Coil pin mechanism and battery winding apparatus

Abstract

The application discloses a winding needle mechanism and a battery winding device, 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 and comprises a plurality of connecting pieces which are sequentially connected. The movable piece is arranged on the base and can drive the winding needle ring to switch between a first shape and a second shape. In the application, the winding needle ring can switch between the first shape and the second shape. Therefore, during the process of winding the film layer to produce the electrode assembly, the winding needle ring can be switched into different shapes for different winding stages, so that the electrode assembly with better use performance and reliability can be obtained. Meanwhile, during the switching process of the winding needle ring between the first shape and the second shape, the circumference of the cross-sectional outer contour of the winding needle ring does not change or changes little, so that the risk of the film layer close to the center of the electrode assembly being broken or wrinkled can be reduced, and thus the safety performance and use performance of the battery device can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a needle winding mechanism and a battery winding device. Background Technology

[0002] In battery manufacturing technology, the electrode components of a battery cell are usually made by winding to form a wound electrode component. The wound electrode component is usually wound using a winding needle.

[0003] In related winding processes, the winding needles of winding machines generally adopt a cylindrical design. However, cylindrical winding needles have some shortcomings during the winding process. For example, after the material is wound and cut by cylindrical winding needles, the gap between the negative electrode and the positive electrode near the winding center of the electrode assembly will become larger. This gap can easily lead to uneven distribution of lithium ions during subsequent battery use, and even lithium plating at the winding center of the electrode assembly. Lithium plating not only leads to a loss of battery capacity, but also causes safety hazards such as short circuits or thermal runaway. Summary of the Invention

[0004] This application provides a needle winding mechanism and a battery winding device. The electrode assembly wound by the needle winding mechanism has good performance and reliability.

[0005] In a first aspect, embodiments of this application provide a needle winding mechanism, the needle winding mechanism comprising: a base; a needle winding ring disposed on the base, the needle winding ring including a plurality of connecting members connected in sequence; and a movable member disposed on the base, the movable member being capable of driving the needle winding ring to switch between a first shape and a second shape.

[0006] In the above technical solution, the needle ring can switch between a first shape and a second shape. Therefore, during the production of electrode assemblies by winding the film layer with the needle ring, the needle ring can switch to different shapes at different winding stages to obtain electrode assemblies with better performance and reliability. During the switching process between the first and second shapes, the perimeter of the outer contour of the needle ring's cross-section remains unchanged or changes only slightly. Therefore, the risk of the film layer near the center of the electrode assembly being torn or wrinkled can be reduced, thereby improving the safety and performance of the battery device.

[0007] In some embodiments, the movable member includes a first segment and a second segment, the second segment being located between the first segment and the base, the movable member being configured to move between a first position and a second position; in the first position, the first segment is inserted into the needle coil and the second segment is located outside the needle coil, such that the needle coil forms a first shape; in the second position, the second segment is inserted into the needle coil, such that the needle coil forms a second shape.

[0008] In the above technical solution, by giving different segments of the movable component different shapes, when a change in the shape of the needle coil is required, the position of the movable component is directly changed, allowing the different segments of the movable component to be inserted into the needle coil. This process can be completed quickly and does not change the perimeter of the outer contour of the needle coil's cross-section, or the perimeter changes only slightly, ensuring the continuity and stability of the winding process, while also guaranteeing the accuracy and reliability of shape conversion. Furthermore, the switching process does not require precise control of the movable component's movement distance; simply inserting the movable component into the needle coil is sufficient, thus reducing the difficulty of controlling the movable component.

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

[0010] In the above technical solution, by setting a transition surface, the transition surface smoothly connects the outer peripheral surfaces of the first segment and the second segment. In this way, when the moving part switches between the first position and the second position, it will be smoother and can complete the switch in a very short time, reducing the occurrence of jamming.

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

[0012] In the above technical solution, by inserting different segments of the movable component into the winding ring, the winding ring can be switched between prismatic and cylindrical shapes, or between elliptical and cylindrical shapes. For example, when winding the film layer near the center of the electrode assembly, the winding ring is prismatic or elliptical cylindrical, resulting in a smaller gap between the positive and negative electrode plates near the winding center of the electrode assembly. When winding the remaining film layer of the electrode assembly, the winding ring is cylindrical, resulting in better circumferential uniformity and improving winding efficiency.

[0013] In some embodiments, the base includes a telescopic rod that extends and retracts to drive the movable element to move between the first position and the second position.

[0014] In the above technical solution, the use of a telescopic rod to drive the movement of the moving parts can easily realize the linear translation of the moving parts, and the structure is simple and easy to implement.

[0015] In some embodiments, the plurality of connectors include a plurality of first connectors and a plurality of second connectors, the first connectors and the second connectors being arranged alternately in sequence, the first connectors having hinge seats at both ends, the hinge seats being hinged to two adjacent second connectors respectively.

[0016] In the above technical solution, multiple first connectors and multiple second connectors are connected to form a needle coil, and during the switching between the first shape and the second shape, the perimeter of the outer contour of the cross-section of the needle coil remains unchanged or changes only slightly.

[0017] In some embodiments, the needle winding mechanism further includes a hinge seat located at both ends of the connector, wherein for any two adjacent connectors, at least one connector is hingedly connected to the hinge seat.

[0018] In the above technical solution, the needle coil ring is composed of multiple connectors connected by multiple hinge seats. During the switching between the first and second shapes of the needle coil ring, the perimeter of the outer contour of the cross-section of the needle coil ring remains unchanged or only changes slightly. At the same time, the structure and size of the multiple connectors are the same, which can reduce the types of connectors and reduce the production cost of the connectors.

