Battery cell surface insulating layer jet printing method

Abstract

The invention discloses a battery cell surface insulating layer jet printing method which comprises the following steps: S1, pretreatment: performing texturing treatment on the surface of a battery cell by adopting flat-top laser, synchronously performing dust removal treatment, and then performing plasma cleaning treatment on the battery cell with the textured surface; s2, confirming a jet printing area: identifying and positioning the jet printing area on the surface of the battery cell by adopting visual positioning equipment; s3, jet printing: carrying out jet printing and curing on the jet printing area so as to jet-print an insulating layer on the surface of the battery cell to obtain a jet-printed battery cell; and S4, detection: detecting the jet-printed battery cell to judge whether the jet-printed battery cell reaches the standard or not. According to the invention, the roughness and efficiency of the texturing treatment on the surface of the battery cell are improved through the pretreatment process, so that the adhesive force of the surface of the battery cell is improved, the aluminum powder on the surface of the battery cell is thoroughly removed, the appearance defects of white spots, hard spots and the like on the surface of the battery cell subjected to jet printing of the insulating layer are avoided, and the insulation and pressure resistance and shear strength of the insulating layer are improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery production technology, and in particular to a method for printing an insulating layer on the surface of a battery cell. Background Art

[0002] The traditional surface treatment process for square cells is the coating process, which is to achieve the purpose of insulation by coating the surface of the square cell with PET film and sticking an insulating cover plate. However, the traditional coating process has the following defects: the overall performance of the PET film is poor, the flame retardant performance is low, the heat deformation temperature is low, the shear force and pull-out force between the PET film and the cell are low, and it cannot meet the CTP / CTB trend for the high shear strength of the cell surface; the coated cell has a high risk of failure after long-term use and storage; the coating process has a low yield, especially as the size of the cell increases, the coating process is prone to defects such as bubbles, foreign matter under the film, wrinkles, etc., which greatly increases the production cost and labor cost.

[0003] To this end, the existing technology uses a method of spraying an insulating layer on the surface of the battery cell to improve the strength. However, directly spraying the insulating layer on the surface of the battery cell is prone to white spots and pitting on the surface of the battery cell, thereby affecting the shear strength and insulation withstand voltage performance of the insulating layer. Summary of the invention

[0004] In order to solve the above-mentioned defects in the prior art, the purpose of the present application is to provide a method for printing an insulating layer on the surface of a battery cell, which improves the roughness and efficiency of the roughening treatment on the surface of the battery cell through a pre-treatment process, thereby improving the adhesion of the surface of the battery cell and ensuring that the aluminum powder on the surface of the battery cell is completely removed, thereby avoiding the appearance defects such as white spots and pitting on the surface of the battery cell after printing the insulating layer, and improving the insulation withstand voltage performance and shear strength of the insulating layer.

[0005] The present application provides a method for printing an insulating layer on the surface of a battery cell, comprising the following steps:

[0006] S1. Pre-treatment: Use flat-top laser to roughen the surface of the battery cell and remove dust simultaneously, and then perform plasma cleaning on the battery cell with the roughened surface;

[0007] S2. Confirm the printing area: Use visual positioning equipment to identify and locate the printing area on the surface of the battery cell;

[0008] S3, printing: performing printing and curing on the printing area to print an insulating layer on the surface of the battery cell to obtain a printed battery cell;

[0009] S4. Testing: Test the printed cells to determine whether they meet the standards.

[0010] As a preferred embodiment, in the present application, in step S1, the roughening treatment adopts a flat-top laser flying process, the laser galvanometer of the laser used to provide the flat-top laser is fixed, the flat-top laser is emitted linearly in a specific direction and with specific energy, and the battery cell moves along a preset path so that its surfaces are roughened in turn, and specific areas of the battery cell are avoided, and the specific area includes at least one of the battery cell's poles, QR codes, explosion-proof valves, and the blank areas surrounding the three.

[0011] As a preferred embodiment, in the present application, a visual positioning device is used to identify specific areas of the battery cell and transmit the identification to a control system, so that the control system can control the texturing process to avoid the specific areas.

