Roller, film coating equipment and film coating method

Abstract

The embodiment of the invention provides a roller, film coating equipment and a film coating method. The roller comprises a shaft core part and a rolling part arranged on the shaft core part in a sleeving mode. The rolling part comprises at least three subsections arranged in the circumferential direction of the shaft core part, the shapes of the peripheral faces of the subsections comprise an arc-shaped convex face, an arc-shaped concave face and a cylindrical face, and the shapes of the peripheral faces of every two adjacent subsections are different. In the axial direction of the shaft core part, the middle of the arc-shaped convex face protrudes in the direction away from the shaft core part relative to the two ends of the arc-shaped convex face, and the middle of the arc-shaped concave face sinks in the direction close to the shaft core part relative to the two ends of the arc-shaped concave face. According to the embodiment of the invention, the rolling part of the roller comprises a plurality of subsections with different peripheral shapes, so that the requirements of different planeness of a plurality of battery cells can be met. The arc-shaped convex surface, the arc-shaped concave surface and the cylindrical surface are used for flattening the protective film and the concave area / convex area of the battery cell, air between the protective film and the battery cell is exhausted, and the film coating reliability and the film coating yield are improved.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a roller, a film coating device and a film coating method. Background Art

[0002] With the rapid development of economy and technology, power batteries are being used more and more widely. The surface of the power battery cell usually needs to be coated, and the protective film is coated on the outside of the cell. The protective film can ensure the insulation between power batteries, protect the cell from the influence of the external environment, and reduce cell damage and short circuit.

[0003] There are two ways to coat power batteries: manual coating and automatic coating by coating equipment. The quality of manual coating is poor, which affects subsequent assembly and is difficult to guarantee the performance of the battery cell. The automatic coating by coating equipment uses upper and lower rollers to roll the protective film so that the protective film is close to the surface of the battery cell, and uses the upper and lower rollers to coat the two large surfaces of the battery cell. However, it is difficult for the automatic coating equipment to completely expel the air between the protective film and the battery cell, and the yield is low. Summary of the invention

[0004] The embodiments of the present application provide a roller, a coating device and a coating method to discharge the air between the protective film and the battery cell, thereby improving the coating yield.

[0005] In a first aspect, an embodiment of the present application provides a roller for coating a plurality of battery cells, the roller comprising: an axis core portion, and a rolling portion sleeved on the axis core portion;

[0006] The rolling portion includes at least three sections arranged along the circumference of the shaft core, the shapes of the outer circumferences of the at least three sections include an arcuate convex surface, an arcuate concave surface and a cylindrical surface, and the shapes of the outer circumferences of two adjacent sections are different;

[0007] Among them, along the axial direction of the shaft core, the middle part of the arcuate convex surface protrudes away from the shaft core relative to the two ends of the arcuate convex surface, and the middle part of the arcuate concave surface is concave towards the direction close to the shaft core relative to the two ends of the arcuate concave surface.

[0008] In some possible implementations, one end of two adjacent subsections adjacent to each other is transitioned in an arc shape.

[0009] In some possible implementations, the rolling portion is made of a silicone material.

[0010] In some possible implementations, along the axial direction of the shaft core, two opposite ends of the rolling portion are in the shape of a circular ring or an elliptical ring.

[0011] In some possible implementations, the number of the subdivisions is an integer multiple of 3;

[0012] Along the circumference of the shaft core, the shapes of the outer peripheral surfaces of all the divisions are arranged cyclically, and are arc-shaped convex surface, arc-shaped concave surface and cylindrical surface in sequence, or arc-shaped convex surface, cylindrical surface and arc-shaped concave surface in sequence.

[0013] In some possible implementations, the rolling section is divided into a plurality of subsections.

[0014] In some possible implementations, the chord length corresponding to the central angle of each of the sub-portions is the minimum value of an average value of widths of convex regions and an average value of widths of concave regions of the coating surfaces of the plurality of battery cells.

[0015] In some possible implementations, the depth of the lowest point of the arc-shaped concave surface is the maximum value of the convex heights of the convex areas of the coating surfaces of the plurality of battery cells.

[0016] In some possible implementations, the height of the highest point of the arc-shaped convex surface is the maximum value of the depression depths of the depression areas of the coating surfaces of the plurality of battery cells.

[0017] In some possible implementations, the compression amount of the rolling portion is an average value of the depression depths of the depression areas of the plurality of battery cells, or an average value of the protrusion heights of the protrusion areas of the plurality of battery cells.

[0018] In some possible implementations, along the axial direction of the shaft core, the lengths of the sections are the same.

[0019] In a second aspect, an embodiment of the present application provides a film coating device, comprising: a conveying mechanism, the roller as described above, and a driving mechanism;

[0020] The conveying mechanism is used to convey the battery core, and the driving mechanism is connected to the roller wheel for driving the roller wheel to rotate.

[0021] In a third aspect, an embodiment of the present application provides a coating method, comprising:

[0022] The detection device detects the flatness of the coating surface of the plurality of battery cells to be coated, and obtains the flatness data of the coating surface;

[0023] A roller is formed according to the flatness data, the roller comprising: an axial core portion, and a rolling portion sleeved on the axial core portion; the rolling portion comprises at least three sub-portions arranged along the circumference of the axial core portion, the outer peripheral surfaces of the at least three sub-portions have shapes comprising an arcuate convex surface, an arcuate concave surface and a cylindrical surface, and the outer peripheral surfaces of two adjacent sub-portions have different shapes; wherein, along the axial direction of the axial core portion, the middle portion of the arcuate convex surface is convex in a direction away from the axial core portion relative to the two ends of the arcuate convex surface, and the middle portion of the arcuate concave surface is concave in a direction close to the axial core portion relative to the two ends of the arcuate concave surface;

[0024] The conveying mechanism conveys the battery core to contact with the protective film, and uses the roller to press the protective film onto the battery core.

