Continuous sheet-feeding and winding mechanism and winding process thereof

Abstract

The present application relates to the technical field of battery cell winding. Provided in the embodiments of the present application are a continuous sheet-feeding and winding mechanism and a winding process thereof. The winding process provided in the embodiments of the present application comprises a first bonding process, a second bonding process and a winding and cutting process, wherein the first bonding process comprises a positive electrode sheet and separator bonding process and a negative electrode sheet and separator bonding process that are performed synchronously; the second bonding process comprises bonding a positive composite layer and a negative composite layer to form a combined composite layer; and the winding and cutting process comprises feeding the combined composite layer into a winding machine at a running speed of not less than 600 mm / s for winding, and cutting same and starting to wind the next battery cell. Further provided in the present application is a continuous sheet-feeding and winding mechanism. The winding process provided in the present application can realize continuous feeding and winding at a high speed of 600 mm / s or more.

Description

A continuous film feeding and winding mechanism and its winding process

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 2024101691373, filed with the Chinese Patent Office on February 6, 2024, entitled “A continuous sheet feeding and winding mechanism and its winding process”; the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of battery winding, and in particular to a continuous sheet feeding and winding mechanism and a winding process thereof. Background Art

[0004] One of the main structures of existing lithium-ion power battery core packs is the core structure. The battery core of this structure is usually produced by a winding process. Compared with the battery core pack of the stacked core structure, the production efficiency of this process is higher and the tension control of the electrode and diaphragm is better. In the traditional winding process, when the electrode is fed and the electrode and diaphragm are fed into the winding machine, it is usually necessary to slow down or stop the machine to feed the material in order to achieve the correction and alignment of the electrode and diaphragm, but this is not conducive to improving the efficiency of the winding process. Therefore, in order to achieve continuous winding, the existing technology proposes to combine the electrode and the diaphragm before winding. However, due to the long length of the electrode and diaphragm of the core, the combination of the electrode and the diaphragm is difficult and costly, and it is not conducive to the correction and alignment of the electrode and the diaphragm, so it is difficult to be truly applicable to production.

[0005] Application Contents

[0006] One of the purposes of the embodiments of the present application is to provide a winding process for continuous sheet feeding and winding in which sheet feeding and winding are separated and which has high continuous sheet feeding speed and high winding efficiency.

[0007] Another object of the embodiments of the present application is to provide a continuous film feeding and winding mechanism.

[0008] In a first aspect, the present application discloses a continuous sheet feeding and winding process, comprising a first combining process, a second combining process, and a winding and cutting process;

[0009] The first bonding process includes a positive electrode sheet-separator bonding process and a negative electrode sheet-separator bonding process performed simultaneously; the positive electrode sheet-separator bonding process includes bonding the head of the positive electrode sheet and the first separator to form a positive electrode composite layer; the negative electrode sheet-separator bonding process includes bonding the head of the negative electrode sheet and the second separator to form a negative electrode composite layer; wherein the positive electrode sheet is formed by cutting the positive electrode sheet; and the negative electrode sheet is formed by cutting the negative electrode sheet;

[0010] The second combining step includes: combining the positive electrode composite layer and the negative electrode composite layer to form a combined composite layer;

[0011] The winding and cutting process includes: feeding the combined composite layer into a winding machine for winding, cutting, and winding the next battery cell.

[0012] Furthermore, in some embodiments of the present application, in the winding and cutting process, the combined composite layer is fed into a winding machine for winding at a speed of not less than 600 mm / s.

[0013] Furthermore, in some embodiments of the present application, the combined length of each positive electrode plate and the first separator is no more than 1.5 times the outer circumference of the formed battery cell.

[0014] Furthermore, in some embodiments of the present application, the combined length of each negative electrode plate and the second separator is no more than 1.5 times the outer circumference of the formed battery cell.

[0015] Furthermore, in some embodiments of the present application, the combined length of the positive electrode composite layer and the negative electrode composite layer is no greater than the outer circumference of the formed battery cell.

[0016] Furthermore, in some embodiments of the present application, the area of ​​each positive electrode sheet combined with the first separator does not exceed the vertical projection area of ​​the obtained battery cell on the plane in the width direction;

[0017] The area where each negative electrode plate is combined with the second separator does not exceed the vertical projection area of ​​the obtained battery cell on the plane where the width direction is located.

[0018] Furthermore, in some embodiments of the present application, the combined composite layer is a composite structure formed by stacking a positive electrode sheet, a first separator, a negative electrode sheet, and a second separator in sequence;

[0019] There is a first spacing between adjacent positive electrode sheets; there is a second spacing between adjacent negative electrode sheets; and there is an overlapping area between the projections of the first spacing and the second spacing in a direction perpendicular to the first diaphragm / the second diaphragm;

[0020] The positive electrode composite layer and the negative electrode composite layer are partially combined in the overlapping area, and a gap exists between the combined area of ​​the positive electrode composite layer and the negative electrode composite layer and the tail of the negative electrode sheet.

[0021] Furthermore, in some embodiments of the present application, the bonding area of ​​the positive electrode composite layer and the negative electrode composite layer includes a first area and a second area, the first area is a part of the overlapping area; the second area includes the area corresponding to the bonding part of the positive electrode plate and the first diaphragm; the first area and the second area are connected into one piece.

[0022] Furthermore, in some embodiments of the present application, the positive electrode composite layer and the negative electrode composite layer corresponding to the tail of the positive electrode sheet and the tail of the negative electrode sheet are not bonded to each other.

[0023] Furthermore, in some embodiments of the present application, the positive electrode composite layer and the negative electrode composite layer are electrostatically bonded; and / or

[0024] The head of the positive electrode plate is bonded or glued to the first separator by hot pressing, and the head of the negative electrode plate is bonded or glued to the second separator by hot pressing.

[0025] In a second aspect, the present application further provides a continuous film feeding and winding mechanism, comprising:

[0026] An unwinding device, comprising a positive electrode unwinding and cutting device, a negative electrode unwinding and cutting device, a first diaphragm unwinding device and a second diaphragm unwinding device;

[0027] a combining device, disposed downstream of the unwinding device, configured to combine the head of the positive electrode sheet with the first separator to form a positive electrode composite layer, combine the head of the negative electrode sheet with the second separator to form a negative electrode composite layer, and combine the positive electrode composite layer with the negative electrode composite layer to form a combined composite layer; wherein the positive electrode sheet is formed by cutting the positive electrode sheet; and the negative electrode sheet is formed by cutting the negative electrode sheet;

[0028] a winding device, disposed downstream of the combining device, configured to cut the separator and wind it to form a battery cell;

[0029] The head portion is the portion close to the moving direction of the positive electrode sheet / negative electrode sheet when the positive electrode sheet / negative electrode sheet is combined with the first diaphragm / second diaphragm.

[0030] Furthermore, in some embodiments of the present application, the combining device includes a first combining device, a second combining device, and a third combining device, wherein the first combining device is configured to combine the head of the positive electrode sheet with the first separator to form a positive electrode composite layer;

[0031] The second combining device is configured to combine the head of the negative electrode sheet with the second separator to form a negative electrode composite layer; wherein the positive electrode sheet is formed by cutting the positive electrode sheet; and the negative electrode sheet is formed by cutting the negative electrode sheet;

[0032] The third combining device is located downstream of the first combining device and the second combining device, and is configured to combine the positive electrode composite layer and the negative electrode composite layer to form a combined composite layer.

[0033] Further, in some embodiments of the present application, the first bonding device is a heat-compression bonding device or an adhesive bonding device;

[0034] The second bonding device is a heat-pressing bonding device or an adhesive bonding device;

[0035] The third bonding device is a hot pressing bonding device or an electrostatic bonding device.