[0019] In some embodiments, the needle winding mechanism further includes hinge seats, each of the connectors having a hinge seat at both ends, the hinge seats being hinged to an adjacent other connector.

[0020] In the above technical solution, the connector and the hinge seat are connected to form a connecting unit, and the needle coil is composed of multiple connecting units, so that during the process of switching between the first shape and the second shape, the perimeter of the outer contour of the cross-section of the needle coil remains unchanged or only changes slightly.

[0021] In some embodiments, the sidewall surface of the connector includes a plane, and the planes of a plurality of connectors together form the circumferential outer surface of the needle loop.

[0022] In the above technical solution, the planes of multiple connectors together form the circumferential outer surface of the needle ring. In this way, in the initial stage of winding, the contact area between the needle ring and the film layer is larger, the adhesion between the needle ring and the film layer is better, and it is conducive to obtaining a better fixing effect.

[0023] In some embodiments, the connector has an adsorption hole and a vacuum flow path is formed within the connector, and the adsorption hole is connected to an external vacuum source through the vacuum flow path.

[0024] In the above technical solution, the surface of the connector is distributed with adsorption holes, which adsorb the film layer through negative pressure, reducing its slippage or displacement in the initial stage of winding and ensuring the alignment of the starting end; reducing wrinkles, delamination or uneven spirals of the film layer due to inertia or uneven tension during high-speed winding.

[0025] In some embodiments, the connector has a connecting hole on the side facing the adjacent connector, and the connecting hole communicates with the vacuum flow path.

[0026] In the above technical solution, by setting a connecting hole, the vacuum flow paths of adjacent connectors can be connected to each other through the connecting hole, thereby reducing the number of connecting pipes between the external vacuum source and the connectors and reducing the space 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 prismatic or elliptical cylindrical. This results in a smaller gap between the positive and negative electrode plates near the winding center of the electrode assembly, reducing lithium plating and improving battery capacity while reducing safety issues such as short circuits or thermal runaway. When winding the film layer for the remaining part of the electrode assembly, the winding needle ring is cylindrical, resulting in better circumferential uniformity. During winding, the linear speed is consistent, enabling high-speed winding, which improves winding efficiency and also improves the uniformity of tension throughout the electrode assembly.

[0029] In some embodiments, the size of the first-shaped needle loop in the first direction is L1, and the size of the first-shaped needle loop in the second direction is L2, with the ratio of L1 to L2 being 1:1 to 5:1.

[0030] In the above technical solution, the ratio of L1 to L2 is 1:1 to 5:1. This makes the gap between the positive and negative electrode plates near the winding center of the obtained electrode assembly smaller, reducing lithium plating, which is beneficial to improving battery capacity and reducing safety issues such as short circuits or thermal runaway. At the same time, the ratio of L1 to L2 will not be too large, which would make it difficult to control the tension of the film.

[0031] In some embodiments, the needle winding mechanism further includes a connecting rod, the two ends of which are movably connected to the needle winding loop 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 movably connected to the needle ring and the base, respectively. In this way, the relatively arranged connecting parts can move closer or further apart, so that the shape of the needle ring can be changed. At the same time, during the process of the needle ring winding the film, the connecting rod can also provide good support for the needle ring, so that the needle ring will not move or shake except for rotational movement. The connecting rod is constructed to be extendable and retractable, so that the distance between the needle ring and the base remains unchanged during the switching between the first and second states of the needle ring, reducing the impact on the film winding process.

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

[0034] In the above technical solution, during the process of the movable part switching from the first section inserted into the needle coil to the second section inserted into the needle coil, the movable part drives the connecting part to move, thereby the connecting part will drive the connecting rod to move, and the connecting part will slide relative to the base. Thus, the relatively set connecting parts can not only move relative to each other to change the shape of the needle coil, but also provide good support for the needle coil, so that the needle coil will not move or shake except for rotational movement.

[0035] Secondly, embodiments of this application also provide a battery winding device, including the aforementioned winding needle mechanism, which is used to provide electrical energy to the battery winding device.

[0036] In the above technical solution, the battery winding equipment includes a winding needle mechanism, therefore, the electrode assembly wound by the battery winding equipment has better performance and reliability. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of a battery winding device provided in some embodiments of this application;

[0038] Figure 2 The first structural schematic diagram of the needle winding mechanism provided in some embodiments of this application illustrates that the needle winding loop is in a first shape;

[0039] Figure 3 This is a second structural schematic diagram of a needle winding mechanism provided in some embodiments of this application, wherein the needle winding loop is shown to be in a first shape;

[0040] Figure 4 A top view of a needle winding mechanism provided in some embodiments of this application, wherein the needle winding loop is shown in a first shape;

[0041] Figure 5A front view of a needle winding mechanism provided in some embodiments of this application, wherein the needle winding loop is shown in a first shape;

[0042] Figure 6 A first structural schematic diagram of a needle coil and a movable component provided in some embodiments of this application is shown, wherein the needle coil is in a second shape;

[0043] Figure 7 A top view of a needle coil and a movable element provided in some embodiments of this application, wherein the needle coil is shown in a second shape;

[0044] Figure 8 A front view of a needle coil and a movable element provided in some embodiments of this application, wherein the needle coil is shown in a second shape;

[0045] Figure 9 A side view of a needle coil and a movable element provided in some embodiments of this application, wherein the needle coil is shown in a second shape;

[0046] Figure 10 for Figure 7 Sectional view of AA in the middle;

[0047] Figure 11 This is a schematic diagram of the structure of two connected members provided in some embodiments of this application;

[0048] Figure 12 Top view of two connected members provided in some embodiments of this application;

[0049] Figure 13 Front view of two connected members provided in some embodiments of this application;

[0050] Figure 14 Schematic diagrams of two connected members provided in other embodiments of this application;

[0051] Figure 15 This application provides structural schematic diagrams of two connected members in some further embodiments;

[0052] Figure 16 for Figure 12 Cross-sectional view of the middle section (BB);

[0053] Figure 17 for Figure 4 Enlarged view of section D;

[0054] Figure 18 A top view of a second connector provided in some embodiments of this application;

[0055] Figure 19A perspective view of the second connector provided in some embodiments of this application;

[0056] Figure 20 for Figure 18 CC section view;

[0057] Figure 21 A side view of a second connector provided for some embodiments of this application.

