Winding needle, winding apparatus, battery manufacturing apparatus, and winding method

Abstract

Embodiments of the present application provide a winding needle, a winding apparatus, a battery manufacturing apparatus, and a winding method. The winding apparatus 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 directions to be away from each other when the winding needle is pulled away from an electrode assembly, so as to open the electrode assembly; the second clamping needle is configured to support the upper half part of the electrode assembly in the process of the pair of first clamping needles opening the electrode assembly. The winding needle comprises a winding needle body; a pair of first grooves are formed on the outer circumferential surface of the winding needle body; the first grooves are used for accommodating the first clamping needles; the pair of first grooves are arranged at an interval in the circumferential direction of the winding needle body; at least one second groove is further formed on the outer circumferential surface of the winding needle body; the second groove is used for accommodating the second clamping needle; the second groove and the first grooves are arranged at intervals in the circumferential direction of the winding needle body. The technical solution provided by the present application can improve the reliability of a battery.

Description

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202310807055.2, filed on July 3, 2023, entitled “Winding needle, winding device, battery manufacturing equipment and winding method,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery production technology, and in particular to a winding needle, a winding device, a battery manufacturing equipment and a winding method. Background Art

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. Electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the sustainable development of the automotive industry. For electric vehicles, battery technology is a key factor in their development.

[0005] In the development of battery technology, how to improve battery reliability is a technical problem that needs to be solved urgently.

[0006] Summary of the Invention

[0007] 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.

[0008] This application is achieved through the following technical solutions:

[0009] In the first aspect, the present application provides a winding needle, including a winding needle body, a pair of first grooves are provided 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 provided 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.

[0010] 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 provided on both sides in the vertical direction, and the second groove is provided 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, 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, and causing wrinkling. At the same time, it 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.

[0011] In some embodiments, a pair of first grooves are arranged 180° apart along the circumference of the winding needle body.

[0012] 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 grooves are used to accommodate the first clamping needles. 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.

[0013] 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, which satisfies: 45°≤α≤90°.

[0014] 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 where the second clamping needle abuts is closer to the upper end of the electrode assembly, and the angle away 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 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.

[0015] In some embodiments, 60°≤α≤90°.

[0016] 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. 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 due to gravity, and thus 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.

[0017] In some embodiments, 85°≤α≤90°.

[0018] 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 due to gravity, and thus 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.

[0019] In some embodiments, the outer circumference of the winding needle body is divided into a first area and a second area by a pair of first grooves. There are multiple second grooves, and the multiple second grooves are all arranged in the first area.

[0020] 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 falling too fast, thereby causing the pole piece or pole ear in the upper half to wrinkle, that is, only the upper half of the electrode assembly needs to be abutted and supported. 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 falling too fast 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. 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.

[0021] 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.

[0022] 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 effects of the second clamping needles located on both sides of the diameter of the electrode assembly in the vertical direction are symmetrical, 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 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.

[0023] 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.

[0024] 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 pass through 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.

[0025] In some embodiments, the winding needle body includes a first winding needle portion and a second winding needle portion, a gap is defined between the first winding needle portion and the second winding needle portion, the second groove and one of the first grooves are arranged on the outer peripheral surface of the first winding needle portion, and the other first groove is arranged on the outer peripheral surface of the second winding needle portion.

[0026] 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 set on the first winding needle part, and the other first groove is set 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.

[0027] 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.

[0028] 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. The winding needle takes out the electrode assembly after winding it into shape, 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 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, 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 it is 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.

[0029] 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.

[0030] 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 and the inner wall of the electrode assembly is an arc surface, 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.

[0031] In some embodiments, the winding device further includes a heating element connected to the second clamping needle to heat the second clamping needle.

[0032] 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, and the upper half includes a positive electrode sheet, a negative electrode sheet and a diaphragm for bonding the positive and negative electrode sheets. 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, improving the reliability of the electrode assembly, and thus improving the reliability of the battery.

[0033] In some embodiments, the heating element is a resistive element.

[0034] 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 a heating effect, thereby improving the convenience of heating.

