Rolling device, battery production system, and stretching roller manufacturing apparatus

Abstract

The embodiment of the present application provides a kind of roller pressing device, battery production system and stretching roller manufacturing equipment, roller pressing device includes at least one pair of rolls and stretching roller, at least one pair of rolls is used to extrude the opposite sides of diaphragm, stretching roller is set to the upstream or downstream of a pair of rolls, stretching roller includes roller body and convex part, roller body includes tape area, tape area is used to contact the film area of diaphragm, tape area is provided with convex part along the at least one side of the axial direction of roller body, and convex part is set to the outside of tape area, convex part is set around the circumferential direction of roller body and protrudes the outer surface of roller body, convex part is used to contact and stretch the margin area of diaphragm, wherein, convex part is printed and formed on roller body.The present application can improve the stretching effect of the margin area of diaphragm.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a rolling device, a battery production system, and a stretching roll manufacturing equipment. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery technology, films coated with active material are used to form the electrodes of battery cells, and the blank areas of the films are used to form the tabs of the electrodes. How to improve the stretching effect of the blank areas of the films is a research direction in battery technology. Utility Model Content

[0004] This application provides a roller pressing device, a battery production system, and a stretching roller manufacturing equipment, which can improve the stretching effect of the blank area of ​​the film.

[0005] This application provides a roll forming device, which includes at least one pair of rollers and a stretching roller. The at least one pair of rollers is used to extrude the opposite sides of a film. The stretching roller is disposed upstream or downstream of the pair of rollers. The stretching roller includes a roller body and a protrusion. The roller body includes a conveying area for contacting the film area of ​​the film. The protrusion is provided on at least one side of the conveying area along the axial direction of the roller body, and the protrusion is disposed on the outside of the conveying area. The protrusion surrounds the circumference of the roller body and protrudes from the outer surface of the roller body. The protrusion is used to contact and stretch the blank area of ​​the film. The protrusion is printed and formed on the roller body.

[0006] In the above technical solution, the stretching principle of this application is to provide a protrusion on at least one side of the roller body along the axial direction of the conveyor belt area. During the conveyor belt transport process, the protrusion can stretch the blank area. By printing the protrusion onto the roller body, the formed protrusion has higher manufacturing precision and richer shape compared to Teflon / rubber tape. Therefore, the required shape and thickness can be obtained so that the blank area achieves the required stretching effect.

[0007] In some embodiments, the outer surface of the roller body and the protrusions are made of different materials.

[0008] In the above technical solution, by using different materials for the protrusion and the roller body, the bonding force between the two is weaker compared to using the same material, thus making it easier to remove the protrusion during shape change. Furthermore, it increases the freedom in selecting materials for the protrusion.

[0009] In some embodiments, the protrusion is a UV-curable inkjet component.

[0010] In the above technical solution, UV curing inkjet printing relies on ink self-leveling, so the surface of the UV curing inkjet part formed after curing is smooth, and the edges and corners are smoothly transitioned. No post-processing is required, the damage to the blank area is small, and the wear resistance and durability are also excellent. It reduces the problem of tape breakage caused by stress concentration and excessive stretching at the edge of the tower-shaped Teflon.

[0011] In some embodiments, the protrusion includes a transition portion and a stretching portion. The transition portion is attached to the roller body, and the stretching portion is located on the side of the transition portion away from the roller body and is used for the blank area of ​​the stretching film. The projection of the stretching portion on the transition portion along the radial direction of the roller body is located inside the transition portion.

[0012] In the above technical solution, if the stretching sub-section has a protruding portion along the axial direction of the roller body relative to the transition sub-section, the protruding portion will be damaged due to lack of support during continuous stress. Therefore, by setting the projection of the stretching sub-section along the radial direction of the roller body onto the transition sub-section within the transition sub-section, the durability of the protrusion can be improved.

[0013] In some embodiments, the stretching sub-section includes a convex surface disposed away from the transition sub-section. The convex surface bulges outward from the transition sub-section in the central region of the roller body in the axial direction. The convex surface is used as a blank area for stretching the film.

[0014] In the above technical solution, the blank area of ​​the stretching diaphragm is compressed using a convex curved surface. The convex curved surface can adapt to the stress conditions at the root and top of the tab. The top of the tab requires a larger amount of extension to reduce the stress of bending and warping, so the convex curved surface can better adapt. Furthermore, because the convex curved surface has a smooth bend, it can reduce the stress concentration area in the blank area, making it less prone to strip breakage, and is more suitable for situations where a larger amount of extension is required in the blank area.

