Composite rolling mechanism, winding device and winding production line

Abstract

The present application is suitable for the technical field of battery production, and provides a composite rolling mechanism, a winding device, and a winding production line. The composite rolling mechanism comprises a first composite assembly and a second composite assembly, the first composite assembly having a first gap used to permit a first separator, a first pole piece and a second separator to pass through, and the second composite assembly comprising a first composite roller and a second composite roller which are arranged at an interval; the first composite roller is used to have rolling friction contact with a first sheet body, the first sheet body being a composite sheet body formed from the first separator, the first pole piece and the second separator after passing through the first composite assembly; the second composite roller is used to have rolling friction contact with a second pole piece, a second gap being formed between the second composite roller and the first composite roller, and the linear speed of the second composite roller being slower than the linear speed of the first composite roller. The composite rolling mechanism, the winding device and the winding production line provided by the present application can, to a certain extent, reduce the risk of wrinkles in a pole piece located on an inner ring.

Description

Roller lamination mechanism, winding equipment and winding production line

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on September 28, 2023, with application number 202322662103.1 and invention name “Rolling composite mechanism, winding equipment and winding production line”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of battery production technology, and in particular relates to a rolling composite mechanism, a winding device, and a winding production line. Background Art

[0003] Battery electrode assemblies can be manufactured using either winding or lamination processes. The winding process offers advantages such as ease of spot welding, relatively simple production control, and convenient slitting. Therefore, the winding process is widely used. However, the inner electrode sheets of current wound electrode assemblies are prone to wrinkling.

[0004] Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a rolling composite mechanism, a winding device and a winding production line, aiming to improve the technical problem that the inner ring pole pieces of the wound electrode assembly are prone to wrinkles. Technical Solutions

[0006] The technical solution adopted in the embodiment of this application is:

[0007] In the first aspect, an embodiment of the present application provides a rolling composite mechanism, comprising a first composite assembly and a second composite assembly arranged in sequence along the conveying direction of the first electrode piece, the first composite assembly having a first gap for allowing the first diaphragm, the first electrode piece and the second diaphragm to pass through, the second composite assembly comprising a first composite roller and a second composite roller arranged at intervals; the first composite roller is used for rolling friction contact with the first sheet; the first sheet is a composite sheet formed after the first diaphragm, the first electrode piece and the second diaphragm pass through the first composite assembly; the second composite roller is used for rolling friction contact with the second electrode piece, and there is a second gap between the second composite roller and the first composite roller for allowing the first sheet and the second electrode piece to pass through, and the first sheet and the second electrode piece form a final composite body after passing through the second composite assembly; the linear speed of the second composite roller is less than the linear speed of the first composite roller.

[0008] The rolling composite mechanism provided in the embodiment of the present application includes a first composite component and a second composite component. The first composite component can be used to composite the first diaphragm, the first electrode piece and the second diaphragm into a composite sheet body (i.e., the first sheet body). The second composite component can be used to composite the above-mentioned composite sheet body and the second electrode piece into a final composite body. Since the linear speeds of the first composite roller and the second composite roller in the second composite component are different, the linear speed of the second composite roller is less than the linear speed of the first composite roller. In this way, the flattened length of the second electrode piece in the final composite body formed after composited by the second composite component can be less than the flattened length of the first electrode piece, so that the second electrode piece in the final composite body is in a flattened state and the first electrode piece is in a bent state. In this way, when the final composite body is subsequently wound, the risk of wrinkles on the second electrode piece located in the inner circle can be reduced to a certain extent.

[0009] In some embodiments, a first recessed structure is provided on the roller surface of the first composite roller, and the first recessed structure is used to provide a clearance space for at least a portion of the target diaphragm; wherein the target diaphragm is the first diaphragm or the second diaphragm in the first sheet that contacts the first composite roller. In the solution provided in this embodiment, the provision of the first recessed structure can, to a certain extent, reduce the roller pressure exerted on the first and second diaphragms in the area corresponding to the first recessed structure when the first sheet passes through the second gap, thereby preventing the first and second diaphragms in this area from being excessively rolled and retaining a relatively large thickness. This ensures that the spacing between the first and second pole pieces meets preset requirements, resulting in a higher battery yield.

[0010] In some embodiments, the target diaphragm has a coating, and the depth of the first recessed structure is greater than or equal to the thickness of the coating. The structure provided in this embodiment can prevent the coating in the area of ​​the target diaphragm corresponding to the first recessed structure from being squeezed and thinned, or reduce the risk of squeezing and thinning. This can preserve the function of the coating or minimize damage, thereby ensuring that the spacing between the first and second electrode sheets meets preset requirements, resulting in a higher battery yield.

[0011] In some embodiments, the first recessed structure is a first annular groove disposed around the outer circumference of the first composite roller. The first recessed structure, using the configuration provided in this embodiment, is simple and easy to manufacture. This embodiment eliminates the need to excessively widen a single first annular groove, ensuring that the areas of greater thickness between the first and second diaphragms effectively separate the first and second electrode sheets.

[0012] In some embodiments, multiple first annular grooves are provided, spaced apart along the axial direction of the first composite roller. This embodiment eliminates the need to excessively widen a single first annular groove, effectively separating the first and second diaphragms from the first and second pole pieces. The width of a single first annular groove refers to its dimension in the axial direction of the first composite roller.

[0013] In some embodiments, the width of a single first annular groove is greater than or equal to the distance between two adjacent first annular grooves. Using the solution provided by this embodiment, the distance between two adjacent regions of greater thickness in the first and second diaphragms can be made smaller than the width of the corresponding regions, thereby enabling the first and second diaphragms to effectively separate the first and second pole pieces.

[0014] In some embodiments, the coverage area of ​​the first recessed structure is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller. Using the solution provided by this embodiment, the area of ​​the thicker region of the first and second diaphragms can account for more than 50% of the total area of ​​the corresponding surfaces of the diaphragms, thereby effectively separating the first and second electrode sheets.

[0015] In some embodiments, the first concave structure is connected to the roller surface of the first composite roller via a first curved surface. The structure provided by this embodiment can reduce the risk of wear during the contact between the first sheet and the first concave structure to a certain extent.

[0016] In some embodiments, the first curved surface is a chamfered surface. This structure is easy to manufacture.

[0017] In some embodiments, a second recessed structure is provided on the roller surface of the second composite roller, and the second recessed structure is used to provide a clearance space for at least a portion of the second electrode sheet. In the solution provided in this embodiment, the provision of the second recessed structure can, to a certain extent, reduce the roller pressure exerted on the first and second diaphragms in the areas corresponding to the second recessed structure when the second electrode sheet and the first sheet pass through the second gap. This prevents the first and second diaphragms in these areas from being excessively rolled, allowing them to retain a relatively large thickness. This ensures that the spacing between the first and second electrode sheets meets preset requirements, resulting in a higher battery yield.

[0018] In some embodiments, the second concave structure is a second annular groove disposed around the outer circumference of the second composite roller. The second concave structure adopts the arrangement provided in this embodiment, which has a simple structure and is easy to prepare.

[0019] In some embodiments, the second composite roller is provided with a plurality of second annular grooves, all of which are spaced apart along the axial direction of the second composite roller. This embodiment eliminates the need to excessively widen a single second annular groove, while still allowing the first and second diaphragms to effectively separate the first and second electrode pieces.

[0020] In some embodiments, the second concave structure is connected to the roller surface of the second composite roller via a second curved surface. The structure provided by this embodiment can reduce the risk of wear during the contact between the second pole piece and the second concave structure to a certain extent.

[0021] In some embodiments, the second curved surface is a chamfered surface. This structure is easy to prepare.

[0022] In some embodiments, the first concave structure and the second concave structure are staggered, so that the sizes of the first and second concave structures can be set smaller, so that the final composite body can meet the preset requirements and have little impact on the structural stability of the first composite roller and the second composite roller.

[0023] In some embodiments, a plurality of the first and second recessed structures are provided, with all first recessed structures spaced apart along the axial direction of the first composite roller, and all second recessed structures spaced apart along the axial direction of the second composite roller. This allows the first and second recessed structures to be smaller in size, ensuring that the final composite product meets predetermined requirements while minimizing the impact on the structural stability of the first and second composite rollers.

