Winding needle, winding device, battery manufacturing equipment and winding method

Abstract

The embodiment of the invention provides a winding needle, a winding device, battery manufacturing equipment and a winding method. The winding device comprises a winding needle, a pair of first clamping needles and at least one second clamping needle, the pair of first clamping needles are configured to move in the direction away from each other after the winding needle is pulled away from the electrode assembly so as to open the electrode assembly, and the second clamping needle is configured to move in the direction away from the electrode assembly in the process that the pair of first clamping needles open the electrode assembly. And the upper half part of the electrode assembly is supported. The winding needle comprises a winding needle body, a pair of first grooves are formed in the peripheral face of the winding needle body, the first grooves are used for containing first clamping needles, the pair of first grooves are formed in the peripheral direction of the winding needle body at intervals, at least one second groove is further formed in the peripheral face of the winding needle body, and the second grooves are used for containing second clamping needles. And the second grooves and the first grooves are arranged at intervals along the circumferential direction of the winding needle body. According to the technical scheme, the reliability of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of battery production, and in particular to a winding needle, a winding device, a battery manufacturing equipment and a winding method. 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 development of battery technology, how to improve battery reliability is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a winding needle, a winding device, a battery manufacturing equipment and a winding method, which can improve the reliability of the battery.

[0005] This application is achieved through the following technical solutions:

[0006] In the first aspect, the present application provides a winding needle, including a winding needle body, a pair of first grooves are arranged on the outer circumferential surface of the winding needle body, the first groove is used to accommodate the first clamping needle, and the pair of first grooves are arranged at intervals along the circumference of the winding needle body; wherein, at least one second groove is also arranged on the outer circumferential surface of the winding needle body, the second groove is used to accommodate the second clamping needle, and the second groove and the first groove are arranged at intervals along the circumference of the winding needle body.

[0007] The technical solution of the embodiment of the present application is to provide a pair of circumferentially spaced first grooves and a second groove different from the first groove on the outer circumferential surface of the winding needle body. When in use, the pair of first grooves are arranged on both sides in the vertical direction, and the second groove is arranged above the line connecting the pair of first grooves. The electrode assembly is formed by winding the outer circumferential surface of the winding needle body, and the first clamping needle is accommodated by the first groove, and the second clamping needle is accommodated by the second groove, thereby determining the positions of the first clamping needle and the second clamping needle. In the subsequent stretching process of the electrode assembly, the second clamping needle whose position is determined by the second groove abuts against the upper half of the electrode assembly, thereby reducing the descending speed of the upper half, reducing the risk of the upper half collapsing due to the rapid descent of the upper half due to gravity, thereby causing wrinkling, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0008] In some embodiments, a pair of first grooves are arranged 180° apart along the circumference of the winding needle body.

[0009] The technical solution of the embodiment of the present application is to set a pair of first grooves at an interval of 180° on the outer circumferential surface of the winding needle body, wherein the electrode assembly is formed by winding the outer circumferential surface of the winding needle body, and the pair of first grooves are set on both sides in the vertical direction, that is, the pair of first grooves are located on the diameter of the electrode assembly in the horizontal direction, and the first groove is used to accommodate the first clamping needle. In the subsequent stretching process of the electrode assembly, the first clamping needles are separated from each other in the horizontal direction, which can achieve the best stretching effect of the electrode assembly and facilitate the setting of the second groove, thereby improving convenience.

[0010] In some embodiments, in the circumferential direction of the winding needle body, the angle between the second groove and one of the first grooves is α, satisfying: 45°≤α≤90°.

[0011] In the technical solution of the embodiment of the present application, the angle between the second groove and one of the first grooves is α, and when in use, a pair of first grooves are arranged horizontally, and the second groove is arranged above the first groove, and the first groove is used to accommodate the first clamping needle, and the second groove is used to accommodate the second clamping needle. The size of α corresponds to the position of the second clamping needle corresponding to the wound electrode assembly. When 45°≤α≤90°, the first clamping needle and the second clamping needle are farther apart, that is, the second clamping needle has a higher height in the vertical direction, and the part of the upper half abutted by the second clamping needle is closer to the upper end of the electrode assembly, and the angle deviating from the upper end of the electrode assembly is smaller. The second clamping needle abuts against the upper half of the electrode assembly, which reduces the descending speed of the upper half of the electrode assembly, reduces the risk of the upper half collapsing due to the action of gravity and causing wrinkling, and also reduces the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0012] In some embodiments, 60°≤α≤90°.

[0013] According to the technical solution of the embodiment of the present application, when 60°≤α≤90°, that is, the first clamping needle and the second clamping needle are farther apart, the second clamping needle is closer to the upper end of the electrode assembly, and the angle of deviation from the upper end of the electrode assembly is smaller, and the second clamping needle abuts against the upper half of the electrode assembly, thereby reducing the descending speed of the upper half of the electrode assembly, reducing the risk of the upper half collapsing due to rapid descent of the upper half due to gravity, thereby causing wrinkling, and also reducing the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0014] In some embodiments, 85°≤α≤90°.

[0015] According to the technical solution of the embodiment of the present application, when 85°≤α≤90°, that is, the second clamping needle abuts against the uppermost end of the electrode assembly, and deviates from the uppermost end of the electrode assembly due to positioning error or process reasons, the second clamping needle abuts against the upper half of the electrode assembly, which reduces the descending speed of the upper half of the electrode assembly, reduces the risk of the upper half collapsing due to rapid descent of the upper half due to gravity, and causes wrinkling, and also reduces the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium plating of the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0016] In some embodiments, the outer circumferential surface of the winding needle body is divided into a first area and a second area by a pair of first grooves, and there are multiple second grooves, and the multiple second grooves are all arranged in the first area.

[0017] The technical solution of the embodiment of the present application is that under the action of gravity, only the upper half of the electrode assembly will collapse due to the rapid descent, thereby causing the pole piece or pole ear of the upper half to wrinkle, that is, only the upper half of the electrode assembly needs to be abutted for support. The outer peripheral surface of the winding needle body is divided into a first area and a second area by a pair of first grooves, and a plurality of second grooves are all arranged in the first area. At the same time, when in use, the pair of first grooves are arranged in the horizontal direction, and the second grooves in the first area are arranged above the pair of first grooves. The second groove is used to accommodate the second clamping needle. The second clamping needle abuts the upper half of the electrode assembly, thereby reducing the descending speed of the upper half of the electrode assembly, reducing the risk of the upper half collapsing due to the rapid descent of the upper half due to gravity, thereby causing wrinkles, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium deposition in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery. By setting the second groove in the first area and setting the first area above the first groove when in use, the probability of setting the second clamping needle below the first groove when setting the second clamping needle is reduced, while also saving costs and improving installation convenience.

[0018] In some embodiments, a pair of first grooves are symmetrically arranged relative to the first plane, the central axis of the winding needle body is located on the first plane, and there are multiple second grooves, which are symmetrically arranged relative to the first plane.

[0019] The technical solution of the embodiment of the present application is to arrange multiple second grooves symmetrically relative to the first plane, and the central axis of the winding needle body is located on the first plane, that is, when in use, a pair of first grooves are arranged in the horizontal direction, and the electrode assembly is formed by winding the outer peripheral surface of the winding needle body, and the second grooves are symmetrically arranged relative to the diameter of the electrode assembly in the vertical direction, and the second clamping needles are accommodated in the second grooves, so that the multiple second clamping needles respectively abut the parts of the electrode assembly on both sides of the diameter in the vertical direction, so that the abutting effect of the second clamping needles located on both sides of the diameter of the electrode assembly in the vertical direction is symmetrical, thereby reducing the descending speed of the upper half of the electrode assembly, reducing the risk of the upper half collapsing due to the rapid descent of the upper half due to gravity, thereby causing wrinkling, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0020] In some embodiments, both the first groove and the second groove penetrate the winding needle body along the axial direction of the winding needle body.

