Winding equipment and winding method

Abstract

The invention provides winding equipment and a winding method, and belongs to the technical field of batteries. The winding equipment comprises a feeding mechanism and a winding needle, and the feeding mechanism is used for conveying a pole piece and a diaphragm; the winding needle is used for winding a pole piece and a diaphragm conveyed by a feeding mechanism to form an electrode assembly, and the relation between the diameter r of the winding needle and the diameter R of the wound electrode assembly meets # imgabs0 #

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular to a winding device and a winding method. Background Art

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

[0003] During the production of battery cells, it is necessary to wind the electrode sheets and the separator to form the electrode assembly of the battery cell. How to improve the reliability of the battery cell is an important research direction in battery production. Summary of the Invention

[0004] The present application aims to at least solve one of the technical problems existing in the background art. For this reason, an object of the present application is to provide a winding device and a winding method, which can reduce the probability of the central hole collapse of the electrode assembly and improve the reliability of the battery cell.

[0005] An embodiment of the first aspect of the present application provides a winding device, including a feeding mechanism and a winding needle. The feeding mechanism is used to convey the electrode sheet and the separator; the winding needle is used to wind the electrode sheet and the separator conveyed by the feeding mechanism to form an electrode assembly, wherein the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies:

[0006] In the technical solution of the embodiment of the present application, the winding needle winds the electrode sheet and the separator conveyed by the feeding mechanism to form an electrode assembly, and the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: The diameter r of the winding needle is much smaller than the diameter R of the electrode assembly after winding, which can reduce the probability of the central hole collapse of the electrode assembly after winding, thereby improving the reliability of the electrode assembly.

[0007] In some embodiments, the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: The relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: It can further reduce the probability of the central hole collapse of the electrode assembly after winding, thereby further improving the reliability of the electrode assembly.

[0008] In some embodiments, the feeding mechanism includes an adjusting mechanism for clamping the electrode sheet and the separator and driving the electrode sheet and the separator to move so as to adjust the tensions of the electrode sheet and the separator. By clamping the electrode sheet and the separator with the adjusting mechanism and driving the electrode sheet and the separator to move so as to adjust the tensions of the electrode sheet and the separator, the tensions of the separator and the electrode sheet exerted on the winding needle during the winding of the electrode assembly can be reduced, the probability of deformation of the winding needle can be decreased, and thus the service life of the winding needle can be prolonged.

[0009] In some embodiments, the adjusting mechanism may include a first roller and a second roller which are oppositely arranged, and the electrode sheet and the separator pass between the first roller and the second roller; the first roller and the second roller are configured to clamp the electrode sheet and the separator and drive the electrode sheet and the separator to move so as to adjust the tensions of the electrode sheet and the separator. By the oppositely arranged first roller and second roller included in the adjusting mechanism, the conveyance of the electrode sheet and the separator can be guided, thereby improving the smoothness of the electrode sheet and the separator during conveyance.

[0010] In some embodiments, during the winding acceleration stage of winding the electrode sheet and the separator, the adjusting mechanism drives the electrode sheet and the separator to move so that the moving speed of the electrode sheet and the separator is greater than or equal to the winding speed of the winding needle winding the electrode sheet and the separator, so as to adjust the tensions of the electrode sheet and the separator. By driving the electrode sheet and the separator to move during the winding acceleration stage of winding the electrode sheet and the separator so that the moving speed of the electrode sheet and the separator is greater than or equal to the winding speed of the winding needle winding the electrode sheet and the separator, the tensions of the separator and the electrode sheet exerted on the winding needle during the winding of the electrode assembly can be reduced, the probability of deformation of the winding needle can be decreased, and thus the service life of the winding needle can be prolonged.

[0011] In some embodiments, the winding needle is of an integrally formed structure. The integrally formed structure can reduce the diameter of the winding needle, further reduce the diameter of the central hole of the wound electrode assembly, thereby further reducing the probability of collapse of the central hole of the wound electrode assembly, and further improving the reliability of the electrode assembly.

[0012] In some embodiments, the winding device further includes a winding needle auxiliary needle disposed on one side of the winding needle. The winding needle auxiliary needle and the winding needle clamp the starting ends of the electrode sheet and the separator. By arranging the winding needle auxiliary needle on one side of the winding needle, and the winding needle auxiliary needle and the winding needle clamping the starting ends of the electrode sheet and the separator, it is convenient for the winding device to wind the electrode sheet and the separator, and the winding efficiency of the winding device for the electrode assembly is improved.

[0013] In some embodiments, the winding device further includes an auxiliary mechanism. The auxiliary mechanism is disposed on one side of the winding needle and abuts against the outer periphery of the electrode assembly. The rotation direction of the auxiliary mechanism is opposite to the winding direction of the winding needle to adjust the tension of the pole piece and the diaphragm. By abutting the auxiliary mechanism against the outer periphery of the electrode assembly and setting the rotation direction of the auxiliary mechanism opposite to the winding direction of the winding needle, the influence of the tension of the pole piece and the diaphragm on the electrode assembly and the winding needle can be adjusted, thereby improving the qualification rate of the electrode assembly and extending the service life of the winding needle.

[0014] In some embodiments, the auxiliary mechanism is disposed corresponding to the position where the pole piece and the diaphragm are wound into the winding needle. Setting the auxiliary mechanism at the position where the pole piece and the diaphragm are wound into the winding needle can improve the efficiency and probability of adjusting the tension of the pole piece and the diaphragm.

[0015] In some embodiments, the winding device further includes a cutter for cutting the pole piece and the diaphragm. The cutter is disposed on the side of the feeding mechanism away from the winding needle. The cutter is disposed on the side of the feeding mechanism away from the winding needle, which can improve the reliability of the winding device and is beneficial to improving the yield rate of the electrode assembly formed by winding.

[0016] An embodiment of the second aspect of the present application provides a winding method. The winding method includes: conveying a pole piece and a diaphragm to a winding needle; the winding needle winds the pole piece and the diaphragm along a preset direction to form an electrode assembly, wherein the relationship between the diameter r of the winding needle for winding the electrode assembly and the diameter R of the electrode assembly after winding satisfies:

[0017] In the technical solution of the embodiment of the present application, the winding needle winds the conveyed pole piece and diaphragm to form an electrode assembly. The relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: The diameter r of the winding needle is much smaller than the diameter R of the electrode assembly after winding, which can reduce the probability of the central hole collapse of the electrode assembly after winding, thereby improving the reliability of the electrode assembly.

