Winding device and battery production system

Abstract

The embodiment of the utility model provides a winding device and a battery production system.The winding device comprises a winding needle structure and a driving part, the winding needle structure comprises a first winding needle and a second winding needle which are oppositely arranged, and at least one of the first winding needle and the second winding needle comprises a main body part and an avoiding part which are arranged in the axial direction of the winding needle structure; the main body part is used for winding a positive pole piece, an isolating membrane and a negative pole piece to form an electrode assembly, the positive pole piece and the negative pole piece both comprise tabs, the avoiding part is configured to face the tabs, and in the radial direction of the winding needle structure, the avoiding surface, used for facing the tabs, in the avoiding part is lower than the winding surface, used for winding the electrode assembly, in the main body part; the first winding needle and the second winding needle are both connected with the driving piece, and the driving piece is used for driving the first winding needle and the second winding needle to rotate synchronously. The reliability of the battery monomer can be improved.

Description

Technical Field

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

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

[0003] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Utility Model Content

[0004] This application provides a winding device and a battery production system that can improve the reliability of individual battery cells.

[0005] This application provides a winding device, including a winding needle structure and a driving member. The winding needle structure includes a first winding needle and a second winding needle disposed opposite to each other. At least one of the first winding needle and the second winding needle includes a main body portion and a clearance portion arranged along the axial direction of the winding needle structure. The main body portion is used to wind a positive electrode sheet, a separator, and a negative electrode sheet to form an electrode assembly. Both the positive electrode sheet and the negative electrode sheet include electrode tabs. The clearance portion is configured to face the electrode tabs. Along the radial direction of the winding needle structure, the clearance surface of the clearance portion for facing the electrode tabs is lower than the winding surface of the main body portion for winding the electrode assembly. Both the first winding needle and the second winding needle are connected to the driving member, and the driving member is used to drive the first winding needle and the second winding needle to rotate synchronously.

[0006] In the above technical solution, the winding device of this embodiment is configured to include a main body and a relief part by setting at least one of the first winding needle and the first winding needle. The relief surface of the relief part is lower than the winding surface of the main body. In this way, during the winding process, there is a gap between the relief surface and the tab, thereby reducing the influence of negative pressure on the tab, that is, reducing the possibility of the tab contacting the relief part. Therefore, it reduces the possibility of the tab being flipped when the winding needle is pulled out, thereby reducing the risk of short circuit between the positive and negative electrode plates of the subsequent battery cell caused by the tab flipping, and improving the reliability of the battery cell.

[0007] In some embodiments, both the first and second winding needles include a main body and a clearance portion. The clearance surface of the first winding needle extends circumferentially along the winding needle structure to the entire outer surface of the first winding needle facing away from the second winding needle, and the clearance surface of the second winding needle extends circumferentially along the winding needle structure to the entire outer surface of the second winding needle facing away from the first winding needle.

[0008] The above technical solution can improve the applicability of the winding needle structure, that is, it is still applicable to different positions of the electrode tab in the winding needle structure, thus improving the convenience of using the winding device.

[0009] In some embodiments, the clearance surface includes a first end near the winding surface and a second end away from the winding surface, and the first end and the second end have the same recess depth relative to the winding surface along the radial direction of the needle winding structure.

[0010] In the above technical solution, the indentation depth of the first end and the second end relative to the winding surface is the same, that is, the distance between the first end and the second end and the electrode tab is the same, thereby better reducing the influence of negative pressure on the electrode tab.

[0011] In some embodiments, the recess depth of the avoidance surface relative to the winding surface is the same at all points along the radial direction of the needle winding structure.

[0012] The above technical solution facilitates the processing and manufacturing of the coiled needle structure.

[0013] In some embodiments, the first and second winding needles further include a transition portion, the main body portion, the transition portion and the clearance portion are arranged and connected sequentially along the axial direction of the winding needle, and the transition portion includes a transition surface for facing the electrode assembly, the transition surface being an inclined plane or a curved surface.

[0014] In the above technical solution, a transition section is provided to facilitate the cleaning of the first coil of needles and reduce the residue of contaminants.

[0015] In some embodiments, the clearance portion further includes a protrusion disposed on the clearance surface and used to support the electrode tab.

[0016] In the above technical solution, a protrusion is provided to support the electrode tab, which not only reduces the impact of negative pressure on the electrode tab, but also reduces the phenomenon that the electrode tab may bend due to the retracted coiling needle structure.