[0021] According to the technical solution of the embodiment of the present application, the first groove and the second groove extend along the axial direction of the winding needle body and penetrate the winding needle body, the first groove is used to accommodate the first clamping needle, and the second groove is used to accommodate the second clamping needle, which improves the convenience of the first clamping needle and the second clamping needle during the installation process. By determining the positions of the first groove and the second groove, the positions of the first clamping needle and the second clamping needle are determined, which improves the accuracy of the installation positions of the first clamping needle and the second clamping needle, and also facilitates the removal of the winding needle, reducing the risk of interference between the winding needle and the first clamping needle and the second clamping needle during the removal process.

[0022] In some embodiments, the needle winding body includes a first needle winding portion and a second needle winding portion, a gap is defined between the first needle winding portion and the second needle winding portion, the second groove and one of the first grooves are arranged on the outer peripheral surface of the first needle winding portion, and the other first groove is arranged on the outer peripheral surface of the second needle winding portion.

[0023] The technical solution of the embodiment of the present application is that a winding needle body is composed of a first winding needle part and a second winding needle part, and the first winding needle part and the second winding needle part define a gap, wherein one first groove is arranged on the first winding needle part, and the other first groove is arranged on the second winding needle part. Therefore, when using the winding needle, the size of the gap can be changed by moving the first winding needle part and the second winding needle part, thereby changing the relative position of the first winding needle part and the second winding needle part, thereby realizing fine adjustment of a pair of first grooves during setting, and accommodating the first clamping needle by the first groove, thereby improving the accuracy of the installation position of the first clamping needle, thereby improving the stretching effect of the electrode assembly, improving the reliability of the electrode assembly, and improving the reliability of the battery cell and the battery.

[0024] In the second aspect, the present application also provides a winding device for winding an electrode assembly, comprising a winding needle as in any embodiment of the first aspect, a pair of first clamping needles and at least one second clamping needle, wherein the pair of first clamping needles are configured to move away from each other after the winding needle is pulled out of the electrode assembly to stretch the electrode assembly, and the second clamping needles are configured to support the upper half of the electrode assembly during the process of the pair of first clamping needles stretching the electrode assembly.

[0025] The technical solution of the embodiment of the present application is to set the first clamping needle in the first groove and the second clamping needle in the second groove. After the electrode assembly is wound into shape by the winding needle, the two first clamping needles move away from each other in the horizontal direction and abut against the two inner walls of the electrode assembly opposite to each other in the horizontal direction to stretch the electrode assembly in the horizontal direction. At this time, the two inner walls of the electrode assembly opposite to each other in the vertical direction are close to each other, and the second clamping needle abuts against the upper half of the electrode assembly to reduce the descending speed of the upper half, thereby reducing the risk of the upper half collapsing due to the upper half descending too fast due to gravity, thereby causing wrinkling, and also reduces the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0026] In some embodiments, the second clamping needle has a first wall surface away from the central axis of the winding needle body, and the first wall surface is configured as an arc surface.

[0027] The technical solution of the embodiment of the present application is that the second clamping needle abuts the upper half of the electrode assembly, and the second clamping needle has a first wall surface away from the central axis of the winding needle body, and the first wall surface abutting the upper half of the electrode assembly is an arc surface. Since the electrode assembly after winding is annular, the inner wall of the electrode assembly is an arc surface. Therefore, the first wall surface is constructed as an arc surface, which can make the second clamping needle abut the upper half of the electrode assembly more smooth, reduce the risk of damaging the electrode assembly, and thus improve the reliability of the battery.

[0028] In some embodiments, the winding device further comprises a heating element connected to the second clamping needle to heat the second clamping needle.

[0029] The technical solution of the embodiment of the present application is to set a heating element connected to the second clamping needle for heating the second clamping needle, wherein the second clamping needle is used to abut the upper half of the electrode assembly, the upper half includes a positive electrode sheet, a negative electrode sheet and a diaphragm for bonding the positive and negative electrode sheets, and the heating of the second clamping needle causes the adhesive of the diaphragm in the upper half to melt, thereby making the bonding with the diaphragm and the positive and negative electrode sheets stronger, reducing the risk of wrinkling the electrode sheets, and improving the reliability of the electrode assembly, thereby improving the reliability of the battery.

[0030] In some embodiments, the heating element is a resistive element.

[0031] The technical solution of the embodiment of the present application sets the heating element as a resistance element, which is easy to obtain and easy to achieve the heating effect, thereby improving the convenience of heating.

[0032] In some embodiments, the winding device also includes a first driving member and a second driving member, the first driving member is connected to a pair of first clamping needles to drive the pair of first clamping needles away from each other along a first direction, and the second driving member is connected to the second clamping needle to drive the second clamping needle to move along a second direction, wherein the first direction and the second direction intersect.

[0033] The technical solution of the embodiment of the present application is to drive a pair of first clamping needles away from each other in the first direction by setting a first driving member connected to the first clamping needle, and to drive a second clamping needle to move downward in the second direction by setting a second driving member, so that the two first clamping needles move away from each other in the first direction, and abut against two inner walls of the electrode assembly opposite to each other in the first direction, so as to stretch the electrode assembly in the first direction, so that the second clamping needle moves downward in the second direction, and abuts against the upper part of the electrode assembly during the movement, thereby reducing the descending speed of the upper part, reducing the risk of the upper part collapsing due to the upper part falling too fast due to gravity, thereby causing wrinkles, and also reducing the probability of the pole ear folding when the pole ear is located in the upper part, thereby reducing the risk of lithium deposition in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery. In addition, through mechanized drive, it is easy to control the speed of the first clamping needle and the second clamping needle, and the convenience of operation is also improved.

[0034] In a third aspect, an embodiment of the present application further provides a battery manufacturing device, comprising a winding device as in any one of the embodiments of the second aspect.

[0035] The technical solution of the embodiment of the present application is to complete the winding of the electrode assembly by a winding device, and then manufacture the battery or battery cell by a battery manufacturing device. Among them, the winding device includes a winding needle, a first clamping needle and a second clamping needle, the first clamping needle is set in the first groove of the winding needle, and the second clamping needle is set in the second groove of the winding needle. After the electrode assembly is wound and formed by the winding needle, it is taken out, and the two first clamping needles move away from each other in the horizontal direction, and abut against the two inner walls of the electrode assembly opposite to each other in the horizontal direction, so as to stretch the electrode assembly in the horizontal direction. At this time, the two inner walls of the electrode assembly opposite to each other in the vertical direction are close to each other, wherein the second clamping needle abuts against the upper half of the electrode assembly, reduces the descending speed of the upper half, reduces the risk of the upper half collapsing due to the upper half falling too fast due to gravity, and thus causes wrinkling, and also reduces the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium deposition in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0036] In a fourth aspect, an embodiment of the present application also provides a winding method, comprising: providing a winding needle as in any one of the embodiments of the first aspect; winding the pole piece and the diaphragm with the winding needle to form an electrode assembly; inserting a pair of first clamping needles into a pair of first grooves, and inserting a second clamping needle into the second groove; pulling the winding needle out of the electrode assembly; moving the pair of first clamping needles away from each other to stretch the electrode assembly; in the process of stretching the electrode assembly, supporting the upper half of the electrode assembly by the second clamping needle.

