Battery cell winding system and battery cell winding process

Abstract

The invention provides a battery cell winding system, and relates to the technical field of battery cell winding, and the battery cell winding system comprises an unwinding mechanism which comprises a pole piece unwinding device used for providing a pole piece for a downstream mechanism and a diaphragm unwinding mechanism used for providing a diaphragm for the downstream mechanism; the continuing subsystem is located at the downstream of the unwinding mechanism and used for cutting the pole pieces into pole piece sections and connecting the adjacent pole piece sections into a continuous pole piece material belt through a connecting belt; the continuous winding subsystem comprises a compounding mechanism and a winding needle mechanism which are located at the downstream of the continuous subsystem, and the compounding mechanism is used for compounding a connecting belt and a diaphragm to form a composite structure belt; and the winding needle mechanism is used for fly-cutting and winding the composite structure belt to form a battery cell. According to the battery cell winding system provided by the invention, continuous sheet feeding and winding of more than 2000mm / s can be realized, and the winding efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery winding, in particular to a battery cell winding system and a battery cell winding process. BACKGROUND

[0002] In the existing winding production, according to the structure of the battery cell, the pole piece needs to be cut off and separated during the running process to form a certain gap between the adjacent two winding cores, and then continue to run to the winding needle mechanism to fly cut and wind to form a battery cell. This is one of the more common and efficient technologies. However, due to the need to stop or slow down cutting when cutting the pole piece, the cut pole piece no longer has continuity, and the entire winding production process is difficult to truly realize high-speed and continuous winding. In order to realize non-stop cutting of the pole piece, a chasing mechanism is proposed in the prior art, but the existing chasing mechanism is usually only suitable for lower pole piece running speed. At high speed, such as a pole piece running speed of 1000mm / s or more, the pole piece is prone to deviation and displacement. At the same time, the existing connecting belt connecting mechanism for connecting the cut pole piece has the problems of difficult positioning of the connecting belt, the need for slow connection of the belt, and poor continuity of the pole piece material line, which limits the improvement of winding efficiency. SUMMARY

[0003] The purpose of the present application is to provide a battery cell winding system that can realize high-speed and continuous winding.

[0004] Another purpose of the present application is to provide a battery cell winding process.

[0005] The present application discloses a battery cell winding system, comprising: A winding-off mechanism, comprising a pole piece winding-off device for providing a pole piece to a downstream mechanism and a separator winding-off mechanism for providing a separator to a downstream mechanism; A splicing subsystem, located downstream of the winding-off mechanism, for cutting the pole piece to form a pole piece segment and connecting adjacent pole piece segments into a continuous pole piece material belt through a connecting belt; A continuous winding subsystem, comprising a composite mechanism and a winding needle mechanism located downstream of the splicing subsystem, the composite mechanism being used to composite the connecting belt with the separator to form a composite structure belt; and the winding needle mechanism being used to fly cut and wind the composite structure belt to form a battery cell.

[0006] Further, in some embodiments of the present application, the pole piece material belt is continuously and uniformly fed into the winding needle mechanism.

[0007] Further, in some embodiments of the present application, the pole piece winding-off device comprises a positive pole piece winding-off device for winding a positive pole piece and a negative pole piece winding-off device for winding a negative pole piece; The splicing subsystem includes a first splicing subsystem and a second splicing subsystem, the first splicing subsystem is arranged downstream of the positive electrode sheet unwinding device, and the second splicing subsystem is arranged downstream of the negative electrode sheet unwinding device. The composite mechanism includes a first composite device for splicing the connecting belt / septum of the first splicing subsystem with the connecting belt / septum in the second splicing subsystem to form a composite structure belt.

[0008] Further, in some embodiments of the present application, the septum unwinding mechanism includes a first septum unwinding mechanism for unwinding a first septum and a second septum unwinding mechanism for unwinding a second septum. The cell winding system further includes a second composite device and a third composite device, the second composite device and the third composite device are respectively located upstream of the first composite device, the second composite device is used for splicing the first septum unwound by the first septum unwinding mechanism with the positive electrode sheet material belt formed by the first splicing subsystem; and the third composite device is used for splicing the second septum unwound by the second septum unwinding mechanism with the negative electrode sheet material belt formed by the second splicing subsystem.

[0009] Further, in some embodiments of the present application, the first splicing subsystem and the second splicing subsystem each include a sheet feeding adjustment device, a sheet cutting and feeding mechanism, and a belt splicing mechanism. The sheet feeding adjustment device is located downstream of the sheet unwinding device and is used for adjusting the feeding speed of the electrode sheet fed to the downstream mechanism. The sheet cutting and feeding mechanism is located downstream of the sheet feeding adjustment device and includes a cutting device and a moving sheet feeding device, the cutting device is used for cutting the electrode sheet to form an electrode sheet segment; and the moving sheet feeding device reciprocally moves along the direction of the electrode sheet segment and simultaneously feeds the electrode sheet segment into the downstream mechanism by using the roller feeding and linear sheet feeding modes. The belt splicing mechanism is located downstream of the cutting device and is used for connecting the adjacent electrode sheet segments fed by the moving sheet feeding device by using the connecting belt.

[0010] Further, in some embodiments of the present application, the sum of the speed of the electrode sheet segment fed by the roller in the sheet cutting and feeding mechanism and the speed of the electrode sheet segment fed by the linear sheet feeding is equal to the speed of the electrode sheet segment fed into the belt splicing mechanism, and the electrode sheet segment uniformly travels in the belt splicing mechanism.

[0011] Further, in some embodiments of the present application, the sheet feeding adjustment device includes an adjusting assembly and a driving roller. The adjusting assembly is located upstream of the sheet cutting and feeding mechanism and is used for absorbing the tension of the electrode sheet in the sheet cutting and feeding mechanism or providing tension for the electrode sheet in the sheet cutting and feeding mechanism. The active roller is located upstream or downstream of the adjusting assembly and is used to deliver the pole piece to the pole piece cutting and feeding mechanism.

[0012] Further, in some embodiments of the present application, the adjusting assembly comprises an adjusting roller and an adjusting driver used to drive the adjusting roller to move.

[0013] Further, in some embodiments of the present application, the adjusting roller is located downstream of the active roller; and the adjusting driver is used to drive the adjusting roller to reciprocate along a straight line parallel to the running direction of the pole piece.

[0014] Further, in some embodiments of the present application, the adjusting assembly further comprises a buffer and a moving member arranged between the adjusting roller and the adjusting driver. One end of the buffer is connected to the moving member, and the other end is connected to the adjusting roller; the adjusting driver drives the moving member, the buffer and the adjusting roller to reciprocate. The pole piece contacts the side of the adjusting roller away from the buffer.

[0015] Further, in some embodiments of the present application, the feeding adjusting device further comprises a tension detecting member; the tension detecting member is located between the adjusting roller and the moving feeding device and is used to detect the tension change of the pole piece. The adjusting driver drives the adjusting roller to move according to the tension change of the pole piece detected by the tension detecting member.

[0016] Further, in some embodiments of the present application, the moving feeding device comprises a first feeding device and a second feeding device. The first feeding device is located upstream of the cutting device; the first feeding device reciprocates between the feeding adjusting device and the tape receiving mechanism and is used to feed the cut pole piece into the tape receiving mechanism according to the spacing between adjacent pole pieces. The second feeding device is located downstream of the cutting device; the second feeding device reciprocates between the feeding adjusting device and the tape receiving mechanism. The first feeding device and the second feeding device are used to feed the cut pole piece into the tape receiving mechanism according to the spacing between adjacent pole pieces.

[0017] Further, in some embodiments of the present application, the first feeding device comprises a first feeding roller used to roll the pole piece and a first linear driver used to drive the first feeding roller to reciprocate along the running direction of the pole piece. The second feeding device comprises a second feeding roller used to roll the pole piece and a second linear driver used to drive the second feeding roller to reciprocate along the running direction of the pole piece.

[0018] Further, in some embodiments of the present application, the first sheet feeding roller comprises a first sheet feeding roller A and a first sheet feeding roller B respectively located on two sides of the pole piece, and a first roller feeding driver for driving the first sheet feeding roller A and / or the first sheet feeding roller B to rotate; The second sheet feeding roller comprises a second sheet feeding roller A and a second sheet feeding roller B respectively located on two sides of the pole piece, and a second roller feeding driver for driving the second sheet feeding roller A and / or the second sheet feeding roller B to rotate.

[0019] Further, in some embodiments of the present application, the first linear driver drives the first sheet feeding roller to reciprocate along the direction of movement of the pole piece; The second linear driver drives the second sheet feeding roller to reciprocate along the direction of movement of the pole piece; The feeding speed of the first sheet feeding device is equal to the sum of the moving speed of the first linear driver in the direction of movement of the pole piece and the roller feeding speed of the first sheet feeding roller; The feeding speed of the second sheet feeding device is equal to the sum of the moving speed of the second linear driver in the direction of movement of the pole piece and the roller feeding speed of the second sheet feeding roller.

[0020] Further, in some embodiments of the present application, the first sheet feeding device moves synchronously with the cutting device.

[0021] Further, in some embodiments of the present application, the cutting device and the first sheet feeding device are mounted on the same moving platform; the first linear driver drives the moving platform to reciprocate along the direction of movement of the pole piece.

[0022] Further, in some embodiments of the present application, the connecting tape receiving mechanism comprises: A connecting tape feeding device for feeding the connecting tape to the pole piece segment; A flying cutting device for cutting the connecting tape to form a connecting tape; A positioning transfer device comprising a positioning transfer roller and a first positioning member arranged on the positioning transfer roller; the first positioning member is used for positioning the tail of the connecting tape; A connecting tape receiving device comprising a compound roller for receiving the connecting tape sent by the positioning transfer roller and compounding on the surface of the adjacent pole piece segment.

[0023] Further, in some embodiments of the present application, the flying cutting device comprises a flying knife, a first driver for driving the flying knife to move, a pressure roller, and a second driver for driving the pressure roller to move close to or away from the positioning transfer roller; The pressure roller is located upstream of the flying knife.

[0024] Further, in some embodiments of the present application, the first positioning member is a fly-cutting groove arranged on the positioning adapter roller, and the fly-cutting groove is arranged in cooperation with the fly cutter.

[0025] Further, in some embodiments of the present application, the positioning adapter device further comprises a third driver for driving the positioning adapter roller to approach or move away from the composite roller.

[0026] Further, in some embodiments of the present application, the vertical distance between the composite roller and the pole piece is less than the vertical distance between the positioning adapter roller and the pole piece.