[0035] In some embodiments, the winding device further includes a first driving member and a second driving member, the first driving member being connected to a pair of first clamping needles to drive a pair of first clamping needles away from each other along a first direction, and the second driving member being 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.

[0036] The technical solution of the embodiment of the present application is to set a first driving member connected to the first clamping pin to drive a pair of first clamping pins away from each other in the first direction, and set a second driving member to drive the second clamping pin to move downward in the second direction, so that the two first clamping pins move away from each other in the first direction and abut against the two inner walls of the electrode assembly opposite to each other in the first direction to stretch the electrode assembly in the first direction, so that the second clamping pin moves downward in the second direction, and abuts against the upper half of the electrode assembly during the movement, 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, thereby causing wrinkling, and also reducing the probability of the tab folding when the tab is 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. In addition, through mechanized drive, it is easy to control the speed of the first clamping pin and the second clamping pin, which also improves the convenience of operation.

[0037] 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.

[0038] 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. 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 winding needle winds the electrode assembly, it is taken out. 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 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 in the vertical direction are close to each other. The second clamping needle abuts against the upper half of the electrode assembly, 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, thereby causing wrinkling. At the same time, it also reduces the probability of the tab folding when the tab 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.

[0039] 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 electrode sheet 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.

[0040] 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 through the provided winding needle, and 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 stretching 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, and reduces the risk of the upper half collapsing due to the rapid descent of gravity, thereby causing wrinkling. At the same time, it 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.

[0041] In some embodiments, the upper half of the electrode assembly is supported by the 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.

[0042] The technical solution of the embodiment of the present application supports the upper half of the electrode assembly by the second clamping needle, 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 less than or equal to the moving speed of the area of ​​the lower half of the electrode assembly facing the second clamping needle. By comparing the speeds, it is confirmed that the second clamping needle reduces the risk of the upper half collapsing and wrinkling due to the upper half falling 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 plating of the electrode assembly, improving the reliability of the battery cell, and thus improving the reliability of the battery.

[0043] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 relevant drawings can be obtained based on these drawings without creative work.

[0045] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0046] FIG2 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0047] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0048] FIG4 is a schematic structural diagram of an electrode assembly provided in some embodiments of the present application;

[0049] FIG5 is a schematic diagram of the structure of a winding needle provided in some embodiments of the present application;

[0050] FIG6 is a schematic structural diagram of the winding needle in FIG5 from another perspective;

[0051] FIG7 is a schematic structural diagram of a winding needle provided in other embodiments of the present application;

[0052] FIG8 is a schematic structural diagram of the winding needle in FIG7 from another perspective;

[0053] FIG9 is a schematic structural diagram of a winding needle provided in some other embodiments of the present application;

[0054] FIG10 is a schematic structural diagram of the winding needle in FIG9 from another perspective;

[0055] FIG11 is a schematic structural diagram of a winding device provided in some embodiments of the present application;

[0056] FIG12 is a schematic structural diagram of the winding device in FIG11 from another perspective;

[0057] 13 to 17 are schematic diagrams of the process of the winding method of the present application;

[0058] FIG18 is a schematic structural diagram of the first driving member and the second driving member of the winding device in FIG11;

[0059] FIG19 is a flow chart of a winding method according to some embodiments of the present application.

[0060] 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

[0061] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0062] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. 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" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" 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-secondary relationship.

[0063] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0064] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0065] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0066] The term "multiple" in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0067] 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.

[0068] 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 housed in the case.

[0069] 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.

[0070] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0071] 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.

[0072] 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-acid batteries, and the like.

[0073] 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 another shape, wherein the prismatic battery cell includes a square-cased battery cell.

[0074] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0075] In some embodiments, the positive electrode may be a positive electrode sheet, which 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.

[0076] 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 provided on either or both of the two facing surfaces of the positive electrode current collector.

[0077] 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 layer 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.).

[0078] 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.

[0079] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0080] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, the metal foil may be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium.

[0081] In some embodiments, the negative electrode current collector has two opposite surfaces in its thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0082] As an example, the negative electrode active material may be a negative electrode active material for a battery that is well 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, 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.

[0083] 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 and mechanical stability can be selected.

