Winding needle, winding equipment and battery processing system

Abstract

The utility model is suitable for the technical field of power battery manufacturing, and provides a winding needle, winding equipment and a battery processing system, the winding needle is used for winding an electrode assembly, the winding needle comprises two end faces, and the two end faces are arranged at intervals in the axial direction of the winding needle; the winding needle further comprises at least three outer side faces which are sequentially connected end to end in the circumferential direction of the winding needle, the outer side faces are used for abutting against the electrode assembly, and the two ends, in the axial direction of the winding needle, of the outer side faces are connected to the two end faces respectively. The winding needle provided by the utility model comprises three or more outer side surfaces, so that an edge can be formed at the intersection of two adjacent outer side surfaces, and in the process of winding the electrode assembly on the winding needle, the arrangement can increase the distance between the pole piece on the outer side and the pole piece on the inner side at the edge, so that the winding needle can be used for winding the electrode assembly on the winding needle. Therefore, after the electrode assembly is shaped, a larger pole piece gap can be formed at the corner, so that more electrolyte can enter the corner of the electrode assembly, and the effect of prolonging the service life of the battery is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of power battery manufacturing, and in particular to a winding needle, winding equipment and a battery processing system. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automobile industry. Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development.

[0003] In the battery production process, the winding of the electrode assembly is a very important process, and the electrode assembly needs to be wound on the winding needle of the winding equipment. At present, after the electrode assembly is unloaded from the winding needle, the shaping process will cause the shape of the electrode assembly to change, and the gap between adjacent pole pieces at the corners of the electrode assembly will be smaller, which will easily lead to insufficient electrolyte entering the electrode assembly at the corners, which will easily have a negative impact on the life of the battery. Utility Model Content

[0004] In view of the above problems, the present application provides a winding needle, a winding device and a battery processing system, which can alleviate the problem of small gap between pole pieces at the corners after the electrode assembly is shaped, which affects the battery life.

[0005] In a first aspect, the present application provides a winding needle for winding an electrode assembly, wherein the winding needle includes two end surfaces, and the two end surfaces are arranged at intervals along the axial direction of the winding needle;

[0006] The winding needle also includes at least three outer side surfaces which are connected in sequence along the circumferential direction of the winding needle. The outer side surfaces are used to abut against the electrode assembly. Both ends of the outer side surfaces along the axial direction of the winding needle are respectively connected to the two end surfaces.

[0007] In the technical solution of this embodiment, the winding needle includes three or more outer side surfaces so that two adjacent outer side surfaces can form an edge at the intersection. During the process of winding the electrode assembly on the winding needle, this arrangement can increase the distance between the outer electrode sheet and the inner electrode sheet at the edge, so that the electrode assembly can have a larger electrode sheet gap at the corner after shaping, thereby allowing more electrolyte to enter the corner of the electrode assembly, thereby improving the battery life.

[0008] In some embodiments, the outer side has three;

[0009] Two adjacent outer side surfaces intersect to form a first side, the outer side surface intersects with the end surface to form a second side, and the second side is formed between the two first sides and intersects with both first sides;

[0010] The three second sides form a triangle.

[0011] In the technical solution of this embodiment, there are three outer side surfaces, and the winding needle can be a triangular prism or a quasi-triangular prism structure. As the number of outer side surfaces increases, the shape of the winding needle will gradually approach a cylindrical shape, and will cause the pole piece gap of the electrode assembly to gradually decrease. Therefore, having three outer side surfaces of the winding needle can make the pole piece gap of the electrode assembly at the corners larger.

[0012] In some embodiments, the ratio of the lengths of any two of the three second sides of the three outer side surfaces ranges from 0.1 to 10.

[0013] The technical solution of this embodiment provides some dimensional relationships between the three outer side surfaces, so that the ratio of the lengths of the second sides of any two outer side surfaces is in the range of 0.1 to 10. This setting can not only reduce the wear of the electrode assembly at the edge of the winding needle during the winding process, but also increase the pole piece gap of the electrode assembly at the edge of the winding needle.

[0014] In some embodiments, at least two of the three second sides of the three outer sides are equal in length.

[0015] The technical solution of this embodiment further provides some dimensional relationships between the three outer side surfaces so that the winding needle is an isosceles triangular prism; this setting can not only further reduce the wear of the electrode assembly at the edge of the winding needle during the winding process, but also increase the pole piece gap of the electrode assembly at the edge of the winding needle.

[0016] In some embodiments, the lengths of the three second sides of the three outer sides are all equal.

[0017] The technical solution of this embodiment further provides some dimensional relationships between the three outer side surfaces so that the winding needle is a regular triangular prism; this setting can not only further reduce the wear of the electrode assembly at the edge of the winding needle during the winding process, but also increase the pole piece gap of the electrode assembly at the edge of the winding needle.

[0018] In some embodiments, the outer side has four;

[0019] Two adjacent outer side surfaces intersect to form a third side, the outer side surface and the end surface intersect to form a fourth side, and the fourth side is formed between the two third sides and intersects with both third sides;

[0020] The four fourth sides form a quadrilateral.

[0021] In the technical solution of this embodiment, there are four outer side surfaces, and the winding needle can be a quadrangular prism or a quasi-quadrangular prism structure. As the number of outer side surfaces increases, the shape of the winding needle will gradually approach a cylindrical shape, and will cause the pole piece gap of the electrode assembly to gradually decrease. Therefore, having four outer side surfaces of the winding needle can not only make the pole piece gap of the electrode assembly at the corners larger, but also reduce the damage to the pole piece at the edge of the winding needle due to excessive bending angles.

[0022] In some embodiments, the winding needle includes at least two sub-needle bodies spliced ​​together;

[0023] The winding needle also includes an inner needle, which is arranged between at least two sub-needle bodies and is detachably connected to the sub-needle bodies.

[0024] In the technical solution of this embodiment, the winding needle includes at least two sub-needle bodies, and the sub-needle bodies are detachably connected to the inner needle, so that the external driving structure drives the sub-needle bodies to rotate synchronously through the inner needle, thereby driving the entire winding needle to rotate to wind the electrode assembly; the winding needle includes at least two sub-needle bodies, which also facilitates the installation, disassembly and replacement of the inner needle.

[0025] In some embodiments, a receiving groove is provided on the sub-needle body, and the receiving groove is used to receive at least a portion of the inner needle.

[0026] In the technical solution of this embodiment, a receiving groove is provided on the sub-needle body to accommodate the inner needle through the receiving groove; because the inner needle is provided between the two sub-needle bodies, it is easy to cause a larger distance between the two sub-needle bodies, and this distance is too large to easily cause the electrode assembly to deform at this distance during the winding process. Providing a receiving groove on the sub-needle body and accommodating at least part of the inner needle in the receiving groove can reduce the distance between the two sub-needle bodies, thereby reducing the negative impact of the distance on the winding of the electrode assembly.

[0027] In some embodiments, a fixing hole is provided on the sub-needle body, and one end of the fixing hole is connected to the receiving groove;

[0028] The winding needle also includes a fixing piece detachably connected to the sub-needle body, one end of the fixing piece is accommodated in the fixing hole, and the other end abuts against the inner needle.

[0029] The technical solution of this embodiment provides some specific structures for connecting the inner needle and the sub-needle body. A fixing hole connected to the accommodating groove is provided on the sub-needle body, so that one end of the fixing part can abut against the inner needle to fix the inner needle in the accommodating groove, and the other end of the fixing part is accommodated in the fixing hole, so as to reduce the interference of the fixing part extending beyond the winding needle with the winding of the electrode assembly.

[0030] In some embodiments, at least two sub-needle bodies are spaced apart and a clamping space is formed between the two sub-needle bodies, and the clamping space is used to accommodate a portion of the electrode assembly;

[0031] At least one of the two sub-needle bodies on both sides of the clamping space can move relative to the other so as to approach or move away from the other.