[0025] In some possible implementations, the flatness data includes a flatness gradient, and when the protective film is pressed onto the battery cell, the rotation speed of the roller is adjusted in real time according to the flatness gradient.

[0026] In some possible implementations, the following further includes:

[0027] The detection device detects the coating effect of the battery core and optimizes the relationship between the rotation speed of the roller and the flatness gradient.

[0028] The roller, coating equipment and coating method in the embodiment of the present application use a roller to coat multiple battery cells, and the roller includes an axial core portion and a rolling portion, and the rolling portion is sleeved on the axial core portion. The rolling portion includes at least three sections arranged along the circumference of the axial core portion, and the shapes of the outer peripheral surfaces of at least three sections include arc-shaped convex surfaces, arc-shaped concave surfaces and cylindrical surfaces, and the shapes of the outer peripheral surfaces of two adjacent sections are different. Among them, along the axial direction of the axial core portion, the middle part of the arc-shaped convex surface bulges away from the axial core portion relative to the two ends of the arc-shaped convex surface, and the middle part of the arc-shaped concave surface is concave relative to the two ends of the arc-shaped concave surface toward the direction close to the axial core portion. The rolling portion includes multiple sections with different peripheral shapes, which can be compatible with the requirements of different flatness of multiple battery cells. The arc-shaped convex surface, the arc-shaped concave surface and the cylindrical surface are used to flatten the recessed area / convex area of ​​the protective film and the battery cell, and the air between the protective film and the battery cell is discharged, thereby improving the coating reliability and coating yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0030] Figure 1 It is a schematic diagram of a roller in the related art;

[0031] Figure 2 A schematic diagram of the battery cell coating provided in this application;

[0032] Figure 3 A schematic diagram of the coating surface of the battery cell provided in this application;

[0033] Figure 4 A schematic diagram of one direction of the first division provided for this application;

[0034] Figure 5 A schematic diagram of another orientation of the first subdivision provided for this application;

[0035] Figure 6 A schematic diagram of another direction of the first subdivision provided for this application;

[0036] Figure 7 A perspective view of the first subdivision provided for this application;

[0037] Figure 8 A schematic diagram of one direction of the second division provided for this application;

[0038] Fig. 9 A schematic diagram of another orientation of the second subdivision provided for this application;

[0039] Fig.10 A schematic diagram of another direction of the second division provided for this application;

[0040] Fig.11 A perspective view of the second subdivision provided for this application;

[0041] Fig.12 A schematic diagram of one direction of the third division provided for this application;

[0042] Fig.13 A schematic diagram of another orientation of the third division provided for this application;

[0043] Fig.14 A schematic diagram of another direction of the third division provided for this application;

[0044] Fig.15 A perspective view of the third subdivision provided for this application;

[0045] Fig.16 A schematic diagram of the chord length of the subdivision provided for this application;

[0046] Fig.17 A flow chart of the coating method provided for this application;

[0047] Fig.18 A process diagram of the coating method provided for this application;

[0048] Fig.19 A simplified flow chart of the coating method provided in this application.

[0049] Description of reference numerals:

[0050] 10-battery cell;

[0051] 11-capsular surface;

[0052] 12-depressed area;

[0053] 13- raised area;

[0054] 20- roller;

[0055] 21- shaft core;

[0056] 22-Division;

[0057] 23-arc convex surface;

[0058] 24- arc-shaped concave surface;

[0059] 25-cylinder;

[0060] 30-Protective film. DETAILED DESCRIPTION

[0061] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0062] It is difficult to completely exhaust the air between the protective film and the battery cell in the related art, and the film coating yield is low. The reasons are: Figure 1 and Figure 2 When coating the battery cell 10 with the protective film 30 , a cylindrical roller 20 is often used. The roller 20 rolls the protective film 30 so that the protective film 30 is closely attached to the coating surface 11 of the battery cell 10 .

[0063] However, see Figure 1 and Figure 3 , the coating surface 11 of the battery cell 10 often has unevenness. Figure 2 The cylindrical roller 20 shown cannot flatten the concave area 12 and the convex area 13, so that the air between the protective film 30 and the battery cell 10 is difficult to be emptied, resulting in bubbles or wrinkles, and the coating yield is low.

[0064] The embodiment of the present application provides a roller, which includes at least three sections, and the shapes of the outer circumferences of these sections include arc-shaped convex surfaces, arc-shaped concave surfaces, and cylindrical surfaces, and the shapes of the outer circumferences of two adjacent sections are different, so that the roller can be compatible with the requirements of different flatness of multiple battery cells. The arc-shaped convex surface, arc-shaped concave surface, and cylindrical surface are used to flatten the recessed area / convex area of ​​the protective film and the battery cell, and the air between the protective film and the battery cell is discharged, thereby improving the reliability and yield of the film.

[0065] The technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0066] The present application embodiment provides a coating device for coating a plurality of battery cells. Figure 1 As shown, the battery cell 10 is, for example, a square lithium battery cell, and the protective film 30 coated thereon is a blue film, which is blue in color and made of polyester materials such as PET and PVC. The battery cell 10 is placed flat on the coating device, that is, the large surface of the battery cell 10 is in contact with the coating device, and the large surface of the battery cell 10 refers to the surface of the battery cell 10 with the largest area.

[0067] See also Figures 4 to 17 The coating device includes a conveying mechanism, a roller 20 and a driving mechanism, wherein the conveying mechanism is used to convey the battery cell 10, and the driving mechanism is connected to the roller 20 to drive the roller 20 to rotate. Specifically, the conveying mechanism performs loading and unloading of the battery cell 10, and conveys the battery cell 10 to the coating station.