[0017] In some embodiments, the protrusion is a strip-shaped protrusion that extends circumferentially along the needle coil.

[0018] In the above technical solution, setting the protrusion as a strip-shaped protrusion provides better support for the electrode tab.

[0019] In some embodiments, there are multiple protrusions, which are spaced apart circumferentially along the needle coil structure.

[0020] In the above technical solution, the protrusions are set as multiple and spaced apart along the circumference of the winding needle. In this way, the spaced protrusions can further reduce the impact of negative pressure on the electrode tab and reduce the possibility of the electrode tab bending.

[0021] In some embodiments, along the radial direction of the needle winding structure, the recess depth of the avoidance surface relative to the winding surface is h1, where h1 satisfies: 2mm≤h1≤5mm.

[0022] In the above technical solution, the value of h1 is limited to greater than or equal to 2mm to increase the distance between the electrode tab and the clearance surface, reduce the influence of negative pressure on the electrode tab and the possibility of contact between the two, and further reduce the possibility of the electrode tab being bent by the winding needle structure; the value of h1 is limited to less than or equal to 5mm to improve the structural strength of the clearance part.

[0023] In some embodiments, h1 satisfies: 2mm≤h1≤3mm.

[0024] In the above technical solution, the value of h1 is limited to less than or equal to 3mm in order to further improve the structural strength of the avoidance part.

[0025] In some embodiments, the first winding needle has a first groove extending axially along the winding needle structure, the first groove penetrating a portion of the winding surface and a portion of the avoidance surface, and the second winding needle has a second groove extending axially along the winding needle structure, the second groove penetrating a portion of the winding surface and a portion of the avoidance surface, and the first groove and the second groove are arranged radially spaced along the winding needle structure.

[0026] In the above technical solution, a first groove and a second groove are provided to facilitate the two clamping pins to extend into the first groove and the second groove respectively to clamp the electrode assembly, thereby allowing the coiled pin structure to exit from the electrode assembly.

[0027] Secondly, embodiments of this application also provide a battery production system, including the winding device described above. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a battery production system provided in some embodiments of this application;

[0030] Figure 2 This is a schematic diagram of the structure of a winding device provided in some embodiments of this application;

[0031] Figure 3 This is a schematic diagram of the coiled needle structure provided in some embodiments of this application;

[0032] Figure 4 A cross-sectional view of a coiled needle structure provided in some embodiments of this application;

[0033] Figure 5 for Figure 4 Enlarged view at point A;

[0034] Figure 6 This is a schematic diagram of the structure of the first coiled needle in some embodiments of this application.

[0035] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0036] 100. Battery production system; 200. Electrode coating equipment; 300. Drying equipment; 400. Winding equipment;

[0037] 1. Needle winding structure; 11. First needle winding; 12. Second needle winding; 13. Main body; 131. Winding surface; 14. Clearance part; 141. Clearance surface; 142. Protrusion; 15. Transition part; 151. Transition surface; 16. First groove; 17. Second groove;

[0038] 2. Driving components;

[0039] 3. Electrode assembly; 31. Tab;

[0040] 4. Turntable. Detailed Implementation

[0041] 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.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] In this application, "multiple" means two or more (including two).

[0048] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0049] A single battery cell includes electrode components and an electrolyte. The electrode components include a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer, which is coated on the surface of the positive current collector. The positive current collector includes a positive electrode coating area and a positive electrode tab connected to the coating area. The coating area is coated with the positive active material layer, while the tab is not. Taking a lithium-ion battery cell as an example, the positive current collector can be made of aluminum, and the positive active material layer includes the positive active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector. The negative current collector includes a negative electrode coating area and a negative electrode tab connected to the negative electrode coating area. The negative electrode coating area is coated with the negative active material layer, while the negative electrode tab is not coated with the negative active material layer. The material of the negative current collector can be copper, and the negative active material layer includes negative active material, which can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0050] The winding needle is used to wind the positive electrode, separator, and negative electrode to form an electrode assembly. After winding, the winding needle needs to be pulled back. During this pulling process, due to the low air pressure between the winding needle and the tabs, the air pressure causes the inner tabs to fold. This folded tab can then fold the separator between the positive and negative electrodes, potentially causing the tabs to touch the opposite electrode, resulting in a short circuit between the positive and negative electrodes. Furthermore, the folded tabs can lead to incomplete soldering in subsequent processes, affecting battery capacity and lifespan. This can also cause lithium plating on the corresponding electrodes, and the deposited metal may puncture the separator, leading to another short circuit between the positive and negative electrodes.