[0018] In some embodiments, the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: The relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: It can further reduce the probability of the central hole collapse of the electrode assembly after winding, thereby further improving the reliability of the electrode assembly.

[0019] In some embodiments, the winding method may further include: during the winding acceleration stage of winding the electrode tab and the separator, controlling the moving speed of the electrode tab and the separator to be greater than or equal to the winding speed of the winding needle winding the electrode tab and the separator, so as to adjust the tension of the electrode tab and the separator. By controlling the moving speed of the electrode tab and the separator during the winding acceleration stage of winding the electrode tab and the separator, such that the moving speed of the electrode tab and the separator is greater than or equal to the winding speed of the winding needle winding the electrode tab and the separator, the tension of the separator and the tension of the electrode tab received by the winding needle during the process of winding the electrode assembly can be reduced, the probability of deformation of the winding needle can be reduced, and thus the service life of the winding needle can be prolonged.

[0020] In some embodiments, the winding method may further include: controlling the rotation direction of the auxiliary mechanism to be opposite to the preset direction, so as to adjust the tension of the electrode tab and the separator. By making the rotation direction of the auxiliary mechanism opposite to the winding direction of the winding needle, the influence of the tension of the electrode tab and the separator on the electrode assembly and the winding needle can be adjusted, thereby improving the qualified rate of the electrode assembly and prolonging the service life of the winding needle.

[0021] An embodiment of the third aspect of the present application provides a battery cell, which includes an electrode assembly wound by the winding device in the above embodiment.

[0022] An embodiment of the fourth aspect of the present application provides a battery, which includes the battery cell in the above embodiment.

[0023] An embodiment of the fifth aspect of the present application provides an electrical device, which includes the battery in the above embodiment, and the battery is used to provide electrical energy.

[0024] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In the drawings, unless otherwise specified, the same reference numerals throughout the several views denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in accordance with the present application and should not be regarded as limiting the scope of the present application.

[0026] Figure 1 is a schematic structural diagram of a winding device according to some embodiments of the present application;

[0027] Figure 2 is a schematic diagram of the deformation amount of the winding needle according to some embodiments of the present application Figure 1 ;

[0028] Figure 3 is a schematic diagram of the deformation amount of the winding needle according to some embodiments of the present applicationFigure 2 ;

[0029] Figure 4 Schematic diagram of the deformation amount of the winding needle in some embodiments of the present application Figure 3 ;

[0030] Figure 5 Schematic diagram of the tension on the winding needle in some embodiments of the present application;

[0031] Figure 6 Schematic diagram of the structure of the winding needle in some embodiments of the present application;

[0032] Figure 7 Flow chart of the winding method in some embodiments of the present application.

[0033] Description of reference numerals:

[0034] 100, winding device; 110, feeding mechanism; 120, winding needle; 130, electrode tab; 140, separator; 150, electrode assembly; 160, adjusting mechanism; 161, first roller; 162, second roller; 121, auxiliary winding needle; 170, auxiliary mechanism; 180, cutter. Detailed description of the specific implementation

[0035] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0037] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality" means more than two unless otherwise specifically defined.

[0038] Reference to "embodiment" in this text means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0039] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this text generally represents an "or" relationship between the associated objects before and after.

[0040] In the description of the embodiments of this application, the term "plural" means two or more (including two). Similarly, "multiple groups" means two or more groups (including two groups), and "multiple pieces" means two or more pieces (including two pieces).

[0041] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of this application.

[0042] In the description of the embodiments of this application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0043] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydraulic, thermal, wind and solar power stations, but also widely used in electric transportation such as electric bicycles, electric motorcycles, electric vehicles, as well as in multiple fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also continuously increasing.

[0044] As an energy storage system, the cylindrical lithium-ion battery has the characteristics of mature technology, high production efficiency, and strong reliability, and has broad application prospects in the fields of civil, aviation, aerospace, military communication, and combat. In recent years, with the continuous upgrading of military and civilian energy storage systems, higher requirements have been put forward for the cycle life of lithium-ion batteries.

[0045] For cylindrical lithium-ion batteries, winding is an essential and particularly important process in the production and manufacturing of electrode assemblies. The specific method is to fix the laser-cut electrode sheets and separators on the winding needle, and rotate with the winding needle to wind the separator, positive electrode sheet, separator, and negative electrode sheet into an electrode assembly; then, processes such as shell insertion, welding, and formation are carried out to form a cylindrical lithium-ion battery.

[0046] During the charging process of the cylindrical lithium-ion battery, the expansion of the negative electrode material will drive the expansion of the electrode assembly, and the outside of the electrode assembly is the battery steel shell, with limited expansion. When the outward expansion of the electrode assembly is blocked, it will expand towards the central hole. And the continuous charging process exacerbates this process, continuously expanding towards the central hole, causing the electrode assembly to collapse towards the central hole. After the collapse of the electrode assembly, along with the expansion and contraction process during charging and non-charging states, it will increase the risk of the positive electrode cut surface piercing the separator, resulting in an increase in self-discharge of the electrode assembly and a low voltage phenomenon. In severe cases, it will cause a short circuit, fire, and explosion of the electrode assembly, seriously affecting the use safety of the cylindrical lithium-ion battery.

[0047] Based on the above considerations, in order to solve the problem that the central position of the electrode assembly is prone to collapse. This application proposes a winding device that winds the electrode sheets and separators conveyed by the winding needle feeding mechanism to form an electrode assembly. The relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: The diameter r of the winding needle is much smaller than the diameter R of the electrode assembly after winding, which can reduce the probability of the central hole collapse of the electrode assembly after winding, thereby improving the reliability of the electrode assembly.

[0048] The winding device disclosed in the embodiments of the present application can be used to wind and form an electrode assembly, and the formed electrode assembly can be used to manufacture a battery, and such a battery can be applicable to various electrical devices. The electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecrafts, electric toys, and power tools, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc.; the spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc.; the electric toys include stationary or mobile electric toys, for example, game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; the power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose special restrictions on the above-mentioned electrical devices.

