Spray printing method and system for insulating coating on surface of battery cell

Abstract

The invention discloses a jet printing method and system for an insulating coating on the surface of a battery cell. The method is used for controlling a spray head to sequentially form an insulating coating on each surface of a battery cell; wherein the first surface is a polar column surface; the sprayers comprise top sprayers and side sprayers; the method comprises the following steps: placing the front surface of the third surface of the battery cell upwards; performing at least one time of ink jet printing on the first surface and the second surface in sequence by using a side nozzle; carrying out primary ink jet printing on the third surface by adopting a top surface spray head; rotating the battery cell to enable the front surface of the sixth surface to be placed upwards; sequentially carrying out at least one time of ink jet printing on the fourth surface and the fifth surface by adopting a side spray head; carrying out primary ink jet printing on the sixth surface by adopting a top surface spray head so as to complete jet printing of an insulating coating on each surface of the battery cell; wherein the second surface is opposite to the first surface. According to the technical scheme provided by the embodiment of the invention, the six-surface jet printing of the square battery cell can be realized by adopting the UV jet printing process under the condition that the polar column surface of the battery cell is not inversely buckled.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and in particular to a method and system for spraying an insulating coating on the surface of a battery cell. Background Art

[0002] As the lithium battery industry's CTP / CTB trend places increasingly higher demands on the surface structural strength of battery cells, insulating coatings have become the industry's development trend, replacing the original blue film wrapping method.

[0003] At present, the main ways to replace the original blue film with insulating coating include insulating powder spraying, UV spray painting, and UV printing. Among them, insulating powder spraying and UV spray painting both have certain technical disadvantages, while UV printing can effectively solve the technical disadvantages of insulating powder spraying and UV spray painting in principle, and the coating thickness formed is uniform, the ink utilization rate is high, and there is no need to stick an insulating cover plate, which has the feasibility of achieving full automation. However, the existing UV printing process is generally implemented by top spraying. In this way, when printing on the six sides of a square battery cell, the battery cell needs to be frequently flipped, and the pole surface of the battery cell needs to be inverted to achieve this, and the pole surface of the battery cell is often not allowed to be inverted. Therefore, the existing UV printing process implemented by top spraying cannot achieve six-sided printing of square batteries. Summary of the Invention

[0004] The present invention provides a method and system for printing an insulating coating on the surface of a battery cell, so as to solve the problem that the UV printing process cannot realize six-sided printing of a square battery cell when the battery cell pole surface is not inverted.

[0005] According to one aspect of the present invention, a method for printing an insulating coating on the surface of a battery cell is provided, which is used to control a nozzle to sequentially form an insulating coating on each surface of the battery cell; wherein the battery cell includes a first surface, a second surface, a third surface, a fourth surface, a fifth surface, and a sixth surface, the first surface being a pole surface; the nozzle includes a top nozzle and a side nozzle;

[0006] The method for printing the insulating coating on the surface of the battery cell comprises:

[0007] Place the third surface of the battery cell facing upward;

[0008] Using the side nozzle to sequentially print ink on the first surface and the second surface at least once, and then curing;

[0009] Using the top surface nozzle to print ink on the third surface once, and then curing the ink;

[0010] Rotating the battery cell so that the sixth surface faces upward;

[0011] Using the side nozzle to sequentially print ink on the fourth surface and the fifth surface at least once, and then curing the ink;

[0012] Using the top surface nozzle to print ink on the sixth surface once, and then curing the ink to complete the printing of the insulating coating on each surface of the battery cell;

[0013] The second surface is opposite to the first surface, the third surface is opposite to the sixth surface, and the fourth surface is opposite to the fifth surface.

[0014] Optionally, the step of sequentially printing ink on the first surface and the second surface at least once using the side nozzle and curing the ink comprises:

[0015] Using the side nozzle to print ink on the first surface at least once, and then curing the ink;

[0016] Using the side nozzle to print ink on the second surface at least once, and then curing the ink;

[0017] The step of using the side nozzle to sequentially print ink on the fourth surface and the fifth surface at least once and then curing the ink comprises:

[0018] Using the side nozzle to print ink on the fourth surface at least once, and then curing the ink;

[0019] The side nozzle is used to print ink on the fifth surface at least once and then solidify the ink.

[0020] Optionally, before printing ink on the first surface at least once using the side nozzle, the method further includes:

[0021] Using the top surface nozzle to spray ink on the first edge of the third surface and perform pre-curing;

[0022] Before the side nozzle is used to print ink on the fourth surface at least once, the method further includes:

[0023] Using the top surface nozzle to spray ink on the first edge of the sixth surface and perform pre-curing;

[0024] Using the side nozzle to spray ink on the second edge of the fourth surface and perform pre-curing;

[0025] Before the side nozzle is used to print ink on the fifth surface at least once, the method further includes:

[0026] Using the side nozzle to spray ink on the second edge of the fifth surface and perform pre-curing;

[0027] The length of the second edge is smaller than the length of the first edge.