[0058] Figure label:

[0059] Battery winding equipment 1000;

[0060] Needle winding mechanism 100;

[0061] Base 10;

[0062] Telescopic pole 101;

[0063] 20-inch coiled needle loop;

[0064] Connector 201; First connector 2011; Second connector 2012; Hinge seat 2013;

[0065] Plane 2014; Adsorption hole 2015; Connecting hole 2016; Vacuum flow path 2017;

[0066] 30 items for the event;

[0067] First segment 301; Second segment 302; Transition surface 303; Connecting rod 40;

[0068] First adjusting roller 410; Second adjusting roller 420; Third adjusting roller 430; Fourth adjusting roller 440;

[0069] First diaphragm 21; first electrode 11; second diaphragm 22; second electrode 12. Detailed Implementation

[0070] 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.

[0071] 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 specification 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 specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, rather than to describe a specific order or hierarchy.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] In this application, "multiple" means two or more (including two).

[0077] With the development of new energy technologies, batteries are being used more and more widely. Batteries have high energy density, high safety, long service life and are environmentally friendly. They have been widely used in passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, battery swapping stations, engineering manufacturing, and intelligent equipment. They also promote the development and research of technologies in communication terminals, medical devices, and energy development.

[0078] A single battery cell includes a casing, electrode components, and an electrolyte. The electrode components include at least one electrode assembly, and both the electrode assembly and the electrolyte are housed within the casing. The electrode assembly includes a positive electrode, a negative electrode, and a separator. The single battery cell primarily functions by the movement of metal ions between the positive and negative electrode plates.

[0079] In battery manufacturing technology, the electrode components of a battery cell are usually made by winding to form a wound electrode component. The wound electrode component is usually wound using a winding needle.

[0080] In related winding processes, the winding needles of winding machines generally adopt a cylindrical design. However, cylindrical winding needles have some shortcomings during the winding process. For example, after the material is wound and cut by cylindrical winding needles, the gap between the negative electrode and the positive electrode near the winding center of the electrode assembly will become larger. This gap can easily lead to uneven distribution of lithium ions during subsequent battery use, and even lithium plating at the winding center of the electrode assembly. Lithium plating not only leads to a loss of battery capacity, but also causes safety hazards such as short circuits or thermal runaway.

[0081] Using flat winding needles reduces the gap between the negative and positive electrodes at the center of the electrode assembly. However, the flat needles exhibit significant linear velocity variations during winding, leading to large acceleration variations. Excessive acceleration can easily impact the winding drive mechanism, thus limiting high-speed winding efficiency and resulting in poor tension uniformity across the electrode assembly. Using prismatic or elliptical cylindrical needles initially, followed by cylindrical needles for subsequent winding, achieves higher forming efficiency and improves the performance and reliability of the electrode assembly.

[0082] Related technologies disclose a deformable needle winding mechanism, which includes two auxiliary needle windings and two clamping needle windings. The two auxiliary needle windings are positioned away from each other, while the two clamping needle windings are positioned towards each other, to deform into a cylindrical shape; alternatively, the two auxiliary needle windings are positioned away from each other, while the two clamping needle windings are positioned towards each other, to deform into an elliptical cylindrical shape. However, the entire outer circumference of the needle winding mechanism in the above scheme changes, and during the shape switching process, there is a significant risk that the film layer at the center of the electrode assembly will be torn and wrinkled.

[0083] In view of the above problems, this application provides a needle winding mechanism, which includes a base, a needle winding ring, and a movable component. The needle winding ring and the movable component are both disposed on the base. The needle winding ring includes multiple connectors that are connected in sequence. The movable component can drive the needle winding ring to switch between a first shape and a second shape.

[0084] In this type of needle winding mechanism, the needle ring can switch between a first shape and a second shape. Thus, at different winding stages, the needle ring can be switched into different shapes to obtain electrode assemblies with better performance and reliability. During the switching process between the first and second shapes, the perimeter of the needle ring's cross-sectional outer contour remains unchanged or changes only slightly. Therefore, the risk of the film layer near the center of the electrode assembly being ruptured or wrinkled is reduced, thereby improving the safety and performance of the battery device.

[0085] The technical solutions described in this application are applicable to battery winding equipment. The battery winding equipment described in this application can be used not only in lithium-ion battery production lines, but also in sodium-ion battery production lines or production lines for other types of batteries.

[0086] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a battery winding apparatus 1000 provided in some embodiments of this application. Optionally, the battery winding apparatus 1000 includes adjusting rollers for adjusting the tension of the electrode sheet or 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; and 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, there may be one first adjusting roller 410, two or three second adjusting rollers 420, one third adjusting roller 430, and two or three fourth adjusting rollers 440.

