Winding needle mechanism and battery winding equipment

Abstract

The invention discloses a winding needle mechanism and battery winding equipment and belongs to the technical field of batteries. The winding needle mechanism comprises a base, a winding needle ring and a movable piece, the winding needle ring is arranged on the base, the winding needle ring comprises a plurality of connecting pieces, and the connecting pieces are connected in sequence; the movable part is arranged on the base and can drive the winding needle ring to be switched between the first shape and the second shape. In the application, the winding needle ring can be switched between the first shape and the second shape, so that the winding needle ring can be switched into different shapes for different winding stages in the process of producing the electrode assembly by winding the film layer with the winding needle ring, so as to obtain the electrode assembly with better use performance and reliability. Meanwhile, in the switching process of the winding needle ring between the first shape and the second shape, the perimeter of the outer contour of the cross section of the winding needle ring cannot be changed or is slightly changed, so that the risk that a film layer close to the center of the electrode assembly is burst or wrinkled can be reduced, and the safety performance and the use performance of the battery device can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular, to a winding needle mechanism and a battery winding device. Background Art

[0002] In battery production technology, the electrode assembly of a battery cell is usually made by winding to form a wound electrode assembly, and the wound electrode assembly usually uses a winding needle for winding.

[0003] In the related winding process, the winding needles of winding machines generally adopt a cylindrical design. However, there are some deficiencies in the cylindrical winding needles during the winding process. For example, after the cylindrical winding needle winds and discharges materials, the gap between the negative electrode sheet and the positive electrode sheet near the winding center of the electrode assembly will become larger. This gap easily causes uneven distribution of lithium ions during the subsequent use of the battery, and even causes lithium deposition at the winding center of the electrode assembly. Lithium deposition not only causes loss of battery capacity, but also triggers safety hazards such as short circuits or thermal runaway. Summary of the Invention

[0004] An embodiment of the present application provides a winding needle mechanism and a battery winding device, and the electrode assembly obtained by winding the winding needle mechanism has good service performance and reliability.

[0005] In a first aspect, an embodiment of the present application provides a winding needle mechanism, and the winding needle mechanism includes: a base; a winding needle ring, the winding needle ring is arranged on the base, the winding needle ring includes a plurality of connecting members, and the plurality of connecting members are connected in sequence; a movable member, the movable member is arranged on the base, and the movable member can drive the winding needle ring to switch between a first shape and a second shape.

[0006] In the above technical solution, the winding needle ring can switch between a first shape and a second shape. Thus, during the process of the winding needle ring winding a film layer to produce an electrode assembly, at different winding stages, the winding needle ring can be switched into different shapes to obtain an electrode assembly with better service performance and reliability. During the process of the movable member driving the winding needle ring to switch between the first shape and the second shape, the perimeter of the outer contour of the cross section of the winding needle ring does not change or changes little. Therefore, the risk of the film layer near the center of the electrode assembly being broken or wrinkled can be reduced, which is beneficial to improving the safety performance and service performance of the battery device.

[0007] In some embodiments, the movable member includes a first section and a second section. The second section is located between the first section and the base. The movable member is configured to be movable between a first position and a second position. At the first position, the first section is inserted into the winding needle ring, and the second section is located outside the winding needle ring, so that the winding needle ring forms a first shape. At the second position, the second section is inserted into the winding needle ring, so that the winding needle ring forms a second shape.

[0008] In the above technical solution, by making different sections of the movable member have different shapes, when the shape of the winding needle ring needs to be changed, the position of the movable member is directly changed, so that different sections of the movable member are inserted into the winding needle ring. This process can be completed quickly, and the perimeter of the outer contour of the cross-section of the winding needle ring will not change or only change slightly, ensuring the continuity and stability of the winding process, and at the same time ensuring the accuracy and reliability of the shape conversion. At the same time, during the switching process, there is no need to precisely control the moving distance of the movable member, and it is only necessary to insert the movable member into the winding needle ring, so the control difficulty of the movable member can be reduced.

[0009] In some embodiments, the first section and the second section are smoothly connected by a transition surface.

[0010] In the above technical solution, by providing a transition surface, the transition surface is smoothly connected between the outer peripheral surface of the first section and the outer peripheral surface of the second section. In this way, when the movable member switches between the first position and the second position, it will be smoother and can be switched within a very short time, reducing the occurrence of jamming.

[0011] In some embodiments, the cross-section of the first section is rectangular or elliptical, and the cross-section of the second section is circular.

[0012] In the above technical solution, by inserting different sections of the movable member into the winding needle ring, the winding needle ring can be switched between a prismatic shape and a cylindrical shape or between an elliptical cylindrical shape and a cylindrical shape. For example, when winding the film layer near the middle of the electrode assembly, the winding needle ring is prismatic or elliptical cylindrical. In this way, the gap between the positive electrode tab and the negative electrode tab near the winding center of the electrode assembly obtained is smaller. When winding the film layer of the rest of the electrode assembly, the winding needle ring is cylindrical, and the uniformity in the circumferential direction is better, which is beneficial to improving the winding forming efficiency.

[0013] In some embodiments, the base includes a telescopic rod, and the telescopic rod expands and contracts to drive the movable member to move between the first position and the second position.

[0014] In the above technical solution, using a telescopic rod to drive the movable member to move can conveniently achieve the linear translation of the movable member, and the structure is simple and easy to implement.

[0015] In some embodiments, the plurality of the connecting members include a plurality of first connecting members and a plurality of second connecting members, the first connecting members and the second connecting members are arranged alternately in sequence, both ends of the first connecting members have hinge seats, and the hinge seats are respectively hinged to two adjacent second connecting members.

[0016] In the above technical solution, the plurality of first connecting members and the plurality of second connecting members are connected, so that a needle winding ring can be formed, and during the process of switching between the first shape and the second shape of the needle winding ring, the perimeter of the outer contour of the cross section of the needle winding ring remains unchanged or only changes slightly.

[0017] In some embodiments, the needle winding mechanism further includes hinge seats, the hinge seats are arranged at both ends of the connecting members, and for two adjacent connecting members, at least one of the connecting members is hingedly connected to the hinge seat.