[0036] Further, in some embodiments of the present application, the first combining device includes a first combining assembly, a first driver, and a first meter; the first combining assembly includes a second combining member and a first combining member, and a gap configured to allow the positive electrode sheet and the first diaphragm to pass between the first combining member and the second combining member; the first driver is connected to the first combining member and drives the first combining member to contact / move away from the first diaphragm, and the gap between the first combining member and the second combining member is no greater than the sum of the thicknesses of the positive electrode sheet and the first diaphragm; the first meter is configured to collect the time when the first combining assembly contacts / move away from the first diaphragm;

[0037] The second coupling device includes a second coupling assembly, a third driver, and a second meter; the second coupling assembly includes a fourth coupling member and a third coupling member, a gap configured to allow the negative electrode sheet and the second diaphragm to pass between the fourth coupling member and the third coupling member; the third driver is connected to the third coupling member and drives the third coupling member to contact or move away from the second diaphragm, and the gap between the third coupling member and the fourth coupling member is no greater than the sum of the thicknesses of the negative electrode sheet and the second diaphragm; the second meter is configured to collect the time when the second coupling assembly contacts or moves away from the second diaphragm;

[0038] The third combining device includes a fifth combining member, a sixth combining member, a fifth driver, a sixth driver and a third meter. A gap is provided between the fifth combining member and the sixth combining member so that the positive electrode composite layer and the negative electrode composite layer pass through. The fifth driver is connected to the fifth combining member and drives the fifth combining member to contact / move away from the first diaphragm / the cathode sheet and / or the sixth driver is connected to the sixth combining member and drives the sixth combining member to contact / move away from the second diaphragm, and makes the first diaphragm / the cathode sheet contact the second diaphragm. The third meter is configured to collect the time when the fifth combining member contacts / moves away from the first diaphragm / cathode sheet or the sixth combining member contacts / moves away from the second diaphragm.

[0039] Further, in some embodiments of the present application, the first bonding device includes a first heating component, the first heating component being disposed on the first bonding component and configured to heat the first bonding component;

[0040] The second bonding device includes a second heating assembly disposed on the second bonding assembly and configured to heat the second bonding assembly;

[0041] The third combining device includes a third heating assembly and a fourth heating device, and the third heating assembly and the fourth heating device are respectively disposed on the fifth combining piece and the sixth combining piece and are configured to heat the fifth combining piece and the sixth combining piece.

[0042] Furthermore, in some embodiments of the present application, the first combining device further includes a seventh driver, the seventh driver driving the first combining assembly to move toward the movement direction of the positive electrode sheet, and the movement speed of the first combining assembly is equal to the movement speed of the positive electrode sheet;

[0043] The second combining device further includes an eighth driver, the eighth driver driving the second combining assembly to move toward the movement direction of the negative electrode sheet, and the movement speed of the second combining assembly is equal to the movement speed of the negative electrode sheet;

[0044] The third combining device includes a ninth driver, which drives the fifth and sixth combining members to move in the direction of movement of the combined composite layer, and the moving speed of the fifth and sixth combining members is equal to the moving speed of the combined composite layer.

[0045] Furthermore, in some embodiments of the present application, a controller is further included, and the controller is communicatively connected with the first combining device, the second combining device and the third combining device.

[0046] Furthermore, in some embodiments of the present application, the positive electrode unwinding and cutting device includes a positive electrode unwinding assembly, a first buffer assembly, a first pinching sheet assembly, and a first cutting assembly arranged in sequence; the positive electrode unwinding assembly unwinds the positive electrode sheet to the first cutting assembly, and the first cutting assembly cuts the positive electrode sheet into positive electrode sheets; the first buffer assembly is located between the positive electrode unwinding assembly and the first cutting assembly, and is configured to increase the distance between two adjacent positive electrode sheets; the first pinching sheet assembly is located between the first buffer assembly and the first cutting assembly, and is configured to pinch and feed the positive electrode sheet to the first cutting assembly;

[0047] The negative electrode unwinding and cutting device includes a negative electrode unwinding assembly, a second buffer assembly, a second pinching sheet assembly and a second cutting assembly; the negative electrode unwinding assembly unwinds the negative electrode sheet to the second cutting assembly, and the second cutting assembly cuts the negative electrode sheet into negative electrode sheets; the second buffer assembly is located between the negative electrode unwinding assembly and the second cutting assembly, and is configured to increase the distance between two adjacent negative electrode sheets; the second pinching sheet assembly is located between the second buffer assembly and the second cutting assembly, and is configured to pinch and feed the negative electrode sheet to the second cutting assembly.

[0048] Furthermore, in some embodiments of the present application, a first deviation-correcting component is further provided between the first buffer component and the first cutting component;

[0049] A second deviation-correcting assembly is further provided between the second buffer assembly and the second cutting assembly.

[0050] Furthermore, in some embodiments of the present application, the first diaphragm unwinding device and the second diaphragm unwinding device unwind synchronously and continuously at a uniform speed;

[0051] The unwinding speeds of the first diaphragm unwinding device and the second diaphragm unwinding device are equal to the forward speeds of the negative electrode composite layer and the positive electrode composite layer in the combining device.

[0052] Furthermore, in some embodiments of the present application, the unwinding speed of the positive electrode sheet, the unwinding speed of the negative electrode sheet, the unwinding speed of the first separator, and the unwinding speed of the second separator are all not less than 600 mm / s.

[0053] Beneficial effects of this application:

[0054] The embodiment of the present application provides a winding process for continuous sheet feeding and winding, which adds a first combining process and a second combining process between the unwinding process and the winding process, combines the positive electrode sheet and the first diaphragm at the head of the positive electrode sheet, and the negative electrode sheet and the second diaphragm at the head of the negative electrode sheet, and then directly combines the first diaphragm and the second diaphragm in the positive electrode combination composite layer and the negative electrode combination composite layer formed by combining respectively, so as to obtain a combined composite layer in which only the head of the positive electrode sheet is combined with the first diaphragm, only the head of the negative electrode sheet is combined with the second diaphragm, and the first diaphragm and the second diaphragm can be directly combined between the previous negative electrode sheet and the next negative electrode sheet, so that the heads of the positive electrode sheet and the negative electrode sheet are combined with the first diaphragm and the second diaphragm into a whole, while the tails of the positive electrode sheet and the negative electrode sheet still retain freedom, so that the positive electrode sheet and the negative electrode sheet can be combined into a whole. The pole sheet, the first diaphragm, the negative pole sheet and the second diaphragm can be wound at a uniform speed at the same time, without the need to set up a separate winding device for the positive pole sheet and the negative pole sheet. At the same time, it can also provide freedom for correcting the deviation of the positive pole sheet, the first diaphragm, the negative pole sheet and the second diaphragm, thereby realizing the correction of the positive pole sheet and the negative pole sheet and adjusting the tension during the winding process, reducing the tension unevenness and wrinkles. Moreover, since it only combines the head of the positive pole sheet with the first diaphragm and the head of the negative pole sheet with the second diaphragm, it can also reduce the time and cost required for the combination of the positive pole sheet and the first diaphragm, and the time and cost required for the combination of the negative pole sheet and the second diaphragm, thereby reducing the difficulty of combining the pole sheet and the diaphragm. Moreover, it can also increase the winding speed of the battery cell, so that it can achieve continuous winding at a feeding speed of more than 600 mm / s or even more than 2000 mm / s. In addition, since the head of the positive electrode sheet is combined with the first diaphragm and the head of the negative electrode sheet is combined with the second diaphragm, the defects of the positive electrode sheet and the negative electrode sheet swinging their heads and tails during the feeding, winding and cutting processes, as well as the defects of the positive electrode sheet and the negative electrode sheet heads hanging in the air after cutting can be avoided.

[0055] The embodiment of the present application also provides a continuous sheet feeding and winding mechanism, in which a combining device is provided between the unwinding and cutting device and the winding device, and the combining device is configured to combine the positive electrode sheet with the first diaphragm, and the negative electrode sheet with the second diaphragm, and then combine the first diaphragm and the second diaphragm in the positive electrode composite layer and the negative electrode combining layer, so that the positive electrode sheet and the negative electrode sheet can be fed in the winding process along with the first diaphragm and the second diaphragm, thereby realizing the simultaneous and uniform feeding of the negative electrode sheet, the positive electrode sheet, the first diaphragm and the second diaphragm, without the need to slow down, start and stop, or adjust the feeding speed of the negative electrode sheet, the positive electrode sheet, the first diaphragm and the second diaphragm, thereby realizing continuous, uniform and high-speed feeding, and its combining device only combines the positive electrode sheet with the first diaphragm, the negative electrode sheet with the second diaphragm, and the first diaphragm and the second diaphragm in a specific area, and the time required for the combination is short, which does not affect the continuous movement of the positive electrode sheet, the negative electrode sheet, the first diaphragm and the second diaphragm and the combined composite layer formed therebetween, and the combination difficulty is low, and it is easy to promote and use. The continuous sheet feeding and winding mechanism provided in the embodiment of the present application can achieve continuous sheet feeding and winding of the positive electrode sheet, the negative electrode sheet, the first diaphragm and the second diaphragm at a speed of more than 600 mm / s, and can even achieve continuous sheet feeding and winding at more than 2000 mm / s. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] FIG1 is a schematic diagram of a continuous sheet feeding and winding process provided in some embodiments of the present application;