[0027] Further, in some embodiments of the present application, the composite roller, the positioning adapter roller and the pressing roller are all vacuum suction rollers with a plurality of vacuum suction holes arranged on the outer circumferential surface of the vacuum suction rollers.

[0028] Further, in some embodiments of the present application, the composite device further comprises a fifth driver for driving the composite roller to approach or move away from the pole piece.

[0029] Further, in some embodiments of the present application, the tape connecting mechanism further comprises a tension buffer device arranged upstream of the fly-cutting device, for absorbing the tension of the connecting tape or providing tension to the connecting tape.

[0030] Further, in some embodiments of the present application, the distance between the first composite device and the tangent point between the composite structure tape and the winding needle is 50-100 mm.

[0031] Further, in some embodiments of the present application, the first composite device is an electrostatic generator.

[0032] In a second aspect, the present application further provides an electric core winding process, which adopts the electric core winding system of the first aspect to wind the electric core, and the electric core winding process comprises a winding-off process, a pole piece connection process and a continuous winding process. The winding-off process comprises synchronously performed positive pole piece winding-off process and negative pole piece winding-off process, and synchronously performed first separator winding-off process and second separator winding-off process. The electrode splicing process includes a positive electrode splicing process and a negative electrode splicing process performed simultaneously. The positive electrode splicing process includes cutting the positive electrode sheet unwound from the positive electrode sheet unwinding process into positive electrode segments while traveling at a constant speed, and connecting the two adjacent positive electrode segments into a continuous positive electrode strip using a connecting belt fed at the same speed after the distance between them is increased to the target distance. The negative electrode splicing process includes cutting the negative electrode sheet unwound from the negative electrode sheet unwinding process into negative electrode segments while traveling at a constant speed, and connecting the two adjacent negative electrode segments into a continuous negative electrode strip using a connecting belt fed at the same speed after the distance between them is increased to the target distance. The continuous winding process includes a continuous composite process and a winding process; the continuous composite process includes combining the positive electrode strip, the first separator, the negative electrode strip, and the second separator into a composite structure layer; the winding process includes feeding the composite structure layer into a winding machine for winding, cutting, and starting to wind the next cell.

[0033] Furthermore, in some embodiments of this application, the positive and negative electrode segments formed by the cutting process both travel at a constant speed before entering the winding machine.

[0034] Furthermore, in some embodiments of this application, the travel speed of the cut-out positive and negative electrode segments before entering the winding machine is not less than 2000 mm / s.

[0035] Furthermore, in some embodiments of this application, the positive electrode splicing process includes: S211: The positive electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the positive electrode sheet to form a positive electrode segment. The cut positive electrode segment continues to move at a constant speed to approach the connecting mechanism. S212 increases the roller feeding speed of the positive electrode segment and decreases the linear feeding speed of the positive electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the positive electrode segment, until the linear feeding speed of the positive electrode segment is 0, and the positive electrode segment is fed into the tape receiving mechanism. S213: First decelerate the cut positive electrode sheet and then accelerate it to increase the distance between it and the positive electrode segment to the preset distance, and make the travel speed of the head of the cut positive electrode sheet the same as the travel speed of the positive electrode segment; repeat steps S211 and S212. The positive electrode splicing process and the negative electrode splicing process are performed in parallel and simultaneously; The negative electrode splicing process includes: S221: The negative electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the negative electrode sheet to form a negative electrode segment. The cut negative electrode segment continues to move at a constant speed to approach the tape-connecting mechanism. S222 increases the roller feeding speed of the negative electrode segment and decreases the linear feeding speed of the negative electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the negative electrode segment, until the linear feeding speed of the negative electrode segment is 0, and the negative electrode segment is fed into the tape receiving mechanism. S223: First slow down the cut negative electrode sheet and then accelerate it to increase the distance between it and the negative electrode segment to the preset distance, and make the travel speed of the head of the cut negative electrode sheet the same as the travel speed of the negative electrode segment; repeat steps S221 and S222.

[0036] Furthermore, in some embodiments of this application, a positive electrode sheet adjustment process and a negative electrode sheet adjustment process are respectively provided upstream of the positive electrode sheet connection process and the negative electrode sheet connection process; The positive electrode adjustment process is used to actively adjust the feeding speed and tension of the positive electrode entering the positive electrode splicing process; The negative electrode adjustment process is used to actively adjust the feeding speed and tension of the negative electrode entering the negative electrode splicing process.

[0037] Furthermore, in some embodiments of this application, the average unwinding speed of the positive electrode unwinding process is lower than the travel speed of the positive electrode segment; the average unwinding speed of the negative electrode unwinding process is lower than the travel speed of the negative electrode segment. The unwinding speed of the first diaphragm unwinding process and the second diaphragm unwinding process is equal to the travel speed of the positive electrode segment / negative electrode segment.

[0038] Furthermore, in some embodiments of this application, the continuous composite process includes a first composite process, a second composite process, and a third composite process; the first composite process includes composited positive electrode strip with the first separator unwound in the first separator unwinding process; the second composite process includes composited negative electrode strip with the second separator unwound in the second separator unwinding process; and the third composite process includes composited the connecting strip / separator on the positive electrode strip with the connecting strip / separator on the negative electrode strip.

[0039] Furthermore, in some embodiments of this application, the first composite process, the second composite process, and the third composite process are all electrostatic composite processes.

[0040] The beneficial effects of this application are: The battery cell winding system and process provided in this application employ a specific splicing subsystem, which allows the electrode to be cut into electrode segments during the uniform speed travel of the electrode sheet, and maintains its travel speed to connect with the connecting strip to form a continuous electrode splice. Then, it is continuously fed into the winding needle mechanism while maintaining its travel speed. This achieves the technical effects of cutting the electrode sheet without slowing down, conveying without slowing down, and splicing without slowing down, enabling the battery cell winding system to achieve continuous winding without slowing down in the cutting and splicing sections at speeds of 2000 mm / s or higher.

[0041] The splicing subsystem includes an electrode feeding device that adjusts the electrode feeding speed and tension before the electrode cutting and feeding mechanism. Simultaneously, a moving feeding device stabilizes the head and tail of the cut electrode before it enters the splicing mechanism, reducing the degrees of freedom at the head and tail of the electrode segment. Furthermore, when the electrode enters the receiving mechanism, a pre-cut and positioned connecting strip is used to splice the electrode through a rolling roller, forming a continuous electrode material. This achieves continuity in the electrode feeding, cutting, spacing, and splicing processes, while avoiding electrode displacement, ribbon slippage, and wrinkling. It also reduces resistance during electrode acceleration, exceeding the upper limits of electrode acceleration and deceleration, and effectively supports increasing electrode travel speed and reducing the required system workspace. Furthermore, this cell winding system ensures stable electrode travel and minimizes ribbon slippage, electrode deviation, and wrinkling during high-speed, continuous winding. Attached Figure Description

[0042] Fig. 1 A schematic diagram of the structure of a battery cell winding system provided in some embodiments of this application; Fig. 2 A schematic diagram of the feeding adjustment device structure of a battery cell winding system provided in some embodiments of this application; Fig. 3 A schematic diagram of the structure of a cutting device, a first feeding device and a second feeding device of a cell winding system provided for some embodiments of this application; Fig. 4 A schematic diagram of the tape-connecting mechanism of a battery cell winding system provided for some embodiments of this application; Among them, 101-positive electrode sheet, 102-negative electrode sheet, 103-first diaphragm, 104-second diaphragm, 105-connecting belt, 110-positive electrode sheet unwinding device, 120-negative electrode sheet unwinding device, 130-first diaphragm unwinding mechanism, 140-second diaphragm unwinding mechanism, 210-cutting device, 220-connecting belt mechanism, 221-composite roller, 222-positioning transfer roller, 223-first positioning component, 225-flying knife 226-Pressure roller, 227-Swing roller, 228-Defective strip winding device, 230-First feeding device, 231-First feeding roller A, 232-First feeding roller B, 240-Second feeding device, 241-Second feeding roller A, 242-Second feeding roller B, 250-Feeding adjustment device, 251-Adjusting roller, 252-Drive roller, 253-Detection roller, 310-Composite mechanism, 320-Needle winding mechanism. Detailed Implementation

[0043] To better explain the present invention, detailed descriptions are provided with reference to the embodiments of the present invention, and the main contents of the present invention are further clarified in conjunction with specific embodiments. However, the contents of the present invention are not limited to the following embodiments.

[0044] In the description of this application, it should be understood that the terms "thickness," "upper," "lower," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the term "a plurality of" means two or more, unless otherwise explicitly defined.

[0045] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0046] The term "uniform speed feeding" as used in this application refers to the fact that the electrode conveying speed is uniform relative to the next stage of the follow-up cutting stage, rather than variable speed conveying. It does not mean that the electrode conveying speed remains constant throughout the follow-up cutting stage or even the previous stage before the follow-up cutting stage.

[0047] The "follow-cutting section" mentioned in this application refers to the movement from the starting end of the first feeding device in the electrode travel direction to the moving end of the second feeding device in the electrode travel direction, hereinafter referred to as the "starting end" and the "end," respectively. Therefore, the first feeding device, the cutting device, and the second feeding device reciprocate between the starting end and the end to feed the electrode. It should also be noted that an electrode conveying main shaft is located near the follow-cutting section in the next section for conveying the electrode.

[0048] In this application, "positive electrode segment" refers to the electrode segment formed after the positive / negative electrode sheet is cut by a cutting device; "negative electrode segment" refers to the electrode segment formed after the negative / positive electrode sheet is cut by a cutting device; when the positive electrode segment is a positive electrode segment, the negative electrode segment is a negative electrode segment, and when the positive electrode segment is a negative electrode segment, the negative electrode segment is a positive electrode segment. In this application, "positive electrode sheet" refers to the electrode sheet remaining before the positive / negative electrode sheet is cut or after it has been cut to form an electrode segment; "negative electrode sheet" refers to the electrode sheet remaining before the negative / positive electrode sheet is cut or after it has been cut to form an electrode segment.

[0049] The term "second pole segment" refers to the pole segment located downstream of the cutting device, while the term "second pole segment" refers to the pole segment located upstream of the cutting device that will be formed after the next cutting action. The end of the first pole segment closest to the second pole segment is the tail of the first pole segment, and the end of the second pole segment closest to the tail of the first pole segment is the head of the second pole segment. The distance between the first and second pole segments is the distance from the tail of the first pole segment to the head of the second pole segment.

[0050] In this application, "velocity" includes both numerical value and direction. When two "velocities" are the same, it usually means that they are equal in value and have the same direction.