[0015] In some embodiments, the stretching sub-section includes a stretching surface and two connecting surfaces. The stretching surface is disposed opposite to the transition sub-section, and each part of the stretching surface is equidistant from the roller body. The stretching surface is used to stretch the blank area of ​​the film. The two connecting surfaces are respectively disposed on opposite sides of the stretching surface along the axial direction of the roller body. One end of the connecting surface is connected to the stretching surface, and the other end is connected to the transition sub-section.

[0016] In the above technical solution, each part of the stretching surface is set to be equidistant from the roller body, which reduces the printing difficulty and facilitates processing.

[0017] In some embodiments, the distance between the two connecting surfaces gradually decreases along the direction from the transition sub-part to the stretching sub-part.

[0018] The above technical solution provides better support for the stretched surface, thus improving its service life. Furthermore, it allows the tensile force on the blank area to transition smoothly at the connection surface, reducing stress concentration areas in the blank area.

[0019] In some embodiments, along the direction from the transition sub-part to the stretching sub-part, both connecting surfaces are inclined toward each other, and the cross-sectional shape of the connecting surfaces in their own circumferential direction is a straight line.

[0020] The above technical solution ensures that all parts of the stretched surface are well supported, thus improving service life. Furthermore, it allows for a smooth transition of pressure on the blank area between the two connecting surfaces, further reducing stress concentration areas in the blank area.

[0021] In some embodiments, the transition section protrudes axially along the roller body and is disposed at opposite ends of the stretching section.

[0022] In the above technical solution, the top of the tab needs a larger extension to reduce the stress of bending and warping. The transition part is set to protrude along the axial direction of the roller body at the opposite ends of the stretching part. Then the stretching part corresponds to the non-root area of ​​the tab. After stretching, the stress of the tab can be reduced, especially the stress in the area near the top of the tab, and the tab folding can be improved.

[0023] In some embodiments, the transition sub-part includes a first surface and a second surface arranged radially opposite to each other along the roller body. The first surface is in contact with the roller body, and there are two second surfaces. The two second surfaces protrude from both ends of the stretching sub-part along the axial direction of the roller body, respectively. The first surface and the second surface are arranged in parallel, and the two second surfaces are coplanar.

[0024] In the above technical solution, setting the two second surfaces as coplanar ensures that the forces exerted by the transition sub-parts on the blank area at both ends along the axial direction of the roller body are the same, improving the symmetry on both sides and making it suitable for the scenario of a blank area located between two film areas.

[0025] In some embodiments, there are multiple belt-carrying areas and multiple protrusions, which are alternately arranged along the axial direction of the roller body.

[0026] The above technical solution can stretch more blank areas at the same time to suit a variety of usage scenarios.

[0027] In some embodiments, the stretching roller is a tension floating roller.

[0028] In the above technical solution, the stretching roller is set as a tension floating roller, so that the tension of the stretching roller on the film is approximately constant and always kept at a high tension, which can better stretch the blank area, improve the stretching effect, and reduce the possibility of tape breakage.

[0029] Secondly, embodiments of this application also provide a battery production system, including the aforementioned rolling device.

[0030] Thirdly, embodiments of this application also provide a stretch roll manufacturing apparatus, including a support device, a printing device, and a driving device. The support device supports a roll body, the roll body including a belt-carrying area. The printing device prints a protrusion on at least one side of the belt-carrying area along the axial direction of the roll body, such that the protrusion protrudes beyond the outer surface of the roll body and is disposed outside the belt-carrying area. The driving device drives the roll body to rotate, so that the protrusion is formed circumferentially around the roll body. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of the roller pressing device provided in some embodiments of this application;

[0033] Figure 2 This is a schematic diagram of the structure of the stretching roller in the roller pressing device provided in some embodiments of this application;

[0034] Figure 3 A schematic diagram of the structure of the protrusion of the stretching roller in some embodiments of the present application;

[0035] Figure 4 This is a schematic diagram of another structure of the protrusion of the stretching roller in some embodiments of the rolling device provided in this application;

[0036] Figure 5 This is a schematic diagram of the structure of a stretching roll manufacturing apparatus provided in some embodiments of this application.

[0037] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0038] 100. Roller pressing device; 110. Unwinding mechanism; 120. Rewinding mechanism; 200. Support device; 300. Printing device; 400. Drive device;

[0039] 1. Rolls;

[0040] 2. Stretching roller; 21. Roller body; 211. Belt carrying area; 22. Protrusion; 221. Transition sub-section; 222. Stretching sub-section; 223. Outwardly convex curved surface; 224. Stretching surface; 225. Connecting surface; 226. First surface; 227. Second surface;

[0041] 3. Membrane sheet; 31. Membrane area; 32. Blank area. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0044] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0046] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0047] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0048] In this application, "multiple" means two or more (including two).

