A film lamination apparatus and a lamination method
By winding a second film onto an unwinding device and pressing it in a film lamination equipment, the problem of wrinkling during film lamination is solved, improving the quality and production efficiency of the composite film. This method is suitable for laminating lithium-ion battery separators.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QINGTAO (KUNSHAN) ENERGY DEV CO LTD
- Filing Date
- 2023-03-17
- Publication Date
- 2026-06-02
AI Technical Summary
During the thin film lamination process, the film is prone to wrinkling, which leads to a decrease in the quality of the composite film and a reduction in production efficiency. In particular, with the trend of lightweighting lithium-ion battery separators, the film is prone to breakage during the lamination process.
Design a film laminating device that avoids film wrinkling by winding a second film onto a second unwinding device and pressing it during the unwinding process. The second unwinding device and the laminating device abut against each other and rotate at the same angular velocity to ensure uniform pressure on the film surface and eliminate the need for conveying rollers.
It effectively avoids film wrinkling, improves the quality and production efficiency of composite films, reduces film conveying defects during the lamination process, and ensures the integrity of composite films.
Smart Images
Figure CN116353044B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of thin film composite technology, and in particular to a thin film composite device and composite method. Background Technology
[0002] As one of the four key components of a lithium-ion battery, the separator has a significant impact on battery performance. The quality of the separator largely determines the performance of the lithium-ion battery. However, traditional polyolefin separators composed of a single PP, PE, or both can no longer meet the performance requirements of current lithium-ion battery technology due to their limited performance characteristics. Therefore, composite separator technology has emerged, including the composite of ceramic layers with the separator substrate layer and the composite of polymer layers with the separator substrate layer. Taking ceramic composite separators as an example, in order to coat the ceramic layer onto the separator substrate, the separator needs to have certain mechanical support properties. However, with the increasing demand for lightweight lithium-ion batteries, ultra-thin separators have become a technological trend. Therefore, researching how to prepare ultra-thin composite separators is essential.
[0003] The applicant's previous research used a self-supporting membrane as a support membrane, and then composited the sub-support membrane with the separator substrate. However, while existing composite devices can combine two or more membranes to form a composite membrane, thus improving the performance of the original membrane, the separator is relatively thin, and coating it with a solid electrolyte layer can cause the separator to rupture. Composite membranes formed by combining a self-supporting membrane and a separator have higher mechanical strength, and coating them with a solid electrolyte layer is less likely to cause rupture.
[0004] Figure 1 This is a schematic diagram of the structure of a thin film composite device in the prior art, such as... Figure 1 As shown, the lamination process of separator 50 and self-supporting membrane 60 is as follows: the first unwinding roller 10 of the thin film laminating equipment releases separator 50, the second unwinding roller 20 releases self-supporting membrane 60, separator 50 and self-supporting membrane 60 are conveyed and laminated at laminating roller 30, and then wound up by winding roller 40 to obtain composite membrane 70 composed of separator 50 and self-supporting membrane 60. However, as mentioned above, with the development of battery portability, separators and related auxiliary materials tend to be thinner and lighter, which leads to separators being prone to wrinkling and cracking during lamination calendering and conveyor belt operation. Once the separator wrinkles, it greatly affects the lamination effect, and significant wrinkling can even lead to product scrap, greatly affecting production efficiency. At the same time, the same problem also occurs in the lamination scenarios of other thin film products.
[0005] Therefore, there is an urgent need for a film lamination device and method to solve the problem of wrinkling of films during the lamination process. Summary of the Invention
[0006] This application provides a thin film lamination apparatus and a lamination method, which can solve the problem of wrinkling of thin films during the lamination process.
[0007] To solve one or more of the above-mentioned technical problems, the technical solution adopted in this application is:
[0008] In a first aspect, this application provides a film laminating device, which includes a first unwinding device, a second unwinding device, a laminating device, and a winding device.