[0087] During the use of the battery winding equipment 1000, the first separator 21 is unwound from the first separator roll and wound onto the needle ring 20 via the first adjusting roller 410. The first separator roll is used for unloading the first separator 21, and the first adjusting roller 410 is used to adjust the tension of the first separator 21. Similarly, the first electrode 11 is unwound from the first electrode roll and wound onto the needle ring 20 via the second adjusting roller 420, the second separator 22 is unwound from the second separator roll and wound onto the needle ring 20 via the third adjusting roller 430, and the second electrode 12 is unwound from the second electrode roll and wound onto the needle ring 20 via the fourth adjusting roller 440.

[0088] Please refer to Figures 2 to 10 , Figure 2 This is a first structural schematic diagram of a needle winding mechanism 100 provided in some embodiments of this application, wherein the needle winding loop 20 is shown to be in a first shape; Figure 3 This is a second structural schematic diagram of a needle winding mechanism 100 provided in some embodiments of this application, wherein the needle winding loop 20 is shown to be in a first shape; Figure 4 This is a top view of a needle winding mechanism 100 provided in some embodiments of this application, wherein the needle winding loop 20 is shown in a first shape; Figure 5 A front view of a needle winding mechanism 100 provided in some embodiments of this application, wherein the needle winding loop 20 is shown in a first shape; Figure 6 The first structural schematic diagram of the needle coil 20 and the movable member 30 provided in some embodiments of this application shows that the needle coil 20 is in a second shape. Figure 7 A top view of the needle coil 20 and the movable member 30 provided in some embodiments of this application, wherein the needle coil 20 is shown in a second shape; Figure 8 A front view of a needle coil 20 and a movable member 30 provided in some embodiments of this application, wherein the needle coil 20 is shown in a second shape; Figure 9 A side view of the needle coil 20 and the movable member 30 provided in some embodiments of this application, wherein the needle coil 20 is shown in a second shape; Figure 10 for Figure 7 Sectional view of AA.

[0089] For ease of description, in the following text, axial direction refers to the direction of the rotation axis of the base 10, and circumferential direction refers to the direction of the coiling ring 20.

[0090] Combination Figures 2 to 10 The needle winding mechanism 100 includes a base 10, a needle winding ring 20, and a movable member 30. The needle winding ring 20 is disposed on the base 10 and includes multiple connectors 201 connected in sequence. The movable member 30 is disposed on the base 10 and can drive the needle winding ring 20 to switch between a first shape and a second shape.

[0091] Specifically, the needle winding ring 20 and the movable part 30 are both mounted on the base 10. The base 10 is used to mount the needle winding mechanism 100 into the battery winding equipment 1000. The base 10 can rotate to drive the needle winding ring 20 to rotate and wind the positive electrode sheet, negative electrode sheet and separator to form an electrode assembly. For ease of description, the positive electrode sheet, negative electrode sheet and separator are collectively referred to as film layers in the following text.

[0092] The specific winding process is as follows: The film layer is wound onto the needle ring 20, and in the initial multiple turns of winding, the needle ring 20 is kept in a first shape. The maximum size of the first shape is larger, and the rotational envelope radius of the needle ring 20 in the first shape is larger. Therefore, the length of the film layer in a suspended state between the needle winding mechanism 100 and the adjusting roller is shorter, that is, the feed distance is shorter, or the free section of the film layer is shorter. As a result, the stability of this section of the film layer is better, which in turn makes the coating stability of the wound film layer better. At the same time, after the winding is completed, after the electrode assembly is removed from the needle ring 20, the gap between the positive electrode and the negative electrode near the winding center of the electrode assembly is smaller. This can reduce the occurrence of lithium plating, which is beneficial to the improvement of battery capacity and the reduction of safety problems such as short circuit or thermal runaway, thereby improving the performance and reliability of the battery device. For example, the first shape can be prismatic or elliptical cylindrical, and the second shape is cylindrical.

[0093] After the initial winding is completed, the movable part 30 drives the needle ring 20 to switch from the first shape to the second shape. The second shape has better circumferential uniformity. For example, the second shape is cylindrical. The needle ring 20 is kept in the second shape to wind the film layer until the entire winding process is completed. The subsequent winding process is completed by using the needle ring 20 with better circumferential uniformity. In this way, the linear speed is consistent during winding, which can realize high-speed winding, which is beneficial to improve winding forming efficiency. The tension uniformity of the electrode assembly is also better.

[0094] For example, multiple connectors 201 are connected sequentially, such as arranged side by side, with adjacent connectors 201 movably connected to each other, and the multiple connectors 201 are connected to form a loop, so that the needle coil 20 can switch between a first shape and a second shape. Specifically, the size of the connectors 201 can be set as small as possible and the number can be set as large as possible, so that the perimeter of the outer contour of the cross-section of the needle coil 20 remains unchanged or changes very little. Specifically, the connection position between the connectors 201 can be made as close as possible to the outer side of the needle coil 20, so that the perimeter of the outer contour of the cross-section of the needle coil 20 remains unchanged or changes very little.

[0095] For example, the cross-section of the connector 201 perpendicular to the rotation axis of the base 10 can be elliptical, square, triangular, polygonal, cylindrical, etc., and can be selected according to the desired effect in practice. Here, the number of connectors 201 can be as large as possible so that when switched to a cylindrical shape, the connector 201 and the membrane layer can fit well together, so that the membrane layer is well supported in all places.

[0096] The needle coil 20 includes multiple connectors 201, which are sequentially connected to form a ring. Therefore, during the switching between the first and second shapes, the perimeter of the outer contour of the cross-section of the needle coil 20 does not change or changes only slightly.