[0012] As a preferred embodiment, in the present application, in step S1, the dust removal treatment adopts a negative pressure dust extraction method, and the negative pressure dust suction nozzle of the dust removal equipment is aimed at the roughened surface of the battery cell, and the negative pressure dust suction nozzle is flat.

[0013] As a preferred embodiment, in the present application, in step S1, a plasma gas flow is blown toward the roughened surface of the battery cell to perform a plasma cleaning treatment on the battery cell.

[0014] As a preferred embodiment, in the present application, in step S3, the printing area is printed and cured multiple times by combining top spraying, side spraying and edge spraying to print an insulating layer on the surface of the battery cell to obtain a printed battery cell.

[0015] As a preferred embodiment, in the present application, each printing and curing process includes printing, pre-curing and final curing performed in sequence, and the light intensity of the final curing is greater than the light intensity of the pre-curing.

[0016] As a preferred implementation, in the present application, in step S4, the inspection process includes appearance inspection, insulation layer thickness inspection, shear performance and insulation withstand voltage performance inspection.

[0017] As a preferred embodiment, in the present application, in step S1, before plasma cleaning, the battery cell with a roughened surface is subjected to at least one negative pressure dust removal treatment, the dust removal nozzle of the negative pressure dust removal equipment is aligned with the roughened surface of the battery cell, and the dust removal nozzle is a flared structure.

[0018] As a preferred embodiment, in the present application, a rolling step is further included before step S1, in which a rolling device is used to roll the edges of the battery cell, welding slag and burrs on the surface of the battery cell to make the surface of the battery cell smooth.

[0019] As a preferred embodiment, in the present application, a screening step is further included between the rolling step and step S1, and a visual inspection device is used to identify the surface of the battery cell to screen out defective products.

[0020] The method for printing the insulating layer on the surface of a battery cell provided in this application has the following technical effects:

[0021] In the pre-treatment process, the roughening treatment of the cell surface is carried out by a flat-top laser. The center energy of the flat-top laser is the same as the edge energy, which can evenly roughen the cell surface and avoid damage to the cell surface, thereby improving the efficiency and roughness of the cell surface roughening treatment, and ensuring the consistency of the roughness, which is beneficial to improving the adhesion of the cell surface. The cell surface roughening treatment and dust removal treatment are carried out simultaneously, which can remove the aluminum powder generated by the roughening treatment in time, and then cooperate with the subsequent plasma cleaning treatment to ensure that the aluminum powder on the cell surface is completely removed, so that after the printing area on the cell surface is printed and cured to obtain the insulation layer, it can avoid the appearance defects such as white spots and pitting on the cell surface, and improve the insulation withstand voltage performance and shear strength of the insulation layer. DETAILED DESCRIPTION

[0022] For better understanding and implementation, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0023] In the description of the present application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0025] The present application provides a method for printing an insulating layer on the surface of a battery cell, which is an automated process. By developing an automated control program, after setting parameters, the control system is used to control the orderly progress of each step. Based on this, the printing method includes the following steps:

[0026] S1. Pre-treatment: Use flat-top laser to roughen the surface of the battery cell and remove dust simultaneously, and then perform plasma cleaning on the battery cell with the roughened surface;

[0027] S2. Confirm the printing area: Use visual positioning equipment to identify and locate the printing area on the surface of the battery cell;

[0028] S3, printing: performing printing and curing on the printing area to print an insulating layer on the surface of the battery cell to obtain a printed battery cell;

[0029] S4. Testing: Test the printed cells to determine whether they meet the standards.