[0068] The driving mechanism is in transmission connection with the roller 20, and the driving mechanism can drive the roller 20 to rotate, and the speed of the roller 20 can be adjusted. The driving mechanism includes, for example, a servo motor. The roller 20 can rotate and move in a direction close to or away from the coating surface 11 of the battery cell 10, thereby applying pressure to the large surface of the battery cell 10, pressing the protective film 30 onto the coating surface 11 of the battery cell 10, and achieving the coating of the battery cell 10.

[0069] The film coating equipment also includes an unwinding mechanism, a film stretching mechanism, a film pulling mechanism, and a film cutting mechanism. Among them, the unwinding mechanism is used to place the protective film 30 to provide a centrifugal protective film 30 or a common protective film 30. The film stretching mechanism is used to tighten the protective film 30. The film pulling mechanism is used to pull the end of the protective film 30 to the film coating station and adsorb the protective film 30. The film pulling mechanism includes, for example, a manipulator and a negative pressure conveyor belt. The film cutting mechanism is used to cut the protective film 30. For example, the film cutting mechanism includes a cylinder and a cutter connected to the cylinder. The film coating equipment also includes a frame, which provides support. The unwinding mechanism, the film stretching mechanism, the film pulling mechanism, the film cutting mechanism, the conveying mechanism, the roller 20 and the driving mechanism can all be arranged on the frame.

[0070] It is understandable that the coating equipment can coat multiple battery cells 10, and the flatness of the coating surface 11 of each battery cell 10 in the multiple battery cells 10 to be coated is not exactly the same. The coating surface 11 of some battery cells 10 is flat, and the coating surface 11 of some battery cells 10 has a recessed area 12, that is, the coating surface 11 of some battery cells 10 is concave, and the coating surface 11 of some battery cells 10 has a raised area 13, that is, the coating surface 11 of some battery cells 10 is convex. The coating surface 11 of some battery cells 10 also has a recessed area 12 and a raised area 13. The flatness of the coating surface 11 of multiple battery cells 10 can be measured by a measuring device to obtain a certain amount of flatness data, and the measuring device includes, for example, a 3D camera.

[0071] According to the measured flatness data, the degree of concavity and convexity of the coating surface 11 of the battery cell 10 can be determined. The degree of concavity of the coating surface 11 of the battery cell 10 includes the concavity depth, width and gradient of the concavity area 12. The concavity depth of the concavity area 12 represents the degree of concavity of the concavity area 12, which is the concavity of the concavity area 12 along the thickness direction of the battery cell 10 ( Figure 4 The dimensions of the Z direction are as shown in Figure 4 The width of the concave region 12 represents the distribution range of the concave region 12, which is the width of the concave region 12 along the moving direction of the battery cell 10 ( Figure 4 The dimensions of the X direction are shown as Figure 4 The gradient of the concave region 12 represents the slope of the concave region 12, that is, whether the concave region 12 changes rapidly or slowly.

[0072] The convexity of the coating surface 11 of the battery cell 10 includes the convexity height, width and gradient of the convex area 13. The convexity height of the convex area 13 represents the convexity of the convex area 13, which is the size of the convex area 13 along the thickness direction of the battery cell 10, such as Figure 4 The width of the raised area 13 represents the distribution range of the raised area 13, which is the size of the raised area 13 along the moving direction of the battery cell 10, as shown in FIG. Figure 4The gradient of the raised area 13 represents the slope of the raised area 13 , that is, the raised area 13 changes rapidly or slowly. The gradient of the raised area 13 and the gradient of the recessed area 12 form the flatness gradient of the coating surface 11 of the battery cell 10 .

[0073] See also Figures 5 to 15 The roller 20 includes an axis core portion 21 and a rolling portion sleeved on the axis core portion 21; the rolling portion includes at least three sections 22 arranged along the circumference of the axis core portion 21, and the shapes of the outer peripheral surfaces of the at least three sections 22 include an arcuate convex surface 23, an arcuate concave surface 24 and a cylindrical surface 25, and the shapes of the outer peripheral surfaces of two adjacent sections 22 are different; wherein, along the axial direction of the axis core portion 21, the middle portion of the arcuate convex surface 23 protrudes in a direction away from the axis core portion 21 relative to the two ends of the arcuate convex surface 23, and the middle portion of the arcuate concave surface 24 is recessed in a direction close to the axis core portion 21 relative to the two ends of the arcuate concave surface 24.

[0074] Specifically, the shaft core 21 may be cylindrical, for example, the shaft core 21 may be cylindrical or elliptical. Figure 7 , Fig.11 , Fig.15 The M direction shown in FIG. 1 and the circumferential direction of the shaft core 21 are as shown in FIG. Figure 4 , Figure 8 , Fig.12 The material of the shaft core 21 can be metal, so that the roller 20 has a certain hardness and can provide pressure to the battery cell 10 and the protective film 30.

[0075] The rolling part is sleeved outside the shaft core 21, and the rolling part and the shaft core 21 are relatively fixed, for example, the two are interference fit. Along the axial direction of the shaft core 21, both ends of the shaft core 21 extend outward from the rolling part, so that the shaft core 21 is connected to an external drive mechanism to drive the shaft core 21 to rotate. The material of the rolling part includes silicone material, so that the rolling part is soft and has a certain amount of deformation, so as to ensure that the rolling part can be in close contact with the protective film 30 and discharge the air between the protective film 30 and the coating surface 11 of the battery cell 10.

[0076] Along the axial direction of the shaft core 21, the rolling portion includes at least three sections 22 arranged, that is, the number of sections 22 is greater than or equal to three. The shapes of the outer circumferences of these sections 22 include arc-shaped convex surfaces 23, arc-shaped concave surfaces 24 and cylindrical surfaces 25, and the shapes of the outer circumferences of two adjacent sections 22 are different to accommodate the requirements of different flatness of multiple battery cells 10. In this way, the arc-shaped convex surface 23, the arc-shaped concave surface 24 and the cylindrical surface 25 can be used to flatten the protective film 30 and the recessed area 12 / raised area 13 of the battery cell 10, discharge the air between the protective film 30 and the battery cell 10, and improve the film reliability and film yield.