[0018] In the above technical solution, the needle winding ring is formed by connecting a plurality of connecting members through a plurality of hinge seats. During the process of switching between the first shape and the second shape of the needle winding ring, the perimeter of the outer contour of the cross section of the needle winding ring remains unchanged or only changes slightly; at the same time, the structures and dimensions of the plurality of connecting members are the same, so that the types of the connecting members can be reduced and the production cost of the connecting members can be lowered.

[0019] In some embodiments, the needle winding mechanism further includes hinge seats, and both ends of each connecting member have the hinge seats, and the hinge seats are hinged to another adjacent connecting member.

[0020] In the above technical solution, the connecting members and the hinge seats are connected to form a connecting unit, and the needle winding ring is formed by connecting a plurality of connecting units, so that during the process of switching between the first shape and the second shape of the needle winding ring, the perimeter of the outer contour of the cross section of the needle winding ring remains unchanged or only changes slightly.

[0021] In some embodiments, the side wall surface of the connecting member includes a flat surface, and the flat surfaces of the plurality of connecting members together form the circumferential outer side surface of the needle winding ring.

[0022] In the above technical solution, the flat surfaces of the plurality of connecting members together form the circumferential outer side surface of the needle winding ring. In this way, at the initial stage of winding, the contact area between the needle winding ring and the film layer is larger, and the fitting effect between the needle winding ring and the film layer is better, which is beneficial to obtaining a better fixing effect.

[0023] In some embodiments, the connecting member has adsorption holes, a vacuum flow path is formed inside the connecting member, and the adsorption holes are connected to an external vacuum source through the vacuum flow path.

[0024] In the above technical solution, adsorption holes are distributed on the surface of the connecting piece, and the film layer is adsorbed by negative pressure to reduce its sliding or offset at the initial stage of winding, ensuring the alignment of the starting end; reducing wrinkles, delamination or spiral misalignment of the film layer due to inertia or uneven tension during high-speed winding.

[0025] In some embodiments, a communication hole is formed on one side of the connecting piece facing the adjacent connecting piece, and the communication hole is communicated with the vacuum flow path.

[0026] In the above technical solution, by providing the communication hole, the vacuum flow paths of adjacent connecting pieces can be interconnected through the communication hole, thereby reducing the number of connecting pipes between the external vacuum source and the connecting piece and reducing the space volume occupied by the connecting pipes.

[0027] In some embodiments, the first shape is a prism or an elliptical cylinder, and the second shape is a cylinder.

[0028] In the above technical solution, when winding the film layer near the middle of the electrode assembly, the winding needle ring is prism-shaped or elliptical cylinder-shaped. In this way, the gap between the positive electrode plate and the negative electrode plate near the winding center of the electrode assembly is smaller, the lithium deposition phenomenon is reduced, which is beneficial to the improvement of the battery capacity and the reduction of safety problems such as short circuit or thermal runaway; when winding the film layer of the rest of the electrode assembly, the winding needle ring is cylinder-shaped, and the circumferential uniformity is better. During winding, the linear velocity is consistent, high-speed winding can be achieved, which is beneficial to improving the winding forming efficiency, and the tension uniformity of each part of the electrode assembly is also better.

[0029] In some embodiments, the size of the winding needle ring of the first shape in the first direction is L1, the size of the winding needle ring of the first shape in the second direction is L2, and the ratio of L1 to L2 is 1:1 to 5:1.

[0030] In the above technical solution, the ratio of L1 to L2 is 1:1 to 5:1. In this way, the gap between the positive electrode plate and the negative electrode plate near the winding center of the obtained electrode assembly can be made smaller, the lithium deposition phenomenon is reduced, which is beneficial to the improvement of the battery capacity and the reduction of safety problems such as short circuit or thermal runaway. At the same time, the ratio of L1 to L2 is not too large to make it difficult to control the tension of the film layer.

[0031] In some embodiments, the winding needle mechanism further includes a connecting rod, and both ends of the connecting rod are movably connected to the winding needle ring and the base respectively, and the connecting rod is configured to be extendable and retractable.

[0032] In the above technical solution, the two ends of the connecting rod are respectively movably connected to the needle winding ring and the base. In this way, the oppositely arranged connecting pieces can approach or move away from each other, so that the shape of the needle winding ring can be changed. At the same time, during the process of the needle winding ring winding the film layer, the connecting rod can also provide a good supporting effect on the needle winding ring, so that the needle winding ring does not move or shake as much as possible except for rotational movement; the connecting rod is configured to be extendable and retractable, so that during the process of the needle winding ring switching between the first state and the second state, the distance between the needle winding ring and the base remains unchanged, reducing the influence on the film layer winding process.

[0033] In some embodiments, one end of the connecting rod is fixedly connected to the needle winding ring, the base is formed with a chute, and the other end of the connecting rod is slidably matched with the chute.

[0034] In the above technical solution, during the process of the movable part being inserted into the needle winding ring from the first section to the second section, the movable part drives the connecting piece to move, so that the connecting piece drives the connecting rod to move, and the connecting piece slides relative to the base. Thus, the oppositely arranged connecting pieces can move relative to each other to change the shape of the needle winding ring, and at the same time, the connecting piece can also provide a good supporting effect on the needle winding ring, so that the needle winding ring does not move or shake as much as possible except for rotational movement.

[0035] In a second aspect, an embodiment of the present application further provides a battery winding device, including the above-mentioned needle winding mechanism, and the needle winding mechanism is used to provide electric energy for the battery winding device.