[0024] In some embodiments, the projection of at least one of the first recessed structures on the surface of the second composite roller is located between two of the second recessed structures. Compared to a case where the projections of all first recessed structures on the surface of the second composite roller overlap with the second recessed structures, this can further reduce the size of the first and / or second recessed structures, thereby reducing the adverse effects of the first and second recessed structures on the structural stability of the first and second composite rollers.

[0025] In some embodiments, the projection of any one of the first recessed structures on the roller surface of the second composite roller is located between two of the second recessed structures. This allows for further reduction in the size of the first and / or second recessed structures, compared to when at least some of the projections of the first recessed structures on the roller surface of the second composite roller overlap with the second recessed structures, thereby reducing the adverse effects of the first and second recessed structures on the structural stability of the first and second composite rollers.

[0026] In some embodiments, the width of at least one of the second recessed structures is greater than or equal to the distance between the projections of the second recessed structure and the adjacent first recessed structure. Using the solution provided in this embodiment, the distance between two adjacent regions of greater thickness in the first and second diaphragms can be made smaller than the widths of the corresponding regions, thereby enabling the regions of greater thickness in the first and second diaphragms to effectively separate the first and second electrode sheets.

[0027] In some embodiments, the total coverage area of ​​all recessed structures is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller or the second composite roller. Using the solution provided by this embodiment, the area of ​​the region with greater thickness in the first diaphragm can account for more than 50% of the total area of ​​the same surface of the first diaphragm, and the area of ​​the region with greater thickness in the second diaphragm can account for more than 50% of the total area of ​​the same surface of the second diaphragm. This allows the region with greater thickness in the first and second diaphragms to effectively separate the first and second electrode sheets.

[0028] In some embodiments, the outer diameter of the first composite roller is different from the outer diameter of the second composite roller, which facilitates design so that the linear speed of the second composite roller is lower than the linear speed of the first composite roller.

[0029] In some embodiments, the first composite roller and the second composite roller have different rotational speeds, and for design convenience, the linear speed of the second composite roller is smaller than the linear speed of the first composite roller.

[0030] In some embodiments, multiple first composite rollers are provided, all having the same outer diameter and rotational speed, all being arranged around the second composite roller, and the gaps between any two first composite rollers and the second composite rollers being the same. This embodiment provides for improved composite and conveying performance of the first electrode body and the second electrode sheet as they pass through the second gap.

[0031] In some embodiments, the first composite assembly includes a third composite roller and a fourth composite roller arranged at intervals, with the first gap between the third composite roller and the fourth composite roller. The solution provided in this embodiment has a simple structure for the first composite assembly and is easy to install and use.

[0032] In some embodiments, the roll-to-lamination mechanism further includes a first guide roller, a second guide roller, and a third guide roller located upstream of the first composite assembly. The first guide roller is configured to contact the first diaphragm and guide the first diaphragm toward the first composite assembly. The second guide roller is configured to contact the second diaphragm and guide the second diaphragm toward the first composite assembly. The third guide roller is configured to contact the first pole piece and guide the first pole piece toward the first composite assembly. The roll-to-lamination mechanism employing the structure provided in this embodiment has more comprehensive functionality and is more convenient to use.

[0033] Secondly, embodiments of the present application provide a winding device, including the roll-combining mechanism provided by any of the above embodiments. The winding device provided by embodiments of the present application, including the roll-combining mechanism of any of the above solutions, can, to a certain extent, reduce the risk of wrinkles in the second pole piece located in the inner ring.

[0034] Thirdly, embodiments of the present application provide a winding production line, including the winding apparatus provided by any of the above embodiments. The winding production line provided by embodiments of the present application, including the winding apparatus of any of the above solutions, can, to a certain extent, reduce the risk of wrinkling of the second pole piece located in the inner ring.

[0035] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] FIG1 is a schematic structural diagram of a roll-combining mechanism according to some embodiments of the present application;

[0038] FIG2 is a schematic structural diagram of a second composite component in a roll-combining mechanism in some embodiments of the present application;

[0039] FIG3 is a schematic cross-sectional view of a first diaphragm used in some embodiments of the present application;

[0040] FIG4 is a schematic diagram of a partial cross-sectional structure of a first composite roller in a roll-composite mechanism according to some embodiments of the present application;

[0041] FIG5 is a schematic structural diagram of a second composite component in a roll-combining mechanism in other embodiments of the present application;

[0042] FIG6 is a schematic diagram of a partial cross-sectional structure of a second composite component in a roll-combining mechanism according to other embodiments of the present application;

[0043] FIG. 7 is a schematic diagram of the exploded structure of the roll-combining mechanism according to other embodiments of the present application.

[0044] The reference numerals in the specific embodiment are as follows: 10, first pole piece; 20, first diaphragm; 21, substrate; 22, coating; 30, second diaphragm; 40, first sheet; 50, second pole piece; 60, final composite; 100, first composite assembly; 110, third composite roller; 120, fourth composite roller; 200, second composite assembly; 210, first composite roller; 220, second composite roller; 310, first recessed structure; 320, second recessed structure; 410, first curved surface; 420, second curved surface; 500, first guide roller; 600, second guide roller; 700, third guide roller; X, conveying direction of the first pole piece; h1, depth of the first recessed structure; h2, depth of the second recessed structure; a, The thickness of the coating; b1, the width of the first annular groove; b2, the width of the second annular groove; c1, the distance between two adjacent first annular grooves; c2, the distance between the second concave structure and the projection pattern of the adjacent first concave structure; D1, the outer diameter of the first composite roller; D2, the outer diameter of the second composite roller. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit this application.

[0046] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0047] In order to illustrate the technical solution provided by this application, a detailed description is given below with reference to specific drawings and embodiments.

[0048] Currently, market developments indicate that power batteries are becoming increasingly widely used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As power battery applications continue to expand, market demand is also growing.

[0049] Battery electrode assemblies can be manufactured using either winding or lamination processes. The winding process offers advantages such as ease of spot welding, relatively simple production control, and convenient slitting. Therefore, the winding process is widely used.

[0050] An electrode assembly generally includes a first diaphragm, a first electrode sheet, a second diaphragm, and a second electrode sheet stacked in layers. In related art, when an electrode assembly is prepared through a winding process, the first diaphragm and the first electrode sheet are first combined into a composite sheet, the second diaphragm and the second electrode sheet are then combined into a composite sheet, and the two composite sheets are then combined into a final composite body. The final composite body is then rolled and extruded into a cylindrical, elliptical, or square shape using a winding needle.

[0051] When the above-mentioned preparation method is used, the first electrode sheet and the second electrode sheet in the final composite body will be of equal length. After the electrode assembly is wound and formed, the first electrode sheet and the second electrode sheet will both be in a wound state, and the first electrode sheet will be located on the outside of the second electrode sheet. In this way, during the winding process, in order to meet the winding requirements, the second electrode sheet will be at least partially squeezed and wrinkled.

[0052] In order to improve the above problems, an embodiment of the present application provides a rolling composite mechanism, which includes a first composite component and a second composite component. The first composite component can be used to composite the first diaphragm, the first electrode piece and the second diaphragm into a composite sheet body, and the second composite component can be used to composite the above composite sheet body and the second electrode piece into a final composite body. Since the linear speeds of the first composite roller and the second composite roller in the second composite component are different, the linear speed of the second composite roller is less than the linear speed of the first composite roller. In this way, the flattened length of the second electrode piece in the final composite body formed after composited by the second composite component can be less than the flattened length of the first electrode piece, so that the second electrode piece in the final composite body is in a flattened state and the first electrode piece is in a bent state. In this way, when the final composite body is subsequently wound, the risk of wrinkles on the second electrode piece located in the inner circle can be reduced to a certain extent.

[0053] The roll-compounding mechanism disclosed in the embodiments of the present application can be used in a winding device or a winding production line in a winding process. The winding device generally includes a roll-compounding mechanism. In addition, the winding device may also include a winding needle located downstream of the roll-compounding mechanism, or other equipment. The roll-compounding mechanism is used to combine the first diaphragm, the first pole piece, the second diaphragm, and the second pole piece into a final composite body, and the winding needle is used to wind the final composite body into shape.