[0077] See also Figures 4 to 7, along the axial direction of the shaft core 21, the middle of the arcuate convex surface 23 protrudes in a direction away from the shaft core 21 relative to the two ends of the arcuate convex surface 23. Figure 7 As shown, along the axial direction of the shaft core 21, the distance between the arcuate convex surface 23 and the axis (shown in OO) of the shaft core 21 increases first and then decreases. The intersection line of the plane containing the axis of the shaft core 21 and the arcuate convex surface 23 is an outward convex arc line, that is, the intersection line is an outer circular arc.

[0078] The height of the highest point of the arc-shaped convex surface 23 is the maximum value of the concave depths of the concave areas 12 of the coating surfaces 11 of the multiple battery cells 10. In this way, the height of the arc-shaped convex surface 23 is greater than or equal to the concave depth of the concave area 12 of the coating surface 11 of each battery cell 10, so that the arc-shaped convex surface 23 and the concave area 12 are adapted to each other along the radial direction of the shaft core 21.

[0079] See also Figures 8 to 11 , along the axial direction of the shaft core 21, the middle of the arc-shaped concave surface 24 is concave relative to the two ends of the arc-shaped concave surface 24 in a direction away from the shaft core 21. Fig.11 As shown, along the axial direction of the shaft core 21, the distance between the arcuate concave surface 24 and the axis (shown in OO) of the shaft core 21 increases first and then decreases. The intersection line of the plane containing the axis of the shaft core 21 and the arcuate concave surface 24 is an inwardly concave arc line, that is, the intersection line is an inner arc.

[0080] The depth of the lowest point of the arc-shaped concave surface 24 is the maximum value of the convex heights of the convex regions 13 of the coating surfaces 11 of the multiple battery cells 10. In this way, the depth of the arc-shaped concave surface 24 is greater than or equal to the convex height of the convex region 13 of the coating surface 11 of each battery cell 10, so that the arc-shaped concave surface 24 and the convex region 13 are adapted to each other along the radial direction of the shaft core 21.

[0081] See also Figures 12 to 15 The cylindrical surface 25 is a cylindrical surface, and along the axial direction of the shaft core 21, the distance between the cylindrical surface 25 and the axis (shown in OO) of the shaft core 21 is equal. The intersection line of the plane containing the axis of the shaft core 21 and the arc-shaped concave surface 24 is a straight line.

[0082] In some possible examples, the ends of two adjacent sections 22 adjacent to each other are transitioned in an arc shape. In this way, along the circumference of the shaft core 21, the outer circumferences of the two adjacent sections 22 are connected in an arc shape, which reduces the damage of the protective film 30 by the rolling part, and also enables the entire outer circumference of the rolling part to cooperate with the coating surface 11 of the battery cell 10.

[0083] In some possible examples, the number of the sections 22 is an integer multiple of 3; along the circumference of the shaft core 21, the shapes of the outer peripheral surfaces of all the sections 22 are arranged cyclically, and are sequentially arcuate convex surfaces 23, arcuate concave surfaces 24, and cylindrical surfaces 25, or sequentially arcuate convex surfaces 23, cylindrical surfaces 25, and arcuate concave surfaces 24. For example, the number of the sections 22 is 3, 6, 9, etc., so that the number of arcuate convex surfaces 23, arcuate concave surfaces 24, and cylindrical surfaces 25 can be equal.

[0084] These subdivisions 22 are arranged in sequence along the circumference of the shaft core 21, and are connected end to end, that is, the rolling portion is an integer multiple of 3 subdivisions 22. And along the circumference of the shaft core 21, the outer circumferences of all subdivisions 22 are arranged in a cycle according to the arc-shaped convex surface 23, the arc-shaped concave surface 24 and the cylindrical surface 25, or in a cycle according to the arc-shaped convex surface 23, the cylindrical surface 25 and the arc-shaped concave surface 24, so as to improve the uniformity of the rolling portion and improve the rolling effect. For example, there are 6 subdivisions 22, and the outer circumferences of these subdivisions 22 are arc-shaped convex surface 23, arc-shaped concave surface 24, cylindrical surface 25, arc-shaped convex surface 23, arc-shaped concave surface 24, and cylindrical surface 25 in sequence.

[0085] In some possible examples, the rolling portion is divided into a plurality of sub-sections, that is, along the circumference of the shaft core 21, the center angle θ corresponding to each sub-section 22 is equal. The product of the center angle corresponding to each sub-section 22 and the number of sub-sections 22 is 360°. For example, there are 3 sub-sections 22, and the center angle corresponding to each sub-section 22 is 120°. For another example, there are 9 sub-sections 22, and the center angle corresponding to each sub-section 22 is 40°.

[0086] The chord length corresponding to the central angle of each section 22 is the minimum value of the average value of the width of the convex area 13 and the average value of the width of the concave area 12 of the coating surface 11 of the multiple battery cells 10. The chord length corresponding to the central angle of each section 22 refers to: the distance between the starting edge (S1) and the ending edge (S2) of the section 22 along the circumference of the axial core 21, such as Fig.16 The Z shown in FIG. The central angle can be calculated from the chord length, thereby determining the number of sections 22 .

[0087] Along the axial direction of the shaft core 21, the lengths of the sub-sections 22 are the same, so that the two ends of the sub-sections 22 can be aligned, so that the two opposite ends of the rolling portion are both planes. Along the axial direction of the shaft core 21, the two opposite ends of the rolling portion are annular or elliptical. In this way, the two ends of the multiple sub-sections 22 are smoothly transitioned along the circumference of the shaft core 21, and the multiple sub-sections 22 can form a relatively neat integrated structure.