[0057] FIG2 is a partial enlarged view of FIG1 ;

[0058] FIG3 is a schematic structural diagram of a combined device for a continuous sheet feeding and winding process provided by some embodiments of the present application;

[0059] Among them, A-first spacing, B-second spacing, C-overlapping area, 1-positive electrode unwinding assembly, 2-first buffer assembly, 3-first deviation correction assembly, 4-first pinching sheet assembly, 5-first cutting assembly, 6-first combining device, 61-positive electrode sheet, 62-negative electrode sheet, 611-first combining roller, 612-first rotating motor, 613-first driver, 614-first screw assembly, 621-second combining roller, 622-second rotating motor, 623- Second drive, 624-second screw assembly, 7-first diaphragm unwinding device, 71-first diaphragm, 72-second diaphragm, 8-negative electrode unwinding assembly, 9-second buffer assembly, 10-second correction assembly, 11-second diaphragm unwinding device, 12-second clamping sheet assembly, 13-second cutting assembly, 14-second combining device, 15-first electrostatic generator, 16-second electrostatic generator, 17-third combining device, 18-winding device, 19-cutting device. DETAILED DESCRIPTION

[0060] In order to better explain the present application, the present application is described in detail with reference to the implementation methods of the present application, and the main content of the present application is further clarified in combination with specific examples, but the content of the present application is not limited to the following examples.

[0061] In the description of this application, it should be understood that the terms "thickness," "upper," "lower," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the term "plurality" means two or more, unless otherwise specifically defined.

[0062] The disclosure below provides many different embodiments or examples for realizing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art will appreciate the application of other processes and / or the use of other materials.

[0063] The present application discloses a continuous sheet feeding and winding process, referring to FIG1 , which includes a first combining process, a second combining process, and a winding and cutting process;

[0064] The first bonding process includes a positive electrode sheet-separator bonding process and a negative electrode sheet-separator bonding process performed simultaneously; the positive electrode sheet-separator bonding process includes bonding the head of the positive electrode sheet and the first separator to form a positive electrode composite layer; the negative electrode sheet-separator bonding process includes bonding the head of the negative electrode sheet and the second separator to form a negative electrode composite layer; wherein the positive electrode sheet is formed by cutting the positive electrode sheet; and the negative electrode sheet is formed by cutting the negative electrode sheet;

[0065] The second combining step includes: feeding the combined composite layer into a winding machine for winding, cutting, and winding the next battery cell.

[0066] Preferably, in the winding and cutting process, the combined composite layer is fed into a winding machine for winding at a speed of not less than 600 mm / s.

[0067] More preferably, in the winding and cutting process, the combined composite layer is fed into the winding machine for winding at a speed of not less than 1000 mm / s; still more preferably, in the winding and cutting process, the combined composite layer is fed into the winding machine for winding at a speed of not less than 2000 mm / s.

[0068] It should be noted that the continuous sheet feeding and winding process provided in the present application also includes a positive electrode sheet unwinding-cutting process, a negative electrode sheet unwinding-cutting process, a first diaphragm unwinding process and a second diaphragm unwinding process before the first combining process; the above four processes are carried out simultaneously, so that the positive electrode sheet, negative electrode sheet and the continuous first diaphragm and second diaphragm formed by cutting enter the first combining process at the same time.

[0069] The unwinding and cutting process of the positive electrode sheet includes: unwinding the positive electrode sheet using a positive electrode unwinding device and cutting the positive electrode sheet into a predetermined length; during the cutting process of the positive electrode sheet, a buffer device is used upstream of the cutting process to increase a first spacing of a predetermined length between the positive electrode sheets;

[0070] The unwinding and cutting process of the negative electrode sheet includes: unwinding the negative electrode sheet using a negative electrode unwinding device and cutting the negative electrode sheet into a predetermined length; during the cutting process of the negative electrode sheet, a buffer device is used upstream of the cutting process to increase a second spacing of a predetermined length between the negative electrode sheets;

[0071] The unwinding and cutting process of the positive electrode sheet also includes positive electrode sheet correction. After the positive electrode sheet passes through the buffer device, it is first corrected before entering the cutting process. The unwinding and cutting process of the negative electrode sheet also includes negative electrode sheet correction. After the negative electrode sheet passes through the buffer device, it is first corrected before entering the cutting process to align the cut positive electrode sheet with the first separator and the cut negative electrode sheet with the second separator.

[0072] In the present application, the unwinding speed of the positive electrode sheet, the unwinding speed of the negative electrode sheet, the unwinding speed of the first diaphragm, and the unwinding speed of the second diaphragm can all be no less than 600 mm / s, and the first diaphragm and the second diaphragm are continuously unwound at a uniform speed; the positive electrode sheet and the negative electrode sheet are also continuously unwound at a uniform speed, but their unwinding speeds are slightly lower than the unwinding speeds of the first diaphragm and the second diaphragm, and the difference between the unwinding speeds of the first diaphragm and the second diaphragm and the unwinding speeds of the positive electrode sheet and the negative electrode sheet can be adjusted according to the length of the first spacing between adjacent positive electrode sheets and the second spacing between adjacent negative electrode sheets. And because the head of the positive electrode sheet is combined with the first diaphragm, and the head of the negative electrode sheet is combined with the second diaphragm, the positive electrode sheet and the first diaphragm, and the negative electrode sheet and the second diaphragm can be pulled forward synchronously, so that the winding speed and the feeding speed can be further improved. The unwinding speed of the positive electrode sheet, the unwinding speed of the negative electrode sheet, the unwinding speed of the first diaphragm, and the unwinding speed of the second diaphragm can all be increased to more than 1000 mm / s, and can even be increased to more than 2000 mm / s, and continuous feeding and winding can still be achieved.

[0073] In addition, the remaining process parameters of the unwinding-cutting process of the positive electrode sheet, the unwinding-cutting process of the negative electrode sheet, the unwinding process of the first diaphragm and the unwinding process of the second diaphragm are all conventional processes in the prior art, so they will not be described in detail in this application.

[0074] In some embodiments, the combined length of each positive electrode sheet and the first separator is no greater than 1.5 times the outer circumference of the formed battery cell; the combined length of each negative electrode sheet and the second separator is no greater than 1.5 times the outer circumference of the formed battery cell. The combined length of the positive electrode sheet and the first diaphragm should not be too long or too short, so as to avoid the difficulty of combining due to the long combined length, the long time required for combining, which makes it difficult to actually use in production, and the significant impact on the running speed of the positive electrode sheet and the first diaphragm, which makes it difficult to significantly increase the running speed of the positive electrode sheet and the first diaphragm. In addition, if the combined length of the positive electrode sheet and the first diaphragm is too long, the freedom of the tail end of the positive electrode sheet will be greatly restricted, and the thickness cannot be adjusted for deviation, and the tension cannot be freely adjusted during the winding process, which is prone to wrinkles and affects the performance of the battery cell. In addition, if the combined length of the positive electrode sheet and the first diaphragm is too short, it is easy to cause insufficient bonding between the positive electrode sheet and the first diaphragm, and separation is easy to occur during the process of moving, making it difficult to achieve the effects of combining, moving synchronously, and the head not being suspended in the air and not shaking the head. Similarly, the combined length of the negative electrode sheet and the second diaphragm should not be too long or too short.

[0075] Preferably, the combined length of each positive electrode plate and the first separator is no greater than the width of one battery cell; the combined length of each negative electrode plate and the second separator is no greater than the width of two battery cells, and more preferably no greater than the width of the formed battery cell.

[0076] In some embodiments, the combined length of the positive electrode composite layer and the negative electrode composite layer is no greater than the outer circumference of the formed battery cell.

[0077] In some embodiments, the area where each positive electrode sheet is combined with the first diaphragm does not exceed the vertical projection area of ​​the desired battery cell on the plane in the width direction; the area where each negative electrode sheet is combined with the second diaphragm does not exceed the vertical projection area of ​​the desired battery cell on the plane in the width direction, so as to ensure that the positive electrode sheet and the negative electrode sheet and the first diaphragm and the second diaphragm combined therewith move synchronously, and the heads do not hang in the air or swing after winding and cutting; at the same time, the tail ends of the positive electrode sheet and the negative electrode sheet are kept free so that they can be corrected and adjusted in tension to avoid wrinkles.

