A battery cell winding mechanism, winding equipment and winding method

Abstract

This application relates to the field of lithium-ion battery technology, and discloses a cell winding mechanism, winding equipment, and winding method. The cell winding mechanism includes winding needles, a driving device, and an ejector device. The winding needles include multiple winding needle components arranged sequentially along the circumference, and each winding needle component has a through arc-shaped groove on its outer peripheral wall along the circumference. The driving device is used to drive the winding needle components to move closer or further apart. The ejector device includes multiple top plates disposed inside the winding needles and corresponding to the positions of the arc-shaped grooves. The top plates are inserted into their corresponding arc-shaped grooves, and the outer end face of the top plate is an arc shape that matches the corresponding arc-shaped groove, and can extend out of the arc-shaped groove or retract into the arc-shaped groove. This can avoid wrinkles, collapses, or interlayer misalignment of the inner layers of the core due to sagging and deformation of the inner layer material, thereby improving the performance and reliability of the cell.

Description

Technical Field

[0001] This application relates to the field of lithium-ion battery technology, and in particular to a cell winding mechanism, winding equipment and winding method. Background Technology

[0002] Lithium-ion batteries are widely used in consumer electronics, electric vehicles, and energy storage systems due to their advantages such as high energy density, long cycle life, and no memory effect. The battery cell, as the core component of a lithium-ion battery, is typically made by stacking or winding positive and negative electrode sheets and a separator between them. Among these, wound cells (or simply wound cores) are widely used because of their high production efficiency, compact structure, and ease of mass production. In the winding process, the positive and negative electrode sheets and the separator are synchronously fed to the winding station under a preset tension and tightly wound in multiple layers around a central support structure, ultimately forming a cylindrical or square wound core. This winding process is mainly completed by winding equipment.

[0003] The cell winding needle mechanism, as the core actuator in the winding equipment, is mainly used to support, position, and guide the electrode sheets and separators to form a preset contour during the winding process. The cell winding needle mechanism typically includes a retractable winding needle and a drive unit connected to it. The winding needle provides the basic winding contour and support surface for the electrode sheets and separators; the drive unit, as the power source, controls the opening and closing of the winding needle using cylinders or motors to achieve diameter changes during the winding process. A typical winding method is roughly as follows: first, the separator and electrode sheets are introduced and positioned on the winding needle in an open state; then, the winding needle rotates, driving multiple layers of material to be wound synchronously to form a core; after winding to a set number of turns, the drive unit controls the winding needle to retract, causing it to detach from the inner wall of the core; finally, the winding needle is pulled out from the center of the core (referred to as core pulling), completing one winding cycle.

[0004] However, in the actual production process of the core, after the winding is completed and the drive unit drives the winding needle to retract and complete the core pulling, the inner layer material of the core will sag and deform under its own gravity due to the loss of the mechanical support of the winding needle. This phenomenon is particularly significant in the innermost ring area of ​​the core, which causes the separator and the electrode to be unable to maintain the original tight fit. This results in irreversible wrinkles, collapses or interlayer misalignments inside the core, directly affecting the internal uniformity and interface stability of the cell, causing a decline in the overall performance of the cell, and may even lead to safety hazards. Summary of the Invention

[0005] This application provides a battery cell winding mechanism, winding equipment, and winding method, which can avoid wrinkles, collapses, or interlayer misalignment of the inner layer of the battery cell caused by sagging and deformation of the inner layer material, thereby improving the performance and reliability of the battery cell.

[0006] To achieve the above objectives, the main technical solutions adopted in this application include: In a first aspect, embodiments of this application provide a battery cell winding mechanism, comprising: A coiled needle includes multiple coiled needle components arranged sequentially along the circumference, each of the coiled needle components including an outer peripheral wall, the outer peripheral wall having a through arc-shaped groove along the circumference; A driving device is used to drive each of the coiled needles to move closer or further apart from each other; The ejector device includes multiple top plates disposed inside the winding needle and corresponding to the position of the arc-shaped groove; the top plates are inserted into the corresponding arc-shaped grooves, the outer end face of the top plates is an arc shape that matches the corresponding arc-shaped grooves, and can extend out of the arc-shaped grooves or retract into the arc-shaped grooves.

[0007] This application proposes a battery cell winding mechanism. By providing a through arc-shaped groove on the outer peripheral wall of the winding needle and arranging a retractable top plate within the arc-shaped groove, a permanent arc-shaped imprint can be formed on the inner layer material of the core by controlling the top plate to extend beyond the arc-shaped groove during or after winding. This imprint acts as a structural reinforcing rib, effectively resisting sagging deformation caused by gravity and ensuring that the inner layer material of the core is tightly adhered along the imprint. This prevents wrinkles, collapses, or interlayer misalignment of the inner layer of the core, improves the internal uniformity and interface stability of the battery cell, and thus enhances the performance and reliability of the battery cell.

[0008] Optionally, the needle coiling components are provided in pairs, having a first direction, a second direction, and a third direction that are perpendicular to each other, and the two needle coiling components are arranged opposite each other along the first direction.

[0009] In the above scheme, by setting the winding needle component as two semi-circular structures arranged opposite each other along the first direction, it is convenient to realize the rapid opening and closing of the winding needle, simplify the structural design of the driving device, and improve the core pulling efficiency and equipment reliability; at the same time, it can ensure the uniformity of the support of the winding needle to the electrode sheet and diaphragm during the winding process, and improve the roundness consistency of the core.