[0028] Optionally, the step of printing ink on the first surface at least once using the side nozzle and curing the ink comprises:

[0029] Using the side nozzle to print ink and pre-curing the ink on the first surface, and repeating the process twice;

[0030] Using the side nozzle to print ink on the first surface and perform final curing;

[0031] or,

[0032] The step of printing ink on the second surface at least once using the side nozzle and curing the ink comprises:

[0033] Using the side nozzle to print ink and pre-curing the ink on the second surface, and repeating the process twice;

[0034] Using the side nozzle to print ink on the second surface and perform final curing;

[0035] or,

[0036] The step of printing ink on the fourth surface at least once using the side nozzle and curing the ink comprises:

[0037] Using the side nozzle to print ink and pre-curing the ink on the fourth surface, and repeating the process twice;

[0038] Using the side nozzle to print ink and perform final curing on the fourth surface;

[0039] or,

[0040] The step of printing ink on the fifth surface at least once using the side nozzle and curing the ink comprises:

[0041] Using the side nozzle to print ink and pre-curing the ink on the fifth surface, and repeating the process twice;

[0042] The side nozzle is used to print ink on the fifth surface and perform final curing.

[0043] Optionally, the method of printing ink on the surface of the battery cell and curing the ink comprises:

[0044] Obtaining a position coordinate matrix of an area to be printed on the surface of the battery cell;

[0045] Rasterizing the image of the area to be printed according to the position coordinate dot matrix, and generating nozzle position information and ink volume information; wherein the nozzle position information and the ink volume information are both mapped to the position coordinate dot matrix;

[0046] Controlling the ink path system to deliver ink to the nozzle according to the nozzle position information and the ink amount information;

[0047] The nozzle is controlled to print ink onto the surface of the battery cell and solidify the ink, and at least one printing and solidification operation is performed to complete the printing of the insulating coating on the surface of the battery cell.

[0048] Optionally, obtaining a position coordinate matrix of an area to be printed on the surface of the battery cell includes:

[0049] Calibrate the position coordinate system of the printing system and the position coordinate system of the visual positioning system, and generate a position calibration file;

[0050] collecting an image to be processed of the surface of the battery cell, performing image processing on the image to be processed and integrating the image into the position calibration file;

[0051] The position calibration file is called to perform image processing on the image to be processed, to generate a rendering of the area to be printed, and to obtain the position coordinate dot matrix of the area to be printed.

[0052] Optionally, the area to be printed includes areas other than the explosion-proof valve, the pole and the QR code area on the first surface.

[0053] Optionally, the nozzle includes a plurality of nozzle modules, and each nozzle module includes a plurality of nozzles;

[0054] The step of controlling the nozzle to print ink onto the surface of the battery cell and solidify the ink, and performing at least one printing and solidification operation, includes:

[0055] Controlling a first preset number of the nozzles to perform multiple printing and curing operations on the surface of the battery cell;

[0056] Alternatively, controlling a second preset number of nozzles to perform a printing and curing operation on the surface of the battery cell;

[0057] The sum of the first preset number of the nozzles used in multiple printing and curing operations is equal to the second preset number of the nozzles.

[0058] Optionally, the ink path system is controlled to deliver ink to the nozzle, comprising:

[0059] regulating a preset temperature in an ink tube of the ink system so as to maintain the preset temperature at a constant temperature;

[0060] The ink tube of the ink path system is controlled to maintain a high-precision negative pressure state, so that the ink path system delivers ink to the nozzle according to the ink amount information.

[0061] According to another aspect of the present invention, a system for printing an insulating coating on the surface of a battery cell is provided, for executing the method for printing an insulating coating on the surface of a battery cell as described in any embodiment of the first aspect.

[0062] The method for printing an insulating coating on the surface of a battery cell provided by an embodiment of the present invention is used to control the nozzle to sequentially form an insulating coating on each surface of the battery cell. The battery cell includes a first surface and a second surface arranged opposite to each other, a third surface and a sixth surface arranged opposite to each other, and a fourth surface and a fifth surface arranged opposite to each other. By placing the third surface of the battery cell with the front side facing upward, the side nozzle is used to sequentially print and cure the ink on the first surface and the second surface at least once, and the top nozzle is used to print and cure the ink once on the third surface. Thereafter, the battery cell is rotated and the sixth surface is placed with the front side facing upward. The side nozzle is used to sequentially print and cure the ink on the fourth surface and the fifth surface at least once, and the top nozzle is used to print and cure the ink on the sixth surface, thereby completing the printing of all six surfaces of the square battery cell. The method for printing an insulating coating on the surface of a battery cell provided by an embodiment of the present invention, by setting a side nozzle and adopting a top spraying and side spraying method, can avoid the pole surface from being inverted during the rotation of the battery cell, thereby achieving the effect of completing the printing of the insulating coating on the six surfaces of the battery cell.

[0063] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0065] Figure 1 1 is a flow chart of a method for printing an insulating coating on a battery cell surface according to an embodiment of the present invention;

[0066] Figure 2 yes Figure 1 Specific flow diagram of step S120;

[0067] Figure 3 yes Figure 1 Specific flow diagram of step S150;

[0068] Figure 4 1 is a flow chart of another method for printing an insulating coating on a battery cell surface according to an embodiment of the present invention;

[0069] Figure 5 This is a schematic flow chart of a specific embodiment of a method for printing an insulating coating on a battery cell surface according to an embodiment of the present invention;

[0070] Figure 6 This is a schematic diagram of a specific process of printing and curing a surface in a method for printing an insulating coating on a battery cell surface provided in an embodiment of the present invention;

[0071] Figure 7 yes Figure 6 Specific flow chart of step S210 in FIG. DETAILED DESCRIPTION

[0072] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0073] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0074] As mentioned in the background, with the development of the lithium battery industry, the requirements for the surface strength of battery cells are becoming increasingly stringent. The traditional method of wrapping square battery cells with blue film and applying insulating covers is increasingly unable to meet the needs of industry development. The trend is to replace the original blue film with insulating coating. Currently, there are three main methods for replacing the original blue film with insulating coating: insulating powder coating, UV spray painting, and UV printing.