[0078] In some embodiments, the combined composite layer is a composite structure formed by stacking a positive electrode sheet, a first diaphragm, a negative electrode sheet, and a second diaphragm in sequence; there is a first spacing between adjacent positive electrode sheets; there is a second spacing between adjacent negative electrode sheets; and there is an overlapping area in the projections of the first spacing and the second spacing in the direction perpendicular to the first diaphragm / second diaphragm; the positive composite layer and the negative composite layer are partially combined in the overlapping area, and there is a gap between the combined area of ​​the positive composite layer and the negative composite layer and the tail of the negative electrode sheet.

[0079] It should be noted that the overlapping area C of the projections of the first spacing A and the second spacing B in the direction perpendicular to the first diaphragm / the second diaphragm is shown in Figure 2. In this application, "the positive electrode composite layer and the negative electrode composite layer are partially combined in the overlapping area" should be understood as: the bonding area of ​​the positive electrode composite layer and the negative electrode composite layer includes a partial overlapping area, that is, the projection of the bonding area of ​​the positive electrode composite layer and the negative electrode composite layer in the direction perpendicular to the first diaphragm / the second diaphragm partially overlaps with the projection of the first spacing A and the second spacing B in the direction perpendicular to the first diaphragm / the second diaphragm.

[0080] In the present application, the first separator 71 and the second separator 72 are directly bonded, and a certain gap is provided between the bonding area of ​​the first separator 71 and the second separator 72 and the tail ends of the positive electrode sheet 61 and the negative electrode sheet 62, so that the tail ends of the positive electrode sheet 61 and the negative electrode sheet 62 remain free ends. That is, the positive electrode composite layer and the negative electrode composite layer corresponding to the tail ends of the positive electrode sheet and the negative electrode sheet are not bonded. The length of this gap can be set as required to ensure that the tail ends of the positive electrode sheet 61 and the negative electrode sheet 62 remain free ends.

[0081] During the cutting process, the composite layer is severed at the junction where the first and second separators are directly bonded, separating the front and rear wound battery cells. Because the first and second separators are bonded together, the head of the positive electrode sheet is bonded to the first separator, and the head of the negative electrode sheet is bonded to the second separator. Therefore, after cutting, the positive electrode sheet, the first separator, the heads of the negative electrode sheet, and the second separator can actually be considered as a whole. The positive and negative electrode sheets will not be suspended in the air, nor will they swing off. Furthermore, because the first and second separators are bonded together, after cutting, the first and second separators of the wound core can be considered as a whole, reducing the occurrence of swinging off.

[0082] In some embodiments, the bonding area of ​​the positive electrode composite layer and the negative electrode composite layer includes a first area and a second area, the first area is a part of the overlapping area; the second area includes the area corresponding to the bonding portion of the positive electrode sheet and the first diaphragm; the first area and the second area are connected into one piece, as shown in Figure 2, to improve the bonding strength and integrity of the head of the positive electrode sheet, the first diaphragm, the head of the negative electrode sheet and the second diaphragm, so that they can be pulled and moved as a whole.

[0083] In some embodiments, the positive electrode composite layer and the negative electrode composite layer are electrostatically bonded; the head of the positive electrode plate and the first separator are bonded or glued by hot pressing, and the head of the negative electrode plate and the second separator are bonded or glued by hot pressing.

[0084] The present application also provides a continuous sheet feeding and winding mechanism that can use the above-mentioned continuous sheet feeding and winding process, including an unwinding device, a combining device and a winding device 18;

[0085] The unwinding device includes a positive electrode unwinding and cutting device, a negative electrode unwinding and cutting device, a first diaphragm unwinding device and a second diaphragm unwinding device; the positive electrode unwinding and cutting device is configured to unwind the positive electrode sheet and cut the positive electrode sheet into a positive electrode sheet of a desired length; the negative electrode unwinding and cutting device is configured to unwind the negative electrode sheet and cut the negative electrode sheet into a negative electrode sheet of a desired length; the first diaphragm unwinding device is configured to unwind the first diaphragm, and the second diaphragm unwinding device is configured to unwind the second diaphragm;

[0086] Among them, the positive electrode unwinding and cutting device can be the following structure: it includes a positive electrode unwinding component 1, a first buffer component 2, a first clamping sheet component 4 and a first cutting component 5 arranged in sequence; the positive electrode unwinding component unwinds the positive electrode sheet to the first cutting component, and the first cutting component cuts the positive electrode sheet to form a positive electrode sheet; the first buffer component is located between the positive electrode unwinding component and the first cutting component, and is configured to widen the distance between two adjacent positive electrode sheets; the first clamping sheet component is located between the first buffer component and the first cutting component, and is configured to clamp the positive electrode sheet to the first cutting component.

[0087] The negative electrode unwinding and cutting device can have the following structure: the negative electrode unwinding and cutting device includes a negative electrode unwinding assembly 8, a second buffer assembly 9, a second pinching sheet assembly 12, and a second cutting assembly 13; the negative electrode unwinding assembly unwinds the negative electrode sheet to the second cutting assembly, and the second cutting assembly cuts the negative electrode sheet into negative electrode sheets; the second buffer assembly is located between the negative electrode unwinding assembly and the second cutting assembly, and is configured to increase the distance between two adjacent negative electrode sheets; the second pinching sheet assembly is located between the second buffer assembly and the second cutting assembly, and is configured to pinch the negative electrode sheet to the second cutting assembly. The positive electrode unwinding assembly, the first buffer assembly, the first pinching sheet assembly, the first cutting assembly, the negative electrode unwinding assembly, the second buffer assembly, the second pinching sheet assembly, the second cutting assembly, the first diaphragm unwinding device 7, the second diaphragm unwinding device 11, the first deviation correction assembly, and the second deviation correction assembly are all prior art, and their specific structures will not be described in detail in this application.

[0088] Preferably, a first correction component 3 is provided between the first buffer component 2 and the first cutting component 5, configured to correct the positive pole piece; a second correction component 10 is provided between the second buffer component 9 and the second cutting component 13, configured to correct the negative pole piece.

[0089] The combining device is arranged downstream of the unwinding device, and the positive electrode sheet and the negative electrode sheet are fed into the combining device after being cut, and the first and second diaphragms are also fed into the combining device by the first and second diaphragm unwinding devices, so that the head of the positive electrode sheet is combined with the first diaphragm to form a positive electrode composite layer, and the head of the negative electrode sheet is combined with the second diaphragm to form a negative electrode composite layer; and then the positive electrode composite layer and the negative electrode composite layer are combined to form a combined composite layer;

[0090] Specifically, the combining device includes a first combining device 6, a second combining device 14 and a third combining device 17. The first combining device is configured to combine the head of the positive electrode sheet with the first diaphragm to form a positive electrode composite layer; the second combining device is configured to combine the head of the negative electrode sheet with the second diaphragm to form a negative electrode composite layer; the third combining device is located downstream of the first combining device and is configured to combine the positive electrode composite layer with the negative electrode composite layer to form a combined composite layer.

[0091] 3 , the first combining device 6 includes a first combining roller group, a first driver 613, a second driver 623 and a first meter; the first combining roller group includes a first combining roller and a second combining roller, and a spacing configured to allow the positive electrode sheet 61 and the first diaphragm 71 to pass between the second combining roller and the first combining roller is provided; the first driver is connected to the first combining roller and drives the first combining roller to contact / move away from the first diaphragm, the second driver is connected to the second combining roller and drives the second combining roller to contact / move away from the first diaphragm, and the spacing between the first combining roller and the second combining roller is not greater than the sum of the thicknesses of the positive electrode sheet and the first diaphragm; the first meter is configured to collect the time when the first combining roller group contacts / moves away from the first diaphragm; it should also be noted that the first combining roller 611 and the second combining roller 621 are also respectively provided with a first rotating motor 612 and a second rotating motor 622 respectively configured to drive the first combining roller and the second combining roller to rotate. In some examples, the first driver 613 drives the first combining roller 611 to reciprocate via the first screw assembly 614 ; similarly, the second driver 623 drives the second combining roller 621 to reciprocate via the second screw assembly 624 .

