A diagram showing the residual level of the tab adhesive after laser cleaning is shown in the figure;

[0027] Figure 7 A diagram showing the cleaning effect of the tab adhesive of the battery cell with an 80-micron tab adhesive thickness using different preset powers for laser cleaning in the process method of the present application is shown in the figure;

[0028] Figure 8 A diagram showing the cleaning effect of the tab adhesive of the battery cell with a 55-micron tab adhesive thickness using different preset powers for laser cleaning in the process method of the present application is shown in the figure;

[0029] Figure 9 A diagram showing the damage of the tab using different preset speeds for laser cleaning in the process method of the present application is shown in the figure.

[0030] REFERENCE NUMERALS: ​​

[0031] Tab 10, tab adhesive 20, empty area 21, height H, preset height h1, distance size D. DETAILED DESCRIPTION

[0032] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only for the purpose of explaining the present application, and cannot be understood as a limitation of the present application.

[0033] In the description of the present application, it should be understood that, if the orientation description is involved, for example, the orientation or position relationship indicated by the upper, lower, etc. is based on the orientation or position relationship shown in the drawings, which is only for the purpose of facilitating the description of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0034] In the description of the present application, if the words such as several, greater than, less than, more than, above, below, within, etc. appear, wherein the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, more than, etc. is understood as not including the number, above, below, within, etc. is understood as including the number.

[0035] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0036] Reference Figures 1 to 5 A process for processing the tab easy folding area, comprising the following steps:

[0037] S1, height detection: the height of the tab adhesive 20 exposed after the top sealing of the battery cell is detected, if the height H of the tab adhesive 20 meets the preset value range, the next step of processing is performed;

[0038] S2, A surface cleaning: taking one side of the tab 10 as the A surface and the other side as the B surface, the tab adhesive 20 of the A surface is cleaned by laser to make the tab adhesive 20 of the A surface meet the requirement of the preset height h1;

[0039] S3, B surface cleaning: the tab adhesive 20 of the B surface is cleaned by laser, and the empty area 21 for the tab 10 to be exposed is cleaned in the tab adhesive area of the B surface, so that the upper and lower sides of the empty area 21 both have the tab adhesive 20 and the tab adhesive 20 on the lower side of the empty area 21 meets the requirement of the preset height h1.

[0040] In the production process, after the lithium ion battery cell is top-sealed by using the tab sealant, the height of the tab sealant 20 after top-sealing is detected by step S1 to determine the battery cell that needs to be processed; in combination with Figure 3 and Figure 4 The tab sealant 20 on both sides of the tab 10 after top-sealing is cleaned by laser. When the laser cleans the surface of the tab sealant 20, the tab sealant 20 absorbs the laser energy to heat, burn and gasify, so as to be removed. The tab sealant 20 on the A surface and the tab sealant 20 under the avoidance area 21 on the B surface meet the requirement of the preset height h1, which is beneficial to keep the exposed height of the tab sealant 20 at different tabs 10 consistent. In addition, the avoidance area 21 is cleaned without tab sealant 20 on the B surface. Since there is no tab sealant 20 in the avoidance area 21, and there is tab sealant 20 on the upper and lower sides of the avoidance area 21, the tab 10 is more easily bent in the avoidance area 21. When the tab 10 is bent after welding with the PCB, the position of the bending line can be controlled in the avoidance area 21, which is beneficial to control the bending height of the tab 10 after welding with the PCB, and improve the production yield. In addition, the tab sealant 20 can be further cleaned downward to reduce the bending height, thereby improving the capacity of the battery cell.

[0041] Specifically, in the process of step S2 to step S3, the same side laser can clean the A surface and the B surface of the tab 10 by turning over the battery cell, which reduces the setting of the laser and reduces the cost. Of course, the laser can also be arranged on the A surface and the B surface of the tab 10 to clean and remove the tab sealant 20.

[0042] In some embodiments, in step S1, a preset height h2 is set, and the preset value range is configured as: h1 < H ≤ h2. If the height H of the tab sealant 20 meets: h1 < H ≤ h2, step S2 is performed for processing. If the height H of the tab sealant 20 meets: H < h1, it is directly transferred to the next process.

[0043] It can be understood that, referring to Figure 2 In step S1, the height of the tab sealant 20 after top-sealing is not consistent. For the height H of the tab sealant 20 less than the preset height h1, the height of the tab sealant 20 is low, so it does not need to be cleaned and removed, and it can be directly transferred to the next process for processing. By setting the preset height h2, the defective products with high tab sealant 20 height can be directly discarded, and there is no need to process. By setting the range value to screen the tab sealant 20, the battery cell that meets the processing requirement is processed to improve the effective work rate.