[0051] In this application, the term "roller," such as positioning transfer rollers, composite rollers, and pressure rollers, when described as needing to rotate, should be understood as being connected to a rotation drive device, such as a rotary motor, to drive its rotation. The conventional drivers required for the rotation of the roller, as well as the connection structure between these drivers and the roller, are all prior art. Therefore, even if the rotation drive device connected to it is not explicitly described in this application, those skilled in the art can know from common knowledge or conventional technical means that in implementing this application, it is necessary to connect a driver to drive the rotation of the roller in order to make it rotate. Therefore, it will not be described in detail in this application.

[0052] The applicant found that existing continuous winding systems face numerous limitations if further increases in winding speed are required. For example, the electrode feeding resistance is high, making it difficult to achieve rapid adjustments under the high acceleration and deceleration required during follow-up cutting, thus limiting the upper limit and adjustment of the feeding speed in the follow-up cutting section. Furthermore, after the electrode is cut into segments, the degrees of freedom at the head and tail of the segments increase, significantly exacerbating belt slippage, offset, and wrinkling during high-speed feeding. Additionally, if the cut electrodes are not connected using connecting belts, the electrode material strip is discontinuous, making high-speed continuous conveying difficult. However, using current connecting belt methods requires speed reduction and stopping for belt reconnection, or inaccurate belt reconnection positioning, further hindering high-speed, continuous winding. Based on this, the applicant proposes a cell winding system in this application, which includes a movable feeding device in the tape receiving mechanism. This movable feeding device feeds the cut electrode segments into the tape receiving mechanism. The discontinuous electrode segments cut into segments are compensated for by the continuously moving feeding device, thus achieving continuous feeding of the electrode segments. This solves the problem of continuous electrode feeding between the cutting device and the tape receiving mechanism, improves feeding efficiency, and solves other problems caused by the discontinuity of the cut electrode segments.

[0053] Specifically, the battery cell winding system, see [link to documentation]. Figs. 1-4 ,include: The unwinding mechanism includes an electrode unwinding device for providing electrode sheets to a downstream mechanism and a diaphragm unwinding mechanism for providing diaphragms to a downstream mechanism. The splicing subsystem includes a section located downstream of the unwinding mechanism for cutting the electrode sheet into electrode segments and connecting adjacent electrode segments into a continuous electrode strip via a connecting belt. The continuous winding subsystem includes a composite mechanism 310 and a winding needle mechanism 320 located downstream of the connecting subsystem. The composite mechanism 310 is used to combine the connecting strip and the diaphragm to form a composite structure strip; the winding needle mechanism 320 is used to cut and wind the composite structure strip to form a battery cell.

[0054] In this system, the electrode strip is continuously and uniformly fed into the composite mechanism and the needle winding mechanism in the continuous winding subsystem. That is, the electrode strip neither slows down nor stops when it is fed into the composite mechanism 310 and the needle winding mechanism 320.

[0055] In order to enable the electrode strip to be continuously and uniformly fed into the composite mechanism and the winding needle mechanism to achieve continuous winding, each electrode strip forming path in this application is provided with a splicing subsystem, and each splicing subsystem includes a feeding adjustment device for feeding the electrode downstream and adjusting the feeding speed, an electrode cutting feeding mechanism for cutting the electrode fed by the feeding adjustment device and feeding it downstream at a uniform speed, and a splicing mechanism for splicing the cut electrode segments during uniform speed travel. The electrode cutting and feeding mechanism includes a moving feeding device and a cutting device 210. The moving feeding device reciprocates along the traveling direction of the electrode segment and simultaneously uses roller feeding and linear feeding methods to feed the electrode segment into the downstream mechanism. Before and after the electrode is cut, the moving feeding device restricts the degrees of freedom of the head of the next electrode segment and the tail of the previous electrode segment until it is fed into the tape-connecting mechanism at a uniform speed. This avoids the electrode segment being difficult to feed downstream at high speed due to increased degrees of freedom after being cut. The tape-connecting mechanism includes a composite roller for attaching a connecting tape to the tail of the previous electrode segment and the head of the next electrode segment, avoiding the electrode segment slowing down or becoming discontinuous during the connection process. In addition, the feeding adjustment device actively adjusts the electrode feeding speed upstream of the electrode cutting and feeding mechanism. This avoids the problem of rapid deceleration and acceleration of the electrode segment required to increase the spacing between the electrode segments during the follow-up cutting process, which is difficult to meet the high-speed requirements due to the passive absorption of tension changes by the buffer device. This also avoids the problem of needing to slow down for follow-up cutting.

[0056] Since the battery cell includes a positive electrode and a negative electrode, the electrode unwinding device includes a positive electrode unwinding device 110 for unwinding the positive electrode 101 and a negative electrode unwinding device 120 for unwinding the negative electrode 102. Correspondingly, the diaphragm unwinding mechanism includes a first diaphragm unwinding mechanism 130 for unwinding the first diaphragm 103 and a second diaphragm unwinding mechanism 140 for unwinding the second diaphragm 104.

[0057] Since both the positive and negative electrode sheets need to be cut and then rejoined, the rejoining subsystem includes a first rejoining subsystem and a second rejoining subsystem. The first rejoining subsystem is located downstream of the positive electrode sheet unwinding device, and the second rejoining subsystem is located downstream of the negative electrode sheet unwinding device. Both the first and second rejoining subsystems include a feeding adjustment device 250 for feeding the electrode sheets downstream and adjusting the feeding speed, an electrode sheet cutting and feeding mechanism for cutting the electrode sheets fed by the feeding adjustment device 250 and feeding them downstream at a uniform speed, and a rejoining mechanism 220 for splicing the cut electrode segments during their uniform travel.

[0058] The electrode strips formed after splicing include positive electrode strips and negative electrode strips. The composite mechanism is located downstream of the first splicing subsystem and the second splicing subsystem. It is a first composite device used to combine the connecting strip of the first splicing subsystem, the first diaphragm, the connecting strip of the second splicing subsystem, and the second diaphragm to form a composite structure strip.

[0059] In some embodiments, the cell winding system further includes a second composite device and a third composite device, which are located upstream of the first composite device. The second composite device is used to composite the first diaphragm unwound by the first diaphragm unwinding mechanism with the positive electrode strip formed by the first splicing subsystem. The third composite device is used to composite the second diaphragm unwound by the second diaphragm unwinding mechanism with the negative electrode strip formed by the second splicing subsystem.

[0060] The composite structure strip formed after the composite process enters the winding mechanism, where it is cut and wound to form a battery cell.

[0061] The travel speed of the electrode segment remains constant after the cutting device 210, in the attaching mechanism 220, and in the composite mechanism 310. Preferably, the travel speed of the electrode segment after the cutting device, in the attaching mechanism, and in the composite mechanism is not less than 2000 mm / s.

[0062] The feeding adjustment device described in this application can be of various types, as long as it can actively adjust the speed of the electrode sheets fed into the electrode sheet cutting feeding mechanism. To facilitate understanding and implementation by those skilled in the art, two examples are provided below, based on the different positions of the active roller and the adjustment assembly used to feed the electrode sheets to the cutting device: <Part 1> The electrode feeding adjustment device 250 is located upstream of the mobile electrode feeding device and is used to actively adjust the length, speed, and tension of the electrode during feeding. The electrode feeding adjustment device includes a drive roller 252, an adjustment roller 252, and an adjustment driver for driving the adjustment roller to move.

[0063] The electrode conveying length of the active roller is equal to the length of the electrode conveyed by the moving electrode feeding device, and the electrode feeding speed of the active roller is equal to the electrode feeding speed of the moving electrode feeding device. The regulating roller is located upstream of the driving roller and is used to absorb the tension changes of the electrode sheet during the acceleration and deceleration conveying process. The regulating driver is used to drive the regulating roller to reciprocate in a straight line parallel to the traveling direction of the electrode, thereby absorbing or providing tension to the electrode.

[0064] The electrode feeding adjustment device further includes a detection roller 253; the detection roller 253 is located between the drive roller 252 and the cutting device, and is used to detect the tension change of the electrode sheet; the drive roller adjusts the electrode sheet feeding speed according to the tension detected by the detection roller. If the detection roller detects a rapid drop in tension when the electrode sheet is cut, the drive roller slows down to feed the electrode sheet to the moving electrode feeding device, and at the same time, the adjustment driver drives the adjustment roller away from the adjustment driver to provide tension to the electrode sheet.

[0065] In some embodiments, no other active rollers besides the detection roller are provided between the active roller and the moving feeding device. This reduces the resistance experienced by the electrode during acceleration and deceleration, preventing the electrode from experiencing significant resistance that would hinder rapid acceleration and deceleration, and allowing for a larger space required for the follow-up cutting and separation spacing in the follow-up cutting section. Furthermore, a driven roller that facilitates electrode detection or transport can be added between the active roller and the moving feeding device.

[0066] In this electrode feeding adjustment device, an active roller located upstream of the moving electrode feeding device is used to actively adjust the feeding speed of the electrode, reducing the resistance encountered by the electrode during acceleration and deceleration. In addition, an upstream device is set to absorb the tension changes when the active roller adjusts the feeding speed of the electrode, providing support for the high-speed feeding of the electrode.

[0067] <Part Two> The electrode feeding adjustment device is located upstream of the first electrode feeding device and includes an adjustment component and a drive roller; the adjustment component is located upstream of the first electrode feeding device and is used to absorb electrode tension or provide tension to the electrode; the drive roller is located upstream of the adjustment component and is used to feed the electrode to the first electrode feeding device.

[0068] The adjustment assembly includes an adjustment roller, a moving part, an adjustment driver, and a buffer part disposed between the adjustment roller and the adjustment driver. One end of the buffer part is connected to the moving part, and the other end is connected to the adjustment roller. The adjustment driver drives the moving part, the buffer part, and the adjustment roller to reciprocate. The electrode contacts the side of the adjustment roller away from the buffer part. The adjustment driver drives the moving part to reciprocate along a certain moving track. During the cutting of the electrode and the adjustment of the adjustment roller, the buffer part can buffer the electrode tension, thereby achieving more stable electrode transport. In this application, the buffer part can be any buffer part that can achieve compression and reset, such as a buffer spring. The adjustment driver can be any existing driver such as an electric driver, a pneumatic driver, or a hydraulic driver. The moving direction of the moving part is determined according to the contact position between the electrode and the adjustment roller. The moving direction of the moving part is perpendicular to the centerline of the contact surface between the electrode and the adjustment roller and the tangent of the adjustment roller, so as to push the adjustment roller to absorb or supplement the electrode tension.

[0069] Since the buffer typically buffers the displacement of the moving part driven by the adjustment driver relative to the adjustment roller, the electrode conveying length of the active feeding roller is equal to the sum of the electrode length received by the moving part, the electrode length absorbed by the buffer, and the electrode conveying length of the first feeding device. The mathematical signs of the electrode length received by the moving part and the electrode length absorbed by the buffer are opposite.