[0037] The technical solution of the embodiment of the present application is to wind the positive and negative electrode sheets and the diaphragm into an electrode assembly by the provided winding needle, then insert the first clamping needle into the first groove of the winding needle, and insert the second clamping needle into the second groove of the winding needle to form a winding device, and then pull the winding needle out of the electrode assembly, so that the first clamping needle and the second clamping needle can move. At this time, a pair of first clamping needles are moved away from each other, abutting against the two inner walls opposite to the electrode assembly while propping up the electrode assembly to achieve stretching of the electrode assembly. At the same time, the second clamping needle supports the upper half of the electrode assembly, reduces the descending speed of the upper half, reduces the risk of the upper half collapsing due to the rapid descent of the upper half due to gravity, thereby causing wrinkling, and also reduces the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0038] In some embodiments, the upper half of the electrode assembly is supported by a second clamping needle so that the movement speed of the area where the upper half contacts the second clamping needle is less than or equal to the movement speed of the area where the lower half of the electrode assembly faces the second clamping needle.

[0039] The technical solution of the embodiment of the present application supports the upper part of the electrode assembly by the second clamping needle, thereby reducing the descending speed of the upper part, so that the moving speed of the contact area between the upper part and the second clamping needle is less than or equal to the moving speed of the area where the lower part of the electrode assembly is directly opposite to the second clamping needle. By comparing the speeds, it is confirmed that the second clamping needle reduces the risk of the upper part collapsing and wrinkling due to the upper part descending too quickly due to gravity, and also reduces the probability of the pole ear folding when it is located in the upper part, thereby reducing the risk of lithium plating of the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0040] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0043] Figure 2 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0044] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0045] Figure 4 A schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application;

[0046] Figure 5 A schematic diagram of the structure of a winding needle provided in some embodiments of the present application;

[0047] Figure 6 for Figure 5 A schematic diagram of the structure of the middle winding needle from another perspective;

[0048] Figure 7 A schematic diagram of the structure of a winding needle provided in some other embodiments of the present application;

[0049] Figure 8 for Figure 7 A schematic diagram of the structure of the middle winding needle from another perspective;

[0050] Fig. 9 A schematic diagram of the structure of a winding needle provided in some other embodiments of the present application;

[0051] Fig.10 for Fig. 9 A schematic diagram of the structure of the middle winding needle from another perspective;

[0052] Fig.11 A schematic diagram of the structure of a winding device provided in some embodiments of the present application;

[0053] Fig.12 for Fig.11 A schematic structural diagram of the winding device from another perspective;

[0054] Figures 13 to 17 A schematic diagram of the winding process of the present application;

[0055] Fig.18 for Fig.11A schematic structural diagram of a first driving member and a second driving member of a winding device;

[0056] Fig.19 This is a flow chart of a winding method according to some embodiments of the present application.

[0057] Icons: 1-winding needle; 2-winding needle body; 3-first groove; 4-second groove; 5-first area; 6-second area; 7-first plane; 8-first winding needle part; 9-second winding needle part; 10-winding device; 11-first clamping needle; 12-second clamping needle; 13-first wall; 14-heating element; 15-first driving element; 16-second driving element; 100-electrode assembly; 110-positive electrode plate; 120-negative electrode plate; 130-diaphragm; 200-battery cell; 210-casing; 211-shell; 212-end cover; 220-electrode terminal; 300-battery; 310-box; 311-first sub-box; 312-second sub-box; 1000-vehicle; 1100-controller; 1200-motor; X-first direction; Y-second direction. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are 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 those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application 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 drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0060] Reference to "embodiments" in this application 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 in this application may be combined with other embodiments.

[0061] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0062] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can 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 application generally indicates that the associated objects before and after are in an "or" relationship.

[0063] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0064] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0065] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0066] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0067] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0068] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0069] The battery cells may be, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel hydrogen batteries, nickel cadmium batteries, lead storage batteries, etc.

[0070] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, the prismatic battery cell including a square case battery cell.

[0071] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0072] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0073] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0074] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0075] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0076] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0077] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used.

[0078] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0079] As an example, the negative electrode active material may adopt the negative electrode active material for the battery known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials and lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0080] In some embodiments, the separator is a membrane. The present application has no particular limitation on the type of the membrane, and any known porous membrane with good chemical stability and mechanical stability can be selected.

[0081] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0082] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0083] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0084] At present, from the perspective of market development, batteries have been widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as electric tools, drones, energy storage equipment, etc. With the continuous expansion of battery application areas, the market demand is also constantly expanding.

[0085] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, as environmental conditions and / or battery internal conditions change, battery reliability is also one of the key factors to consider.

[0086] At present, the electrode assembly is usually wound by a winding needle, and a groove for accommodating the clamping needle is provided on the winding needle body of the winding needle. After winding, the two clamping needles are accommodated in the groove and the winding needle is pulled away from the electrode assembly, and the two clamping needles are moved away from each other in the horizontal direction to stretch the wound electrode assembly.

[0087] During the stretching process, the electrode assembly is stretched in the horizontal direction, and correspondingly, the upper and lower parts of the electrode assembly in the vertical direction will approach each other, forming a trend that the upper electrode assembly falls and the lower electrode assembly rises. However, due to the effect of gravity, the upper electrode assembly tends to fall faster, which can easily cause the upper electrode assembly to collapse directly, thereby causing the upper electrode assembly to wrinkle. When the tab is located in the upper part, the tab will also fold due to the collapse of the upper electrode assembly. There may be a risk of lithium deposition during the subsequent charging and discharging process, affecting the reliability of the battery cell, thereby affecting the reliability of the battery.

[0088] Based on the above considerations, in order to reduce the risk of collapse and wrinkling of the upper half of the electrode assembly or folding of the tab during the stretching process, resulting in poor reliability of the battery cell and the battery, the embodiment of the present application provides a winding needle, including a winding needle body, a pair of first grooves and a second groove are arranged on the outer circumferential surface of the winding needle body, the pair of first grooves are arranged at intervals along the circumference of the winding needle body, and the second groove and the first groove are arranged at intervals along the circumference of the winding needle body. The first groove is used to accommodate the first clamping needle, and the second groove is used to accommodate the second winding needle.

[0089] By setting the first groove and the second groove, the first groove accommodates the first clamping needle, and the second groove accommodates the second winding needle. In the stretching process of the electrode assembly, the second clamping needle whose position is determined by the second groove abuts against the upper half of the electrode assembly, thereby reducing the descending speed of the upper half, reducing the risk of the upper half collapsing due to the upper half descending too quickly due to gravity and causing wrinkling, and also reduces the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium plating in the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0090] The battery disclosed in the embodiment of the present application can be used in, but not limited to, electrical equipment such as vehicles, ships or aircraft. The battery disclosed in the present application can be used to form a power supply system of the electrical equipment.

[0091] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0092] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device in an embodiment of the present application.

[0093] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 300 is provided inside the vehicle 1000, and the battery 300 may be provided at the bottom, head or tail of the vehicle 1000. The battery 300 may be used to power the vehicle 1000, for example, the battery 300 may be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, for example, for the working power requirements during the startup, navigation and operation of the vehicle 1000.

[0094] The vehicle 1000 may further include a controller 1100 and a motor 1200 , wherein the controller 1100 is used to control the battery 300 to supply power to the motor 1200 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0095] In some embodiments of the present application, the battery 300 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0096] Please refer to Figure 2 , Figure 2 An exploded view of a battery 300 provided in some embodiments of the present application. The battery 300 may also include a box 310, in which the battery cell 200 is accommodated. The box 310 is used to provide a storage space for the battery cell 200, and the box 310 may adopt a variety of structures. In some embodiments, the box 310 may include a first sub-box 311 and a second sub-box 312, the first sub-box 311 and the second sub-box 312 cover each other, and the first sub-box 311 and the second sub-box 312 jointly define a storage space for accommodating the battery cell 200. The second sub-box 312 may be a hollow structure with one end open, and the first sub-box 311 may be a plate-like structure, and the first sub-box 311 covers the open side of the second sub-box 312, so that the first sub-box 311 and the second sub-box 312 jointly define a storage space; the first sub-box 311 and the second sub-box 312 may also be hollow structures both with one side open, and the open side of the first sub-box 311 covers the open side of the second sub-box 312.