[0092] The second bonding device includes a second bonding roller group, a third driver, a fourth driver, and a second meter; the second bonding roller group includes a fourth bonding roller and a third bonding roller, and a gap configured to allow the negative electrode sheet and the second separator to pass between the fourth bonding roller and the third bonding roller; the third driver is connected to the third bonding roller and drives the third bonding roller to contact / move away from the second separator, and the fourth driver is connected to the fourth bonding roller and drives the fourth bonding roller to contact / move away from the second separator, and the gap between the third bonding roller and the fourth bonding roller is no greater than the sum of the thicknesses of the negative electrode sheet and the second separator; the second meter is configured to collect the time when the second bonding roller group contacts / moves away from the second separator;

[0093] The third combining device includes a fifth combining roller, a sixth combining roller, a fifth driver, a sixth driver and a third meter. A gap is provided between the fifth combining roller and the sixth combining roller for the positive electrode composite layer and the negative electrode composite layer to pass through. The fifth driver is connected to the third combining roller, the sixth driver and the sixth combining roller and drives the fifth combining roller to contact / move away from the first diaphragm / the cathode sheet, drives the sixth combining roller to contact / move away from the second diaphragm, and makes the first diaphragm / the cathode sheet contact with the second diaphragm. The third meter is configured to collect the time when the fifth combining roller contacts / moves away from the first diaphragm / cathode sheet or the sixth combining roller contacts / moves away from the second diaphragm.

[0094] Similarly, the third, fourth, fifth, and sixth coupling rollers are each provided with a rotary motor configured to drive their rotation. Since the rotation of the driving rollers is prior art in the art, they will not be described in detail in this application. Similarly, the reciprocating movement of the third, fourth, fifth, and sixth coupling rollers can also be connected to their corresponding drivers via a screw assembly, and the drivers can respectively drive the third, fourth, fifth, and sixth coupling rollers to reciprocate along their corresponding screws. The driver driving the device to move along the screw assembly is prior art in the art, and therefore will not be described in detail in this application.

[0095] At least the first, third, fifth, and sixth bonding rollers are made of high-resistance conductors or thermally conductive materials, and can generate heat when powered or be connected to a high-temperature heat source to increase their temperature. When the first bonding roller contacts the first diaphragm, the temperature of the first diaphragm can be increased. At the same time, the first driver drives the head of the positive electrode sheet to be pressed against the first diaphragm, thereby achieving hot-press bonding between the head of the positive electrode sheet and the first diaphragm. Since the positive electrode sheet and the first diaphragm are both moving at a constant speed during this process, their relative positions do not change. When the hot-press bonding length of the positive electrode sheet and the first diaphragm reaches the required length, the first driver drives the first bonding roller away from the first diaphragm, the first diaphragm is no longer heated, and the first bonding roller no longer hot-presses the positive electrode sheet and the first diaphragm, so that the positive electrode sheet and the first diaphragm are no longer bonded, thereby achieving partial bonding between the positive electrode sheet and the first diaphragm. Since the first diaphragm and the positive electrode sheet are both moving at a uniform speed during this process, the time it takes for the first bonding roller to move to heat-press the first diaphragm and the positive electrode sheet is collected by the first meter, and by controlling the time difference between the first driver driving the first bonding roller to approach the first diaphragm and move away from the first diaphragm, the bonding length of the positive electrode sheet and the first diaphragm can be controlled. At the same time, since the speed of the first diaphragm and the positive electrode sheet is uniform during the bonding process, and the spacing between two adjacent positive electrode sheets is controllable, the time length that each positive electrode sheet passes through the second bonding roller is approximately constant. Therefore, by controlling the time interval between the first driver driving the first bonding roller to contact the first diaphragm twice, the bonding position of the next positive electrode sheet and the first diaphragm can be controlled to be the head of the positive electrode sheet. The head is the part close to the moving direction of the positive electrode sheet / negative electrode sheet when the positive electrode sheet / negative electrode sheet is bonded to the first diaphragm / second diaphragm.

[0096] Preferably, the first bonding device further includes an image acquisition device configured to capture the position of the positive electrode sheet and provide information for controlling the first actuator to drive the first bonding roller. The image acquisition device may be a CCD camera, and the first actuator may be an existing motor, air pump, liquid pump, or other actuator.

[0097] Similarly, when the third bonding roller contacts the second separator, it raises the temperature of the second separator. Simultaneously, the second driver drives the head of the negative electrode sheet to press against the second separator, thereby achieving thermocompression bonding. Since both the negative electrode sheet and the second separator move simultaneously and at a constant speed during this process, their relative positions do not change. When the thermocompression bonding length of the negative electrode sheet and the second separator reaches the desired length, the third driver drives the third bonding roller away from the second separator, removing the heat from the second separator and the third bonding roller from the negative electrode sheet and the second separator, thereby preventing bonding and achieving partial bonding of the negative electrode sheet and the second separator. Since both the second separator and the negative electrode sheet move at a constant speed during this process, the second meter measures the time it takes for the third bonding roller to thermocompress the second separator and the negative electrode sheet. By controlling the time difference between when the third driver drives the third bonding roller toward and away from the second separator, the bonding length of the negative electrode sheet and the second separator can be controlled to a predetermined length. At the same time, since the speed of the second diaphragm and the negative electrode sheet during the bonding process is uniform and the spacing between two adjacent negative electrode sheets is controllable, the length of time each negative electrode sheet passes through the fourth bonding roller is approximately constant. Therefore, by controlling the time interval between the second driver driving the third bonding roller to contact the second diaphragm twice, the bonding position of the next negative electrode sheet and the second diaphragm can be controlled to be the head of the negative electrode sheet.

[0098] Preferably, the second bonding device further includes an image acquisition device configured to capture the position of the negative electrode sheet and provide information for controlling the third driver to drive the third bonding roller and / or the fourth driver to drive the fourth bonding roller. The image acquisition device may be a CCD camera, and the third driver may be an existing motor, air pump, liquid pump, or other such driver.

[0099] Similarly, when the fifth bonding roller contacts the first diaphragm and the sixth bonding roller contacts the second diaphragm, the temperature of the first and second diaphragms can be increased. Simultaneously, the fifth driver drives the fifth and sixth bonding rollers closer together, pressing the first and second diaphragms against each other, thereby achieving hot-press bonding of the first and second diaphragms. Because the first and second diaphragms are both moving at a constant speed during this process, their relative positions do not change. When the hot-press bonding length of the first and second diaphragms reaches the desired length, the fifth and sixth drivers simultaneously drive the fifth and sixth bonding rollers away from the first and second diaphragms, respectively. The first and second diaphragms are no longer heated, and the fifth and sixth bonding rollers no longer hot-press the first and second diaphragms, preventing bonding between the first and second diaphragms and achieving partial bonding of the first and second diaphragms. Since the first and second diaphragms are both moving at a uniform speed during this process, the third meter measures the time it takes for the fifth and sixth bonding rollers to heat-press the first and second diaphragms. By controlling the time difference between when the fifth driver drives the fifth bonding roller toward and away from the first diaphragm, and the time difference between when the sixth driver drives the sixth bonding roller toward and away from the first diaphragm, the bonding length of the first and second diaphragms of a certain length can be controlled. Furthermore, since the speeds of the first and second diaphragms are uniform during the bonding process, and the spacing between adjacent negative and positive electrode sheets is controllable, the duration that each negative electrode sheet passes through the gap between the fifth and sixth bonding rollers is approximately constant. Therefore, by controlling the time interval between when the fifth and sixth drivers drive the fifth and sixth bonding rollers, respectively, to contact the first and second diaphragms twice, the next bonding position of the first and second diaphragms can be controlled to be between two adjacent positive and negative electrode sheets.

[0100] Preferably, the third bonding device further includes an image acquisition device configured to capture locations where the first and second diaphragms are not bonded to the positive and negative electrode sheets, respectively, to provide information for controlling the fifth and sixth actuators to respectively drive the fifth and sixth bonding rollers. The image acquisition device may be a CCD camera, and the fifth and sixth actuators may be existing actuators such as motors, air pumps, and liquid pumps.

[0101] The winding device is arranged downstream of the combining device and is configured to cut the diaphragm and wind it to form a battery cell; the winding device includes: a continuous diaphragm winding head and a cutting device 19; the continuous diaphragm winding head device includes three winding heads and can realize direct switching of the three winding heads; when the winding head is switched, the guide path is the surface of the winding head, and there is no need to enter the center of the winding needle. At the same time, under the condition of uniform guide speed, the cutting device can uniformly cut the diaphragm on the winding surface (when the diaphragm section between the battery cells passes through the winding needle surface) and adsorb the head of the inner diaphragm. The outer diaphragm is combined with the inner diaphragm due to the previous combining process, forming a composite diaphragm section, realizing the separation between the battery cells at high speed when switching the battery cells and starting the winding of the next battery cell. The winding device can adopt the winding head assembly disclosed in CN115000529A, but compared with the winding head assembly disclosed in the patent, the winding device adopted in this application can omit the film laminating mechanism. Therefore, the specific structure of the winding device will not be described in detail in this application.