[0049] In the production process of battery cells, processes such as coating, drying and rolling are required. The coating process involves applying a slurry to the substrate to form a film area, and the rolling process involves compacting the film area to make it thinner and denser, thereby improving the energy density of the electrode and improving its conductivity.

[0050] In the rolling process, the blank area adjacent to the film area also needs to be stretched to improve the abnormalities such as wrinkling, shrinkage or even breakage of the blank area due to excessive stress caused by not being stretched, which would affect the processing of the electrode sheet.

[0051] One method involves attaching Teflon / tape to the roller at the position corresponding to the blank area to form a stepped structure, which stretches the blank area. However, Teflon / tape has limited thickness and shape, often being applied in a tower shape, making it difficult to achieve the desired shape and thickness.

[0052] In view of this, this application provides a roll pressing device, which provides a stretching roller upstream or downstream of the roll, and provides a protrusion on at least one side of the belt carrying area. The protrusion is arranged circumferentially around the roll body, and the protrusion is printed on the roll body. In this way, the printed protrusion is manufactured with high precision and the step shape is enriched. Therefore, the desired shape and thickness of the protrusion can be obtained so that the blank area can achieve the desired stretching effect as required.

[0053] The technical solutions described in the embodiments of this application are applicable to the rolling process of diaphragms, wherein the diaphragms are used to form the electrodes of a battery cell.

[0054] Figure 1 This is a schematic diagram of the structure of the roller pressing device provided in some embodiments of this application. Figure 2 This is a schematic diagram of the structure of the stretching roller in the roller pressing device provided in some embodiments of this application.

[0055] like Figure 1 and Figure 2 As shown, this application also provides a roll forming apparatus 100, including at least a pair of rollers 1 and a stretching roller 2. The at least one pair of rollers 1 is used to extrude the opposite sides of the film 3. The stretching roller 2 is disposed upstream or downstream of the pair of rollers 1. The stretching roller 2 includes a roller body 21 and a protrusion 22. The roller body 21 includes a conveying area 211 for contacting the film area 31 of the film 3. The conveying area 211 has a protrusion 22 disposed on at least one side along the axial direction X of the roller body 21, and the protrusion 22 is disposed on the outside of the conveying area 211. The protrusion 22 surrounds the circumference of the roller body 21 and protrudes from the outer surface of the roller body 21. The protrusion 22 is used to contact and stretch the blank area 32 of the film 3, wherein the protrusion 22 is printed on the roller body 21.

[0056] For example, the roll forming device 100 includes an unwinding mechanism 110 and a winding mechanism 120, wherein the unwinding mechanism 110 is used to release the film 3 and the winding mechanism 120 is used to wind back the rolled and stretched film 3.

[0057] In this embodiment, the pair of rollers 1 are two high-strength, high-precision rollers 1 (typically made of cemented carbide steel or composite materials) rotating in opposite directions under a preset pressure. The diaphragm 3 passes through the gap (roll gap) between the two rollers. The gap of the roll gap is smaller than the initial thickness of the diaphragm 3, so when the electrode passes through, it is subjected to a huge linear pressure (pressure per unit roll width, typically in the ton / cm range) applied by the rollers 1, causing the diaphragm 3 to undergo particle rearrangement, plastic deformation, and binder flow as it passes through the gap of the rollers 1, thereby achieving mechanical densification. Exemplarily, the roller pressing device 100 includes a drive mechanism for driving the pair of rollers 1 to rotate in opposite directions.

[0058] In this embodiment, the conveyor belt area 211 is used to contact the membrane area 31 of the diaphragm 3. For example, the conveyor belt area 211 is used to drive the diaphragm 3 to move.

[0059] A protrusion 22 is disposed on the outer side of the conveyor belt area 211 for stretching the blank area 32. The protrusion 22 can be configured to contact the entire blank area 32 to stretch it, or it can contact the portion of the blank area 32 along the axial direction X of the roller body 21 to stretch only that portion. Similarly, the conveyor belt area 211 can be configured to contact the entire film area 31, or it can contact the portion of the film area 31 along the axial direction X of the roller body 21.

[0060] In this embodiment, the shape of the cross-section of the protrusion 22 in the direction surrounding the roller body 21 can be rectangular, trapezoidal, or convex arc-shaped.

[0061] Optionally, the conveyor belt area 211 is provided with protrusions 22 on both opposite sides of the axial direction X of the roller body 21.