[0084] As an example, the primary 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 particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0085] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0086] 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.

[0087] Currently, based on market developments, batteries are widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in power tools, drones, energy storage devices, and other fields. As the application areas of batteries continue to expand, market demand is also growing.

[0088] The development of battery technology must consider multiple design factors simultaneously, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, as environmental conditions and / or internal conditions of the battery change, battery reliability is also one of the key factors to consider.

[0089] Currently, electrode assemblies are typically wound using a winding needle. The winding needle body is provided with grooves for accommodating the clamping pins. After winding, the two clamping pins are placed in the grooves and the winding needle is removed from the electrode assembly, moving the two clamping pins horizontally away from each other to stretch the wound electrode assembly.

[0090] During the stretching process, the electrode assembly is stretched horizontally, and correspondingly, the upper and lower portions of the electrode assembly, which are opposite in the vertical direction, move closer to each other, causing the upper electrode assembly to descend while the lower electrode assembly rises. However, due to the effect of gravity, the upper electrode assembly often descends faster, which can easily cause it to collapse directly, resulting in wrinkling. When the tab is located in the upper portion, the tab may also fold due to the collapse of the upper electrode assembly. This may pose a risk of lithium plating during the subsequent charge and discharge process, affecting the reliability of the battery cell and, consequently, the battery.

[0091] Based on the above considerations, and to reduce the risk of collapse and wrinkling of the upper portion of the electrode assembly or folding of the tab during stretching, which could lead to poor reliability of the battery cell and battery, an embodiment of the present application provides a winding needle, comprising a winding needle body, the outer circumferential surface of which is provided with a pair of first and second grooves. The pair of first grooves are spaced apart along the circumference of the winding needle body, and the second grooves are spaced apart from the first grooves along the circumference of the winding needle body. The first groove is used to accommodate a first clamping needle, and the second groove is used to accommodate a second winding needle.

[0092] 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, which is positioned by the second groove, abuts against the upper half of the electrode assembly, thereby reducing the descending speed of the upper half, and reducing the risk of the upper half collapsing due to the upper half falling too quickly due to gravity, thereby causing wrinkling. At the same time, it 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.

[0093] The battery disclosed in the embodiments of the present application can be used, but is not limited to, in electrical equipment such as vehicles, ships, or aircraft. The battery disclosed in the present application can be used to form a power supply system for the electrical equipment.

[0094] The embodiments of the present application provide an electric device that uses a battery as a power source. 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. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0095] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0096] Please refer to Figure 1, which is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can 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 can be provided at the bottom, head or tail of the vehicle 1000. The battery 300 can be used to power the vehicle 1000. For example, the battery 300 can be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, such as for the working power requirements of the vehicle 1000 during startup, navigation and operation.

[0097] The vehicle 1000 may further include a controller 1100 and a motor 1200 . 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 the vehicle 1000 during startup, navigation, and driving.

[0098] In some embodiments of the present application, the battery 300 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0099] Please refer to Figure 2, which is an exploded view of a battery 300 provided in some embodiments of the present application. The battery 300 may also include a housing 310, in which the battery cells 200 are housed. The housing 310 is used to provide a storage space for the battery cells 200, and the housing 310 may adopt a variety of structures. In some embodiments, the housing 310 may include a first sub-housing 311 and a second sub-housing 312, wherein the first sub-housing 311 and the second sub-housing 312 cover each other, and the first sub-housing 311 and the second sub-housing 312 jointly define a storage space for accommodating the battery cells 200. The second sub-box 312 can be a hollow structure with one end open, and the first sub-box 311 can be a plate-like structure. 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 can also be hollow structures with one side open, and the open side of the first sub-box 311 covers the open side of the second sub-box 312.

[0100] 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 hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 200. The multiple battery cells 200 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery 300 structure may be housed within the housing 310. Of course, the battery 300 may also be formed by first connecting multiple battery cells 200 in series, in parallel, or in a hybrid connection to form a battery 300 module, and then the multiple battery 300 modules may be connected in series, in parallel, or in a hybrid connection to form a complete battery 300 structure, and then housed within the housing 310. The battery 300 may also include other structures, for example, the battery 300 may also include a busbar component for electrically connecting the multiple battery cells 200.