[0010] Optionally, the top plate includes a first arc-shaped plate and a second arc-shaped plate arranged opposite to each other along the second direction; the adjacent sides of the first arc-shaped plate and the second arc-shaped plate gradually move away from each other outward and form an included angle α, and form a trapezoidal groove inward; along the first direction from the outside to the inside, the inner diameter of the trapezoidal groove gradually increases, and the included angle between the two side walls of the trapezoidal groove is β1; The ejection device further includes an ejection drive component and a trapezoidal push block; the included angle between the two side walls of the trapezoidal push block is β2, and β2-β1=α; the trapezoidal push block is installed in the trapezoidal groove and can move along the first direction under the drive of the ejection drive component to abut or move away from the inner wall of the trapezoidal groove.

[0011] In the above scheme, by setting the top plate as a first arc-shaped plate and a second arc-shaped plate arranged opposite to each other along the second direction, and making their adjacent sides gradually move away from each other outward to form an included angle α, forming a trapezoidal groove inward with the included angle between the two side walls of the trapezoidal groove being β1, and simultaneously making the included angle β2 between the two side walls of the trapezoidal push block greater than β1, and satisfying β2-β1=α, when the ejection driving component pushes the trapezoidal push block to move along the first direction to abut against the inner wall of the trapezoidal groove, since β2>β1, the side wall of the trapezoidal push block generates an angle along the inner wall of the two side walls of the trapezoidal groove. The outward pushing force in the second direction causes the first and second arc-shaped plates to not only push outward along the first direction, but also to unfold outward synchronously, so that their tops gradually approach each other, the included angle α gradually disappears, and finally they are joined into a continuous arc surface. This structure can realize the synchronous and symmetrical pushing out of the first and second arc-shaped plates, and finally form a circumferentially continuous and uniformly deep arc-shaped imprint in the inner layer of the core, which significantly improves the forming quality of the imprint and the uniformity of the force on the inner layer of the core, and can further improve the internal uniformity and interface stability of the battery cell, thereby improving the performance and reliability of the battery cell.

[0012] Optionally, the angle range of β1 is 19°-39°, and the angle range of β2 is 20°-40°.

[0013] In the above scheme, by limiting β1 and β2 within the above angle range, it is ensured that the trapezoidal pusher can generate sufficient thrust component along the second direction to drive the top plate to extend during the movement, while avoiding the problem of self-locking or a sharp increase in friction caused by excessive angle, thus ensuring that the ejection device operates smoothly and reliably.

[0014] Optionally, the side wall of the trapezoidal push block is provided with a plurality of pulleys.

[0015] In the above scheme, by setting the pulley on the side wall of the trapezoidal push block, the sliding friction between the trapezoidal push block and the inner wall of the trapezoidal groove can be converted into rolling friction, which significantly reduces frictional resistance, makes the ejection and retraction actions smoother, reduces component wear, and improves the service life and action sensitivity of the ejection device.

[0016] Optionally, the needle winding component is provided with a connecting plate that is connected to the output end of the driving device; the connecting plate is provided with two sets of guide grooves, and the two sets of guide grooves are arranged in a one-to-one correspondence with the first arc plate and the second arc plate; The guide groove includes a first guide groove and a second guide groove; the first guide groove extends along the first direction and is located on the side of the first arc plate or the second arc plate close to the trapezoidal groove; a first connecting post is slidably connected in the first guide groove, and the first connecting post is fixedly connected to the first arc plate or the second arc plate. The second guide groove is arc-shaped and its center is located at the end of the first guide groove away from the center of the coiling needle; a second connecting post is slidably connected in the second guide groove, and the second connecting post is fixedly connected to the first arc plate or the second arc plate.

[0017] In the above scheme, by setting a composite guiding structure of the first guide groove and the second guide groove, the movement trajectory of the first arc-shaped plate and the second arc-shaped plate can be precisely constrained. Specifically, the first guide groove extends along the first direction, ensuring the movement accuracy of the first arc-shaped plate and the second arc-shaped plate along the first direction during extension and retraction; the second guide groove is arc-shaped with its center located at an end away from the center of the winding needle, ensuring the rotational movement accuracy of the first arc-shaped plate and the second arc-shaped plate as they extend outward, thereby ensuring that their outer end faces always fit well with the inner wall of the winding core, ensuring uniform and consistent imprint depth.

[0018] Optionally, each of the needle coiling components is provided with two arc-shaped grooves symmetrically arranged on both sides of the connecting plate along the third direction, and the arc-shaped grooves of all the needle coiling components are arranged opposite each other. Correspondingly, the connecting plate is provided with top plates on both sides along the third direction that correspond to the positions of the arc-shaped grooves.

[0019] In the above solution, by providing two arc-shaped grooves symmetrically arranged on both sides of the connecting plate along the third direction on each of the winding needles, the winding needles can simultaneously punch multiple axial positions of the inner layer of the core to form permanent arc-shaped imprints, which further improves the support uniformity of the inner layer material of the core and more effectively prevents the generation of local sagging or wrinkles.

[0020] Optionally, the top plates on both sides of the connecting plate along the third direction are fixedly connected to the first connecting column and the second connecting column.