[0062] In this embodiment, the protrusion 22 is arranged around the circumference of the roller body 21 and protrudes from the outer surface of the roller body 21. This means that the protrusion 22 is arranged in a circle around the roller body 21, and each part in the circumferential direction protrudes from the outer surface of the roller body 21.

[0063] For example, the roller body 21 and the protrusion 22 are two structural components made of different materials. Furthermore, the roller body 21 is made of a metallic material, such as stainless steel or alloy steel.

[0064] In this embodiment, the protrusion 22 is printed on the roller body 21, meaning that the protrusion 22 is printed onto the roller body 21 using printing technology. For example, the protrusion 22 can be printed onto the roller body 21 using 3D printing (additive manufacturing). 3D printing is a digital manufacturing technology that creates three-dimensional objects by depositing materials layer by layer. Unlike traditional subtractive manufacturing (such as cutting and drilling), 3D printing is computer-controlled to stack materials (such as plastics, metals, ceramics, etc.) layer by layer to ultimately form complex three-dimensional objects.

[0065] The stretching principle of this application involves providing a protrusion 22 on at least one side of the conveyor belt 211 along the axial direction of the roller body 21. During the conveyor belt movement, the protrusion 22 can stretch the blank area 32. By printing the protrusion 22 onto the roller body 21, the formed protrusion 22 has higher manufacturing precision and richer shape compared to Teflon / rubber tape. Therefore, the required shape and thickness can be obtained to achieve the desired stretching effect in the blank area 32.

[0066] In some embodiments, the outer surface of the roller body 21 and the protrusion 22 are made of different materials.

[0067] In this embodiment, the protrusion 22 can be made of polylactic acid (PLA), acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonate (PC), or polyamide (PA, nylon). The printing method is 3D printing. The roller body 21 is made of metal.

[0068] By using different materials for the outer surfaces of the protrusion 22 and the roller body 21, the bonding force between them is weaker compared to using the same material, thus making it easier to remove the protrusion 22 during shape change. Furthermore, it increases the flexibility in selecting the material for the protrusion 22.

[0069] In some embodiments, the protrusion 22 is a UV-curable inkjet component.

[0070] The UV-curable inkjet component in this embodiment is formed using UV-curable inkjet printing. UV printing refers to a digital printing technology that uses ultraviolet (UV) light to irradiate liquid ink, causing it to cure rapidly. For example, the ink contains a photoinitiator and acrylate monomers / oligomers. When irradiated with ultraviolet light (typically in the UVA band, 320-400nm), the photoinitiator decomposes to generate free radicals or cations, initiating monomer polymerization and causing the liquid ink to cure instantly.

[0071] Specifically, UV printing falls under the category of 2D planar printing. Its principle involves the printhead spraying UV ink onto the surface of the roller body 21, where ultraviolet light rapidly cures the ink to form a pattern. Raised areas 22 can be created through multiple printing cycles.

[0072] For example, the material of the protrusion 22 may include a binder polymer and functional additives. The binder polymer includes acrylic resin, polyurethane resin, rosin-modified resin, or polyvinyl alcohol (PVA). The functional additives include polyamide wax (thickening and anti-settling) and polytetrafluoroethylene micropowder (abrasion and scratch resistance).

[0073] The tension concentration points at the edges of each layer of the tower-shaped Teflon can lead to excessive localized longitudinal tensile force, resulting in problems such as poor consistency in the extension of the tabs and easy breakage of the strip.

[0074] UV-curable inkjet printing relies on ink self-leveling, resulting in a smooth surface and rounded edges after curing. No post-processing is required, minimizing damage to the blank areas. It also offers excellent wear resistance and durability, reducing the risk of breakage caused by excessive stretching and stress concentration at the edges of tower-shaped Teflon.

[0075] Figure 3 This is a schematic diagram of the structure of the protrusion of the stretching roller in some embodiments of the rolling device provided in this application.

[0076] Please see Figure 3 In some embodiments, the protrusion 22 includes a transition sub-section 221 and a stretching sub-section 222. The transition sub-section 221 is attached to the roller body 21, and the stretching sub-section 222 is located on the side of the transition sub-section 221 away from the roller body 21 and is used to stretch the blank area 32 of the film 3. The projection of the stretching sub-section 222 on the transition sub-section 221 along the radial direction of the roller body 21 is located inside the transition sub-section 221.

[0077] In this embodiment, the transition sub-part 221 is attached to the roller body 21, that is, the transition sub-part 221 is directly printed and formed on the roller body 21.