[0075] The principle of insulation powder spraying is that the tip of the spray gun discharges through an electrode to ionize the air, making the insulation powder statically charged and sprayed onto the grounded workpiece surface. After adsorption, the powder is heated to melt and level to form a dense layer. However, the insulation powder spraying method has the following technical disadvantages: poor coating uniformity, especially poor control of the thickness of the workpiece edge; the impact of low powder application rate on production efficiency. After the charged powder accumulates to a certain thickness, it will be difficult for the powder to continue to accumulate due to the principle of like charges repelling each other; fully automated production requires a very large space, and the dust control and recovery system is complex; for the cover plate pole surface, QR code, and explosion-proof valve area that do not require powder spraying, specially designed shielding jigs are required; the powder spraying yield is low; in addition, the insulation powder spraying process requires melting the powder in a heating furnace. The high temperature in the heating furnace has a negative impact on the performance of the battery cell.

[0076] The principle of UV painting is to use an air spray gun to atomize water-based UV paint and evenly spray it onto the surface of the workpiece, then cure it through ultraviolet light to form a continuous, dense surface coating. However, UV painting has the following technical disadvantages: the coating thickness on the battery cell surface after UV painting is uneven, with large errors; it wastes a lot of ink, as much ink does not reach the battery surface during painting, and paint recovery is difficult, resulting in huge waste; it requires a dust-free environment, an exhaust gas treatment system, and a paint recovery and filtration system, which are complex equipment; masking is still required for areas that do not need to be painted; and after the battery cell is painted, an insulating cover must still be applied, which is costly.

[0077] UV inkjet printing utilizes an inkjet printhead to apply a fine layer of UV ink to the workpiece surface, forming a continuous film. This film is then cured under ultraviolet light to form a dense surface coating. UV printing addresses the technical disadvantages of UV spray painting with insulation powder coating machines, offering uniform coating thickness, high ink utilization, and the elimination of the need for an insulation cover, making it feasible for full automation. However, existing UV printing processes typically utilize a top-down printing method, where the printhead prints from top to bottom. This top-down printing method requires frequent cell flipping and inverting the cell's pole surface to achieve six-sided printing on a square cell. However, as the size and mass of square cells increase, inverting the pole surface of some cells has been shown to cause electrolyte flow. Electrolyte accumulates on the cover, causing corrosion, abnormal self-discharge, and core slippage. This shifts the core support surface from the bottom to the top, deforming the electrode sheet that bears stress on one side. Therefore, inverting the pole surface is not permitted. Consequently, existing UV printing processes cannot achieve six-sided printing on a cell without inverting the pole surface.

[0078] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0079] An embodiment of the present invention provides a method for spraying an insulating coating on the surface of a battery cell. Figure 1A flow chart of a method for spraying an insulating coating on the surface of a battery cell provided in an embodiment of the present invention, which can be performed by a spraying system for spraying an insulating coating on the surface of a battery cell. The battery cell on which the insulating coating is sprayed in the embodiment of the present invention is a square battery cell, which includes 6 surfaces, namely a first surface, a second surface, a third surface, a fourth surface, a fifth surface and a sixth surface, wherein the first surface is the pole surface of the battery cell, the second surface is opposite to the first surface, the third surface is opposite to the sixth surface, and the fourth surface is opposite to the fifth surface. The nozzles used in the method for spraying an insulating coating on the surface of a battery cell provided in an embodiment of the present invention include a top nozzle and a side nozzle, and by using the side nozzle in conjunction with the top nozzle, an insulating coating is formed on each surface of the battery cell in sequence while ensuring that the pole surface of the battery cell is not upside down. As Figure 1 As shown, the method for printing the insulating coating on the surface of the battery cell specifically includes the following steps:

[0080] S110 , placing the battery cell with the third surface facing upward.

[0081] Specifically, the battery cell is first placed with the third surface of the battery cell facing upward, that is, the pole surface is kept at the side and is not turned upside down, so as to facilitate the subsequent UV printing process.

[0082] S120, using a side nozzle to sequentially print ink on the first surface and the second surface at least once, and then curing.

[0083] Specifically, a side nozzle is used to perform at least one ink printing on the two opposite first and second surfaces of the battery cell in the horizontal direction. Printing one surface of the battery cell with one pass of ink is a one-pass printing process; and printing the same surface of the battery cell with multiple passes of ink is a multi-pass printing process. In an embodiment of the present invention, performing a multi-pass printing process on each surface of the battery cell is beneficial to improving the accuracy and color saturation of the printed image. Curing the ink after printing is completed can prevent the ink from sagging due to its own gravity during side printing, thereby making the printed image more solid.

[0084] S130, using the top surface nozzle to print ink on the third surface once, and then curing.

[0085] Specifically, the top surface nozzle is used to perform ink printing and curing on the third surface of the battery cell from top to bottom by top spraying, thereby completing UV printing on the third surface of the battery cell.

[0086] S140 , rotating the battery cell so that the sixth surface faces upward.