[0021] In the above solution, by fixing the top plates on both sides of the connecting plate along the third direction to the first connecting post and the second connecting post, the synchronous movement of the top plates on both sides can be achieved, ensuring the consistency and synchronicity of the movement of the top plates on both sides, ensuring the synchronous formation of the imprints on both sides, and improving manufacturing consistency.

[0022] Optionally, it further includes a first reset member and a second reset member; the first reset member is elastically connected between the first connecting post and the connecting plate; the second reset member is elastically connected between two second connecting posts arranged along the first direction.

[0023] In the above scheme, by setting the first reset member and the second reset member, when the ejection driving component drives the trapezoidal push block to push outward, the first arc plate and the second arc plate overcome the elastic force of the first reset member and the second reset member and extend out of the arc groove; when the ejection driving component removes the driving force, the elastic force of the first reset member and the second reset member drives the first arc plate and the second arc plate to automatically retract into the arc groove; the reset device has a simple structure and a fast response, and can realize the automatic retraction of the first arc plate and the second arc plate without additional active driving components, thereby avoiding scratching the inner wall of the core during core pulling.

[0024] Optionally, the sum of the arc lengths of all the coiled needles is C1, and the sum of the arc lengths of all the arc grooves is C2, wherein C2 ≥ C1 × 0.8.

[0025] In the above scheme, by limiting the sum of the arc lengths of all the winding needles to C1 and the sum of the arc lengths of all the arc grooves to C2, satisfying C2≥C1×0.8, the sagging deformation caused by gravity can be resisted more effectively, ensuring that the inner layer material of the core is tightly attached along the imprint, avoiding wrinkles, collapses or interlayer misalignment of the inner layer of the core, further improving the internal uniformity and interface stability of the battery cell, and enhancing the performance and reliability of the battery cell.

[0026] Optionally, the edges of the top plate are provided with rounded chamfers.

[0027] In the above solution, by setting the rounded chamfer at the edge of the top plate, the sharp edges of the top plate can be prevented from scratching the electrode or diaphragm during the extension or retraction process, thereby improving the winding yield. At the same time, the frictional resistance between the top plate and the arc groove is reduced, which improves the safety of the winding process and the smoothness of the top plate's movement.

[0028] Secondly, embodiments of this application provide a winding device, including the aforementioned battery cell winding mechanism.

[0029] This application provides a winding device including the aforementioned battery cell winding needle mechanism. A through arc-shaped groove is provided on the outer peripheral wall of the winding needle, and a retractable top plate is disposed within the arc-shaped groove. During or after winding, the top plate extends out of the arc-shaped groove to stamp the inner layer material of the core, forming a permanent arc-shaped imprint. This imprint acts as a structural reinforcing rib, effectively resisting sagging deformation caused by gravity and ensuring that the inner layer material of the core adheres tightly along the imprint. This prevents wrinkles, collapses, or interlayer misalignment in the inner layer of the core, improving the internal uniformity and interface stability of the battery cell, thereby enhancing the performance and reliability of the battery cell.

[0030] Thirdly, embodiments of this application provide a winding method applied to the aforementioned battery cell winding mechanism or winding equipment, comprising the following steps: S1: The driving device drives each of the coiling needles to move away from each other, so that the coiling needles are in an expanded state with an enlarged outer diameter; S2: Feed the positive electrode, negative electrode and separator into the winding station according to the preset order and tension; S3: Drive the winding needle to rotate around its central axis, causing the positive electrode sheet, negative electrode sheet and separator to be wound synchronously to form a preliminary core structure; S4: When the winding reaches the preset number of turns, the rotation of the winding needle is stopped; the ejection device drives the top plate to extend out of the arc groove, so that the outer end face of the top plate presses against the inner surface of the preliminary core structure, thereby forming a permanent arc-shaped imprint along the circumference in the inner layer of the preliminary core structure. S5: After stamping is completed, the ejector device drives the top plate to retract into the arc-shaped groove; S6: The driving device drives each of the winding needles to move closer to each other, so that the winding needles are in a contracted state with a reduced outer diameter, and then the winding needles are pulled out from the center hole of the core to complete the core unloading.

[0031] The winding method proposed in this application involves adding a step of extending the top plate for stamping, which stamps the inner layer material of the core to form a permanent arc-shaped imprint. This imprint serves as a structural reinforcing rib, effectively resisting sagging deformation caused by gravity and ensuring that the inner layer material of the core is tightly adhered along the imprint. This prevents wrinkles, collapses, or interlayer misalignment in the inner layer of the core, improves the internal uniformity and interface stability of the battery cell, and thus enhances the performance and reliability of the battery cell. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the overall structure of the battery cell winding mechanism (when the top plate retracts) in some embodiments of this application. Figure 1 ; Figure 2 This is a schematic diagram of the overall structure of the battery cell winding mechanism (when the top plate retracts) in some embodiments of this application. Figure 2 ; Figure 3 This is a front view of the cell winding mechanism (when the top plate is retracted) in some embodiments of this application; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a cross-section of the cell winding mechanism (when the top plate retracts) in some embodiments of this application. Figure 1 ; Figure 6 This is a cross-section of the cell winding mechanism (when the top plate retracts) in some embodiments of this application. Figure 2 ; Figure 7 This is a schematic diagram of the overall structure of the cell winding mechanism (when the top plate is open) in some embodiments of this application. Figure 1 ; Figure 8 This is a schematic diagram of the overall structure of the cell winding mechanism (when the top plate is open) in some embodiments of this application. Figure 2 ; Figure 9 This is a front view of the cell winding mechanism (with the top plate open) in some embodiments of this application; Figure 10 for Figure 9 Enlarged view at point B in the middle; Figure 11 This is a schematic diagram of the winding effect of the battery core made by the winding needle mechanism in some embodiments of this application.