[0036] In the above technical solution, since the battery winding device includes a needle winding mechanism, the service performance and reliability of the electrode assembly obtained by winding the battery winding device are better. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic structural diagram of a battery winding device provided by some embodiments of the present application; Figure 2 is a first schematic structural diagram of a needle winding mechanism provided by some embodiments of the present application, in which it is shown that the needle winding ring is in the first shape; Figure 3 is a second schematic structural diagram of a needle winding mechanism provided by some embodiments of the present application, in which it is shown that the needle winding ring is in the first shape; Figure 4 is a top view of a needle winding mechanism provided by some embodiments of the present application, in which it is shown that the needle winding ring is in the first shape; Figure 5 is a front view of a needle winding mechanism provided by some embodiments of the present application, in which it is shown that the needle winding ring is in the first shape; Figure 6The first structural schematic diagram of the bobbin ring and the movable part provided by some embodiments of the present application, in which it is shown that the bobbin ring is in the second shape; Figure 7 The top view of the bobbin ring and the movable part provided by some embodiments of the present application, in which it is shown that the bobbin ring is in the second shape; Figure 8 The front view of the bobbin ring and the movable part provided by some embodiments of the present application, in which it is shown that the bobbin ring is in the second shape; Figure 9 The side view of the bobbin ring and the movable part provided by some embodiments of the present application, in which it is shown that the bobbin ring is in the second shape; Figure 10 For Figure 7 The sectional view taken along line A-A in Figure 11 The structural schematic diagram of two connected connecting parts provided by some embodiments of the present application; Figure 12 The top view of two connected connecting parts provided by some embodiments of the present application; Figure 13 The front view of two connected connecting parts provided by some embodiments of the present application; Figure 14 The structural schematic diagram of two connected connecting parts provided by some other embodiments of the present application; Figure 15 The structural schematic diagram of two connected connecting parts provided by some further embodiments of the present application; Figure 16 For Figure 12 The sectional view taken along line B-B in Figure 17 For Figure 4 The enlarged view of part D in Figure 18 The top view of the second connecting part provided by some embodiments of the present application; Figure 19 The three-dimensional structural diagram of the second connecting part provided by some embodiments of the present application; Figure 20 For Figure 18 The sectional view taken along line C-C in Figure 21 The side view of the second connecting part provided by some embodiments of the present application.

[0038] Reference numerals: Battery winding device 1000; Bobbin mechanism 100; Base 10; Expansion rod 101; Bobbin ring 20; Connecting member 201; First connecting member 2011; Second connecting member 2012; Hinge seat 2013; Plane 2014; Adsorption hole 2015; Connecting hole 2016; Vacuum flow path 2017; Movable member 30; First section 301; Second section 302; Transition surface 303; Connecting rod 40; First adjusting roller 410; Second adjusting roller 420; Third adjusting roller 430; Fourth adjusting roller 440; First separator 21; First electrode 11; Second separator 22; Second electrode 12. Detailed implementation manners

[0039] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs; the terms used in the present application in the specification are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0041] Referring to "embodiments" in the present application means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0042] In the description of the present application, it should be noted that, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to", "attached to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0043] In this application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0044] In the embodiments of this application, the same reference numerals represent the same components. For the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width, etc. of the integrated device, are only for illustrative purposes and should not constitute any limitation to this application.

[0045] The term "a plurality of" as used in this application refers to two or more (including two).

[0046] With the development of new energy technologies, batteries are increasingly widely used. Batteries have high energy density, high safety, long service life, and environmental friendliness to the social environment, and have been widely applied in passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, battery swapping stations, engineering manufacturing, intelligent devices, etc. At the same time, it also promotes the technological development and research in aspects such as communication terminals, medical devices, and energy development.

[0047] A battery cell includes a housing, electrode components, and an electrolyte. The electrode components include at least one electrode assembly. The electrode assembly and the electrolyte are both housed in the housing. The electrode assembly includes a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode tab and the negative electrode tab.

[0048] In battery production technology, the electrode assembly of a battery cell is usually made by winding to form a wound electrode assembly. The wound electrode assembly is usually wound using a winding pin.

[0049] In the related winding process, the winding pins of the winding machine generally adopt a cylindrical design. However, there are some deficiencies in the cylindrical winding pins during the winding process. For example, after the cylindrical winding pins wind and cut the material, the gap between the negative electrode tab and the positive electrode tab near the winding center of the electrode assembly will become larger. This gap easily causes uneven distribution of lithium ions during the subsequent use of the battery, and even lithium deposition occurs at the winding center of the electrode assembly. Lithium deposition not only causes loss of battery capacity but also leads to potential safety hazards such as short circuits or thermal runaway.

[0050] Using a flat winding needle for winding can reduce the gap between the negative electrode sheet and the positive electrode sheet at the center of the electrode assembly winding, but the linear velocity of the flat winding needle varies greatly during the winding process, resulting in a large change in acceleration, and excessive acceleration can easily cause impact on the winding drive device. Therefore, the flat winding needle cannot achieve high-speed winding, which restricts the winding forming efficiency and also makes the tension uniformity of the electrode assembly poor. If a prismatic or elliptical winding needle is used for winding in the early stage of winding, and a cylindrical winding needle is used for winding afterwards, a higher forming efficiency can be obtained and the performance and reliability of the electrode assembly are also better.

[0051] The related art discloses a deformable winding needle mechanism, which includes two auxiliary winding needles and two clamping winding needles. The two auxiliary winding needles move away from each other and the two clamping winding needles move toward each other to deform into a cylindrical shape; the two auxiliary winding needles move away from each other and the two clamping winding needles move toward each other to deform into an elliptical cylinder. However, the entire outer circumference of the winding needle mechanism of the above scheme will change. During the shape switching process, the film layer at the winding center of the electrode assembly has a greater risk of being torn and wrinkled.

[0052] In view of the above problems, an embodiment of the present application provides a needle winding mechanism, which includes a base, a needle winding ring and a movable part. The needle winding ring and the movable part are both arranged on the base. The needle winding ring includes multiple connecting parts, and the multiple connecting parts are connected in sequence; the movable part can drive the needle winding ring to switch between a first shape and a second shape.

[0053] In the winding needle mechanism of this structure, the winding needle ring can switch between the first shape and the second shape, so that in different winding stages, the winding needle ring can switch to different shapes to obtain an electrode assembly with better performance and reliability. When the movable part drives the winding needle ring to switch between the first shape and the second shape, the circumference of the cross-sectional outer contour of the winding needle ring will not change or will change slightly, so the risk of the film layer near the center of the electrode assembly being broken or wrinkled can be reduced, which is conducive to improving the safety performance and performance of the battery device.

[0054] The technical solution described in the embodiment of the present application is applicable to a battery winding device. The battery winding device of the embodiment of the present application can be used not only in a production line of lithium-ion batteries, but also in a production line of sodium-ion batteries or other types of battery production lines.

