Winding needle and winding machine

Abstract

The utility model discloses a winding needle, a winding machine and a battery cell winding method. The winding needle comprises a first connecting piece; and the second connecting piece is used for being combined with the first connecting piece, the second connecting piece and the first connecting piece are coaxially arranged, and the length after the first connecting piece and the second connecting piece are combined is larger than the length of the first connecting piece or the second connecting piece. By changing the structure of the winding needle, the rigidity of the winding needle is improved, and the efficiency and quality of winding operation are improved.

Description

[0001] Cross-references

[0002] This application incorporates Chinese Patent Application No. 202210044920.8, filed on January 14, 2022, entitled “A winding needle, a winding machine, and a method for winding battery cells,” which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of batteries, and more particularly to a winding needle, a winding machine, and a method for winding battery cells. Background Technology

[0004] Lithium-ion batteries have advantages such as small size, high energy density, high power density, high cycle life, and long storage time. They are widely used in electronic devices, electric vehicles, electric toys, and electric equipment. For example, lithium-ion batteries are currently widely used in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0005] With the widespread application of lithium-ion batteries, people are paying increasing attention to the manufacturing methods of the battery cell, the power generation component of lithium-ion batteries. The most common manufacturing method for battery cells is to form them by repeatedly winding the positive electrode, negative electrode, and separator onto a winding needle. However, the size of battery cells manufactured using this method is limited by the size of the winding needle. That is, when manufacturing longer battery cells, a sufficiently long winding needle is required, but when the length of the winding needle increases, the stiffness of the winding needle often fails to meet the requirements. Therefore, there is an urgent need for a new type of winding needle to solve the above-mentioned technical problems. Summary of the Invention

[0006] This application proposes a winding needle, a winding machine, and a battery cell winding method. By changing the structure of the existing winding needle, the rigidity of the winding needle is improved, thereby improving the efficiency and quality of the winding operation.

[0007] According to a first aspect of this application, a coiling needle is provided, comprising:

[0008] A first connector; and a second connector for combining with the first connector, wherein the second connector is coaxially arranged with the first connector, and the combined length of the first connector and the second connector is greater than the length of either the first connector or the second connector.

[0009] By coaxially combining the first and second connectors to form a winding needle with a length greater than either the first or second connector, the overall rigidity of the winding needle can be increased without increasing its diameter, while maintaining the winding length. This reduces bending deformation during winding and meets the requirements for winding wide and long battery cells. Furthermore, the smaller needle diameter increases the energy density of the battery cells wound by this needle, thereby improving the efficiency and quality of the winding operation.

[0010] In some embodiments, the first connector includes two ends along its own length direction; the second connector also includes two ends along its own length direction; one end of the first connector along its length direction is combined with one end of the second connector along its length direction.

[0011] By combining the ends of the first connector and the second connector, it is convenient to set the first connector and the second connector coaxially, and it is also convenient to limit the length of the first connector and the second connector according to the length of the coil needle.

[0012] In some embodiments, one end of the first connector along its length is connected to one end of the second connector along its length by a plug-in connection.

[0013] By inserting the ends of the first connector and the second connector together, the first connector and the second connector can support each other and form a whole, thereby improving the overall rigidity of the coil needle.

[0014] In some embodiments, one end of the first connector along its length direction and one end of the second connector along its length direction are combined in a spaced-out manner.

[0015] By spacing the ends of the first and second connectors, the lengths of the first and second connectors can be further shortened while maintaining the overall length of the winding needle, thereby improving the overall rigidity of the winding needle. Furthermore, when the lengths of the first and second connectors are shortened, their diameters can be further reduced while still maintaining the overall rigidity of the winding needle, thereby increasing the energy density of the battery cell wound by the winding needle.

[0016] In some embodiments, the needle coil further includes an intermediate connector, wherein one end of the first connector along its length direction is combined with one end of the second connector along its length direction via the intermediate connector.