[0087] Specifically, after printing on the first, second, and third surfaces of the battery cell, the battery cell is rotated 180° so that the sixth surface of the battery cell remains facing upward. At this point, the battery cell's pole surface, i.e., the first surface, remains sideways and is not inverted, thereby preventing the impact of an inverted pole surface on the battery cell.

[0088] S150, using a side nozzle to sequentially print ink on the fourth surface and the fifth surface at least once, and then curing.

[0089] Specifically, a side nozzle is used to perform at least one PASS printing process on the fourth surface and the fifth surface respectively in the horizontal direction. For example, in an embodiment of the present invention, multiple PASS printing processes are performed on the fourth surface and the fifth surface of the battery cell to ensure the printing effect of the fourth surface and the fifth surface.

[0090] S160: Use the top surface nozzle to print ink on the sixth surface once, and perform curing to complete the printing of the insulating coating on each surface of the battery cell.

[0091] Specifically, the top surface nozzle is used to print and cure the ink on the remaining sixth surface of the battery cell. Thus, without turning the pole surface of the battery cell upside down, the top and side nozzles are used to achieve the effect of printing the insulating coating on the six surfaces of the battery cell.

[0092] The method for printing an insulating coating on the surface of a battery cell provided by an embodiment of the present invention is used to control the nozzle to sequentially form an insulating coating on each surface of the battery cell. The battery cell includes a first surface and a second surface arranged opposite to each other, a third surface and a sixth surface arranged opposite to each other, and a fourth surface and a fifth surface arranged opposite to each other. By placing the third surface of the battery cell with the front side facing upward, the side nozzle is used to sequentially print and cure the ink on the first surface and the second surface at least once, and the top nozzle is used to print and cure the ink once on the third surface. Thereafter, the battery cell is rotated and the sixth surface is placed with the front side facing upward. The side nozzle is used to sequentially print and cure the ink on the fourth surface and the fifth surface at least once, and the top nozzle is used to print and cure the ink on the sixth surface, thereby completing the printing of all six surfaces of the square battery cell. The method for printing an insulating coating on the surface of a battery cell provided by an embodiment of the present invention, by setting a side nozzle and adopting a top spraying and side spraying method, can avoid the pole surface from being inverted during the rotation of the battery cell, thereby achieving the effect of completing the printing of the insulating coating on the six surfaces of the battery cell.

[0093] Optionally, Figure 2 yes Figure 1 The specific flow diagram of step S120 is as follows: Figure 3 yes Figure 1 Detailed flow chart of step S150 in FIG. Based on the above embodiment, see Figure 2 In step S120, ink is sequentially printed on the first surface and the second surface at least once using a side nozzle and then cured, specifically comprising the following steps:

[0094] S121. Use a side nozzle to print ink on the first surface at least once, and then solidify it.

[0095] S122. Use a side nozzle to print ink on the second surface at least once, and then solidify it.

[0096] Specifically, because the battery cell is placed with the third surface facing upward, and the first and second surfaces are both the sides of the battery cell in this direction, a multi-pass printing process is performed horizontally on the first and second surfaces using a side-mounted printhead. Furthermore, during the ink printing process, the ink sprayed onto the battery cell surface is promptly cured to prevent severe sagging due to gravity, which would significantly affect the ink thickness on the battery cell surface.

[0097] See also Figure 3 In step S150, ink is sequentially printed on the fourth surface and the fifth surface at least once using a side nozzle and then cured, specifically comprising the following steps:

[0098] S151. Use a side nozzle to print ink on the fourth surface at least once, and then solidify it.

[0099] S152: Use a side nozzle to print ink on the fifth surface at least once, and then solidify it.

[0100] Specifically, the battery cell is rotated and placed with the sixth surface facing upward. Since the fourth and fifth surfaces are both lateral surfaces of the battery cell in this orientation, a multi-pass printing process is performed horizontally on the fourth and fifth surfaces using a side-mounted printhead. Furthermore, during the printing process, the ink applied to the battery cell surface is promptly cured to prevent severe sagging due to gravity, which would significantly affect the thickness of the ink printed on the battery cell surface.

[0101] It should be noted that to accommodate the side-spraying process proposed in the embodiments of the present invention, certain improvements can be made to the ink. The ink formula is customized and developed based on the material of the prismatic battery cell housing, and the formulation characteristics are continuously adjusted to balance the coating performance with the formulation characteristics. Coating performance primarily includes adhesion, weather resistance, wear resistance, and impact resistance; formulation characteristics primarily include the monomer and photoinitiator system, curing energy threshold, viscosity-surface tension, hardness, and toughness.

[0102] Adjust the ink formulation in single-color, high-thickness coating printing scenarios to make the ink have higher viscosity and larger particle size, and deliver more ink during printing.

[0103] Optionally, Figure 4 This is a flow chart of another method for printing an insulating coating on the surface of a battery cell provided by an embodiment of the present invention. Figure 4 As shown, the method for printing the insulating coating on the surface of the battery cell specifically includes the following steps:

[0104] S110 , placing the battery cell with the third surface facing upward.

[0105] S170: Use the top surface nozzle to spray ink on the first edge of the third surface and perform pre-curing.

[0106] Specifically, a top surface nozzle is first used to perform supplementary spraying and pre-curing on the two longer first edges of the third surface facing upward, to prevent the risk of white exposure at the first edges between the surfaces after the printing of the six surfaces of the battery cell is completed, thereby improving the overall printing effect of the battery cell and ensuring that the battery cell passes the insulation withstand voltage test.