[0051] In view of this, this application provides a winding device that provides a clearance portion on the first winding needle and the second winding needle. The clearance surface of the clearance portion is low and corresponds to the tab and forms a gap. In this way, the possibility of the tab contacting the clearance portion can be reduced, thus reducing the possibility of the tab being flipped when the winding needle is pulled out. This reduces the risk of short circuit between the positive and negative electrode plates of the subsequent battery cell caused by the tab flipping, thereby improving the reliability of the battery cell.

[0052] Figure 1 This is a schematic diagram of the structure of a battery production system provided in some embodiments of this application.

[0053] like Figure 1As shown, this application provides a battery production system 100, which includes a winding device 400 for winding a positive electrode sheet, a separator and a negative electrode sheet to form an electrode assembly 3.

[0054] For example, the battery production system 100 also includes an electrode coating device 200 for coating active material on at least one side of the current collector.

[0055] For example, the battery production system 100 also includes a drying device 300, which is located downstream of the electrode coating device 200 and upstream of the winding device 400. The drying device 300 is used to dry the current collector coated with active material to form a dry electrode.

[0056] Figure 2 This is a schematic diagram of the structure of a winding device provided in some embodiments of this application; Figure 3 This is a schematic diagram of the coiled needle structure provided in some embodiments of this application; Figure 4 A cross-sectional view of a coiled needle structure provided in some embodiments of this application; Figure 5 for Figure 4 Enlarged view at point A.

[0057] like Figures 2-5 As shown, this application also provides a winding device 400, including a winding needle structure 1 and a driving member 2. The winding needle structure 1 includes a first winding needle 11 and a second winding needle 12 disposed opposite to each other. At least one of the first winding needle 11 and the second winding needle 12 includes a main body portion 13 and a clearance portion 14 arranged along the axial direction of the winding needle structure 1. The main body portion 13 is used to wind a positive electrode sheet, a separator, and a negative electrode sheet to form an electrode assembly 3. Both the positive electrode sheet and the negative electrode sheet include an electrode tab 31. The clearance portion 14 is configured to face the electrode tab 31. Along the radial direction of the winding needle structure 1, the clearance surface 141 of the clearance portion 14 for facing the electrode tab 31 is lower than the winding surface 131 of the main body portion 13 for winding the electrode assembly 3. The first winding needle 11 and the second winding needle 12 are both connected to the driving member 2, and the driving member 2 is used to drive the first winding needle 11 and the second winding needle 12 to rotate synchronously.

[0058] For example, the first coil needle 11 and the second coil needle 12 are arranged opposite each other and the distance between them is variable, that is, the first coil needle 11 and the second coil needle 12 can move closer to each other or further away from each other along the radial direction of the coil needle structure 1. For example, the ends of the first coil needle 11 and the second coil needle 12 can be movably arranged on the turntable 4, and the driving member 2 drives the turntable 4 to rotate, thereby driving the first coil needle 11 and the second coil needle 12 to rotate synchronously.

[0059] In this embodiment, the winding surface 131 of the main body 13 refers to the outer surface of the main body 13 used for winding the electrode assembly 3, which is a curved surface. Furthermore, the winding surface 131 is an arc-shaped surface.

[0060] In this embodiment, the avoidance surface 141 of the avoidance portion 14 refers to the outer surface of the avoidance portion 14 facing the tab 31. It can be a curved surface that bends circumferentially along the needle winding structure 1, or it can be formed as multiple planes that bend circumferentially along the needle winding structure 1. Further optionally, the avoidance surface 141 is an arc-shaped surface.

[0061] In this embodiment, the recess depth of the avoidance surface 141 relative to the winding surface 131 can be the same or different at various points. For example, along the arrangement direction from the main body portion 13 to the avoidance portion 14, the recess depth of the avoidance surface 141 relative to the winding surface 131 gradually increases.

[0062] Optionally, the end of the coiled needle structure 1 is a clearance portion 14.

[0063] In this embodiment, the clearance surface 141 can face the entire tab 31, or a portion of the tab 31, or not only the tab 31, but also the portions of the positive and negative electrode plates coated with active material.

[0064] In this embodiment, the clearance surface 141 is lower than the winding surface 131 along the radial direction of the needle winding structure 1, that is, the clearance surface 141 is lower than the winding surface 131 at all points. The surface connecting the winding surface 131 and the clearance surface 141 can be connected to the two at an obtuse angle, a right angle or an acute angle, respectively.