[0054] The winding production line generally includes the above-mentioned winding equipment. In addition, the winding production line may also include a feeding mechanism or other equipment located upstream of the roll-laminating mechanism. The feeding mechanism may include a first diaphragm feeding mechanism, a first electrode sheet feeding mechanism, and a second diaphragm feeding mechanism. The above-mentioned location upstream of the roll-laminating mechanism means that during the production process, the relevant materials (such as the first diaphragm, the first electrode sheet, and the second diaphragm) will first pass through the feeding mechanism and then pass through the roll-laminating mechanism.

[0055] Referring to Figure 1 , an embodiment of the present application provides a roll-to-roll lamination mechanism. The roll-to-roll lamination mechanism includes a first composite assembly 100 and a second composite assembly 200, arranged sequentially along a conveying direction X of a first electrode sheet 10. The first composite assembly 100 has a first gap for passage of the first diaphragm 20, the first electrode sheet 10, and the second electrode sheet 30. The second composite assembly 200 includes a first composite roller 210 and a second composite roller 220, spaced apart from each other. The first composite roller 210 is in rolling frictional contact with the first sheet 40. The first sheet 40 is the composite sheet formed after the first diaphragm 20, the first electrode sheet 10, and the second electrode sheet 30 pass through the first composite assembly 100. The second composite roller 220 is in rolling frictional contact with the second electrode sheet 50. A second gap is defined between the second composite roller 220 and the first composite roller 210 for passage of the first electrode sheet 40 and the second electrode sheet 50. The first electrode sheet 40 and the second electrode sheet 50 pass through the second composite assembly 200 to form a final composite. The linear velocity of the second composite roller 220 is lower than that of the first composite roller 210.

[0056] The first composite component 100 is used to roll the first diaphragm 20, the first electrode piece 10 and the second diaphragm 30 so that the three can be bonded and compounded into a composite sheet body under the action of an adhesive. The first composite component 100 includes at least two sets of composite rollers, and there is a first gap between the two sets of composite rollers that allows the stacked first diaphragm 20, the first electrode piece 10 and the second diaphragm 30 to pass through, and the first composite component 100 can make the first diaphragm 20, the first electrode piece 10 and the second diaphragm 30 bonded and compounded into a composite sheet body, that is, the first sheet body 40. In addition, the first composite component 100 can also include conveying rollers for conveying the first diaphragm 20, the first electrode piece 10 and / or the second diaphragm 30, etc., which can be determined according to the needs of use. The width of the above-mentioned first gap is generally equivalent to the sum of the thicknesses of the first diaphragm 20, the first electrode piece 10 and the second diaphragm 30 when they are stacked in sequence and in a bonded state, or slightly smaller than the sum of the thicknesses of the three. Since the first composite assembly 100 generally includes two composite rollers spaced apart from each other, the width of the first gap refers to the dimension between the two composite rollers in the first composite assembly 100, along an axis perpendicular to the composite rollers in the first composite assembly 100. Of course, when the first composite assembly 100 includes more than two composite rollers, the width of the first gap refers to the dimension between two spaced-apart composite rollers in the first composite assembly 100, along an axis perpendicular to the composite rollers in the first composite assembly 100.

[0057] One of the first pole piece 10 and the second pole piece 50 is a cathode pole piece, and the other is an anode pole piece. That is, there are two situations: the first pole piece 10 is a cathode pole piece and the second pole piece 50 is an anode pole piece; the second pole piece 10 is an anode pole piece and the second pole piece 50 is a cathode pole piece.

[0058] The second composite assembly 200 is used to roll the first sheet 40 and the second pole piece 50 so that the two are composited into a final composite body 60. The second composite assembly 200 may include only the first composite roller 210 and the second composite roller 220. It may also include the first composite roller 210 and the second composite roller 220 and other structures, such as a fixing structure (such as a bracket, frame, etc.) for fixing the position of the first composite roller 210 and the second composite roller 220, an adjustment structure for adjusting the distance between the first composite roller 210 and the second composite roller 220, etc. The specific structure can be determined according to the actual use requirements.

[0059] The first composite roller 210 can be a flat roller with a smooth surface, or a roller with a convex structure or a concave structure on the surface, which can be determined according to the use requirements. The number of the first composite roller 210 can be one or more, which can be determined according to the use requirements.

[0060] The second composite roller 220 can be a flat roller with a smooth surface, or a roller with a convex structure or a concave structure on the surface, which can be determined according to the use requirements. The number of the second composite roller 220 can be one or more, which can be determined according to the use requirements.

[0061] A spaced arrangement means that the outer walls of the first composite roller 210 and the second composite roller 220 do not touch, and a second gap exists between them, allowing the first sheet 40 and the second electrode piece 50 to pass through in a stacked form. The width of this second gap is generally equivalent to, or slightly less than, the sum of the thicknesses of the first sheet 40 and the second electrode piece 50 when stacked and bonded. The width of the second gap refers to the distance between the first composite roller 210 and the second composite roller 220 along an axial direction perpendicular to the first composite roller 210.

[0062] The second gap can be set as a fixed gap or an adjustable gap according to the needs of use. When the second gap is a fixed gap, it can be achieved by fixing the first composite roller 210 and the second composite roller 220 on the bracket, respectively, and the gap between them cannot be adjusted. When the second gap is an adjustable gap, it can be achieved by fixing the first composite roller 210 on the bracket and installing the second composite roller 220 on the bracket in a sliding or liftable manner, or by installing the first composite roller 210 and the second composite roller 220 on the bracket in a sliding or liftable manner. Of course, in other cases, the first composite roller 210 and the second composite roller 220 can also be set in other ways to make the second gap between them a fixed gap or an adjustable gap, and this is not the only limitation here.

[0063] Rolling friction contact with the first sheet 40 means that the first composite roller 210 can rotate around its own axis, and can always maintain surface contact or line contact with the first sheet 40 while rotating, and there is friction between the contact areas of the two. The first sheet 40 can be transported forward under the drive of the first composite roller 210.

[0064] Rolling friction contact with the second pole piece 50 means that the second composite roller 220 can rotate around its own axis of rotation, and can always maintain surface contact or line contact with the final composite body 60 while rotating, and there is friction between the contact areas of the two. The final composite body 60 can be transported forward under the drive of the second composite roller 220.

[0065] Linear velocity is the speed of any point on an object in circular motion about a fixed axis. It is generally defined as the instantaneous speed of a particle (or any point on an object) in curved motion (including circular motion). The linear velocity of the second composite roller 220 is lower than that of the first composite roller 210. This means that the speed of any point on the surface of the second composite roller 220 in circular motion about its axis is lower than the speed of any point on the surface of the first composite roller 210 in circular motion about its axis.

[0066] The operation process of using the roller pressing lamination mechanism provided in the embodiment of the present application to laminate the electrode and the diaphragm is as follows:

[0067] Adhesive can be first coated on the first diaphragm 20 and the second diaphragm 30, and then the first diaphragm 20, the first electrode 10 and the second diaphragm 30 are transported to the first gap of the first composite component 100, and the three are rolled by the first composite component 100 so that the three are bonded and adhered to form a composite sheet, namely the first sheet 40.

[0068] The second pole piece 50 and the first sheet 40 are then sent to the second gap between the first composite roller 210 and the second composite roller 220. Through the rolling of the first composite roller 210 and the second composite roller 220, the second pole piece 50 and the first sheet 40 are attached and bonded to form the final composite body 60.

[0069] During the above-mentioned process of laminating the second pole piece 50 and the first sheet 40 through the second composite assembly 200, the first composite roller 210 contacts the first sheet 40, the second composite roller 220 contacts the second pole piece 50, and the linear speed of the second composite roller 220 is less than the linear speed of the first composite roller 210. This can make the speed at which the second pole piece 50 enters the second gap less than the speed at which the first sheet 40 enters the second gap, thereby making the unfolded length of the second pole piece 50 in the final composite body 60 formed after the second composite assembly 200 less than the unfolded length of the first pole piece 10. The above-mentioned unfolded length refers to the length of the first pole piece 10 or the second pole piece 50 when it is stretched and laid flat on a horizontal surface. This results in the second pole piece 50 in the final composite body 60 being in a flat state, and the first pole piece 10, the first diaphragm 20 and the second diaphragm 30 being in a bent state. In this way, when the final composite body 60 is subsequently wound, the second pole piece 50 can be wound on the inside, which can reduce the risk of wrinkles in the second pole piece 50 located on the inner circle to a certain extent.