[0101] 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.

[0102] Please refer to Figure 3, which is an exploded view of a battery cell 200 provided in some embodiments of the present application. As shown in Figure 3, 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.

[0103] The housing 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, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. The housing 211 can be of various shapes and sizes. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 100. The material of the housing 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0104] 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 or collided, so that the battery cell 200 can have a higher structural strength and the 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 various, 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 to isolate the electrical connection components in the housing 211 from the end cap 212 to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, or the like.

[0105] Please refer to Figure 4, which is a schematic diagram of the structure of the electrode assembly provided in some embodiments of the present application. As shown in the figure, the electrode assembly 100 is the component in the battery cell 200 where the electrochemical reaction occurs. One or more electrode assemblies 100 may be contained within 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 separator 130 is usually provided between the positive electrode sheet 110 and the negative electrode sheet 120. The separator 130 is used to separate the positive electrode sheet 110 and the negative electrode sheet 120 to reduce the risk of internal short circuits between the positive electrode sheet 110 and the negative electrode sheet 120. The portions of the positive electrode sheet 110 and the negative electrode sheet 120 containing active material constitute the main body of the electrode assembly 100, and the portions of the positive electrode sheet 110 and the negative electrode sheet 120 without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately 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.

[0106] Please refer to Figures 5 to 11. Figure 5 is a schematic diagram of the structure of a winding needle provided in some embodiments of the present application. Figure 6 is a schematic diagram of the structure of the winding needle in Figure 5 from another perspective. Figure 7 is a schematic diagram of the structure of a winding needle provided in some other embodiments of the present application. Figure 8 is a schematic diagram of the structure of the winding needle in Figure 7 from another perspective. Figure 9 is a schematic diagram of the structure of a winding needle provided in some other embodiments of the present application. Figure 10 is a schematic diagram of the structure of the winding needle in Figure 9 from another perspective. Figure 11 is a schematic diagram of the structure of a winding device provided in some embodiments of the present application. As shown in the figures, the present application provides a winding needle 1, comprising a winding needle body 2, the outer circumferential surface of which is provided with a pair of first grooves 3, the first grooves 3 being used to accommodate a first clamping needle 11, and the pair of first grooves 3 being spaced apart along the circumference of the winding needle body 2; wherein the outer circumferential surface of the winding needle body 2 is further provided with at least one second groove 4, the second groove 4 being used to accommodate a second clamping needle 12, and the second groove 4 and the first groove 3 being spaced apart along the circumference of the winding needle body 2.

[0107] 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 .

[0108] In some embodiments, the winding needle body 2 can be a rotating body, which can 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.

[0109] In some embodiments, when the winding needle 1 is wound to form the electrode assembly 100, the winding needle body 2 can be arranged in a manner such that the outer circumference of the winding needle body 2 is horizontally arranged, so that the axial direction of the winding needle body 2 is in the horizontal direction. When viewed from the axial direction of the winding needle body 2, 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.

[0110] After the electrode assembly 100 is formed by winding the outer circumference of the winding needle body 2, the pair of first clamping needles 11 are respectively inserted into the pair of first grooves 3, and the second clamping needles 12 are inserted into the second grooves 4. After the winding needle body 2 is removed from the electrode assembly 100, the pair of first clamping needles 11 are moved horizontally away from each other, abutting against the inner ring of the electrode assembly 100, and the electrode assembly 100 is stretched horizontally.

[0111] At the same time, the upper and lower halves of the electrode assembly 100, the upper half, i.e., the portion of the electrode assembly 100 located above the line connecting a pair of first clamping needles 11 in the vertical direction, and the lower half, i.e., the portion of the electrode assembly 100 located below the line connecting a 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 half of the electrode assembly 100 will be greater than the rising speed of the lower half of the electrode assembly 100. The second clamping needle 12 abuts against the upper half of the electrode assembly 100 to reduce the descending speed of the upper half.

[0112] In some embodiments, the number of the second groove 4 may be one.

[0113] In some embodiments, the number of the second grooves 4 can be multiple.