[0017] By using an intermediate connector to connect the ends of the first and second connectors, the first, intermediate, and second connectors form a unified whole, providing mutual support and thus improving the overall rigidity of the winding needle. When the winding is completed and the needle is unwound, the intermediate connector remains inside the battery cell, further supporting the inner ring of the cell and maintaining its structure.

[0018] In some embodiments, the intermediate connector includes a connecting rod, the two ends of which are respectively inserted into one end of the first connector along its length direction and one end of the second connector along its length direction.

[0019] By using a connecting rod to connect the ends of the first connector and the second connector, the first connector, the connecting rod, and the second connector form a whole that can support each other, which can significantly improve the overall rigidity of the coiling needle.

[0020] In some embodiments, the connecting rod is a solid rod or a hollow rod.

[0021] The connecting rod can be made solid or hollow, and can be used to connect the first and second connecting parts. Solid connecting rods have higher structural strength. If the wound electrode and separator have a wide range, solid connecting rods can be used.

[0022] In some embodiments, the intermediate connector includes a hollow sleeve, and the first connector and the second connector are respectively inserted into the hollow sleeve from both ends of the hollow sleeve.

[0023] By using a hollow sleeve to connect the first connector and the second connector, the first connector, the hollow sleeve, and the second connector form a whole that can support each other, which can significantly improve the overall rigidity of the coiling needle.

[0024] In some embodiments, the first connector and the second connector are connected within a hollow sleeve, or are spaced apart.

[0025] The first connector and the second connector can be connected together or spaced apart inside the hollow sleeve. Both can be sleeved with the hollow sleeve. The structure with the connection is stronger. If the wound electrode and the separator are wide, the structure with the connection can be used.

[0026] In some embodiments, the hollow sleeve is provided with a plurality of vent holes.

[0027] Because the first connector, the second connector, and the hollow sleeve are closely connected, the vent holes facilitate the insertion of the first connector and the second connector into the hollow sleeve, while preventing excessive pressure inside the hollow sleeve from causing deformation.

[0028] In some embodiments, the surfaces of the first connector and the second connector are provided with a coating that reduces the frictional force generated when the connector is removed from the battery cell.

[0029] By applying a coating that reduces friction, the first and second connectors can be easily removed from the cell when the winding is finished and the needle is unloaded. This prevents the electrode plates and separator in the cell from shifting, avoids core pulling, and ensures the quality of the cell.

[0030] In some embodiments, the first connector has a radial connecting hole at its other end along its length direction, and the second connector also has a radial connecting hole at its other end along its length direction. The first connector and the second connector are configured to be fixed to the winding machine through the connecting holes.

[0031] The winding machine is equipped with positioning pins or positioning screws for the corresponding connection holes. The first and second connecting parts are fixed on the winding machine through the radial connection holes, making disassembly and assembly convenient.

[0032] According to a second aspect of this application, a winding machine is provided, comprising the winding needles described in any of the above claims.

[0033] By adopting any of the above-mentioned winding needles, the increased stiffness of the winding needles allows them to withstand greater centrifugal force and makes them less prone to deflection deformation under high-speed rotation. Therefore, it can improve the acceleration, deceleration and maximum winding speed of the winding machine, increase winding efficiency and reduce production costs.

[0034] In some embodiments, the winding machine includes a needle telescopic mechanism, and a first connector and a second connector are mounted on the needle telescopic mechanism to move closer to or further away from each other under the action of the needle telescopic mechanism.