[0070] The rolling composite mechanism provided in the embodiment of the present application includes a first composite component 100 and a second composite component 200. The first composite component 100 can be used to composite the first diaphragm 20, the first electrode 10 and the second diaphragm 30 into a composite sheet body (i.e., the first sheet body 40). The second composite component 200 can be used to composite the above-mentioned composite sheet body and the second electrode 50 into a final composite body 60. Since the linear speeds of the first composite roller 210 and the second composite roller 220 in the second composite component 200 are different, the linear speed of the second composite roller 220 is less than the linear speed of the first composite roller 210. In this way, the flattened length of the second electrode 50 in the final composite body 60 formed after the composite body 200 is composited is less than the flattened length of the first electrode 10, so that the second electrode 50 in the final composite body 60 is in a flattened state and the first electrode 10 is in a bent state. In this way, when the final composite body 60 is subsequently wound, the risk of wrinkles in the second electrode 50 located in the inner circle can be reduced to a certain extent.

[0071] In some embodiments, as shown in FIG2 , a first recessed structure 310 is provided on the roller surface of the first composite roller 210. The first recessed structure 310 is used to provide a clearance space for at least a portion of the target diaphragm. The target diaphragm is the first diaphragm or the second diaphragm in the first sheet 40 that is in contact with the first composite roller 210.

[0072] The first recessed structure 310 is a structure recessed on the surface of the first composite roller 210 to avoid at least a portion of the target membrane. The first recessed structure 310 can be provided only on a portion of the surface of the first composite roller 210. Its coverage area can be smaller than the contact area between the first sheet and the first composite roller 210, or greater than or equal to the contact area between the first sheet and the first composite roller 210.

[0073] It can be understood that the above-mentioned first recessed structure 310 is used to provide avoidance space for at least part of the target diaphragm, which means that when the coverage area of ​​the first recessed structure 310 is smaller than the contact area between the first sheet and the first composite roller 210, the first recessed structure 310 is only used to avoid the part of the target diaphragm covered by the area where the first recessed structure 310 is located. When the coverage area of ​​the first recessed structure 310 is greater than or equal to the contact area between the first sheet and the first composite roller 210, the first recessed structure 310 can be used to avoid the entire contact part of the target diaphragm and the first composite roller 210.

[0074] The target diaphragm refers to the first diaphragm or the second diaphragm in the first sheet 40 that contacts the first composite roller 210, including the following two situations: First, when the first diaphragm in the first sheet is in contact with the first composite roller 210, the target diaphragm is the first diaphragm, as shown in Figure 3; Second, when the second diaphragm in the first sheet 40 is in contact with the first composite roller, the target diaphragm is the second diaphragm.

[0075] Since the diaphragm is one of the key internal components in the battery structure, the performance of the diaphragm determines the interface structure and internal resistance of the battery, and directly affects the battery's capacity, cycle and safety performance. A diaphragm with excellent performance plays an important role in improving the overall performance of the battery. The main function of the diaphragm is to separate the positive and negative electrodes of the battery to prevent the two electrodes from contacting and short-circuiting. In addition, it also has the function of allowing electrolyte ions to pass through. That is, the first diaphragm and the second diaphragm in the embodiment of the present application are mainly used to separate the first electrode and the second electrode.

[0076] In addition, when the thickness of the first diaphragm and the second diaphragm is thin, the channel for ion migration in the electrolyte will be shorter, the polarization phenomenon of the battery will be weakened to a certain extent, and the low-temperature voltage platform of the battery will be relatively higher. When the thickness of the first diaphragm and the second diaphragm is thicker, when the battery is impacted by foreign objects, it can better ensure the isolation of the internal first electrode and the second electrode. Therefore, generally the thickness of the first diaphragm and the second diaphragm needs to meet certain requirements.

[0077] In the solution provided in this embodiment, the setting of the first recessed structure 310 can, to a certain extent, reduce the magnitude of the rolling pressure exerted on the first diaphragm and the second diaphragm in the corresponding areas of the first recessed structure 310 when the first sheet passes through the second gap, so that the first diaphragm and the second diaphragm in the area are not excessively rolled and can retain a larger thickness, thereby making the spacing between the first pole piece and the second pole piece meet the preset requirements, so that the battery yield is higher.

[0078] 3 and 4 , the target membrane has a coating layer 22 . A depth h1 of the first recessed structure 310 is greater than or equal to a thickness a of the coating layer 22 .

[0079] The target diaphragm can adopt a single-layer structure, a double-layer structure, a triple-layer structure, or other multi-layer structures according to the application requirements. Compared with a single-layer structure, a double-layer structure, a triple-layer structure, or other multi-layer structure can better separate the first and second electrode sheets and facilitate the infiltration of the electrolyte.

[0080] The diaphragm generally includes a substrate 21. The substrate 21 is generally a single-layer structure, but can also be a multi-layer structure. It can be made of polyolefin materials such as polyethylene (PE) and polypropylene (PP), or other materials. The specific preparation can be based on the needs of use.

[0081] The coating 22 refers to a coating structure applied to any layer of the substrate 21. The coating 22 can be made of a ceramic material or a polymer and can be applied to the surface of the substrate 21 or disposed within the substrate 21. It should be understood that the coating 22 disposed within the substrate 21 means that the substrate 21 has a multi-layer structure, and the coating 22 is located on the surface of a layer but is not visible from the outside of the substrate 21. The coating 22 can be a single-layer structure or a multi-layer structure, and the specific choice can be made based on the actual application needs.

[0082] The coating 22 on the target diaphragm includes, but is not limited to, the following situations: First, the coating 22 is located on the surface of the target diaphragm and is in direct contact with the first composite roller; Second, the coating 22 is located inside the target diaphragm and is positioned close to the first composite roller. "Close to the first composite roller" means that the coating 22 is located between the center plane of the target diaphragm and the roller surface of the first composite roller.

[0083] When the bottom surface of the first recessed structure 310 is a curved surface parallel to the roll surface of the first composite roll, the depth h1 of the first recessed structure 310 refers to the vertical distance between the roll surface of the first composite roll and the bottom surface of the first recessed structure 310. When the bottom surface of the first recessed structure 310 is not a curved surface parallel to the roll surface of the first composite roll, the depth h1 of the first recessed structure 310 refers to the maximum vertical distance between any position on the bottom surface of the first recessed structure 310 and the roll surface of the first composite roll.

[0084] By adopting the structure provided in this embodiment, the coating 22 in the area corresponding to the target diaphragm and the first recessed structure 310 can be prevented from being squeezed and thinned, or the risk of being squeezed and thinned is low. In this way, the function of the coating 22 can be retained, or it can be less damaged, so that the distance between the first electrode and the second electrode meets the preset requirements, thereby increasing the battery yield.

[0085] In some embodiments, as shown in FIG. 2 , the first recessed structure 310 is a first annular groove disposed around the outer circumference of the first composite roller 210 .

[0086] The first recessed structure 310 adopts the configuration provided in this embodiment, which has a simple structure and is easy to prepare.

[0087] In some embodiments, a plurality of first annular grooves are provided, and the plurality of first annular grooves are spaced apart along the axial direction of the first composite roller 210 .

[0088] The interval setting means that there is a distance between two adjacent first annular grooves.

[0089] By adopting the solution provided in this embodiment, the width b1 of a single first annular groove does not need to be set too large, and the first diaphragm and the second diaphragm can effectively separate the first electrode piece 10 and the second electrode piece 50. The width b1 of a single first annular groove refers to the dimension of the first annular groove in the axial direction of the first composite roller 210.

[0090] In some embodiments, as shown in FIG. 4 , the width b1 of a single first annular groove is greater than or equal to the interval c1 between two adjacent first annular grooves.

[0091] The first annular groove has a cubic structure. The width b1 of the first annular groove refers to the dimension of the first annular groove in the axial direction of the first composite roller. The spacing c1 between the projections of two adjacent first annular grooves refers to the spacing between the two adjacent first annular grooves in the axial direction of the first composite roller.