[0030] In step S1, the purpose of roughening the surface of the battery cell is to remove the oil, electrolyte, oxide layer, etc. that may exist on the surface of the battery cell, and to increase the roughness and adhesion of the surface of the battery cell. The prior art generally adopts three means, namely sandblasting, chemical treatment and laser roughening. For sandblasting, it increases the roughness of the surface of the battery cell by sandblasting, but the sand blasting sand is difficult to control and it is difficult to ensure the consistency of the surface treatment of the battery cell; and it is difficult to accurately avoid the pole, explosion-proof valve and QR code on the pole surface of the battery cell before sandblasting, and it is necessary to increase the cover plate shielding, which complicates the sandblasting process; in addition, the sand is a consumable material and has the defect of high energy consumption. For chemical treatment, it increases the roughness of the surface of the battery cell through the corrosive and oxidizing properties of the chemical solution, but the chemical treatment is more polluting, and the surface of the battery cell needs to be dried and heated. The whole process is difficult to control, and it is difficult to accurately avoid the pole, explosion-proof valve and QR code on the pole surface of the battery cell.

[0031] Compared with the defects of sandblasting, such as poor consistency of surface roughness of battery cells, inability to accurately avoid gaps on the battery cell pole surface, complex process, high energy consumption, and chemical treatment, which is highly polluting, complicated process due to drying, and inability to accurately avoid gaps on the battery cell pole surface, the texturing treatment in this application adopts a laser texturing treatment process, which can not only accurately avoid gaps on the battery cell pole surface, but also has a simple process, no pollution, low energy consumption, and is beneficial to improving the consistency of the surface roughness of the battery cell.

[0032] As for laser roughening, the existing technology generally uses Gaussian laser for roughening, and the poles, explosion-proof valves and QR codes on the pole surface of the battery cell are avoided by scanning the contour of the Gaussian laser. However, Gaussian laser has the characteristics of high center energy and low edge energy. When roughening the surface of the battery cell, the center energy is higher than the damage threshold of the battery cell surface, which can easily cause damage to the surface of the battery cell. The edge energy is lower than the cleaning threshold of pollutants such as oil, electrolyte, and oxide layer, resulting in the edge energy being unable to completely remove pollutants on the surface of the battery cell. In addition, the high center energy of the Gaussian laser can easily produce tiny burrs on the surface of the battery cell, thereby reducing the insulation withstand voltage performance and shear strength after the insulation layer is printed. The roughening treatment of the cell surface in this application uses a flat-top laser. The center energy of the flat-top laser is the same as the edge energy and the energy is moderate. It can evenly roughen the cell surface and completely remove oil, electrolyte, oxide layer and other pollutants on the cell surface. The amount of aluminum powder produced is small and damage to the cell surface is avoided, thereby improving the efficiency and roughness of the cell surface roughening treatment, and ensuring the consistency of roughness, which is conducive to improving the adhesion of the cell surface. In addition, the flat-top laser roughening treatment will not produce tiny burrs on the cell surface, thereby ensuring the insulation withstand voltage performance and shear strength after the printing of the insulation layer.

[0033] While the flat-top laser roughening treatment is being performed, the present application also performs dust removal treatment on the roughened position on the surface of the battery cell, which can remove the aluminum powder generated by the roughening treatment in time. Combined with the plasma cleaning treatment, it can ensure that the aluminum powder on the surface of the battery cell is completely removed, thereby avoiding the appearance defects such as white spots and pitting on the surface of the battery cell after the insulation layer is printed, and improving the insulation withstand voltage performance and shear strength of the insulation layer.

[0034] In step S2, the visual positioning device can be a common CCD visual positioning device on the market. After the surface of the battery cell is pre-treated, the battery cell is conveyed to the printing machine. The CCD visual positioning device is set on the printing machine, so that the CCD visual positioning device is used to identify and locate the printing area on the surface of the battery cell to facilitate subsequent precise printing.

[0035] In step S3, for the printing area on the surface of the battery cell identified and located by the CCD visual positioning device, the control system controls the printing station of the printing device to print the printing area, and then moves it to the curing station for curing to print an insulating layer on the surface of the battery cell to obtain a printed battery cell.

[0036] In step S4, the inspection process includes appearance inspection, insulation layer thickness inspection, shear performance and insulation withstand voltage performance inspection, such as detecting whether there are white spots, pitting, white spots, orange peel and other appearance defects on the surface of the battery cell, detecting whether the thickness of the insulation layer meets the standard, detecting whether the shear performance and insulation withstand voltage performance of the insulation layer meet the standard, etc., so as to determine whether the printed battery cell meets the standard.