[0044] Specifically, in step S1, the height of the exposed tab sealant 20 after top-sealing can be detected by using a CCD area camera.

[0045] In some embodiments, the preset height h1 is in the range of 0.4-1.2 mm, the preset height h2 is in the range of 1.2-2.2 mm, and the distance D between the upper and lower edges of the avoidance area 21 is configured to be 0.1 mm≤D≤0.4 mm. It can be understood that, referring to Figure 4 and Figure 5 , the distance D between the upper and lower edges of the avoidance area 21 (i.e. the height of the avoidance area 21) is in the range of 0.1-0.4 mm, so that the height of the avoidance area 21 is moderate, avoiding the situation that the height is too low to form the bending line or the height is too high to control the position of the bending line, facilitating use.

[0046] In actual application, the preset height h1 can be 0.4 mm, 0.8 mm or 1.2 mm, the preset height h2 can be 1.2 mm, 1.6 mm or 2.2 mm, and the distance D can be 0.1 mm, 0.2 mm, 0.3 mm or 0.4 mm, which can be set according to actual needs.

[0047] In some embodiments, in steps S2 and / or S3, the tab adhesive 20 on the corresponding surface of the tab 10 is cleaned at least twice by laser. It can be understood that, if the tab adhesive 20 on the corresponding surface of the tab 10 is cleaned only once, a larger power laser needs to be used. Since the internal tab 10 can be damaged by the high-power laser during cleaning of the tab adhesive 20 in contact with the tab 10, the laser power or the cleaning power of the corresponding position can be controlled by multiple cleaning to reduce the possibility of damage to the tab 10 during cleaning, facilitating use.

[0048] Specifically, in the present embodiment, the tab adhesive 20 is cleaned and removed by the above method in steps S2 and S3. Of course, in actual application, the above method can also be used only in step S2 or step S3.

[0049] Further, in steps S2 and S3, the tab adhesive 20 on the A surface and the B surface of the tab 10 is cleaned twice by laser. The first laser cleaning is main cleaning of the tab adhesive 20, and the second laser cleaning is auxiliary cleaning of the tab adhesive 20 on the metal part (the part of the front projection coinciding with the tab 10), which can make the surface of the tab 10 free of residual glue and effectively reduce the possibility of damage to the tab 10, avoiding affecting the anti-breaking performance. On the premise of achieving good cleaning effect, the cleaning times are minimized to improve efficiency. Of course, in actual application, three or four times of laser cleaning or more can also be used on the A surface and / or the B surface of the tab 10, which can be set according to actual needs.

[0050] Furthermore, the tab adhesive 20 is cleaned for the first time with a laser of preset power P1, and then cleaned for the second time with a laser of preset power P2. The preset power P1 ranges from 60 to 200W, and the preset power P2 ranges from 60 to 200W. The first laser cleaning is performed at a preset speed V1, and the second laser cleaning is performed at a preset speed V2. The preset speed V1 ranges from 500 to 4000 mm / s, and the preset speed V2 ranges from 500 to 4000 mm / s.

[0051] To confirm the effectiveness of laser cleaning, a 200W laser was used to clean tab adhesive of different thicknesses. A better cleaning effect was indicated by the tab adhesive height after laser cleaning being closer to the set height (0.6mm). Figure 6 The diagram showing the residual adhesive levels of the tabs is shown in the table below. The test results are as follows:

[0052]

[0053]

[0054] Verification and data analysis revealed that the power and speed of laser cleaning are significant factors affecting the tab adhesive after cleaning.

[0055] Experiments were conducted based on different laser powers, with reference to... Figure 7 and Figure 8 Lasers with power ranges of 60, 130, and 200W were used to clean tab adhesive with thicknesses of 80μm and 55μm, and the cleaning results all met the requirements. Regarding the cleaning speed, experiments were conducted at different cleaning speeds, referring to... Figure 9 Cleaning speeds ranging from 500 to 4000 mm / s were used to clean the tab adhesive on different types of tabs. No damage was observed to the tabs, confirming that cleaning speeds within this range do not pose a risk of tab damage when removing the adhesive. Based on experimental data and actual production needs, it was determined that laser power below 60W is insufficient for cleaning the tab adhesive, while power above 200W affects the lifespan of the laser system. Therefore, the parameter range was set to 60-200W. Currently, the laser cleaning speed is 1000-5000 mm / s. Experiments showed that cleaning below 500 mm / s resulted in excessively long cleaning times, failing to meet cleaning efficiency requirements. Therefore, the lower limit of the speed was set to 500 mm / s. Speeds above 4000 mm / s resulted in residue buildup, affecting the cleaning effect. Therefore, the parameter range was set to 500-4000 mm / s.