[0107] S121. Use a side nozzle to print ink on the first surface at least once, and then solidify it.

[0108] S122. Use a side nozzle to print ink on the second surface at least once, and then solidify it.

[0109] S130, using the top surface nozzle to print ink on the third surface once, and then curing.

[0110] S140 , rotating the battery cell so that the sixth surface faces upward.

[0111] S180: Use the top surface nozzle to spray ink on the first edge of the sixth surface and perform pre-curing.

[0112] Specifically, after the sixth surface of the battery cell is rotated to face forward, the top nozzle is used to perform supplementary spraying and pre-curing on the two longer first edges of the sixth surface through top spraying, thereby ensuring that no white spots appear on the first edges between the battery cell surfaces, improving the overall printing effect of the battery cell, and allowing the battery cell to successfully pass the insulation withstand voltage test.

[0113] S190, using a side nozzle to spray ink on the second edge of the fourth surface, and perform pre-curing.

[0114] Specifically, after the sixth surface of the battery cell is rotated to face upward, the fourth surface is located on the side of the battery cell. Before printing on the fourth surface, the four second edges of the fourth surface that are shorter than the first edges are firstly supplementally sprayed and pre-cured using a side nozzle.

[0115] S151. Use a side nozzle to print ink on the fourth surface at least once, and then solidify it.

[0116] S200, using a side nozzle to spray ink on the second edge of the fifth surface and perform pre-curing; wherein the length of the second edge is smaller than the length of the first edge.

[0117] Specifically, the fifth surface is also located on the side of the battery cell. Before printing on the fifth surface, the four second edges of the fifth surface that are shorter than the first edges are firstly sprayed and pre-cured using a side nozzle to ensure that the second edges between the surfaces do not show any white spots after printing.

[0118] S152: Use a side nozzle to print ink on the fifth surface at least once, and then solidify it.

[0119] S160: Use the top surface nozzle to print ink on the sixth surface once, and perform curing to complete the printing of the insulating coating on each surface of the battery cell.

[0120] Optionally, based on the above embodiments, step S121, step S122, step S151 and step S152 specifically include the following steps:

[0121] The step S121 of printing ink on the first surface at least once using a side nozzle and curing the ink may specifically include:

[0122] Using a side nozzle to print ink and pre-curing on the first surface, and repeating the process twice;

[0123] The side nozzle is used to print ink on the first surface and perform final curing.

[0124] The step S122 of printing ink on the second surface at least once using the side nozzle and curing the ink may specifically include:

[0125] Use the side nozzle to print ink and pre-curing on the second surface, and repeat the process twice;

[0126] The side nozzle is used to print ink on the second surface and perform final curing.

[0127] The step S151 of printing ink on the fourth surface at least once using the side nozzle and curing the ink may specifically include:

[0128] The ink is sprayed and pre-cured on the fourth surface using a side nozzle, and the process is repeated twice;

[0129] The ink is sprayed and finally cured on the fourth surface using a side nozzle.

[0130] The step S152 of printing ink on the fifth surface at least once using the side nozzle and curing the ink may specifically include:

[0131] The ink is sprayed and pre-cured on the fifth surface using a side nozzle, and the process is repeated twice;

[0132] The fifth surface is printed with ink and finally cured using a side nozzle.

[0133] Specifically, in the technical process development route for realizing the overall printing of the six surfaces of a square battery cell using a side-spraying process, the process steps for printing and pre-curing the first surface, the second surface, the fourth surface, and the fifth surface are the same. In this embodiment, the process of printing the first surface is taken as an example for explanation, and the printing process of other surfaces is not described in detail here. When the battery cell is placed with the third surface facing upward, the first surface serves as the side of the battery cell, so a side nozzle is used to print the first surface. A smaller number of nozzles can be used to print ink on the first surface, and the ink sprayed onto the first surface is pre-cured with a certain pre-curing energy, and the pre-curing is continued for a period of time, so that the first layer of ink printed is initially fixed. The above-mentioned ink printing and pre-curing operation is repeated twice, and then the side nozzle is used to print ink on the first surface again, and the last layer of ink sprayed onto the first surface is final-cured with a corresponding final-curing energy, and the final-curing is continued for a period of time, thereby completing the printing operation on the first surface of the battery cell. By adopting a multi-pass printing process, the printing effect on the battery cell surface can be optimized, which is beneficial to improving the accuracy and color saturation of the printed image.

[0134] A feasible embodiment, Figure 5 This is a flow chart of a specific embodiment of a method for printing an insulating coating on a battery cell surface provided by an embodiment of the present invention. Figure 5 As shown, the method for printing the insulating coating on the surface of the battery cell specifically includes the following steps:

[0135] S1. Place the third surface of the battery cell facing upwards;

[0136] S2, use 4 top surface nozzles to spray ink on the first edge of the third surface at a rate of 1000mJ / cm 2 The pre-curing energy lasts for 2.3 seconds;

[0137] S3, use two side nozzles to print the first ink on the first surface at a rate of 1000mJ / cm2 The pre-curing energy lasts for 2.3 seconds;

[0138] S4, use two side nozzles to print the ink on the first surface for the second time, and print the ink at 1000mJ / cm 2 The pre-curing energy lasts for 2.3 seconds;

[0139] S5, use two side nozzles to print ink on the first surface for the third time, and print at 22400mJ / cm 2 The final curing energy lasts for 3.1 seconds;