[0070] In this example, the electrode feeding adjustment device also includes a detection roller; the detection roller is located between the adjustment assembly and the cutting device, and is used to detect changes in the tension of the electrode sheet; the drive roller adjusts the electrode sheet feeding rate according to the tension detected by the detection roller. If the detection roller detects a rapid drop in tension when the electrode sheet is cut, the drive roller slows down to feed the electrode sheet to the first electrode feeding roller group, while the adjustment driver drives the adjustment roller away from the adjustment driver to provide tension to the electrode sheet.

[0071] In the above example, no other active rollers besides the detection roller are provided between the active roller and the first feeding device. This reduces the resistance experienced by the electrode during acceleration and deceleration, preventing the electrode from experiencing significant resistance that would hinder rapid acceleration and deceleration. This also allows for a larger space required for the follow-up cutting and separation spacing in the follow-up cutting section. Furthermore, a driven roller that facilitates tension detection or prevents electrode vibration can be provided between the active roller and the moving feeding device.

[0072] In this application, the electrode sheet is cut into electrode segments and then combined with a separator to form a composite structure strip. Since the separator is a continuous strip, the overall travel speed of the electrode sheet is crucial for the high-speed, continuous operation of the winding system. To achieve high-speed, continuous winding of the battery cell, stable feeding is required before the cutting device. The feeding adjustment device provided in this application can solve the feeding speed limitation caused by the high acceleration and deceleration of the electrode sheet during high-speed, non-deceleration cutting, resulting in high feeding resistance and poor stability. It feeds the electrode sheet to the moving feeding device under stable tension, providing support for high-speed, non-deceleration cutting of the electrode sheet. The battery cell winding system has a feeding adjustment device upstream of the moving feeding device, which can adjust the feeding speed of the electrode sheet fed into the cutting device and absorb the changes in electrode sheet tension caused by cutting, deceleration, and acceleration.

[0073] In this application, the electrode cutting and feeding mechanism is equipped with a moving feeding device, which moves between the beginning and end of the cutting section. After the electrode is cut, the increased degree of freedom of the tail of the first electrode segment formed after cutting and before the tape-connecting mechanism is restricted by the moving feeding device, so that it remains substantially unchanged compared to before cutting. After being fed into the tape-connecting mechanism, it is then restricted by the connecting tape. The degree of freedom of the head of the second connecting tape is also restricted by the moving feeding device, and it is fed into the tape-connecting mechanism while maintaining its restricted state, and then restricted by the connecting tape. Therefore, in the cell winding system provided by this application, the degrees of freedom of the tail of the first electrode segment and the head of the second electrode segment are always restricted, so that they are continuously fed by the moving feeding device, providing continuity for the discontinuous electrode segments. This solves the problem of discontinuous electrode segment feeding from the cutting device to the tape splicing mechanism, which easily leads to problems such as tape flying, offset, and wrinkles. It also solves the problem that the head of the cut electrode segment is prone to displacement during the deceleration process after being cut.

[0074] The movable feeding device includes a first feeding device 230 and a second feeding device 240. The first feeding device 230 is located upstream of the cutting device 210 and reciprocates between the feeding adjustment device 250 and the connecting mechanism 220 to feed the cut electrode sheet into the connecting mechanism according to the spacing between adjacent electrode sheets. The second feeding device 240 is located downstream of the cutting device 210 and reciprocates between the feeding adjustment device 250 and the connecting mechanism 220. The first and second feeding devices are used to feed the cut electrode sheet into the connecting mechanism according to the spacing between adjacent electrode sheets.

[0075] The first feeding device includes a first feeding roller for rolling the electrode sheet and a first linear driver for driving the first feeding roller to reciprocate along the traveling direction of the electrode sheet. The second feeding device includes a second feeding roller for rolling the electrode sheet and a second linear driver for driving the second feeding roller to reciprocate along the traveling direction of the electrode sheet.

[0076] The first feeding roller includes a first feeding roller A 231 and a first feeding roller B 232 located on both sides of the electrode sheet. The first linear driver synchronously drives the first feeding roller A 231 and the first feeding roller B 232 to reciprocate along the traveling direction of the electrode sheet.

[0077] The first feeding device further includes a first roller driver, such as a rotary motor, that drives the first feeding roller A or the first feeding roller B to rotate. The first feeding roller A and the first feeding roller B are respectively disposed on both sides of the electrode sheet, and one of them is a driving roller that is connected to the output end of the first roller driver, while the other is a driven roller. The first feeding roller A and the first feeding roller B are in close contact with the electrode sheet to transport the electrode sheet.

[0078] The second feeding device includes a second linear driver and a second feeding roller; the second linear driver drives the second feeding roller to reciprocate along the traveling direction of the electrode; the second feeding roller includes a second feeding roller A 241 and a second feeding roller B 242 located on both sides of the electrode, and the second linear driver synchronously drives the second feeding roller A 241 and the second feeding roller B 242 to reciprocate along the traveling direction of the electrode.

[0079] The second feeding roller also includes a second roller driver, such as a rotary motor, for driving the second feeding roller A or the second feeding roller B to rotate. The second feeding roller A and the second feeding roller B are respectively disposed on both sides of the electrode sheet, and one of them is a driving roller that is connected to the output end of the second roller driver, and the other is a driven roller. The second feeding roller A and the second feeding roller B are in close contact with the electrode sheet to transport the electrode sheet.

[0080] In other embodiments, the first feeding device further includes a first longitudinal driver that drives the first feeding roller A or the first feeding roller B to move perpendicular to the electrode travel direction, so that the first feeding roller A and the first feeding roller B are pressed against the electrode to transport the electrode; or so that the first feeding roller A and the first feeding roller B are released from the electrode. The second feeding device further includes a second longitudinal driver that drives the second feeding roller A or the second feeding roller B to move perpendicular to the electrode travel direction, so that the second feeding roller A and the second feeding roller B are pressed against the electrode to transport the electrode; or so that the second feeding roller A and the second feeding roller B are released from the electrode and return to the starting end of the follow-up cutting section. The starting end of the follow-up cutting section is the end near the feeding adjustment device.

[0081] While the first feeding roller feeds the electrode sheet, the first linear driver can drive the first feeding roller to reciprocate along the electrode sheet's travel direction. Therefore, the feeding speed of the first feeding device is equal to the sum of the moving speed of the first linear driver in the electrode sheet's travel direction and the feeding speed of the first feeding roller. Similarly, while the second feeding roller feeds the electrode sheet, the second linear driver can drive the second feeding roller to reciprocate along the electrode sheet's travel direction. Therefore, the feeding speed of the second feeding device is equal to the sum of the moving speed of the second linear driver in the electrode sheet's travel direction and the feeding speed of the second feeding roller.

[0082] The first linear driver and the second linear driver are respectively driving devices that drive the first feeding roller and the second feeding roller to reciprocate along the electrode traveling direction. Specifically, any commercially available device that can realize the reciprocating movement of the first feeding roller and the second feeding roller along the electrode traveling direction can be used, such as a linear motor. Other driving devices that can realize the reciprocating movement of the first feeding roller and the second feeding roller along the electrode traveling direction can also be used. Therefore, they will not be described in detail in this application.

[0083] The cutting device can be a blade cutting device or a laser cutting device. When the cutting device is a blade cutting device, it includes an upper cutter and a lower cutter, as well as a driving device for driving the upper cutter and the lower cutter to move closer to / away from the electrode sheet. The driving device can be an electric drive, a pneumatic drive, or a hydraulic drive.

[0084] It should be noted that the cutting device provided in this application is mounted on the same mounting platform as the first feeding roller group and moves along with the linear movement of the first feeding roller group. For example, its specific structure can be: The continuous feeding and cutting includes a linear moving track extending from the starting end to the ending end; a first mounting platform is slidably mounted on the linear moving track, the first feeding roller group is mounted on the first mounting platform, and the cutting device is also mounted on the mounting platform; a first mover drives the first mounting platform to move along the linear moving track; a second mounting platform is also provided on the linear moving track, the second feeding roller group is mounted on the second mounting platform, and a second mover drives the second mounting platform to move along the linear moving track.

[0085] In this application, the cutting device can be a linear path cutting component, wherein the driving device for driving the upper and lower cutters to approach / before the electrode sheet can be a linear driving device or a rotary driving device, such as a linear motor or a rotary motor.

[0086] The linear path tracking component is an existing straight path tracking component, such as its structure including an upper cutter, a lower cutter, a first drive mechanism for driving the upper cutter to move perpendicular to the electrode travel direction, and a second drive mechanism for driving the lower cutter to move perpendicular to the electrode travel direction. Furthermore, the linear path tracking component has the same moving speed as the electrode sheet, which is the same as the moving speed of the first and second driving mechanisms. The driving device for the reciprocating motion of the linear path tracking component along the electrode sheet's traveling direction can be the same as the first feeding device, or a separate linear driving device can be provided.

[0087] During the electrode cutting and feeding process: The first and second feeding devices accelerate from the starting end to the end as the electrode sheet moves, until it is accelerated to the required linear speed. This speed is maintained, and the electrode sheet is cut off by the cutting device. During this process, the roller speed of the first and second feeding devices can be zero or gradually increase as the feeding speed increases, but the sum of the roller speed and the linear speed is always equal to the traveling speed of the electrode sheet. Then, the roller speed and / or linear movement speed of the first feeding device decreases, causing the feeding speed of the second electrode segment to decrease. The second feeding device continues to feed the electrode at a constant speed, maintaining the roller speed and linear movement speed before cutting, so that the feeding speed of the first electrode segment remains high, widening the distance between the first and second electrode segments. When the distance between the first and second electrode segments reaches a preset distance (this preset distance is less than the required spacing between the electrode segments), the roller speed and / or linear movement speed of the first feeding device increases, causing the second electrode segment to accelerate until its travel speed equals that of the first electrode segment. During this stage, as the first electrode segment exits the follow-up cutting section, the linear movement speed of the second feeding device gradually decreases to 0, and the roller speed increases to the travel speed of the first electrode segment.