[0078] In this embodiment, the projection of the stretching sub-section 222 along the radial direction of the roller body 21 onto the transition sub-section 221 is located inside the transition sub-section 221, that is, the projection of the stretching sub-section 222 along the radial direction of the roller body 21 onto the transition sub-section 221 is located inside the transition sub-section 221, and the two do not coincide.

[0079] With this configuration, if the stretching portion 222 has a protrusion along the axial direction X of the roller body 21 relative to the transition portion 221, the protrusion will be damaged due to lack of support during continuous stress. Therefore, by setting the projection of the stretching portion 222 along the radial direction of the roller body 21 onto the transition portion 221 within the transition portion 221, the durability of the protrusion 22 can be improved.

[0080] Optionally, the maximum dimension of the protrusion 22 along the axial direction X of the roller body 21 is L1, and L1 is 0 to 2 mm narrower than the width of the blank area 32.

[0081] Optionally, the maximum radial dimension of the transition sub-section 221 along the roller body 21 is H1, and the total thickness of the film region 31 is d, where d≥H1≥d / 2.

[0082] In some embodiments, the stretching sub-section 222 includes a convex curved surface 223 disposed away from the transition sub-section 221. The convex curved surface 223 bulges in the middle region of the roller body 21 in the axial direction X toward the direction away from the transition sub-section 221. The convex curved surface 223 is used to stretch the blank area 32 of the film 3.

[0083] In this embodiment, the convex curved surface 223 has a curved cross-sectional shape in its own surrounding direction.

[0084] In this embodiment, the convex surface 223 can be a convex arc surface or other types of bulging surfaces, such as a parabola.

[0085] For the tabs made in the blank area 32, when passing through the roller, the area near the root of the tab has greater internal stress due to the influence of the film area 31, while the area near the top has less internal stress. Therefore, the top of the tab is less affected by the pulling force at the root of the tab and remains straight. Creases are generated at the edge position of the root force, causing the top to fold.

[0086] The convex curved surface 223 is used to compress and stretch the blank area 32 of the diaphragm 3. The convex curved surface 223 can adapt to the stress conditions at the root and top of the tab. The top of the tab requires greater extension to reduce the stress of bending and warping, so the convex curved surface 223 can better adapt. Furthermore, because the convex curved surface 223 bends smoothly, it can reduce the stress concentration area in the blank area 32, making it less prone to breakage and more suitable for situations where the extension of the blank area 32 is required to be greater. Specifically, according to the product design, such as the tab height and tab width, the shape and size of the convex curved surface 223 are adjusted to achieve a reasonable lateral stretching curve and reduce the tensile tension, thereby improving the folding of the tab.

[0087] For example, since the convex curved surface 223 is difficult to achieve using UV printing, the entire convex portion 22 can be simplified to multi-layer printing. After printing, the ink self-levels and cures uniformly. The height of each layer of the multi-layer steps is 0-30µm, and the number of layers n ranges from 3 to 100. For example, starting from the second layer, each ring has a thickness of 15µm and a width that decreases by 1.5mm, with 30 rings printed. Thickness refers to the radial dimension along the roller body 21, and width refers to the axial dimension along the roller body 21.

[0088] Figure 4 This is another schematic diagram of the protrusion of the stretching roller in some embodiments of the rolling device provided in this application.

[0089] Please see Figure 4In some embodiments, the stretching sub-section 222 includes a stretching surface 224 and two connecting surfaces 225. The stretching surface 224 is disposed opposite to the transition sub-section 221, and each part of the stretching surface 224 is equidistant from the roller body 21. The stretching surface 224 is used to stretch the blank area 32 of the film 3. The two connecting surfaces 225 are respectively disposed on opposite sides of the stretching surface 224 along the axial direction X of the roller body 21. One end of the connecting surface 225 is connected to the stretching surface 224, and the other end is connected to the transition sub-section 221.

[0090] In this embodiment, each part of the stretching surface 224 is equidistant from the roller body 21, that is, the stretching surface 224 is a circumferential surface and each part is equidistant from the roller body 21.

[0091] In this embodiment, the stretching surface 224 is disposed opposite to the transition sub-part 221, that is, the stretching surface 224 is at the greatest distance from the transition sub-part 221 relative to other parts of the stretching sub-part 222.

[0092] In this embodiment, the cross-sectional shape of the connecting surface 225 in the direction surrounding the protrusion 22 can be a straight line extending radially relative to the roller body 21, or a straight line or curve inclined radially relative to the roller body 21.

[0093] Setting each part of the stretching surface 224 to be equidistant from the roller body 21 reduces printing difficulty and facilitates processing.