[0032] In the technical solution of this embodiment, a clamping space is provided between the two sub-needle bodies so that part of the electrode assembly can be accommodated in the clamping space; at least one of the two sub-needle bodies is enabled to move closer to or away from the other so that the two sub-needle bodies can clamp part of the electrode assembly in the clamping space, thereby fixing the end of the electrode assembly and facilitating the winding of the electrode assembly on the winding needle.

[0033] In some embodiments, an air suction channel is provided inside the sub-needle body, and an adsorption hole with one end connected to the air suction channel is provided on the outer surface.

[0034] In the technical solution of this embodiment, an exhaust channel is arranged in the sub-needle body, and an adsorption hole connected with the exhaust channel is arranged on the sub-needle body, so that the winding needle can adsorb and fix part of the electrode assembly on the winding needle by exhausting air from the exhaust channel to the outside of the winding needle, thereby achieving the fixation of the end of the electrode assembly and facilitating the winding of the electrode assembly on the winding needle.

[0035] In some embodiments, a feed slot extending in the radial direction of the winding needle is also provided on the outer surface;

[0036] In the radial direction of the winding needle, at least one end of the material discharge groove is communicated with the space outside the winding needle.

[0037] In the technical solution of this embodiment, a material unloading groove is provided on the sub-needle body, so that the unloading equipment can extend into the wound electrode assembly and remove the electrode assembly from the winding needle.

[0038] In some embodiments, an air extraction channel is provided inside the winding needle, and an adsorption hole with one end connected to the air extraction channel is provided on the outer surface.

[0039] In the technical solution of this embodiment, an exhaust channel is provided inside the winding needle, and an adsorption hole connected to the exhaust channel is provided on the outer surface, so that the winding needle can adsorb and fix part of the electrode assembly on the winding needle by exhausting air from the exhaust channel to the outside of the winding needle, thereby achieving fixation of the end of the electrode assembly and facilitating winding of the electrode assembly on the winding needle.

[0040] In a second aspect, some embodiments of the present application further provide a winding device, comprising the winding needle provided by some embodiments of the first aspect.

[0041] In a third aspect, some embodiments of the present application further provide a battery processing system, comprising the winding device provided by some embodiments of the second aspect.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0044] Figure 1 A schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application;

[0045] Figure 2 A three-dimensional schematic diagram of a winding needle provided in some embodiments of the present application;

[0046] Figure 3 A schematic front view of a winding needle provided in some embodiments of the present application;

[0047] Figure 4 A schematic side view of a winding needle provided in some embodiments of the present application;

[0048] Figure 5 A schematic diagram of the dimensional relationship of a needle-wound electrode assembly provided in some embodiments of the present application;

[0049] Figure 6 A schematic diagram of the dimensional relationship of the electrode assembly after it is removed from the winding needle provided in some embodiments of the present application and reshaped;

[0050] Figure 7 A schematic diagram of the dimensional relationship of the current needle-wound electrode assembly;

[0051] Figure 8 A schematic diagram of the dimensional relationship of the electrode assembly after it is removed from the current winding needle and reshaped;

[0052] Fig. 9 A three-dimensional schematic diagram of a winding needle provided in some other embodiments of the present application;

[0053] Fig.10 A three-dimensional schematic diagram of a rolled needle neutron needle body provided in some embodiments of the present application;

[0054] Fig.11 A schematic front view of a rolled needle neutron needle body provided in some embodiments of the present application;

[0055] Fig.12 A schematic side view of a coiled needle neutron needle body provided in some embodiments of the present application;

[0056] Fig.13 for Figure 4 Schematic cross-sectional view at AA in the middle.

[0057] Fig.14 A three-dimensional schematic diagram of a rolled needle neutron needle body provided in some embodiments of the present application.

[0058] The meanings of the marks in the figure are:

[0059] 100, rolling needle;

[0060] 101, outer side; 1011, first side; 1012, second side; 1013, third side; 1014, fourth side; 102, end face;

[0061] 10. Sub-needle body; 11. Accommodation slot; 12. Fixing hole; 13. Feeding slot;

[0062] 20. Internal needle;

[0063] 30. Fixing parts;

[0064] 40. Clamping space;

[0065] 51. adsorption hole; 52. air extraction channel;

[0066] 200. Electrode assembly;

[0067] 61. First pole piece; 62. Second pole piece; 63. Diaphragm. DETAILED DESCRIPTION

[0068] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0070] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0071] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0072] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0073] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0074] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0075] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0076] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0077] The electrode assembly is the main component of the battery where the electrochemical reaction occurs. The electrode assembly is mainly formed by winding the first pole piece, the second pole piece and the diaphragm, so the winding of the electrode assembly is a very important process in the battery production process.

[0078] During the battery production process, the first electrode sheet, the second electrode sheet and the separator are usually wound on a winding needle of a winding device and combined to form an electrode assembly. The wound electrode assembly usually needs to undergo a shaping process after being removed from the winding needle.

[0079] Currently, winding needles are mostly cylindrical. When the first pole piece, the second pole piece and the diaphragm are wound on the winding needle, the gaps between the pole pieces at each position are relatively uniform and roughly equal, which easily leads to smaller pole piece gaps at the corners of the electrode assembly after shaping. The smaller pole piece gap of the electrode assembly easily leads to less electrolyte at the corresponding position, because the electrolyte will be continuously consumed as the battery is used. The smaller pole piece gap of the electrode assembly will also aggravate the situation of local electrolyte shortage as the battery is used, thereby shortening the battery life.

[0080] In order to alleviate the problem that the gap between the electrode sheets at the corners is small after the electrode assembly is shaped, which affects the battery life, the gap between the electrode sheets at the corners of the electrode assembly can be increased to accommodate more electrolyte. Accordingly, the present application provides a winding needle, which includes at least three outer side surfaces connected in sequence along the circumference of the winding needle, and the electrode assembly is wound on the outer side surface during the winding process.

[0081] In such a winding needle, two adjacent outer side surfaces can form an edge at the intersection. When the electrode assembly is wound on such a winding needle, the pole piece gap at the position corresponding to the edge of the electrode assembly will become larger. Because the edge is formed by the intersection of two adjacent outer side surfaces, the larger the angle between the two outer side surfaces, the larger the pole piece gap at the position corresponding to the edge of the electrode assembly. Therefore, the pole piece gap at the corner of the electrode assembly can be increased after shaping, so that more electrolyte can enter the corner of the electrode assembly and extend the life of the motor.

[0082] The winding device provided in the embodiment of the present application can be wound to form a cylindrical electrode assembly, or it can be wound to form a prismatic electrode assembly or an electrode assembly of other shapes. The electrode assembly formed by the winding device can be used as a component for electrochemical reaction in a battery cell, and the battery cell can be used in an electrical device that uses a battery as a power source or various energy storage systems that use a battery as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys, electric airplane toys, and the like, and the spacecraft can include airplanes, rockets, space shuttles, spacecrafts, and the like.

[0083] For the convenience of explanation, the following embodiments are described by taking a winding device according to some embodiments of the present application for forming a prismatic electrode assembly as an example.