[0049] According to some embodiments of the present application, the present application provides a winding device 100. Figure 1 FIG. is a schematic structural diagram of a winding device 100 provided for some embodiments of the present application. Refer to Figure 1 , the winding device 100 includes a feeding mechanism 110 and a winding needle 120. The feeding mechanism 110 is used to convey the electrode sheet 130 and the separator 140; the winding needle 120 is used to wind the electrode sheet 130 and the separator 140 conveyed by the feeding mechanism 110 to form an electrode assembly 150, wherein the relationship between the diameter r of the winding needle 120 and the diameter R of the electrode assembly 150 after winding is satisfied:

[0050] In the embodiments of the present application, the electrode sheet 130 may include a positive electrode sheet and a negative electrode sheet, and the separator 140 may include a first separator and a second separator. The first separator is located between the positive electrode sheet and the negative electrode sheet and is used to isolate the positive electrode sheet and the negative electrode sheet. The first separator and the second separator are respectively located on both sides of the negative electrode sheet. During the process of winding the electrode sheet 130 and the separator 140 by the winding device 100 to form the electrode assembly 150, the second separator can isolate the positive electrode sheet and the negative electrode sheet. The winding device 100 winds the positive electrode sheet, the negative electrode sheet, the first separator, and the second separator to form the electrode assembly 150.

[0051] In the embodiments of the present application, the feeding mechanism 110 can be used to place the coils of the electrode sheets 130 and the separator 140, and convey the electrode sheets 130 and the separator 140 according to requirements. During the process of conveying the electrode sheets 130 and the separator 140, the position of the feeding mechanism 110 can be kept unchanged, so that the feeding mechanism 110 guides the moving directions and paths of the electrode sheets 130 and the separator 140. The feeding mechanism 110 can be a driving roller. When it is necessary to release the electrode sheets 130 and the separator 140, the feeding mechanism 110 can rotate actively driven by a motor to convey the electrode sheets 130 and the separator 140; the feeding mechanism 110 can also be a driven roller. When it is necessary to release the electrode sheets 130 and the separator 140, the feeding mechanism 110 can rotate driven by the electrode sheet 130.

[0052] In the embodiments of the present application, the winding device 100 can include four feeding mechanisms 110. Among them, two feeding mechanisms 110 can be respectively used to convey the positive electrode sheet and the negative electrode sheet, and two feeding mechanisms 110 can be respectively used to convey the first separator and the second separator.

[0053] In the embodiments of the present application, the winding needle 120 can be composed of two semi-circular needles with semi-circular cross-sections. During the winding process of the electrode assembly 150, the two semi-circular needles clamp the first separator and the second separator to form a quasi-cylindrical structure. Subsequently, the winding needle 120 rotates, and the negative electrode sheet and the positive electrode sheet are sequentially inserted into the rotating separator 140 for winding. After the diameter of the electrode assembly 150 reaches the dimensional requirements, the winding needle 120 is withdrawn to complete the fabrication of the electrode assembly 150. The winding needle 120 can also be an integral structure. During the winding process of the electrode assembly 150, the winding needle 120 and the auxiliary winding needle 120 can clamp the first separator and the second separator to form a quasi-cylindrical structure. Subsequently, the winding needle 120 rotates, and the negative electrode sheet and the positive electrode sheet are sequentially inserted into the rotating separator 140 for winding. After the diameter of the electrode assembly 150 reaches the dimensional requirements, the winding needle 120 is withdrawn to complete the fabrication of the electrode assembly 150.

[0054] In one example, experiments were conducted on the electrode assembly 150 with the central hole radii of 5.5 millimeters (mm), 5 mm, and 4 mm respectively to determine the expansion rate of the electrode tab 130 when the central hole of the electrode assembly 150 collapsed. The experimental results obtained were as follows: When the expansion rate of the electrode tab 130 of the electrode assembly 150 reached 9.8%, the central hole of the electrode assembly 150 with a central hole radius of 5.5 mm began to collapse; when the expansion rate of the electrode tab 130 of the electrode assembly 150 reached 11%, the central hole of the electrode assembly 150 with a central hole radius of 5 mm began to collapse; when the expansion rate of the electrode tab 130 of the electrode assembly 150 reached 14.3%, the central hole of the electrode assembly 150 with a central hole radius of 4 mm began to collapse. The experimental results show that the smaller the central hole radius of the electrode assembly 150, the larger the expansion percentage of the electrode tab 130 at which it begins to collapse. That is to say, the smaller the diameter of the winding pin 120, the better the internal support force of the central hole of the wound electrode assembly 150.

[0055] In the related art, the diameter R of the wound electrode assembly 150 is less than or equal to 10 times the diameter r of the winding pin 120. In the embodiments of the present application, the relationship between the diameter r of the winding pin 120 and the diameter R of the wound electrode assembly 150 satisfies: That is to say, the diameter R of the wound electrode assembly 150 is at least more than 10 times the diameter r of the winding pin 120. The smaller the diameter of the winding pin 120, the smaller the radius of the internal central hole of the wound electrode assembly 150. The smaller the radius of the internal central hole of the electrode assembly 150, the greater the support strength of the internal central hole. During the subsequent cyclic expansion of the electrode assembly 150, the probability of the internal central hole of the electrode assembly 150 collapsing due to cyclic expansion can be reduced.

[0056] In the embodiments of the present application, the winding pin 120 winds the electrode tab 130 and the separator 140 conveyed by the feeding mechanism 110 to form the electrode assembly 150. The relationship between the diameter r of the winding pin 120 and the diameter R of the wound electrode assembly 150 satisfies: The diameter r of the winding pin 120 is much smaller than the diameter R of the wound electrode assembly 150, which can reduce the probability of the central hole of the wound electrode assembly 150 collapsing, thereby improving the reliability of the electrode assembly 150.

[0057] According to some embodiments, the relationship between the diameter r of the winding pin 120 and the diameter R of the wound electrode assembly 150 satisfies:

[0058] In the embodiments of the present application, if the diameter r of the winding pin 120 is too small relative to the diameter R of the electrode assembly 150 after winding, due to the too small diameter r of the winding pin 120, the winding pin 120 is more likely to deform during the winding process, which will reduce the service life of the winding pin 120. In order to reduce the probability of the central hole of the electrode assembly 150 collapsing while reducing the probability of the winding pin 120 deforming, so as to improve the service life of the winding pin 120, the diameter r of the winding pin 120 should not be too small relative to the diameter R of the electrode assembly 150 after winding. The diameter R of the electrode assembly 150 can be less than or equal to 15 times the diameter r of the winding pin 120.

[0059] In the embodiments of the present application, the relationship between the diameter r of the winding pin 120 and the diameter R of the electrode assembly 150 after winding satisfies: The probability of the central hole of the electrode assembly 150 collapsing after winding can be further reduced, thereby further improving the reliability of the electrode assembly 150.