[0094] Optionally, the dimension of the stretching surface 224 along the axial direction X of the roller body 21 is L3, and the width of the blank area 32 is m, where 0 < L3 ≤ m / 2.

[0095] In some embodiments, the distance between the two connecting surfaces 225 gradually decreases along the direction from the transition sub-part 221 to the stretch sub-part 222.

[0096] The distance between the two connecting surfaces 225 in this embodiment gradually decreases, which may be due to the tilting or bending of one of them, or due to the tilting or bending of both of them together.

[0097] This design allows the tension surface 224 to receive better support, thus improving its service life. Furthermore, it ensures a smooth transition of the tensile force on the blank area 32 at the connecting surface 225, reducing stress concentration areas in the blank area 32.

[0098] In some embodiments, along the direction from the transition sub-part 221 to the stretch sub-part 222, both connecting surfaces 225 are inclined toward each other, and the cross-sectional shape of the connecting surface 225 in its own circumferential direction is a straight line.

[0099] In this embodiment, the inclined setting of the connecting surface 225 means that the cross-sectional shape of the connecting surface 225 in the direction surrounding the protrusion 22 is a straight line inclined relative to the direction of the transition sub-part 221 pointing towards the stretching sub-part 222.

[0100] This design ensures that all parts of the stretching surface 224 are well supported, thus improving its service life. Furthermore, it allows the pressure on the blank area 32 to transition smoothly between the two connecting surfaces 225, further reducing stress concentration areas in the blank area 32.

[0101] For example, the protrusion 22 described above can be UV printed and can be divided into multiple steps, with the number of steps being less than or equal to 5.

[0102] Optionally, the connecting surface 225 and the stretching surface 224 are smoothly connected.

[0103] In this embodiment, the connecting surface 225 and the stretching surface 224 are connected by a curved surface transition.

[0104] The connecting surface 225 and the stretching surface 224 are smoothly connected, so that the substrate is not easily damaged during stretching.

[0105] Please see Figure 3 and Figure 4 In some embodiments, the transition portion 221 protrudes along the axial direction X of the roller body 21 at opposite ends of the stretch portion 222.

[0106] In this embodiment, the transition portion 221 protrudes along the axial direction X of the roller body 21 and is disposed at opposite ends of the stretching portion 222. That is, the projection of the stretching portion 222 on the transition portion 221 along the radial direction of the roller body 21 is spaced from the two edges of the transition portion 221 along the axial direction X of the roller body 21.

[0107] For the tabs made in the blank area 32, when passing through the roller, the area near the root of the tab has greater internal stress due to the influence of the film area 31, while the area near the top has less internal stress. Therefore, the top of the tab is less affected by the pulling force at the root of the tab and remains straight. Creases are generated at the edge position of the root force, causing the top to fold.

[0108] The top of the tab requires greater extension to reduce the stress caused by bending and warping. The transition section 221 protrudes along the axial direction X of the roller body 21 at opposite ends of the stretching section 222. The stretching section 222 corresponds to the area near the non-root portion of the tab. Through stretching, the stress on the tab can be reduced, especially in the area near the top of the tab, thus improving the tab's folding performance. Specifically, based on the product design, such as the tab height and width, the shape and size of the transition section 221 and the stretching section 222 are adjusted to achieve a reasonable lateral stretching curve and lower stretching tension, thereby improving the tab's folding performance.

[0109] In some embodiments, the transition sub-part 221 includes a first surface 226 and a second surface 227 arranged radially opposite to each other along the roller body 21. The first surface 226 is in contact with the roller body 21. There are two second surfaces 227, which protrude from both ends of the stretching sub-part 222 along the axial direction X of the roller body 21. The first surface 226 and the second surface 227 are arranged in parallel and the two second surfaces 227 are coplanar.

[0110] In this embodiment, the second surface 227 is parallel to the first surface 226. Since both surfaces surround the circumference of the roller body 21, they are both circumferential surfaces with equal distances at all points. Coplanar arrangement means that they are located in the same plane, and the distances between the two second surfaces 227 and the first surface 226 are equal.

[0111] It should be noted that in this embodiment, the first surface 226 and the second surface 227 are arranged in parallel, and the two second surfaces 227 are arranged in a coplanar manner, which means that they can be regarded as parallel and coplanar within the allowable range of error.

[0112] Setting the two second surfaces 227 as coplanar makes the forces exerted by the transition sub-section 221 on the blank area 32 at both ends along the axial direction of the roller body 21 the same, improving the symmetry on both sides, which is suitable for the scenario of the blank area 32 located between two film areas 31.

[0113] Optionally, the protrusion 22 is symmetrical about its centerline in the axial direction of the roller body 21.