[0034] [Explanation of Labels in the Attached Image] X: First direction; Y: Second direction; Z: Third-party direction; 1: Needle coil; 11: Needle coil component; 111: Outer peripheral wall; 112: Arc groove; 2: Drive unit; 21: Connecting plate; 22: Guide groove; 221: First guide groove; 222: Second guide groove; 223: First connecting post; 224: Second connecting post; 3: Ejector device; 31: Top plate; 311: First arc-shaped plate; 312: Second arc-shaped plate; 313: Trapezoidal groove; 32: Ejector drive component; 33: Trapezoidal push block; 331: Pulley; 4: First reset component; 5: Second reset component. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0037] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0040] In this application, "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0041] The cell winding needle mechanism, as the core actuator in the winding equipment, is mainly used to support, position, and guide the electrode sheets and separators to form a preset contour during the winding process. The cell winding needle mechanism typically includes a retractable winding needle and a drive unit connected to it. The winding needle provides the basic winding contour and support surface for the electrode sheets and separators; the drive unit, as the power source, controls the opening and closing of the winding needle using cylinders or motors to achieve diameter changes during the winding process. A typical winding method is roughly as follows: first, the separator and electrode sheets are introduced and positioned on the winding needle in an open state; then, the winding needle rotates, driving multiple layers of material to be wound synchronously to form a core; after winding to a set number of turns, the drive unit controls the winding needle to retract, causing it to detach from the inner wall of the core; finally, the winding needle is pulled out from the center of the core (referred to as core pulling), completing one winding cycle.

[0042] However, in the actual production process of the core, after the winding is completed and the drive unit drives the winding needle to retract and complete the core pulling, the inner layer material of the core will sag and deform under its own gravity due to the loss of the mechanical support of the winding needle. This phenomenon is particularly significant in the innermost ring area of ​​the core, which causes the separator and the electrode to be unable to maintain the original tight fit. This results in irreversible wrinkles, collapses or interlayer misalignments inside the core, directly affecting the internal uniformity and interface stability of the cell, causing a decline in the overall performance of the cell, and may even lead to safety hazards.

[0043] In view of this, to avoid wrinkles, collapses, or interlayer misalignment of the inner layers of the battery core due to sagging and deformation of the inner layer material, and to improve the internal uniformity and interface stability of the battery core, thereby enhancing its performance and reliability, this application provides a battery core winding mechanism, winding equipment, and winding method. The vertical direction of the battery core winding mechanism is defined as the first direction X, the horizontal direction as the second direction Y, and the front-back direction as the third direction Z. The specific scheme is as follows: Example 1 This application provides a battery cell winding mechanism, such as... Figure 1 , Figure 2 , Figure 3 As shown, the battery cell winding mechanism includes a winding needle 1, a driving device 2, and an ejection device 3, specifically: The needle coil 1 includes a plurality of needle coiling components 11 arranged sequentially along the circumference. Each needle coiling component 11 has an outer peripheral wall 111, and the outer peripheral wall 111 is provided with a through arc-shaped groove 112 along the circumference. Specifically, the number of needle coiling components 11 can be two, three, or four, etc., and there is no limitation here.

[0044] The driving device 2 is used to drive each of the needle coiling parts 11 to move closer or further away from each other; specifically, the driving device 2 can use a cylinder, motor or hydraulic cylinder or other driving method to realize the radial movement of the needle coiling parts 11 so as to move closer or further away from each other, and there is no limitation here.

[0045] The ejector device 3 includes a plurality of top plates 31 disposed inside the coiling needle 1 and corresponding to the position of the arc groove 112; the top plate 31 is inserted into the corresponding arc groove 112, the outer end face of the top plate 31 is an arc shape matching the corresponding arc groove 112, and can extend out of the arc groove 112 or retract into the arc groove 112. Specifically, the number of top plates 31 can correspond one-to-one with the arc-shaped grooves 112, that is, one top plate 31 is inserted into one arc-shaped groove 112, and the position and length of the top plate 31 correspond to the arc-shaped groove 112. Alternatively, multiple top plates 31 can correspond to one arc-shaped groove 112, that is, multiple top plates 31 are inserted into one arc-shaped groove 112, such as 2, 3, 4, etc., as long as the position and total length of all the top plates 31 in one arc-shaped groove 112 correspond to the position and length of the arc-shaped groove 112 and can extend outside the arc-shaped groove 112, there is no limitation here. Of course, the top plate 31 and the arc-shaped groove 112 can adopt a clearance fit to ensure smooth sliding, there is no limitation here.

[0046] This application provides a battery cell winding mechanism, which involves providing a through arc-shaped groove 112 on the outer peripheral wall 111 of the winding needle 1, and arranging a retractable top plate 31 within the arc-shaped groove 112. During or after winding, as... Figure 7 , Figure 8 , Figure 9 As shown, by controlling the top plate 31 to extend beyond the arc-shaped groove 112, as... Figure 11 As shown, a permanent arc-shaped imprint can be formed on the inner layer material of the core by stamping. This imprint acts as a structural reinforcing rib, which can effectively resist the sagging deformation caused by gravity and ensure that the inner layer material of the core is tightly attached along the imprint. This avoids wrinkles, collapses or interlayer misalignment of the inner layer of the core, improves the internal uniformity and interface stability of the battery cell, and thus enhances the performance and reliability of the battery cell.