[0035] According to a third aspect of this application, a battery cell winding method is provided, comprising:

[0036] Provides electrode sheets and separators;

[0037] The electrode sheet and the separator are wound using a winding needle, wherein the winding needle is any of the winding needles described above. Attached Figure Description

[0038] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0039] Figure 1 A front view schematic diagram of a spinning needle according to some embodiments of this application is shown;

[0040] Figure 2 It shows Figure 1 A sectional view along AA in the diagram;

[0041] Figure 3 An exploded view of the winding needles according to some embodiments of this application is shown;

[0042] Figure 4 This invention illustrates a schematic diagram showing the usage state of a coiling needle according to some embodiments of this application;

[0043] Figure 5A front view schematic diagram of a spinning needle according to some embodiments of this application is shown;

[0044] Figure 6 It shows Figure 5 A sectional view along BB in the middle;

[0045] Figure 7 A front view schematic diagram of a spinning needle according to some embodiments of this application is shown;

[0046] Figure 8 It shows Figure 7 A sectional view along CC in the middle;

[0047] Figure 9 An exploded view of the winding needles according to some embodiments of this application is shown;

[0048] Figure 10 A front view schematic diagram of a connecting rod according to some embodiments of this application is shown;

[0049] Figure 11 This invention illustrates a schematic diagram showing the usage state of a coiling needle according to some embodiments of this application;

[0050] Figure 12 A front view schematic diagram of a spinning needle according to some embodiments of this application is shown;

[0051] Figure 13 It shows Figure 12 A sectional view along DD in the middle;

[0052] Figure 14 An exploded view of the winding needles according to some embodiments of this application is shown;

[0053] Figure 15 A front view schematic diagram of a hollow sleeve according to some embodiments of this application is shown;

[0054] Figure 16 This invention illustrates a schematic diagram showing the usage state of a coiling needle according to some embodiments of this application;

[0055] Figure 17 A cross-sectional schematic diagram of a coiling needle according to some embodiments of this application is shown;

[0056] Figure 18 An exploded view of the winding needles according to some embodiments of this application is shown;

[0057] Explanation of reference numerals in the attached drawings: 1. First connector; 101. First fixed end; 102. First main body; 103. First combined end; 104. First connecting hole; 2. Second connector; 201. Second fixed end; 202. Second main body; 203. Second combined end; 204. Second connecting hole; 3. Connecting rod; 301. Third combined end; 302. Third main body; 303. Fourth combined end; 304. First vent hole; 4. Hollow sleeve; 401. Fifth combined end; 402. Fourth main body; 403. Sixth combined end; 404. Second vent hole; 5. Diaphragm. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings showing multiple embodiments according to this application. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0059] 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 specific embodiments only and is not intended to limit the application; the terms "comprising," "including," "having," "containing," etc., in the description, claims, and accompanying drawings of this application are open-ended terms. Therefore, "comprising," "including," or "having" refers to, for example, a method or apparatus having one or more steps or elements, but is not limited to having only these one or more elements. 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. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0060] In the description of this application, it should be understood that the terms "center", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0061] 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.

[0062] In this application, the reference to "embodiment" means that a specific 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 throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0063] As mentioned above, it should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, components, or groups of features, integers, steps, or components. As used in this application, the singular forms "a," "an," and "the" also include the plural forms, unless the context clearly indicates otherwise.

[0064] The terms “a” and “an” used in this specification may mean one, but may also be used interchangeably with “at least one” or “one or more”. The term “about” generally means the mentioned value plus or minus 10%, or more specifically, plus or minus 5%. The term “or” used in the claims means “and / or” unless it is explicitly stated that it refers only to alternatives.

[0065] 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.

[0066] Lithium-ion batteries (referring to individual battery cells) primarily function by the movement of lithium ions between the positive and negative electrodes. Lithium-ion batteries use an intercalated lithium compound as an electrode material. Currently, the most common positive electrode materials used in lithium-ion batteries include lithium cobalt oxide (LiCoO2), lithium manganese oxide (LiMn2O4), lithium nickel oxide (LiNiO2), and lithium iron phosphate (LiFePO4). A separator is placed between the positive and negative electrodes to form a three-layer thin-film structure. This thin-film structure is generally formed into the desired cell shape by winding or stacking. For example, the three-layer thin-film structure in a cylindrical battery is wound into a cylindrical shape, while the thin-film structure in a prismatic battery is wound or stacked into a roughly cuboid shape.

