Battery upper cover jet printing protection process

Abstract

The invention discloses a battery upper cover jet printing protection process which comprises the following steps: 1) pretreatment of a battery upper cover: before the jet printing protection process is carried out, cleaning the surface of the battery upper cover to remove surface impurities; 2) setting jet printing parameters: setting the jet printing parameters by controlling jet printing equipment of a nozzle; 3) spray printing of an insulating coating: uniformly and directly spraying an insulating coating material on an area to be subjected to spray printing on the pole surface of the battery by using a spray head; and 4) curing treatment: after jet printing is completed, curing treatment is carried out on the battery upper cover with the insulating coating. Through a mode of directly spraying and printing by the spray head, a non-jet-printing area can be avoided, and an insulating coating is uniformly and directly sprayed on a to-be-jet-printed area of a battery polar column surface; therefore, the problems of unstable adhesion, reduced energy density, non-uniform thickness of an insulating layer, incapability of effectively treating weld seam welding slag defects and the like in an existing battery upper cover protection process are solved, the stability of the battery is improved, the service life of the battery is prolonged, and the product yield is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of battery manufacturing, and particularly to a printing protection process for a battery upper cover. Background Art

[0002] During the battery manufacturing process, the protection of the battery upper cover is crucial. The traditional battery blue film coating process uses the method of attaching a top cover patch to the top cover to protect the battery upper cover. However, this method has many drawbacks. For example, the top cover patch relies on the adhesive layer for pasting. If the adhesive layer is too thin, the pasting strength will be low and it cannot be effectively bonded. If the adhesive layer is too thick, it will waste the adhesive and also reduce the battery energy density.

[0003] In addition, although the process of spraying insulating powder on the battery surface is also used for protecting the battery upper cover, during spraying, the thickness of the insulating powder is affected by static force and it is easy to have uneven thickness. Especially at the battery corners, it is difficult to meet the process requirements, which affects the battery insulation performance and lifespan. Moreover, for defects such as weld seams and welding slag left during the welding of the battery upper cover, this process cannot effectively solve them, and breakdown phenomena are likely to occur, resulting in a low product yield.

[0004] With the development of the inkjet printing process, a printing process for a lithium battery upper cover protection layer was subsequently developed. The Chinese invention patent "A Printing Process for a Lithium Battery Upper Cover Protection Layer" with the application number 202210580717.2 divides the printing area into a first printing area and a second printing area, and cooperates with a specially designed ink-splashing baffle with a hollow printing window to achieve printing on the positions that need to be inkjet printed while avoiding ink splashing onto non-printing parts such as the positive and negative electrodes, liquid injection holes, and two-dimensional code areas of the lithium battery upper cover. However, this process relies on the ink-splashing baffle for shielding printing, with low efficiency, and due to the relatively long printing distance, problems such as uneven spraying of the protection layer are likely to occur. Summary of the Invention

[0005] In view of the above deficiencies, the purpose of the present invention is to provide a printing protection process for a battery upper cover. By directly spraying and printing with a nozzle, it can avoid non-printing areas and evenly spray the insulating coating directly on the printing area of the battery pole column surface, thereby solving problems existing in the existing battery upper cover protection processes such as poor adhesion, reduced energy density, uneven thickness of the insulating layer, and inability to effectively handle weld seam and welding slag defects, and improving the stability, service life, and product yield of the battery.

[0006] The technical solution adopted by the present invention is as follows: The printing protection process for a battery upper cover, and the specific steps are as follows:

[0007] Pre-treatment of the battery upper cover: Before the spray printing protection process, clean the surface of the battery upper cover to remove impurities such as dust and oil on the surface, ensuring that the surface is clean and dry. Ultrasonic cleaning, chemical cleaning and other methods can be used for cleaning. After cleaning, dry the battery upper cover to ensure that there is no residual moisture on the surface, providing conditions for the good adhesion of the subsequent insulating coating.

[0008] Set spray printing parameters: According to the specifications, models of the batteries and the required insulating performance, set the spray printing parameters through the spray printing equipment that controls the nozzles. These parameters include the moving speed of the nozzles, the size of the spray holes, the size of the spray printing pattern, the thickness of the insulating coating and the number of spray printing times, etc. For example, for batteries of different sizes, adjust the size of the spray printing pattern to completely cover the battery terminal surface; according to the usage environment and insulating requirements of the batteries, set the appropriate coating thickness.

[0009] Spray printing of the insulating coating: Use the nozzles to evenly and directly spray the insulating coating material on the area to be spray printed on the battery terminal surface, avoiding the non-spray printing area where the battery terminals are located. The nozzles are controlled by a computer program and spray print according to the preset spray printing pattern and parameters. Under the spraying force of the nozzles, the insulating coating material is ejected at a relatively large initial speed of 6.5 - 7 m / s, reducing the influence of external factors such as the wind field, so that the insulating coating adheres more evenly to the surface of the battery upper cover. During the spray printing process, ensure that the insulating coating completely covers other surface positions except the non-spray printing area where the battery terminals are located and possible defect parts such as welds and welding slag. Generally speaking, only spray print the positions that need to be spray printed, and avoid the positions that do not need to be spray printed; that is to say, other surface positions, welds, welding slag and other defect parts outside the non-spray printing area can be collectively referred to as the "positions to be spray printed".