[0060] According to some embodiments, the feeding mechanism 110 includes an adjusting mechanism 160, and the adjusting mechanism 160 is used to clamp the electrode sheet 130 and the separator 140 and drive the electrode sheet 130 and the separator 140 to move, so as to adjust the tension of the electrode sheet 130 and the separator 140.

[0061] During the winding process of the electrode assembly 150, since the separator 140 is mostly a coated ceramic, aramid, and coated separator 140, this type of separator 140 will be tightly adsorbed on the winding pin 120 due to electrostatic action during the winding process, which will cause misalignment due to spiral twisting during the winding process, resulting in a large tension on the winding pin 120. The winding pin 120 will produce deflection deformation, which will affect the service life of the winding pin 120.

[0062] In one example, experiments were conducted on the deflection deformation of the winding pin 120 when the diameter r of the winding pin 120 was 5.5 mm and the tensions on the winding pin 120 were 10 Newtons (N), 20 N, and 27 N. Figure 2 Schematic diagram of the deformation amount of the winding pin 120 in some embodiments of the present application Figure 1 , referring to Figure 2 , under the tensions of 10 N, 20 N, and 27 N, the maximum deformations of the winding pin 120 were 0.246 mm, 0.19 mm, and 0.112 mm respectively. After the tension was reduced from 27 N to 10 N, the maximum deflection deformation amount decreased by 54.47%.

[0063] In another example, experiments were conducted on the deflection deformation of the winding pin 120 when the diameter r of the winding pin 120 was 5.0 mm and the tensions on the winding pin 120 were 10 N, 20 N, and 27 N. Figure 3 Schematic diagram of the deformation amount of the winding pin 120 in some embodiments of the present application Figure 2 , referring toFigure 3 Under the action of tensions of 10 N, 20 N, and 27 N, the maximum deformations of the winding needle 120 are 0.301 mm, 0.23 mm, and 0.129 mm respectively. After the tension decreases from 27 N to 10 N, the maximum deflection deformation decreases by 57.14%.

[0064] In yet another example, experiments on the deflection deformation of the winding needle 120 are conducted when the diameter r of the winding needle 120 is 5.5 mm and 5 mm respectively, and the tension applied to the winding needle 120 is 10 N. Figure 4 Schematic diagram of the deformation amount of the winding needle 120 in some embodiments of the present application Figure 3 , referring to Figure 4 , under the action of a tension of 10 N, the maximum deflection deformation amount of the winding needle 120 with a diameter of 5.5 mm is 0.112 mm, and the maximum deflection deformation amount of the winding needle 120 with a diameter of 5.0 mm is 0.129 mm.

[0065] As can be seen from the above description, the smaller the tension applied to the winding needle 120, the smaller the deflection deformation amount of the winding needle 120.

[0066] In the embodiments of the present application, Figure 5 Schematic diagram of the tension applied to the winding needle 120 in some embodiments of the present application. As Figure 5 shown, during the winding process of the electrode assembly 150, the tension applied to the winding needle 120 includes the tension of the electrode sheet 130 and the tension of the separator 140. Adjusting the tension applied to the winding needle 120 may include simultaneously adjusting the tension of the electrode sheet 130 and the tension of the separator 140. The feeding mechanism 110 may include an adjusting mechanism 160. The adjusting mechanism 160 can clamp the electrode sheet 130 and the separator 140 and drive the electrode sheet 130 and the separator 140 to move. The direction in which the adjusting mechanism 160 drives the electrode sheet 130 and the separator 140 to move may be the same as the direction in which the winding needle 120 winds the electrode sheet 130 and the separator 140. The speed at which the adjusting mechanism 160 drives the electrode sheet 130 and the separator 140 to move may be greater than or equal to the speed at which the winding needle 120 winds the electrode sheet 130 and the separator 140, so as to reduce the tension of the electrode sheet 130 and the tension of the separator 140 applied to the winding needle 120.

[0067] In the embodiments of the present application, by clamping the electrode sheet 130 and the separator 140 with the adjusting mechanism 160 and driving the electrode sheet 130 and the separator 140 to move to adjust the tension of the electrode sheet 130 and the separator 140, the tension of the separator 140 and the tension of the electrode sheet 130 applied to the winding needle 120 during the winding process of the electrode assembly 150 can be reduced, and the probability of deformation of the winding needle 120 can be reduced, thereby improving the service life of the winding needle 120.

[0068] According to some embodiments, as Figure 1As shown, the adjusting mechanism 160 may include a first roller 161 and a second roller 162 which are oppositely arranged, and the electrode sheet 130 and the separator 140 pass between the first roller 161 and the second roller 162; the first roller 161 and the second roller 162 are used to clamp the electrode sheet 130 and the separator 140 and drive the electrode sheet 130 and the separator 140 to move, so as to adjust the tension of the electrode sheet 130 and the separator 140.

[0069] In some examples, the relative positions of the first roller 161 and the second roller 162 may be fixed. The pressure of the first roller 161 and the second roller 162 on the electrode sheet 130 and the separator 140 is small and will not affect the normal movement of the electrode sheet 130 and the separator 140. In other examples, the relative positions of the first roller 161 and the second roller 162 may also be adjustable. For example, the first roller 161 and the second roller 162 can move away from or close to each other to loosen or clamp the electrode sheet 130 and the separator 140.

[0070] In some examples, the roller surfaces of the first roller 161 and the second roller 162 may be elastic, so as to reduce the risk of the electrode sheet 130 and the separator 140 being damaged by pressure.

[0071] Exemplarily, the axial directions of the first roller 161 and the second roller 162 are parallel to the width direction of the electrode sheet 130 and the separator 140.

[0072] In the embodiment of the present application, when adjusting the tension of the electrode sheet 130, the first roller 161 and the second roller 162 can clamp the electrode sheet 130 and drive the electrode sheet 130 to move. During the movement of the electrode sheet 130, the first roller 161 and the second roller 162 press the electrode sheet 130 from both sides. Under the action of the pressure, the frictional force between the electrode sheet 130 and the first roller 161 can reduce the relative slip between the electrode sheet 130 and the first roller 161, and the frictional force between the electrode sheet 130 and the second roller 162 can reduce the relative slip between the electrode sheet 130 and the second roller 162, so that the first roller 161 and the second roller 162 drive the electrode sheet 130 to move. The first roller 161 and the second roller 162 adjust the tension of the electrode sheet 130 by adjusting the speed of driving the electrode sheet 130 to move. Exemplarily, if the speed of the first roller 161 and the second roller 162 driving the electrode sheet 130 to move is greater than or equal to the winding speed of the electrode sheet 130 by the winding needle 120, the tension of the electrode sheet 130 can be reduced.