[0067] The applicant discovered that the size of lithium-ion batteries manufactured using a winding method is limited by the size of the winding needles. Specifically, when manufacturing longer lithium-ion batteries, sufficiently long winding needles are required, but simply increasing the needle length often results in insufficient stiffness. To improve the stiffness of longer winding needles, the applicant increased their diameter. However, increasing the needle diameter revealed that the needles excessively occupy battery volume, thereby reducing the battery's energy density.

[0068] After extensive research, the applicant has designed a novel winding needle, comprising a first connector and a second connector. The second connector is used to combine with the first connector, and the second connector is coaxially arranged with the first connector. Furthermore, the combined length of the first and second connectors is greater than the length of either the first or second connector alone. This novel winding needle increases the needle's rigidity while extending its length, thereby improving the efficiency and quality of the winding operation. In addition, the energy density of the battery cells wound using this winding needle can be increased.

[0069] To better understand this application, the following will be combined with... Figures 1 to 18 The embodiments of this application will be described in detail.

[0070] like Figure 1 , Figure 2 , Figure 3As shown, a coiling needle according to an embodiment of this application includes a first connector 1 and a second connector 2. The second connector 2 is used to combine with the first connector 1. The second connector 2 is coaxially arranged with the first connector 1, and the length of the combination of the first connector 1 and the second connector 2 is greater than the length of the first connector 1 or the second connector 2.

[0071] By coaxially combining the first connector 1 and the second connector 2 to form a winding needle with a length greater than either the first connector 1 or the second connector 2, the overall rigidity of the winding needle can be increased without increasing its diameter, while ensuring the winding length. This reduces bending deformation during winding and meets the requirements for winding wide and long battery cells. Furthermore, the smaller diameter of the winding needle increases the energy density of the battery cell wound by it, thereby improving the efficiency and quality of the winding operation.

[0072] In some embodiments, such as Figure 1 , Figure 2 As shown, the first connector 1 includes two ends along its own length direction; the second connector 2 also includes two ends along its own length direction; one end of the first connector 1 along its length direction is combined with one end of the second connector 2 along its length direction.

[0073] By combining the ends of the first connector 1 and the second connector 2, it is convenient to set the first connector 1 and the second connector 2 coaxially, and it is also convenient to define the ratio of the length of the first connector 1 and the second connector 2 to the overall length of the coiling needle.

[0074] like Figure 3 , Figure 4 As shown, the first connector 1 includes a first combined end 103, a first main body portion 102, and a first fixed end 101, and the second connector 2 includes a second combined end 203, a second main body portion 202, and a second fixed end 201. The portion of the first connector 1 that winds the battery cell is the first main body portion 102, and the portion of the second connector 2 that winds the battery cell is the second main body portion 202. The cross-sections of the first main body portion 102 and the second main body portion 202 are: circular, elliptical, polygonal with more than three sides, polygonal with rounded corners, or flat.

[0075] The materials of the first connector 1 and the second connector 2 are not limited to commonly used carbon steel, carbon structural steel, high-quality structural steel, carbon tool steel, free-cutting structural steel, alloy steel, ordinary low alloy steel, alloy steel for engineering structures, alloy steel for mechanical structures, alloy structural steel, alloy tool steel, high-speed tool steel, etc.

[0076] In some embodiments, such as Figure 1 , Figure 2As shown, one end of the first connector 1 along its length is connected to one end of the second connector 2 along its length by an insertion method. The state of the winding needle winding the electrode sheet and the separator in this embodiment is as follows: Figure 4 As shown, Figure 4 The membrane 5 in the middle includes a positive electrode, a negative electrode, and a separator.

[0077] By inserting the ends of the first connector 1 and the second connector 2 together, the first connector 1 and the second connector 2 can support each other and form a whole, thereby improving the overall rigidity of the coil needle.