[0092] It can be understood that, regardless of whether the first annular groove is a regular cubic structure or an irregular three-dimensional structure, the width of the first annular groove is greater than or equal to the distance c1 between the projection patterns of two adjacent first annular grooves, which means that the maximum dimension of the first annular groove in the axial direction of the first composite roller is greater than or equal to the minimum dimension of the distance between the first annular groove and the adjacent first annular grooves.

[0093] By adopting the solution provided in this embodiment, the distance between two adjacent areas with larger thickness in the first diaphragm and the second diaphragm can be smaller than the width of the corresponding areas, so that the first diaphragm and the second diaphragm can effectively separate the first electrode and the second electrode.

[0094] In some embodiments, the coverage area of ​​the first recessed structure 310 is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller 210 .

[0095] The cylindrical surface corresponding to the roller surface of the first composite roller 210 refers to the roller surface corresponding to when the first composite roller 210 is a flat roller, and is also the roller surface of the first composite roller 210 before the first recessed structure 310 is provided.

[0096] The coverage area of ​​the first concave structure 310 refers to the sum of the areas of the projection patterns of the first concave structure 310 on the cylindrical surface corresponding to the roller surface of the first composite roller 210 .

[0097] By adopting the solution provided in this embodiment, the area of ​​the region with larger thickness in the first diaphragm and the second diaphragm can account for more than 50% of the total area of ​​the corresponding surface of the diaphragm, so that the first diaphragm and the second diaphragm can play a good role in separating the first electrode and the second electrode.

[0098] In some embodiments, as shown in FIG. 6 , the first recessed structure 310 is connected to the roller surface of the first composite roller 210 via a first curved surface 410 .

[0099] The first curved surface 410 is a moving line, which is a trajectory of continuous movement in space under given conditions.

[0100] The structure provided in this embodiment can reduce the risk of wear during the contact between the first sheet 40 and the first recessed structure 310 to a certain extent.

[0101] In some embodiments, the first curved surface 410 is a chamfered surface.

[0102] The chamfered surface is generally a rounded surface, which can be obtained by chamfering the connection area between the first recessed structure 310 and the roller surface. This structure is easy to manufacture.

[0103] In some embodiments, as shown in FIG5 , a second recessed structure 320 is provided on the roller surface of the second composite roller 220. The second recessed structure 320 is used to provide a clearance space for at least a portion of the second pole piece.

[0104] The second recessed structure 320 is a structure recessed on the surface of the second composite roller 220 to avoid at least a portion of the target diaphragm. The second recessed structure 320 can be provided only on a portion of the surface of the second composite roller 220. Its coverage area can be smaller than the contact area between the second electrode piece and the second composite roller 220, or greater than or equal to the contact area between the second electrode piece and the second composite roller 220.

[0105] It can be understood that the above-mentioned second recessed structure 320 is used to provide avoidance space for at least part of the second electrode piece, which means that when the coverage area of ​​the second recessed structure 320 on the second composite roller is smaller than the contact area between the second electrode piece and the second composite roller, the second recessed structure 320 is only used to avoid the part of the second electrode piece covered by the area where the second recessed structure 320 is located; when the coverage area of ​​the second recessed structure 320 is greater than or equal to the contact area between the second electrode piece and the second composite roller, the second recessed structure 320 can be used to avoid the entire contact part between the second electrode piece and the second composite roller.

[0106] As mentioned above, the first diaphragm and the second diaphragm are mainly used to separate the first electrode piece from the second electrode piece; generally, the thickness of the first diaphragm and the second diaphragm needs to meet certain requirements.

[0107] In the solution provided in this embodiment, the setting of the second recessed structure 320 can, to a certain extent, reduce the magnitude of the rolling pressure exerted on the first diaphragm and the second diaphragm in the corresponding areas of the second recessed structure 320 when the second electrode sheet and the first sheet pass through the second gap, so that the first diaphragm and the second diaphragm in the area are not excessively rolled and a larger thickness is retained, thereby making the spacing between the first electrode sheet and the second electrode sheet meet the preset requirements, so that the battery yield is higher.

[0108] In some embodiments, the second recessed structure 320 is a second annular groove disposed around the outer circumference of the second composite roller 220 .

[0109] The second recessed structure 320 adopts the configuration provided in this embodiment, which has a simple structure and is easy to prepare.

[0110] In some embodiments, a plurality of second annular grooves are provided on the second composite roller 220. All the second annular grooves are spaced apart along the axial direction of the second composite roller 220.

[0111] By adopting the solution provided in this embodiment, the width b2 of the single second annular groove does not need to be set too large, and the first diaphragm and the second diaphragm can effectively separate the first pole piece 10 and the second pole piece 50.

[0112] In some embodiments, as shown in FIG. 6 , the second recessed structure 320 is connected to the roller surface of the first composite roller 210 via a second curved surface 420 .

[0113] The second curved surface 420 is a moving line, which is a trajectory of continuous movement in space under given conditions.

[0114] The structure provided in this embodiment can reduce, to a certain extent, the risk of wear occurring during the contact between the second pole piece and the second recessed structure 320 .

[0115] In some embodiments, the second curved surface 420 is a chamfered surface.

[0116] The chamfered surface is generally a rounded surface, which can be obtained by chamfering the connection area between the second recessed structure 320 and the roller surface. This structure is easy to prepare.

[0117] In some embodiments, the first recessed structure 310 and the second recessed structure 320 are staggered.

[0118] The staggered arrangement means that the positions of the first recessed structure 310 and the second recessed structure 320 do not correspond to each other, and their projection patterns on the same horizontal plane at least partially do not overlap.

[0119] In this way, the sizes of the first recessed structure 310 and the second recessed structure 320 can be set smaller, so that the final composite body can meet the preset requirements and have less impact on the structural stability of the first composite roller and the second composite roller.

[0120] In some embodiments, a plurality of first concave structures 310 and a plurality of second concave structures 320 are provided. All first concave structures 310 are spaced apart along the axial direction of the first composite roller 210 , and all second concave structures 320 are spaced apart along the axial direction of the second composite roller 220 .

[0121] In this embodiment, the arrangement of the first recessed structure 310 and the second recessed structure 320 includes but is not limited to the following situations:

[0122] The first type is that the projection pattern of any first recessed structure 310 on the roller surface of the second composite roller 220 has no overlapping area with any second recessed structure 320, that is, the projection patterns of the first recessed structure 310 and the second recessed structure 320 on the same horizontal plane have no overlapping area; the second type is that the projection pattern of at least one first recessed structure 310 on the roller surface of the second composite roller 220 has a certain overlapping area with at least one second recessed structure 320, that is, the projection patterns of the first recessed structure 310 and the second recessed structure 320 on the same horizontal plane have an overlapping area, and the overlapping area is a part of the projection pattern of the first recessed structure 310.

[0123] In this way, the sizes of the first recessed structure 310 and the second recessed structure 320 can be made smaller, and while the final composite body 60 meets the preset requirements, the structural stability of the first composite roller 210 and the second composite roller 220 can be less affected.

[0124] In some embodiments, the projection pattern of at least one first recessed structure 310 on the roller surface of the second composite roller 220 is located between two second recessed structures 320 .

[0125] The projection pattern of at least one first recessed structure 310 on the roller surface of the second composite roller 220 is located between the two second recessed structures 320, which means that the projection pattern of at least one first recessed structure 310 on the roller surface of the second composite roller 220 falls within the gap between two adjacent second recessed structures 320 and has no overlapping area with any second recessed structure 320.

[0126] In this way, compared with the projection patterns of all the first recessed structures 310 on the roller surface of the second composite roller 220 having overlapping areas with the second recessed structures 320, the size of the first recessed structures 310 and / or the second recessed structures 320 can be further reduced, and the adverse effects of the settings of the first recessed structures 310 and the second recessed structures 320 on the structural stability of the first composite roller 210 and the second composite roller 220 can be reduced.

[0127] In some embodiments, the projection pattern of any first recessed structure 310 on the roller surface of the second composite roller 220 is located between two second recessed structures 320 .