[0084] refer to Figure 1 , Figure 1 A schematic diagram of the structure of an electrode assembly 200 provided for some embodiments of the present application. The electrode assembly 200 is a component in a battery cell where an electrochemical reaction occurs. A battery cell may include one, two or more electrode assemblies 200. The electrode assembly 200 is mainly formed by winding a first pole piece 61 and a second pole piece 62, and a diaphragm 63 is usually provided between the first pole piece 61 and the second pole piece 62. The polarities of the first pole piece 61 and the second pole piece 62 are different. For example, the first pole piece 61 may be a positive pole piece, in which case the second pole piece 62 is a negative pole piece; the first pole piece 61 may also be a negative pole piece, in which case the second pole piece 62 is a positive pole piece. The parts of the first pole piece 61 and the second pole piece 62 having active materials constitute the main body of the electrode assembly 200, and the parts of the first pole piece 61 and the second pole piece 62 not having active materials each constitute a pole ear. The pole ear of the first pole piece 61 and the pole ear of the second pole piece 62 may be located at one end of the main body or at both ends of the main body respectively. During the charge and discharge process of the battery, the active material of the first electrode sheet 61 and the active material of the second electrode sheet 62 react with the electrolyte, and the electrode tabs are connected to the electrode terminals to form a current loop.

[0085] First, refer to Figures 2 to 4 , Fig. 9 Some embodiments of the present application provide a winding needle 100 for winding an electrode assembly 200. The winding needle 100 includes two end surfaces 102. The two end surfaces 102 are arranged at intervals along the axial direction of the winding needle 100. The winding needle 100 also includes at least three outer side surfaces 101 connected in sequence end to end along the circumferential direction of the winding needle 100. The outer side surfaces 101 are used to abut the electrode assembly 200. The two ends of the outer side surfaces 101 along the axial direction of the winding needle 100 are respectively connected to the two end surfaces 102.

[0086] Figure 2 In the figure, the axial direction of the winding needle 100 is the direction where the X-axis is located; the radial direction of the winding needle 100 is the direction perpendicular to the axial direction (X), and the radial direction of the winding needle 100 is also the direction parallel to the plane where the Y-axis and the Z-axis are located; the circumferential direction of the winding needle 100 is the direction around the X-axis with the direction where the X-axis is located as the axis.

[0087] The outer side surface 101 of the winding needle 100 refers to the surface located on the circumferential side of the winding needle 100 and facing the outside. During the process of winding the electrode assembly 200 onto the winding needle 100, the electrode assembly 200 contacts the outer side surface 101 of the winding needle 100 and is wound on each outer side surface 101; the outer side surface 101 can be a plane or a curved surface, and can be a quadrilateral, a pentagon or other shapes.

[0088] There are at least three outer side surfaces 101, that is, there can be three, four, five or more outer side surfaces 101; at least three outer side surfaces 101 are connected in sequence along the circumference of the winding needle 100, and the head and tail of the outer side surfaces 101 refer to the two sides of the outer side surfaces 101 in the circumferential direction of the winding needle 100; for example, along the circumference of the winding needle 100, one side of an outer side surface 101 is connected to the adjacent side of another adjacent outer side surface 101.

[0089] The outer side surface 101 may be parallel to the axial direction of the winding needle 100 , in which case the winding needle 100 may be a columnar structure; the outer side surface 101 may also be non-parallel to the axial direction of the winding needle 100 , in which case the winding needle 100 may be a terraced structure.

[0090] The end face 102 refers to the surface located at both ends of the winding needle 100 and facing the outside. The end face 102 is located at both ends of the winding needle 100 along the axial direction of the winding needle 100. During the process of winding the electrode assembly 200 onto the winding needle 100, the end face 102 of the winding needle 100 usually does not contact the electrode assembly 200; the end face 102 can be a flat surface or a curved surface.

[0091] The two end faces 102 are connected to the opposite ends of the outer side surface 101 along the axial direction of the winding needle 100, that is, the end face 102 is connected to each outer side surface 101; accordingly, the shape of the end face 102 can be set according to the number of outer side surfaces 101. For example, when there are five outer side surfaces 101, the end face 102 can be a pentagon.

[0092] For example, the outer side surface 101 is a rectangular plane and there are three of them, each outer side surface 101 is parallel to the axial direction of the winding needle 100, and the end surface 102 is a triangular plane. In this case, the winding needle 100 is a three-sided right prism structure.

[0093] For example, the outer side surface 101 is a parallelogram plane and there are four of them, each outer side surface 101 is parallel to the axial direction of the winding needle 100, and the end surface 102 is a rectangular plane. In this case, the winding needle 100 is a four-sided oblique prism structure.

[0094] For example, the outer side surface 101 is a rectangular plane and there are five of them, each outer side surface 101 is not parallel to the axial direction of the winding needle 100, and the end surface 102 is a pentagonal plane. In this case, the winding needle 100 is a pentagonal pyramid-shaped structure.

[0095] When the electrode assembly 200 is wound on the cylindrical winding needle 100, since the distance from any position on the side of the cylindrical winding needle 100 to the axis of the winding needle 100 is equal or approximately equal (the distance is the radius of the winding needle 100), during the winding process of the electrode assembly 200, the spacing between the first pole piece 61 and the adjacent second pole piece 62 is always equal or approximately equal; after such an electrode assembly 200 is removed from the winding needle 100 and shaped, the gap between the first pole piece 61 and the adjacent second pole piece 62 of the shaped electrode assembly 200 at the corner is smaller.

[0096] In the winding needle 100 provided in the present embodiment, an edge is formed at the intersection of two adjacent outer side surfaces 101, which results in different distances between various positions on the circumferential side of the winding needle 100 and the axis of the winding needle 100; when the electrode assembly 200 is wound on the winding needle 100 provided in the present embodiment, the spacing between the first pole piece 61 and the adjacent second pole piece 62 in the electrode assembly 200 is the largest at the edge. After such an electrode assembly 200 is removed from the winding needle 100 and shaped, the gap between the first pole piece 61 and the adjacent second pole piece 62 of the shaped electrode assembly 200 at the corner is larger.

[0097] In this embodiment, the winding needle 100 includes three or more outer side surfaces 101, so that two adjacent outer side surfaces 101 can form an edge at the intersection. When the electrode assembly 200 is wound on the winding needle 100, this arrangement can increase the distance between the first pole piece 61 and the adjacent second pole piece 62 at the edge, so that the electrode assembly 200 can have a larger pole piece gap at the corner after shaping, thereby allowing more electrolyte to enter the corner of the electrode assembly 200 and improving the battery life.

[0098] refer to Figures 2 to 4 In some embodiments, there are three outer side surfaces 101; two adjacent outer side surfaces 101 intersect to form a first side 1011, the outer side surface 101 intersects with the end surface 102 to form a second side 1012, and the second side 1012 is formed between the two first sides 1011 and intersects with both first sides 1011; the three second sides 1012 form a triangle.

[0099] The first side 1011 refers to the side formed by the intersection of two adjacent outer side surfaces 101, that is, the outer side surface 101 intersects with another adjacent outer side surface 101 at the first side 1011, and can enable the winding needle 100 to form an edge at the first side 1011; in the same outer side surface 101, there are two first sides 1011 and they are arranged opposite to each other along the circumference of the winding needle 100, and the two first sides 1011 of the same outer side surface 101 are respectively formed by the outer side surface 101 and the outer side surfaces 101 on the adjacent two sides intersecting; the two first sides 1011 can be parallel to each other, or they can be non-parallel to each other and intersect on the extension lines of the two.

[0100] For example, two adjacent outer side surfaces 101 are connected at their first edges 1011 , and at this time, the first edges 1011 of the two outer side surfaces 101 overlap and form an edge of the winding needle 100 .

[0101] The second side 1012 refers to the side formed by the intersection of the outer side surface 101 and the end surface 102, that is, the outer side surface 101 is connected to the end surface 102 at the second side 1012; on the same outer side surface 101, there are two second sides 1012 and the two second sides 1012 are arranged opposite to each other along the axial direction of the winding needle 100; the two second sides 1012 can be parallel to each other, or they can be non-parallel to each other and intersect on the extension line of the two second sides 1012; the second side 1012 is also formed between the two first sides 1011 and intersects with both first sides 1011, the second side 1012 can be perpendicular to the first side 1011, or it can be arranged at other angles with the first side 1011.