[0140] S6, use two side nozzles to print the first ink on the second surface at 1000mJ / cm 2 The pre-curing energy lasts for 3.1 seconds;

[0141] S7, use two side nozzles to print the ink on the second surface for the second time, and print the ink at 1000mJ / cm 2 The pre-curing energy lasts for 2.3 seconds;

[0142] S8, use two side nozzles to print the ink on the second surface for the third time, and print the ink at 1000mJ / cm 2 The final curing energy lasts for 2.3 seconds;

[0143] S9, use 12 top surface nozzles to print ink on the third surface once, and print at 22400mJ / cm 2 The final curing energy lasts for 4.36s;

[0144] S10, rotating the battery cell so that the sixth surface faces upward;

[0145] S11, use 4 top surface nozzles to spray ink on the first edge of the sixth surface at 22400mJ / cm 2 The final curing energy lasts for 2.3 seconds;

[0146] S12, use 4 side nozzles to spray ink on the second edge of the fourth surface at a rate of 1000mJ / cm 2 The pre-curing energy lasts for 1.8 seconds;

[0147] S13, use two side nozzles to print ink on the fourth surface for the first time, and print at 1000mJ / cm 2 The pre-curing energy lasts for 1.8 seconds;

[0148] S14, use two side nozzles to print ink on the fourth surface for the second time, and print at 1000mJ / cm 2The pre-curing energy lasts for 1.8 seconds;

[0149] S15, use two side nozzles to print ink on the fourth surface for the third time, and print at 22400mJ / cm 2 The final curing energy lasts for 1.8 seconds;

[0150] S16, use 4 side nozzles to spray ink on the second edge of the fifth surface at 1000mJ / cm 2 The pre-curing energy lasts for 1.8 seconds;

[0151] S17, use two side nozzles to print ink on the fifth surface for the first time, and print at 1000mJ / cm 2 The pre-curing energy lasts for 1.8 seconds;

[0152] S18, use two side nozzles to print ink on the fifth surface for the second time, and print at 1000mJ / cm 2 The pre-curing energy lasts for 1.8 seconds;

[0153] S19, use two side nozzles to print ink on the fifth surface for the third time, and print at 22400mJ / cm 2 The final curing energy lasts for 1.8 seconds;

[0154] S20, use 18 top surface nozzles to print ink on the sixth surface once, and print at 22400mJ / cm 2 The final curing energy lasts for 3.2 seconds.

[0155] Optionally, Figure 6 This is a schematic diagram of the specific process of printing and curing the surface of a battery cell surface insulating coating printing method provided by an embodiment of the present invention. Figure 6 As shown, based on the above embodiments, the method of printing ink on the surface of the battery cell and curing it in step S120, step S130, step S140 and step S150 specifically includes the following steps:

[0156] S210 , obtaining a position coordinate matrix of the area to be printed on the surface of the battery cell.

[0157] Specifically, the area to be printed is the area on each surface of the battery cell where ink printing is allowed. Exemplarily, the area to be printed includes the area except the explosion-proof valve, pole and QR code area on the first surface. Since the explosion-proof valve, pole and QR code area on the pole surface of the battery cell cannot be printed with ink, it is necessary to remove the above-mentioned non-printable area when determining the area to be printed on each surface of the battery cell, and obtain the edge contour of the area to be printed, so as to control the nozzle not to print ink outside the contour of the battery cell surface, avoid poor appearance caused by ink splashing, especially the full weld edge of the top cover; and avoid the offset of the area to be printed caused by the tolerance of the clamping position, and avoid the situation where the ink is not partially covered or there is local flying ink. The area to be printed includes a plurality of position points arranged in an array, and the information obtained about the area to be printed includes the position coordinate dot matrix of each position point in the area.

[0158] S220 , rasterizing the image of the area to be printed according to the position coordinate dot matrix, and generating nozzle position information and ink volume information; wherein both the nozzle position information and the ink volume information have a mapping relationship with the position coordinate dot matrix.

[0159] Specifically, using RIP software, the two-dimensional image of the area to be printed can be rasterized to obtain the height information corresponding to the position coordinate dot matrix in the area to be printed, and the information mapping from the image information of the area to be printed to the print head printing dot matrix can be realized, thereby obtaining the nozzle position information and the corresponding ink volume information during the process of printing on the battery cell surface, which is conducive to improving the accuracy of printing.

[0160] S230 : Control the ink path system to deliver ink to the nozzle according to the nozzle position information and the ink quantity information.

[0161] Specifically, according to the determined position of the nozzle during the printing process and the corresponding amount of ink ejected at each position, the ink path system is controlled to deliver a corresponding amount of ink to the nozzle at the corresponding printing position, thereby accurately completing the ink printing on the surface of the battery cell.

[0162] S240, controlling the nozzle to print ink onto the surface of the battery cell and solidify the ink, and performing at least one printing and solidifying operation to complete the printing of the insulating coating on the surface of the battery cell.

[0163] Specifically, the corresponding top nozzle or side nozzle is controlled to print ink onto the surface of the battery cell and solidify it in time. By repeatedly performing a multi-pass printing process on the same surface for multiple times, the printing effect of the battery cell can be effectively improved.