[0065] Optionally, both the first and second coils of needle 11 include a main body portion 13 and a clearance portion 14 arranged along the axial direction of the coil structure 1. In this case, the lengths of the clearance portions 14 along the axial direction of the coil structure 1 can be the same or different. The depths of the clearance surfaces 141 relative to the winding surfaces 131 can be the same or different.

[0066] In this embodiment, the clearance surface 141 can extend along the circumference of the needle coiling structure 1 to the entire first needle coil 11 or to a portion of the first needle coil 11. Similarly, the clearance surface 141 can extend along the circumference of the needle coiling structure 1 to the entire second needle coil 12 or to a portion of the second needle coil 12.

[0067] The winding device 400 of this embodiment configures at least one of the first winding needle 11 and the second winding needle 12 to include a main body 13 and a clearance portion 14. The clearance surface 141 of the clearance portion 14 is lower than the winding surface 131 of the main body 13. In this way, during the winding process, the clearance surface 141 has a gap with the tab 31, thereby reducing the influence of negative pressure on the tab 31, that is, reducing the possibility of the tab 31 contacting the clearance portion 14. Therefore, it reduces the possibility of the tab 31 being folded when the winding needle structure 1 is pulled out, thereby reducing the risk of short circuit between the positive and negative electrode plates caused by the folding of the tab 31 in subsequent battery cells, and improving the reliability of the battery cells.

[0068] In some embodiments, the first winding needle 11 and the second winding needle 12 both include a main body portion 13 and a clearance portion 14. The clearance surface 141 of the first winding needle 11 extends circumferentially along the winding needle structure 1 to the entire outer surface of the first winding needle 11 facing away from the second winding needle 12, and the clearance surface 141 of the second winding needle 12 extends circumferentially along the winding needle structure 1 to the entire outer surface of the second winding needle 12 facing away from the first winding needle 11.

[0069] In this embodiment, the clearance surface 141 of the first winding needle 11 extends circumferentially along the winding needle structure 1 to the entire outer surface of the first winding needle 11 facing away from the second winding needle 12, excluding the surface of the first winding needle 11 facing the second winding needle 12. Similarly, the clearance surface 141 of the second winding needle 12 extends circumferentially along the winding needle structure 1 to the entire outer surface of the second winding needle 12 facing away from the first winding needle 11.

[0070] This configuration improves the applicability of the winding needle structure 1, meaning it is applicable to different positions of the tab 31 in the winding needle structure 1, thus enhancing the ease of use of the winding device 400.

[0071] In some embodiments, the clearance surface 141 includes a first end near the winding surface 131 and a second end away from the winding surface 131. Along the radial direction of the needle winding structure 1, the first end and the second end have the same recess depth relative to the winding surface 131.

[0072] The first and second ends have the same depth of indentation relative to the winding surface 131, that is, the distance between the first and second ends and the tab 31 is the same, thereby reducing the influence of negative pressure on the tab 31.

[0073] In some embodiments, the recess depth of the avoidance surface 141 relative to the winding surface 131 is the same at all points along the radial direction of the needle winding structure 1.

[0074] This design facilitates the processing and fabrication of the coiled needle structure 1.

[0075] In some embodiments, the end of the winding surface 131 near the clearance surface 141 is configured to contact the root of the tab 31.

[0076] In this embodiment, the root of the tab 31 refers to the part where the tab 31 is connected to the coating area of ​​the positive or negative electrode sheet.

[0077] With this configuration, the winding surface 131 supports the root of the tab 31, reducing the possibility of the tab 31 bending due to lack of support and the need for the winding needle structure 1 to be pulled out.

[0078] In some embodiments, the first winding needle 11 and the second winding needle 12 further include a transition portion 15. The main body portion 13, the transition portion 15 and the clearance portion 14 are arranged and connected sequentially along the axial direction of the winding needle structure 1. The transition portion 15 includes a transition surface 151 for facing the electrode assembly 3. The transition surface 151 is an inclined plane or a curved surface.

[0079] In this embodiment, the shape of the transition portion 15 between the first coil needle 11 and the second coil needle 12 can be the same or different.

[0080] The transition section 15 facilitates cleaning of the first coil of needles 11 and the second coil of needles 12, reducing the residue of contaminants.

[0081] Figure 6 This is a schematic diagram of the structure of the first coiled needle in some embodiments of this application.