[0102] The three second sides 1012 can form a triangle. In this case, the winding needle 100 can be a triangular prism, a triangular pyramid, or a structure with three edges on the circumference.

[0103] For example, two first sides 1011 of the same outer side surface 101 are parallel to each other, and two second sides 1012 of the same outer side surface 101 are parallel to each other, and the second sides 1012 are perpendicular to the two first sides 1011. In this case, the outer side surface 101 is a rectangle, and the winding needle 100 is a triangular prism.

[0104] In this embodiment, there are three outer side surfaces 101, and the winding needle 100 can be a triangular prism or a triangular prism-like structure. As the number of outer side surfaces 101 increases, the shape of the winding needle 100 will gradually approach a cylindrical shape, and will cause the pole piece gap of the electrode assembly 200 to gradually decrease. Therefore, having three outer side surfaces 101 of the winding needle 100 can make the pole piece gap of the electrode assembly 200 at the corners larger.

[0105] refer to Figures 2 to 4In some embodiments, the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 ranges from 0.1 to 10. For example, the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 can be 0.1, 0.2, 0.5, 0.7, 1, 2, 3, 5, 7, 9, 10 or other values.

[0106] When the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 is approximately close to 1, the closer the lengths of the two second sides 1012 are; when the difference between the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 and 1 is large, it is easier to form a smaller angle among the three angles formed between the three outer side surfaces 101, and the spacing between the first pole piece 61 and the adjacent second pole piece 62 of the electrode assembly 200 can be larger at the angle.

[0107] Since the angle between the two outer side surfaces 101 is too small, it is easy to cause a high degree of wear of the electrode assembly 200 during the winding process, thereby easily causing damage to the electrode assembly 200; by making the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 within this range, the angle of any of the three angles formed between the three outer side surfaces 101 will not be too small, thereby reducing the damage of the electrode assembly 200 during the winding process, and the spacing between the first pole piece 61 and the adjacent second pole piece 62 of the electrode assembly 200 can be increased.

[0108] For example, the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 can be 0.1 or 10. In this case, there is at least one smallest angle among the three angles formed between the three outer side surfaces 101, and the spacing between the first pole piece 61 and the adjacent second pole piece 62 of the electrode assembly 200 is the largest at this angle.

[0109] For example, the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 can be 0.2 or 5. In this case, there is at least one smaller angle among the three angles formed between the three outer side surfaces 101, and the spacing between the first pole piece 61 and the adjacent second pole piece 62 of the electrode assembly 200 is larger at this angle.

[0110] For example, the ratio of the lengths of any two of the three second sides 1012 of the outer side surface 101 may be 1.

[0111] This embodiment provides some dimensional relationships between the three outer side surfaces 101, so that the ratio of the lengths of the second sides 1012 of any two outer side surfaces 101 is in the range of 0.1 to 10. This setting can not only reduce the wear of the electrode assembly 200 at the edges of the winding needle 100 during the winding process, but also increase the electrode gap of the electrode assembly 200 at the edges of the winding needle 100.

[0112] refer to Figures 2 to 4 In some embodiments, at least two of the second sides 1012 of the three outer sides 101 are of equal length. In this case, the three second sides 1012 can form an isosceles triangle, and the winding needle 100 can be an isosceles triangular prism structure. When the electrode assembly 200 is wound on the winding needle 100, this arrangement enables the wound electrode assembly 200 to have a more regular shape, thereby facilitating subsequent shaping operations.

[0113] Making the lengths of at least two of the second sides 1012 of the three outer side surfaces 101 equal can also facilitate setting the angles between the three outer side surfaces 101, thereby alleviating damage to the electrode assembly 200 that may be caused by a too small angle.

[0114] In this embodiment, the winding needle 100 is an isosceles triangular prism; this setting can not only further reduce the wear of the electrode assembly 200 at the edges of the winding needle 100 during the winding process, but also increase the pole piece gap of the electrode assembly 200 at the edges of the winding needle 100.

[0115] refer to Figure 2 , Figure 4 In some embodiments, the lengths of the second sides 1012 of the three outer sides 101 are all equal. In this case, the three second sides 1012 can form an equilateral triangle, and the winding needle 100 can be a regular triangular prism structure. When the electrode assembly 200 is wound on the winding needle 100, this arrangement enables the wound electrode assembly 200 to have a more regular shape, thereby facilitating subsequent shaping operations.

[0116] When the lengths of the second sides 1012 of the three outer sides 101 are equal, the angle between any two adjacent outer sides 101 is 60°, thereby better reducing the wear of the electrode assembly 200 at the edge of the winding needle 100 and increasing the pole piece gap of the electrode assembly 200 at the edge of the winding needle 100.

[0117] refer to Figure 5 , Figure 5It is a front view schematic diagram when the winding needle 100 is in the shape of a regular triangular prism, in which C1 is the length of the first pole piece 61 relative to any outer side surface 101, and C2 is the length of the second pole piece 62 relative to any outer side surface 101. In the figure, the second pole piece 62 is located outside the first pole piece 61, and the electrode assembly 200 is wound around the winding needle 100 for one circle.

[0118] refer to Figure 6 , Figure 6 It is the shape of the electrode assembly 200 after winding on the winding needle 100 and being shaped. In the figure, L1 is the length of the first pole piece 61 in the width direction of the electrode assembly 200, L2 is the length of the second pole piece 62 in the width direction of the electrode assembly 200, D is the thickness of the diaphragm 63, D is also the distance between the first pole piece 61 and the second pole piece 62 at the flat part of the electrode assembly 200, and h1 is the distance between the first pole piece 61 and the second pole piece 62 at the corner of the electrode assembly 200.

[0119] Figure 6 In the figure, it is assumed that the first pole piece 61 and the second pole piece 62 are both approximately folded after the electrode assembly 200 is shaped, then L1 = 1.5*C1, L2 = 1.5*C2, at this time:

[0120] h1=(L2-L1) / 2=0.75*(C2-C1)=0.75*(C1+2D / tan30°-C1)=2.59*D.

[0121] refer to Figure 7 , Figure 7 It is a front view schematic diagram when the winding needle 100 is cylindrical. In the figure, R1 is the inner diameter of the first pole piece 61, and R2 is the inner diameter of the second pole piece 62. At this time, the second pole piece 62 is located outside the first pole piece 61. In the figure, the electrode assembly 200 is wound around the winding needle 100 for one circle.

[0122] Figure 8 It is the shape of the electrode assembly 200 after winding on the winding needle 100 and being shaped. In the figure, L3 is the length of the first pole piece 61 in the width direction of the electrode assembly 200, L4 is the length of the second pole piece 62 in the width direction of the electrode assembly 200, D is the thickness of the diaphragm 63, D is also the distance between the first pole piece 61 and the second pole piece 62 at the flat part of the electrode assembly 200, and h2 is the distance between the first pole piece 61 and the second pole piece 62 at the corner of the electrode assembly 200.

[0123] Figure 8 In the figure, it is assumed that the first pole piece 61 and the second pole piece 62 are both approximately folded after the electrode assembly 200 is shaped, then L3 = π*R1, L4 = π*R2, at this time:

[0124] h2=(L2-L1) / 2=π / 2*(R2-R1)=1.57*D.

[0125] According to the above calculations, when the winding needle 100 is a regular triangular prism structure, the distance between the first pole piece 61 and the second pole piece 62 at the corner of the electrode assembly 200 is increased to facilitate the entry of more electrolyte, thereby better improving the battery life.