[0128] The projection pattern of any first recessed structure 310 on the roller surface of the second composite roller 220 being located between two second recessed structures 320 means that the projection pattern of each first recessed structure 310 on the roller surface of the second composite roller 220 falls within the interval between two adjacent second recessed structures 320, i.e., the projection pattern of any first recessed structure 310 on the roller surface of the second composite roller 220 does not overlap with any second recessed structure 320. In other words, the projection patterns of the first recessed structures 310 and the second recessed structures 320 on the same horizontal plane are arranged alternately, i.e., the projection patterns of the first recessed structure 310 and the second recessed structure 320 on the same horizontal plane are arranged in the order of projection pattern of the first recessed structure 310, projection pattern of the second recessed structure 320, projection pattern of the first recessed structure 310, projection pattern of the second recessed structure 320, and so on.

[0129] In this way, compared with the overlapping area between the projection pattern of at least part of the first recessed structure 310 on the roller surface of the second composite roller 220 and the second recessed structure 320, the size of the first recessed structure 310 and / or the second recessed structure 320 can be further reduced, and the adverse effects of the setting of the first recessed structure 310 and the second recessed structure 320 on the structural stability of the first composite roller 210 and the second composite roller 220 can be reduced.

[0130] In some embodiments, a width b2 of at least one second recess structure 320 is greater than or equal to a distance c2 between the projection pattern of the second recess structure 320 and an adjacent first recess structure 310 .

[0131] The second recessed structure 320 is a cubic structure. The width b2 of the second recessed structure 320 refers to the dimension of the second recessed structure 320 in the axial direction of the second composite roller 220. The spacing c2 between the second recessed structure 320 and the projection of the adjacent first recessed structure 310 refers to the dimension of the spacing between the second recessed structure 320 and the projection of the adjacent first recessed structure 310 in the axial direction of the second composite roller 220.

[0132] It can be understood that regardless of whether the second recessed structure 320 is a regular cubic structure or an irregular cubic structure, the width of the second recessed structure 320 is greater than or equal to the distance c2 between the projection pattern of the second recessed structure 320 and the adjacent first recessed structure 310, which means that the maximum dimension of the second recessed structure 320 in the axial direction of the second composite roller 220 is greater than or equal to the minimum dimension of the distance between the projection pattern of the second recessed structure 320 and the adjacent first recessed structure 310.

[0133] By adopting the solution provided in this embodiment, the interval between two adjacent areas with larger thickness in the first diaphragm 20 and the second diaphragm 30 can be smaller than the width of the corresponding areas, so that the areas with larger thickness in the first diaphragm 20 and the second diaphragm 30 can play a good role in separating the first electrode 10 and the second electrode 50.

[0134] In some embodiments, the total coverage area of ​​all the recessed structures is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller 210 or the second composite roller 220 .

[0135] The sum of the coverage areas of all the recessed structures is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller 210 or the second composite roller 220, including the following situations: First, the sum of the areas of the projection patterns of all the first recessed structures 310 on the roller surface of the second composite roller 220 and the sum of the coverage areas of all the second recessed structures 320 is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the second composite roller 220; Second, the sum of the areas of the projection patterns of all the second recessed structures 320 on the roller surface of the first composite roller 210 and the sum of the coverage areas of all the first recessed structures 310 is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller 210. It is understood that the cylindrical surface corresponding to the roller surface of the first composite roller 210 refers to the cylindrical roller surface of the first composite roller 210 before the first recessed structure 310 is provided, and the cylindrical surface corresponding to the roller surface of the second composite roller 220 refers to the cylindrical roller surface of the second composite roller 220 before the second recessed structure 320 is provided. The coverage area of ​​the first recessed structure 310 refers to the area of ​​the projection of the first recessed structure 310 on the cylindrical surface corresponding to the roller surface of the first composite roller 210, and the coverage area of ​​the second recessed structure 320 refers to the area of ​​the projection of the second recessed structure 320 on the cylindrical surface corresponding to the roller surface of the second composite roller 220.

[0136] By adopting the solution provided in this embodiment, the area of ​​the region with greater thickness in the first diaphragm 20 can account for more than 50% of the total area of ​​the same surface of the first diaphragm 20, and the area of ​​the region with greater thickness in the second diaphragm 30 can account for more than 50% of the total area of ​​the same surface of the second diaphragm 30, so that the region with greater thickness in the first diaphragm 20 and the second diaphragm 30 can play a good role in separating the first electrode 10 and the second electrode 50.

[0137] The linear velocity of the second composite roller 220 being slower than the linear velocity of the first composite roller 210 can be achieved in various ways. For example, in some embodiments, the outer diameter of the first composite roller 210 is different from the outer diameter of the second composite roller 220. In other embodiments, the first composite roller 210 and the second composite roller 220 have different rotational speeds. In other embodiments, the first composite roller 210 and the second composite roller 220 may have different outer diameters and rotational speeds, and the specific method can be determined based on actual use.

[0138] The outer diameter of the first composite roller 210 refers to the diameter of the cylindrical surface corresponding to the roller surface of the first composite roller 210. The outer diameter of the second composite roller 220 refers to the diameter of the cylindrical surface corresponding to the roller surface of the second composite roller 220.

[0139] When the outer diameter of the first composite roll 210 is different from the outer diameter of the second composite roll 220, the outer diameter of the first composite roll 210 may be larger or smaller than the outer diameter of the second composite roll 220. It is understood that when the outer diameter of the first composite roll 210 is larger than the outer diameter of the second composite roll 220, the rotational speed of the first composite roll 210 may be set to be the same as the rotational speed of the second composite roll 220, thereby making the linear speed of the second composite roll 220 slower than that of the first composite roll 210. When the outer diameter of the first composite roll 210 is smaller than the outer diameter of the second composite roll 220, the rotational speed of the first composite roll 210 needs to be set to be faster than the rotational speed of the second composite roll 220, thereby making the linear speed of the second composite roll 220 slower than that of the first composite roll 210.

[0140] When the rotational speeds of the first composite roller 210 and the second composite roller 220 are different, the rotational speed of the first composite roller 210 may be greater than or less than that of the second composite roller 220. It is understood that when the rotational speed of the first composite roller 210 is greater than that of the second composite roller 220, the outer diameter of the first composite roller 210 may be set to be the same as that of the second composite roller 220, thereby making the linear speed of the second composite roller 220 less than that of the first composite roller 210. When the rotational speed of the first composite roller 210 is less than that of the second composite roller 220, the outer diameter of the first composite roller 210 needs to be set to be greater than that of the second composite roller 220, thereby making the linear speed of the second composite roller 220 less than that of the first composite roller 210.

[0141] Regardless of which of the above methods is adopted, it is convenient to design so that the linear speed of the second composite roller 220 is lower than the linear speed of the first composite roller 210 .

[0142] In some embodiments, as shown in FIG7 , a plurality of first composite rollers 210 are provided. All first composite rollers 210 have the same outer diameter and rotational speed. All first composite rollers 210 are arranged around the second composite roller 220. Furthermore, the gaps between any two first composite rollers 210 and second composite rollers 220 are the same.

[0143] By adopting the solution provided in this embodiment, the first plate 40 and the second pole piece 50 can achieve good composite effect and conveying effect when passing through the second gap.

[0144] In some embodiments, as shown in FIG. 1 and FIG. 7 , the first composite assembly 100 includes a third composite roller 110 and a fourth composite roller 120 that are spaced apart, and a first gap is defined between the third composite roller 110 and the fourth composite roller 120 .

[0145] The third composite roller 110 can be a flat roller with a smooth surface, or a roller with a convex structure or a concave structure on the surface, which can be determined according to the specific use requirements. The number of the third composite roller 110 can be one or more, which can be determined according to the specific use requirements.

[0146] The fourth composite roller 120 can be a flat roller with a smooth surface, or a roller with a convex structure or a concave structure on the surface, which can be determined according to the specific use requirements. The number of the fourth composite roller 120 can be one or more, which can be determined according to the specific use requirements.

[0147] By adopting the solution provided in this embodiment, the first composite component 100 has a simple structure and is easy to install and use.