[0088] When the first feeding device approaches the second feeding device, the roller feeding speed of the first feeding device is accelerated, and the linear movement speed of the first feeding device is reduced until the linear movement speed of the first feeding device drops to 0 and the roller feeding speed of the first feeding device is equal to the electrode traveling speed, so that the head of the second electrode segment is conveyed to the second feeding device; at this time, the linear movement speed of the second feeding device is also 0 and the roller feeding speed is equal to the electrode traveling speed. The linear speed of the first and second feeding devices is increased in the opposite direction, causing them to move in a straight line relative to the direction of travel of the electrode sheet, without affecting the feeding of the electrode sheet. This continues until they approach the starting end. Then, the roller speed of the first and second feeding devices is reduced, and their linear reverse movement speed is also reduced until the linear movement speed of the first and second feeding devices reaches 0, allowing them to return to the starting end. During this process, the first feeding roller A or the first feeding roller B of the first feeding device and the second feeding roller A or the second feeding roller B of the second feeding device can be driven by a longitudinal driver to release the electrode sheet so as not to obstruct the feeding of the electrode sheet; alternatively, instead of using a longitudinal driver to release the electrode sheet, the roller feeding speed of the first feeding device and the second feeding device can be accelerated again while the linear movement speed of the first feeding device and the second feeding device is increased in the reverse direction, so that the roller feeding speed is higher than the reverse linear movement speed, thereby realizing the reverse movement of the electrode sheet and the first feeding device and the second feeding device. When the first feeding device and the second feeding device approach the starting end, the roller feeding speed and the linear movement speed are reduced until the linear movement speed is 0 and the roller feeding speed is equal to the electrode sheet travel speed, at which point the first feeding device and the second feeding device return to the starting end.

[0089] After the electrode is cut into electrode segments, it is fed into the connecting mechanism at a constant speed through the second feeding device. The connecting mechanism connects adjacent electrode segments into a continuous electrode strip through the connecting belt.

[0090] In this system, the tape-attaching mechanism 220 uses a composite roller 221 with a circular trajectory travel speed equal to that of the electrode segment to attach the connecting tape 105 to the tail of the first electrode segment and the head of the second electrode segment. In the moving feeding device, the moving feeding device moves to a second feeding roller near the tape-attaching mechanism 220, and the feeding speed is equal to that of the electrode segment, to feed the electrode segment into the tape-attaching mechanism. This allows for negligible release of the degrees of freedom at the tail and head of the electrode segment, and the tape-attaching mechanism can determine the starting position of the connecting tape attaching to the electrode segment based on the distance between the second feeding roller and the composite roller 221 of the tape-attaching mechanism. For example, when the second feeding roller approaches the composite roller of the tape-attaching mechanism, it drives the composite roller to accelerate to the same speed as the electrode segment and presses the electrode segment, simultaneously attaching the connecting tape adsorbed on the composite roller to the electrode segment. This reduces the space required for the winding system, making it more conducive to production and promotion.

[0091] Specifically, the receiving mechanism 220 includes: The belt feeding device is used to convey the connecting belt to the pole segment; A cutting device is used to cut the connecting strip to form a connecting strip; The positioning and transition device includes a positioning and transition roller 222 and a first positioning member 223 disposed on the positioning and transition roller 222; the first positioning member 223 is used to position the tail end of the connecting belt 105. The tape-connecting device includes a composite roller 221 for receiving the connecting tape 105 fed in by the positioning transfer roller 222 and bonding it to the surface of adjacent pole segments.

[0092] The belt feeding device can be a conventional belt conveyor, and the following structure can be adopted: The belt feeding device includes a belt feeding roller group and a drive motor for driving the belt feeding roller group to rotate; the belt feeding roller group includes a first belt feeding roller and a second belt feeding roller; the connecting belt passes between the first belt feeding roller and the second belt feeding roller, and is conveyed downstream through the first belt feeding roller and the second belt feeding roller; wherein at least one of the first belt feeding roller and the second belt feeding roller is a drive shaft connected to the output end of the drive motor.

[0093] Furthermore, an upstream connecting tape feeding device is provided in the tape feeding mechanism of the tape feeding mechanism provided in this application. This feeding device is similar to or the same as the diaphragm feeding device in the winding system of the battery cell, and therefore will not be described in detail here. The connecting tape provided in this application can be a diaphragm tape or a flexible porous connecting tape similar to a diaphragm. A diaphragm tape, i.e., a diaphragm tape consistent with the diaphragm used in the battery cell, is preferred. This avoids the introduction of impurities caused by the connecting tape material. Moreover, its physical and chemical properties are consistent with the diaphragm used in the battery cell, thus having no significant impact on the battery cell performance.

[0094] The flying cutter is located downstream of the feeding device and is used to cut the connecting strip. It includes a flying cutter 225, a first driver for moving the flying cutter, a pressure roller 226, and a second driver for moving the pressure roller 226 closer to or further away from the positioning transfer roller 222. The pressure roller 226 presses the connecting strip onto the positioning transfer roller 222, causing the connecting strip to adhere to the roller. The first driver drives the flying cutter closer to or further away from the positioning transfer roller. That is, when the connecting strip needs to be cut, the first driver drives the flying cutter closer to the positioning transfer roller to cut the connecting strip on the roller; when the connecting strip does not need to be cut, the first driver drives the flying cutter away from the positioning transfer roller, allowing the connecting strip on the roller to pass unobstructed. Therefore, the pressure roller is located upstream of the flying cutter, meaning the connecting strip is first pressed onto the positioning transfer roller and then cut by the flying cutter.

[0095] The positioning transfer roller is provided with a first positioning element 223, which can be a positioning groove provided on the positioning transfer roller 222. The size of the positioning groove matches the size of the flying knife 225 and the depth relative to the outer circumferential surface of the positioning transfer roller during cutting. The first positioning element can also serve as a flying cutting groove, which simultaneously performs the functions of flying cutting and positioning.

[0096] At this time, the positioning groove is used to position the tail of the connecting belt, so as to achieve the fixed length and positioning of the connecting belt.

[0097] The length of the connecting belt described in this application needs to be less than the sum of the circumference of the positioning transfer roller and the circumference of the composite roller. However, the belt-connecting mechanism provided in this application can be applied to the composite of connecting belts with a length less than the circumference of the positioning transfer roller, the composite of connecting belts with a length between the circumference of the positioning transfer roller and the circumference of the composite roller, and the composite of connecting belts with a length greater than the circumference of the composite roller. Furthermore, the length of the connecting belt can be adjusted within this wide range of the sum of the circumferences of the transfer roller and the composite roller, with almost no change in the required composite space, demonstrating good applicability.

[0098] In some embodiments, the positioning and transfer device further includes a third driver for driving the positioning and transfer roller closer to or away from the composite roller. When the positioning and transfer roller is driven closer to the composite roller, the connecting strip on the positioning and transfer roller is conveyed to the composite roller to prepare for the composite roller to laminate it onto the pole piece.

[0099] In this application, both the positioning transfer roller and the composite roller are vacuum adsorption rollers, that is, both the positioning transfer roller and the composite roller have a number of uniformly distributed vacuum holes on their outer circumferential surfaces. These vacuum holes are all connected to a vacuum machine to provide vacuum adsorption force for the positioning transfer roller and the composite roller.

[0100] The vacuum adsorption force of the composite roller is higher than that of the positioning transfer roller, allowing the connecting belt to be conveyed onto the composite roller. Furthermore, the transfer of the connecting belt from the positioning transfer roller to the composite roller can also be achieved by switching the vacuum pump connected to the positioning transfer roller on and off. The pressure roller can also be a vacuum adsorption roller. When the connecting belt is loosened and pressed onto the positioning transfer roller, the vacuum adsorption on the pressure roller is closed, and the connecting belt is absorbed by the tension buffer device until the head of the connecting belt returns to the pressure roller. Then, the vacuum adsorption on the pressure roller is activated to prepare for the subsequent feeding of the connecting belt onto the positioning transfer roller. When the pressure roller presses the connecting belt onto the positioning transfer roller, the vacuum adsorption on the pressure roller can be closed or adjusted to a state with a lower vacuum adsorption force compared to the positioning transfer roller.

[0101] In this application, the vertical distance between the composite roller and the electrode sheet is less than the vertical distance between the positioning transfer roller and the electrode sheet. The diameter of the positioning transfer roller can be equal to, greater than, or less than the diameter of the composite roller.

[0102] In this application, a tension buffer device is also provided upstream of the connecting belt flying cutter to absorb the tension of the connecting belt or to provide tension to the connecting belt. For example, when the positioning transfer roller reverses to the first positioning member returning to its initial position, the tension buffer device absorbs the connecting belt that returns due to the reversal of the positioning transfer roller. The tension buffer device is an existing buffer device that can achieve thin film tension buffering, such as the electrode buffer device in the cell winding system, so its structure will not be described in detail in this application.

[0103] After the cut electrode segments are connected by connecting strips to form a continuous strip, the electrode segments are composited with the separator to form a composite structure strip. The composite of the electrode segments and the separator can be achieved through electrostatic bonding or existing bonding methods, which will not be detailed in this application. It should also be noted that the electrode sheets in this application include positive and negative electrode sheets. Both the positive and negative electrode sheets are formed with the separator through processes such as cutting, spacing, and connecting to create a composite structure strip consisting of at least a positive electrode sheet, a separator, a negative electrode sheet, and a separator. Furthermore, the connecting strips between adjacent electrode segments form a multi-layer structure with at least two layers of connecting strips and two layers of separator.

[0104] When using the belt-connecting mechanism, the following usage method can be referenced: Rotate the positioning transfer roller to the position where the tail of the next connecting belt and the first positioning member are aligned with the flying cutter. The pressure roller presses the connecting belt onto the positioning transfer roller. The belt feeding device feeds pieces to the positioning transfer roller. Rotate the positioning transfer roller until the feeding length of the connecting belt is equal to the required length of the connecting belt. The connecting strip is cut using a flying cutter to form a connecting strip of a fixed length; The positioning transfer roller feeds the connecting belt into the composite roller; When the second feed roller is detected approaching the composite roller, the composite roller accelerates to the same speed as the traveling speed of the pole segment and moves down until it presses against the surface of the pole segment, thus bonding the connecting belt onto the adjacent pole segment. The connecting belt connects the tail of the previous pole segment with the head of the next pole segment. The composite roller then moves up and slows to 0, waiting for the next connecting belt to be fed in.

[0105] It should be noted that the first positioning member is used to position the tail of the connecting belt. Therefore, in this application, rotating the positioning transfer roller to align the tail of the next connecting belt, the first positioning member, and the flying cutter means that when the expected position of the tail of the next connecting belt is aligned with the first positioning member and the flying cutter at the desired connecting belt length, the head position of the next connecting belt is at the starting position where the moving pressure roller presses the connecting material belt onto the positioning transfer roller, and then rotating the positioning transfer roller to feed the connecting material belt until the desired connecting belt length is reached.