[0126] refer to Fig. 9 In some embodiments, there are four outer side surfaces 101; two adjacent outer side surfaces 101 intersect to form a third side 1013, the outer side surface 101 and the end surface 102 intersect to form a fourth side 1014, and the fourth side 1014 is formed between the two third sides 1013 and intersects with both third sides 1013; the four fourth sides 1014 form a quadrilateral.

[0127] The third side 1013 refers to the side formed by the intersection of two adjacent outer side surfaces 101, that is, the outer side surface 101 intersects with another adjacent outer side surface 101 at the third side 1013, and can enable the winding needle 100 to form an edge at the third side 1013; in the same outer side surface 101, there are two third sides 1013 and they are arranged opposite to each other along the circumference of the winding needle 100, and the two third sides 1013 of the same outer side surface 101 are respectively formed by the outer side surface 101 and the outer side surfaces 101 on the adjacent two sides intersecting; the two third sides 1013 can be parallel to each other, or they can be non-parallel to each other and intersect on the extension lines of the two.

[0128] For example, two adjacent outer side surfaces 101 are connected at their third edges 1013 . At this time, the third edges 1013 of the two outer side surfaces 101 overlap and form an edge of the winding needle 100 .

[0129] The fourth side 1014 refers to the side formed by the intersection of the outer side surface 101 and the end surface 102, that is, the outer side surface 101 is connected to the end surface 102 at the fourth side 1014; in the same outer side surface 101, there are two fourth sides 1014 and they are arranged opposite to each other along the axial direction of the winding needle 100, and the two fourth sides 1014 are formed by the intersection of the outer side surface 101 and the two end surfaces 102 respectively; the two fourth sides 1014 can be parallel to each other, or they can be non-parallel to each other and intersect on the extension line of the two; the fourth side 1014 is also formed between the two third sides 1013 and intersects with both third sides 1013, and the fourth side 1014 can be perpendicular to the third side 1013, or it can be arranged at other angles with the third side 1013.

[0130] The four fourth sides 1014 can form a quadrilateral. In this case, the winding needle 100 can be a quadrangular prism, a quadrangular pyramid, or a structure with four edges on the circumference.

[0131] For example, the two third sides 1013 of the same outer side surface 101 are parallel to each other, the two fourth sides 1014 of the same outer side surface 101 are parallel to each other, and the fourth side 1014 is perpendicular to the two third sides 1013. In this case, the outer side surface 101 is a rectangle and the winding needle 100 is a quadrangular prism.

[0132] The quadrilateral may be a parallelogram, a trapezoid, a square or the like. That is, when the winding needle 100 includes four outer side surfaces 101 , the quadrilateral formed by the four fourth sides 1014 at the same end of the four outer side surfaces 101 may be a parallelogram or a trapezoid.

[0133] The quadrilateral formed by the four fourth sides 1014 at the same end of the four outer side surfaces 101 can also be a square. In this case, the angle between any two adjacent outer side surfaces 101 can be 90°. This setting can not only reduce the wear of the edges of the winding needle 100 on the electrode assembly 200, but also increase the pole piece gap of the electrode assembly 200 at the edges of the winding needle 100.

[0134] For example, the two third sides 1013 of the same outer side surface 101 are parallel to each other, the two fourth sides 1014 of the same outer side surface 101 are parallel to each other, and the fourth side 1014 is perpendicular to the two third sides 1013, that is, the outer side surface 101 is a rectangle, and the fourth sides 1014 at the same end of the four outer side surfaces 101 form a square. At this time, the winding needle 100 is a regular quadrangular prism.

[0135] In the present embodiment, there are four outer side surfaces 101, and the winding needle 100 can be a quadrangular prism or a quasi-quadrangular prism structure. As the number of outer side surfaces 101 increases, the shape of the winding needle 100 will gradually approach a cylindrical shape, and will cause the pole piece gap of the electrode assembly 200 to gradually decrease. Therefore, having four outer side surfaces 101 of the winding needle 100 can not only make the pole piece gap of the electrode assembly 200 larger at the corners, but also reduce the damage to the pole piece at the edge of the winding needle 100 caused by excessive bending angles.

[0136] In this embodiment, the end face 102 of the winding needle 100 is a quadrilateral such as a parallelogram, a trapezoid, or a square. This setting can not only reduce the wear of the electrode assembly 200 at the edges of the winding needle 100 during the winding process, but also increase the pole piece gap of the electrode assembly 200 at the edges of the winding needle 100.

[0137] refer to Figure 3 , Figure 4 , Figures 10 to 13 In some embodiments, the winding needle 100 includes at least two sub-needle bodies 10 spliced ​​together; the winding needle 100 also includes an inner needle 20, which is arranged between the at least two sub-needle bodies 10 and is detachably connected to the sub-needle bodies 10.

[0138] The sub-needle body 10 refers to the structure that constitutes the winding needle 100. Multiple sub-needle bodies 10 can be spliced ​​together to form the winding needle 100; the shape of the sub-needle body 10 can be set according to the shape of the winding needle 100, for example, the sub-needle body 10 can be a triangular prism, a quadrangular prism or other shapes; the material of the sub-needle body 10 can be set according to the material of the winding needle 100, for example, the material of the sub-needle body 10 can include metal, plastic or other materials.

[0139] There may be two, three or more sub-needle bodies 10; for example, at least two sub-needle bodies 10 may be arranged in sequence along the circumference of the winding needle 100, that is, at least two sub-needle bodies 10 are arranged around the axis of the winding needle 100 and spliced ​​to form the winding needle 100.

[0140] Since the winding needle 100 is formed by splicing at least two sub-needle bodies 10, and each sub-needle body 10 has multiple side surfaces arranged along its circumference, the outer side surface 101 can also be the side surface of one sub-needle body 10, or can be formed by splicing the side surfaces of two or more sub-needle bodies 10.

[0141] Since the winding needle 100 is formed by sub-needle bodies 10 arranged along the circumference of the winding needle 100 , and each sub-needle body 10 has sub-end faces 102 arranged at intervals along its axial direction, the end face 102 of the winding needle 100 is formed by splicing the sub-end faces 102 of two or more sub-needle bodies 10 .

[0142] For example, when there are two sub-needle bodies 10 and both are in the shape of a triangular prism, the two sub-needle bodies 10 are arranged along the circumference of the winding needle 100, that is, the two sub-needle bodies 10 are arranged side by side along the radial direction of the winding needle 100. According to the splicing method of the sub-needle bodies 10, the winding needle 100 can be in the shape of a triangular prism; at this time, an outer side surface 101 of the winding needle 100 is formed by splicing the side surfaces of the two sub-needle bodies 10, and the end surface 102 of the winding needle 100 is formed by splicing the sub-end surfaces 102 of the two sub-needle bodies 10.

[0143] For example, when there are four sub-needle bodies 10 and they are all quadrangular prisms, the four sub-needle bodies 10 are arranged along the circumference of the winding needle 100. According to the splicing method of the sub-needle bodies 10, the winding needle 100 can be in the shape of a quadrangular prism; at this time, the outer side surface 101 of the winding needle 100 is formed by splicing each sub-needle body 10, and the end face 102 of the winding needle 100 is formed by splicing the sub-end faces 102 of the four sub-needle bodies 10.

[0144] The inner needle 20 refers to a structure that is arranged inside the winding needle 100 and can drive the winding needle 100 to rotate. The inner needle 20 can be connected to an external driving structure to rotate under the drive of an external driving force, thereby driving the winding needle 100 to rotate; the inner needle 20 can be a rectangular parallelepiped, or a hexagonal prism, a cylindrical shape or other regular shapes. The inner needle 20 can also be L-shaped, cross-shaped or other irregular shapes; the material of the inner needle 20 can include metal, plastic or other materials.