[0055] See also Figure 1 , Figure 1Schematic structural diagram of the battery winding device 1000 provided by some embodiments of the present application. Optionally, the battery winding device 1000 includes adjusting rollers for adjusting the tension of the electrode sheet or the separator. Optionally, the adjusting rollers include: a first adjusting roller 410 for adjusting the tension of the first separator 21; a second adjusting roller 420 for adjusting the tension of the first electrode sheet 11; a third adjusting roller 430 for adjusting the tension of the second separator 22; a fourth adjusting roller 440 for adjusting the tension of the second electrode sheet 12. The number of the first adjusting roller 410, the second adjusting roller 420, the third adjusting roller 430, and the fourth adjusting roller 440 can be one or more. For example, the number of the first adjusting roller 410 is one, the number of the second adjusting roller 420 is two or three, the number of the third adjusting roller 430 is one, and the number of the fourth adjusting roller 440 is two or three.

[0056] During the use of the battery winding device 1000, the first separator 21 is unrolled from the first separator roll and wound around the bobbin ring 20 via the first adjusting roller 410. The first separator roll is used for feeding the first separator 21, and the first adjusting roller 410 is used for adjusting the tension of the first separator 21. Similarly, the first electrode sheet 11 is unrolled from the first electrode sheet roll and wound around the bobbin ring 20 via the second adjusting roller 420, the second separator 22 is unrolled from the second separator roll and wound around the bobbin ring 20 via the third adjusting roller 430, and the second electrode sheet 12 is unrolled from the second electrode sheet roll and wound around the bobbin ring 20 via the fourth adjusting roller 440.

[0057] Please refer to Figures 2 to 10 , Figure 2 The first schematic structural diagram of the bobbin mechanism 100 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the first shape; Figure 3 The second schematic structural diagram of the bobbin mechanism 100 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the first shape; Figure 4 The top view of the bobbin mechanism 100 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the first shape; Figure 5 The front view of the bobbin mechanism 100 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the first shape; Figure 6 The first schematic structural diagram of the bobbin ring 20 and the movable member 30 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the second shape; Figure 7 The top view of the bobbin ring 20 and the movable member 30 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the second shape; Figure 8 The front view of the bobbin ring 20 and the movable member 30 provided by some embodiments of the present application, in which it is shown that the bobbin ring 20 is in the second shape; Figure 9A side view of the winding needle ring 20 and the movable member 30 provided for some embodiments of the present application, wherein it is illustrated that the winding needle ring 20 is in a second shape; Figure 10 for Figure 7 Middle AA section view.

[0058] For the convenience of description, hereinafter, the axial direction refers to the direction of the rotation axis of the base 10 , and the circumferential direction refers to the circumferential direction of the winding needle ring 20 .

[0059] Combination Figures 2 to 10 The needle winding mechanism 100 includes a base 10, a needle winding ring 20 and a movable part 30. The needle winding ring 20 is arranged on the base 10. The needle winding ring 20 includes a plurality of connecting parts 201, and the plurality of connecting parts 201 are connected in sequence; the movable part 30 is arranged on the base 10, and the movable part 30 can drive the needle winding ring 20 to switch between a first shape and a second shape.

[0060] Specifically, the winding needle ring 20 and the movable part 30 are both installed on the base 10. The base 10 is used to install the winding needle mechanism 100 into the battery winding device 1000. The base 10 can rotate to drive the winding needle ring 20 to rotate and wind the positive electrode sheet, the negative electrode sheet and the diaphragm to form an electrode assembly. For the convenience of description, the positive electrode sheet, the negative electrode sheet and the diaphragm are collectively referred to as the film layer below.

[0061] The specific winding process is as follows: the film layer is wound onto the winding needle ring 20, and in the initial multiple turns of winding, the winding needle ring 20 is kept in the first shape, the maximum size of the first shape is larger, and the winding needle ring 20 in the first shape has a larger rotation envelope radius, so the length of the film layer in the suspended state between the winding needle mechanism 100 and the adjusting roller is shorter, that is, the feeding distance is shorter, or the free section of the film layer is shorter, so that the stability of this section of the film layer is better, and thus the coating stability of the film layer after winding is better; at the same time, after the winding is completed, after the electrode assembly is removed from the winding needle ring 20, the gap between the positive electrode sheet and the negative electrode sheet near the winding center of the electrode assembly is smaller, thereby reducing the occurrence of lithium precipitation, which is beneficial to the improvement of battery capacity and the reduction of safety issues such as short circuit or thermal runaway, and thus is beneficial to improving the performance and reliability of the battery device. Exemplarily, the first shape can be a prismatic or elliptical column, and the second shape is a cylindrical shape.

[0062] After completing the initial winding, the movable part 30 drives the winding needle ring 20 to switch from the first shape to the second shape, and the second shape has better circumferential uniformity. For example, the second shape is cylindrical, and the winding needle ring 20 remains in the second shape to wind the film layer until the entire winding process is completed. The subsequent winding process is completed using the second shape winding needle ring 20 with better circumferential uniformity. In this way, during winding, the linear speed is consistent, high-speed winding can be achieved, which is beneficial to improving the winding forming efficiency, and the tension uniformity of each part of the electrode assembly is also better.

[0063] Exemplarily, a plurality of connecting members 201 are connected in sequence. For example, the plurality of connecting members 201 are arranged side by side, and adjacent connecting members 201 are movably connected to each other. The plurality of connecting members 201 are connected to form a ring, so that the coiling needle ring 20 can be switched between a first shape and a second shape. Specifically, the size of the connecting member 201 can be set as small as possible and the number as large as possible, so that the perimeter of the outer contour of the cross section of the coiling needle ring 20 remains unchanged or changes very little. Specifically, the connection positions between the connecting members 201 can be made as close as possible to the outer side of the coiling needle ring 20, so that the perimeter of the outer contour of the cross section of the coiling needle ring 20 remains unchanged or changes very little.

[0064] Exemplarily, the cross section of the connecting member 201 perpendicular to the rotation axis direction of the base 10 can be in the shape of an elliptical cylinder, a square, a triangle, a polygon, a cylinder, etc., and can be selected according to the use effect in practice. Here, the number of the connecting members 201 can be as large as possible, so that after being switched to a cylindrical shape, the connecting member 201 and the film layer can be well attached, and the film layer can be well supported everywhere.