[0082] Please see Figure 6 In some embodiments, the clearance portion 14 further includes a protrusion 142, which is disposed on the clearance surface 141 and is used to support the tab 31.

[0083] The protrusion 142 in this embodiment can be strip-shaped or block-shaped.

[0084] In this embodiment, the protrusion 142 is used to support the tab 31. Its height can be the same as or lower than the winding surface 131, but cannot be higher than the winding surface 131.

[0085] The protrusion 142 is provided to support the tab 31, which reduces the impact of negative pressure on the tab 31 and also reduces the phenomenon that the tab 31 may bend due to the coiled needle structure 1 being pulled out.

[0086] In some embodiments, the protrusion 142 is a strip protrusion 142 that extends circumferentially along the needle coil structure 1.

[0087] In this embodiment, the number of strip protrusions 142 can be one or more. The multiple strip protrusions 142 can be spaced apart circumferentially along the needle coiling structure 1 or spaced apart axially along the needle coiling structure 1.

[0088] Setting the protrusion 142 as a strip protrusion 142 provides better support for the tab 31.

[0089] In some embodiments, the number of protrusions 142 is multiple, and the multiple protrusions 142 are arranged at circumferential intervals along the needle coil structure 1.

[0090] In this embodiment, a plurality of protrusions 142 are arranged at intervals along the circumference of the needle winding structure 1. The shape of the plurality of protrusions 142 can be block-shaped or strip-shaped. The strip-shaped protrusions 142 can extend along the axial direction of the needle winding structure 1.

[0091] By setting multiple protrusions 142 and spacing them circumferentially along the coiling structure 1, the spaced protrusions 142 can further reduce the impact of negative pressure on the tab 31 and reduce the possibility of the tab 31 bending.

[0092] In some embodiments, along the radial direction of the needle winding structure 1, the recess depth of the avoidance surface 141 relative to the winding surface 131 is h1, where h1 satisfies: 2mm≤h1≤5mm.

[0093] Optionally, the value of h1 can be 2mm, 3mm, 4mm or 5mm.

[0094] The value of h1 is limited to greater than or equal to 2 mm to increase the distance between the tab 31 and the clearance surface 141, reduce the influence of negative pressure on the tab 31 and the possibility of contact between the two, and further reduce the possibility of the tab 31 being bent by the winding needle structure 1; the value of h1 is limited to less than or equal to 5 mm to improve the structural strength of the clearance part 14.

[0095] In some embodiments, h1 satisfies: 2mm≤h1≤3mm.

[0096] Optionally, the value of h1 can be 2mm, 2.5mm or 3mm.

[0097] The value of h1 is limited to less than or equal to 3 mm to further improve the structural strength of the clearance part 14.

[0098] Please see Figure 3 In some embodiments, the first winding needle 11 is provided with a first groove 16 extending axially along the winding needle structure 1, the first groove 16 penetrating a portion of the winding surface 131 and a portion of the avoidance surface 141, the second winding needle 12 is provided with a second groove 17 extending axially along the winding needle structure 1, the second groove 17 penetrating a portion of the winding surface 131 and a portion of the avoidance surface 141, the first groove 16 and the second groove 17 are arranged radially spaced along the winding needle structure 1.

[0099] In this embodiment, the openings of the first groove 16 and the second groove 17 are arranged opposite to each other along the radial direction of the needle winding structure 1.

[0100] In this embodiment, the first groove 16 extending along the axial direction of the needle coiling structure 1 means that the length direction of the first groove 16 is the axial direction of the needle coiling structure 1. The same applies to the second groove 17. For example, the first groove 16 extends along the axial direction of the needle coiling structure 1 to the entire first needle coil 11, and the second groove 17 extends along the axial direction of the needle coiling structure 1 to the entire second needle coil 12.

[0101] Optionally, the first groove 16 and the second groove 17 have the same dimensions.

[0102] The first groove 16 and the second groove 17 are provided so that the two clamping needles can be inserted into the first groove 16 and the second groove 17 respectively to clamp the electrode assembly 3, thereby allowing the coiling needle structure 1 to be removed from the electrode assembly 3.

[0103] This application also provides a battery production system 100, including the winding device 400 described above.