[0097] In the battery 300, there may be multiple battery cells 200, and the multiple battery cells 200 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 200 are both connected in series and in parallel. The multiple battery cells 200 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 200 is accommodated in the box 310; of course, the battery 300 may also be a battery 300 module formed by connecting multiple battery cells 200 in series, in parallel, or in a mixed connection, and then the multiple battery 300 modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 310. The battery 300 may also include other structures, for example, the battery 300 may also include a converging component for realizing electrical connection between the multiple battery cells 200.

[0098] The battery cell 200 may be a secondary battery 300 or a primary battery 300 ; the battery cell 200 may also be a lithium-sulfur battery 300 , a sodium-ion battery 300 or a magnesium-ion battery 300 , but is not limited thereto.

[0099] Please refer to Figure 3 , Figure 3 FIG. 2 is an exploded view of a battery cell 200 provided in some embodiments of the present application. Figure 3 As shown, the battery cell 200 includes a housing 210, an electrode assembly 100 and an electrode terminal 220. The housing 210 includes a shell 211 and an end cap 212. The shell 211 has an opening, and the end cap 212 closes the opening to isolate the internal environment of the battery cell 200 from the external environment.

[0100] The shell 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 200, wherein the formed internal environment can be used to accommodate the electrode assembly 100, the electrolyte and other components. The shell 211 and the end cap 212 can be independent components. The shell 211 can be of various shapes and sizes. Specifically, the shape of the shell 211 can be determined according to the specific shape and size of the electrode assembly 100. The material of the shell 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0101] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 200 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 212 is not easily deformed when squeezed and collided, so that the battery cell 200 can have a higher structural strength and reliability can also be improved. Functional components such as electrode terminals can be provided on the end cap 212. The electrode terminal can be used to electrically connect to the electrode assembly 100 for outputting or inputting electrical energy of the battery cell 200. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating structure may be provided inside the end cap 212, and the insulating structure may be used to isolate the electrical connection components in the housing 211 from the end cap 212 to reduce the risk of short circuit. For example, the insulating structure may be plastic, rubber, or the like.

[0102] Please refer to Figure 4 , Figure 4 A schematic diagram of the structure of an electrode assembly provided for some embodiments of the present application. As shown in the figure, the electrode assembly 100 is a component in the battery cell 200 where an electrochemical reaction occurs. One or more electrode assemblies 100 may be included in the housing 211. The electrode assembly 100 is mainly formed by winding or stacking a positive electrode sheet 110 and a negative electrode sheet 120, and a diaphragm 130 is usually provided between the positive electrode sheet 110 and the negative electrode sheet 120, and the diaphragm 130 is used to separate the positive electrode sheet 110 and the negative electrode sheet 120 to reduce the risk of short circuit between the positive electrode sheet 110 and the negative electrode sheet 120. The parts of the positive electrode sheet 110 and the negative electrode sheet 120 with active materials constitute the main body of the electrode assembly 100, and the parts of the positive electrode sheet 110 and the negative electrode sheet 120 without active materials each constitute a pole ear. The positive pole ear and the negative pole ear may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 300 , the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0103] Please refer to Figures 5 to 11 , Figure 5 A schematic diagram of the structure of a winding needle provided in some embodiments of the present application, Figure 6 for Figure 5 A schematic diagram of the structure of the middle winding needle from another perspective. Figure 7 A schematic diagram of the structure of a winding needle provided in some other embodiments of the present application, Figure 8 for Figure 7 A schematic diagram of the structure of the middle winding needle from another perspective. Fig. 9This is a schematic diagram of the structure of the winding needle provided in some embodiments of the present application. Fig.10 for Fig. 9 A schematic diagram of the structure of the middle winding needle from another perspective. Fig.11 A schematic diagram of the structure of a winding device provided in some embodiments of the present application. As shown in the figure, the embodiment of the present application provides a winding needle 1, including a winding needle body 2, a pair of first grooves 3 are arranged on the outer circumference of the winding needle body 2, the first grooves 3 are used to accommodate the first clamping needle 11, and the pair of first grooves 3 are arranged at intervals along the circumference of the winding needle body 2; wherein, at least one second groove 4 is also arranged on the outer circumference of the winding needle body 2, the second groove 4 is used to accommodate the second clamping needle 12, and the second groove 4 and the first groove 3 are arranged at intervals along the circumference of the winding needle body 2.

[0104] In some embodiments, the winding needle 1 is used to wind the positive electrode sheet 110 , the negative electrode sheet 120 and the separator 130 to form the electrode assembly 100 , wherein the electrode assembly 100 can be wound on the outer circumference of the winding needle body 2 .

[0105] In some embodiments, the winding needle body 2 may be a rotating body, which may be a cylinder. The electrode assembly 100 formed by winding the winding needle body 2 has a hollow ring-shaped cross-section in the axial direction of the winding needle body 2, and the electrode assembly 100 includes an inner ring and an outer ring.

[0106] In some embodiments, when the winding needle 1 is wound to form the electrode assembly 100, the winding needle body 2 may be arranged in such a manner that the outer peripheral surface of the winding needle body 2 is arranged horizontally so that the axial direction of the winding needle body 2 is located in the horizontal direction. With the axial direction of the winding needle body 2 as the observation direction, the pair of first grooves 3 are located in the horizontal direction, and in the vertical direction, the second groove 4 is located above the line connecting the pair of first grooves 3.

[0107] After the electrode assembly 100 is formed by winding the outer circumference of the winding needle body 2, a pair of first clamping needles 11 are respectively inserted into the pair of first grooves 3, and a second clamping needle 12 is inserted into the second groove 4. After the winding needle body 2 is taken out from the electrode assembly 100, the pair of first clamping needles 11 are moved away from each other in the horizontal direction, abutted against the inner circle of the electrode assembly 100, and the electrode assembly 100 is stretched in the horizontal direction.

[0108] At the same time, the upper and lower parts of the electrode assembly 100, the upper part, that is, the part of the electrode assembly 100 located above the line connecting the pair of first clamping needles 11 in the vertical direction, and the lower part, that is, the part of the electrode assembly 100 located below the line connecting the pair of first clamping needles 11 in the vertical direction, are close to each other in the vertical direction. Due to the action of gravity, the descending speed of the upper part of the electrode assembly 100 will be greater than the rising speed of the lower part of the electrode assembly 100. The second clamping needle 12 abuts against the upper part of the electrode assembly 100 to reduce the descending speed of the upper part.

[0109] In some embodiments, the number of the second groove 4 may be one.

[0110] In some embodiments, the number of the second grooves 4 can be multiple.

[0111] In some embodiments, the second grooves 4 and the second clamping needles 12 may be arranged in a one-to-one correspondence.