[0037] Thus, in the pre-treatment process, the roughening treatment of the cell surface adopts a flat-top laser. The center energy of the flat-top laser is the same as the edge energy, which can evenly roughen the cell surface and avoid damaging the cell surface, thereby improving the efficiency and roughness of the cell surface roughening treatment, and ensuring the consistency of the roughness, which is beneficial to improving the adhesion of the cell surface. The cell surface roughening treatment and dust removal treatment are carried out simultaneously, which can remove the aluminum powder generated by the roughening treatment in time, and then cooperate with the subsequent plasma cleaning treatment to ensure that the aluminum powder on the cell surface is completely removed, so that after the printing area on the cell surface is printed and cured to obtain the insulating layer, the appearance defects such as white spots and pitting on the cell surface can be avoided, and the insulation withstand voltage performance and shear strength of the insulating layer can be improved.

[0038] On this basis, in step S1, the roughening treatment adopts the flat-top laser flying process, the laser galvanometer of the laser for providing the flat-top laser is fixed, the flat-top laser is emitted in a linear form with a specific direction and specific energy, and the battery cell moves along a preset path so that each surface thereof is roughened in turn, and avoids the specific area of ​​the battery cell, and the specific area includes at least one of the pole, the QR code, the explosion-proof valve and the blank area surrounding the three. That is, the laser galvanometer is controlled to be fixed, and the flat-top laser is controlled to be emitted in a linear form of a line, and the flat-top laser is used to roughen each surface of the battery cell by moving the battery cell. Taking the square battery cell as an example, each surface includes two relatively large surfaces, two relatively side surfaces, and the top and bottom surfaces of the battery cell. All six surfaces need to be roughened, and on the basis of the laser galvanometer being fixed and the flat-top laser being emitted in a linear form with a specific direction and specific energy, the battery cell is controlled to move so as to roughen the six surfaces of the battery cell in turn.

[0039] In the prior art, laser roughening generally uses a contour-scanning method to keep the battery cell stationary and use the laser to move to roughen the surface of the battery cell, so that the range of aluminum powder generated on the surface of the battery cell is large, the range of dust removal during roughening is large, and the dust removal device needs to cover a large range, resulting in a low dust removal wind speed, poor dust removal effect, and not conducive to the timely removal of aluminum powder, thereby affecting the appearance of the printed insulation layer and the insulation withstand voltage performance, shear strength, etc. In the flat-top laser flight process of the present application, the flat-top laser light output is fixed, and the movement of the battery cell is controlled to achieve roughening. Since the flat-top laser is linear, the range of aluminum powder generated on the surface of the battery cell during roughening is small, which greatly reduces the range of dust removal during roughening, and can quickly remove the aluminum powder generated by roughening, thereby avoiding the appearance defects such as white spots and pitting on the surface of the battery cell after the insulation layer is printed, and improving the insulation withstand voltage performance and shear strength of the insulation layer. In addition, it is beneficial to improve the efficiency of the roughening process and simplify the roughening process path.

[0040] It should be noted that during the texturing process, it is necessary to control the light output parameters of the flat-top laser and the movement parameters of the battery cell, and coordinate the two to achieve efficient texturing of the battery cell surface. No specific limitation is made on the parameters here. The settings of each parameter vary according to different actual working conditions, and can be set according to the texturing requirements.

[0041] Avoiding air gaps can avoid damage to specific areas, thereby ensuring the normal performance of the battery. Visual positioning equipment is used to identify specific areas of the battery and transmit them to the control system, so that the control system can control the roughening process to avoid specific areas. The roughening process station is equipped with a CCD visual positioning station, and in conjunction with the control program, it can identify specific areas of the battery in a timely manner, thereby avoiding the specific areas from being roughened.