[0104] Please see Figures 2-5 This application provides a winding device 400, including a winding needle structure 1 and a driving member 2. The winding needle structure 1 includes a first winding needle 11 and a second winding needle 12 disposed opposite to each other. At least one of the first winding needle 11 and the second winding needle 12 includes a main body portion 13 and a clearance portion 14 arranged along the axial direction of the winding needle structure 1. The main body portion 13 is used to wind a positive electrode sheet, a separator, and a negative electrode sheet to form an electrode assembly 3. Both the positive electrode sheet and the negative electrode sheet include an electrode tab 31. The clearance portion 14 is configured to face the electrode tab 31. Along the radial direction of the winding needle structure 1, the clearance surface 141 of the clearance portion 14 for facing the electrode tab 31 is lower than the winding surface 131 of the main body portion 13 for winding the electrode assembly 3. The first winding needle 11 and the second winding needle 12 are both connected to the driving member 2, and the driving member 2 is used to drive the first winding needle 11 and the second winding needle 12 to rotate synchronously. Both the first coil 11 and the second coil 12 include a main body 13 and a clearance portion 14. The clearance surface 141 of the first coil 11 extends circumferentially along the coil structure 1 to the entire outer surface of the first coil 11 facing away from the second coil 12, and the clearance surface 141 of the second coil 12 extends circumferentially along the coil structure 1 to the entire outer surface of the second coil 12 facing away from the first coil 11. Along the radial direction of the coil structure 1, the recess depth of the clearance surface 141 relative to the winding surface 131 is the same at all points. One end of the winding surface 131 near the clearance surface 141 is configured to contact the root of the tab 31.

[0105] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A winding device, characterized in that, include: A coiled needle structure includes a first coiled needle and a second coiled needle disposed opposite to each other. At least one of the first coiled needle and the second coiled needle includes a main body portion and a clearance portion arranged along the axial direction of the coiled needle structure. The main body portion is used to wind a positive electrode sheet, a separator, and a negative electrode sheet to form an electrode assembly. Both the positive electrode sheet and the negative electrode sheet include tabs. The clearance portion is configured to face the tabs. Along the radial direction of the coiled needle structure, the clearance surface of the clearance portion for facing the tabs is lower than the winding surface of the main body portion for winding the electrode assembly. The driving component is connected to both the first and second winding needles, and the driving component is used to drive the first and second winding needles to rotate synchronously.

2. The winding device according to claim 1, characterized in that, Both the first and second winding needles include the main body and the clearance portion. The clearance surface of the first winding needle extends circumferentially along the winding needle structure to the entire outer surface of the first winding needle facing away from the second winding needle. The clearance surface of the second winding needle extends circumferentially along the winding needle structure to the entire outer surface of the second winding needle facing away from the first winding needle.

3. The winding device according to claim 1, characterized in that, The clearance surface includes a first end close to the winding surface and a second end away from the winding surface. Along the radial direction of the needle winding structure, the first end and the second end have the same recess depth relative to the winding surface.

4. The winding device according to claim 3, characterized in that, Along the radial direction of the needle winding structure, the recess depth of the avoidance surface relative to the winding surface is the same at all points.

5. The winding device according to claim 1, characterized in that, The first and second winding needles also include a transition portion. The main body, the transition portion, and the clearance portion are arranged and connected sequentially along the axial direction of the winding needle structure. The transition portion includes a transition surface for facing the electrode assembly. The transition surface is an inclined plane or a curved surface.

6. The winding device according to claim 1, characterized in that, The clearance portion also includes a protrusion disposed on the clearance surface and used to support the electrode tab.

7. The winding apparatus according to claim 6, characterized in that, The protrusion is a strip-shaped protrusion that extends circumferentially along the needle coil structure.

8. The winding device according to claim 6, characterized in that, The number of protrusions is multiple, and the multiple protrusions are arranged at intervals along the circumference of the needle coil structure.

9. The winding device according to claim 1, characterized in that, Along the radial direction of the needle winding structure, the recess depth of the avoidance surface relative to the winding surface is h1, and h1 satisfies: 2mm≤h1≤5mm.

10. The winding apparatus according to claim 9, characterized in that, The h1 satisfies: 2mm≤h1≤3mm.

11. The winding apparatus according to claim 1, characterized in that, The first winding needle has a first groove extending axially along the winding needle structure, the first groove penetrating a portion of the winding surface and a portion of the avoidance surface; the second winding needle has a second groove extending axially along the winding needle structure, the second groove penetrating a portion of the winding surface and a portion of the avoidance surface; the first groove and the second groove are arranged radially spaced along the winding needle structure.

12. A battery production system, characterized in that, Includes the winding device as described in any one of claims 1-11.

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