[0112] The technical solution of the embodiment of the present application is to provide a pair of circumferentially spaced first grooves 3 and a second groove 4 different from the first groove 3 on the outer circumferential surface of the winding needle body 2. When in use, the pair of first grooves 3 are provided on both sides in the vertical direction, and the second groove 4 is provided above the line connecting the pair of first grooves 3. The electrode assembly 100 is formed by winding the outer circumferential surface of the winding needle body 2. The first clamping needle 11 is accommodated by the first groove 3, and the second clamping needle 12 is accommodated by the second groove 4, so as to determine the positions of the first clamping needle 11 and the second clamping needle 12. In the subsequent stretching process of the electrode assembly 100, the second clamping needle 12 whose position is determined by the second groove 4 abuts against the upper half of the electrode assembly 100, thereby reducing the descending speed of the upper half and reducing the risk of the upper half collapsing due to the upper half descending too fast due to gravity, thereby causing wrinkling. At the same time, it also reduces the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium deposition in the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0113] Please refer to Figures 5 to 11 In some embodiments, a pair of first grooves 3 are arranged 180° apart along the circumference of the winding needle body 2 .

[0114] In some embodiments, a pair of first grooves 3 can be arranged at 180° intervals along the circumference of the winding needle body 2. When the winding needle body 2 is arranged, the pair of first grooves 3 are located on the same horizontal plane, and the pair of first grooves 3 are located at both ends of the winding needle body 2. A pair of first clamping needles 11 are respectively accommodated in the pair of first grooves 3, and the first clamping needles 11 are far away from each other in the horizontal direction, that is, the pair of first clamping needles 11 respectively abut against the two inner circle walls of the wound electrode assembly 100, and the two inner circle walls are the two inner circle walls corresponding to the diameter of the electrode assembly 100 in the horizontal direction.

[0115] In some embodiments, a pair of first grooves 3 are arranged at 180° intervals along the circumference of the winding needle body 2, that is, with the axial direction of the winding needle body 2 as the observation direction, on the axial surface of the winding needle body 2, a pair of first grooves 3 can be arranged on the same horizontal plane.

[0116] In some embodiments, due to processing errors and other reasons, the angle at which the pair of first grooves 3 are spaced apart along the circumference of the winding needle body 2 may also be between 170° and 180°, for example, 170°, 171°, 172°, 173°, 174°, 175°, 176°, 177°, 178°, 179°, 180°, etc. When the angle setting between the pair of first grooves 3 is affected by processing errors, when setting the pair of first grooves 3, with the axial direction of the winding needle body 2 as the observation direction, on the surface of the winding needle body 2 in the axial direction, the pair of grooves are set to be symmetrical with respect to the diameter of the electrode assembly 100 in the vertical direction.

[0117] The technical solution of the embodiment of the present application is to set a pair of first grooves 3 at an interval of 180° on the outer circumferential surface of the winding needle body 2, wherein the electrode assembly 100 is formed by winding the outer circumferential surface of the winding needle body 2, and the pair of first grooves 3 are set on both sides in the vertical direction, that is, the pair of first grooves 3 are located on the diameter of the electrode assembly 100 in the horizontal direction, and the first grooves 3 are used to accommodate the first clamping needles 11. In the subsequent stretching process of the electrode assembly 100, the first clamping needles 11 are separated from each other in the horizontal direction, which can achieve the best stretching effect of the electrode assembly 100 and facilitate the setting of the second grooves 4, thereby improving convenience.

[0118] Please refer to Figures 5 to 11 In some embodiments, in the circumferential direction of the winding needle body 2, the angle between the second groove 4 and one of the first grooves 3 is α, which satisfies: 45°≤α≤90°.

[0119] In some embodiments, on the circumference of the winding needle body 2, the angle between the second groove 4 and one of the first grooves 3 can be α, at this time, the angle between the second groove 4 and the other first groove 3 can be 180°-α, α satisfies 45°≤α≤90°, where α can be 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc.

[0120] In some embodiments, the angle α can be measured in the following manner: With the axial direction of the winding needle body 2 as the observation direction, on the axial surface of the winding needle body 2, taking one of the first grooves 3 as an example, the angle between the extension line of the wall of one of the first grooves 3 away from the second groove 4 and the extension line of the wall of the second groove 4 close to the first groove 3 is α.

[0121] In the technical solution of the embodiment of the present application, the angle between the second groove 4 and one of the first grooves 3 is α, and when in use, a pair of first grooves 3 are arranged horizontally, and the second groove 4 is arranged above the first groove 3, and the first groove 3 is used to accommodate the first clamping needle 11, and the second groove 4 is used to accommodate the second clamping needle 12. The size of α corresponds to the position of the second clamping needle 12 corresponding to the wound electrode assembly 100. When 45°≤α≤90°, that is, the first clamping needle 11 and the second clamping needle 12 are far apart, that is, the height of the second clamping needle 12 in the vertical direction is higher, and the second clamping needle 12 abuts The upper part of the electrode assembly 100 is closer to the upper end of the electrode assembly 100 and has a smaller angle away from the upper end of the electrode assembly 100. The second clamping needle 12 abuts against the upper part of the electrode assembly 100, which reduces the descending speed of the upper part of the electrode assembly 100 and reduces the risk of the upper part collapsing and wrinkling due to the upper part falling too quickly due to gravity. It also reduces the probability of the pole ear folding when it is located in the upper part, thereby reducing the risk of lithium deposition in the electrode assembly 100 and improving the reliability of the battery cell 200, thereby improving the reliability of the battery 300.

[0122] In some embodiments, 60°≤α≤90°.

[0123] In some embodiments, the angle between the second groove 4 and one of the first grooves 3 can be α, at which time the angle between the second groove 4 and the other first groove 3 can be 180°-α, and α satisfies 60°≤α≤90°, wherein α can be 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc.

[0124] According to the technical solution of the embodiment of the present application, when 60°≤α≤90°, that is, the first clamping needle 11 and the second clamping needle 12 are farther apart, the second clamping needle 12 is closer to the upper end of the electrode assembly 100, and the angle of deviation from the upper end of the electrode assembly 100 is smaller, and the second clamping needle 12 abuts against the upper half of the electrode assembly 100, thereby reducing the descending speed of the upper half of the electrode assembly 100, and reducing the risk of the upper half collapsing and wrinkling due to the upper half descending too quickly due to gravity, and also reducing the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium plating of the electrode assembly 100, and improving the reliability of the battery cell 200, thereby improving the reliability of the battery 300.

[0125] In some embodiments, 85°≤α≤90°.

[0126] In some embodiments, the angle between the second groove 4 and one of the first grooves 3 can be α, at which time the angle between the second groove 4 and the other first groove 3 can be 180°-α, and α satisfies 85°≤α≤90°, where α can be 85°, 86°, 87°, 88°, 89°, 90°, etc.

[0127] In some embodiments, the number of the second groove 4 may be one, and α may be 90°.

[0128] According to the technical solution of the embodiment of the present application, when 85°≤α≤90°, that is, the second clamping needle 12 abuts against the uppermost end of the electrode assembly 100, and deviates from the uppermost end of the electrode assembly 100 due to positioning error or process reasons, the second clamping needle 12 abuts against the upper half of the electrode assembly 100, thereby reducing the descending speed of the upper half of the electrode assembly 100, and reducing the risk of the upper half collapsing and wrinkling due to the upper half descending too quickly due to gravity, and also reducing the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium deposition of the electrode assembly 100, and improving the reliability of the battery cell 200, thereby improving the reliability of the battery 300.

[0129] Please refer to Figure 8 In some embodiments, the outer circumference of the winding needle body 2 is divided into a first area 5 and a second area 6 by a pair of first grooves 3 , and there are multiple second grooves 4 , which are all arranged in the first area 5 .

[0130] In some embodiments, there is no special distinguishing mark between the first area 5 and the second area 6 , and the area where the second groove 4 is provided may be the first area 5 .

[0131] In some embodiments, the plurality of second grooves 4 may all be disposed in the second region 6 , and no second grooves 4 may be disposed in the first region 5 .