[0047] In the verification experiment, the sum of the arc lengths of all the coiled needle parts 11 was set to C1 = 300 mm. When the sum of the arc lengths of all the arc grooves 112 was C2 = 210 mm (at this time, C2 = C1 × 0.7), the sum of the lengths of the permanent arc-shaped imprints formed by stamping within the inner layer material of the core was also 210 mm. At this time, the imprints could resist the sagging deformation caused by gravity, and no wrinkles, collapses, or interlayer misalignments occurred in the inner layer of the core. When the sum of the arc lengths of all the arc grooves 112 was C2 = 240 mm (at this time, C2 = C1 × 0.8), the sum of the lengths of the permanent arc-shaped imprints formed by stamping within the inner layer material of the core was also 240 mm. At this time, the imprints... It can also effectively resist sagging deformation caused by gravity, and the inner layer of the core does not have problems such as wrinkles, collapse or interlayer misalignment, and the effect is even better; when the sum of the arc lengths of all the arc grooves 112 is C2=270mm (at this time C2=C1×0.9), the sum of the lengths of the permanent arc imprints formed by stamping in the inner layer material of the core is also 270mm. At this time, the imprint can effectively resist sagging deformation caused by gravity, and the inner layer of the core does not have problems such as wrinkles, collapse or interlayer misalignment, and the effect is further improved. It can maximize the length of the permanent arc imprint while taking into account the structural strength of the coil needle 1; therefore, preferably, C1×0.9≥C2≥C1×0.8.

[0048] In other embodiments, the number of the needle coiling pieces 11 is two, and the two needle coiling pieces 11 are arranged opposite each other along the first direction X.

[0049] In the above scheme, by setting the winding needle 11 as two semi-circular structures arranged opposite each other along the first direction X, it is convenient to realize the rapid opening and closing of the winding needle 1, simplify the structural design of the driving device 2, improve the core pulling efficiency and equipment reliability; at the same time, it can ensure the uniformity of the support of the winding needle 1 to the electrode sheet and diaphragm during the winding process, and improve the roundness consistency of the core.

[0050] In other embodiments, the top plate 31 includes a first arcuate plate 311 and a second arcuate plate 312 arranged opposite to each other along the second direction Y; such as Figure 4As shown, the adjacent sides of the first arc-shaped plate 311 and the second arc-shaped plate 312 gradually move outwards and form an included angle α, forming a trapezoidal groove 313 inwards; along the first direction X from the outside to the inside, the inner diameter of the trapezoidal groove 313 gradually increases, and the included angle between the two side walls of the trapezoidal groove 313 is β1; the ejection device 3 also includes an ejection driving component 32 and a trapezoidal push block 33; the included angle between the two side walls of the trapezoidal push block 33 is β2, and β2-β1=α; the trapezoidal push block 33 is installed in the trapezoidal groove 313, and under the drive of the ejection driving component 32, it can move along the first direction X to abut or move away from the inner wall of the trapezoidal groove 313. Specifically, the ejection driving component 32 can be a cylinder, motor, or hydraulic cylinder, etc., and there is no limitation here.

[0051] In the above scheme, by setting the top plate 31 as a first arc-shaped plate 311 and a second arc-shaped plate 312 arranged opposite to each other along the second direction Y, and making their adjacent sides gradually move away from each other to form an included angle α, forming a trapezoidal groove 313 inward, with the included angle between the two side walls of the trapezoidal groove 313 being β1, and simultaneously making the included angle β2 between the two side walls of the trapezoidal push block 33 greater than β1, and satisfying β2-β1=α, when the ejection driving component 32 pushes the trapezoidal push block 33 to move along the first direction X to abut against the inner wall of the trapezoidal groove 313, since β2>β1, the side wall of the trapezoidal push block 33 generates a component force that pushes outward along the second direction Y against the two inner walls of the trapezoidal groove 313, such as... Figure 10 As shown, the first arc plate 311 and the second arc plate 312 not only push outward along the first direction X, but also unfold outward synchronously, so that the tops of the two gradually approach each other, the included angle α gradually disappears, and finally they are spliced ​​into a continuous arc surface. This structure can realize the synchronous and symmetrical pushing out of the first arc plate 311 and the second arc plate 312, and finally form a circumferentially continuous and uniformly deep arc-shaped imprint in the inner layer of the core. This significantly improves the forming quality of the imprint and the uniformity of the force on the inner layer of the core, which can further improve the internal uniformity and interface stability of the battery cell, and improve the performance and reliability of the battery cell.

[0052] In other embodiments, the angle range of β1 is 19°–39°, and the angle range of β2 is 20°–40°. Specifically, the angles of β1 and β2 can be selected according to the size of the coil needle 1 and the required ejection stroke, and are not limited here.

[0053] In the above scheme, by limiting β1 and β2 within the above angle range, it is ensured that the trapezoidal pusher 33 can generate sufficient thrust component along the second direction Y to drive the top plate 31 to extend during the movement, and the self-locking or frictional increase caused by excessive angle is avoided, thus ensuring that the ejection device 3 operates smoothly and reliably.