[0073] In the embodiment of the present application, the first roller 161 and the second roller 162 which are oppositely arranged included in the adjusting mechanism 160 can guide the conveyance of the electrode sheet 130 and the separator 140, thereby improving the smoothness of the electrode sheet 130 and the separator 140 during conveyance.

[0074] According to some embodiments, during the winding acceleration stage of the wound electrode tab 130 and the separator 140, the adjusting mechanism 160 drives the electrode tab 130 and the separator 140 to move, so that the moving speed of the electrode tab 130 and the separator 140 is greater than or equal to the winding speed of the winding needle 120 for winding the electrode tab 130 and the separator 140, thereby adjusting the tension of the electrode tab 130 and the separator 140.

[0075] During the process of the winding needle 120 winding the electrode tab 130 and the separator 140 to form the electrode assembly 150, it usually goes through a preparation stage (including preparation work such as changing workstations and threading the needle), a pre-winding and feeding stage (starting to wind, at this time the rotation speed of the winding needle 120 is slow), a starting winding acceleration stage (the rotation speed of the winding needle 120 rapidly increases), a constant-speed winding stage (the rotation speed of the winding needle 120 is relatively fast and remains unchanged), a deceleration winding stage (the rotation speed of the winding needle 120 gradually decreases), and a finishing stage.

[0076] During the winding acceleration stage of the wound electrode tab 130 and the separator 140, the rotation speed of the winding needle 120 will rapidly increase. That is to say, the winding speed of the winding needle 120 for winding the electrode tab 130 and the separator 140 will also rapidly increase. At this time, if the moving speed of the electrode tab 130 and the separator 140 is less than the winding speed of the winding needle 120 for winding the electrode tab 130 and the separator 140, the tension of the electrode tab 130 and the separator 140 will increase, which will cause the winding needle 120 to deflect and deform, thus affecting the service life of the winding needle 120. In the embodiments of the present application, during the winding acceleration stage of the wound electrode tab 130 and the separator 140, the adjusting mechanism 160 drives the electrode tab 130 and the separator 140 to move, so that the moving speed of the electrode tab 130 and the separator 140 is greater than or equal to the winding speed of the winding needle 120 for winding the electrode tab 130 and the separator 140, and the tension of the electrode tab 130 and the separator 140 can be adjusted to reduce the tension of the electrode tab 130 and the separator 140.

[0077] In the embodiments of the present application, by driving the electrode tab 130 and the separator 140 to move through the adjusting mechanism 160 during the winding acceleration stage of the wound electrode tab 130 and the separator 140, so that the moving speed of the electrode tab 130 and the separator 140 is greater than or equal to the winding speed of the winding needle 120 for winding the electrode tab 130 and the separator 140, the tension of the separator 140 and the electrode tab 130 received by the winding needle 120 during the winding of the electrode assembly 150 can be reduced, the probability of deformation of the winding needle 120 can be reduced, and thus the service life of the winding needle 120 can be improved.

[0078] According to some embodiments, the winding needle 120 is an integrally formed structure.

[0079] In the related art, the winding needle 120 is mainly composed of two semi-circular winding needles 120 with semi-circular cross-sections. During the winding process of the electrode assembly 150, the two semi-circular winding needles 120 clamp the separator 140 to form a cylindrical-like structure. Subsequently, the winding needle 120 rotates, and the negative electrode sheet and the positive electrode sheet are sequentially inserted into the rotating separator 140 for winding. After the electrode assembly 150 reaches the dimensional requirements, the winding needle 120 is withdrawn to complete the fabrication of the electrode assembly 150. Since there will be a gap between the two semi-circular winding needles 120, the diameter of the winding needle 120 composed of the two semi-circular winding needles 120 will be larger than that of the integrally formed winding needle 120. Therefore, in the embodiments of the present application, the winding needle 120 is of an integrally formed structure.

[0080] In the embodiments of the present application, the cross-sectional shape of the winding needle 120 can be circular or elliptical, and the winding needle 120 can be a hollow structure or a solid structure.

[0081] Exemplarily, the cross-sectional shape of the winding needle 120 can be any shape such as circular or elliptical.

[0082] In the embodiments of the present application, the integrally formed structure can reduce the diameter of the winding needle 120, further reduce the diameter of the central hole of the wound electrode assembly 150, thereby further reducing the probability of the central hole of the wound electrode assembly 150 collapsing, and further improving the reliability of the electrode assembly 150.

[0083] According to some embodiments, Figure 6 is a schematic structural diagram of the winding needle for some embodiments of the present application. As Figure 5 shown, the winding device 100 further includes a winding needle auxiliary needle 121. The winding needle auxiliary needle 121 is disposed on one side of the winding needle 120 and clamps the starting ends of the electrode sheet 130 and the separator 140 together with the winding needle 120.

[0084] In the embodiments of the present application, since the winding needle 120 is of an integrally formed structure, the winding needle 120 cannot clamp the electrode sheet 130 and the separator 140 to start winding at the beginning. The winding needle auxiliary needle 121 can cooperate with the winding needle 120 to clamp the starting ends of the electrode sheet 130 and the separator 140 and start winding to form the electrode assembly 150.

[0085] In the embodiments of the present application, the cross-sectional shape of the winding needle auxiliary needle 121 corresponds to the shape of the winding needle 120. For example, when the shape of the winding needle 120 is circular, the shape of the winding needle auxiliary needle 121 is arc-shaped. The winding needle auxiliary needle 121 can be attached to the outer surface of the winding needle 120 to facilitate clamping the starting ends of the electrode sheet 130 and the separator 140. And after the winding device 100 winds the electrode sheet 130 and the separator 140 to a preset thickness, the winding needle auxiliary needle 120 can be removed.

[0086] In an embodiment of the present application, a winding needle auxiliary needle 121 is arranged on one side of the winding needle 120. The winding needle auxiliary needle 121 and the winding needle 120 clamp the starting ends of the electrode tab 130 and the separator 140, facilitating the winding device 100 to wind the electrode tab 130 and the separator 140, and improving the winding efficiency of the winding device 100 for the electrode assembly 150.