[0106] During this process, the positioning transfer roller is rotated in the opposite direction, and the pressure roller is moved to release the pressure roller and press the connecting strip onto the positioning connecting roller. The connecting strip is absorbed by the tension buffer device and returns to the pressure roller until the preset tail position of the next connecting strip, the first positioning piece and the flying cutter are aligned, and then the pressure roller is moved to press the connecting strip onto the corresponding head position of the connecting strip.

[0107] To avoid the impact of damaged or defective material in the connecting belt, this application also provides a defective material winding device and a first detection sensor in the connecting mechanism; The first detection sensor is located upstream of the positioning adapter and is used to detect whether the connecting strip is a defective strip. The defective tape winding device is located downstream of the positioning and transfer device and is used to wind up the detected defective tape.

[0108] The first detection sensor can be a photoelectric sensor, used to detect whether there are any damaged or excessively thin sections on the connecting strip, which could lead to breakage during or after the lamination process. Its detection mechanism can involve using the photoelectric sensor to detect the intensity or distribution of transmitted light. Alternatively, other sensors capable of detecting defects in the connecting strip can also be used.

[0109] The defective material strip winding device is located downstream of the positioning and transfer device and is used to wind up the defective material strip attached to the positioning and transfer roller and the composite roller. The defective material strip winding device includes a winding roller and a rotary motor that drives the winding roller to rotate, thereby winding the defective material strip onto the winding roller.

[0110] In some embodiments, the tape-connecting mechanism further includes a swinging device, which includes a swinging roller 227 and a fourth driver for driving the swinging roller 227 to move; the swinging roller 227 is used to peel the connected tape that is detected as a defective tape from the positioning transfer roller and send it into the defective tape winding device 228 when the connected tape is detected as a defective tape.

[0111] In this application, a tension buffer device is also provided upstream of the flying cutter of the tape-connecting mechanism to absorb electrode tension or provide tension to the electrode. For example, when the positioning transfer roller reverses to the first positioning member returning to its initial position, the tension buffer device absorbs the connecting tape that returns due to the reversal of the positioning transfer roller. The tension buffer device is an existing buffer device that can achieve thin film tension buffering, such as the electrode buffer device in the cell winding system, so its structure will not be described in detail in this application.

[0112] In some embodiments, to avoid the connecting tape from flying or wrinkling during the cutting process of the needle winding mechanism, the applicant also provides a first composite device disposed between the tape receiving mechanism and the needle winding mechanism. The first composite device is used to composite the diaphragm with the connecting tape.

[0113] The first composite device can be a hot press roller, a pressure roller, an electrostatic generator, or other composite devices to composite the diaphragm with the connecting belt.

[0114] In some embodiments, the first composite device is an electrostatic generator, which induces the connecting strip and the diaphragm, and the connecting strips to be attracted together. In addition, using an electrostatic generator as a second composite device can also ensure that when the connecting strip is connected to the electrode or the connecting strip is connected to the diaphragm, the connecting strip and the diaphragm travel or wind at the same speed and have the same tension. This can further reduce bubble formation and improve electrode bending, thereby further ensuring or even improving the electrical performance and quality stability of the wound cell.

[0115] Furthermore, the connecting strip is preferably a diaphragm, which not only possesses certain insulating properties, but also, since the connecting strip and the diaphragm are film layers of the same material, the wound cell formed by its winding does not actually introduce film layers of other materials / structures. Therefore, the performance of the wound cell is not affected by the introduction of other materials / structures; in addition, the ion penetration of the wound cell is also minimally affected. Simultaneously, since the tension of the connecting strip and the diaphragm is the same or infinitely close to the same, the composite structural layer formed by the electrode, connecting strip, and diaphragm during the winding process can greatly improve the travel speed.

[0116] Furthermore, by using an electrostatic generator to charge ions on the connecting strip and the diaphragm strip, they can be combined through electrostatic adsorption. This adsorption method does not require the introduction of any other impurity materials needed for the composite process, and it does not require pressure or heating on the connecting strip and the diaphragm, thus avoiding damage to the connecting strip and the diaphragm caused by pressure or heating, and avoiding damage to the electrical performance of the wound battery cell caused by pressure or heating. Furthermore, the applicant unexpectedly discovered that when the electrostatic generator controls the electrostatic adsorption strength between the connecting strip and the diaphragm to a certain level, and when the electrostatic generator sets the electrostatic composite position of the connecting strip and the diaphragm, the winding position of the winding needle, and the traveling speed of the electrode connecting section within a certain range, it can not only maintain the composite state between the connecting strips and between the connecting strips and the diaphragm at the required level, avoiding the decrease in electrostatic adsorption strength caused by the dissipation of charged ions, thus preventing the composite state between the connecting strips and between the connecting strips and the diaphragm from decreasing to the point where it cannot effectively improve the wrinkles and misalignments caused by the cutting and feeding of the electrode segment head; it can also prevent the tail of the previous electrode segment from swinging when it is wound to the tail, and the adsorption strength between the connecting strips and between the connecting strips and the diaphragm can be broken under the winding pressure, thereby causing a certain limited displacement, further reducing the possibility of wrinkles and misalignments.

[0117] It should be noted that, depending on the length of each electrode segment, the electrostatic generator can appropriately adjust the electrostatic adsorption strength between the connecting strip and the diaphragm. The position of the electrostatic generator relative to the cutting point of the winding needle can also be adjusted based on the electrostatic adsorption strength generated between the connecting strip and the diaphragm. Furthermore, the position of the electrostatic generator relative to the cutting point of the winding needle can also be adjusted according to the travel speed of the electrode connecting segment. The adjustment direction is as follows: the longer each electrode segment, the higher the electrostatic adsorption strength generated between the connecting strip and the diaphragm, and the closer the position of the electrostatic generator can be relative to the cutting point of the winding needle; the higher the travel speed of the electrode connecting segment, the higher the electrostatic adsorption strength generated between the connecting strip and the diaphragm, and the closer the position of the electrostatic generator can be relative to the cutting point of the winding needle.

[0118] In some embodiments, the line distance between the electrostatic generator and the cutting point of the composite structure tape and the winding needle is 50mm to 100mm, and the electrostatic adsorption force between adjacent connecting tapes or between the connecting tape and the diaphragm is controlled within the range of not less than 2500g.

[0119] Because the electrode connecting segments are spaced apart between adjacent electrode segments, the electrostatic generator acts intermittently on the connecting strip or diaphragm, causing it to be electrostatically attracted. The duration of each single operation of the electrostatic generator corresponds to the electrostatic attraction time of each electrode connecting segment.

[0120] In this application, adjacent electrode segments can be connected by a connecting strip located on one side of the electrode, or connecting strips can be provided on both sides of the electrode. Therefore, in this application, the total number of layers N of the electrode connection segment formed by the connecting strip and the diaphragm is usually 4 to 6 layers. The power of the electrostatic generator varies depending on the total number N of the electrode connection segment formed by the connecting strip and the diaphragm. The applicant has found that when the relationship between the operating voltage V (kV) of the electrostatic generator and the total number N of the connecting strip and diaphragm layers on the composite structure is controlled within the range of 7N ≤ V, the electrostatic adsorption force between adjacent connecting strips or between the connecting strip and the diaphragm can be controlled within the range of not less than 2500g, ensuring that the adsorption force between the connecting strips and between the connecting strip and the diaphragm meets the requirements.

[0121] Furthermore, in order to maximize the composite effect across the entire electrode connecting section and avoid wrinkles and displacement caused by gaps in the composite structure, the relationship between the single-cycle working time t of the connecting strip and the electrostatic generator, and the length of the connecting strip and the traveling speed of the composite structure strip, is controlled as follows: t = (L + l This range is ) / v; in l An additional distance of not less than 1 mm is required to ensure full-section composite between the connecting strips and between the connecting strips and the diaphragm.

[0122] More preferably, the supplementary distance l The compensation is applied at the tail of the previous electrode segment. That is, when the tail of the previous electrode segment is acquired by the sensor and the expected start-up time of the electrostatic generator is determined, the actual start-up time of the electrostatic emitter of the electrostatic generator is set to the expected start-up time minus the compensation distance. l / v; This means that the actual start-up time of the electrostatic emitter of the electrostatic generator is made up of the distance in advance based on the expected start-up time. l / v, to ensure that the entire electrode connection section is composite.

[0123] In some embodiments, the sensor is located upstream of the electrostatic generator, and the distance between the sensor and the electrostatic generator is a supplementary distance. l .

[0124] Furthermore, in this application, the unwinding mechanism and the winding needle mechanism are prior art. Those skilled in the art can selectively use other technical solutions of the winding needle mechanism that can realize the unwinding of electrode sheets, diaphragms and continuous winding of winding cells in the prior art, or selectively use the applicant's prior patents. Therefore, the specific structure will not be described in detail in this application.

[0125] Secondly, this application also provides a cell winding process, which uses the cell winding system described in the first aspect to wind the cell, and the cell winding process includes: an unwinding process, an electrode splicing process and a continuous winding process. The unwinding process includes a synchronous unwinding process for the positive electrode sheet and a synchronous unwinding process for the negative electrode sheet, as well as a synchronous unwinding process for the first diaphragm and a synchronous unwinding process for the second diaphragm. The electrode splicing process includes a positive electrode splicing process and a negative electrode splicing process performed simultaneously. The positive electrode splicing process includes cutting the positive electrode sheet unwound from the positive electrode sheet unwinding process into positive electrode segments while traveling at a constant speed, and connecting the two adjacent positive electrode segments into a continuous positive electrode strip using a connecting belt fed at the same speed after the distance between them is increased to the target distance. The negative electrode splicing process includes cutting the negative electrode sheet unwound from the negative electrode sheet unwinding process into negative electrode segments while traveling at a constant speed, and connecting the two adjacent negative electrode segments into a continuous negative electrode strip using a connecting belt fed at the same speed after the distance between them is increased to the target distance. The continuous winding process includes a continuous composite process and a winding process; the continuous composite process includes combining the positive electrode strip, the first separator, the negative electrode strip, and the second separator into a composite structure layer; the winding process includes feeding the composite structure layer into a winding machine for winding, cutting, and starting to wind the next cell.

[0126] Furthermore, in some embodiments of this application, the positive and negative electrode segments formed by the cutting process both travel at a constant speed before entering the winding machine.

[0127] Furthermore, in some embodiments of this application, the travel speed of the cut-out positive and negative electrode segments before entering the winding machine is not less than 2000 mm / s.