[0065] The coiling needle ring 20 includes a plurality of connecting members 201 and the plurality of connecting members 201 are connected in sequence to form a ring. Therefore, during the process of the coiling needle ring 20 being switched between the first shape and the second shape, the perimeter of the outer contour of the cross section of the coiling needle ring 20 does not change or changes little.

[0066] The coiling needle mechanism 100 according to the embodiment of the present application includes a coiling needle ring 20, and the coiling needle ring 20 can be switched between a first shape and a second shape. Thus, in different winding stages, the coiling needle ring 20 can be switched to different shapes to obtain an electrode assembly with better use performance and reliability. During the process of the moving member 30 driving the coiling needle ring 20 to be switched between the first shape and the second shape, the perimeter of the outer contour of the cross section of the coiling needle ring 20 does not change or changes little. Therefore, the risk of the film layer near the center of the electrode assembly being broken or wrinkled can be reduced, which is beneficial to improving the safety performance and use performance of the battery device.

[0067] In some embodiments, reference may be made to Figures 1 to 10 that the moving member 30 includes a first section 301 and a second section 302, and the moving member 30 is configured to be movable between a first position and a second position; in the first position, the first section 301 is inserted into the coiling needle ring 20, and the second section 302 is located outside the coiling needle ring 20, so that the coiling needle ring 20 forms a first shape; in the second position, the second section 302 is inserted into the coiling needle ring 20, so that the coiling needle ring 20 forms a second shape.

[0068] Specifically, the two end portions of the movable member 30 in the axial direction of the base 10 are respectively a first section 301 and a second section 302. The cross-sections perpendicular to the axial direction of the first section 301 and the second section 302 are different in shape. As a result, when the first section 301 and the second section 302 are inserted into the needle winding ring 20, the shape of the needle winding ring 20 is different. The movable member 30 can move between a first position and a second position. For example, it moves axially between the first position and the second position.

[0069] Exemplarily, the first position can be closer to the base 10, and the second position can be farther from the base 10, that is, the second section 302 is located between the first section 301 and the base 10; or, the first position can be farther from the base 10, and the second position can be closer to the base 10, that is, the first section 301 is located between the second section 302 and the base 10.

[0070] In the above technical solution, by making different sections of the movable member 30 have different shapes, when the shape of the needle winding ring 20 needs to be changed, directly change the position of the movable member 30 so that different sections of the movable member 30 are inserted into the needle winding ring 20. This process can be completed quickly, and it will not change the perimeter of the outer contour of the cross-section of the needle winding ring 20 or cause only a small change in the perimeter of the outer contour of the cross-section of the needle winding ring 20, ensuring the continuity and stability of the winding process, and at the same time guaranteeing the accuracy and reliability of the shape conversion. At the same time, during the switching process, there is no need to precisely control the moving distance of the movable member 30. Just insert the movable member 30 into the needle winding ring 20, so the control difficulty of the movable member 30 can be reduced.

[0071] In addition, when the needle winding ring 20 is in the state of the first shape, the first section 301 is inserted into the needle winding ring 20. In this way, on the one hand, the first section 301 can serve the purpose of supporting the needle winding ring 20, so that the needle winding ring 20 can be stably maintained in the first shape and local deformation of the needle winding ring 20 is not likely to occur; on the other hand, the first section 301 is inserted into the needle winding ring 20, which can play a role of pre-positioning, facilitating the second section 302 to be quickly and accurately inserted into the needle winding ring 20.

[0072] In some other embodiments, there can be multiple movable members 30, and the multiple movable members 30 are respectively connected to multiple connecting members 201 in one-to-one correspondence to drive the multiple connecting members 201 to move one by one to realize the switching of the needle winding ring 20 between the first shape and the second shape.

[0073] In some embodiments, reference can be made to Figure 2 and Figure 3 where the first section 301 and the second section 302 are smoothly connected by a transition surface 303.

[0074] That is, the connection between the first section 301 and the transition curved surface 303 may be tangent to the transition curved surface 303, and the connection between the second section 302 and the transition curved surface 303 may be tangent to the transition curved surface 303. The dimensions of the transition curved surface 303 in each direction are between the dimensions in the corresponding direction of the first section 301 and the dimensions in the corresponding direction of the second section 302, and the dimensions change continuously. Exemplarily, the first section 301 and the second section 302 are connected by a transition portion, and the surface of the transition portion forms the transition curved surface 303, and the transition portion may be a hollow member or a solid member.

[0075] In the above technical solution, by setting a transition surface 303, the transition surface 303 is smoothly connected between the outer peripheral surface of the first section 301 and the outer peripheral surface of the second section 302. In this way, when the movable part 30 switches between the first position and the second position, it will be smoother and the switching can be completed in a very short time, reducing the occurrence of jamming.

[0076] In some embodiments, the cross section of the first section 301 is rectangular or elliptical, and the cross section of the second section 302 is circular. That is, the cross section shape of the first section 301 of the movable member 30 is different from the cross section shape of the second section 302 of the movable member 30. Here, the cross section of the first section 301 and the cross section of the second section 302 both refer to the cross section perpendicular to the axial direction.

[0077] In the above technical solution, the cross-section of the first section 301 is rectangular or elliptical, so that when the first section 301 is inserted in the winding needle ring 20, the outer contour of the cross-section of the winding needle ring 20 is approximately rectangular or elliptical, and the cross-section of the second section 302 is circular, so that when the second section 302 is inserted in the winding needle ring 20, the outer contour of the cross-section of the winding needle ring 20 is approximately circular, thereby realizing the switching of the winding needle ring 20 between a prismatic shape and a cylindrical shape or realizing the switching of the winding needle ring 20 between an elliptical cylindrical shape and a cylindrical shape.

[0078] The winding needle ring 20 can switch between a prismatic shape and a cylindrical shape or between an elliptical shape and a cylindrical shape. For example, when winding the film layer near the middle of the electrode assembly, the winding needle ring 20 is prismatic or elliptical. In this way, the gap between the positive electrode sheet and the negative electrode sheet near the winding center of the electrode assembly is smaller, lithium plating is reduced, the battery capacity is improved, and safety issues such as short circuit or thermal runaway are reduced; when winding the film layer of the rest of the electrode assembly, the winding needle ring 20 is cylindrical, and the circumferential uniformity is good. In this way, during winding, the linear speed is consistent, and high-speed winding can be achieved, which is beneficial to improving the winding forming efficiency, and the tension uniformity of each part of the electrode assembly is also better.