[0087] According to some embodiments, the winding device 100 further includes an auxiliary mechanism 170. The auxiliary mechanism 170 is arranged on one side of the winding needle 120. The auxiliary mechanism 170 abuts against the outer periphery of the electrode assembly 150. The rotation direction of the auxiliary mechanism 170 is opposite to the winding direction of the winding needle 120 to adjust the tension of the electrode tab 130 and the separator 140.

[0088] In an embodiment of the present application, the cross-section of the auxiliary mechanism 170 can be circular, and the axial length of the auxiliary mechanism 170 can be greater than or equal to the axial length of the winding needle 120. The setting of the axial length of the auxiliary mechanism 170 can achieve complete pressing against the electrode assembly 150, thereby improving the uniformity of the tension relief of the electrode tab 130 and the separator 140 at various positions of the electrode assembly 150. The outer diameter of the auxiliary mechanism 170 can be selected according to the diameter of the wound electrode assembly 150. For example, the outer diameter of the auxiliary mechanism 170 can be selected to be less than or equal to the diameter of the wound electrode assembly 150 to adjust the influence of the tension of the electrode tab 130 and the separator 140 on the electrode assembly 150 and the winding needle 120, improve the qualification rate of the electrode assembly 150, and extend the service life of the winding needle 120.

[0089] In an embodiment of the present application, the outer peripheral surface of the auxiliary mechanism 170 can be made of a flexible material. The flexible material can be rubber or carbon fiber, etc., which has good wear resistance and surface smoothness, and can have a certain elasticity and flexibility. The auxiliary mechanism 170 made of the flexible material can reduce the surface roughness and hardness, improve the smoothness, avoid scratching or bruising the surface of the electrode assembly 150 or causing the electrode tab 130 and the separator 140 to wrinkle, improve the protection of the electrode assembly 150, and thus improve the qualification rate of the electrode assembly 150. The outer peripheral surface of the auxiliary mechanism 170 can be an integrally formed structure with the internal structure of the auxiliary mechanism 170. For example, the auxiliary mechanism 170 is a rubber wheel, or only a rubber layer is wrapped around the outer peripheral side of the auxiliary mechanism 170, which is not limited herein.

[0090] In the embodiments of the present application, the auxiliary mechanism 170 can abut against the outer periphery of the electrode assembly 150 and rotate relative to the pole piece 130. By setting the rotation direction and abutting pressure of the auxiliary mechanism 170, it is possible to rotate in the direction opposite to the winding direction at the initial stage of winding, so as to cut off the tension of the pole piece 130 and the separator 140, reduce the pulling and pressing of the tension on the pole piece 130 and the separator 140, and thus increase the layer gap of the inner ring; at the later stage of winding, by pressing on the electrode assembly 150, the pole piece 130 or the separator 140 of the outer ring is compacted, so as to reduce the winding gap of the outer ring, improve the difference in the layer gap between the inner ring and the outer ring, and further improve the problems of the central hole collapse of the electrode assembly 150 and the lithium deposition on the outer ring, and improve the service performance of the electrode assembly 150.

[0091] In the embodiments of the present application, by abutting the auxiliary mechanism 170 against the outer periphery of the electrode assembly 150 and setting the rotation direction of the auxiliary mechanism 170 opposite to the winding direction of the winding needle 120, the influence of the tension of the pole piece 130 and the separator 140 on the electrode assembly 150 and the winding needle 120 can be adjusted, so as to improve the qualification rate of the electrode assembly 150 and extend the service life of the winding needle 120.

[0092] According to some embodiments, the auxiliary mechanism 170 is arranged corresponding to the position where the pole piece 130 and the separator 140 are wound into the winding needle 120.

[0093] In the embodiments of the present application, at the position where the pole piece 130 and the separator 140 are about to be wound into the winding needle 120, the pole piece 130 and the separator 140 at this position have a greater degree of freedom relative to the pole piece 130 and the separator 140 at other positions of the electrode assembly 150. In order to improve the tension adjustment effect of the auxiliary mechanism 170, the auxiliary mechanism 170 is arranged at this position. Through the frictional action with the pole piece 130 and the separator 140 at this position, the tension of the pole piece 130 and the separator 140 at this position can be reduced, making the improvement effect more obvious.

[0094] In the embodiments of the present application, arranging the auxiliary mechanism 170 at the position where the pole piece 130 and the separator 140 are wound into the winding needle 120 can improve the efficiency and probability of adjusting the tension of the pole piece 130 and the separator 140.

[0095] According to some embodiments, the winding device 100 further includes a cutter 180 for cutting off the pole piece 130 and the separator 140, and the cutter 180 is arranged on the side of the feeding mechanism 110 away from the winding needle 120.

[0096] In the embodiment of the present application, the cutting knife 180 is disposed on a side of the feeding mechanism 110 away from the winding needle 120. After the length of the pole piece 130 or the separator 140 reaches a preset length, the cutting knife 180 cuts off the pole piece 130 or the separator 140. After the cutting knife 180 cuts off the pole piece 130 and the separator 140, the feeding mechanism 110 can still convey the pole piece 130 and the separator 140, and convey the pole piece 130 and the separator 140 to the winding needle 120 for winding.

[0097] In the embodiment of the present application, the cutting knife 180 is disposed on a side of the feeding mechanism 110 away from the winding needle 120, which can improve the reliability of the winding device 100 and is beneficial to improving the yield rate of the electrode assembly 150 formed by winding.

[0098] Figure 7 is a flowchart of a winding method provided by some embodiments of the present application. As Figure 7 shown, the winding method includes:

[0099] Step S710: Convey the pole piece and the separator to the winding needle.

[0100] Step S720: The winding needle winds the pole piece 130 and the separator along a preset direction to form an electrode assembly. Wherein, the relationship between the diameter r of the winding needle for winding the electrode assembly and the diameter R of the electrode assembly after winding is satisfied:

[0101] In the embodiment of the present application, the pole piece may include a positive pole piece and a negative pole piece, and the separator may include a first separator and a second separator. The first separator is located between the positive pole piece and the negative pole piece and is used to isolate the positive pole piece and the negative pole piece. The first separator and the second separator are respectively located on both sides of the negative pole piece.