[0132] According to the technical solution of the embodiment of the present application, under the action of gravity, only the upper half of the electrode assembly 100 will collapse due to the rapid descent, thereby causing the pole piece or pole ear of the upper half to wrinkle, that is, only the upper half of the electrode assembly 100 needs to be abutted and supported. The outer peripheral surface of the winding needle body 2 is divided into a first area 5 and a second area 6 by a pair of first grooves 3, and a plurality of second grooves 4 are all arranged in the first area 5. At the same time, when in use, the pair of first grooves 3 are arranged in the horizontal direction, and the second grooves 4 of the first area 5 are arranged above the pair of first grooves 3. The second grooves 4 are used to accommodate the second clamping needle 12. The second clamping needle 12 abuts against the upper half of the electrode assembly 100, thereby reducing the descending speed of the upper half of the electrode assembly 100, reducing the risk of the upper half collapsing due to the rapid descent of the upper half due to the action of gravity, thereby causing wrinkles, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium deposition of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300. By setting the second groove 4 in the first area 5 and setting the first area 5 above the first groove 3 when in use, the probability of setting the second clamping needle 12 below the first groove 3 when setting the second clamping needle 12 is reduced, while also saving costs and improving installation convenience.

[0133] Please refer to Figures 5 to 11 In some embodiments, a pair of first grooves 3 are symmetrically arranged relative to the first plane 7 , the central axis of the winding needle body 2 is located on the first plane 7 , and there are multiple second grooves 4 , which are symmetrically arranged relative to the first plane 7 .

[0134] Please refer to Figures 9 and 10 In some embodiments, the number of the second grooves 4 can be an even number, and the outer peripheral surface of the winding needle body 2 is horizontally arranged so that the axial direction of the winding needle body 2 is located in the horizontal direction. Taking the axial direction of the winding needle body 2 as the observation direction, a pair of first grooves 3 are located in the horizontal direction and are symmetrically arranged relative to the first plane 7. The even number of second grooves 4 are all located above the pair of first grooves 3, and the even number of second grooves 4 are symmetrically arranged relative to the first plane 7.

[0135] Please refer to Figures 7 and 8 In some embodiments, the number of the second grooves 4 can be an odd number greater than one, and the outer peripheral surface of the winding needle body 2 is horizontally arranged so that the axial direction of the winding needle body 2 is located in the horizontal direction. With the axial direction of the winding needle body 2 as the observation direction, a pair of first grooves 3 are located in the horizontal direction and are symmetrically arranged relative to the first plane 7. The even-numbered second grooves 4 are all located above the pair of first grooves 3. One second groove 4 can be arranged on the first plane 7, and the remaining even-numbered second grooves 4 are symmetrically arranged relative to the first plane 7.

[0136] The technical solution of the embodiment of the present application is to arrange multiple second grooves 4 symmetrically relative to the first plane 7, and the central axis of the winding needle body 2 is located on the first plane 7, that is, when in use, a pair of first grooves 3 are arranged in the horizontal direction, and the electrode assembly 100 is formed by winding the outer peripheral surface of the winding needle body 2, and the second grooves 4 are symmetrically arranged relative to the diameter of the electrode assembly 100 in the vertical direction, and the second clamping needles 12 are accommodated in the second grooves 4, so that the multiple second clamping needles 12 respectively abut the parts of the electrode assembly 100 on both sides of the diameter in the vertical direction, so that the abutting effect of the second clamping needles 12 located on both sides of the diameter of the electrode assembly 100 in the vertical direction is symmetrical, thereby reducing the descending speed of the upper half of the electrode assembly 100, and reducing the risk of the upper half collapsing due to the upper half descending too fast due to gravity, thereby causing wrinkling, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium deposition in the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0137] Please refer to Figures 5 to 11 In some embodiments, the first groove 3 and the second groove 4 both penetrate the winding needle body 2 along the axial direction of the winding needle body 2 .

[0138] In some embodiments, the first clamping needle 11 can be accommodated in the first groove 3, the second clamping needle 12 can be accommodated in the second groove 4, the length of the first clamping needle 11 can be greater than the axial length of the first groove 3 in the winding needle body 2, and the length of the second clamping needle 12 can be greater than the axial length of the second groove 4 in the winding needle body 2.

[0139] In some embodiments, both the first groove 3 and the second groove 4 penetrate the winding needle body 2 along the axial direction of the winding needle body 2. The first clamping needle 11 can be accommodated in the first groove 3, and both ends of the first clamping needle 11 can pass through the first groove 3, or one end of the first clamping needle 11 can pass through the first groove 3 and the other end can be accommodated in the first groove 3; the second clamping needle 12 can be accommodated in the second groove 4, and both ends of the second clamping needle 12 can pass through the second groove 4, or one end of the second clamping needle 12 can pass through the second groove 4 and the other end can be accommodated in the second groove 4.

[0140] In some embodiments, the first groove 3 and the second groove 4 may not penetrate the winding needle body 2 along the axial direction of the winding needle body 2. One end of the first clamping needle 11 may abut against the wall surface of the first groove 3 in the axial direction of the winding needle body 2, and the other end may pass through the first groove 3; one end of the second clamping needle 12 may abut against the wall surface of the second groove 4 in the axial direction of the winding needle body 2, and the other end may pass through the second groove 4.

[0141] According to the technical solution of the embodiment of the present application, the first groove 3 and the second groove 4 extend along the axial direction of the winding needle body 2 and penetrate the winding needle body 2, the first groove 3 is used to accommodate the first clamping needle 11, and the second groove 4 is used to accommodate the second clamping needle 12, which improves the convenience of the first clamping needle 11 and the second clamping needle 12 during the installation process. By determining the positions of the first groove 3 and the second groove 4, the positions of the first clamping needle 11 and the second clamping needle 12 are determined, which improves the accuracy of the installation positions of the first clamping needle 11 and the second clamping needle 12, and also facilitates the removal of the winding needle 1, reducing the risk of interference between the winding needle 1 and the first clamping needle 11 and the second clamping needle 12 during the removal process.

[0142] Please refer to Figures 5 to 11 In some embodiments, the needle winding body 2 includes a first needle winding portion 8 and a second needle winding portion 9, a gap is defined between the first needle winding portion 8 and the second needle winding portion 9, the second groove 4 and one of the first grooves 3 are arranged on the outer circumferential surface of the first needle winding portion 8, and the other first groove 3 is arranged on the outer circumferential surface of the second needle winding portion 9.

[0143] The technical solution of the embodiment of the present application is that the first winding needle part 8 and the second winding needle part 9 form a winding needle body 2, and the first winding needle part 8 and the second winding needle part 9 define a gap, wherein one first groove 3 is set in the first winding needle part 8, and the other first groove 3 is set in the second winding needle part 9. Therefore, when using the winding needle 1, the size of the gap can be changed by moving the first winding needle part 8 and the second winding needle part 9, thereby changing the relative position of the first winding needle part 8 and the second winding needle part 9, thereby realizing fine adjustment of a pair of first grooves 3 during setting. By accommodating the first clamping needle 11 by the first groove 3, the accuracy of the installation position of the first clamping needle 11 is improved, thereby improving the stretching effect of the electrode assembly 100, improving the reliability of the electrode assembly 100, and improving the reliability of the battery cell 200 and the battery 300.