[0079] In some embodiments, reference may be made to Figures 2 to 4, the base 10 includes a telescopic rod 101, and the telescopic rod 101 expands and contracts to drive the movable member 30 to move between a first position and a second position.

[0080] For example, when the movable member 30 located at the first position needs to be switched to the second position, the telescopic rod 101 extends to drive the movable member 30 to translate, so that the second section 302 of the movable member 30 is inserted into the needle winding ring 20. When the movable member 30 located at the second position needs to be switched to the first position, the telescopic rod 101 contracts to drive the movable member 30 to translate, so that the first section 301 of the movable member 30 is inserted into the needle winding ring 20.

[0081] Specifically, the telescopic rod 101 can be an electric telescopic rod, a pneumatic telescopic rod, a hydraulic telescopic rod, or a telescopic member integrated in the base 10 that can expand and contract relative to the base 10, etc. Exemplarily, a plurality of telescopic rods 101 can be provided, and the plurality of telescopic rods 101 are arranged in parallel and are all connected to a movable member 30. In this way, the movement of the movable member 30 is more stable and not prone to deviation.

[0082] In the above technical solution, using the telescopic rod 101 to drive the movable member 30 to move can conveniently realize the linear translation of the movable member 30, and the structure is simple and easy to implement.

[0083] Figure 11 Schematic structural diagram of two connected connecting members 201 provided in some embodiments of the present application; Figure 12 Top view of two connected connecting members 201 provided in some embodiments of the present application; Figure 13 Front view of two connected connecting members 201 provided in some embodiments of the present application.

[0084] In some embodiments, reference can be made to Figures 11 to 13 , a plurality of connecting members 201 include a plurality of first connecting members 2011 and a plurality of second connecting members 2012. The first connecting members 2011 and the second connecting members 2012 are alternately arranged in sequence. Both ends of the first connecting member 2011 have hinge seats 2013, and the hinge seats 2013 are respectively hinged to two adjacent second connecting members 2012.

[0085] Specifically, along the circumferential direction of the needle winding ring 20, second connecting members 2012 are provided on both sides of each first connecting member 2011, and first connecting members 2011 are provided on both sides of each second connecting member 2012. Both ends of the first connecting member 2011 have hinge seats 2013. Here, the hinge seats 2013 can be integrally formed with the first connecting member 2011, so that the assembly process of the first connecting member 2011 and the hinge seats 2013 can be reduced. Alternatively, the hinge seats 2013 are pre-connected to the first connecting member 2011 as a whole, and then the hinge seats 2013 are hingedly connected to the second connecting members 2012. Specifically, hinge sites for hingedly connecting with the second connecting members 2012 are provided at both ends of the hinge seats 2013 along the circumferential direction of the needle winding ring 20.

[0086] In the above technical solution, a plurality of first connecting members 2011 and a plurality of second connecting members 2012 are connected to form the needle winding ring 20, and during the process of switching between the first shape and the second shape of the needle winding ring 20, the perimeter of the outer contour of the cross-section of the needle winding ring 20 remains unchanged or changes slightly.

[0087] Figure 14 FIG. is a schematic structural diagram of two connected connecting members 201 provided in some other embodiments of the present application. In some embodiments, reference may be made to Figure 14 FIG., the needle winding mechanism 100 further includes hinge seats 2013, and the hinge seats 2013 are provided at both ends of the connecting members 201. For two adjacent connecting members 201, at least one connecting member 201 is hingedly connected to the hinge seat 2013.

[0088] Specifically, the hinge seats 2013 are provided at both ends of the connecting members 201 in the axial direction. The hinge seats 2013 and the connecting members 201 are separate parts. In this way, the structures of the connecting members 201 and the hinge seats 2013 are simpler, and the processing difficulty is smaller. After the hinge seats 2013 and the connecting members 201 are respectively formed, they are hingedly connected together. For two adjacent connecting members 201, the ends of the two connecting members 201 can both be hingedly connected to the hinge seat 2013, or for two adjacent connecting members 201, one of the ends of the two connecting members 201 is fixedly connected to the hinge seat 2013, and the other end of the two connecting members 201 is hingedly connected to the hinge seat 2013.

[0089] In the above technical solution, the needle winding ring 20 is formed by connecting a plurality of connecting members 201 through a plurality of hinge seats 2013. During the process of switching between the first shape and the second shape of the needle winding ring 20, the perimeter of the outer contour of the cross-section of the needle winding ring 20 remains unchanged or changes slightly; at the same time, the structures and dimensions of the plurality of connecting members 201 are the same. In this way, the types of the connecting members 201 can be reduced, and the production cost of the connecting members 201 can be lowered.

[0090] Figure 15Schematic diagram of two connected connecting members 201 provided in some embodiments of the present application. In some embodiments, reference may be made to Figure 15 , the needle winding mechanism 100 further includes a hinge seat 2013. Both ends of each connecting member 201 have a hinge seat 2013, and the hinge seat 2013 is hinged to another adjacent connecting member 201.

[0091] Specifically, the hinge seat 2013 and the connecting member 201 are integrally formed, and the connecting member 201 and the hinge seat 2013 are connected to form a connection unit. The structure of each connection unit is the same. In this way, the types of the connecting members 201 can be reduced, and the production cost of the connecting members 201 can be reduced.

[0092] In the above technical solution, the needle winding ring 20 is formed by connecting a plurality of connection units. Thus, during the process of switching between the first shape and the second shape of the needle winding ring 20, the perimeter of the outer contour of the cross-section of the needle winding ring 20 remains unchanged or changes slightly.

[0093] In some embodiments, the side wall surface of the connecting member 201 includes a flat surface 2014, and the flat surfaces 2014 of a plurality of connecting members 201 together form the circumferential outer side surface of the needle winding ring 20.

[0094] Specifically, the other parts of the side wall surface of the connecting member 201 can also be curved surfaces or flat surfaces. In practice, they can be set according to requirements.