[0145] The inner needle 20 is arranged between at least two sub-needle bodies 10. During the splicing process of at least two sub-needle bodies 10, the at least two sub-needle bodies 10 can clamp the inner needle 20 and make the inner needle 20 inside the winding needle 100; the inner needle 20 is detachably connected to the sub-needle body 10. For example, the inner needle 20 can be detachably connected to the sub-needle body 10 by screwing, clamping or other methods.

[0146] The inner needle 20 can also be connected to an external driving structure and rotate under the driving force of the external driving structure. The rotation of the inner needle 20 can also drive the connected sub-needle body 10 to rotate, thereby achieving the effect of driving the winding needle 100 to rotate and winding the electrode assembly 200.

[0147] It can be understood that, in addition to being connected to the inner needle 20, the sub-needle body 10 can also be detachably connected to another adjacent sub-needle body 10 by means of screw connection, snap connection, etc.

[0148] In this embodiment, the winding needle 100 includes at least two sub-needle bodies 10, and the sub-needle body 10 is detachably connected to the inner needle 20, so that the external driving structure drives the sub-needle body 10 to rotate synchronously through the inner needle 20, thereby driving the entire winding needle 100 to rotate to wind the electrode assembly 200; the winding needle 100 includes at least two sub-needle bodies 10, which also facilitates the installation, disassembly and replacement of the inner needle 20.

[0149] refer to Figure 3 , Figure 4 , Figures 10 to 13 In some embodiments, a receiving groove 11 is provided on the sub-needle body 10 , and the receiving groove 11 is used to receive at least a portion of the inner needle 20 .

[0150] The accommodating groove 11 refers to the groove structure on the sub-needle body 10 for accommodating the inner needle 20. The accommodating groove 11 is used to accommodate at least part of the inner needle 20, that is, the inner needle 20 can be fully accommodated in the accommodating groove 11, or only partially accommodated in the accommodating groove 11; along the radial direction of the accommodating groove 11, the cross-sectional shape of the accommodating groove 11 can be square, semicircular, trapezoidal or other shapes.

[0151] The inner needle 20 can be clamped in the receiving groove 11 and against the inner wall of the receiving groove 11, or it can be detachably connected to the inner wall of the receiving groove 11 by means of screw connection or the like. The inner needle 20 can also be connected to other positions of the sub-needle body 10 except the receiving groove 11, so that at least part of the inner needle 20 is accommodated in the receiving groove 11.

[0152] It can be understood that the receiving groove 11 should be arranged on the side of the sub-needle body 10 facing the inside of the winding needle 100, and should not be arranged on the surface of the sub-needle body 10 facing the outside of the winding needle 100. This is because the electrode assembly 200 will contact and touch the surface of the sub-needle body 10 facing the outside of the winding needle 100 during the process of winding on the winding needle 100. This arrangement can reduce the wear and other damages that may be caused to the electrode assembly 200 by the receiving groove 11 and the inner needle 20.

[0153] Because the winding needle 100 is formed by splicing multiple sub-needle bodies 10, and the inner needle 20 is connected to each sub-needle body 10, at least part of the inner needle 20 is accommodated in the accommodating groove 11, which can reduce the distance between two adjacent sub-needle bodies 10; if the distance between two adjacent sub-needle bodies 10 is too large, part of the electrode assembly 200 may enter the distance during the winding process, which may easily cause the electrode assembly 200 to bend and be damaged, and easily have a negative impact on the composite of the electrode plate and the diaphragm 63.

[0154] In this embodiment, a receiving groove 11 is provided on the sub-needle body 10 to accommodate the inner needle 20 through the receiving groove 11; because the inner needle 20 is provided between the two sub-needle bodies 10, it is easy to cause a larger distance between the two sub-needle bodies 10, and this distance is too large to easily cause the electrode assembly 200 to deform at the distance during the winding process. Providing the receiving groove 11 on the sub-needle body 10 and allowing at least part of the inner needle 20 to be accommodated in the receiving groove 11 can reduce the distance between the two sub-needle bodies 10, thereby reducing the negative impact of the distance on the winding of the electrode assembly 200.

[0155] refer to Figure 3 , Figure 4 , Figures 10 to 13 In some embodiments, a fixing hole 12 is opened on the sub-needle body 10, and one end of the fixing hole 12 is connected to the accommodating groove 11; the winding needle 100 also includes a fixing member 30 detachably connected to the sub-needle body 10, one end of the fixing member 30 is accommodated in the fixing hole 12, and the other end abuts against the inner needle 20.

[0156] The fixing hole 12 refers to a hole structure opened on the sub-needle body 10. The fixing hole 12 can be a circular hole, a square hole or a hole of other shapes. The fixing hole 12 can be a through hole, or a stepped hole, a threaded hole or a hole of other shapes. There can be one fixing hole 12, or there can be two, three or more.

[0157] The fixing part 30 refers to the structure in the winding needle 100 used to fix the inner needle 20 to the sub-needle body 10. The fixing part 30 can be a rivet, a bolt, a pin or other structure; there can be one fixing part 30, or there can be two or more fixing parts 30; the material of the fixing part 30 can include metal, plastic or other materials.

[0158] One end of the fixing hole 12 is connected to the accommodating groove 11, so that one end of the fixing member 30 can be accommodated in the fixing hole 12, and the other end can abut against the inner needle 20. The fixing member 30 abuts against one end of the inner needle 20 to fix the inner needle 20 in the accommodating groove 11, so that the rotation of the inner needle 20 can drive the sub-needle body 10 to rotate.

[0159] The fixing member 30 can fix the sub-needle body 10 in a variety of different ways. In some embodiments, the fixing member 30 can be a bolt, in which case the fixing hole 12 can be a threaded hole, the fixing member 30 can cooperate with the thread of the threaded hole, and one end of the fixing member 30 can press the inner needle 20 against the inner wall of the receiving groove 11; in other embodiments, the fixing member 30 can also be a bayonet, in which case a through hole or a slow blind hole can be opened on the inner needle 20, so that one end of the fixing member 30 can enter the through hole or the blind hole and abut against the inner needle 20; it can be understood that the fixing member 30 can also fix the inner needle 20 to the sub-needle body 10 in other ways, not limited to the above two ways.

[0160] Depending on the type of the fixing piece 30, the other end of the fixing hole 12 can pass through the sub-needle body 10 and be connected to the space outside the sub-needle body 10, so that the fixing piece 30 can enter the fixing hole 12, and one end of the fixing piece 30 can enter the receiving groove 11 and abut against the inner needle 20; the other end of the fixing hole 12 may not pass through the sub-needle body 10, that is, in this case the fixing hole 12 is a blind hole and one end is connected to the receiving groove 11. In this case, the fixing piece 30 can first enter the fixing hole 12 through the receiving groove 11, and after at least part of the inner needle 20 is accommodated in the receiving groove 11, the fixing piece 30 can abut against the inner needle 20.

[0161] The present embodiment provides some specific structures for connecting the inner needle 20 with the sub-needle body 10. A fixing hole 12 connected to the receiving groove 11 is provided on the sub-needle body 10, so that one end of the fixing member 30 can abut against the inner needle 20 to fix the inner needle 20 in the receiving groove 11, and the other end of the fixing member 30 is accommodated in the fixing hole 12, so as to reduce the interference of the fixing member 30 extending outside the winding needle 100 with the winding of the electrode assembly 200.

[0162] refer to Figure 3 , Figure 4 , Figures 10 to 13 In some embodiments, at least two sub-needle bodies 10 are spaced apart and a clamping space 40 is formed between the two sub-needle bodies 10, and the clamping space 40 is used to accommodate a portion of the electrode assembly 200; at least one of the two sub-needle bodies 10 on both sides of the clamping space 40 can move relative to the other to get closer to or away from the other.