[0042] In step S1, the dust removal treatment adopts a negative pressure dust extraction method, and the negative pressure dust suction nozzle of the dust removal equipment is aimed at the roughened surface of the battery cell, and the negative pressure dust suction nozzle is flat. In the prior art, while the laser roughening treatment is being carried out, the aluminum powder generated by the laser roughening on the surface of the battery cell is removed by a combination of positive pressure air knife blowing and negative pressure exhaust. However, the positive pressure air knife blowing is difficult to control, and it is easy to blow the aluminum powder to the surroundings and exceed the range of negative pressure exhaust, causing secondary pollution of the aluminum powder, resulting in the aluminum powder cannot be completely removed, so that white spots, pitting and other appearance defects appear on the surface of the battery cell after printing, and it will affect the insulation withstand voltage performance and shear strength of the printed insulation layer. The present application uses negative pressure dust extraction to remove dust from the surface of the battery cell while performing the flat-top laser roughening treatment, which can remove the aluminum powder generated by roughening in time. In addition, since the flat-top laser is linear, the range of aluminum powder generated on the surface of the battery cell during the texturing process is small, which greatly reduces the range of simultaneous dust removal during the texturing process. The negative pressure suction nozzle can be set to a flat structure, which is beneficial to increase the wind speed at the suction nozzle, so that the aluminum powder generated by the texturing process can be removed in time without the influence of positive pressure air knife blowing, which greatly improves the efficiency of aluminum powder removal.

[0043] In step S1, a plasma gas flow is used to blow toward the roughened surface of the battery cell to perform a plasma cleaning treatment on the battery cell. The plasma cleaning treatment is set to avoid a small amount of aluminum powder remaining on the surface of the battery cell after the dust removal treatment in step S1, and the plasma surface treatment can also use the plasma gas flow to remove static electricity and gasified residual pollutants on the surface of the battery cell, thereby enhancing the activation energy of the battery cell surface and providing better battery cell surface conditions for the leveling and adhesion of the printed insulation layer.

[0044] In addition, in step S1, before the plasma cleaning process is performed, the battery cell with a roughened surface is subjected to at least one negative pressure dust removal process, and the dust removal nozzle of the negative pressure dust removal equipment is aligned with the roughened surface of the battery cell, and the dust removal nozzle is a flared structure. In general, the simultaneous dust removal of the roughening process can achieve the removal of all or most of the aluminum powder, and combined with the plasma cleaning process, the surface of the battery cell can be free of pollutants. Based on this, in order to prevent a large amount of aluminum powder or special working conditions, at least one negative pressure dust removal processing station is set before the plasma cleaning processing station to ensure that the aluminum powder is completely removed by negative pressure exhaust. In practical applications, the number of negative pressure dust removal processing stations can be set according to the removal effect, and there is no uniform regulation on the number, with the purpose of completely removing the aluminum powder. In addition, the negative pressure dust removal process is to remove dust from the entire surface of the battery cell that has been moved into place and has been roughened, with a large range, and the amount of aluminum powder is small and scattered, so the dust removal nozzle is set to a flared structure, which can achieve a large range of aluminum powder extraction to ensure the complete removal of aluminum powder at each position.

[0045] The above are the main operating steps of the pre-treatment process. It is worth noting that, taking the square battery cell as an example, the six surfaces of the battery cell are all pre-treated before being moved to the subsequent workstation for subsequent steps.

[0046] For step S3, the printing area is sprayed and cured multiple times by combining top spraying, side spraying and edge spraying, so as to print an insulating layer on the surface of the battery cell to obtain a printed battery cell. When the surface of the battery cell is sprayed, the top spraying method is generally adopted, that is, the upper surface of the battery cell moved to the spray printing station is sprayed, and then moved to the curing station for curing, and then the battery cell is turned over for the next round of spray printing and curing, and the cycle is repeated until all surfaces of the battery cell are sprayed and cured, which has the defects of many flipping times, complicated operation and low efficiency. The present application adopts a combination of top spraying and side spraying, that is, the upper surface and side of the battery cell are sprayed at the same time, and then moved to the curing station for curing, so that the number of flipping of the battery cell can be reduced and the printing efficiency can be improved.