[0128] Furthermore, in some embodiments of this application, the positive electrode splicing process includes: S211: The positive electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the positive electrode sheet to form a positive electrode segment. The cut positive electrode segment continues to move at a constant speed to approach the connecting mechanism. S212 increases the roller feeding speed of the positive electrode segment and decreases the linear feeding speed of the positive electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the positive electrode segment, until the linear feeding speed of the positive electrode segment is 0, and the positive electrode segment is fed into the tape receiving mechanism. S213: First decelerate the cut positive electrode sheet and then accelerate it to increase the distance between it and the positive electrode segment to the preset distance, and make the travel speed of the head of the cut positive electrode sheet the same as the travel speed of the positive electrode segment; repeat steps S211 and S212. The positive electrode splicing process and the negative electrode splicing process are performed in parallel and simultaneously; The negative electrode splicing process includes: S221: The negative electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the negative electrode sheet to form a negative electrode segment. The cut negative electrode segment continues to move at a constant speed to approach the tape-connecting mechanism. S222: Increase the roller feeding speed of the negative electrode segment and decrease the linear feeding speed of the negative electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the negative electrode segment, until the linear feeding speed of the negative electrode segment is 0, and the negative electrode segment is fed into the tape receiving mechanism. S223: First slow down the cut negative electrode sheet and then accelerate it to increase the distance between it and the negative electrode segment to the preset distance, and make the travel speed of the head of the cut negative electrode sheet the same as the travel speed of the negative electrode segment; repeat steps S221 and S222.

[0129] Furthermore, in some embodiments of this application, a positive electrode sheet adjustment process and a negative electrode sheet adjustment process are respectively provided upstream of the positive electrode sheet connection process and the negative electrode sheet connection process; The positive electrode adjustment process is used to actively adjust the feeding speed and tension of the positive electrode entering the positive electrode splicing process; The negative electrode adjustment process is used to actively adjust the feeding speed and tension of the negative electrode entering the negative electrode splicing process.

[0130] Furthermore, in some embodiments of this application, the average unwinding speed of the positive electrode unwinding process is lower than the travel speed of the positive electrode segment; the average unwinding speed of the negative electrode unwinding process is lower than the travel speed of the negative electrode segment. The unwinding speed of the first diaphragm unwinding process and the second diaphragm unwinding process is equal to the travel speed of the positive electrode segment / negative electrode segment.

[0131] Furthermore, in some embodiments of this application, the continuous composite process includes a first composite process, a second composite process, and a third composite process; the first composite process includes composited positive electrode strip with the first separator unwound in the first separator unwinding process; the second composite process includes composited negative electrode strip with the second separator unwound in the second separator unwinding process; and the third composite process includes composited the connecting strip / separator on the positive electrode strip with the connecting strip / separator on the negative electrode strip.

[0132] Furthermore, in some embodiments of this application, the first composite process, the second composite process, and the third composite process are all electrostatic composite processes.

[0133] In some embodiments, the battery cell winding process provided by this solution includes: S111: The positive electrode sheet is unwound downstream using the positive electrode sheet unwinding mechanism; S112: Positive electrode sheet adjustment process: Based on the changes in electrode sheet tension and travel speed before and after the positive electrode sheet in the cutting mechanism is cut, actively adjust the feeding speed and tension of the positive electrode sheet entering the positive electrode sheet continuation process. S211: The positive electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the positive electrode sheet to form a positive electrode segment. The cut positive electrode segment continues to move at a constant speed to approach the connecting mechanism. S212 increases the roller feeding speed of the positive electrode segment and decreases the linear feeding speed of the positive electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the positive electrode segment, until the linear feeding speed of the positive electrode segment is 0, and the positive electrode segment is fed into the tape receiving mechanism. S213: First decelerate the cut positive electrode sheet and then accelerate it to increase the distance between it and the positive electrode segment to the preset distance, and make the travel speed of the head of the cut positive electrode sheet the same as the travel speed of the positive electrode segment; repeat steps S211 and S212. S311: Accelerate the composite roller and the connecting strip adsorbed on the composite roller to the roller speed equal to the traveling speed of the positive electrode sheet, and at the same time move the composite roller to press the tail of the previous electrode segment, release the state of the connecting strip being adsorbed, and continue to rotate the composite roller so that the connecting strip is combined at the tail of the previous electrode segment and the head of the next electrode segment. S312: The composite roller is reset to release the positive electrode sheet and the speed is reduced to 0. The positioning transfer roller feeds the next connecting strip into the composite roller and rotates the composite roller and the positioning transfer roller until the head of the connecting strip is in the set initial position, waiting for the next connecting strip composite. S313: Reverse the positioning transfer roller to the position where the tail of the next connecting belt and the first positioning member are expected to be aligned with the flying cutter. The pressure roller presses the connecting belt onto the positioning transfer roller, and the feeding device feeds a piece to the positioning transfer roller. The positioning transfer roller is rotated until the feeding length of the connecting material is equal to the required length of the connecting belt. The connecting material is cut by the flying cutter to form a fixed-length connecting belt, waiting for the next connecting belt to be fed into the composite roller. The unwinding and splicing processes of the positive electrode sheet and the unwinding and splicing processes of the negative electrode sheet are carried out in parallel and simultaneously. The negative electrode splicing process includes: S121: The negative electrode sheet is unwound downstream using the negative electrode sheet unwinding mechanism; S122: Negative electrode sheet adjustment process: Based on the changes in electrode tension and travel speed before and after the negative electrode sheet in the cutting mechanism is cut, actively adjust the feeding speed and tension of the negative electrode sheet entering the negative electrode sheet continuation process. S221: The negative electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the negative electrode sheet to form a negative electrode segment. The cut negative electrode segment continues to move at a constant speed to approach the tape-connecting mechanism. S222: Increase the roller feeding speed of the negative electrode segment and decrease the linear feeding speed of the negative electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the negative electrode segment, until the linear feeding speed of the negative electrode segment is 0, and the negative electrode segment is fed into the tape receiving mechanism. S223: First decelerate the cut negative electrode sheet and then accelerate it to increase the distance between it and the negative electrode segment to the preset distance, and make the travel speed of the head of the cut negative electrode sheet the same as the travel speed of the negative electrode segment; repeat steps S221 and S222. S321: Accelerate the composite roller and the connecting strip adsorbed on the composite roller to the roller speed equal to the traveling speed of the negative electrode sheet, and at the same time move the composite roller to press the tail of the previous electrode segment, release the state of the connecting strip being adsorbed, and continue to rotate the composite roller so that the connecting strip is combined at the tail of the previous electrode segment and the head of the next electrode segment. S322: The composite roller is reset to release the negative electrode sheet and the speed is reduced to 0. The positioning transfer roller feeds the next connecting strip into the composite roller and rotates the composite roller and the positioning transfer roller until the head of the connecting strip is in the set initial position, waiting for the next connecting strip composite. S323: Reverse the positioning transfer roller to the position where the tail of the next connecting belt, the first positioning element, and the flying cutter are expected to be aligned. The pressure roller presses the connecting belt onto the positioning transfer roller. The feeding device feeds a piece to the positioning transfer roller. The positioning transfer roller is rotated until the feeding length of the connecting material is equal to the required length of the connecting belt. The connecting material is cut by the flying cutter to form a fixed-length connecting belt, waiting for the next connecting belt to be fed into the composite roller.

[0134] Simultaneously with the unwinding and splicing of the positive and negative electrode sheets, the first and second diaphragms are unwound; S401: Composite the first separator with the positive electrode material strip, and composite the second separator with the negative electrode material strip; S402: The first separator is combined with the connecting strip on the positive electrode material strip, the connecting strip on the negative electrode material strip with the first separator, and the second separator with the connecting strip on the negative electrode material strip to form a composite structure strip; S501: The composite structure strip is fed into the winding mechanism, where it is cut and wound to form a battery cell.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell winding system, characterized in that, include: The unwinding mechanism includes an electrode unwinding device for providing electrode sheets to a downstream mechanism and a diaphragm unwinding mechanism for providing diaphragms to a downstream mechanism. The splicing subsystem includes a section located downstream of the unwinding mechanism for cutting the electrode sheet into electrode segments and connecting adjacent electrode segments into a continuous electrode sheet strip via a connecting belt. The continuous winding subsystem includes a composite mechanism and a winding needle mechanism located downstream of the splicing subsystem. The composite mechanism is used to combine the connecting strip and the diaphragm to form a composite structure strip. The winding needle mechanism is used to cut and wind the composite structure strip to form a battery cell.

2. The cell winding system according to claim 1, characterized in that, The electrode strip is continuously and uniformly fed into the needle winding mechanism.

3. The cell winding system according to claim 1, characterized in that, The electrode unwinding device includes a positive electrode unwinding device for unwinding positive electrode sheets and a negative electrode unwinding device for unwinding negative electrode sheets. The splicing subsystem includes a first splicing subsystem and a second splicing subsystem. The first splicing subsystem is located downstream of the positive electrode unwinding device, and the second splicing subsystem is located downstream of the negative electrode unwinding device. The composite mechanism includes a first composite device for combining the connecting strip / diaphragm of the first splicing subsystem with the connecting strip / diaphragm of the second splicing subsystem to form a composite structure strip.

4. The cell winding system according to claim 3, characterized in that, The diaphragm unwinding mechanism includes a first diaphragm unwinding mechanism for unwinding the first diaphragm and a second diaphragm unwinding mechanism for unwinding the second diaphragm; The cell winding system further includes a second composite device and a third composite device, which are located upstream of the first composite device. The second composite device is used to composite the first diaphragm unwound by the first diaphragm unwinding mechanism with the positive electrode strip formed by the first connecting subsystem. The third composite device is used to composite the second diaphragm unwound by the second diaphragm unwinding mechanism with the negative electrode strip formed by the second connecting subsystem.

5. The cell winding system according to claim 3 or 4, characterized in that, Both the first and second splicing subsystems include a sheet feeding and adjustment device, an electrode cutting and feeding mechanism, and a tape splicing mechanism; The electrode feeding adjustment device is located downstream of the electrode unwinding device and is used to adjust the feeding speed of the electrode sheets fed into the downstream mechanism. The electrode cutting and feeding mechanism is located downstream of the feeding adjustment device and includes a cutting device and a moving feeding device. The cutting device is used to cut the electrode to form electrode segments. The moving feeding device moves back and forth along the traveling direction of the electrode segments and simultaneously uses roller feeding and linear feeding methods to feed the electrode segments into the downstream mechanism. The connecting belt mechanism is located downstream of the cutting device and is used to connect adjacent pole segments with a spacing between them fed by the moving feeding device via a connecting belt.

6. The cell winding system according to claim 5, characterized in that, The sum of the speed at which the electrode segment is roller-fed and the speed at which it is linearly fed in the electrode cutting and feeding mechanism is equal to the speed at which the electrode segment is fed into the tape receiving mechanism, and the electrode segment travels at a constant speed in the tape receiving mechanism.