[0102] In the related art, the diameter R of the wound electrode assembly is less than or equal to 10 times the diameter r of the winding needle. However, in the embodiment of the present application, the relationship between the diameter r of the winding needle and the diameter R of the wound electrode assembly is satisfied: That is to say, the diameter R of the wound electrode assembly is at least more than 10 times the diameter r of the winding needle. Relatively speaking, in the present application, the diameter of the winding needle is smaller, and the radius of the central hole inside the wound electrode assembly is smaller. The smaller the radius of the central hole inside the electrode assembly, the greater the support strength of the central hole. During the later cyclic expansion of the electrode assembly, the probability of collapse of the central hole inside the electrode assembly caused by the later cyclic expansion can be reduced.

[0103] In the embodiment of the present application, the winding needle winds the conveyed pole piece and separator to form an electrode assembly. The relationship between the diameter r of the winding needle and the diameter R of the wound electrode assembly is satisfied: The diameter r of the winding needle is much smaller than the diameter R of the electrode assembly after winding, which can reduce the probability of the central hole of the electrode assembly after winding from collapsing, thereby improving the reliability of the electrode assembly.

[0104] According to some embodiments of the present application, the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies:

[0105] In the embodiments of the present application, if the diameter r of the winding needle is too small relative to the diameter R of the electrode assembly after winding, due to the too small diameter r of the winding needle, the winding needle will be more likely to deform during winding, resulting in a reduction in the service life of the winding needle. In order to reduce the probability of the winding needle deforming to improve the service life of the winding needle while reducing the probability of the central hole of the electrode assembly from collapsing, the diameter r of the winding needle should not be too small relative to the diameter R of the electrode assembly after winding, and the diameter R of the electrode assembly can be less than or equal to 15 times the diameter r of the winding needle.

[0106] In the embodiments of the present application, the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding satisfies: It is possible to further reduce the probability of the central hole of the electrode assembly after winding from collapsing, thereby further improving the reliability of the electrode assembly.

[0107] According to some embodiments of the present application, the winding method may further include: during the winding acceleration stage of winding the pole piece and the separator, controlling the moving speed of the pole piece and the separator to be greater than or equal to the winding speed of the winding needle winding the pole piece and the separator, so as to adjust the tension of the pole piece and the separator.

[0108] During the process of the winding needle winding the pole piece and the separator to form an electrode assembly, it generally goes through a preparation stage (including preparation work such as changing workstations and threading the needle), a pre-winding and feeding stage (starting to wind, at this time the rotation speed of the winding needle is slow), a starting winding acceleration stage (the rotation speed of the winding needle increases rapidly), a constant-speed winding stage (the rotation speed of the winding needle is fast and remains unchanged), a decelerating winding stage (the rotation speed of the winding needle gradually decreases), and a finishing stage.

[0109] During the winding acceleration stage of winding the pole piece and the separator, the rotation speed of the winding needle will increase rapidly, that is to say, the winding speed of the winding needle winding the pole piece and the separator will also increase rapidly. At this time, if the moving speed of the pole piece and the separator is less than the winding speed of the winding needle winding the pole piece and the separator, the tension of the pole piece and the separator will increase, causing the winding needle to deflect and deform, thus affecting the service life of the winding needle. In the embodiments of the present application, during the winding acceleration stage of winding the pole piece and the separator, controlling the moving speed of the pole piece and the separator so that the moving speed of the pole piece and the separator is greater than or equal to the winding speed of the winding needle winding the pole piece and the separator can adjust the tension of the pole piece and the separator, reducing the tension of the pole piece and the separator.

[0110] In the embodiments of the present application, during the winding acceleration stage of the wound electrode sheet and the separator, the moving speeds of the electrode sheet and the separator are controlled so that the moving speeds of the electrode sheet and the separator are greater than or equal to the winding speed of the winding needle for winding the electrode sheet and the separator, which can reduce the tensions of the separator and the electrode sheet exerted on the winding needle during the process of winding the electrode assembly, reduce the probability of deformation of the winding needle, and thus improve the service life of the winding needle.

[0111] According to some embodiments of the present application, the winding method may further include: controlling the rotation direction of the auxiliary mechanism to be opposite to the preset direction to adjust the tensions of the electrode sheet and the separator.

[0112] In the embodiments of the present application, the auxiliary mechanism can abut against the outer periphery of the electrode assembly and rotate relative to the electrode sheet. By setting the rotation direction and the abutting pressure of the auxiliary mechanism, it is possible to rotate in the direction opposite to the winding direction at the initial stage of winding, play a role in isolating the tensions of the electrode sheet and the separator, reduce the pulling and pressing of the tensions on the electrode sheet and the separator, and thus increase the layer gap of the inner circle; at the later stage of winding, by pressing on the electrode assembly, the electrode sheet or the separator of the outer circle is compacted, thereby reducing the winding gap of the outer circle, improving the difference in the layer gap between the inner circle and the outer circle, and further improving the problems of central hole collapse and outer circle lithium deposition of the electrode assembly, and improving the service performance of the electrode assembly.

[0113] In the embodiments of the present application, by making the rotation direction of the auxiliary mechanism opposite to the winding direction of the winding needle, the influence of the tensions of the electrode sheet and the separator on the electrode assembly and the winding needle can be adjusted, thereby improving the qualification rate of the electrode assembly and extending the service life of the winding needle.

[0114] The embodiments of the present application further provide a battery cell, and the battery cell includes an electrode assembly wound by the winding device in the above embodiments.

[0115] The battery cell in the embodiments of the present application may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of the present disclosure do not limit this. The battery cell can be in a cylindrical shape, a flat shape, a cuboid shape or other shapes, etc., and the embodiments of the present application also do not limit this. Generally, the battery cell is classified into a cylindrical battery cell, a square battery cell and a soft-pack battery cell according to the packaging method, and the embodiments of the present application also do not limit this.

[0116] In the embodiments of the present application, by using the electrode assembly wound by the winding device, the probability of central hole collapse of the electrode assembly can be reduced, thereby improving the reliability of the battery cell.

[0117] The embodiments of the present application further provide a battery, and the battery includes the battery cell in any implementation manner.

[0118] In the embodiments of the present application, the battery can be applied to, but not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, electric vehicles, ships, spacecraft, etc. Among them, the electric toys can include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric plane toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0119] In the embodiments of the present application, by using a winding device to wind and form an electrode assembly, the probability of the central hole of the electrode assembly collapsing can be reduced, the reliability of the battery cell can be improved, and thus the reliability of the battery can be improved.

[0120] The embodiments of the present application further provide an electrical device, which includes the battery in any implementation manner, and the battery is used to provide electrical energy.