[0088] The compression amount of the rolling part is the average value of the depression depths of the depression areas 12 of the plurality of battery cells 10 or the average value of the protrusion heights of the protrusion areas 13 of the plurality of battery cells 10. The hardness of the silicone material is determined according to the compression amount of the rolling part, that is, the greater the compression amount of the rolling part, the greater the hardness of the silicone material.

[0089] The roller 20 in the embodiment of the present application is used to coat multiple battery cells 10, and the roller 20 includes an axial core portion 21 and a rolling portion, and the rolling portion is sleeved on the axial core portion 21. The rolling portion includes at least three sections 22 arranged along the circumference of the axial core portion 21, and the shapes of the outer peripheral surfaces of the at least three sections 22 include an arcuate convex surface 23, an arcuate concave surface 24 and a cylindrical surface 25, and the shapes of the outer peripheral surfaces of two adjacent sections 22 are different. Among them, along the axial direction of the axial core portion 21, the middle part of the arcuate convex surface 23 is convex relative to the two ends of the arcuate convex surface 23 in the direction away from the axial core portion 21, and the middle part of the arcuate concave surface 24 is concave relative to the two ends of the arcuate concave surface 24 in the direction close to the axial core portion 21. The rolling portion includes multiple sections 22 with different outer peripheral shapes, which can be compatible with the requirements of different flatness of multiple battery cells 10. The arc-shaped convex surface 23 , the arc-shaped concave surface 24 and the cylindrical surface 25 are used to flatten the protective film 30 and the recessed area 12 / raised area 13 of the battery cell 10 , and the air between the protective film 30 and the battery cell 10 is discharged, thereby improving the reliability and yield of the encapsulation.

[0090] The present application also provides a coating method, see Fig.17 , the coating method specifically comprises the following steps:

[0091] Step S100: a detection device detects the flatness of coating surfaces of a plurality of battery cells to be coated, and obtains flatness data of the coating surfaces.

[0092] See also Fig.18 and Figure 3 The detection device includes, for example, a 3D camera, and specifically uses a 3D line scan camera to detect the flatness of the coating surface 11 of the battery cell 10 to obtain (for example, form by fitting) flatness data. The flatness data can reflect the degree of concavity and convexity of the coating surface 11 of the battery cell 10 to be coated.

[0093] Specifically, the concave degree of the coating surface 11 of the battery cell 10 includes the concave depth, width and gradient of the concave area 12. The concave depth of the concave area 12 represents the concave degree of the concave area 12, which is the concave depth of the concave area 12 along the thickness direction of the battery cell 10 ( Figure 3 The dimensions of the Z direction are as shown in Figure 3 The width of the concave region 12 represents the distribution range of the concave region 12, which is the width of the concave region 12 along the moving direction of the battery cell 10 ( Figure 3 and Fig.18 The dimensions of the X direction are shown as Figure 3The gradient of the concave region 12 represents the slope of the concave region 12, that is, whether the change is rapid or slow.

[0094] The convexity of the coating surface 11 of the battery cell 10 includes the convexity height, width and gradient of the convex area 13. The convexity height of the convex area 13 represents the convexity of the convex area 13, which is the size of the convex area 13 along the thickness direction of the battery cell 10, such as Figure 3 The width of the raised area 13 represents the distribution range of the raised area 13, which is the size of the raised area 13 along the moving direction of the battery cell 10, as shown in FIG. Figure 3 The gradient of the raised area 13 represents the slope of the raised area 13 , that is, the change is rapid or slow. The gradient of the raised area 13 and the gradient of the recessed area 12 form the flatness gradient of the coating surface 11 of the battery cell 10 .

[0095] Step S200: forming a roller according to the flatness data, the roller comprising an axial core portion, and a rolling portion sleeved on the axial core portion; the rolling portion comprising at least three sections arranged along the circumference of the axial core portion, the shapes of the outer peripheral surfaces of the at least three sections comprising an arcuate convex surface, an arcuate concave surface and a cylindrical surface, and the shapes of the outer peripheral surfaces of two adjacent sections are different; wherein, along the axial direction of the axial core portion, the middle portion of the arcuate convex surface protrudes in a direction away from the axial core portion relative to the two ends of the arcuate convex surface, and the middle portion of the arcuate concave surface is recessed in a direction close to the axial core portion relative to the two ends of the arcuate concave surface.

[0096] See also Figures 4 to 16 According to the flatness data, a roller 20 is manufactured. The roller 20 includes a shaft core 21 and a rolling part. The rolling part is sleeved on the shaft core 21. The shaft core 21 can be cylindrical. The axial direction of the shaft core 21 is as follows: Figure 7 , Fig.11 , Fig.15 The M direction shown in FIG. 1 and the circumferential direction of the shaft core 21 are as shown in FIG. Figure 4 , Figure 8 , Fig.12 The material of the shaft core 21 can be metal, so that the roller 20 has a certain hardness and can provide pressure to the battery cell 10 and the protective film 30.

[0097] The rolling part is sleeved outside the shaft core 21, and the rolling part and the shaft core 21 are relatively fixed, for example, the two are interference fit. Along the axial direction of the shaft core 21, both ends of the shaft core 21 extend outward from the rolling part, so that the shaft core 21 is connected to an external drive mechanism to drive the shaft core 21 to rotate. The material of the rolling part includes silicone material, so that the rolling part is soft and has a certain amount of deformation, so as to ensure that the rolling part can be in close contact with the protective film 30 and discharge the air between the protective film 30 and the coating surface 11 of the battery cell 10.

[0098] Along the axial direction of the shaft core 21, the rolling portion includes at least three sections 22 arranged, that is, the number of sections 22 is greater than or equal to three. The shapes of the outer circumferences of these sections 22 include arcuate convex surfaces 23, arcuate concave surfaces 24 and cylindrical surfaces 25, and the shapes of the outer circumferences of two adjacent sections 22 are different, so that the roller 20 has multiple different outer surfaces to accommodate the requirements of different flatness of multiple battery cells 10. In this way, the arcuate convex surface 23, the arcuate concave surface 24 and the cylindrical surface 25 can be used to flatten the protective film 30 and the recessed area 12 / raised area 13 of the battery cell 10, discharge the air between the protective film 30 and the battery cell 10, and improve the film reliability and film yield.