[0097] The winding mechanism 100 according to an embodiment of this application includes a winding ring 20, which can switch between a first shape and a second shape. Thus, during different winding stages, the winding ring 20 can be switched into different shapes to obtain an electrode assembly with better performance and reliability. During the switching process of the winding ring 20 between the first and second shapes, the perimeter of the outer contour of the cross-section of the winding ring 20 does not change or changes only slightly. Therefore, the risk of the film layer near the center of the electrode assembly being torn or wrinkled can be reduced, thereby improving the safety and performance of the battery device.

[0098] In some embodiments, reference may be made to Figures 1 to 10 The movable member 30 includes a first segment 301 and a second segment 302. The movable member 30 is configured to move between a first position and a second position. In the first position, the first segment 301 is inserted into the needle coil 20, and the second segment 302 is located outside the needle coil 20, so that the needle coil 20 forms a first shape. In the second position, the second segment 302 is inserted into the needle coil 20, so that the needle coil 20 forms a second shape.

[0099] Specifically, the two ends of the movable member 30 in the axial direction of the base 10 are a first segment 301 and a second segment 302, respectively. The cross-sectional shapes of the first segment 301 and the second segment 302 perpendicular to the axial direction are different, so that when the first segment 301 and the second segment 302 are inserted into the needle coil 20, the shape of the needle coil 20 is different. The movable member 30 can move between a first position and a second position, for example, it can move axially between the first position and the second position.

[0100] For example, the first position can be closer to the base 10, and the second position can be farther away from the base 10, that is, the second segment 302 is located between the first segment 301 and the base 10; or, the first position can be farther away from the base 10, and the second position can be closer to the base 10, that is, the first segment 301 is located between the second segment 302 and the base 10.

[0101] In the above technical solution, by making different segments of the movable component 30 have different shapes, when the shape of the winding ring 20 needs to be changed, the position of the movable component 30 is directly changed so that the different segments of the movable component 30 are inserted into the winding ring 20. This process can be completed quickly and does not change the perimeter of the outer contour of the cross-section of the winding ring 20, or the change in the perimeter of the outer contour of the cross-section of the winding ring 20 is small, ensuring the continuity and stability of the winding process, while also ensuring the accuracy and reliability of shape conversion. At the same time, the switching process does not require precise control of the moving distance of the movable component 30; it is only necessary to insert the movable component 30 into the winding ring 20, thus reducing the control difficulty of the movable component 30.

[0102] Furthermore, when the needle coil 20 is in the first shape, the first segment 301 is inserted into the needle coil 20. In this way, on the one hand, the first segment 301 can support the needle coil 20, so that the needle coil 20 can be stably maintained in the first shape and the local deformation of the needle coil 20 is not easy to occur; on the other hand, the insertion of the first segment 301 into the needle coil 20 can play a pre-positioning role, so that the second segment 302 can be quickly and accurately inserted into the needle coil 20.

[0103] In other embodiments, multiple movable members 30 may be provided, and the multiple movable members 30 are connected one-to-one with multiple connectors 201 to drive the multiple connectors 201 to move in a one-to-one correspondence to realize the switching of the needle coil 20 between the first shape and the second shape.

[0104] In some embodiments, reference may be made to Figure 2 and Figure 3 The first segment 301 and the second segment 302 are smoothly connected by the transition surface 303.

[0105] In other words, the connection between the first segment 301 and the transition surface 303 can be tangent to the transition surface 303, and the connection between the second segment 302 and the transition surface 303 can also be tangent to the transition surface 303. The dimensions of the transition surface 303 in each direction are between the dimensions of the first segment 301 in the corresponding direction and the dimensions of the second segment 302 in the corresponding direction, and the dimensions change continuously. For example, the first segment 301 and the second segment 302 are connected by a transition section, the surface of which forms the transition surface 303. The transition section can be a hollow part or a solid part.

[0106] In the above technical solution, by setting a transition surface 303, the transition surface 303 smoothly connects the outer peripheral surface of the first segment 301 and the outer peripheral surface of the second segment 302. In this way, when the moving part 30 switches between the first position and the second position, it will be smoother and can complete the switch in a very short time, reducing the occurrence of jamming.

[0107] In some embodiments, the cross-section of the first segment 301 is rectangular or elliptical, and the cross-section of the second segment 302 is circular. That is, the cross-sectional shape of the first segment 301 of the movable member 30 and the cross-sectional shape of the second segment 302 of the movable member 30 are different. Here, the cross-sections of the first segment 301 and the second segment 302 both refer to the cross-sections perpendicular to the axial direction.

[0108] In the above technical solution, the cross-section of the first segment 301 is rectangular or elliptical, so when the first segment 301 is inserted into the needle coil 20, the outer contour of the cross-section of the needle coil 20 is approximately rectangular or elliptical. The cross-section of the second segment 302 is circular, so when the second segment 302 is inserted into the needle coil 20, the outer contour of the cross-section of the needle coil 20 is approximately circular. This allows the needle coil 20 to switch between prismatic and cylindrical shapes or between elliptical cylindrical and cylindrical shapes.

[0109] The winding ring 20 can switch between prismatic and cylindrical shapes or between elliptical and cylindrical shapes. For example, when winding the film layer near the center of the electrode assembly, the winding ring 20 is prismatic or elliptical cylindrical. This results in a smaller gap between the positive and negative electrode plates near the winding center of the electrode assembly, reducing lithium plating, improving battery capacity, and reducing safety issues such as short circuits or thermal runaway. When winding the film layer for the remaining part of the electrode assembly, the winding ring 20 is cylindrical, resulting in better circumferential uniformity. This ensures good linear speed consistency during winding, enabling high-speed winding, improving winding efficiency, and also improving the uniformity of tension throughout the electrode assembly.