[0144] Please refer to Figures 11 to 18 . Fig.12 for Fig.11 A schematic diagram of the structure of the winding device from another perspective. Figures 13 to 17 This is a schematic diagram of the winding process of this application. Fig.18 for Fig.11 A schematic diagram of the structure of the first driving member and the second driving member of the winding device, Fig.19Flow chart of the winding method of some embodiments of the present application. As shown in the figure, in the second aspect, the present application further provides a winding device 10 for winding an electrode assembly 100, comprising a winding needle 1 as in any embodiment of the first aspect, a pair of first clamping needles 11 and at least one second clamping needle 12, wherein the pair of first clamping needles 11 are configured to move away from each other after the winding needle 1 is withdrawn from the electrode assembly 100 to open the electrode assembly 100, and the second clamping needle 12 is configured to support the upper half of the electrode assembly 100 during the process of the pair of first clamping needles 11 opening the electrode assembly 100.

[0145] Please refer to Figure 5 to Figure 6 In some embodiments, the winding needle 1 includes a winding needle body 2, on the outer circumference of the winding needle body 2, a pair of first grooves 3 can be arranged at intervals of 180° along the circumference of the winding needle body 2, and a second groove 4 is also arranged on the outer circumference. Fig.13 , the electrode assembly 100 is wound on the outer circumference of the winding needle body 2, please refer to Fig.14 , place a pair of first clamping pins 11 in a pair of first grooves 3 respectively, place the second clamping pin 12 in the second groove 4, and pull the winding pin 1 out of the electrode assembly 100. With the axial direction of the winding pin body 2 as the observation direction, at this time, the pair of first clamping pins 11 are located in the same horizontal direction, and the second clamping pin 12 is located above the first clamping pin 11 and on the first plane 7. Please refer to Figures 15 to 17 , move a pair of first clamping needles 11 away from each other in the horizontal direction, and respectively abut against the inner circle parts corresponding to the inner diameter of the electrode assembly 100 in the horizontal direction, and stretch the electrode assembly 100 in the horizontal direction. The second clamping needles 12 abut against the inner circle parts corresponding to the inner diameter of the electrode assembly 100 in the vertical direction, and support the upper half of the electrode assembly 100 to reduce the descending speed of the upper half during the stretching process.

[0146] The technical solution of the embodiment of the present application is to set the first clamping needle 11 in the first groove 3, and the second clamping needle 12 in the second groove 4. After the electrode assembly 100 is wound and formed, the winding needle 1 is taken out, and the two first clamping needles 11 move away from each other in the horizontal direction and abut against the two inner walls of the electrode assembly 100 opposite to each other in the horizontal direction to stretch the electrode assembly 100 in the horizontal direction. At this time, the two inner walls of the electrode assembly 100 opposite to each other in the vertical direction are close to each other, and the second clamping needle 12 abuts against the upper half of the electrode assembly 100, reducing the descending speed of the upper half, reducing the risk of the upper half collapsing due to the upper half descending too fast due to gravity, thereby causing wrinkling, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium plating of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0147] Please refer to Fig.13 In some embodiments, the second clamping needle 12 has a first wall surface 13 away from the central axis of the winding needle body 2, and the first wall surface 13 is configured as an arc surface.

[0148] In some embodiments, when the second clamping needle 12 is accommodated in the second groove 4 , the wall away from the central axis of the winding needle body 2 is the first wall 13 , wherein the first wall 13 may be an arc surface that protrudes away from the central axis of the winding needle body 2 .

[0149] The technical solution of the embodiment of the present application is that the second clamping needle 12 abuts the upper half of the electrode assembly 100, and the second clamping needle 12 has a first wall 13 away from the central axis of the winding needle body 2, and the first wall 13 abutting the upper half of the electrode assembly 100 is an arc surface. Since the electrode assembly 100 after winding is annular and the inner wall of the electrode assembly 100 is an arc surface, the first wall 13 is constructed as an arc surface, which can make the second clamping needle 12 abut the upper half of the electrode assembly 100 more smooth, thereby reducing the risk of damaging the electrode assembly 100, thereby improving the reliability of the battery 300.

[0150] Please refer to Fig.15 In some embodiments, the winding device 10 further includes a heating element 14 , which is connected to the second clamping needle 12 to heat the second clamping needle 12 .

[0151] In some embodiments, the heating element 14 may be in direct contact with the second clamping needle 12 to achieve heat conduction.

[0152] In some embodiments, the heating element 14 may not be in direct contact with the second clamping needle 12 , and only needs to form a thermally conductive connection that enables heat exchange.

[0153] The technical solution of the embodiment of the present application is to set a heating element 14 connected to the second clamping needle 12 for heating the second clamping needle 12, wherein the second clamping needle 12 is used to abut the upper half of the electrode assembly 100, and the upper half includes a positive electrode sheet, a negative electrode sheet and a diaphragm 130 for bonding the positive and negative electrode sheets. The second clamping needle 12 is heated to melt the adhesive of the diaphragm 130 in the upper half, thereby making the bonding between the diaphragm 130 and the positive and negative electrode sheets stronger, reducing the risk of wrinkling the electrode sheets, and improving the reliability of the electrode assembly 100, thereby improving the reliability of the battery 300.

[0154] In some embodiments, the heating element 14 is a resistive element.

[0155] The technical solution of the embodiment of the present application sets the heating element 14 as a resistance element, which is easy to obtain and easy to achieve the heating effect, thereby improving the convenience of heating.

[0156] Please refer to Fig.18 In some embodiments, the winding device 10 also includes a first driving member 15 and a second driving member 16, the first driving member 15 is connected to a pair of first clamping needles 11 to drive the pair of first clamping needles 11 away from each other along a first direction X, and the second driving member 16 is connected to the second clamping needle 12 to drive the second clamping needle 12 to move along a second direction Y, wherein the first direction X and the second direction Y intersect.

[0157] In some embodiments, the first driving member 15 may include two driving arms, the two driving arms are respectively connected to a pair of first clamping needles 11, and drive the pair of first clamping needles 11 away from each other along the first direction X, and the second driving member 16 is connected to the second clamping needle 12 to drive the second clamping needle 12 to move along the second direction Y. It should be noted that, with the axial direction of the winding needle body 2 as the observation direction, the first direction X can be a horizontal direction, and the second direction Y can be a vertical direction. That is, the first driving member 15 drives the pair of first clamping needles 11 away from each other in the horizontal direction, and the second driving member 16 drives the second clamping needle 12 to move downward in the vertical direction until the pair of first clamping needles 11 and the second clamping needle 12 are located in the same horizontal direction.

[0158] As shown in the figure, the first direction X can be represented by X, and the second direction Y can be represented by Y.

[0159] The technical solution of the embodiment of the present application is to drive a pair of first clamping needles 11 away from each other along the first direction X by setting a first driving member 15 connected to the first clamping needle 11, and to drive a pair of first clamping needles 11 away from each other along the first direction X, and to drive a second driving member 16 to drive the second clamping needle 12 to move downward along the second direction Y, so that the two first clamping needles 11 move away from each other along the first direction X, and abut against two inner walls of the electrode assembly 100 opposite to each other in the first direction X, so as to stretch the electrode assembly 100 along the first direction X, so that the second clamping needle 12 moves downward in the second direction Y, and abuts against the upper half of the electrode assembly 100 during the movement, thereby reducing the descending speed of the upper half, reducing the risk of the upper half collapsing due to the upper half falling too fast due to gravity, and causing wrinkles, and also reducing the probability of the tab folding when the tab is located in the upper half, thereby reducing the risk of lithium deposition of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300. In addition, through mechanized driving, it is convenient to control the speed of the first clamping needle 11 and the second clamping needle 12, and the convenience of operation is also improved.

[0160] In a third aspect, an embodiment of the present application further provides a battery 300 manufacturing device, comprising a winding device 10 as in any one of the embodiments of the second aspect.