[0102] In other embodiments, heating components may be provided on at least the first bonding roller, the third bonding roller, the fifth bonding roller, and / or the sixth bonding roller, respectively. For example, a first heating component may be provided on the first bonding roller, a second heating component may be provided on the third bonding roller, a third heating component may be provided on the fifth bonding roller, and / or a fourth heating component may be provided on the sixth bonding roller, so as to heat the corresponding bonding locations. It should be noted that heating components may be provided on both the fifth bonding roller and the sixth bonding roller, or only one heating component may be provided. Preferably, heating components may be provided on both the fifth bonding roller and the sixth bonding roller, so that the tension, damping, inertia, and dynamic and static friction of the first and second diaphragms during bonding are as close to equal as possible, thereby improving the quality and stability of the winding core.

[0103] The heating component may be an existing heating component, such as a flexible heating sheet connected to an external power source or an array of heating wires. The first, third, fifth and sixth bonding rollers may be existing hot pressing rollers that can be heated at a fixed time.

[0104] In some embodiments, the third combining device can also be an electrostatic combining device. When the third combining device is an electrostatic combining device, the third combining device includes: a fifth combining roller, a sixth combining roller, a fifth driver, a sixth driver, a third meter, a first electrostatic generator 15 and a second electrostatic generator 16; the first electrostatic generator and the second electrostatic generator are located upstream of the fifth combining roller and the sixth combining roller, and are configured to charge the first diaphragm and the second diaphragm with charges of different electrical properties; a gap is provided between the fifth combining roller and the sixth combining roller for the positive electrode composite layer and the negative electrode composite layer to pass through; the fifth driver is connected to the fifth combining roller and the sixth driver is connected to the sixth combining roller and drives the fifth combining roller to contact / move away from the first diaphragm / the cathode sheet, drives the sixth combining roller to contact / move away from the second diaphragm, and makes the first diaphragm / the cathode sheet contact the second diaphragm, and the third meter is configured to collect the time when the fifth combining roller contacts / moves away from the first diaphragm / cathode sheet or the sixth combining roller contacts / moves away from the second diaphragm.

[0105] Among them, the first electrostatic generator and the second electrostatic generator are both existing electrostatic generators, so they will not be described in detail in this application.

[0106] The first combining roller, the second combining roller, the first combining roller, the first combining roller, the first combining roller, the second combining roller. In other embodiments, the first combining component in the first combining device can be a first fixed plate and a first movable plate, the first combining device includes a first driver and a seventh driver, a gap configured to allow the positive electrode sheet and the first diaphragm to pass is set between the first fixed plate and the first movable plate; the first driver is connected to the first movable plate and drives the first movable plate to contact / move away from the first diaphragm, and the gap between the first movable plate and the first fixed plate is not greater than the sum of the thicknesses of the positive electrode sheet and the first diaphragm; the first meter is configured to collect the first combining component. The time when the composite plate group contacts / moves away from the first diaphragm; the seventh driver drives the first combining component to move toward the movement direction of the positive electrode sheet, and the movement speed of the first combining component is equal to the movement speed of the positive electrode sheet; the first movable plate is a heating element that can be heated or a heating component is provided on the first movable plate. During the forward movement of the first diaphragm and the positive electrode sheet, the first movable plate and the first fixed plate are pressed on the first diaphragm and the positive electrode sheet and maintain relative positions unchanged for a certain period of time, and the first diaphragm and the positive electrode sheet are hot-pressed together by heating, so that the bonding length and bonding area of ​​the first diaphragm and the positive electrode sheet are more accurately controlled and the bonding strength is better.

[0107] Similarly, the second combining assembly in the second combining device may be a second fixed plate and a second movable plate, the second combining device including a second driver and an eighth driver, a gap configured to allow the negative electrode sheet and the second diaphragm to pass between the second fixed plate and the second movable plate; the second driver is connected to the second movable plate and drives the second movable plate to contact / move away from the second diaphragm, and the gap between the second movable plate and the second fixed plate is no greater than the sum of the thicknesses of the negative electrode sheet and the second diaphragm; the second meter is configured to collect the time when the second combined plate group contacts / move away from the second diaphragm; The eighth driver drives the second combining component to move toward the movement direction of the negative electrode sheet, and the movement speed of the second combining component is equal to the movement speed of the negative electrode sheet; the second movable plate is a heating element that can be heated or a heating component is provided on the second movable plate. During the forward movement of the second diaphragm and the negative electrode sheet, the second movable plate and the second fixed plate are pressed on the second diaphragm and the negative electrode sheet and maintain relative positions unchanged for a certain period of time, and the second diaphragm and the negative electrode sheet are hot-pressed together by heating, so that the bonding length and bonding area of ​​the second diaphragm and the negative electrode sheet can be more accurately controlled and the bonding strength is better.

[0108] Similarly, the third combining device includes a ninth driver and a tenth driver, and a gap configured to allow the first diaphragm and the second diaphragm to pass through is provided between the third combining plate and the fourth combining plate; the ninth driver is connected to the third combining plate and the fourth combining plate and drives the third combining plate and the fourth combining plate to contact / move away from the first diaphragm and the second diaphragm, and makes the gap between the fourth combining plate and the third combining plate not greater than the sum of the thicknesses of the first diaphragm and the second diaphragm; the third meter is configured to collect the time when the third combining plate group contacts / moves away from the second diaphragm; the tenth driver drives the third combining plate and the fourth combining plate to move in the direction of movement of the combined composite layer, and the movement speed of the third combining plate and the fourth combining plate is equal to the movement speed of the combined composite layer. The third combining plate and the fourth combining plate can both be heating elements that can be heated, or the third combining plate and the fourth combining plate are provided with heating components. During the forward movement of the second diaphragm and the first diaphragm, the fourth combining plate and the third combining plate are pressed on the second diaphragm and the first diaphragm and maintain their relative positions unchanged for a certain period of time, and the second diaphragm and the first diaphragm are hot-pressed and combined by heating, so that the combination length and combination area of ​​the second diaphragm and the first diaphragm can be controlled more accurately and the combination strength is better.

[0109] In some embodiments, the system further includes a controller that is communicatively connected to the first, second, and third combining devices, and the communication connection can be wireless or electrical. The controller can be any control unit in the prior art that can implement information collection, data processing, judgment, and instruction transmission, such as a single-chip microcomputer.

[0110] In some embodiments, a third deviation-correcting device is further provided upstream of the winding device and downstream of the combining device. The third deviation-correcting device is configured to simultaneously correct the positive and negative electrode sheets, thereby aligning the stacked structure formed by the positive electrode sheet, the first separator, the negative electrode sheet, and the second separator. The third deviation-correcting device is conventional technology, and its specific structure is not further described.

[0111] The continuous film feeding and winding mechanism provided in this embodiment works as follows:

[0112] The positive electrode unwinding and cutting device continuously unwinds the positive electrode sheet and cuts the positive electrode sheet into the length required for the battery cell; during the positive electrode sheeting process, the first buffer assembly located between the positive electrode unwinding assembly and the first cutting assembly uses a buffer roller group to pull the distance between the cut positive electrode sheet and the uncut positive electrode sheet, which is the first distance; at the same time, the negative electrode unwinding and cutting device continuously unwinds the positive electrode sheet and cuts the negative electrode sheet into the length required for the battery cell; during the negative electrode sheeting process, the second buffer assembly located between the negative electrode unwinding assembly and the second cutting assembly uses a buffer roller group to pull the distance between the cut negative electrode sheet and the uncut negative electrode sheet, which is the second distance;