[0114] For example, the dimension of the second surface 227 along the axial direction of the roller body 21 is L2, where 0 < L2 ≤ 5 mm.

[0115] In one embodiment, there are multiple belt-carrying areas 211 and multiple protrusions 22, which are alternately arranged along the axial direction of the roller body 21.

[0116] For example, the number of protrusions 22 is one more than the number of transport areas 211.

[0117] This setting allows for the stretching of more white space area 32 at the same time, making it suitable for various usage scenarios.

[0118] In one embodiment, the tension roller 2 is a tension floating roller.

[0119] The tension floating roller in this embodiment can dynamically adjust and buffer tension fluctuations. Its control belongs to "passive adjustment" or "semi-active adjustment". The tension will still fluctuate slightly, but the fluctuation range is suppressed within the range allowed by the process.

[0120] Setting the stretching roller 2 as a tension floating roller ensures that the tension of the stretching roller 2 on the diaphragm 3 is approximately constant, always maintaining a high tension, which can better stretch the blank area 32, improve the stretching effect, and reduce the possibility of tape breakage.

[0121] This application also provides a battery production system, including the above-described rolling device 100.

[0122] For example, the battery production system includes a coating device located upstream of the roll forming device 100, which is used to coat a slurry on a substrate to form a film area 31 and a blank area 32, wherein the film area 31 is coated with a slurry coating and the blank area 32 is not coated with a slurry coating.

[0123] For example, the battery production system includes a winding device or a stacking device located downstream of the rolling device 100. The winding device is used to wind a positive electrode sheet, a negative electrode sheet, and a separator to form an electrode assembly, and the stacking device is used to stack a positive electrode sheet, a negative electrode sheet, and a separator to form an electrode assembly.

[0124] Figure 5 This is a schematic diagram of the structure of a stretching roll manufacturing apparatus provided in some embodiments of this application.

[0125] Please see Figure 5 This application also provides a manufacturing apparatus for a stretching roller 2, including a support device 200, a printing device 300, and a driving device 400. The support device 200 supports a roller body 21, which includes a conveyor belt area 211. The printing device 300 prints a protrusion 22 on at least one side of the conveyor belt area 211 along the axial direction of the roller body 21, such that the protrusion 22 protrudes beyond the outer surface of the roller body 21 and is disposed outside the conveyor belt area 211. The driving device 400 drives the roller body 21 to rotate, causing the protrusion 22 to be formed circumferentially around the roller body 21.

[0126] For example, the support device 200 includes a bearing housing connected to the roller body 21.

[0127] For example, the printing device 300 includes a UV printing nozzle, a lead screw assembly, and a lead screw motor. The lead screw assembly includes a screw and a nut. The screw is connected to the lead screw motor and rotates under the drive of the lead screw motor. The screw and the nut are threaded together. The UV printing nozzle is mounted on the nut and moves back and forth along the length of the screw under the drive of the lead screw motor to print multiple protrusions 22.

[0128] For example, drive unit 400 includes a motor.

[0129] Please see Figures 1-3This application provides a roller pressing device 100, including at least one pair of rollers 1 and a stretching roller 2. The at least one pair of rollers 1 are used to press the opposite sides of a film 3. The stretching roller 2 is disposed upstream or downstream of the pair of rollers 1. The stretching roller 2 includes a roller body 21 and a protrusion 22. The roller body 21 includes a conveyor belt area 211 for contacting the film area 31 of the film 3. The protrusion 22 is disposed on at least one side of the conveyor belt area 211 along the axial direction X of the roller body 21, and is disposed outside the conveyor belt area 211. The protrusion 22 surrounds the circumference of the roller body 21 and protrudes from the outer surface of the roller body 21. The protrusion 22 is used to contact and stretch the blank area 32 of the film 3. The protrusion 22 is printed on the roller body 21. The protrusion 22 and the roller body 21 are made of different materials. The protrusion 22 is a UV-curable inkjet part. The protrusion 22 includes a transition sub-section 221 and a stretching sub-section 222. The transition sub-section 221 is attached to the roller body 21, and the stretching sub-section 222 is located on the side of the transition sub-section 221 opposite to the roller body 21 and is used to stretch the blank area 32 of the diaphragm 3. The projection of the stretching sub-section 222 on the transition sub-section 221 along the radial direction of the roller body 21 is located within the transition sub-section 221. The stretching sub-section 222 includes an outwardly convex curved surface 223 disposed opposite to the transition sub-section 221. The outwardly convex curved surface 223 bulges in the middle region of the roller body 21 in the axial direction X in the direction opposite to the transition sub-section 221, and the outwardly convex curved surface 223 is used to stretch the blank area 32 of the diaphragm 3. The transition sub-section 221 protrudes along the axial direction X of the roller body 21 at opposite ends of the stretching sub-section 222. The transition sub-section 221 includes a first surface 226 and a second surface 227 arranged radially opposite to each other along the roller body 21. The first surface 226 is in contact with the roller body 21. There are two second surfaces 227, which protrude from both ends of the stretching sub-section 222 along the axial direction X of the roller body 21. The first surface 226 and the second surface 227 are arranged parallel to each other and are coplanar. There are multiple belt-carrying areas 211 and multiple protrusions 22, which are alternately arranged along the axial direction of the roller body 21. The stretching roller 2 is a tension floating roller.