[0009] The first unwinding device is used to unwind the first film;
[0010] The second unwinding device is used to unwind the second film;
[0011] The second unwinding device abuts against the composite device, and the first film and the second film are laminated between the second unwinding device and the composite device to form a composite film;
[0012] The second unwinding device is disposed between the unwinding device and the winding device. The second unwinding device is used to unwind the second film and press the first film and the second film together.
[0013] The winding device is used to wind up the composite film.
[0014] The second film is wound onto the second unwinding device.
[0015] Furthermore, the second unwinding device and the composite device rotate at the same angular velocity.
[0016] Furthermore, the second unwinding device moves in a direction approaching or away from the composite device as the thickness of the second film wound on the second unwinding device changes.
[0017] Furthermore, the first film includes a first film body and an adhesive layer covering the first film body, the adhesive layer being on the side close to the second film.
[0018] Furthermore, the first film body comprises polyethylene terephthalate or polypropylene;
[0019] And / or,
[0020] The adhesive layer includes a fluorinated adhesive layer.
[0021] Furthermore, the second film comprises a polyethylene terephthalate film or a polypropylene film, and the thickness of the second film is 1-10 micrometers;
[0022] And / or,
[0023] The thickness of the first film is 40-60 micrometers.
[0024] Furthermore, the first unwinding device includes an unwinding roller;
[0025] And / or,
[0026] The second unwinding device includes a pressure roller;
[0027] And / or,
[0028] The composite device includes a composite roller;
[0029] And / or,
[0030] The winding device includes a winding roller.
[0031] Furthermore, the film laminating equipment also includes a driving device for driving the second unwinding device to move closer to or away from the laminating device.
[0032] Furthermore, the drive device includes a cylinder.
[0033] Secondly, this application also provides a thin film composite method, the composite method comprising:
[0034] The first film is unwound using the first unwinding device;
[0035] A second film is unwound using a second unwinding device and then pressed together with a composite device by the second unwinding device to form a composite film by combining the first film and the second film.
[0036] The composite film is wound up using a winding device.
[0037] According to the specific embodiments provided in this application, the following technical effects are disclosed:
[0038] This application provides a film lamination device and a lamination method that integrates the unwinding and lamination of the second film. By winding the second film onto a second unwinding device, the second unwinding device simultaneously unwinds and presses the second film wound on it to prevent wrinkling of the second film. The second film does not pass through the conveyor roller before being laminated with the first film, thereby reducing the poor conveyor belt conditions caused by the second film being suspended, which would affect the quality of the composite film formed by the lamination of the second film and the first film.
[0039] Furthermore, the laminating device and the second unwinding device are arranged in contact with each other, and the second unwinding device and the laminating device rotate towards each other with equal angular velocities. This arrangement helps to ensure uniform surface pressure on the first film and the second film, thereby preventing the second unwinding device and the laminating device from intersecting and causing the film to wrinkle.
[0040] Of course, any product implementing this application does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description
[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0042] Figure 1 This is a schematic diagram of the structure of a thin film composite device in the prior art;
[0043] Figure 2 This is a schematic diagram of the structure of the thin film composite device provided in the embodiments of this application;
[0044] Figure 3 A flowchart of a thin film composite method provided in an embodiment of this application. Detailed Implementation
[0045] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art are within the scope of protection of this application.
[0046] As described in the background section, the diaphragm is relatively thin, and coating it with a solid electrolyte layer can cause it to rupture. Composite membranes formed by combining a self-supporting membrane and a diaphragm have higher mechanical strength, and coating them with a solid electrolyte layer is less likely to cause rupture. However, the diaphragm is thin and prone to wrinkling during transport. Wrinkled diaphragms and self-supporting membranes, when combined at the composite roller, can negatively impact the quality of the composite membrane.
[0047] To address this issue, this application provides a thin-film lamination apparatus and method. The thin film is formed by laminating a first thin film and a second thin film. The first thin film includes a first thin film body and an adhesive layer disposed between the first and second thin films. This application avoids wrinkling of the diaphragm by winding it onto a second unwinding device, which simultaneously unwinds and presses the diaphragm while it is wound on the device, thus preventing wrinkles from affecting the quality of the composite film formed by laminating the diaphragm and the self-supporting membrane. The thin-film lamination apparatus and method provided in this embodiment are used for laminating diaphragms and self-supporting membranes, but are not limited to this; they can also be used to laminate other different types of thin films.