[0113] At the same time, the first diaphragm unwinding device and the second diaphragm unwinding device unwind the first diaphragm and the second diaphragm respectively at the same time, and the head of the positive electrode sheet is combined with the first diaphragm through the first combining device to form a first composite section, and the first composite section is used as a traction point so that the positive electrode composite layer formed by the positive electrode sheet 61 and the first diaphragm 71 can be synchronously pulled; the head of the negative electrode sheet 62 is combined with the second diaphragm 72 through the second combining device to form a second composite section, and the second composite section is used as a traction point so that the negative electrode composite layer formed by the negative electrode sheet 62 and the second diaphragm 72 can be synchronously pulled, and then Driven by the diaphragm 72, the positive electrode sheet 61 and the negative electrode sheet 62 move forward synchronously and uniformly in parallel and enter the third combining device. Under the action of the third combining device, the first diaphragm 71 and the second diaphragm 72 are combined to form a combined composite layer, so that the heads of the positive electrode combined composite layer and the negative electrode combined composite layer are combined together, while the tails remain free ends; providing freedom for subsequent correction; the combined positive electrode combined composite layer and the negative electrode combined composite layer are synchronously sent to the winding device after correction, and are wound and cut at the position where the first diaphragm and the second diaphragm are combined to separate the front and rear battery cells. Since the first diaphragm and the second diaphragm are directly combined together, and the subsequent fly-cutting position is the position where the first diaphragm and the second diaphragm are combined, it is not necessary to cut the positive electrode sheet and the negative electrode sheet during the fly-cutting process, thereby avoiding the powder flying caused by the fly-cutting of the positive electrode sheet and the negative electrode sheet; at the same time, since the first diaphragm and the second diaphragm are originally combined together, and the positive electrode sheet and the first diaphragm, the negative electrode sheet and the second diaphragm are also combined together, there will be no misalignment of the layers during the fly-cutting process, and there will be no misalignment of the positive electrode sheet and the negative electrode sheet. At the same time, since the various layers of structure (positive electrode sheet, first diaphragm, negative electrode sheet, second diaphragm) are already combined together before entering the winding device, the feeding speed of each layer can be kept almost absolutely consistent, and the spacing between the positive electrode sheets and the negative electrode sheets has been adjusted. Therefore, there is no need to slow down or stop the speed to adjust the position and speed difference between the positive electrode sheet and the first diaphragm, the negative electrode sheet and the second diaphragm, and the positive electrode sheet and the negative electrode sheet, thereby truly achieving continuous and uniform speed feeding into the winding device for winding and flying cutting. In addition, since in the present application, the positive electrode sheet and the first diaphragm, the negative electrode sheet and the second diaphragm are only combined at the head, the time required for the combination process is relatively short, and the non-stop combination can be achieved in a smaller area when the positive electrode sheet and the first diaphragm, the negative electrode sheet and the second diaphragm are moving at high speed, without slowing down or stopping the speed to provide time and space for the combination, thereby improving the sheet feeding rate. Moreover, since the positive electrode sheet and the first separator, the negative electrode sheet and the second separator are only connected at the head, and the middle and tail are not connected, the tension difference caused by the different inner and outer sides of the winding during the winding process can be partially released, reducing the occurrence of wrinkling and improving the quality of the battery cell.

[0114] During the process of combining, winding, and flying cutting between the previous positive electrode sheet and the first diaphragm, the negative electrode sheet and the second diaphragm, and the first diaphragm and the second diaphragm, the first clamping sheet assembly and the second clamping sheet assembly in the positive electrode unwinding and cutting device and the negative electrode unwinding and cutting device will respectively continue to feed the positive electrode sheet and the negative electrode sheet that are spaced apart from the previous positive electrode sheet and the negative electrode sheet into the first cutting assembly and the second cutting assembly for cutting to form new positive electrode sheets and negative electrode sheets, and as the positive electrode sheet, the negative electrode sheet, the first diaphragm and the second diaphragm advance, they are continuously combined, corrected, wound, and flying cut in sequence to obtain battery cells, realizing continuous and uniform speed feeding and winding. After the previous roll of positive electrode sheet and negative electrode sheet is unwound, when a new roll needs to be replaced, it is only necessary to directly and quickly replace the new roll of positive electrode sheet and negative electrode sheet, and there is no need to stop the machine to replace the positive electrode sheet roll and the negative electrode sheet roll and then speed up.

[0115] It should be noted that the length of the combined head of the positive electrode sheet and the first separator provided in this application does not exceed one cell width, and the length of the combined head of the negative electrode sheet and the second separator does not exceed one cell width. The combined length of the first separator and the second separator does not exceed the first spacing, and during the process of combining the first separator and the second separator, the areas of the first separator and the second separator corresponding to the tail of the previous positive electrode sheet and the negative electrode sheet are not combined.

[0116] In the present application, the width of the battery cell should be understood as the width of the outer surface of the wound battery cell in a direction perpendicular to the width direction of the positive electrode sheet and the negative electrode sheet.

[0117] The continuous film feeding and winding mechanism provided in the present application can realize continuous uniform film feeding and winding at a speed of more than 600 mm / s, and can even realize continuous uniform film feeding and winding at a speed of more than 1000 mm / s, or even more than 2000 mm / s, that is, the unwinding speed of the first diaphragm and the second diaphragm can reach more than 600 mm / s, or even higher, such as more than 1000 mm / s, or more than 2000 mm / s. When the first diaphragm and the positive electrode sheet are combined, the speed of the positive electrode sheet and the first diaphragm can reach more than 600 mm / s, or even higher, such as more than 1000 mm / s, or more than 2000 mm / s; when the negative electrode sheet and the second diaphragm .... The traveling speed of the negative electrode sheet and the second separator can reach more than 600 mm / s, or even higher, such as more than 1000 mm / s or more than 2000 mm / s; when the first separator and the second separator are combined, the traveling speed of the positive electrode combination composite layer and the negative electrode combination composite layer can reach more than 600 mm / s, or even higher, such as more than 1000 mm / s or more than 2000 mm / s; after the positive electrode combination composite layer and the negative electrode combination composite layer are combined, they can be fed into the winding device at a speed of more than 600 mm / s, and even their winding speed can reach more than 1000 mm / s or even more than 2000 mm / s, and the sheets can be fed continuously at a uniform speed during this process.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application. Industrial Applicability

[0119] In summary, the present application provides a winding process of continuous sheet feeding and winding, which can realize the correction of positive and negative electrode sheets and adjust the tension during the winding process, thereby reducing uneven tension and wrinkles; it can also reduce the time and cost required for the combination of the positive electrode sheet and the first diaphragm, and the time and cost required for the combination of the negative electrode sheet and the second diaphragm, thereby reducing the difficulty of combining the electrode sheet and the diaphragm, and it can also increase the winding speed of the battery cell.

[0120] The present application also provides a continuous sheet feeding and winding mechanism that achieves continuous, uniform, and high-speed material feeding, and its integration is simple and easy to promote and use. The continuous sheet feeding and winding mechanism provided by the present application can achieve continuous sheet feeding and winding of the positive electrode sheet, the negative electrode sheet, the first separator, and the second separator at a speed of more than 600 mm / s, and can even achieve continuous sheet feeding and winding at more than 2000 mm / s.

Claims

1. Continuous film feeding and winding process, characterized in that: The method comprises a first combining process, a second combining process and a winding and cutting process; The first bonding process includes a positive electrode sheet-separator bonding process and a negative electrode sheet-separator bonding process that are performed simultaneously; The positive electrode sheet-separator bonding process includes bonding the head of the positive electrode sheet and the first separator to form a positive electrode composite layer; the negative electrode sheet-separator bonding process includes bonding the head of the negative electrode sheet and the second separator to form a negative electrode composite layer; wherein the positive electrode sheet is formed by cutting the positive electrode sheet; and the negative electrode sheet is formed by cutting the negative electrode sheet; The second combining step includes: combining the positive electrode composite layer and the negative electrode composite layer to form a combined composite layer; The winding and cutting process includes: feeding the combined composite layer into a winding machine for winding, cutting, and winding the next battery cell.

2. The continuous film feeding and winding process according to claim 1, characterized in that: In the winding and cutting process, the combined composite layer is fed into the winding machine at a speed of not less than 600 mm / s for winding.

3. The continuous film feeding and winding process according to claim 1 or 2, characterized in that: The combined length of each of the positive electrode sheets and the first separator is no greater than 1.5 times the outer circumference of the formed battery cell; and / or The combined length of each of the negative electrode plates and the second separator is no more than 1.5 times the outer circumference of the formed battery cell; and / or The combined length of the positive electrode composite layer and the negative electrode composite layer is no greater than the outer perimeter of the formed battery cell.

4. The continuous film feeding and winding process according to claim 3, characterized in that: The area of each positive electrode sheet combined with the first separator does not exceed the vertical projection area of the obtained battery cell on the plane in the width direction; The area where each of the negative electrode plates is combined with the second separator does not exceed the vertical projection area of the obtained battery cell on the plane where the width direction is located.

5. The continuous film feeding and winding process according to any one of claims 1 to 4, characterized in that: The combined composite layer is a composite structure formed by stacking the positive electrode sheet, the first separator, the negative electrode sheet, and the second separator in sequence; There is a first spacing between adjacent positive electrode sheets; there is a second spacing between adjacent negative electrode sheets; and there is an overlapping area when the projections of the first spacing and the second spacing in a direction perpendicular to the first diaphragm / the second diaphragm are in a direction perpendicular to the first diaphragm / the second diaphragm; The positive electrode composite layer and the negative electrode composite layer are partially combined in the overlapping area, and a gap exists between the combined area of the positive electrode composite layer and the negative electrode composite layer and the tail of the negative electrode sheet.