[0054] In other embodiments, such as Figure 4 As shown, the trapezoidal push block 33 has a plurality of pulleys 331 on its side wall. Preferably, the pulleys 331 can be evenly arranged along the length of the side wall of the trapezoidal push block 33, and the pulleys 331 and the side wall of the trapezoidal push block 33 can be connected by a pivot shaft, which is not limited here.

[0055] In the above scheme, by setting the pulley 331 on the side wall of the trapezoidal push block 33, the sliding friction between the trapezoidal push block 33 and the inner wall of the trapezoidal groove 313 can be converted into rolling friction, which significantly reduces frictional resistance, makes the ejection and retraction actions smoother, reduces component wear, and improves the service life and action sensitivity of the ejection device 3.

[0056] In other embodiments, such as Figure 5 , Figure 6As shown, the needle coiling component 11 is provided with a connecting plate 21 connected to the output end of the driving device 2; the connecting plate 21 is provided with two sets of guide grooves 22, and the two sets of guide grooves 22 are arranged in a one-to-one correspondence with the first arc plate 311 and the second arc plate 312, that is, one set of guide grooves 22 corresponds to the first arc plate 311, and the other set of guide grooves 22 corresponds to the second arc plate 312; wherein, the guide groove 22 includes a first guide groove 221 and a second guide groove 222; the first guide groove 221 extends along the first direction X and is located on the first arc plate. The first guide groove 221 is slidably connected to the first arc plate 311 or the second arc plate 312 on one side near the trapezoidal groove 313; the first connecting post 223 is fixedly connected to the first arc plate 311 or the second arc plate 312 within the first guide groove 221; the second guide groove 222 is arc-shaped with its center located at the end of the first guide groove 221 away from the center of the coiling needle 1; the second connecting post 224 is slidably connected to the second guide groove 222 within the second guide groove 222, and the second connecting post 224 is fixedly connected to the first arc plate 311 or the second arc plate 312. Specifically, the first connecting post 223 and the second connecting post 224 can be fixedly connected to the first arc plate 311 or the second arc plate 312 by means of threaded connection, welding, or integral molding, etc., which is not limited here. When the ejection drive component 32 drives the first arc plate 311 and the second arc plate 312 to move, the first connecting post 223 slides along the first guide groove 221 and the second connecting post 224 slides along the second guide groove 222, thereby limiting the movement trajectory of the first arc plate 311 and the second arc plate 312.

[0057] In the above scheme, by setting a composite guiding structure of the first guide groove 221 and the second guide groove 222, the movement trajectory of the first arc plate 311 and the second arc plate 312 can be precisely constrained. Specifically, the first guide groove 221 extends along the first direction X, ensuring the movement accuracy of the first arc plate 311 and the second arc plate 312 along the first direction X during extension and retraction; the second guide groove 222 is arc-shaped and its center is located at one end away from the center of the winding needle 1, ensuring the rotational movement accuracy of the first arc plate 311 and the second arc plate 312 as they extend outward, thereby ensuring that their outer end faces always fit well with the inner wall of the winding core, ensuring uniform and consistent imprint depth.

[0058] In other embodiments, each of the needle coiling components 11 is provided with two arc-shaped grooves 112 symmetrically arranged on both sides of the connecting plate 21 along the third direction Z. The arc-shaped grooves 112 of all the needle coiling components 11 are arranged opposite to each other. Correspondingly, the connecting plate 21 is provided with top plates 31 on both sides along the third direction Z, corresponding to the positions of the arc-shaped grooves 112. For example, when there are two needle coiling components 11, each of the needle coiling components 11 is provided with two arc-shaped grooves 112, and the two arc-shaped grooves 112 are symmetrically arranged along the third direction Z.

[0059] In the above scheme, by providing two arc-shaped grooves 112 symmetrically arranged on both sides of the connecting plate 21 along the third direction Z on each of the winding needles 11, the winding needles 1 can simultaneously punch multiple axial positions of the inner layer of the core to form permanent arc-shaped imprints, which further improves the support uniformity of the inner layer material of the core and more effectively prevents the generation of local sagging or wrinkles.

[0060] In other embodiments, the top plate 31 on both sides of the connecting plate 21 along the third direction Z is fixedly connected to the first connecting post 223 and the second connecting post 224.

[0061] In the above solution, by fixing the top plates 31 on both sides of the connecting plate 21 along the third direction Z to the first connecting post 223 and the second connecting post 224, the synchronous movement of the top plates 31 on both sides can be achieved, ensuring the consistency and synchronicity of the movement of the top plates 31 on both sides, ensuring the synchronous formation of the imprints on both sides, and improving manufacturing consistency.

[0062] In some embodiments, the battery cell winding mechanism further includes a first reset member 4 and a second reset member 5; the first reset member 4 is elastically connected between the first connecting post 223 and the connecting plate 21; the second reset member 5 is elastically connected between two second connecting posts 224 arranged along the first direction X. Specifically, the first reset member 4 and the second reset member 5 can be springs, sheet metal, or rubber elastomers, etc., and there are no limitations here. One end of the first reset member 4 is connected to the first connecting post 223, and the other end is connected to the connecting plate 21, for driving the first connecting post 223 to reset along the first guide groove 221 after the ejection driving component 32 removes the driving force. The two ends of the second reset member 5 are respectively connected to two second connecting posts 224 arranged opposite to each other along the first direction X, for driving the two second connecting posts 224 to move closer to each other after the ejection driving component 32 removes the driving force; thereby driving the first arc plate 311 and the second arc plate 312 to retract into the arc groove 112 to complete the reset.