[0048] Figure 2 This is a schematic diagram of the structure of the thin film composite device provided in an embodiment of this application. Figure 2As shown, the film laminating equipment generally includes: a first unwinding device 100, a second unwinding device 200, a laminating device 300, and a rewinding device 400.
[0049] The first unwinding device 100 includes an unwinding roller and is used to unwind the first film 500. In this embodiment, the first film 500 is a self-supporting film, which refers to a porous film used to support a dense film, mainly used in the preparation of the composite film 700. More specifically, the first film 500 includes a first film body and an adhesive layer covering the first film body. During the lamination process, the adhesive layer contacts the second film, and the side of the first film body without the adhesive layer contacts the lamination device.
[0050] The second film is a separator. This application does not specify the type of separator; any known separator capable of being made thin and coated with a solid electrolyte material can be used in this application without departing from the inventive concept. As merely an illustrative example and not a limitation on the scope of protection, the separator can be a microporous polymer separator, including polyolefins, including polyolefins made from homopolymers (derived from a single monomer component) or hybrids (derived from more than one monomer component), wherein the homopolymers and hybrids can be linear or branched. In some aspects, the polyolefin can be polyethylene (PE), polypropylene (PP), or a blend of PE and PP, or a multilayer structured porous membrane of PE and / or PP.
[0051] When the membrane is a porous polymer membrane or a microporous polymer membrane, it can be a single-layer or multi-layer laminate. For example, a single layer of polyolefin can form an entire porous polymer membrane or a microporous polymer membrane. In other embodiments, the membrane can be a fibrous membrane having a large number of pores extending between opposing surfaces. As another example, when the membrane is a multilayer structure formed of multiple polymers, multiple discrete layers of polyolefin can be composited to form the membrane.
[0052] In one embodiment, the microporous polymer membrane may further include a second polymer. This is merely an illustrative example and not a limitation on the scope of protection. The second polymer may be polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), polyamide (nylon), polyurethane, polycarbonate, polyester, polyetheretherketone (PEEK), polyethersulfone (PES), polyimide (PI), polyamide-imide, polyether, polyoxymethylene (e.g., acetal), polybutylene terephthalate, polyethylene naphthenate, polybutene, or polymethylpentene. Polyolefin copolymers, acrylonitrile-butadiene-styrene copolymers (ABS), polystyrene copolymers, polymethyl methacrylate (PMMA), polysiloxane polymers (e.g., polydimethylsiloxane (PDMS)), polybenzimidazole (PBI), polybenzoxazole (PBO), polyphenylene, polyarylene ether ketones, polyfluorocyclobutane, polyvinylidene fluoride copolymers (e.g., PVdF-hexafluoropropylene or (PVdF-HFP)) and polyvinylidene fluoride terpolymers, polyvinyl fluoride, liquid crystal polymers (e.g., VECTRANTM (Hoechst AG, Germany) and... (DuPont, Wilmington, Delaware), polyarylamide, polyphenylene ether, cellulose materials, mesoporous silica, or combinations thereof.
[0053] Furthermore, the diaphragm can be mixed with ceramic materials, or its surface can be coated with ceramic materials. For example, the ceramic coating may include inorganic oxides such as alumina (Al2O3) and silicon dioxide (SiO2), or oxide solid electrolytes such as LLZO, LLTO, and LLZTO, or combinations thereof, or mixtures of inorganic oxides and oxide solid electrolytes.