[0010] Curing treatment: After spray printing, conduct curing treatment on the battery upper cover with the insulating coating. The curing method can be selected according to the characteristics of the insulating coating material, such as heat curing, light curing, etc. Heat curing can be carried out in an oven, setting appropriate temperature and time to fully cure the insulating coating; light curing uses light with a specific wavelength to irradiate the insulating coating to make it cure quickly. The cured insulating coating is tightly combined with the battery upper cover to form a stable protection structure.

[0011] Quality inspection: Conduct quality inspection on the battery upper cover that has completed the spray printing protection process. The inspection contents include whether the thickness of the insulating coating is uniform, whether it completely covers the battery terminal surface and defect parts, and whether the insulating performance meets the requirements, etc. A coating thickness gauge can be used to detect the coating thickness, and an insulation resistance tester can be used to test the insulating performance. For unqualified products detected, rework or scrapping treatment is carried out.

[0012] Blue film coating (optional step): According to actual requirements, after spraying the insulating coating and passing the inspection, the battery is coated with a blue film. The blue film coating further enhances the protection effect of the battery upper cover and improves the overall protection performance of the battery.

[0013] For the above-mentioned printing protection process of the battery upper cover, it can be that the printing protection process of the battery upper cover is carried out after the battery upper cover is assembled to the battery case; or it can be that the battery upper cover is first subjected to the printing protection process of the battery upper cover and then assembled to the battery case.

[0014] The present invention has the following advantages:

[0015] High process efficiency: Without relying on a flying ink baffle, by directly spraying and printing through a nozzle, it is possible to avoid non-printing areas and directly spray the insulating coating evenly on the area to be printed on the battery terminal surface (for example, other surface positions of the battery upper cover except the positions where the battery terminals are located), forming a uniform insulating protection coating.

[0016] Strong adhesion: The insulating coating itself has good adhesion, can better fit the battery body, and is not easy to fall off compared with the traditional top cover patch process, effectively ensuring the protection effect of the battery upper cover.

[0017] Excellent protection performance: When the battery is subjected to external extrusion, bumping, scraping and other damages, the insulating coating can play an effective role in isolation and protection, avoiding damage to the core body and extending the service life of the battery.

[0018] Strong adaptability: By setting the size of the printed pattern, it is possible to conveniently and quickly meet the requirements of different specifications of batteries, without significantly adjusting the equipment structure, saving equipment costs and improving production efficiency.

[0019] Uniform insulating layer: The insulating coating sprayed from the nozzle holes of the nozzle is printed more evenly on the battery body, and the spraying force makes the initial velocity of the coating larger, and it is not easily affected by external factors such as the wind field, ensuring the quality stability of the insulating coating.

[0020] Solving the problem of weld slag: For defects such as welds and weld slag on the battery upper cover, by setting the number of printing times, the thickness of the insulating coating at these parts can reach the requirements to meet the battery performance, effectively improving the yield of the product.

[0021] The following further illustrates the present invention in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0022] Figure 1 It is a structural schematic diagram of the battery;

[0023] Figure 2 It is a structural schematic diagram of the nozzle;

[0024] In the figure: nozzle 1; battery upper cover 2; battery upper cover 3; battery terminal 4; battery terminal surface 5. Specific implementation mode

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] It should be noted that if there are directional indications (such as up, down, left, right, front, back, top, bottom, inner, outer, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial...) involved in the embodiments of the present invention, then the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0027] In addition, if there is a description involving "first" or "second" in the embodiments of the present invention, then the description of "first" or "second" is only for descriptive purposes and cannot be understood as indicating or implying its relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0028] See Figures 1 to 2 , the battery upper cover printing protection process provided by this embodiment is specifically as follows:

[0029] 1) Pretreatment of the battery upper cover 2: Before the printing protection process, clean the surface of the battery upper cover 3 of the battery body 2 to remove impurities such as dust and oil stains on the surface, and ensure that the surface is clean and dry. Ultrasonic cleaning, chemical cleaning and other methods can be used for cleaning. After cleaning, dry the battery upper cover to ensure that there is no moisture residue on the surface, providing conditions for the good adhesion of the subsequent insulating coating.

[0030] 3) Set the printing parameters: According to the specifications, models of the batteries and the required insulation performance, set the printing parameters through the printing equipment that controls the nozzle 1. These parameters include the moving speed of the nozzle 1, the size of the nozzle holes, the size of the printed pattern, the thickness of the insulation coating, and the number of printing passes, etc. For example, for batteries of different sizes, adjust the size of the printed pattern to completely cover the battery terminal surface; according to the usage environment and insulation requirements of the battery, set an appropriate coating thickness.