[0148] In some embodiments, as shown in Figures 1 and 7, the roll-to-lamination mechanism further includes a first guide roller 500, a second guide roller 600, and a third guide roller 700 located upstream of the first composite assembly 100. The first guide roller 500 is used to contact the first diaphragm 20 and guide the first diaphragm 20 to move toward the side where the first composite assembly 100 is located. The second guide roller 600 is used to contact the second diaphragm 30 and guide the second diaphragm 30 to move toward the side where the first composite assembly 100 is located. The third guide roller 700 is used to contact the first pole piece 10 and guide the first pole piece 10 to move toward the side where the first composite assembly 100 is located.

[0149] The first guide roller 500, the second guide roller 600, and the third guide roller 700 can be smooth flat rollers or rollers with raised or recessed surfaces, depending on the specific needs. The number of first guide rollers 500, second guide rollers 600, and third guide rollers 700 can be one or more, depending on the specific needs. The structures of the first guide roller 500, second guide roller 600, and third guide roller 700 can be the same or different.

[0150] The roller-pressing composite mechanism adopts the structure provided by this embodiment, which has more complete functions and is more convenient to use.

[0151] According to some embodiments of the present application, embodiments of the present application further provide a winding device, which includes a roll-combining mechanism according to any of the above schemes. As mentioned above, in addition to the roll-combining mechanism, the winding device may also include a winding needle or other device located downstream of the roll-combining mechanism, the specific details of which may be determined based on usage needs. The winding device provided in the embodiments of the present application, including the roll-combining mechanism according to any of the above schemes, can reduce the risk of wrinkles in the second pole piece located on the inner ring to a certain extent.

[0152] According to some embodiments of the present application, the present application also provides a winding production line, including the winding equipment of any of the above solutions. As mentioned above, in addition to the winding equipment, the winding production line may also include a feeding mechanism located upstream of the roller-pressing lamination mechanism, or other equipment, which can be determined according to the specific needs of use. The winding production line provided in the embodiment of the present application, including the winding equipment of any of the above solutions, can reduce the risk of wrinkles in the second pole piece located on the inner ring to a certain extent.

[0153] As shown in Figures 1 to 7, according to some embodiments of the present application, a roll-to-lamination mechanism is provided. The roll-to-lamination mechanism includes a first composite assembly 100 and a second composite assembly 200 arranged sequentially along the conveying direction of the first electrode sheet 10. The first composite assembly 100 has a first gap for the passage of the first diaphragm 20, the first electrode sheet 10, and the second diaphragm 30. The second composite assembly 200 includes a first composite roller 210 and a second composite roller 220 arranged at intervals. The first composite roller 210 is configured to engage in rolling frictional contact with the first sheet 40. The second composite roller 220 is configured to engage in rolling frictional contact with the second electrode sheet 50. A second gap is defined between the second composite roller 220 and the first composite roller 210 for the passage of the first sheet 40 and the second electrode sheet 50. The linear velocity of the second composite roller 220 is less than that of the first composite roller 210. The first sheet 40 is the composite sheet formed after the first diaphragm 20, the first electrode sheet 10, and the second diaphragm 30 pass through the first composite assembly 100.

[0154] In some embodiments, a first recessed structure 310 is provided on the surface of the first composite roller 210. The first recessed structure 310 is configured to provide clearance for at least a portion of the target diaphragm. The target diaphragm is the first diaphragm 20 or the second diaphragm 30 in the first sheet 40 that contacts the first composite roller 210. The target diaphragm has a coating 22, and the depth of the first recessed structure 310 is greater than or equal to the thickness of the coating 22.

[0155] The first recessed structure 310 is a first annular groove disposed around the outer circumference of the first composite roller 210. Multiple first annular grooves are provided, spaced apart along the axial direction of the first composite roller 210. The width b1 of a single first annular groove is greater than or equal to the spacing c1 between two adjacent first annular grooves.

[0156] The coverage area of ​​the first concave structure 310 is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller 210. The first concave structure 310 is connected to the roller surface of the first composite roller 210 through the first curved surface 410. The first curved surface 410 is a chamfered surface.

[0157] In other embodiments, a first recessed structure 310 is provided on the surface of the first composite roller 210. The first recessed structure 310 is configured to provide clearance for at least a portion of the target diaphragm. The target diaphragm is the first diaphragm 20 or the second diaphragm 30 in the first sheet 40 that contacts the first composite roller 210. The target diaphragm has a coating 22, and the depth of the first recessed structure 310 is greater than or equal to the thickness of the coating 22.

[0158] The first recessed structure 310 is a first annular groove formed on the outer circumference of the first composite roller 210. A second recessed structure 320 is provided on the roller surface of the second composite roller 220. The second recessed structure 320 is used to provide a clearance space for at least a portion of the second pole piece 50. The second recessed structure 320 is a second annular groove formed on the outer circumference of the second composite roller 220.

[0159] The second composite roller 220 is provided with a plurality of second annular grooves, all of which are spaced apart along the axial direction of the second composite roller 220. The second recessed structure 320 is connected to the roller surface of the second composite roller 220 via a second curved surface 420. The second curved surface 420 is a chamfered surface.

[0160] Multiple first and second recessed structures 310, 320 are provided. All first recessed structures 310 are spaced apart along the axial direction of the first composite roll 210, and all second recessed structures 320 are spaced apart along the axial direction of the second composite roll 220. The projection of any first recessed structure 310 on the surface of the second composite roll 220 is located between two second recessed structures 320. The width of any second recessed structure 320 is greater than or equal to the distance between the projection of that second recessed structure 320 and the adjacent first recessed structure 310. The total coverage area of ​​all recessed structures is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the surface of the first composite roll 210 or the second composite roll 220.

[0161] The outer diameter of the first composite roller 210 is different from the outer diameter of the second composite roller 220 , or the rotation speeds of the first composite roller 210 and the second composite roller 220 are different.

[0162] There are multiple first composite rollers 210. All first composite rollers 210 have the same outer diameter and rotation speed. All first composite rollers 210 are arranged around the second composite roller 220. The gaps between any two first composite rollers 210 and second composite rollers 220 are the same.

[0163] The first composite assembly 100 includes a third composite roll 110 and a fourth composite roll 120 that are spaced apart from each other. A first gap is defined between the third composite roll 110 and the fourth composite roll 120.

[0164] The roll-to-lamination mechanism also includes a first guide roller 500, a second guide roller 600, and a third guide roller 700 located upstream of the first composite assembly 100. The first guide roller 500 is configured to contact the first diaphragm 20 and guide the first diaphragm 20 toward the side of the first composite assembly 100. The second guide roller 600 is configured to contact the second diaphragm 30 and guide the second diaphragm 30 toward the side of the first composite assembly 100. The third guide roller 700 is configured to contact the first pole piece 10 and guide the first pole piece 10 toward the side of the first composite assembly 100.

[0165] By using the roller-pressing laminating mechanism provided in this embodiment, the first pole piece 10 (single-layer pole piece) and the two-layer diaphragm can be laminated first, and then laminated with the second pole piece 50 through the first laminating roller 210 and the second laminating roller 220 with a linear speed difference.

[0166] At least one of the first and second composite rollers 210 and 220 is grooved to avoid air gaps, preserving the separator's gap-forming function. This gap-forming function allows the separator to separate the first and second electrode pieces 10 and 50, i.e., the cathode and anode, creating a gap between them. The separator typically has a coating 22, which can be made of a PCS (polycarbosilane) polymer.

[0167] The above groove is parallel to the end face of the composite roller, the depth must exceed the height of the PCS, and the edge of the groove needs to be chamfered to avoid scratching the pole piece.

[0168] In the related art, under normal circumstances, before the cathode electrode, anode electrode and two-layer separator are four-in-one composited, the cathode and anode electrodes are of equal length. After entering the winding needle, the inner electrode is shorter than the outer electrode, which poses a risk of wrinkling. However, by adopting the roller-pressing composite mechanism provided in this embodiment, the two-layer separator and the single-layer electrode (i.e., the first electrode 10) can be composited by roller welding to form a three-in-one electrode-separator tape form. After the electrode-separator is three-in-one, it is then composited with the single-layer electrode (i.e., the second electrode 50) through the first composite roller 210 and the second composite roller 220 with a linear speed difference to form a four-in-one electrode-separator tape form, which is then wound into a bare battery cell. The length of the inner and outer electrode sheets is fine-tuned by the linear speed difference between the composite rollers to avoid wrinkling of the inner electrode sheet after composited. The composite roller is used to make grooves to avoid air gaps, thereby retaining the gap-making function of the separator to the greatest extent. The linear speed difference of the composite rollers can be achieved by having the first composite roller 210 and the second composite roller 220 have the same angular speed but different diameters, or having the same diameters but different angular speeds.