[0161] According to the technical solution of the embodiment of the present application, the winding of the electrode assembly 100 is completed by a winding device 10, and then the battery 300 or the battery cell 200 is manufactured by a battery 300 manufacturing device. Among them, the winding device 10 includes a winding needle 1, a first clamping needle 11 and a second clamping needle 12. The first clamping needle 11 is set in the first groove 3 of the winding needle 1, and the second clamping needle 12 is set in the second groove 4 of the winding needle 1. After the winding needle 1 winds the electrode assembly 100 into shape, it is taken out, and the two first clamping needles 11 move away from each other in the horizontal direction and abut against the two inner walls of the electrode assembly 100 opposite to each other in the horizontal direction to stretch the electrode assembly 100 in the horizontal direction. At this time, the two inner walls of the electrode assembly 100 opposite to each other in the vertical direction are close to each other, and the second clamping needle 12 abuts against the upper half of the electrode assembly 100, reducing the descending speed of the upper half, reducing the risk of the upper half collapsing due to the upper half descending too fast due to gravity, thereby causing wrinkling, and also reducing the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium precipitation of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0162] Please refer to Figures 5 to 19 , Fig.19 Flow chart of the winding method of some embodiments of the present application. As shown in the figure, in the fourth aspect, the embodiments of the present application also provide a winding method, including: S100 providing a winding needle 1 as in any embodiment of the first aspect. Please refer to Fig.13 , S200 winding needle 1 winds the electrode sheet and the separator 130 to form the electrode assembly 100. Please refer to Fig.14 , S300 inserts a pair of first clamping needles 11 into a pair of first grooves 3, and inserts a second clamping needle 12 into a second groove 4. Please refer to Fig.15 , S400 removes the winding needle 1 from the electrode assembly 100. Please refer to Figure 16 to Figure 17 S500 moves the pair of first clamping needles 11 away from each other to open the electrode assembly 100. S600 supports the upper half of the electrode assembly 100 by the second clamping needles 12 during the process of opening the electrode assembly 100.

[0163] The technical solution of the embodiment of the present application is to wind the positive and negative electrode sheets and the separator 130 to form the electrode assembly 100 through the provided winding needle 1, and then insert the first clamping needle 11 into the first groove 3 of the winding needle 1, and insert the second clamping needle 12 into the second groove 4 of the winding needle 1 to form a winding device 10, and then pull the winding needle 1 out of the electrode assembly 100, so that the first clamping needle 11 and the second clamping needle 12 can move. At this time, a pair of first clamping needles 11 are moved away from each other, abutting against the two inner walls opposite to the electrode assembly 100 while propping up the electrode assembly 100 to achieve stretching of the electrode assembly 100. At the same time, the second clamping needle 12 supports the upper half of the electrode assembly 100, reduces the descending speed of the upper half, reduces the risk of the upper half collapsing due to the rapid descent of the upper half due to gravity, and thus causes wrinkling, and also reduces the probability of the pole ear folding when the pole ear is located in the upper half, thereby reducing the risk of lithium deposition in the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0164] In some embodiments, the upper half of the electrode assembly 100 is supported by the second clamping needle 12 so that the movement speed of the area where the upper half contacts the second clamping needle 12 is less than or equal to the movement speed of the area where the lower half of the electrode assembly 100 faces the second clamping needle 12.

[0165] The technical solution of the embodiment of the present application supports the upper half of the electrode assembly 100 by the second clamping needle 12, reduces the descending speed of the upper half, and makes the moving speed of the contact area of ​​the upper half and the second clamping needle 12 less than or equal to the moving speed of the area of ​​the lower half of the electrode assembly 100 directly facing the second clamping needle 12. By comparing the speeds, it is confirmed that the second clamping needle 12 reduces the risk of the upper half collapsing and wrinkling due to the upper half descending too quickly due to gravity, and also reduces the probability of the pole ear folding when it is located in the upper half, thereby reducing the risk of lithium deposition of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0166] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A needle coil, characterized in that: It comprises a winding needle body, wherein a pair of first grooves are arranged on the outer circumferential surface of the winding needle body, wherein the first grooves are used to accommodate the first clamping needle, and the pair of first grooves are arranged at intervals along the circumferential direction of the winding needle body; Wherein, at least one second groove is further arranged on the outer circumferential surface of the winding needle body, the second groove is used to accommodate the second clamping needle, and the second groove and the first groove are arranged at intervals along the circumferential direction of the winding needle body.

2. The winding needle according to claim 1, characterized in that: The pair of first grooves are arranged at intervals of 180° along the circumference of the winding needle body.

3. The winding needle according to claim 2, characterized in that: In the circumferential direction of the winding needle body, the angle between the second groove and one of the first grooves is α, which satisfies: 45°≤α≤90°.

4. The winding needle according to claim 3, characterized in that: 60°≤α≤90°。 5. The winding needle according to claim 4, characterized in that: 85°≤α≤90°。 6. The winding needle according to claim 2, characterized in that: The outer circumferential surface of the winding needle body is divided into a first area and a second area by the pair of first grooves. There are a plurality of second grooves, and the plurality of second grooves are all arranged in the first area.

7. The winding needle according to claim 2, characterized in that: The pair of first grooves are symmetrically arranged relative to a first plane, the central axis of the winding needle body is located on the first plane, and there are a plurality of second grooves, which are symmetrically arranged relative to the first plane.

8. The winding needle according to claim 1, characterized in that: The first groove and the second groove both penetrate the winding needle body along the axial direction of the winding needle body.

9. The winding needle according to claim 1, characterized in that: The needle winding body includes a first needle winding part and a second needle winding part, a gap is defined between the first needle winding part and the second needle winding part, the second groove and one of the first grooves are arranged on the outer circumferential surface of the first needle winding part, and the other first groove is arranged on the outer circumferential surface of the second needle winding part.

10. A winding device for winding an electrode assembly, characterized in that: include: The winding needle according to any one of claims 1 to 9; a pair of first clamping needles, wherein the pair of first clamping needles are configured to move away from each other after the winding needle is pulled away from the electrode assembly, so as to open the electrode assembly; At least one second clamping needle, wherein the second clamping needle is configured to support the upper half of the electrode assembly during the process of the pair of first clamping needles spreading the electrode assembly.

11. The winding device according to claim 10, characterized in that The second clamping needle has a first wall surface away from the central axis of the winding needle body, and the first wall surface is configured as an arc surface.

12. The winding device according to claim 10, characterized in that The winding device further comprises a heating element, and the heating element is connected to the second clamping needle to heat the second clamping needle.

13. The winding device according to claim 12, characterized in that The heating element is a resistance element.

14. The winding device according to claim 10, characterized in that The winding device also includes a first driving member and a second driving member, wherein the first driving member is connected to the pair of first clamping needles to drive the pair of first clamping needles away from each other in a first direction, and the second driving member is connected to the second clamping needle to drive the second clamping needle to move in a second direction, wherein the first direction and the second direction intersect.

15. A battery manufacturing device, characterized in that: Comprising a winding device as claimed in any one of claims 10 to 14.

16. A winding method, characterized in that: include: Providing a winding needle as claimed in any one of claims 1 to 9; The winding needle winds the pole piece and the diaphragm to form an electrode assembly; Inserting a pair of first clamping needles into the pair of first grooves, and inserting a second clamping needle into the second groove; Pulling the winding needle away from the electrode assembly; The pair of first clamping needles are moved in a direction away from each other to spread the electrode assembly; in the process of spreading the electrode assembly, the upper half of the electrode assembly is supported by the second clamping needles.

17. The winding method according to claim 16, characterized in that: The upper part of the electrode assembly is supported by the second clamping needle so that the movement speed of the area where the upper part contacts the second clamping needle is less than or equal to the movement speed of the area where the lower part of the electrode assembly faces the second clamping needle.

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