6. The continuous film feeding and winding mechanism according to claim 5, characterized in that: The bonding area of the positive electrode composite layer and the negative electrode composite layer includes a first area and a second area, the first area is a part of the overlapping area; the second area includes the area corresponding to the bonding part of the positive electrode plate and the first diaphragm; the first area and the second area are connected into one piece.

7. The continuous film feeding and winding mechanism according to any one of claims 1 to 6, characterized in that: The positive electrode composite layer and the negative electrode composite layer corresponding to the tail of the positive electrode sheet and the tail of the negative electrode sheet are not combined.

8. The continuous film feeding and winding mechanism according to any one of claims 1 to 7, characterized in that: The positive electrode composite layer and the negative electrode composite layer are electrostatically bonded; and / or The head of the positive electrode plate is bonded or glued to the first separator by hot pressing, and the head of the negative electrode plate is bonded or glued to the second separator by hot pressing.

9. A continuous film feeding and winding mechanism, characterized in that: include: An unwinding device, comprising a positive electrode unwinding and cutting device, a negative electrode unwinding and cutting device, a first diaphragm unwinding device and a second diaphragm unwinding device; a combining device, disposed downstream of the unwinding device, configured to combine the head of the positive electrode sheet with the first separator to form a positive electrode composite layer, combine the head of the negative electrode sheet with the second separator to form a negative electrode composite layer, and combine the positive electrode composite layer with the negative electrode composite layer to form a combined composite layer; wherein the positive electrode sheet is formed by cutting the positive electrode sheet; and the negative electrode sheet is formed by cutting the negative electrode sheet; a winding device, disposed downstream of the combining device, configured to cut the first diaphragm and the second diaphragm and wind them to form a battery core; The head portion is a portion close to the moving direction of the positive electrode sheet / the negative electrode sheet when the positive electrode sheet / the negative electrode sheet is combined with the first diaphragm / the second diaphragm.

10. The continuous film feeding and winding mechanism according to claim 9, characterized in that: The combining device includes a first combining device, a second combining device and a third combining device, wherein the first combining device is configured to combine the head of the positive electrode sheet with the first separator to form a positive electrode composite layer; The second combining device is configured to combine the head of the negative electrode plate with the second separator to form a negative electrode composite layer; The third combining device is located downstream of the first combining device and the second combining device, and is configured to combine the positive electrode composite layer and the negative electrode composite layer to form a combined composite layer.

11. The continuous film feeding and winding mechanism according to claim 10, characterized in that: The first bonding device is a heat-pressing bonding device or an adhesive bonding device; The second bonding device is a heat-pressing bonding device or an adhesive bonding device; The third bonding device is a hot pressing bonding device or an electrostatic bonding device.

12. The continuous film feeding and winding mechanism according to claim 10 or 11, characterized in that: The first combining device includes a first combining assembly, a first driver, and a first meter; the first combining assembly includes a first combining member and a second combining member, and a gap configured to allow the positive electrode sheet and the first diaphragm to pass through is provided between the first combining member and the second combining member; The first driver is connected to the first coupling member and drives the first coupling member to contact or move away from the first diaphragm, and the distance between the first coupling member and the second coupling member is no greater than the sum of the thicknesses of the positive electrode sheet and the first diaphragm; The first meter is configured to collect the time when the first binding component contacts or moves away from the first diaphragm; The second coupling device includes a second coupling assembly, a third driver, and a second meter; the second coupling assembly includes a third coupling member and a fourth coupling member, a gap configured to allow the negative electrode sheet and the second diaphragm to pass therethrough is provided between the third coupling member and the fourth coupling member; the third driver is connected to the third coupling member and drives the third coupling member to contact with or move away from the second diaphragm, and ensures that the gap between the third coupling member and the fourth coupling member is no greater than the sum of the thicknesses of the negative electrode sheet and the second diaphragm; The second meter is configured to collect the time when the second binding component contacts / keeps away from the second diaphragm; The third combining device includes a fifth combining member, a sixth combining member, a fifth driver, a sixth driver and a third meter, wherein a gap is provided between the fifth combining member and the sixth combining member for the positive electrode composite layer and the negative electrode composite layer to pass through; the fifth driver is connected to the fifth combining member and drives the fifth combining member to contact with or move away from the first diaphragm / the cathode sheet; and / or The sixth driver is connected to the sixth coupling member and drives the sixth coupling member to contact / move away from the second diaphragm, so that the first diaphragm / the cathode plate contacts the second diaphragm, and the third meter is configured to collect the time when the fifth coupling member contacts / moves away from the first diaphragm / cathode plate or the sixth coupling member contacts / moves away from the second diaphragm.

13. The continuous film feeding and winding mechanism according to claim 12, characterized in that: The first bonding device includes a first heating assembly disposed on the first bonding assembly and configured to heat the first bonding assembly; The second bonding device includes a second heating assembly disposed on the second bonding assembly and configured to heat the second bonding assembly; The third combining device includes a third heating assembly and a fourth heating device, and the third heating assembly and the fourth heating device are respectively disposed on the fifth combining piece and the sixth combining piece and are configured to heat the fifth combining piece and the sixth combining piece.

14. The continuous film feeding and winding mechanism according to claim 12 or 13, characterized in that: The first combining device further includes a seventh driver, the seventh driver driving the first combining assembly to move toward the moving direction of the positive electrode sheet, and the moving speed of the first combining assembly is equal to the moving speed of the positive electrode sheet; The second combining device further includes an eighth driver, the eighth driver driving the second combining assembly to move toward the movement direction of the negative electrode sheet, and the movement speed of the second combining assembly is equal to the movement speed of the negative electrode sheet; The third combining device includes a ninth driver, which drives the fifth and sixth combining members to move in the direction of movement of the combined composite layer, and the moving speed of the fifth and sixth combining members is equal to the moving speed of the combined composite layer.

15. The continuous film feeding and winding mechanism according to any one of claims 10 to 14, characterized in that: The system further includes a controller, which is communicatively connected with the first combining device, the second combining device, and the third combining device.

16. The continuous film feeding and winding mechanism according to any one of claims 9 to 15, characterized in that: The positive electrode unwinding and cutting device includes a positive electrode unwinding assembly, a first buffer assembly, a first pinching sheet assembly, and a first cutting assembly arranged in sequence; the positive electrode unwinding assembly unwinds the positive electrode sheet to the first cutting assembly, and the first cutting assembly cuts the positive electrode sheet into positive electrode sheets; the first buffer assembly is located between the positive electrode unwinding assembly and the first cutting assembly, and is configured to increase the distance between two adjacent positive electrode sheets; the first pinching sheet assembly is located between the first buffer assembly and the first cutting assembly, and is configured to pinch and feed the positive electrode sheet to the first cutting assembly; The negative electrode unwinding and cutting device includes a negative electrode unwinding assembly, a second buffer assembly, a second pinching sheet assembly and a second cutting assembly; the negative electrode unwinding assembly unwinds the negative electrode sheet to the second cutting assembly, and the second cutting assembly cuts the negative electrode sheet into negative electrode sheets; the second buffer assembly is located between the negative electrode unwinding assembly and the second cutting assembly, and is configured to increase the distance between two adjacent negative electrode sheets; the second pinching sheet assembly is located between the second buffer assembly and the second cutting assembly, and is configured to pinch and feed the negative electrode sheet to the second cutting assembly.

17. The continuous film feeding and winding mechanism according to claim 16, characterized in that: A first deviation-correcting component is further provided between the first buffer component and the first cutting component; A second deviation-correcting assembly is further provided between the second buffer assembly and the second cutting assembly.

18. The continuous film feeding and winding mechanism according to any one of claims 9 to 17, characterized in that: The first diaphragm unwinding device and the second diaphragm unwinding device unwind synchronously and continuously at a uniform speed; The unwinding speeds of the first diaphragm unwinding device and the second diaphragm unwinding device are equal to the forward speeds of the negative electrode composite layer and the positive electrode composite layer in the combining device.

19. The continuous film feeding and winding mechanism according to any one of claims 9 to 18, characterized in that: The unwinding speed of the positive electrode sheet, the unwinding speed of the negative electrode sheet, the unwinding speed of the first diaphragm and the unwinding speed of the second diaphragm are all not less than 600 mm / s.

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