[0078] The first assembly end 103 of the first connector 1 is provided with a conical, cylindrical, or polygonal slot, and the second assembly end 203 of the second connector 2 is correspondingly provided with a conical, cylindrical, or polygonal plug. This plug-in structure facilitates the coaxiality of the first connector 1 and the second connector 2.

[0079] In some embodiments, such as Figure 5 , Figure 6 As shown, one end of the first connector 1 along its length direction and one end of the second connector 2 along its length direction are combined by means of spacing.

[0080] By spacing the ends of the first connector 1 and the second connector 2, the lengths of the first connector 1 and the second connector 2 can be further shortened, thereby improving the overall rigidity of the coil needle. The diameters of the first connector 1 and the second connector 2 can also be further reduced, thereby increasing the energy density of the battery cell.

[0081] In some embodiments, the needle coil further includes an intermediate connector, wherein one end of the first connector 1 along its length direction is combined with one end of the second connector 2 along its length direction via the intermediate connector.

[0082] By using an intermediate connector to connect the ends of the first connector 1 and the second connector 2, the first connector 1, the intermediate connector, and the second connector 2 form a whole that can support each other, thereby improving the overall rigidity of the coiling needle.

[0083] When the winding is completed and the pins are unloaded, the intermediate connector remains inside the cell, providing support for the inner ring and maintaining the cell's structure. The intermediate connector is made of plastic and its presence inside the cell does not affect its electrical performance.

[0084] In some embodiments, such as Figure 7 , Figure 8 , Figure 9 , Figure 10As shown, the intermediate connecting member includes a connecting rod 3. The two ends of the connecting rod 3 are respectively inserted into one end of the first connecting member 1 along its length direction and one end of the second connecting member 2 along its length direction. The state of the winding needle winding the pole piece and the separator film in this embodiment is as Figure 11 shown, Figure 11 The diaphragm 5 in

[0085] includes a positive pole piece, a negative pole piece and a separator film. By using the connecting rod 3 to connect the ends of the first connecting member 1 and the second connecting member 2, the first connecting member 1, the connecting rod 3 and the second connecting member 2 form an integral whole, can support each other, and can significantly improve the overall stiffness of the winding needle.

[0086] As Figure 9 , Figure 10 shown, the connecting rod 3 includes a third combined end 301, a third main body 302, and a fourth combined end 303. The third combined end 301 is inserted into the first combined end 103 of the first connecting member 1, and the fourth combined end 303 is inserted into the second combined end 203 of the second connecting member 2. At this time, the main parts of the wound battery cell are the second main body 202, the third main body 302, and the first main body 102.

[0087] A coating for increasing the friction force can be provided on the outer wall of the connecting rod 3. By providing the coating that can increase the friction force, the friction force between the connecting rod 3 and the diaphragm 5 can be increased, which is convenient for winding and can also stably hold the connecting rod 3 inside the battery cell.

[0088] For the convenience of insertion, the first combined end 103 and the second combined end 203 are respectively provided with a "convex" - shaped connection structure. Correspondingly, the two ends of the connecting rod 3 are respectively provided with a "concave" - shaped connection structure. Through the setting of this insertion structure, it is convenient for the first connecting member 1, the connecting rod 3 and the second connecting member 2 to be coaxial.

[0089] The material of the connecting rod 3 is plastic, and remaining in the battery cell will not affect the electrical performance of the battery cell.

[0090] In some embodiments, the connecting rod 3 is a solid rod or a hollow rod. Figure 9 The shown connecting rod 3 is a hollow rod.

[0091] Setting the connecting rod 3 as solid or hollow can both connect the first connecting member 1 and the second connecting member 2. The solid connecting rod 3 has higher structural strength. If the width of the wound pole piece and the separator film is relatively wide, a solid connecting rod 3 can be used.

[0092] In some embodiments, a number of first ventilation holes 304 are provided on the hollow connecting rod 3.

[0093] Because the first connector 1, the second connector 2 and the connecting rod 3 are closely connected, by setting vent holes, it is convenient for the first connector 1 and the second connector 2 to be inserted into the connecting rod 3, while avoiding excessive internal pressure and deformation of the connecting rod 3.