[0164] Optionally, Figure 7 yes Figure 6 Specific flow chart of step S210 in FIG. Based on the above embodiment, as Figure 7As shown, the step S210 of obtaining the position coordinate dot matrix of the area to be printed on the surface of the battery cell includes:

[0165] S211. Calibrate the position coordinate system of the printing system and the position coordinate system of the visual positioning system, and generate a position calibration file.

[0166] Specifically, the position calibration file represents the correspondence between the position coordinates of the printing system and the position coordinates of the vision positioning system. For the battery cells undergoing initial printing, the calibration tool calibrates the position coordinate systems of the printing system and the vision positioning system, and generates a position calibration file.

[0167] S212 , collecting an image to be processed on the surface of the battery cell, performing image processing on the image to be processed, and integrating the image into a position calibration file.

[0168] Specifically, a visual camera is used to capture images of the corresponding surface of the battery cell. The images are processed using an image algorithm and integrated into a position calibration file. For example, the position calibration file can be a C / C++ X64 DLL file, which is not limited here.

[0169] S213 , calling the position calibration file to perform image processing on the image to be processed, generating a rendering of the area to be printed, and obtaining a position coordinate dot matrix of the area to be printed.

[0170] Specifically, the corresponding interface in the position calibration file is called to process the image to be processed to obtain the corresponding rendering image, which can then determine the position coordinate dot matrix of the area to be printed. The rendering image of the area to be printed is then called to control the print head to print, so that the print head can accurately print the battery cell surface according to the area to be printed, completely covering the area to be printed and avoiding the non-printable areas.

[0171] Optionally, based on the above embodiments, controlling the nozzle to print ink onto the surface of the battery cell and solidify the ink in step S240, and performing at least one printing and curing operation, specifically includes the following steps:

[0172] Control a first preset number of nozzles to perform multiple printing and curing operations on the surface of the battery cell; or control a second preset number of nozzles to perform one printing and curing operation on the surface of the battery cell; wherein the sum of the first preset number of nozzles used for the multiple printing and curing operations is equal to the second preset number of nozzles.

[0173] Specifically, the printhead includes a plurality of printhead modules, and each printhead module includes a plurality of nozzles. For example, a printhead module may include 2000 nozzles. When determining the printhead position information and ink volume information, the number of printhead modules used and the number of nozzles used on each printhead module may be determined at the same time. By controlling multiple nozzles to print in coordination, high-load printing operations can be achieved, and appropriate printhead waveforms and printhead operating voltages can be selected according to the ink to ensure that the ejected ink droplets are round and complete, and to avoid the risk of abnormal ink droplet shapes being easily retained on the printhead surface and causing printhead clogging. For example, it can be ensured that the single-point standard ink droplet size ejected by each nozzle can reach 40PL, which is not limited here.

[0174] In the process of printing on the surface of the battery cell, a smaller first preset number of nozzles can be used for multiple printing and curing operations, or a larger second preset number of nozzles can be used for one printing and curing operation, and the sum of the first preset number of nozzles used for multiple printing and curing operations is equal to the second preset number of nozzles. For example, the first preset number can be 2, and the second preset number can be 6, that is, 2 nozzles can be used to perform 3 printing and curing operations on the surface of the battery cell, or 6 nozzles can be used to perform 1 printing and curing operation. It should be noted that in the case of using 6 nozzles to perform 1 printing and curing operation, the 6 nozzles can also be divided into zones, and the nozzles in different zones can be controlled separately to perform printing and curing operations.

[0175] Optionally, based on the above embodiments, controlling the ink path system to deliver ink to the nozzle in step S230 specifically includes the following steps:

[0176] The preset temperature in the ink tube of the ink system is regulated to keep the preset temperature at a constant temperature.

[0177] Specifically, the ink tube is heated by a heating device in the ink path system to adjust a preset temperature of the ink tube so that the ink tube is kept at a constant preset temperature and ink is uniformly delivered to the nozzle.

[0178] The ink tube of the ink path system is controlled to maintain a high-precision negative pressure state so that the ink path system can deliver ink to the nozzle according to the ink volume information.

[0179] Specifically, a multi-stage circulating ink supply is achieved through the ink path system, and the pressure in the ink tube is adjusted to maintain a high-precision negative pressure state in the ink tube, thereby controlling the ink delivery to the nozzle for ejection according to the corresponding ink volume.

[0180] An embodiment of the present invention also provides a system for printing an insulating coating on the surface of a battery cell. This system is used to perform the method for printing an insulating coating on the surface of a battery cell provided in any of the above embodiments, and has the same beneficial effects as the method. Specifically, by providing a side nozzle and using a combination of top and side nozzles, the polarity can be prevented from being inverted during the rotation of the battery cell, achieving the effect of printing the insulating coating on all six surfaces of the battery cell.

[0181] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for printing an insulating coating on a battery surface, characterized in that: Used to control the nozzle to sequentially form an insulating coating on each surface of the battery core; wherein the battery core includes a first surface, a second surface, a third surface, a fourth surface, a fifth surface and a sixth surface, and the first surface is a pole surface; the nozzle includes a top nozzle and a side nozzle; The method for printing the insulating coating on the surface of the battery cell comprises: Place the third surface of the battery cell with its front side facing upward; Using the side nozzle to sequentially print ink on the first surface and the second surface at least once, and then perform curing; Using the top surface nozzle to print ink once on the third surface, and then curing the ink; Rotating the battery cell so that the sixth surface faces upward; Using the side nozzle to sequentially print ink on the fourth surface and the fifth surface at least once, and then perform curing; Using the top surface nozzle to print ink on the sixth surface once, and then curing the ink to complete the printing of the insulating coating on each surface of the battery cell; The second surface is opposite to the first surface, the third surface is opposite to the sixth surface, and the fourth surface is opposite to the fifth surface.