[0099] See also Figures 4 to 7 , along the axial direction of the shaft core 21, the middle of the arcuate convex surface 23 protrudes in a direction away from the shaft core 21 relative to the two ends of the arcuate convex surface 23. Figure 7 As shown, along the axial direction of the shaft core 21, the distance between the arcuate convex surface 23 and the axis (shown in OO) of the shaft core 21 increases first and then decreases. The intersection line of the plane containing the axis of the shaft core 21 and the arcuate convex surface 23 is an outward convex arc line, that is, the intersection line is an outer circular arc.

[0100] The height of the highest point of the arc-shaped convex surface 23 is the maximum value of the concave depths of the concave areas 12 of the coating surfaces 11 of the multiple battery cells 10. In this way, the height of the arc-shaped convex surface 23 is greater than or equal to the concave depth of the concave area 12 of the coating surface 11 of each battery cell 10, so that the arc-shaped convex surface 23 and the concave area 12 are adapted to each other along the radial direction of the shaft core 21.

[0101] See also Figures 8 to 11 , along the axial direction of the shaft core 21, the middle of the arc-shaped concave surface 24 is concave relative to the two ends of the arc-shaped concave surface 24 in a direction away from the shaft core 21. Fig.11 As shown, along the axial direction of the shaft core 21, the distance between the arcuate concave surface 24 and the axis (shown in OO) of the shaft core 21 increases first and then decreases. The intersection line of the plane containing the axis of the shaft core 21 and the arcuate concave surface 24 is an inwardly concave arc line, that is, the intersection line is an inner arc.

[0102] The depth of the lowest point of the arc-shaped concave surface 24 is the maximum value of the convex heights of the convex regions 13 of the coating surfaces 11 of the multiple battery cells 10. In this way, the depth of the arc-shaped concave surface 24 is greater than or equal to the convex height of the convex region 13 of the coating surface 11 of each battery cell 10, so that the arc-shaped concave surface 24 and the convex region 13 are adapted to each other along the radial direction of the shaft core 21.

[0103] See also Figures 12 to 15 The cylindrical surface 25 is a cylindrical surface 25, and along the axial direction of the shaft core 21, the distance between the cylindrical surface 25 and the axis (shown in OO) of the shaft core 21 is equal. The intersection line of the plane containing the axis of the shaft core 21 and the arc-shaped concave surface 24 is a straight line.

[0104] The compression amount of the rolling part is the average value of the depression depths of the depression areas 12 of the plurality of battery cells 10 or the average value of the protrusion heights of the protrusion areas 13 of the plurality of battery cells 10. The hardness of the silicone material is determined according to the compression amount of the rolling part, that is, the greater the compression amount of the rolling part, the greater the hardness of the silicone material.

[0105] In some possible examples, the rolling portion is divided into a plurality of sub-portions 22, that is, along the circumference of the shaft core portion 21, the center angle θ corresponding to each sub-portion 22 is equal. The product of the center angle corresponding to each sub-portion 22 and the number of sub-portions 22 is 360°. For example, there are 3 sub-portions 22, and the center angle corresponding to each sub-portion 22 is 120°. For another example, there are 9 sub-portions 22, and the center angle corresponding to each sub-portion 22 is 40°.

[0106] The chord length corresponding to the central angle of each section 22 is the minimum value of the average value of the width of the convex area 13 and the average value of the width of the concave area 12 of the coating surface 11 of the multiple battery cells 10. The chord length corresponding to the central angle of each section 22 refers to: the distance between the starting edge (S1) and the ending edge (S2) of the section 22 along the circumference of the axial core 21, such as Fig.16 As shown in Z.

[0107] The average value of the widths of the raised areas 13 of the coating surfaces 11 of the plurality of battery cells 10 is taken as the average width Y1 of the raised areas 13. 均 The average value of the width of the concave region 12 of the coating surface 11 of the plurality of battery cells 10 is taken as the average width Y2 of the concave region 12. 均 Take the average width Y1 of the raised area 13 均 and the average width Y2 of the recessed area 12 均 The minimum value of the chord length is min(Y1 均 , Y2 均 )=Z, according to which the center angle of the circle can be determined, thereby determining the number of the divisions 22.

[0108] In this way, the average width Y1 of the raised area 13 of the coating surface 11 of the plurality of battery cells 10 is 均 and the average width Y2 of the recessed area 12 均The minimum value in is used as the basis for the roller 20 to divide evenly, so that the outer peripheral surface of the formed section 22 can ensure the contact with the raised area 13 / recessed area 12 of the coating surface 11 to the greatest extent, and the outer peripheral surfaces of different sections 22 and the raised areas 13 / recessed areas 12 of the coating surfaces 11 of multiple battery cells 10 have good adaptability. Among them, the section 22 with the arc-shaped concave surface 24 is used to cooperate with the raised area 13 of the coating surface 11 of the battery cell 10, ensuring that the protective film 30 can be well coated on the raised area 13 of the coating surface 11 of the battery cell 10. The section 22 with the arc-shaped convex surface 23 is used to cooperate with the recessed area 12 of the coating surface 11 of the battery cell 10, ensuring that the protective film 30 can be well coated on the recessed area 12 of the coating surface 11 of the battery cell 10.