[0110] In some embodiments, reference may be made to Figures 2 to 4 The base 10 includes a telescopic rod 101, which extends and retracts to drive the movable member 30 to move between a first position and a second position.

[0111] For example, when the movable part 30 in the first position needs to be switched to the second position, the telescopic rod 101 extends to drive the movable part 30 to translate, so that the second segment 302 of the movable part 30 is inserted into the needle coil 20. When the movable part 30 in the second position needs to be switched to the first position, the telescopic rod 101 shortens to drive the movable part 30 to translate, so that the first segment 301 of the movable part 30 is inserted into the needle coil 20.

[0112] Specifically, the telescopic rod 101 can be an electric telescopic rod, a pneumatic telescopic rod, a hydraulic telescopic rod, or a telescopic component integrated into the base 10 that can extend and retract relative to the base 10. For example, multiple telescopic rods 101 can be provided, arranged in parallel and all connected to a movable member 30. This makes the movement of the movable member 30 more stable and less prone to deviation.

[0113] In the above technical solution, the telescopic rod 101 is used to drive the movable part 30 to move, which can easily realize the linear translation of the movable part 30. The structure is simple and easy to implement.

[0114] Figure 11 This is a schematic diagram of the structure of two connected members 201 provided in some embodiments of this application; Figure 12 A top view of two connected members 201 provided in some embodiments of this application; Figure 13 This is a front view of two connected members 201 provided in some embodiments of this application.

[0115] In some embodiments, reference may be made to Figures 11 to 13 The multiple connectors 201 include multiple first connectors 2011 and multiple second connectors 2012. The first connectors 2011 and the second connectors 2012 are arranged alternately in sequence. The two ends of the first connector 2011 have hinge seats 2013, and the hinge seats 2013 are respectively hinged to two adjacent second connectors 2012.

[0116] Specifically, along the circumferential direction of the needle coil 20, each first connector 2011 has a second connector 2012 on both sides, and each second connector 2012 has a first connector 2011 on both sides. Each first connector 2011 has a hinge seat 2013 at both ends. Here, the hinge seat 2013 can be integrally formed with the first connector 2011, thereby reducing the assembly process of the first connector 2011 and the hinge seat 2013. Alternatively, the hinge seat 2013 can be pre-connected to the first connector 2011, and then hinged to the second connector 2012. Specifically, each end of the hinge seat 2013 along the circumferential direction of the needle coil 20 has a hinge point for hinged to the second connector 2012.

[0117] In the above technical solution, multiple first connectors 2011 and multiple second connectors 2012 are connected to form a needle coil 20, and during the process of switching between the first shape and the second shape, the perimeter of the outer contour of the cross-section of the needle coil 20 remains unchanged or changes only slightly.

[0118] Figure 14 This is a structural schematic diagram of two connected members 201 provided in other embodiments of this application. In some embodiments, reference may be made to... Figure 14 The needle winding mechanism 100 also includes a hinge seat 2013, which is located at both ends of the connector 201. For two adjacent connectors 201, at least one connector 201 is hingedly connected to the hinge seat 2013.

[0119] Specifically, the hinge seat 2013 is located at both ends of the connector 201 along its axial direction. The hinge seat 2013 and the connector 201 are separate components, which simplifies the structure of both the connector 201 and the hinge seat 2013, making them easier to manufacture. After the hinge seat 2013 and the connector 201 are formed separately, they are hinged together. For two adjacent connectors 201, both ends of the connectors 201 can be hinged to the hinge seat 2013; alternatively, for two adjacent connectors 201, one end of the connector 201 can be fixedly connected to the hinge seat 2013, and the other end of the connector 201 can be hinged to the hinge seat 2013.

[0120] In the above technical solution, the needle coil ring 20 is formed by connecting multiple connectors 201 through multiple hinge seats 2013. During the process of switching between the first shape and the second shape, the perimeter of the outer contour of the cross-section of the needle coil ring 20 remains unchanged or changes only slightly. At the same time, the structure and size of the multiple connectors 201 are the same, which can reduce the types of connectors 201 and reduce the production cost of connectors 201.

[0121] Figure 15 This is a structural schematic diagram of two connected members 201 provided in some embodiments of this application. In some embodiments, reference may be made to... Figure 15 The needle winding mechanism 100 also includes a hinge seat 2013, with each end of each connector 201 having a hinge seat 2013, and the hinge seat 2013 is hinged to the other adjacent connector 201.

[0122] Specifically, the hinge base 2013 and the connector 201 are integrally formed, and the connector 201 and the hinge base 2013 are connected to form a connection unit. Each connection unit has the same structure, which reduces the types of connectors 201 and lowers the production cost of connectors 201.

[0123] In the above technical solution, the needle coil 20 is composed of multiple connecting units, so that during the switching between the first shape and the second shape, the perimeter of the outer contour of the cross-section of the needle coil 20 remains unchanged or changes only slightly.

[0124] In some embodiments, the sidewall surface of the connector 201 includes a plane 2014, and the planes 2014 of the plurality of connectors 201 together form the circumferential outer surface of the needle loop 20.

[0125] Specifically, other parts of the side wall of the connector 201 can be curved or flat, and can be set according to requirements in practice.

[0126] When winding the film layer near the middle of the electrode assembly, i.e., in the initial stage of winding, the winding needle ring 20 is prismatic or elliptical. In the above technical solution, the planes 2014 of multiple connectors 201 together form the circumferential outer surface of the winding needle ring 20. In this way, in the initial stage of winding, the contact area between the winding needle ring 20 and the film layer is larger, and the adhesion between the winding needle ring 20 and the film layer is better, which is conducive to obtaining a better fixing effect.