[0094] In some embodiments, such as Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown, the intermediate connector includes a hollow sleeve 4, with the first connector 1 and the second connector 2 inserted into the hollow sleeve 4 from both ends, respectively. The state of the winding needle winding the electrode sheet and the separator in this embodiment is as follows... Figure 16 As shown, Figure 16 The membrane 5 in the middle includes a positive electrode, a negative electrode, and a separator.

[0095] By using a hollow sleeve 4 to connect the first connector 1 and the second connector 2, the first connector 1, the hollow sleeve 4 and the second connector 2 form a whole that can support each other, which can significantly improve the overall rigidity of the coiling needle.

[0096] like Figure 14 , Figure 15 As shown, the hollow sleeve 4 includes a fifth assembly end 401, a fourth main body portion 402, and a sixth assembly end 403. At this time, the part where the battery cell is wound is mainly the fourth main body portion 402.

[0097] A coating can be provided on the inner wall of the hollow sleeve 4 to reduce the friction generated when the first connector 1 and the second connector 2 are withdrawn. By providing a coating that reduces friction, the first connector 1 and the second connector 2 can be easily withdrawn from the hollow sleeve 4 when the winding is finished and the needle is unloaded, without causing the hollow sleeve 4 to shift. This also prevents the electrode plates and separator in the core from shifting, avoiding core pulling and ensuring the quality of the battery cell.

[0098] A coating that increases friction can also be provided on the outer wall of the hollow sleeve 4. By providing a coating that increases friction, the friction between the hollow sleeve 4 and the diaphragm 5 can be increased, which not only facilitates winding but also keeps the hollow sleeve 4 stably inside the cell.

[0099] In some embodiments, the first connector 1 and the second connector 2 are connected within the hollow sleeve 4, or are spaced apart. For example... Figure 12 , Figure 13 , Figure 14 The first connector 1 and the second connector 2 are connected inside the hollow sleeve 4, as shown. Figure 17 , Figure 18 The first connector 1 and the second connector 2 shown are spaced apart inside the hollow sleeve 4.

[0100] The first connector 1 and the second connector 2 can be connected together or spaced apart inside the hollow sleeve 4, and can be sleeved with the hollow sleeve 4. The structure of connection is stronger. If the width of the wound electrode and the separator is wide, the structure of connection can be adopted.

[0101] In some embodiments, the hollow sleeve 4 is provided with a plurality of second vent holes 404.

[0102] Because the first connector 1, the second connector 2 and the hollow sleeve 4 are closely connected, by setting vent holes, it is convenient for the first connector 1 and the second connector 2 to be inserted into the hollow sleeve 4, while avoiding excessive pressure inside the hollow sleeve 4 and deformation.

[0103] The hollow sleeve 4 is made of plastic and remains inside the battery cell without affecting the battery cell's electrical performance.

[0104] In some embodiments, the surfaces of the first connector 1 and the second connector 2 are provided with a coating to reduce the friction generated when the battery is extracted from the cell.

[0105] By setting a coating that reduces friction, the first connector 1 and the second connector 2 can be easily pulled out from the cell when the winding is finished and the needle is unloaded, which will not cause the electrode and separator in the cell to shift, thus avoiding core pulling and ensuring the quality of the cell.

[0106] In some embodiments, such as Figure 3 As shown, the first connector 1 has a radial connecting hole 104 at its other end along its length direction, and the second connector 2 also has a radial connecting hole 204 at its other end along its length direction. The first connector 1 and the second connector 2 are configured to be fixed to the winding machine through the connecting holes.

[0107] The winding machine is equipped with positioning pins or positioning screws for the corresponding connection holes. The first connecting piece 1 and the second connecting piece 2 are fixed on the winding machine through the radial connection holes, making disassembly and assembly convenient.

[0108] According to a second aspect of this application, a winding machine is provided, comprising the winding needles described in any of the above claims.