2. The method for printing an insulating coating on a battery surface according to claim 1, characterized in that: The step of using the side nozzle to sequentially print ink on the first surface and the second surface at least once and then curing the ink comprises: Using the side nozzle to print ink on the first surface at least once, and then curing the ink; Using the side nozzle to print ink on the second surface at least once, and then curing the ink; The step of using the side nozzle to sequentially print ink on the fourth surface and the fifth surface at least once and then curing the ink comprises: Using the side nozzle to print ink on the fourth surface at least once, and then curing the ink; The side nozzle is used to print ink on the fifth surface at least once, and then the ink is cured.

3. The method for printing the insulating coating on the surface of the battery cell according to claim 2, characterized in that: Before the side nozzle is used to print ink on the first surface at least once, the method further includes: Using the top surface nozzle to spray ink on the first edge of the third surface, and perform pre-curing; Before the side nozzle is used to print ink on the fourth surface at least once, the method further includes: Using the top surface nozzle to spray ink on the first edge of the sixth surface, and perform pre-curing; Using the side nozzle to spray ink on the second edge of the fourth surface, and perform pre-curing; Before the side nozzle is used to print ink on the fifth surface at least once, the method further includes: Using the side nozzle to spray ink on the second edge of the fifth surface, and perform pre-curing; Wherein, the length of the second edge is smaller than the length of the first edge.

4. The method for printing an insulating coating on a battery surface according to claim 2, characterized in that: The step of using the side nozzle to print ink on the first surface at least once and then curing the ink comprises: Using the side nozzle to print ink and pre-curing the first surface, and repeating the process twice; Using the side nozzle to print ink on the first surface and perform final curing; or, The step of using the side nozzle to print ink on the second surface at least once and then curing the ink comprises: Using the side nozzle to print ink and pre-curing the second surface, and repeating the process twice; Using the side nozzle to print ink on the second surface and perform final curing; or, The step of using the side nozzle to print ink on the fourth surface at least once and then curing the ink comprises: Using the side nozzle to print ink and pre-curing the fourth surface, and repeating the process twice; Using the side nozzle to print ink and perform final curing on the fourth surface; or, The step of using the side nozzle to print ink on the fifth surface at least once and then curing the ink comprises: Using the side nozzle to print ink and pre-curing the fifth surface, and repeating the process twice; The side nozzle is used to print ink and perform final curing on the fifth surface.

5. The method for printing an insulating coating on the surface of a battery cell according to any one of claims 1 to 4, characterized in that: The method of printing ink on the surface of the battery cell and curing the ink comprises: Obtaining a position coordinate matrix of an area to be printed on the surface of the battery cell; The image of the area to be printed is rasterized according to the position coordinate dot matrix, and the nozzle position information and the ink volume information are generated; wherein the nozzle position information and the ink volume information are mapped to the position coordinate dot matrix; According to the nozzle position information and the ink quantity information, controlling the ink path system to deliver ink to the nozzle; The nozzle is controlled to spray ink onto the surface of the battery cell and solidify the ink, and at least one spray printing and solidification operation is performed to complete the spray printing of the insulating coating on the surface of the battery cell.

6. The method for printing the insulating coating on the surface of the battery cell according to claim 5, characterized in that: The step of obtaining a position coordinate dot matrix of an area to be printed on the surface of the battery cell comprises: Calibrate the position coordinate system of the printing system and the position coordinate system of the visual positioning system, and generate a position calibration file; Collecting an image to be processed of the surface of the battery cell, performing image processing on the image to be processed and integrating the image into the position calibration file; The position calibration file is called to perform image processing on the image to be processed, to generate a rendering of the area to be printed, and to obtain the position coordinate dot matrix of the area to be printed.

7. The method for printing an insulating coating on a battery surface according to claim 6, characterized in that: The area to be printed includes the area except the explosion-proof valve, the pole and the two-dimensional code area on the first surface.

8. The method for printing an insulating coating on the surface of a battery cell according to claim 5, characterized in that: The nozzle comprises a plurality of nozzle modules, each of which comprises a plurality of nozzles; The step of controlling the nozzle to print ink onto the surface of the battery cell and solidify the ink, and performing at least one printing and solidification operation, includes: Controlling a first preset number of the nozzles to perform multiple printing and curing operations on the surface of the battery cell; Alternatively, controlling a second preset number of nozzles to perform a printing and curing operation on the surface of the battery cell; Wherein, the sum of the first preset number of the nozzles used in multiple printing and curing operations is equal to the second preset number of the nozzles.

9. The method for printing an insulating coating on the surface of a battery cell according to claim 5, characterized in that: The ink circuit system is controlled to deliver ink to the nozzle, including: Regulating a preset temperature in an ink tube of the ink circuit system so that the preset temperature is maintained at a constant temperature; The ink tube of the ink path system is controlled to maintain a high-precision negative pressure state, so that the ink path system delivers ink to the nozzle according to the ink quantity information.

10. A printing system for insulating coating on the surface of a battery cell, characterized in that: A method for printing an insulating coating on the surface of a battery cell as described in any one of claims 1 to 9.

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