[0114] In some embodiments, the second grooves 4 and the second clamping needles 12 may be provided in a one-to-one correspondence.

[0115] 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, thereby determining 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, which is positioned by the second groove 4, abuts against 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. At the same time, it 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 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0116] Please refer to Figures 5 to 11. In some embodiments, a pair of first grooves 3 are arranged along the circumference of the winding needle body 2 at intervals of 180 degrees.

[0117] 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 the two inner ring walls of the wound electrode assembly 100, and the two inner ring walls are the two inner ring walls corresponding to the diameter of the electrode assembly 100 in the horizontal direction.

[0118] 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, a pair of first grooves 3 can be arranged on the same horizontal plane on the axial surface of the winding needle body 2.

[0119] In some embodiments, due to machining errors and other factors, the angle between the pair of first grooves 3 along the circumference of the winding needle body 2 may be set to between 170° and 180°, for example, 170°, 171°, 172°, 173°, 174°, 175°, 176°, 177°, 178°, 179°, 180°, etc. When the angle between the pair of first grooves 3 is affected by machining errors, the pair of first grooves 3 are arranged such that, with the axial direction of the winding needle body 2 as the viewing direction, the pair of grooves are arranged symmetrically with respect to the vertical diameter of the electrode assembly 100 on the axial surface of the winding needle body 2.

[0120] 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 peripheral surface of the winding needle body 2, wherein the electrode assembly 100 is formed by winding the outer peripheral 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.

[0121] 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 the following: 45°≤α≤90°.

[0122] 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 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.

[0123] In some embodiments, the angle α can be measured as follows: 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 the first groove 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.

[0124] 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 farther 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 half of the electrode assembly 100 is closer to the upper end, and the angle of deviation from the upper end of the electrode assembly 100 is smaller. The second clamping needle 12 abuts against the upper half of the electrode assembly 100, which reduces the descending speed of the upper half of the electrode assembly 100, and reduces the risk of the upper half collapsing due to rapid descent due to gravity, thereby causing wrinkling. It 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 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0125] In some embodiments, 60°≤α≤90°.

[0126] In some embodiments, the angle between the second groove 4 and one of the first grooves 3 can be α, and at this time the angle between the second groove 4 and the other first groove 3 can be 180°-α, and α satisfies 60°≤α≤90°, where α can be 60°, 65°, 70°, 75°, 80°, 85°, 90°, etc.

[0127] 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. The second clamping needle 12 abuts against the upper half of the electrode assembly 100, which reduces the descending speed of the upper half of the electrode assembly 100, reduces the risk of the upper half collapsing due to rapid descent due to gravity, and thus 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 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0128] In some embodiments, 85°≤α≤90°.

[0129] In some embodiments, the angle between the second groove 4 and one of the first grooves 3 can be α, and the angle between the second groove 4 and the other first groove 3 can be 180°-α, where α satisfies 85°≤α≤90°, where α can be 85°, 86°, 87°, 88°, 89°, 90°, etc.

[0130] In some embodiments, the number of the second groove 4 may be one, and the angle α may be 90°.

[0131] 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, which reduces the descending speed of the upper half of the electrode assembly 100, reduces the risk of the upper half collapsing due to rapid descent due to gravity, and thus 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 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0132] 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. There are multiple second grooves 4, and the multiple second grooves 4 are all disposed in the first area 5.

[0133] 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 .

[0134] 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 .

[0135] 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 100 will collapse due to rapid descent, thereby causing wrinkling of the electrode sheet or tab in the upper half. In other words, only the upper half of the electrode assembly 100 requires abutment support. The outer circumference of the winding needle body 2 is divided into a first region 5 and a second region 6 by a pair of first grooves 3. Multiple second grooves 4 are all provided in the first region 5. When in use, the pair of first grooves 3 are arranged horizontally, and the second grooves 4 in the first region 5 are arranged above the pair of first grooves 3. The second grooves 4 are used to accommodate second clamping pins 12. The second clamping pins 12 abut the upper half of the electrode assembly 100, thereby reducing the descent speed of the upper half of the electrode assembly 100 and the risk of collapse and wrinkling due to rapid descent of the upper half due to gravity. It also reduces the probability of the tab folding when the tab is located in the upper half, 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. 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.