[0031] 4) Insulation coating printing: Use the nozzle 1 to evenly and directly spray the insulation coating material on the area to be printed on the battery terminal surface 5, and avoid the non-printing area where the battery terminal 4 is located. The nozzle is controlled by a computer program and prints according to the preset printed pattern and parameters. Under the spraying force of the nozzle, the insulation coating material is ejected at a set relatively large initial velocity (6.5 - 7 m / s), reducing the influence of external factors such as the wind field, so that the insulation coating adheres more evenly to the surface of the battery upper cover. During the printing process, ensure that the insulation coating completely covers other surface positions except the non-printing area where the battery terminal is located and possible defect sites such as welds and welding slag. Generally speaking, only print the positions that need to be printed, and avoid the positions that do not need to be printed; that is to say, other surface positions, welds, welding slag and other defect parts outside the non-printing area can be collectively referred to as "positions to be printed".

[0032] 5) Curing treatment: After printing is completed, perform curing treatment on the battery upper cover 3 with the insulation coating. The curing method can be selected according to the characteristics of the insulation coating material, such as heat curing, light curing, etc. Heat curing can be carried out in an oven, setting appropriate temperature and time to fully cure the insulation coating; light curing uses light of a specific wavelength to irradiate the insulation coating to make it cure quickly. The cured insulation coating is tightly combined with the battery upper cover to form a stable protection structure.

[0033] 6) Quality inspection: Perform quality inspection on the battery upper cover that has completed the printing protection process. The inspection contents include whether the thickness of the insulation coating is uniform, whether it completely covers the battery terminal surface and defect sites, and whether the insulation performance meets the requirements, etc. A coating thickness gauge can be used to detect the coating thickness, and an insulation resistance tester can be used to test the insulation performance. For unqualified products detected, rework or scrapping treatment is carried out.

[0034] For the above-mentioned printing protection process of the battery upper cover, in this embodiment, after the battery upper cover is assembled to the battery housing, the printing protection process of the battery upper cover is carried out.

[0035] Another embodiment is that the battery upper cover first undergoes the printing protection process of the battery upper cover and then is assembled to the battery housing.

[0036] The above embodiments are only partial implementation manners of the present invention. In actual applications, the process parameters can be adjusted and optimized according to the characteristics and requirements of different batteries.

[0037] In summary, the battery cover spray printing protection process of the present invention can effectively solve the problems existing in the existing battery cover protection process, has significant economic benefits and practical value, and is worthy of wide promotion and application in the battery manufacturing industry.

[0038] The present invention is not limited to the above embodiments. Other battery cover spray printing protection processes obtained by adopting the same or similar technical features as those of the above embodiments of the present invention are within the protection scope of the present invention.

Claims

1. A battery cover printing protection process, characterized in that: The steps include: 1) Pretreatment of the battery cover: Before the printing protection process, clean the surface of the battery cover to remove surface impurities and ensure that the surface is clean and dry; 2) Setting printing parameters: according to the specifications, models and required insulation performance of the battery, the printing parameters are set by controlling the printing device of the nozzle; 3) Insulation coating printing: Use a nozzle to evenly spray the insulation coating material directly on the area to be printed on the battery pole surface, and avoid the non-printing area where the battery pole is located; 4) Curing treatment: After the printing is completed, the battery cover with the insulating coating is cured.

2. The battery cover printing protection process according to claim 1, characterized in that: The following steps are also included: 5) Quality inspection: Perform quality inspection on the battery cover that has completed the printing protection process.

3. The battery cover printing protection process according to claim 1, characterized in that: After the battery cover is assembled to the battery shell, the battery cover is subjected to a spray printing protection process; alternatively, the battery cover is subjected to a spray printing protection process first and then assembled to the battery shell.

4. The battery cover printing protection process according to claim 1, characterized in that: In step 1), the cleaning process adopts ultrasonic cleaning or chemical cleaning.

5. The battery cover printing protection process according to claim 1, characterized in that: In step 2), the printing parameters include the moving speed of the nozzle, the size of the nozzle hole, the size of the printed pattern, the thickness of the insulating coating or the number of printing times.

6. The battery cover printing protection process according to claim 1, characterized in that: In step 3), the nozzle is controlled by a computer program and prints according to preset printing patterns and parameters; the insulating coating material is sprayed out at a set initial velocity of 6.5-7m / s under the spray force of the nozzle, reducing the influence of external factors, so that the insulating coating is evenly attached to the surface of the battery cover; during the printing process, ensure that the insulating coating completely covers other surface positions except the non-printing area where the battery pole is located, as well as the existing welds and welding slag defects.

7. The battery cover printing protection process according to claim 1, characterized in that: In step 4), the curing method is selected from thermal curing or photocuring according to the characteristics of the insulating coating material.

Images