[0109] In some possible examples, the number of the sections 22 is an integer multiple of 3; along the circumference of the shaft core 21, the shapes of the outer peripheral surfaces of all the sections 22 are arranged cyclically, and are sequentially arcuate convex surfaces 23, arcuate concave surfaces 24, and cylindrical surfaces 25, or sequentially arcuate convex surfaces 23, cylindrical surfaces 25, and arcuate concave surfaces 24. For example, the number of the sections 22 is 3, 6, 9, etc., so that the number of arcuate convex surfaces 23, arcuate concave surfaces 24, and cylindrical surfaces 25 can be equal.

[0110] These subdivisions 22 are arranged in sequence along the circumference of the shaft core 21, and are connected end to end, that is, the rolling portion is an integer multiple of 3 subdivisions 22. And along the circumference of the shaft core 21, the outer circumferences of all subdivisions 22 are arranged in a cycle according to the arc-shaped convex surface 23, the arc-shaped concave surface 24 and the cylindrical surface 25, or in a cycle according to the arc-shaped convex surface 23, the cylindrical surface 25 and the arc-shaped concave surface 24, so as to improve the uniformity of the rolling portion and improve the rolling effect. For example, there are 6 subdivisions 22, and the outer circumferences of these subdivisions 22 are arc-shaped convex surface 23, arc-shaped concave surface 24, cylindrical surface 25, arc-shaped convex surface 23, arc-shaped concave surface 24, and cylindrical surface 25 in sequence.

[0111] Step S300: The conveying mechanism conveys the battery cell to contact the protective film, and uses rollers to press the protective film onto the battery cell.

[0112] See also Fig.18 The conveying mechanism conveys the battery cell 10 to the coating station, so that the battery cell 10 and the protective film 30 are in contact, and also drives the battery cell 10 and the protective film 30 to pass through the area where the roller 20 is located. The rollers 20 are arranged on both sides of the large surface of the battery cell 10, that is, the rollers 20 include an upper roller and a lower roller, and the battery cell 10 and the protective film 30 pass between the upper roller and the lower roller. The upper roller coats the coating surface 11 at the top of the battery cell 10, and the lower roller coats the coating surface 11 at the bottom of the battery cell 10.

[0113] One end of the roller 20 is connected to a driving mechanism, such as a servo motor, and the other end of the roller 20 is connected to a rotating shaft. After receiving a start signal, the driving mechanism drives the roller 20 to rotate, so that the roller 20 reciprocates and rolls the protective film 30 with different contours to adapt to the flatness of different battery cells 10, so that the battery cells 10 are coated. After the coating is completed, the roller 20 stops rotating. The driving mechanism controls the speed of the roller 20.

[0114] The speed of the roller 20 can be adjusted, specifically in real time according to the flatness gradient. The greater the flatness gradient, the greater the speed of the roller 20. In this way, the roller 20 can be adaptively adjusted according to the flatness of the battery cell 10, so as to adapt to the coating surface 11 of various battery cells 10, ensure that the roller 20 can flatten the protective film 30 and the recessed area 12 and the protruding area of ​​the battery cell 10, achieve adaptive compatibility of various battery cells 10, and ensure the coating effect.

[0115] Specifically, the moving speed of the battery cell 10 is E (mm / s), the rotation speed of the roller 20 is F (rpm / s), the number of revolutions of the roller 20 per unit length along the moving direction of the battery cell 10 is G, F=G / (1 / E), G≥1, so that the entire outer circumference of the roller 20 is in contact with the protective film 30 per unit length of the battery cell 10. The G value determines the number of times the different outer shapes of the roller 20 contact the protective film 30, thereby determining the flatness range of the entire outer circumference of the roller 20 to adapt to the battery cell 10. According to the flatness gradient of different battery cells 10 tested on site, the relationship between the flatness gradient of the battery cell 10 and the rotation speed F of the roller 20 is calculated to form a corresponding relationship list.

[0116] In the example where the roller 20 includes an upper roller and a lower roller, the rotation speeds of the upper roller and the lower roller can be adjusted respectively, which are adapted to the flatness of the corresponding coating surface 11. In some possible implementations, the coating method further includes: a detection device detecting the coating effect of the battery cell 10, and optimizing the relationship between the rotation speed of the roller 20 and the flatness gradient, so as to further improve the adaptive compatibility of the roller 20 with the battery cell 10.

[0117] See also Fig.18 and Fig.19 The coating method specifically includes the following processes:

[0118] The battery cell 10 is put on the production line and transferred to the inspection station;

[0119] Using a 3D camera to detect the flatness of the coating surface 11 of the battery cell 10 to obtain flatness data;

[0120] The inspected battery cells 10 are loaded by a conveying mechanism, and the battery cells 10 are positioned;

[0121] The clamp grasps and takes the positioned battery cell 10 and transfers it to the coating station at a set speed;

[0122] The bottom of the battery cell 10 contacts the protective film 30 , and according to the flatness data of the coating surface 11 of the battery cell 10 , the roller 20 dynamically adjusts the rotation speed in real time to press the protective film 30 in a direction perpendicular to the coating surface 11 of the battery cell 10 (from top to bottom);

[0123] The battery cell 10 continues to move forward, and according to the flatness data of the coating surface 11 of the battery cell 10, the roller 20 dynamically adjusts the rotation speed in real time, and presses the protective film 30 along the moving direction relative to the battery cell 10 (from front to back), and the protective film 30 is cut at the same time;

[0124] After the coating is completed, the battery cell 10 is transferred to the inspection station, and the coating effect is inspected using a 3D camera;

[0125] According to the envelope detection results, the relationship between the rotation speed and the flatness gradient is re-optimized.