7. The cell winding system according to claim 5, characterized in that, The feeding adjustment device includes an adjustment component and a drive roller; The adjustment component is located upstream of the electrode cutting and feeding mechanism and is used to absorb the tension of the electrode in the electrode cutting and feeding mechanism or to provide tension to the electrode in the electrode cutting and feeding mechanism. The active roller is located upstream or downstream of the adjustment assembly and is used to transport the electrode to the electrode cutting and feeding mechanism.

8. The cell winding system according to claim 7, characterized in that, The adjustment assembly includes an adjustment roller and an adjustment driver for driving the adjustment roller to move.

9. The cell winding system according to claim 8, characterized in that, The adjusting roller is located downstream of the driving roller; the adjusting driver is used to drive the adjusting roller to reciprocate in a straight line parallel to the traveling direction of the electrode.

10. The cell winding system according to claim 8, characterized in that, The adjustment assembly also includes a buffer and a moving component disposed between the adjustment roller and the adjustment driver; One end of the buffer is connected to the moving part, and the other end is connected to the adjusting roller; the adjusting driver drives the moving part, the buffer, and the adjusting roller to move back and forth. The electrode plate contacts the side of the adjusting roller away from the buffer.

11. The cell winding system according to any one of claims 5 to 10, characterized in that, The electrode feeding adjustment device further includes a tension detection element; the tension detection element is located between the adjustment roller and the moving electrode feeding device, and is used to detect the tension change of the electrode sheet; The adjustment driver drives the adjustment roller to move according to the change in electrode tension detected by the tension detection element.

12. The cell winding system according to claim 5, characterized in that, The mobile wafer feeding device includes a first wafer feeding device and a second wafer feeding device; The first feeding device is located upstream of the cutting device. The first feeding device reciprocates between the feeding adjustment device and the tape-connecting mechanism to feed the cut electrode sheet into the tape-connecting mechanism according to the spacing between adjacent electrode sheets. The second feeding device is located downstream of the cutting device; the second feeding device reciprocates between the feeding adjustment device and the tape receiving mechanism. The first and second feeding devices are used to feed the cut electrode sheets into the splicing mechanism according to the spacing between adjacent electrode sheets.

13. The cell winding system according to claim 12, characterized in that, The first feeding device includes a first feeding roller for feeding the electrode sheet and a first linear driver for driving the first feeding roller to reciprocate along the traveling direction of the electrode sheet. The second feeding device includes a second feeding roller for feeding the electrode sheet and a second linear driver for driving the second feeding roller to reciprocate along the traveling direction of the electrode sheet.

14. The cell winding system according to claim 13, characterized in that, The first feeding roller includes a first feeding roller A and a first feeding roller B located on both sides of the electrode sheet, and a first roller feed driver for driving the first feeding roller A and / or the first feeding roller B to rotate. The second feeding roller includes a second feeding roller A and a second feeding roller B located on both sides of the electrode sheet, and a second roller driver for driving the second feeding roller A and / or the second feeding roller B to rotate.

15. The cell winding system according to claim 14, characterized in that, The first linear driver drives the first feeding roller to reciprocate along the traveling direction of the electrode sheet; The second linear driver drives the second feeding roller to reciprocate along the traveling direction of the electrode sheet; The feeding speed of the first feeding device is equal to the sum of the moving speed of the first linear drive in the electrode travel direction and the rolling speed of the first feeding roller; The feeding speed of the second feeding device is equal to the sum of the moving speed of the second linear driver in the electrode travel direction and the rolling speed of the second feeding roller.

16. The cell winding system according to claim 12, characterized in that, The first feeding device moves synchronously with the cutting device.

17. The cell winding system according to claim 16, characterized in that, The cutting device and the first feeding device are mounted on the same moving platform; the first linear driver drives the moving platform to reciprocate along the direction of travel of the electrode sheet.

18. The cell winding system according to claim 5, characterized in that, The receiving mechanism includes: The belt feeding device is used to convey the connecting belt to the pole segment; A cutting device is used to cut the connecting strip to form a connecting strip; A positioning and transition device includes a positioning and transition roller and a first positioning element disposed on the positioning and transition roller; the first positioning element is used to position the tail end of the connecting belt; The tape-attaching device includes a composite roller for receiving the connecting tape fed in by the positioning transfer roller and attaching it to the surface of adjacent pole segments.

19. The cell winding system according to claim 18, characterized in that, The flying cutter includes a flying knife, a first driver that drives the flying knife to move, a pressure roller, and a second driver that drives the pressure roller to move closer to or away from the positioning transfer roller; The pressure roller is located upstream of the flying knife.

20. The cell winding system according to claim 19, characterized in that, The first positioning element is a flying cutter groove disposed on the positioning transfer roller, and the flying cutter groove is configured to cooperate with the flying knife.

21. The cell winding system according to claim 19, characterized in that, The positioning adapter also includes a third driver for driving the positioning adapter roller closer to or further away from the composite roller.

22. The cell winding system according to claim 19, characterized in that, The vertical distance between the composite roller and the electrode is less than the vertical distance between the positioning transfer roller and the electrode.

23. The cell winding system according to claim 19, characterized in that, The composite roller, positioning transfer roller, and pressure roller are all vacuum adsorption rollers with several vacuum adsorption holes for external vacuum generators on their outer circumferential surface.

24. The cell winding system according to claim 18, characterized in that, The composite device also includes a fifth driver that drives the composite roller to move closer to or away from the electrode.

25. The cell winding system according to claim 18, characterized in that, The connecting belt mechanism also includes a tension buffer device located upstream of the flying cutter, used to absorb tension in the connecting belt or to provide tension to the connecting belt.

26. The cell winding system according to claim 3, characterized in that, The distance between the first composite device and the cutting point of the composite structure belt and the winding needle is 50mm-100mm.

27. The cell winding system according to claim 26, characterized in that, The first composite device is an electrostatic generator.

28. A battery cell winding process, characterized in that, The battery cell winding system according to any one of claims 1 to 27 is used to wind the battery cell, and the battery cell winding process includes: an unwinding process, an electrode splicing process, and a continuous winding process. The unwinding process includes a synchronous unwinding process for the positive electrode sheet and a synchronous unwinding process for the negative electrode sheet, as well as a synchronous unwinding process for the first diaphragm and a synchronous unwinding process for the second diaphragm. The electrode splicing process includes a positive electrode splicing process and a negative electrode splicing process performed simultaneously. The positive electrode splicing process includes cutting the positive electrode sheet unwound from the positive electrode sheet unwinding process into positive electrode segments while traveling at a constant speed, and connecting the two adjacent positive electrode segments into a continuous positive electrode strip using a connecting belt fed at the same speed after the distance between them is increased to the target distance. The negative electrode splicing process includes cutting the negative electrode sheet unwound from the negative electrode sheet unwinding process into negative electrode segments while traveling at a constant speed, and connecting the two adjacent negative electrode segments into a continuous negative electrode strip using a connecting belt fed at the same speed after the distance between them is increased to the target distance. The continuous winding process includes a continuous composite process and a winding process; the continuous composite process includes combining the positive electrode strip, the first separator, the negative electrode strip, and the second separator into a composite structure layer; the winding process includes feeding the composite structure layer into a winding machine for winding, cutting, and starting to wind the next cell.

29. A cell winding process according to claim 28, characterized in that, The positive and negative electrode segments formed by the cutting process travel at a constant speed before entering the winding machine.

30. The cell winding process according to claim 28, characterized in that, The travel speed of the positive and negative electrode segments formed by the cutting process before entering the winding machine is not less than 2000 mm / s.

31. The cell winding process according to claim 28, characterized in that, The positive electrode splicing process includes: S211: The positive electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the positive electrode sheet to form a positive electrode segment. The cut positive electrode segment continues to move at a constant speed to approach the connecting mechanism. S212 increases the roller feeding speed of the positive electrode segment and decreases the linear feeding speed of the positive electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the positive electrode segment, until the linear feeding speed of the positive electrode segment is 0, and the positive electrode segment is fed into the tape receiving mechanism. S213: First decelerate the cut positive electrode sheet and then accelerate it to increase the distance between it and the positive electrode segment to the preset distance, and make the travel speed of the head of the cut positive electrode sheet the same as the travel speed of the positive electrode segment; repeat steps S211 and S212. The positive electrode splicing process and the negative electrode splicing process are performed in parallel and simultaneously; The negative electrode splicing process includes: S221: The negative electrode sheet is fed into the cutting mechanism at a constant speed according to the preset length of the electrode segment. The cutting mechanism is used to cut the negative electrode sheet to form a negative electrode segment. The cut negative electrode segment continues to move at a constant speed to approach the tape-connecting mechanism. S222 increases the roller feeding speed of the negative electrode segment and decreases the linear feeding speed of the negative electrode segment so that the sum of the roller feeding speed and the linear feeding speed is equal to the uniform feeding speed of the negative electrode segment, until the linear feeding speed of the negative electrode segment is 0, and the negative electrode segment is fed into the tape receiving mechanism. S223: First slow down the cut negative electrode sheet and then accelerate it to increase the distance between it and the negative electrode segment to the preset distance, and make the travel speed of the head of the cut negative electrode sheet the same as the travel speed of the negative electrode segment; repeat steps S221 and S222.

32. The cell winding process according to claim 31, characterized in that, Upstream of the positive electrode sheet splicing process and the negative electrode sheet splicing process, there are also positive electrode sheet adjustment processes and negative electrode sheet adjustment processes, respectively. The positive electrode adjustment process is used to actively adjust the feeding speed and tension of the positive electrode entering the positive electrode splicing process; The negative electrode adjustment process is used to actively adjust the feeding speed and tension of the negative electrode entering the negative electrode splicing process.

33. The cell winding process according to claim 32, characterized in that, The average unwinding speed of the positive electrode unwinding process is lower than the travel speed of the positive electrode segment; the average unwinding speed of the negative electrode unwinding process is lower than the travel speed of the negative electrode segment. The unwinding speed of the first diaphragm unwinding process and the second diaphragm unwinding process is equal to the travel speed of the positive electrode segment / negative electrode segment.

34. The cell winding process according to claim 28, characterized in that, The continuous composite process includes a first composite process, a second composite process, and a third composite process; the first composite process includes composited positive electrode strip with the first separator unwound in the first separator unwinding process; the second composite process includes composited negative electrode strip with the second separator unwound in the second separator unwinding process; the third composite process includes composited the connecting strip / separator on the positive electrode strip with the connecting strip / separator on the negative electrode strip.

35. The cell winding process according to claim 34, characterized in that, The first composite process, the second composite process, and the third composite process are all electrostatic composite processes.

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