[0136] 5 to 11 , in some embodiments, a pair of first grooves 3 are symmetrically arranged relative to a first plane 7 , the central axis of the winding needle body 2 is located on the first plane 7 , and a plurality of second grooves 4 are symmetrically arranged relative to the first plane 7 .

[0137] Please refer to Figures 9 and 10. In some embodiments, the number of second grooves 4 can be an even number. The outer circumference of the winding needle body 2 is arranged horizontally, so that the axial direction of the winding needle body 2 is in the horizontal direction. When viewed from the axial direction of the winding needle body 2, the pair of first grooves 3 are located horizontally and symmetrically relative to the first plane 7. The even number of second grooves 4 is located above the pair of first grooves 3 and is symmetrically arranged relative to the first plane 7.

[0138] Please refer to Figures 7 and 8. In some embodiments, the number of second grooves 4 can be an odd number greater than one. The outer circumference 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 viewing direction, the 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. One second groove 4 can be arranged on the first plane 7, and the remaining even number of second grooves 4 are symmetrically arranged relative to the first plane 7.

[0139] 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 effects of the second clamping needles 12 located on both sides of the diameter of the electrode assembly 100 in the vertical direction are symmetrical, 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 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 of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0140] 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.

[0141] 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.

[0142] In some embodiments, both the first groove 3 and the second groove 4 extend through 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, with both ends of the first clamping needle 11 extending out of the first groove 3, or one end of the first clamping needle 11 extending out of the first groove 3 and the other end accommodated in the first groove 3; the second clamping needle 12 can be accommodated in the second groove 4, with both ends of the second clamping needle 12 extending out of the second groove 4, or one end of the second clamping needle 12 extending out of the second groove 4 and the other end accommodated in the second groove 4.

[0143] In some embodiments, the first groove 3 and the second groove 4 may not penetrate the winding needle body 2 in the axial direction. 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.

[0144] 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 pass through 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.

[0145] 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 disposed on the outer circumference of the first needle winding portion 8, and the other first groove 3 is disposed on the outer circumference of the second needle winding portion 9.

[0146] 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 achieving fine-tuning of a pair of first grooves 3 during setting, and accommodating the first clamping needle 11 by the first groove 3, thereby improving the accuracy of the installation position of the first clamping needle 11, 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.

[0147] Please refer to Figures 11 to 18. Figure 12 is a structural schematic diagram of the winding device in Figure 11 from another perspective, Figures 13 to 17 are process schematic diagrams of the winding method of the present application, Figure 18 is a structural schematic diagram of the first driving member and the second driving member of the winding device in Figure 11, and Figure 19 is a flow chart of the winding method of some embodiments of the present application. As shown in the figure, in the second aspect, the present application also 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, the pair of first clamping needles 11 being 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 needles 12 being 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.

[0148] Please refer to Figures 5 and 6. In some embodiments, the winding needle 1 includes a winding needle body 2. A pair of first grooves 3 can be provided on the outer circumference of the winding needle body 2 at 180° intervals along the circumference of the winding needle body 2, and a second groove 4 can also be provided on the outer circumference. Referring to Figure 13, the electrode assembly 100 is wound and formed on the outer circumference of the winding needle body 2. Referring to Figure 14, a pair of first clamping pins 11 are respectively accommodated in the pair of first grooves 3, and a second clamping pin 12 is accommodated in the second groove 4. The winding needle 1 is then removed from the electrode assembly 100. When viewed from the axial direction of the winding needle body 2, 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 portion corresponding to the inner diameter of the electrode assembly 100 in the horizontal direction to stretch the electrode assembly 100 in the horizontal direction. The second clamping needles 12 abut against the inner circle portion corresponding to the inner diameter of the electrode assembly 100 in the vertical direction to support the upper half of the electrode assembly 100 to reduce the descending speed of the upper half during the stretching process.

[0149] 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. The winding needle 1 takes out the electrode assembly 100 after winding it into shape, 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 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 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 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 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.