[0047] The printing on each surface of the battery cell is carried out in small amounts and multiple times. It not only uses multiple nozzles for partitioned printing, but also cooperates with edge spraying to ensure that each surface and edge of the battery cell can be evenly printed and cured, so that the thickness error range of the insulation layer is within ±10μm, and the occurrence of whitening problems is avoided, so that the insulation layer can evenly cover the entire surface of the battery cell.

[0048] In addition, each printing and curing process includes printing, pre-curing and final curing in sequence, and the light intensity of final curing is greater than that of pre-curing. That is, after each printing on the surface of the battery cell is completed, it needs to be moved to the pre-curing station for pre-curing, and then moved to the final curing station with stronger light intensity for final curing, so as to ensure the adhesion and stability of the insulation layer, which is conducive to improving the insulation withstand voltage performance and shear strength.

[0049] In addition to the above main steps, a rolling step is also included before step S1, in which a rolling device is used to roll the edges of the battery cell, the welding slag and burrs on the surface of the battery cell to make the surface of the battery cell smooth. If the welding edges on the surface of the battery cell, the welding slag and burrs in the R-angle area are not processed, they are very easy to be broken down during the insulation withstand voltage test of the printed insulation layer, thereby greatly affecting the insulation withstand voltage performance. Taking the thickness of the insulation layer of 100um as an example, when the protrusion of the burr tip is greater than 0.05mm, it is very easy for the insulation withstand voltage test to be broken down. Therefore, the present application uses a rolling device in conjunction with a positioning device to roll the welding edges on the surface of the battery cell, the welding slag and burrs in the R-angle area, so that the protrusions of the welding edges, welding slag, burrs, etc. are smooth to ensure the insulation withstand voltage performance of the insulation layer.

[0050] Among them, the rolling equipment can be a common device in the prior art including structures such as a motor, a screw rod, a cylinder, a guide rail, a slider, etc., and the positioning equipment can be a common device in the prior art including structures such as an adjustment module, a cylinder, a base, etc. The cooperation between the rolling equipment and the positioning equipment can ensure the accuracy of rolling.

[0051] A screening step is also included between the rolling step and step S1, in which the surface of the battery cell is identified by a visual inspection device to screen out defective products. After the rolling step, the battery cell can be transported to a visual inspection station, and the surface of the battery cell can be inspected by a CCD visual inspection device to screen out defective products, and the good products can be transported to a pre-processing station for pre-processing to improve the yield of the printing of the insulating layer on the surface of the battery cell.

[0052] In this way, the method for printing the insulating layer on the surface of the battery cell of the present application firstly performs a roller pressing process on the protrusions on the surface of the battery cell and performs a good product screening to ensure that the battery cell to be printed is a good product. Then, a flat-top laser flying roughening process is adopted in combination with synchronous negative pressure dust extraction + at least one negative pressure dust removal process + plasma cleaning process, which can accurately avoid the empty battery cell pole surface, and the process is simple, pollution-free, and low in energy consumption; the surface of the battery cell can be evenly roughened and the oil, electrolyte, oxide layer and other pollutants on the surface of the battery cell can be completely removed, and the amount of aluminum powder produced is small and damage to the surface of the battery cell is avoided, and no tiny burrs are generated on the surface of the battery cell, thereby improving the efficiency and roughness of the roughening process on the surface of the battery cell, and the consistency of the roughness can be ensured, which is conducive to improving the adhesion of the surface of the battery cell; static electricity and gasified residual pollutants on the surface of the battery cell can be removed, thereby enhancing the activation energy of the surface of the battery cell, and providing better surface conditions for the leveling and adhesion of the printed insulating layer. Then, a visual positioning device is used to identify and locate the printing area on the surface of the battery cell to ensure the accuracy of the printing. Then, by using the combination of top spraying, side spraying and edge supplementation, multiple nozzles are used for quantitative and small-scale multiple printing, pre-curing and final curing, so that the insulation layer can be evenly covered on the entire surface of the battery cell, and the adhesion and stability of the insulation layer are guaranteed. The utilization rate of the printing ink is as high as 98%, which greatly reduces the waste of materials. Finally, with the combination of appearance inspection, insulation layer thickness inspection, shear performance and insulation withstand voltage performance inspection, the insulation layer thickness error range of the good quality printed battery cell can be guaranteed to be within ±10μm, and the appearance defects such as white spots and pitting on the surface of the battery cell after the insulation layer is printed can be avoided, and the insulation withstand voltage performance and shear strength of the insulation layer can be improved.