[0063] In the above scheme, by setting the first reset member 4 and the second reset member 5, when the ejection driving member 32 drives the trapezoidal push block 33 to push outward, the first arc plate 311 and the second arc plate 312 overcome the elastic force of the first reset member 4 and the second reset member 5 and extend out of the arc groove 112; when the ejection driving member 32 removes the driving force, the elastic force of the first reset member 4 and the second reset member 5 drives the first arc plate 311 and the second arc plate 312 to automatically retract into the arc groove 112; the reset device has a simple structure and a fast response, and can realize the automatic retraction of the first arc plate 311 and the second arc plate 312 without additional active driving members, thereby avoiding scratching the inner wall of the core during core pulling.

[0064] In other embodiments, the edge of the top plate 31 is provided with a rounded chamfer. Specifically, the radius of the rounded chamfer can be selected according to the thickness of the top plate 31 and the size of the arc groove 112, for example, 0.2mm, 0.5mm or 1mm, etc., and is not limited here.

[0065] In the above solution, by setting the rounded chamfer at the edge of the top plate 31, the sharp edge of the top plate 31 can be prevented from scratching the electrode or diaphragm during the extension or retraction process, thereby improving the winding yield. At the same time, the frictional resistance between the top plate 31 and the arc groove 112 is reduced, which improves the safety of the winding process and the smoothness of the top plate 31's movement.

[0066] Example 2 This application also provides a winding device, including the cell winding needle mechanism described in Embodiment 1 above. Specifically, the winding device may further include conventional components such as an unwinding mechanism, a tension control mechanism, a cutting mechanism, and a feeding mechanism, which will not be described in detail here.

[0067] This application provides a winding device including the aforementioned battery cell winding needle mechanism. A penetrating arc-shaped groove 112 is provided on the outer peripheral wall 111 of the winding needle 1, and a retractable top plate 31 is disposed within the arc-shaped groove 112. During or after winding, the top plate 31 extends out of the arc-shaped groove 112 to press the inner layer material of the core, forming a permanent arc-shaped imprint. This imprint serves as a structural reinforcing rib, effectively resisting sagging deformation caused by gravity and ensuring that the inner layer material of the core adheres tightly along the imprint. This prevents wrinkles, collapses, or interlayer misalignment in the inner layer of the core, improving the internal uniformity and interface stability of the battery cell, thereby enhancing the performance and reliability of the battery cell.

[0068] Example 3 This application also provides a winding method, applied to the cell winding mechanism in Embodiment 1 or the winding equipment in Embodiment 2, the winding method specifically including the following steps: S1: The driving device 2 drives each of the coiling needles 11 to move away from each other, so that the coiling needle 1 is in an expanded state with an enlarged outer diameter; S2: Feed the positive electrode, negative electrode and separator into the winding station according to the preset order and tension; S3: Drive the winding needle 1 to rotate around its central axis, causing the positive electrode sheet, negative electrode sheet and diaphragm to be wound synchronously to form a preliminary core structure; S4: After the preset number of turns is reached, the rotation of the winding needle 1 is stopped; the ejector device 3 drives the top plate 31 to extend out of the arc-shaped groove 112, so that the outer end face of the top plate 31 presses against the inner surface of the preliminary core structure, thereby forming a permanent arc-shaped imprint along the circumference in the inner layer of the preliminary core structure; specifically, the preset number of turns can be set according to the design requirements of the battery cell, and is not limited here. The depth of the permanent arc-shaped imprint can be adjusted by controlling the extension amount of the top plate 31.

[0069] S5: After the stamping is completed, the ejector device 3 drives the top plate 31 to retract into the arc-shaped groove 112; S6: The driving device 2 drives each of the winding needle pieces 11 to move closer to each other, so that the winding needle 1 is in a contracted state with a reduced outer diameter, and then the winding needle 1 is pulled out from the center hole of the core to complete the core unloading.

[0070] The winding method proposed in this application involves adding a step of extending the top plate 31 for stamping, which stamps the inner layer material of the core to form a permanent arc-shaped imprint. This imprint serves as a structural reinforcing rib, effectively resisting sagging deformation caused by gravity and ensuring that the inner layer material of the core is tightly adhered along the imprint. This prevents wrinkles, collapses, or interlayer misalignment in the inner layer of the core, improves the internal uniformity and interface stability of the battery cell, and thus enhances the performance and reliability of the battery cell.

[0071] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0072] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0073] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0074] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell winding mechanism, characterized in that, include: The coiled needle (1) includes a plurality of coiled needle components (11) arranged sequentially along the circumference. Each of the coiled needle components (11) includes an outer peripheral wall (111), and the outer peripheral wall (111) is provided with a through arc-shaped groove (112) along the circumference. Drive device (2) is used to drive each of the coiled needle pieces (11) to move closer or further apart from each other; The ejector device (3) includes a plurality of top plates (31) disposed inside the coiling needle (1) and corresponding to the position of the arc groove (112); the top plate (31) is inserted into the corresponding arc groove (112), the outer end face of the top plate (31) is an arc shape matching the corresponding arc groove (112), and can extend out of the arc groove (112) or retract into the arc groove (112).