[0127] Figure 16 for Figure 12 Cross-sectional view of the middle section (BB); Figure 17 for Figure 4 Enlarged view of section D; Figure 18 A top view of a second connector provided in some embodiments of this application; Figure 19 A perspective view of the second connector provided in some embodiments of this application; Figure 20 for Figure 18 CC section view; Figure 21 A side view of a second connector provided for some embodiments of this application.

[0128] In some embodiments, reference may be made to Figures 16 to 21 The connector 201 has an adsorption hole 2015, and a vacuum flow path 2017 is formed inside the connector 201. The adsorption hole 2015 is connected to an external vacuum source through the vacuum flow path 2017. More specifically, the plane 2014 of the connector 201 used to form the circumferential outer side of the needle coil 20 has an adsorption hole 2015.

[0129] In practice, the adsorption area can be maximized by optimizing the design of the diameter and spacing of the adsorption holes 2015, while avoiding interference with the winding process. Specifically, the multiple adsorption holes 2015 arranged along the axial direction can have equal spacing between adjacent adsorption holes 2015 to ensure uniform adsorption force throughout the axial direction.

[0130] In the above technical solution, the surface of the connector 201 is distributed with adsorption holes 2015, which adsorb the film layer through negative pressure, reducing its sliding or offset in the initial stage of winding, ensuring the alignment of the starting end, and reducing the wrinkles, delamination or uneven spirals of the film layer caused by inertia or uneven tension during high-speed winding.

[0131] In some embodiments, reference may be made to Figure 16 and Figure 19 A connecting hole 2016 is formed on the side of the connector 201 facing the adjacent connector 201, and the connecting hole 2016 is connected to the vacuum flow path 2017.

[0132] Specifically, after the film layer is wound onto the needle ring 20, it can block the adsorption hole 2015 and prevent the connecting hole 2016 from being directly connected to the external environment, while the vacuum flow path 2017 of the adjacent connector 201 can be interconnected.

[0133] In the above technical solution, by setting the connecting hole 2016, the vacuum flow path 2017 of adjacent connectors 201 can be connected to each other through the connecting hole 2016, thereby reducing the number of connecting pipes between the external vacuum source and the connector 201 and reducing the space volume occupied by the connecting pipes.

[0134] In some embodiments, reference may be made to Figures 1 to 10 The first shape is a prism or elliptical cylinder, and the second shape is a cylinder.

[0135] Specifically, the first shape is prism or elliptical cylinder, which means that the coiling ring 20 is generally prism or elliptical cylinder in shape, and the second shape is cylindrical, which means that the coiling ring 20 is generally cylindrical in shape.

[0136] 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. This results in a smaller gap between the positive and negative electrode plates near the winding center of the electrode assembly, reducing lithium plating and improving battery capacity while reducing safety issues such as short circuits or thermal runaway. When winding the film layer for the remaining part of the electrode assembly, the winding needle ring 20 is cylindrical, with good circumferential uniformity. During winding, the linear speed is consistent, enabling high-speed winding, which improves winding efficiency and also results in better tension uniformity throughout the electrode assembly.

[0137] In some embodiments, reference may be made to Figure 5 The first-shaped coiled needle loop 20 has a dimension of L1 in the first direction and a dimension of L2 in the second direction. The ratio of L1 to L2 is 1:1 to 5:1.

[0138] Specifically, the second direction is the direction in which the minimum dimension of the outer contour of the coil 20 is located, and the second direction is perpendicular to the first direction. For example, the first direction is... Figure 5 The top and bottom directions, the second direction is Figure 5 The left and right directions in the equation. For example, the ratio of L1 to L2 can be 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, or 5:1.

[0139] In the above technical solution, the ratio of L1 to L2 is 1:1 to 5:1. This makes the gap between the positive and negative electrode plates near the winding center of the obtained electrode assembly smaller, reducing lithium plating, which is beneficial to improving battery capacity and reducing safety issues such as short circuits or thermal runaway. At the same time, the ratio of L1 to L2 will not be too large, which would make it difficult to control the tension of the film.

[0140] In some embodiments, reference may be made to Figures 2 to 4 The needle winding mechanism 100 also includes a connecting rod 40, the two ends of which are movably connected to the needle winding ring 20 and the base 10, respectively. The connecting rod 40 is configured to be extendable and retractable.

[0141] Specifically, the two ends of the connecting rod 40 are movably connected to the needle coil 20 and the base 10, respectively. For example, one end of the connecting rod 40 is hinged to the needle coil 20, such as to the connector 201 or the hinge seat 2013, and the other end of the connecting rod 40 is hinged to the base 10. For example, refer to... Figures 2 to 4 The hinge seats 2013 of the two oppositely arranged connectors 201 are movably connected to the connecting rods 40.

[0142] During the process of switching from the first segment 301 inserted into the needle coil 20 to the second segment 302 inserted into the needle coil 20, since the two ends of the connecting rod 40 are movably connected to the needle coil 20 and the base 10 respectively, the included angle between the connecting member 201 and the connecting rod 40 can be changed, so that the relatively arranged connecting members 201 can move closer or further away from each other, so that the shape of the needle coil 20 can be changed.