[0121] In the embodiments of the present application, the electrical device can be, but not limited to, mobile phones, tablets, laptop computers, electric toys, electric tools, battery cars, electric vehicles, ships, spacecraft, etc. Among them, the electric toys can include stationary or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric plane toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0122] In the embodiments of the present application, by using the battery in the embodiments of the present application, the probability of the central hole of the electrode assembly collapsing can be reduced, so that the reliability of the electrical device is improved.

[0123] The technical solution of the present application will be described below through a specific embodiment. As Figures 1 to 6 shown, the winding device 100 includes a feeding mechanism 110, a winding needle 120, an auxiliary mechanism 170, and a cutting knife 180. The winding needle 120 is an integrally formed structure, and the auxiliary winding needle 121 of the winding needle is provided on one side of the winding needle 120, and clamps the starting ends of the electrode sheet 130 and the separator 140 together with the winding needle 120. The feeding mechanism 110 is used to convey the electrode sheet 130 and the separator 140; the winding needle 120 is used to wind the electrode sheet 130 and the separator 140 conveyed by the feeding mechanism 110 to form an electrode assembly 150, wherein the relationship between the diameter r of the winding needle 120 and the diameter R of the wound electrode assembly 150 satisfies:

[0124] The feeding mechanism 110 includes an adjusting mechanism 160. The adjusting mechanism 160 includes a first roller 161 and a second roller 162 which are oppositely arranged. The pole piece 130 and the separator 140 pass between the first roller 161 and the second roller 162. The first roller 161 and the second roller 162 are used to clamp the pole piece 130 and the separator 140 and drive the pole piece 130 and the separator 140 to move, so as to adjust the tension of the pole piece 130 and the separator 140. During the winding acceleration stage of winding the pole piece 130 and the separator 140, the adjusting mechanism 160 drives the pole piece 130 and the separator 140 to move, so that the moving speed of the pole piece 130 and the separator 140 is greater than or equal to the winding speed of the winding needle 120 winding the pole piece 130 and the separator 140, so as to adjust the tension of the pole piece 130 and the separator 140.

[0125] The auxiliary mechanism 170 is arranged corresponding to the position where the pole piece 130 and the separator 140 are wound into the winding needle 120. The auxiliary mechanism 170 abuts against the outer periphery of the electrode assembly 150. The rotation direction of the auxiliary mechanism 170 is opposite to the winding direction of the winding needle 120, so as to adjust the tension of the pole piece 130 and the separator 140.

[0126] The cutter 180 is used to cut off the pole piece 130 and the separator 140. The cutter 180 is arranged on the side of the feeding mechanism 110 away from the winding needle 120.

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A winding device, characterized in that, Comprising: A feeding mechanism for conveying the electrode sheet and the separator; The winding needle is used to wind the pole piece and the separator conveyed by the feeding mechanism to form an electrode assembly. Wherein, the relationship between the diameter r of the winding needle and the diameter R of the electrode assembly after winding is satisfied as follows:

2. The winding device according to claim 1, characterized in that, The relationship between the diameter r of the coiling needle and the diameter R of the electrode assembly after coiling is satisfied as follows:

3. The winding device according to claim 1 or 2, characterized in that, The feeding mechanism includes an adjusting mechanism for clamping the electrode sheet and the separator and driving the electrode sheet and the separator to move, so as to adjust the tension of the electrode sheet and the separator.

4. The winding device according to claim 3, characterized in that, The adjusting mechanism includes a first roller and a second roller arranged oppositely, and the electrode sheet and the separator pass between the first roller and the second roller; The first roller and the second roller are used for clamping the electrode sheet and the separator and driving the electrode sheet and the separator to move, so as to adjust the tension of the electrode sheet and the separator.

5. The device according to claim 3, characterized in that, During the winding acceleration stage of winding the electrode sheet and the separator, the adjusting mechanism drives the electrode sheet and the separator to move, so that the moving speed of the electrode sheet and the separator is greater than or equal to the winding speed of the winding needle winding the electrode sheet and the separator, so as to adjust the tension of the electrode sheet and the separator.

6. The winding device according to any one of claims 1 to 5, characterized in that, The winding needle is an integrally formed structure.

7. The winding device according to any one of claims 1 to 6, characterized in that, The winding device further includes a winding needle auxiliary needle, the winding needle auxiliary needle is arranged on one side of the winding needle, and the winding needle auxiliary needle and the winding needle clamp the starting ends of the electrode sheet and the separator.

8. The winding device according to any one of claims 1 to 7, characterized in that, The winding device further includes an auxiliary mechanism, the auxiliary mechanism is arranged on one side of the winding needle, the auxiliary mechanism abuts against the outer periphery of the electrode assembly, and the rotation direction of the auxiliary mechanism is opposite to the winding direction of the winding needle, so as to adjust the tension of the electrode sheet and the separator.

9. The winding device according to claim 8, wherein The auxiliary mechanism is arranged corresponding to the position where the electrode sheet and the separator are wound into the winding needle.

10. The winding device according to any one of claims 1 to 9, characterized in that, It further includes a cutter for cutting off the electrode sheet and the separator, and the cutter is arranged on the side of the feeding mechanism away from the winding needle.

11. A winding method, characterized in that, The method includes: Conveying the electrode sheet and the separator to the winding needle; The winding needle winds the electrode tab and the separator along a preset direction to form an electrode assembly, wherein the relationship between the diameter r of the winding needle for winding the electrode assembly and the diameter R of the electrode assembly after winding is satisfied as follows:

12. The method according to claim 11, wherein The relationship between the diameter r of the coiling needle and the diameter R of the electrode assembly after coiling is satisfied as follows:

13. The method according to claim 11 or 12, characterized in that, The method further includes: During the winding acceleration stage of winding the electrode sheet and the separator, controlling the moving speed of the electrode sheet and the separator to be greater than or equal to the winding speed of the winding needle winding the electrode sheet and the separator, so as to adjust the tension of the electrode sheet and the separator.

14. The method according to any one of claims 11 to 13, characterized in that, The method further includes: Controlling the rotation direction of the auxiliary mechanism to be opposite to the preset direction, so as to adjust the tension of the electrode sheet and the separator.

15. A battery cell, characterized in that, Including an electrode assembly wound by the winding device according to any one of claims 1 to 10.

16. A battery, characterized in that, Including a battery cell according to claim 15.

17. An electrical device, characterized in that, The electrical device includes the battery according to claim 16, and the battery is used to provide electrical energy.

Images