[0130] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A roller pressing device, characterized in that, include: At least one pair of rollers for extruding the opposite sides of the diaphragm; A stretching roller is disposed upstream or downstream of a pair of rollers. The stretching roller includes a roller body and a protrusion. The roller body includes a conveying area for contacting a film area of ​​the diaphragm. The protrusion is disposed on at least one side of the conveying area along the axial direction of the roller body, and the protrusion is disposed outside the conveying area. The protrusion surrounds the circumference of the roller body and protrudes from the outer surface of the roller body. The protrusion is used to contact and stretch a blank area of ​​the diaphragm. The protrusion is printed on the roller body.

2. The roller pressing device according to claim 1, characterized in that, The outer surface of the roller body and the protrusion are made of different materials.

3. The roller pressing device according to claim 2, characterized in that, The protrusion is a UV-curable inkjet component.

4. The roller pressing device according to claim 1, characterized in that, The protrusion includes a transition sub-section and a stretching sub-section. The transition sub-section is attached to the roller body, and the stretching sub-section is located on the side of the transition sub-section opposite to the roller body and is used to stretch the blank area of ​​the film. The projection of the stretching sub-section on the transition sub-section along the radial direction of the roller body is located within the transition sub-section.

5. The roller pressing device according to claim 4, characterized in that, The stretching sub-section includes a convex curved surface disposed away from the transition sub-section. The convex curved surface bulges outward from the transition sub-section in the central region of the roller body in the axial direction. The convex curved surface is used to stretch the blank area of ​​the film.

6. The roller pressing device according to claim 4, characterized in that, The stretching sub-section includes a stretching surface and two connecting surfaces. The stretching surface is disposed opposite to the transition sub-section, and each part of the stretching surface is equidistant from the roller body. The stretching surface is used to stretch the blank area of ​​the film. The two connecting surfaces are respectively disposed on opposite sides of the stretching surface along the axial direction of the roller body. One end of the connecting surface is connected to the stretching surface, and the other end is connected to the transition sub-section.

7. The roller pressing device according to claim 6, characterized in that, Along the direction from the transition sub-part to the stretching sub-part, the distance between the two connecting surfaces gradually decreases.

8. The roller pressing device according to claim 7, characterized in that, Along the direction from the transition sub-part to the stretching sub-part, both connecting surfaces are inclined toward each other, and the cross-sectional shape of the connecting surfaces in their own circumferential direction is a straight line.

9. The roller pressing device according to any one of claims 4-8, characterized in that, The transition section protrudes along the axial direction of the roller body and is disposed at opposite ends of the stretching section.

10. The roller pressing device according to claim 9, characterized in that, The transition sub-section includes a first surface and a second surface arranged radially opposite to each other along the roller body. The first surface is in contact with the roller body. There are two second surfaces, which protrude from both ends of the stretching sub-section along the axial direction of the roller body. The first surface and the second surface are arranged in parallel, and the two second surfaces are arranged in the same plane.

11. The roller pressing device according to any one of claims 1-8, characterized in that, The number of the belt-carrying area and the number of the protrusions are both multiple, and multiple belt-carrying areas and multiple protrusions are alternately arranged along the axial direction of the roller body.

12. The roller pressing device according to any one of claims 1-8, characterized in that, The stretching roller is a tension floating roller.

13. A battery production system, characterized in that, Includes the roller pressing device as described in any one of claims 1-12.

14. A stretching roll manufacturing equipment, characterized in that, include: A support device is used to support the roller body, the roller body including a belt-carrying area; A printing device is used to print a protrusion on at least one side of the conveyor belt along the axial direction of the roller body in the conveyor belt area, and to make the protrusion protrude from the outer surface of the roller body, and to make the protrusion disposed on the outside of the conveyor belt area; A driving device for driving the roller body to rotate so that the protrusion is formed circumferentially around the roller body.

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