[0095] When winding the film layer near the middle of the electrode assembly, that is, in the initial stage of winding, the needle winding ring 20 is prismatic or elliptic cylindrical. In the above technical solution, the flat surfaces 2014 of a plurality of connecting members 201 together form the circumferential outer side surface of the needle winding ring 20. In this way, in the initial stage of winding, the contact area between the needle winding ring 20 and the film layer is larger, and the fitting effect between the needle winding ring 20 and the film layer is better, which is beneficial to obtaining a better fixing effect.

[0096] Figure 16 For Figure 12 Cross-sectional view B-B in Figure 17 For Figure 4 Enlarged view of part D in Figure 18 Top view of the second connecting member provided in some embodiments of the present application; Figure 19 Three-dimensional structure diagram of the second connecting member provided in some embodiments of the present application; Figure 20 For Figure 18 Cross-sectional view C-C in Figure 21 Side view of the second connecting member provided in some embodiments of the present application.

[0097] In some embodiments, reference may be made to Figures 16 to 21, the connecting member 201 has adsorption holes 2015, and a vacuum flow path 2017 is formed inside the connecting member 201. The adsorption holes 2015 are connected to an external vacuum source through the vacuum flow path 2017. More specifically, the adsorption holes 2015 are formed on the plane 2014 that forms the circumferential outer side of the winding needle ring 20 by the connecting member 201.

[0098] In practice, the diameter and spacing of the adsorption holes 2015 can be optimized to maximize the adsorption area while avoiding interference with the winding process. Specifically, for the plurality of adsorption holes 2015 arranged in the axial direction, the spacing between adjacent adsorption holes 2015 can be equal to make the adsorption force uniform everywhere in the axial direction.

[0099] In the above technical solution, the adsorption holes 2015 are distributed on the surface of the connecting member 201. By adsorbing the film layer under negative pressure, its sliding or offset in the initial winding stage is reduced, ensuring the alignment of the starting end and reducing wrinkles, delamination or spiral misalignment of the film layer due to inertia or uneven tension during high-speed winding.

[0100] In some embodiments, reference can be made to Figure 16 and Figure 19 , a communication hole 2016 is formed on one side of the connecting member 201 facing the adjacent connecting member 201, and the communication hole 2016 is communicated with the vacuum flow path 2017.

[0101] Specifically, after the film layer is wound around the winding needle ring 20, it can block the adsorption holes 2015, and at the same time, the communication hole 2016 can be prevented from being directly communicated with the external environment, while the vacuum flow paths 2017 of adjacent connecting members 201 can be communicated with each other.

[0102] In the above technical solution, by providing the communication hole 2016, the vacuum flow paths 2017 of adjacent connecting members 201 can be communicated with each other through the communication hole 2016, so that the number of connection pipes between the external vacuum source and the connecting member 201 can be reduced, and the space volume occupied by the connection pipes can be reduced.

[0103] In some embodiments, reference can be made to Figures 1 to 10 , the first shape is a prism or an elliptical cylinder, and the second shape is a cylinder.

[0104] Specifically, the first shape being a prism or an elliptical cylinder means that the winding needle ring 20 is generally in the shape of a prism or an elliptical cylinder as a whole, and the second shape being a cylinder means that the winding needle ring 20 is generally in the shape of a cylinder as a whole.

[0105] In the above technical solution, when winding the film layer near the middle of the electrode assembly, the winding needle ring 20 is prismatic or elliptical cylindrical. In this way, the gap between the positive electrode tab and the negative electrode tab near the winding center of the electrode assembly is small, the lithium deposition phenomenon is reduced, which is beneficial to the improvement of the battery capacity and the reduction of safety problems such as short circuit or thermal runaway. When winding the film layer of the rest of the electrode assembly, the winding needle ring 20 is cylindrical, and the uniformity in all circumferential directions is good. When winding, the linear velocity is consistent, high-speed winding can be achieved, which is beneficial to improving the winding forming efficiency, and the uniformity of the tension at each part of the electrode assembly is also better.

[0106] In some embodiments, reference may be made to Figure 5 , the dimension of the winding needle ring 20 of the first shape in the first direction is L1, the dimension of the winding needle ring 20 of the first shape in the second direction is L2, and the ratio of L1 to L2 is 1:1 to 5:1.

[0107] Specifically, the second direction is the direction where the minimum dimension of the outer contour of the winding needle ring 20 is located, and the second direction is perpendicular to the first direction. For example, the first direction is Figure 5 the up-down direction in Figure 5 , and the second direction is

[0108] the left-right direction in

[0109] In the above technical solution, the ratio of L1 to L2 is 1:1 to 5:1. In this way, the gap between the positive electrode tab and the negative electrode tab near the winding center of the obtained electrode assembly can be made small, the lithium deposition phenomenon is reduced, which is beneficial to the improvement of the battery capacity and the reduction of safety problems such as short circuit or thermal runaway. At the same time, the ratio of L1 to L2 will not be too large to make it difficult to control the tension of the film layer. Figures 2 to 4 In some embodiments, reference may be made to

[0110] Figures 2 to 4 The two connecting rods 40 are respectively and movably connected to the winding needle ring 20 and the base 10. Specifically, the two ends of the connecting rod 40 are respectively and movably connected to the winding needle ring 20 and the base 10. Exemplarily, one end of the connecting rod 40 is hinged to the winding needle ring 20, for example, hinged to the connecting member 201 or the hinge seat 2013, and the other end of the connecting rod 40 is hinged to the base 10. For example, reference may be made to Figures 2 to 4 , and the hinge seats 2013 of the two relatively arranged connecting members 201 are both movably connected with the connecting rod 40.

[0111] During the process of the movable member 30 being inserted into the coiling needle ring 20 from the first section 301 to the second section 302, since both ends of the connecting rod 40 are movably connected to the coiling needle ring 20 and the base 10 respectively, the angle between the connecting member 201 and the connecting rod 40 can be changed. As a result, the relatively arranged connecting members 201 can move closer to or away from each other, so that the shape of the coiling needle ring 20 can be changed.