[0056] Specifically, in the present embodiment, when cleaning the outer surface of the tab adhesive 20 for the first time, a high-power laser with a wave shape No. 1, a frequency of 10 kHz, a power of 70 W, and a line spacing of 0.05 mm is used for main cleaning to burn and gasify the outer surface of the tab adhesive 20; when cleaning the tab adhesive 20 of the metal part (the part whose front projection coincides with the tab 10) for the second time, a low-power laser with a wave shape No. 2, a frequency of 10 kHz, a power of 60 W, and a line spacing of 0.05 mm is used for auxiliary cleaning to clean the remaining tab adhesive 20 liquid and the suspended part after the first cleaning, while avoiding damaging the tab 10 by the laser, and clean the remaining tab adhesive 20 completely.

[0057] In some embodiments, in step S2 and / or step S3, inert gas is filled for protection during laser cleaning of the tab adhesive 20. Inert gas needs to be added for protection during cleaning, which mainly plays a role in preventing oxidation and reducing temperature, and improves processing reliability.

[0058] In some embodiments, in step S2 and / or step S3, a negative pressure dust removal device is used to remove the dust generated during cleaning of the tab adhesive 20. This can avoid dust adhering to the tab 10 and causing pollution, and improve processing reliability. In actual application, the negative pressure dust removal device can be a negative pressure fan or a vacuum pump or other device with suction capacity, which can be set according to actual needs.

[0059] It should be further noted that, in the above process, the tab adhesive 20 can be one of white tab adhesive 20, yellow tab adhesive 20, or black tab adhesive 20, the laser used for cleaning the tab adhesive 20 can be one of a gas laser, a solid laser, or a semiconductor laser, the number of tabs on the processed battery cell can be two tabs, three tabs, or four tabs, and the tab 10 can be an aluminum tab, a nickel tab, or a copper-nickel-plated tab, which can be set according to actual needs.

[0060] The lithium ion battery according to the second aspect of the present application is manufactured by using the process for processing the tab easy-to-fold area according to the first aspect of the present application.

[0061] The lithium ion battery according to the embodiments of the present application is manufactured by using the above process, which is beneficial to controlling the folding height of the tab 10 after welding with the PCB, improving the production yield, and reducing the folding line height of the tab 10 after welding with the PCB. The reduced height can be given to the battery cell body, thereby increasing the capacity of the battery cell and improving the capacity of the battery cell.

[0062] Since other components of the lithium ion battery according to the embodiments of the present application are known to those skilled in the art, they will not be described in detail here.

[0063] The embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application.

Claims

1. A process for processing a tab easy fold region, characterized by, The method comprises the following steps: S1, height detection: detecting the height of the exposed tab rubber after the top sealing of the battery cell, setting preset heights h1 and h2, if the height H of the tab rubber meets: h1 < H ≤ h2, then the next step processing is performed, if the height H of the tab rubber meets: H ≤ h1, then it is directly transferred to the next process; S2, A surface cleaning: taking one side of the tab as the A surface and the other side as the B surface, the tab rubber on the A surface is cleaned by laser to meet the requirement of the preset height h1; S3, B surface cleaning: the tab rubber on the B surface is cleaned by laser to clean the tab rubber area on the B surface to form an empty area for the tab to expose, and the upper and lower sides of the empty area have tab rubbers and the tab rubber on the lower side of the empty area meets the requirement of the preset height h1. In step S2 and / or step S3, the dust generated in the process of laser cleaning of the tab rubber is removed by a negative pressure dust removal device.

2. The process for processing the tab easy fold zone of claim 1, wherein, In step S2 and / or step S3, the tab rubber on the corresponding surface of the tab is cleaned by laser at least twice.

3. The process for processing the tab easy fold zone of claim 2, wherein, The tab rubber on the corresponding surface of the tab is cleaned by laser twice.

4. The process for processing the tab easy fold zone of claim 3, wherein, The first time, the tab rubber is cleaned by laser with a preset power P1, and the second time, the tab rubber is cleaned by laser with a preset power P2, the value range of the preset power P1 is 60-200W, and the value range of the preset power P2 is 60-200W.

5. The process for processing the tab easy fold zone of claim 3, wherein, The first time, the laser cleaning is performed at a preset speed V1, and the second time, the laser cleaning is performed at a preset speed V2, the value range of the preset speed V1 is 500-4000mm / s, and the value range of the preset speed V2 is 500-4000mm / s.

6. The process for processing the tab easy fold zone of claim 1, wherein, In step S2 and / or step S3, inert gas is filled for protection during the laser cleaning of the tab rubber.

7. A lithium-ion battery, characterized by The method is manufactured by using the process method for processing the tab easy folding area according to any one of claims 1 to 6.

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