[0150] 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.

[0151] 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 can be an arc surface that protrudes away from the central axis of the winding needle body 2 .

[0152] 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 smoother, reduce the risk of damaging the electrode assembly 100, and thus improve the reliability of the battery 300.

[0153] Referring 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 .

[0154] In some embodiments, the heating element 14 may be in direct contact with the second clamping needle 12 to achieve heat conduction.

[0155] 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.

[0156] 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 heating of the second clamping needle 12 causes the adhesive of the diaphragm 130 in the upper half to melt, thereby making the bonding with 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.

[0157] In some embodiments, the heating element 14 is a resistive element.

[0158] 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 a heating effect, thereby improving the convenience of heating.

[0159] Please refer to Figure 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 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, wherein the first direction X and the second direction Y intersect.

[0160] In some embodiments, the first driving member 15 may include two driving arms, which are respectively connected to a pair of first clamping pins 11 and drive the pair of first clamping pins 11 away from each other along the first direction X, and the second driving member 16 is connected to the second clamping pin 12 to drive the second clamping pin 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 pins 11 away from each other in the horizontal direction, and the second driving member 16 drives the second clamping pin 12 to move downward in the vertical direction until the pair of first clamping pins 11 and the second clamping pin 12 are located in the same horizontal direction.

[0161] As shown in the figure, the first direction X can be represented by X, and the second direction Y can be represented by Y.

[0162] The technical solution of the embodiment of the present application is to provide a first driving member 15 connected to the first clamping pin 11 so as to drive the pair of first clamping pins 11 away from each other in the first direction X, and to provide a second driving member 16 to drive the second clamping pin 12 downward in the second direction Y, so that the two first clamping pins 11 move away from each other in the first direction X and abut against two inner walls of the electrode assembly 100 that are opposite in the first direction X, thereby stretching the electrode assembly 100 in the first direction X. This causes the second clamping pin 12 to move downward in the second direction Y and abut against the upper half of the electrode assembly 100 during the movement, thereby reducing the descent speed of the upper half and reducing the risk of the upper half collapsing due to excessive descent due to gravity, thereby causing wrinkling. It also reduces the probability of the tab folding when the tab 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. In addition, the mechanized drive facilitates the control of the speed of the first clamping pin 11 and the second clamping pin 12, which also improves the convenience of operation.

[0163] 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.

[0164] According to the technical solution of the embodiment of the present application, the winding of the electrode assembly 100 is completed by the winding device 10 , and then the battery 300 or the battery cell 200 is manufactured by the battery 300 manufacturing equipment. 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 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 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 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 of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0165] Please refer to Figures 5 to 19. Figure 19 is a 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 Figure 13, S200 the winding needle 1 winds the electrode sheet and the diaphragm 130 to form the electrode assembly 100. Please refer to Figure 14, S300 insert a pair of first clamping needles 11 into a pair of first grooves 3, and insert the second clamping needle 12 into the second groove 4. Please refer to Figure 15, S400 remove the winding needle 1 from the electrode assembly 100. Please refer to Figures 16 to 17, S500 move the pair of first clamping needles 11 away from each other to stretch the electrode assembly 100. S600 supports the upper half of the electrode assembly 100 by the second clamping needle 12 during the process of stretching the electrode assembly 100.

[0166] The technical solution of the embodiment of the present application is to wind the positive and negative electrode sheets and the separator 130 into an 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, the 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 stretching 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, and reduces the risk of the upper half collapsing due to the rapid descent of gravity, thereby causing wrinkling. At the same time, it 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 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0167] 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.

[0168] 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 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 falling 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 plating of the electrode assembly 100, improving the reliability of the battery cell 200, and thus improving the reliability of the battery 300.

[0169] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described 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 encompasses all technical solutions 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 any one of claims 1 to 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 any one of claims 3 to 4, characterized in that: 85°≤α≤90°。 6. The winding needle according to any one of claims 1 to 5, 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 any one of claims 1 to 6, 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 any one of claims 1 to 7, 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 any one of claims 1 to 8, 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 any one of claims 10 to 11, 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 any one of claims 10 to 13, 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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