[0112] In the above technical solution, both ends of the connecting rod 40 are movably connected to the coiling needle ring 20 and the base 10 respectively. In this way, the relatively arranged connecting members 201 can move closer to or away from each other, so that the shape of the coiling needle ring 20 can be changed. At the same time, during the process of the coiling needle ring 20 coiling the film layer, the connecting rod 40 can also provide a good supporting effect on the coiling needle ring 20, making the coiling needle ring 20 not move or shake as much as possible except for rotational movement. The connecting rod 40 is configured to be extensible and retractable, so that during the process of the coiling needle ring 20 switching between the first state and the second state, the distance between the coiling needle ring 20 and the base 10 remains unchanged, reducing the influence on the film layer coiling process.

[0113] In some embodiments, one end of the connecting rod 40 is fixedly connected to the coiling needle ring 20, and the base 10 is formed with a sliding groove, and the other end of the connecting rod 40 is slidably engaged with the sliding groove.

[0114] Specifically, one end of the connecting rod 40 can be fixedly connected to the hinge seat 2013, or one end of the connecting rod 40 can also be directly fixedly connected to the connecting member 201.

[0115] In the above technical solution, during the process of the movable member 30 being inserted into the coiling needle ring 20 from the first section 301 to the second section 302, the movable member 30 drives the connecting member 201 to move. As a result, the connecting member 201 will drive the connecting rod 40 to move, and the connecting member 201 will slide relative to the base 10. Thus, the relatively arranged connecting members 201 can move relative to each other to change the shape of the coiling needle ring 20, and at the same time, the connecting member 201 can also provide a good supporting effect on the coiling needle ring 20, making the coiling needle ring 20 not move or shake as much as possible except for rotational movement.

[0116] More specifically, by setting a sensor and a controller, the sensor can be used to detect the number of coiling turns of the coiling needle ring 20. According to the detection result of the sensor, the controller can accurately control the switching timing of the movable member from the first position to the second position, ensuring that the shape of the coiling needle ring 20 is converted at an appropriate time, thereby optimizing the coiling process.

[0117] In a second aspect, an embodiment of the present application further provides a battery winding device 1000, which includes the above-mentioned winding needle mechanism 100. Since the battery winding device 1000 includes the above-mentioned winding needle mechanism 100, the service performance of the electrode assembly obtained by winding the film layer by the battery winding device 100 is better and the reliability is higher.

[0118] The battery winding device 1000 can be used to wind the electrode assembly of a lithium-ion battery or the electrode assembly of other types of batteries. The embodiment of the present application can be obtained by improving the existing battery winding device 1000 without significantly changing the device structure, and has good feasibility and industrialization potential.

[0119] The battery winding device 1000 includes a control system. The control system adopts an advanced algorithm and can monitor various parameters during the winding process in real time, such as winding speed, pressure and position, so as to ensure the stability of the winding quality. At the same time, the shape and position of the moving parts can be optimized to avoid interference with the winding process. The material and surface treatment process of the moving parts can be controlled to ensure their durability and reliability.

[0120] It should be noted that, without conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0121] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A needle winding mechanism, characterized in that, Comprising: A base; A needle winding ring, which is arranged on the base and includes a plurality of connecting pieces, and the plurality of connecting pieces are connected in sequence; A movable part, which is arranged on the base and can drive the needle winding ring to switch between a first shape and a second shape.

2. The needle winding mechanism according to claim 1, characterized in that The movable part includes a first section and a second section, and the movable part is configured to be movable between a first position and a second position; In the first position, the first section is inserted into the needle winding ring, and the second section is located outside the needle winding ring, so that the needle winding ring forms a first shape; in the second position, the second section is inserted into the needle winding ring, so that the needle winding ring forms a second shape.

3. The needle winding mechanism according to claim 2, wherein The first section and the second section are smoothly connected by a transition surface.

4. The needle winding mechanism according to claim 2, wherein The cross section of the first section is rectangular or elliptical, and the cross section of the second section is circular.

5. The coiling needle mechanism according to claim 2, wherein The base includes a telescopic rod, and the telescopic rod expands and contracts to drive the movable part to move between the first position and the second position.

6. The coiling needle mechanism according to any one of claims 1-5, characterized in that, The plurality of connecting pieces include a plurality of first connecting pieces and a plurality of second connecting pieces, the first connecting pieces and the second connecting pieces are arranged alternately in sequence, both ends of the first connecting piece have hinge seats, and the hinge seats are respectively hinged to two adjacent second connecting pieces.

7. The winding needle mechanism according to any one of claims 1-5, characterized in that The needle winding mechanism further includes hinge seats, which are arranged at both ends of the connecting piece. For two adjacent connecting pieces, at least one of the connecting pieces is hinged to the hinge seat.

8. The coiling needle mechanism according to any one of claims 1-5, characterized in that, The needle winding mechanism further includes hinge seats, and both ends of each connecting piece have the hinge seats, and the hinge seats are hinged to another adjacent connecting piece.

9. The coiling needle mechanism according to any one of claims 1-5, characterized in that, The side wall surface of the connecting piece includes a plane, and the planes of the plurality of connecting pieces together form the circumferential outer side surface of the needle winding ring.

10. The winding needle mechanism according to any one of claims 1-5, characterized in that, The connecting piece has adsorption holes, a vacuum flow path is formed inside the connecting piece, and the adsorption holes are connected to an external vacuum source through the vacuum flow path.

11. The coiling needle mechanism according to claim 10, characterized in that, A communication hole is formed on one side of the connecting piece facing the adjacent connecting piece, and the communication hole is communicated with the vacuum flow path.

12. The winding needle mechanism according to any one of claims 1-5, characterized in that, The first shape is prismatic or elliptical cylindrical, and the second shape is cylindrical.

13. The coiling needle mechanism according to any one of claims 1-5, characterized in that, The dimension of the needle winding ring in the first shape in the first direction is L1, the dimension of the needle winding ring in the first shape in the second direction is L2, and the ratio of L1 to L2 is 1:1 to 5:

1.

14. The coiling needle mechanism according to any one of claims 1-5, characterized in that, The needle winding mechanism further includes a connecting rod, and both ends of the connecting rod are movably connected to the needle winding ring and the base respectively, and the connecting rod is configured to be extendable and contractible.

15. The needle winding mechanism according to claim 14, wherein One end of the connecting rod is fixedly connected to the needle winding ring, a sliding groove is formed in the base, and the other end of the connecting rod is slidably matched with the sliding groove.

16. A battery winding device, characterized in that, Comprising the needle winding mechanism according to any one of claims 1-15.

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