[0053] The technical means disclosed in the present application are not limited to the technical means disclosed in the above-mentioned implementation methods, but also include technical solutions composed of any combination of the above technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also regarded as the protection scope of this application.

Claims

1. A method for printing an insulating layer on the surface of a battery cell, characterized in that: The following steps are involved: S1. Pre-treatment: using a flat-top laser to roughen the surface of the battery cell and simultaneously perform dust removal, and then performing plasma cleaning on the battery cell with the roughened surface; S2. Confirm the printing area: use a visual positioning device to identify and locate the printing area on the surface of the battery cell; S3, printing: performing printing and curing on the printing area to print an insulating layer on the surface of the battery cell to obtain a printed battery cell; S4, testing: testing the printed battery cell to determine whether it meets the standards.

2. The method for printing the insulating layer on the surface of a battery cell according to claim 1, characterized in that: In the step S1, the texturing treatment adopts a flat-top laser flying process, the laser galvanometer of the laser for providing the flat-top laser is fixed, the flat-top laser is emitted linearly in a specific direction and with specific energy, the battery cell moves along a preset path so that its surfaces are texturing treated in turn, and a specific area of ​​the battery cell is avoided, the specific area includes at least one of the pole of the battery cell, the QR code, the explosion-proof valve and the blank area surrounding the three.

3. The method for printing the insulating layer on the surface of a battery cell according to claim 2, characterized in that: A visual positioning device is used to identify a specific area of ​​the battery cell and transmit the identification to a control system, so that the control system controls the texturing process to avoid the specific area.

4. The method for printing the insulating layer on the surface of a battery cell according to claim 2, characterized in that: In the step S1, the dust removal process is carried out by means of negative pressure dust extraction, the negative pressure suction nozzle of the dust removal equipment is aimed at the roughened surface of the battery cell, and the negative pressure suction nozzle is flat.

5. The method for printing the insulating layer on the surface of a battery cell according to claim 1, characterized in that: In the step S1, a plasma gas flow is blown toward the roughened surface of the battery cell to perform a plasma cleaning treatment on the battery cell.

6. The method for printing the insulating layer on the surface of a battery cell according to claim 1, characterized in that: In the step S3, the printing area is printed and cured multiple times by combining top spraying, side spraying and edge spraying, so as to print an insulating layer on the surface of the battery cell to obtain a printed battery cell.

7. The method for printing the insulating layer on the surface of a battery cell according to claim 6, characterized in that: Each printing and curing process includes printing, pre-curing and final curing performed in sequence, and the light intensity of the final curing is greater than the light intensity of the pre-curing.

8. The method for printing the insulating layer on the surface of a battery cell according to claim 1, characterized in that: In step S4, the inspection process includes appearance inspection, insulation layer thickness inspection, shear performance and insulation withstand voltage performance inspection.

9. The method for printing the insulating layer on the surface of a battery cell according to any one of claims 1 to 8, characterized in that: In the step S1, before the plasma cleaning treatment is performed, the battery cell with the roughened surface is subjected to at least one negative pressure dust removal treatment, the dust removal nozzle of the negative pressure dust removal equipment is aligned with the roughened surface of the battery cell, and the dust removal nozzle is a flared structure.

10. The method for printing the insulating layer on the surface of a battery cell according to any one of claims 1 to 8, characterized in that: Before step S1, a rolling step is also included, in which a rolling device is used to roll the edges of the battery cell, welding slag and burrs on the surface of the battery cell to make the surface of the battery cell smooth.

11. The method for printing the insulating layer on the surface of a battery cell according to claim 10, characterized in that: A screening step is also included between the rolling step and the step S1, in which a visual inspection device is used to identify the surface of the battery cell to screen out defective products.