[0163] At least two sub-needle bodies 10 are arranged at intervals, so that a clamping space 40 is formed between the two sub-needle bodies 10, that is, according to the number of sub-needle bodies 10, there can be only two sub-needle bodies 10 arranged at intervals, or there can be multiple sub-needle bodies 10 arranged at intervals, one sub-needle body 10 can also be arranged at intervals only with another adjacent sub-needle body 10, or one sub-needle body 10 can also be arranged at intervals with multiple adjacent sub-needle bodies 10; the corresponding clamping space 40 can be only one, or there can be two or more.

[0164] For example, the winding needle 100 is formed by splicing two sub-needle bodies 10 , and the two sub-needle bodies 10 are spaced apart to form a clamping space 40 .

[0165] For example, the winding needle 100 is formed by splicing three sub-needle bodies 10 , two of the three sub-needle bodies 10 are spaced apart to form a clamping space 40 , and the other sub-needle body 10 is closely connected to the two sub-needle bodies 10 .

[0166] For example, the winding needle 100 is formed by splicing four sub-needle bodies 10, and the four sub-needle bodies 10 are arranged in pairs to form two mutually connected clamping spaces 40.

[0167] The clamping space 40 is used to accommodate at least a portion of the electrode assembly 200 . When the electrode assembly 200 is initially wound on the winding needle 100 , a portion of the electrode assembly 200 (eg, the diaphragm 63 ) may enter the clamping space 40 .

[0168] At least one of the two sub-needle bodies 10 on both sides of the clamping space 40 can move relative to the other, that is, the two sub-needle bodies 10 on both sides of the clamping space 40 can both be movable structures, or only one can be movable and the other is a fixed structure; accordingly, the two sub-needle bodies 10 on both sides of the clamping space 40 can relatively approach each other or move away from each other, and the relative approach of the two sub-needle bodies 10 on both sides of the clamping space 40 can enable the two sub-needle bodies 10 to clamp the part of the electrode assembly 200 in the clamping space 40 to play a fixing role, so that the winding needle 100 can rotate to wind the electrode assembly 200 onto the winding needle 100, and it is not easy for the electrode assembly 200 to slide relative to the winding needle 100, thereby causing winding failure; the relative movement of the two sub-needle bodies 10 on both sides of the clamping space 40 can loosen the electrode assembly 200, so as to facilitate the removal of the electrode assembly 200 from the winding needle 100 after winding.

[0169] In this embodiment, a clamping space 40 is provided between the two sub-needle bodies 10 so that part of the electrode assembly 200 can be accommodated in the clamping space 40; at least one of the two sub-needle bodies 10 is able to move closer to or away from the other, so that the two sub-needle bodies 10 can clamp part of the electrode assembly 200 in the clamping space 40, thereby fixing the end of the electrode assembly 200 and facilitating winding of the electrode assembly 200 on the winding needle 100.

[0170] refer to Fig.14 In some embodiments, an air extraction channel 52 is provided inside the sub-needle body 10 , and an adsorption hole 51 having one end connected to the air extraction channel 52 is provided on the outer side surface 101 .

[0171] The exhaust channel 52 refers to a channel structure inside the sub-needle body 10 for gas circulation. The exhaust channel 52 can be formed by embedding a pipe fitting inside the sub-needle body 10, or by opening a groove structure inside the sub-needle body 10. Along the radial direction of the exhaust channel 52, the cross-sectional shape of the exhaust channel 52 can be square, circular, trapezoidal or other shapes. The exhaust channel 52 can also extend in a straight line or be curved.

[0172] The adsorption hole 51 refers to a structure on the sub-needle body 10 for circulating air and adsorbing the electrode assembly 200. The adsorption hole 51 can be a square hole, a circular hole, or a hole structure of other shapes. The adsorption hole 51 can be a stepped hole, a threaded hole, or a hole structure of other shapes. The adsorption hole 51 can extend along a straight line or a curve. There can be one adsorption hole 51, or there can be two or more.

[0173] The adsorption hole 51 is opened on the outer side surface 101, that is, one end of the adsorption hole 51 can be connected with the space outside the sub-needle body 10, and one end of the adsorption hole 51 is connected with the exhaust channel 52, so that the air flow can enter the exhaust channel 52 through the adsorption hole 51; one end of the exhaust channel 52 can be connected with the exhaust structure (such as an air pump, etc.), and when the exhaust structure is activated, the air outside the sub-needle body 10 can enter the exhaust channel 52 through the adsorption hole 51 and enter the exhaust structure.

[0174] When the air flows through the adsorption holes 51 and enters the exhaust channel 52 , the electrode assembly 200 can also be adsorbed and fixed on the outer side surface 101 , so that the structure of the adsorption holes 51 and the exhaust channel 52 plays a role in fixing the electrode assembly 200 .

[0175] Accordingly, a plurality of adsorption holes 51 may be provided and arranged regularly on the outer surface 101. For example, the adsorption holes 51 may be arranged in a rectangular array on the outer surface 101. The aperture of the adsorption holes 51 and the distance between adjacent adsorption holes 51 may be set according to the required adsorption force.

[0176] When the electrode assembly 200 needs to be wound on the winding needle 100, the exhaust structure can be started. At this time, the air flows through the adsorption hole 51 into the exhaust channel 52. When the electrode assembly 200 is close to the winding needle 100, the electrode assembly 200 can also be adsorbed and contact the outer side surface 101, so that the electrode assembly 200 can be pressed and fixed to the outer side surface 101 by air pressure, and play a fixing role; in the process of winding the electrode assembly 200 on the winding needle 100, this setting can fix the part of the electrode assembly 200 that contacts the winding needle 100, so that the winding needle 100 can rotate to wind the electrode assembly 200 onto the winding needle 100, and it is not easy for the electrode assembly 200 to slide relative to the winding needle 100, thereby causing winding failure.

[0177] In this embodiment, an exhaust channel 52 is provided in the sub-needle body 10, and an adsorption hole 51 connected to the exhaust channel 52 is provided on the sub-needle body 10, so that the winding needle 100 can adsorb and fix part of the electrode assembly 200 on the winding needle 100 by exhausting air from the exhaust channel 52 to the outside of the winding needle 100, thereby achieving the fixation of the end of the electrode assembly 200 and facilitating the winding of the electrode assembly 200 on the winding needle 100.

[0178] refer to Figures 9 to 14 In some embodiments, a material discharge groove 13 extending radially along the winding needle 100 is further provided on the outer side surface 101 ; in the radial direction of the winding needle 100 , at least one end of the material discharge groove 13 is connected to the space outside the winding needle 100 .

[0179] The material discharge trough 13 refers to a trough structure on the winding needle 100 for accommodating a material picking device. The material discharge trough 13 is opened on the outer side surface 101, that is, the opening of the material discharge trough 13 faces the outside of the winding needle 100. After the electrode assembly 200 is wound on the winding needle 100, the electrode assembly 200 can close the opening of the material discharge trough 13; at least one end of the material discharge trough 13 along the radial direction of the winding needle 100 is connected to the space outside the winding needle 100; along the radial direction of the material discharge trough 13, the cross-sectional shape of the material discharge trough 13 can be square, semicircular, trapezoidal or other shapes.

[0180] In such a winding needle 100, the material picking device can enter the material discharge groove 13 along the radial direction of the winding needle 100, and can also move in the direction away from the axis of the winding needle 100, and can move from the opening of the material discharge groove 13 to the outside of the winding needle 100 to contact the electrode assembly 200; after contacting the electrode assembly 200, the material picking device can continue to move in the direction away from the axis of the winding needle 100 and make the electrode assembly 200 separate from the winding needle 100, so as to facilitate the removal of the electrode assembly 200 from the winding needle 100.