[0126] In the coating method in the embodiment of the present application, the flatness of the coating surface 11 of the plurality of battery cells 10 to be coated is detected by a detection device, the flatness data of the coating surface 11 is obtained, and the roller 20 is formed by using the flatness data, and the protective film 30 is coated on the battery cell 10 by using the roller 20. The roller 20 includes an axial core 21, and a rolling portion sleeved on the axial core 21; the rolling portion includes at least three sections 22 arranged along the circumference of the axial core 21, and the shapes of the outer peripheral surfaces of the at least three sections 22 include an arcuate convex surface 23, an arcuate concave surface 24 and a cylindrical surface 25, and the shapes of the outer peripheral surfaces of two adjacent sections 22 are different; wherein, along the axial direction of the axial core 21, the middle part of the arcuate convex surface 23 is convex relative to the two ends of the arcuate convex surface 23 in a direction away from the axial core 21, and the middle part of the arcuate concave surface 24 is concave relative to the two ends of the arcuate concave surface 24 in a direction close to the axial core 21. The rolling part includes a plurality of sections 22 with different peripheral shapes, which can accommodate the requirements of different flatness of multiple battery cells 10. The arc-shaped convex surface 23, the arc-shaped concave surface 24 and the cylindrical surface 25 are used to flatten the protective film 30 and the recessed area 12 / convex area 13 of the battery cell 10, and the air between the protective film 30 and the battery cell 10 is discharged, thereby improving the film coating reliability and film coating yield.

[0127] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A roller, characterized in that: Used for coating a plurality of battery cells (10), the roller (20) comprising: an axis core portion (21), and a rolling portion sleeved on the axis core portion (21); The rolling portion comprises at least three sections (22) arranged along the circumferential direction of the shaft core portion (21); the shapes of the outer peripheral surfaces of the at least three sections (22) comprise an arcuate convex surface (23), an arcuate concave surface (24) and a cylindrical surface (25); and the shapes of the outer peripheral surfaces of two adjacent sections (22) are different; Wherein, along the axial direction of the shaft core portion (21), the middle portion of the arcuate convex surface (23) is convex in a direction away from the shaft core portion (21) relative to the two ends of the arcuate convex surface (23), and the middle portion of the arcuate concave surface (24) is concave in a direction close to the shaft core portion (21) relative to the two ends of the arcuate concave surface (24).

2. The roller according to claim 1, characterized in that: One end of two adjacent subsections (22) adjacent to each other is in an arc transition.

3. The roller according to claim 1, characterized in that: The material of the rolling part includes silicone material.

4. The roller according to claim 1, characterized in that: Along the axial direction of the shaft core (21), the two opposite ends of the rolling portion are in the shape of a circular ring or an elliptical ring.

5. The roller according to any one of claims 1 to 4, characterized in that: The number of the subsections (22) is an integer multiple of 3; Along the circumference of the shaft core (21), the shapes of the outer peripheral surfaces of all the subsections (22) are arranged in a cyclic manner, and are, in sequence, an arc-shaped convex surface (23), an arc-shaped concave surface (24), and a cylindrical surface (25), or are, in sequence, an arc-shaped convex surface (23), a cylindrical surface (25), and an arc-shaped concave surface (24).

6. The roller according to any one of claims 1 to 4, characterized in that: The rolling section is divided into a plurality of subsections (22).

7. The roller according to claim 6, characterized in that: The chord length corresponding to the central angle of each of the subsections (22) is the minimum value of the average value of the width of the convex region (13) and the average value of the width of the concave region (12) of the coating surface (11) of the plurality of battery cells (10).

8. The roller according to any one of claims 1 to 4, characterized in that: The depth of the lowest point of the arc-shaped concave surface (24) is the maximum value among the convex heights of the convex areas (13) of the coating surfaces (11) of the plurality of battery cells (10).

9. The roller according to any one of claims 1 to 4, characterized in that: The height of the highest point of the arc-shaped convex surface (23) is the maximum value among the depression depths of the depression areas (12) of the coating surfaces (11) of the plurality of battery cells (10).

10. The roller according to any one of claims 1 to 4, characterized in that: The compression amount of the rolling part is an average value of the depression depths of the depression areas (12) of the plurality of battery cells (10), or an average value of the protrusion heights of the protrusion areas (13) of the plurality of battery cells (10).

11. The roller according to any one of claims 1 to 4, characterized in that: Along the axial direction of the shaft core (21), the lengths of the subsections (22) are the same.

12. A coating device, characterized in that: include: A conveying mechanism, a roller (20) according to any one of claims 1 to 10, and a driving mechanism; The conveying mechanism is used to convey the battery core (10), and the driving mechanism is in transmission connection with the roller (20) to drive the roller (20) to rotate.

13. A coating method, characterized in that: include: The detection device detects the flatness of the coating surface (11) of the plurality of battery cells (10) to be coated, and obtains the flatness data of the coating surface (11); A roller (20) is formed according to the flatness data, the roller (20) comprising: an axial core portion (21), and a rolling portion sleeved on the axial core portion (21); the rolling portion comprises at least three sub-portions (22) arranged along the circumference of the axial core portion (21); the shapes of the outer peripheral surfaces of the at least three sub-portions (22) comprise an arcuate convex surface (23), an arcuate concave surface (24) and a cylindrical surface (25), and the shapes of the outer peripheral surfaces of two adjacent sub-portions (22) are different; wherein, along the axial direction of the axial core portion (21), the middle portion of the arcuate convex surface (23) is convex in a direction away from the axial core portion (21) relative to the two ends of the arcuate convex surface (23), and the middle portion of the arcuate concave surface (24) is concave in a direction close to the axial core portion (21) relative to the two ends of the arcuate concave surface (24); The conveying mechanism conveys the battery core (10) to contact the protective film (30), and utilizes the roller (20) to press the protective film (30) onto the battery core (10).

14. The coating method according to claim 13, characterized in that: The flatness data includes a flatness gradient, and when the protective film (30) is pressed onto the battery core (10), the rotation speed of the roller (20) is adjusted in real time according to the flatness gradient.

15. The coating method according to claim 14, characterized in that: Also includes: The detection device detects the coating effect of the battery core (10) and optimizes the relationship between the rotation speed of the roller (20) and the flatness gradient.

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