[0143] In the above technical solution, the two ends of the connecting rod 40 are movably connected to the needle ring 20 and the base 10, respectively. In this way, the relatively arranged connecting parts 201 can move closer or further apart, so that the shape of the needle ring 20 can be changed. At the same time, during the process of the needle ring 20 winding the film, the connecting rod 40 can also provide good support for the needle ring 20, so that the needle ring 20 will not move or shake except for rotational movement. The connecting rod 40 is constructed to be extendable and retractable, so that the distance between the needle ring 20 and the base 10 remains unchanged during the switching between the first state and the second state, reducing the impact on the film winding process.

[0144] In some embodiments, one end of the connecting rod 40 is fixedly connected to the needle coil 20, the base 10 is formed with a groove, and the other end of the connecting rod 40 is slidably engaged with the groove.

[0145] 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 be directly fixedly connected to the connector 201.

[0146] In the above technical solution, during the process of the movable part 30 switching from the first segment 301 inserted into the needle coil 20 to the second segment 302 inserted into the needle coil 20, the movable part 30 drives the connecting part 201 to move, thereby the connecting part 201 will drive the connecting rod 40 to move, and the connecting part 201 will slide relative to the base 10. Thus, the relatively arranged connecting part 201 can not only move relative to each other to change the shape of the needle coil 20, but also provide good support for the needle coil 20, so that the needle coil 20 will not move or shake except for rotational movement.

[0147] More specifically, by setting up sensors and controllers, the sensors can be used to detect the number of turns of the needle coil 20, and the controller can accurately control the timing of the switching of the moving part from the first position to the second position based on the detection results of the sensors, ensuring that the shape of the needle coil 20 is transformed at the appropriate time, thereby optimizing the winding process.

[0148] Secondly, embodiments of this application also provide a battery winding apparatus 1000, including the aforementioned needle winding mechanism 100. Because the battery winding apparatus 1000 includes the aforementioned needle winding mechanism 100, the electrode assembly obtained by winding the film layer using the battery winding apparatus 100 has better performance and higher reliability.

[0149] The battery winding equipment 1000 can be used to wind electrode components for lithium-ion batteries, as well as electrode components for other types of batteries. The embodiments described in this application can be obtained by improving upon the existing battery winding equipment 1000 without significantly altering the equipment structure, demonstrating good feasibility and industrialization potential.

[0150] The battery winding equipment 1000 includes a control system that employs advanced algorithms to monitor various parameters during the winding process in real time, such as winding speed, pressure, and position, thereby ensuring the stability of winding quality. Simultaneously, the shape and position of moving parts can be optimized to avoid interference with the winding process. The durability and reliability of the moving parts can be ensured by controlling the materials and surface treatment processes of these parts.

[0151] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0152] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A needle winding mechanism, characterized in that, include: Base; A needle coiling ring is disposed on the base, and the needle coiling ring includes multiple connectors connected sequentially. A movable component is disposed on the base and is capable of driving the needle coil to switch between a first shape and a second shape; the movable component includes a first segment and a second segment and is configured to move between a first position and a second position. In the first position, the first segment is inserted into the coiled needle loop, and the second segment is located outside the coiled needle loop, so that the coiled needle loop forms a first shape; in the second position, the second segment is inserted into the coiled needle loop, so that the coiled needle loop forms a second shape; The connector has an adsorption hole and a vacuum flow path is formed inside the connector. The adsorption hole is connected to an external vacuum source through the vacuum flow path. The connector has a connecting hole on the side facing the adjacent connector, and the connecting hole is connected to the vacuum flow path; The first segment and the second segment are smoothly connected by a transition surface; The first segment has a rectangular or elliptical cross-section, and the second segment has a circular cross-section. During different winding stages, the winding needle ring switches to different shapes. When winding the film layer near the middle of the electrode assembly, the winding needle ring is prismatic or elliptical cylindrical, resulting in a smaller gap between the positive and negative electrode plates near the winding center of the electrode assembly. When winding the film layer for the remaining part of the electrode assembly, the winding needle ring is cylindrical.

2. The needle winding mechanism as described in claim 1, characterized in that, The base includes a telescopic rod that extends and retracts to drive the movable element to move between the first position and the second position.

3. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The plurality of connectors include a plurality of first connectors and a plurality of second connectors, the first connectors and the second connectors being arranged alternately in sequence, the first connectors having hinge seats at both ends, the hinge seats being hinged to two adjacent second connectors respectively.

4. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The needle winding mechanism also includes a hinge seat, which is located at both ends of the connector. For any two adjacent connectors, at least one connector is hinged to the hinge seat.

5. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The needle winding mechanism further includes hinge seats, each of the connectors having a hinge seat at both ends, the hinge seat being hinged to the adjacent connector.

6. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The sidewall of the connector includes a plane, and the planes of multiple connectors together form the circumferential outer surface of the needle coil.

7. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The first shape is a prism or an elliptical cylinder, and the second shape is a cylinder.

8. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The first-shaped coiled needle loop has a dimension L1 in the first direction and a dimension L2 in the second direction. The ratio of L1 to L2 is 1:1 to 5:

1. The second direction is the direction in which the minimum dimension of the outer contour of the coiled needle loop is located, and the second direction is perpendicular to the first direction.

9. The needle winding mechanism as described in any one of claims 1-2, characterized in that, The needle winding mechanism also includes a connecting rod, the two ends of which are movably connected to the needle winding ring and the base, respectively, and the connecting rod is configured to be extendable and retractable.

10. The needle winding mechanism as described in claim 9, characterized in that, One end of the connecting rod is fixedly connected to the needle coiling ring, the base has a sliding groove, and the other end of the connecting rod is slidably engaged with the sliding groove.

11. A battery winding device, characterized in that, Includes the needle winding mechanism as described in any one of claims 1-10.

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