2. The battery cell winding mechanism according to claim 1, having a first direction (X), a second direction (Y), and a third direction (Z) that are perpendicular to each other, is characterized in that, Two needle coiling pieces (11) are provided, and the two needle coiling pieces (11) are arranged opposite each other along the first direction (X).

3. The battery cell winding mechanism according to claim 2, characterized in that, The top plate (31) includes a first arc-shaped plate (311) and a second arc-shaped plate (312) arranged opposite to each other along the second direction (Y); the adjacent sides of the first arc-shaped plate (311) and the second arc-shaped plate (312) gradually move away from each other outward and form an included angle α, and form a trapezoidal groove (313) inward; along the first direction (X) from the outside to the inside, the inner diameter of the trapezoidal groove (313) gradually increases, and the included angle between the two side walls of the trapezoidal groove (313) is β1; The ejection device (3) further includes an ejection drive component (32) and a trapezoidal push block (33); the included angle between the two side walls of the trapezoidal push block (33) is β2, and β2-β1=α; the trapezoidal push block (33) is installed in the trapezoidal groove (313), and can move along the first direction (X) under the drive of the ejection drive component (32) to abut or move away from the inner wall of the trapezoidal groove (313).

4. The battery cell winding mechanism according to claim 3, characterized in that, The angle range of β1 is 19°-39°, and the angle range of β2 is 20°-40°.

5. The battery cell winding mechanism according to claim 3, characterized in that, The trapezoidal pusher (33) has several pulleys (331) on its side wall.

6. The battery cell winding mechanism according to claim 3, characterized in that, The needle coiling component (11) is provided with a connecting plate (21) connected to the output end of the driving device (2); the connecting plate (21) is provided with two sets of guide grooves (22), and the two sets of guide grooves (22) are arranged in a one-to-one correspondence with the first arc plate (311) and the second arc plate (312); The guide groove (22) includes a first guide groove (221) and a second guide groove (222); the first guide groove (221) extends along the first direction (X) and is located on the side of the first arc plate (311) or the second arc plate (312) near the trapezoidal groove (313); a first connecting post (223) is slidably connected in the first guide groove (221), and the first connecting post (223) is fixedly connected to the first arc plate (311) or the second arc plate (312); The second guide groove (222) is arc-shaped and its center is located at one end of the first guide groove (221) away from the center of the coiling needle (1); a second connecting post (224) is slidably connected in the second guide groove (222), and the second connecting post (224) is fixedly connected to the first arc plate (311) or the second arc plate (312).

7. The battery cell winding mechanism according to claim 6, characterized in that, Each of the needle coiling components (11) is provided with two arc-shaped grooves (112) symmetrically arranged on both sides of the connecting plate (21) along the third direction (Z). The arc-shaped grooves (112) of all the needle coiling components (11) are arranged opposite to each other. Correspondingly, the connecting plate (21) is provided with top plates (31) on both sides along the third direction (Z) that correspond to the positions of the arc-shaped grooves (112).

8. The battery cell winding mechanism according to claim 7, characterized in that, The top plates (31) on both sides of the connecting plate (21) along the third direction (Z) are fixedly connected to the first connecting post (223) and the second connecting post (224).

9. The battery cell winding mechanism according to claim 6, characterized in that, It also includes a first reset member (4) and a second reset member (5); the first reset member (4) is elastically connected between the first connecting post (223) and the connecting plate (21); the second reset member (5) is elastically connected between two second connecting posts (224) arranged along the first direction (X).

10. The battery cell winding mechanism according to claim 1, characterized in that, The sum of the arc lengths of all the coiled needles (11) is C1, and the sum of the arc lengths of all the arc grooves (112) is C2, wherein C2 ≥ C1 × 0.

8.

11. The battery cell winding mechanism according to any one of claims 1 to 10, characterized in that, The edge of the top plate (31) is provided with rounded chamfers.

12. A winding device, characterized in that, Includes the cell winding mechanism as described in any one of claims 1 to 10.

13. A winding method, characterized in that, Applied to the cell winding mechanism as described in any one of claims 1 to 11 or the winding equipment as described in claim 12, Includes the following steps: S1: The driving device (2) drives each of the coiling needles (11) to move away from each other, so that the coiling needle (1) is in an expanded state with an enlarged outer diameter; S2: Feed the positive electrode, negative electrode and separator into the winding station according to the preset order and tension; S3: Drive the winding needle (1) to rotate around its central axis, thereby driving the positive electrode sheet, negative electrode sheet and diaphragm to wind synchronously and form a preliminary core structure; S4: When the winding reaches the preset number of turns, stop the rotation of the winding needle (1); the ejection device (3) drives the top plate (31) to extend out of the arc groove (112), so that the outer end face of the top plate (31) presses the inner surface of the preliminary core structure, thereby forming a permanent arc-shaped imprint along the circumferential direction in the inner layer of the preliminary core structure. S5: After the stamping is completed, the ejector device (3) drives the top plate (31) to retract into the arc groove (112); S6: The driving device (2) drives each of the winding needle pieces (11) to move closer to each other, so that the winding needle (1) is in a contracted state with a reduced outer diameter, and then the winding needle (1) is pulled out from the center hole of the core to complete the core unloading.

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