[0181] When the winding needle 100 is formed by splicing a plurality of sub-needle bodies 10 , the material discharge groove 13 can be provided on one or more sub-needle bodies 10 ; for example, the winding needle 100 is formed by splicing two sub-needle bodies 10 , and the two sub-needle bodies 10 are both provided with a material discharge groove 13 .

[0182] In the case where the winding needle 100 comprises only one main body structure, one or more feeding slots 13 may be provided on the main body structure.

[0183] In this embodiment, a material discharge slot 13 is provided on the sub-needle body 10 , so that the material discharge equipment can extend into the wound electrode assembly 200 and remove the electrode assembly 200 from the winding needle 100 .

[0184] In some embodiments, an air extraction channel 52 is provided inside the winding needle 100 , and an adsorption hole 51 having one end connected to the air extraction channel 52 is provided on the outer side surface 101 .

[0185] When the winding needle 100 only includes a main structure and is not formed by splicing multiple sub-needle bodies 10, an exhaust channel 52 is opened inside the winding needle 100, and one end of the exhaust channel 52 can be connected to the exhaust structure; an adsorption hole 51 is also opened on the outer side surface 101 of the winding needle 100, one end of the adsorption hole 51 is connected to the space outside the winding needle 100, and the other end of the adsorption hole 51 is connected to the exhaust channel 52.

[0186] In such a winding needle 100, when the electrode assembly 200 needs to be wound on the winding needle 100, the vacuum structure can be activated. At this time, the air flows through the adsorption hole 51 into the vacuum channel 52. When the electrode assembly 200 is close to the winding needle 100, the electrode assembly 200 can also be adsorbed and contacted with the outer side surface 101, so that the electrode assembly 200 can be pressed and fixed to the outer side surface 101 by air pressure, and play a fixing role.

[0187] In this embodiment, an exhaust channel 52 is provided in the winding needle 100, and an adsorption hole 51 connected to the exhaust channel 52 is provided on the outer side surface 101, so that the winding needle 100 can adsorb and fix part of the electrode assembly 200 on the winding needle 100 by exhausting air from the exhaust channel 52 to the outside of the winding needle 100, thereby achieving the fixation of the end of the electrode assembly 200 and facilitating the winding of the electrode assembly 200 on the winding needle 100.

[0188] In some embodiments, the winding needle 100 includes three rectangular outer side surfaces 101 and end surfaces 102 parallel to each other at both ends, the two first sides 1011 of the outer side surfaces 101 are parallel to each other, the two second sides 1012 of the outer side surfaces 101 are parallel to each other, and the second sides 1012 are perpendicular to the two first sides 1011, that is, the winding needle 100 is a regular triangular prism structure.

[0189] The winding needle 100 is formed by two sub-needle bodies 10, and both sub-needle bodies 10 are triangular prism-shaped structures.

[0190] There are accommodating grooves 11 on the opposite sides of the two sub-needle bodies 10, and the two sub-needle bodies 10 can be close to and fit together. At this time, the two accommodating grooves 11 are also spliced ​​together to form an accommodating space, and the inner needle 20 is accommodated in the accommodating space; a plurality of fixing holes 12 are provided on the sub-needle, one end of the fixing hole 12 is connected to the space outside the winding needle 100, and the other end of the fixing hole 12 is connected to the accommodating groove 11, one end of the fixing piece 30 holds the inner needle 20 against the inner wall of the accommodating groove 11, and the other end of the fixing piece 30 is accommodated in the fixing hole 12.

[0191] An air extraction channel 52 is provided in the sub-needle body 10, and the air extraction channel 52 can be connected to the air extraction structure; an adsorption hole 51 is provided on the side wall of the sub-needle body 10 facing the winding needle 100, one end of the adsorption hole 51 is connected to the space outside the winding needle 100, and the other end of the adsorption hole 51 is connected to the air extraction channel 52; the adsorption holes 51 are arranged in a rectangular array on the side wall of the sub-needle body 10 facing the winding needle 100.

[0192] In the second aspect, some embodiments of the present application also include a winding device, including the winding needle 100 provided by some embodiments of the first aspect. The electrode assembly 200 formed by the winding arrangement can have a larger electrode gap at the corner after shaping, so that more electrolyte can enter the electrode gap, thereby extending the life of the battery.

[0193] On the third aspect, some embodiments of the present application also include a battery processing system, including the winding equipment provided by some embodiments of the second aspect, the battery processing system can wind the electrode assembly 200, and the wound electrode assembly 200 can have a larger electrode gap at the corner after shaping, so that more electrolyte can enter the electrode gap, thereby extending the life of the battery.

[0194] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A winding needle for winding an electrode assembly, characterized in that: The winding needle comprises two end surfaces, and along the axial direction of the winding needle, the two end surfaces are arranged at intervals; The winding needle further includes at least three outer side surfaces which are connected in sequence end to end along the circumference of the winding needle. The outer side surfaces are used to abut against the electrode assembly. Both ends of the outer side surfaces along the axial direction of the winding needle are respectively connected to the two end surfaces.

2. The winding needle according to claim 1, characterized in that: There are three outer sides; Two adjacent outer side surfaces intersect to form a first side, the outer side surface intersects with the end surface to form a second side, and the second side is formed between the two first sides and intersects with both of the first sides; The three second sides form a triangle.

3. The winding needle according to claim 2, characterized in that: The ratio of the lengths of any two of the three second sides of the three outer side surfaces is in the range of 0.1-10.

4. The winding needle according to claim 2 or 3, characterized in that: At least two of the three second sides of the three outer side surfaces have the same length.

5. The winding needle according to any one of claims 2 to 4, characterized in that: The lengths of the three second sides of the three outer side surfaces are all equal.

6. The winding needle according to claim 1, characterized in that: There are four outer sides; Two adjacent outer side surfaces intersect to form a third side, the outer side surface and the end surface intersect to form a fourth side, and the fourth side is formed between the two third sides and intersects with both the third sides; The four fourth sides form a quadrilateral.

7. The winding needle according to any one of claims 1 to 6, characterized in that: The winding needle comprises at least two sub-needle bodies spliced ​​together; The winding needle also includes an inner needle, which is arranged between at least two of the sub-needle bodies and is detachably connected to the sub-needle bodies.

8. The winding needle according to claim 7, characterized in that: The sub-needle body is provided with a receiving groove, and the receiving groove is used to receive at least a part of the inner needle.

9. The winding needle according to claim 8, characterized in that: A fixing hole is provided on the sub-needle body, and one end of the fixing hole is connected to the accommodating groove; The winding needle also includes a fixing member detachably connected to the sub-needle body, one end of the fixing member is accommodated in the fixing hole, and the other end abuts against the inner needle.

10. The winding needle according to any one of claims 7 to 9, characterized in that: At least two of the sub-needle bodies are arranged at intervals, and a clamping space is formed between the two sub-needle bodies, and the clamping space is used to accommodate a part of the electrode assembly; At least one of the two sub-needle bodies on both sides of the clamping space can move relative to the other to approach or move away from the other.

11. The winding needle according to any one of claims 7 to 9, characterized in that: An air extraction channel is provided inside the sub-needle body, and an adsorption hole with one end connected to the air extraction channel is provided on the outer surface.

12. The winding needle according to any one of claims 1 to 6, characterized in that: The outer surface is also provided with a feeding groove extending in the radial direction of the winding needle; In the radial direction of the winding needle, at least one end of the material discharge groove is communicated with the space outside the winding needle.

13. The winding needle according to any one of claims 1 to 6, characterized in that: An air extraction channel is provided inside the winding needle, and an adsorption hole having one end connected to the air extraction channel is provided on the outer surface.

14. A winding device, characterized in that: The invention comprises a winding needle as claimed in any one of claims 1 to 13.

15. A battery processing system, characterized in that: Comprising the winding apparatus of claim 14.

Images