[0109] By adopting any of the above-mentioned winding needles, the increased stiffness of the winding needles allows them to withstand greater centrifugal force and makes them less prone to deflection deformation under high-speed rotation. Therefore, it can improve the acceleration, deceleration and maximum winding speed of the winding machine, increase winding efficiency and reduce production costs.

[0110] In some embodiments, the winding machine includes a needle telescopic mechanism, and a first connector 1 and a second connector 2 are mounted on the needle telescopic mechanism to move closer to or further away from each other under the drive of the needle telescopic mechanism.

[0111] In some embodiments, a diaphragm pressure roller and a hook knife are provided on the winding machine corresponding to the winding needle. The diaphragm pressure roller and the hook knife can move closer to and further away from the winding needle under the drive of the drive mechanism. When the electrode and the separator begin to be wound, firstly, the diaphragm pressure roller moves closer to the winding needle, pressing the electrode and the separator against the winding needle; secondly, the hook knife hooks the ends of the electrode and the separator, so that their ends are wound on the winding needle; then, the winding needle winds at a small angle, using the electrode and the separator themselves to press their ends; finally, the hook knife and the diaphragm pressure roller move away from the winding needle in sequence, and the winding needle rotates normally, winding the electrode and the separator into a battery cell.

[0112] According to a third aspect of this application, a battery cell winding method is provided, comprising:

[0113] Provides electrode sheets and separators;

[0114] The electrode sheet and the separator are wound using a winding needle, wherein the winding needle is any of the winding needles described above.

[0115] 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 needle for winding a battery cell, characterized in that: include: a first connecting member; and, a second connecting member, used to be combined with the first connecting member, the second connecting member is coaxially arranged with the first connecting member, and the length of the first connecting member and the second connecting member after being combined is greater than the length of the first connecting member or the second connecting member, Among them, the first connecting member includes two ends along its own length direction; the second connecting member also includes two ends along its own length direction; one end of the first connecting member along its length direction and one end of the second connecting member along its length direction are combined in a spaced manner.

2. The winding needle according to claim 1, characterized in that: The winding needle further includes an intermediate connecting piece, and one end of the first connecting piece along the length direction thereof is combined with one end of the second connecting piece along the length direction thereof through the intermediate connecting piece.

3. The winding needle according to claim 2, characterized in that: The intermediate connecting member comprises a connecting rod, and two ends of the connecting rod are respectively plugged into one end of the first connecting member along the length direction thereof and one end of the second connecting member along the length direction thereof.

4. The winding needle according to claim 3, characterized in that: The connecting rod is a solid rod or a hollow rod.

5. The winding needle according to claim 2, characterized in that: The intermediate connecting member includes a hollow sleeve, and the first connecting member and the second connecting member are respectively inserted into the hollow sleeve from both ends of the hollow sleeve.

6. The winding needle according to claim 5, characterized in that: The first connecting member and the second connecting member are spaced apart in the hollow sleeve.

7. The winding needle according to claim 5 or 6, characterized in that: The hollow sleeve is provided with a plurality of air holes.

8. The winding needle according to any one of claims 1 to 6, characterized in that The surfaces of the first connecting member and the second connecting member are provided with a coating which reduces the friction force generated when the first connecting member is pulled out from the battery core.

9. The winding needle according to any one of claims 2 to 6, characterized in that The first connecting member is provided with a radial connecting hole at the other end along its length direction, and the second connecting member is also provided with a radial connecting hole at the other end along its length direction. The first connecting member and the second connecting member are configured to be fixed to the winding machine through the connecting holes.

10. A winding machine, characterized in that: The invention comprises the winding needle according to any one of claims 1 to 9.

11. The winding machine according to claim 10, characterized in that The winding machine comprises a winding needle telescopic mechanism, and the first connecting member and the second connecting member are mounted on the winding needle telescopic mechanism so as to approach or move away from each other under the drive of the winding needle telescopic mechanism.

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