[0169] In some embodiments, the first electrode piece 10 may be an anode electrode piece, and the second electrode piece 50 may be a cathode electrode piece. That is, in the above process, the two layers of the separator may first be combined with the anode electrode piece, and then, after the anode electrode piece and the separator are combined into one, they are combined with the cathode electrode piece. In other embodiments, the first electrode piece 10 may be a cathode electrode piece, and the second electrode piece 50 may be an anode electrode piece. That is, in the above process, the two layers of the separator may first be combined with the cathode electrode piece, and then, after the cathode electrode piece and the separator are combined into one, they are combined with the anode electrode piece.

[0170] In some embodiments, there may be two first composite rollers 210. In this case, the above process is performed as follows: the two layers of diaphragm are first composited with the first electrode piece 10, the first electrode piece 10 and the diaphragm are composited into three layers, and then composited with the second electrode piece 50. The electrode piece and diaphragm are composited into a winding needle for winding. The four layers of electrode pieces / diaphragms are composited by three composite rollers (two first composite rollers 210 and one second composite roller 220), and the composite length of the inner ring electrode piece is fine-tuned to avoid wrinkling of the inner ring electrode piece after pre-stressing during winding. Among them, the angular velocity, diameter, roller structure, etc. of the two first composite rollers 210 are the same. The linear speed difference of the composite rollers can be achieved by the second composite roller 220 having the same angular velocity and different diameter as the two first composite rollers 210, the second composite roller 220 having the same diameter and different angular velocity as the two first composite rollers 210, etc.

[0171] The roll-pressing lamination mechanism provided in this embodiment is suitable for the winding process of bare battery cells. It can improve the wrinkling problem of the four-in-one composite of cathode and anode electrodes and separators, and can also retain the gap-forming function of the separator to a greater extent. The gap-forming function refers to the separator's ability to separate the first electrode piece 10 from the second electrode piece 50, that is, to separate the cathode electrode piece from the anode electrode piece, so that there is a gap between the two electrode pieces.

[0172] The roll-pressing composite mechanism provided in this embodiment can reduce, to a certain extent, the risk of wrinkles on the inner-circle electrode during the winding process, thereby improving the yield of the wound electrode assembly.

[0173] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A roller-pressing composite mechanism, characterized in that: The method comprises a first composite assembly and a second composite assembly which are sequentially arranged along a conveying direction of a first electrode piece, wherein the first composite assembly has a first gap for allowing a first diaphragm, a first electrode piece and a second diaphragm to pass through, and the second composite assembly comprises a first composite roller and a second composite roller which are arranged at intervals; The first composite roller is used for rolling friction contact with the first sheet; the first sheet is a composite sheet formed by the first diaphragm, the first pole piece and the second diaphragm passing through the first composite assembly; The second composite roller is used for rolling friction contact with the second pole piece, and a second gap is provided between the second composite roller and the first composite roller for the first sheet body and the second pole piece to pass through, and the first sheet body and the second pole piece form a final composite body after passing through the second composite assembly; The linear speed of the second composite roller is lower than the linear speed of the first composite roller.

2. The roll-combination mechanism according to claim 1, characterized in that: A first recessed structure is provided on the roller surface of the first composite roller, and the first recessed structure is used to provide an escape space for at least part of the target diaphragm; wherein the target diaphragm refers to the first diaphragm or the second diaphragm in the first sheet body that is in contact with the first composite roller.

3. The roll-combination mechanism according to claim 2, characterized in that: The target membrane has a coating layer, and the depth of the first recessed structure is greater than or equal to the thickness of the coating layer.

4. The roll-combination mechanism according to claim 2 or 3, characterized in that: The first recessed structure is a first annular groove arranged around the outer circumferential surface of the first composite roller.

5. The roll-combination mechanism according to claim 4, characterized in that: A plurality of the first annular grooves are provided, and the plurality of the first annular grooves are spaced apart along the axial direction of the first composite roller.

6. The roll-combination mechanism according to claim 5, characterized in that: The width of a single first annular groove is greater than or equal to the distance between two adjacent first annular grooves.

7. The roller-combining mechanism according to any one of claims 2 to 6, characterized in that: The coverage area of ​​the first recessed structure is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller.

8. The roller-combining mechanism according to any one of claims 2 to 7, characterized in that: The first recessed structure is connected to the roller surface of the first composite roller via a first curved surface.

9. The roll-combination mechanism according to claim 8, characterized in that: The first curved surface is a chamfered surface.

10. The roller-combining mechanism according to any one of claims 2 to 9, characterized in that: A second recessed structure is disposed on the roller surface of the second composite roller, and the second recessed structure is used to provide an escape space for at least a portion of the second pole piece.

11. The roll-combination mechanism according to claim 10, characterized in that: The second recessed structure is a second annular groove arranged around the outer circumferential surface of the second composite roller.

12. The roll-combination mechanism according to claim 11, characterized in that: The second composite roller is provided with a plurality of second annular grooves, and all the second annular grooves are arranged at intervals along the axial direction of the second composite roller.

13. The roller-combining mechanism according to any one of claims 10 to 12, characterized in that: The second recessed structure is connected to the roller surface of the second composite roller via a second curved surface.

14. The roll-combination mechanism according to claim 13, characterized in that: The second curved surface is a chamfered surface.

15. The roller-combining mechanism according to any one of claims 10 to 14, characterized in that: The first recessed structure and the second recessed structure are staggered.

16. The roll-combination mechanism according to claim 15, characterized in that: There are a plurality of the first recessed structures and a plurality of the second recessed structures respectively, all of the first recessed structures are spaced apart along the axial direction of the first composite roller, and all of the second recessed structures are spaced apart along the axial direction of the second composite roller.

17. The roll-combination mechanism according to claim 16, characterized in that: A projection pattern of at least one of the first recessed structures on the roller surface of the second composite roller is located between two of the second recessed structures.

18. The roll-combination mechanism according to claim 16, characterized in that: The projection pattern of any one of the first recessed structures on the roller surface of the second composite roller is located between two of the second recessed structures.

19. The roll-combination mechanism according to claim 18, characterized in that: A width of at least one of the second recessed structures is greater than or equal to a distance between the projection patterns of the second recessed structure and an adjacent first recessed structure.

20. The roller-combining mechanism according to any one of claims 15 to 19, characterized in that: The sum of the coverage areas of all the recessed structures is greater than or equal to 50% of the area of ​​the cylindrical surface corresponding to the roller surface of the first composite roller or the second composite roller.

21. The roller-combining mechanism according to any one of claims 1 to 20, characterized in that: The outer diameter of the first composite roller is different from the outer diameter of the second composite roller.

22. The roller-combining mechanism according to any one of claims 1 to 21, characterized in that: The first composite roller and the second composite roller have different rotation speeds.

23. The roller-combining mechanism according to any one of claims 1 to 22, characterized in that: There are multiple first composite rollers, all of which have the same outer diameter and rotation speed, are arranged around the second composite roller, and the gaps between any two of the first composite rollers and the second composite rollers are the same.

24. The roller-compression laminating mechanism according to any one of claims 1 to 23, characterized in that: The first composite assembly includes a third composite roller and a fourth composite roller which are arranged at an interval, and the first gap is formed between the third composite roller and the fourth composite roller.

25. The roller-combining mechanism according to any one of claims 1 to 24, characterized in that: The rolling composite mechanism also includes a first guide roller, a second guide roller and a third guide roller located upstream of the first composite component, the first guide roller is used to contact the first diaphragm and guide the first diaphragm to move toward the side where the first composite component is located, the second guide roller is used to contact the second diaphragm and guide the second diaphragm to move toward the side where the first composite component is located, and the third guide roller is used to contact the first pole piece and guide the first pole piece to move toward the side where the first composite component is located.

26. A winding device, characterized in that: It comprises the roller-compounding mechanism described in any one of claims 1-25.

27. A winding production line, characterized in that: Comprising the winding device as claimed in claim 26.

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