[0054] As one implementation method, this application does not particularly limit the type of the first film. Without departing from the inventive concept of this application, any known film material with a certain degree of self-support can be used in this application. This is merely an illustrative example and not a limitation on the scope of protection. The first film can be selected from polyethylene terephthalate or polypropylene, polyvinylidene fluoride (PVdF), polyamide (nylon), polyurethane, polycarbonate, polyester, polyetheretherketone (PEEK), polyethersulfone (PES), polyimide (PI), polyamide-imide, polyether, polyoxymethylene (e.g., acetal), polybutylene terephthalate, polyethylene cyclohexane, polybutene, polymethylpentene, polyolefin copolymers, acrylonitrile-butadiene... Diene-styrene copolymers (ABS), polystyrene copolymers, polymethyl methacrylate (PMMA), polysiloxane polymers (e.g., polydimethylsiloxane (PDMS)), polybenzimidazole (PBI), polybenzoxazole (PBO), polyphenylene, polyarylene ether ketones, polyfluorocyclobutane, polyvinylidene fluoride copolymers (e.g., PVdF-hexafluoropropylene or (PVdF-HFP)) and polyvinylidene fluoride terpolymers, polyvinyl fluoride, liquid crystal polymers (e.g., VECTRANTM (Hoechst AG, Germany) and... (DuPont in Wilmington, Delaware), polyarylamide, polyphenylene ether, cellulose.
[0055] It is understood that the first film 500 of this application has a certain mechanical strength, which enables it to serve as a support carrier to support the diaphragm and allow the diaphragm to maintain its intact shape.
[0056] Furthermore, the thickness of the first film 500 is 20-1000 micrometers. Even further, the thickness of the first film can be adjusted according to actual needs, as long as it meets requirements such as mechanical strength. More specifically, the thickness of the first film 500 can be 40, 45, 50, 55, or 60 micrometers; these will not be listed exhaustively here due to space limitations.
[0057] To meet the requirements for lightweight batteries, the separator should be made as thin as possible while meeting relevant performance requirements. However, making the separator thinner can bring other hidden dangers. For example, if the mechanical strength of the separator itself is too low, the separator and the separator are prone to breakage during downstream processing. Therefore, the composite membrane 700 formed by combining a self-supporting membrane and a separator has strong mechanical strength. Coating the composite membrane 700 with a ceramic layer or a corresponding solid electrolyte layer will not easily cause the composite membrane 700 to break.
[0058] On the other hand, the separator 600, being the second thin film, is relatively thin, making it prone to wrinkling during transport. Wrinkled separators and self-supporting films, when laminated at the laminating device 300, affect the quality of the composite film 700. In this application, a second unwinding device 200 is positioned between the first unwinding device 100 and the winding device 400. The second unwinding device 200 unwinds the separator and then directly presses the self-supporting film and separator together. By winding the separator onto the second unwinding device 200, which simultaneously unwinds and presses the separator, wrinkling is avoided. Because the unwinding and laminating of the separator are integrated into a single design, the separator and self-supporting film do not pass through a conveyor roller before lamination, thus reducing the impact of poor conveyor belt movement caused by separator belt suspension on the quality of the composite film formed by laminating the separator and self-supporting film.
[0059] The film laminating equipment also includes a laminating device 300, which abuts against a second unwinding device 200, and a diaphragm and a self-supporting membrane are laminated between the second unwinding device 200 and the laminating device 300 to form a composite film 700.
[0060] The thickness of the second film 600 is 1-20 micrometers. Further, the thickness of the second film 600 is 1-10 micrometers. More specifically, it can be 1, 3, 5, 7, or 10 micrometers. Due to space limitations, these will not be listed here.
[0061] Because an adhesive layer is provided on the side where the first film 500 contacts the second film 600, the second film 600 can quickly overlap with the first film 500 after being unwound by the second unwinding device 200, completely eliminating the tape-carrying process after the second film 600 is unwound, and avoiding the problem of tape curling caused by the diaphragm being too thin.
[0062] This application does not have specific requirements for the composition of the adhesive layer. Without departing from the inventive concept of this application, any known adhesive layer that is adhesive to the diaphragm and a first thin film with self-supporting properties, primarily composed of polymer films, and that can be easily adhered to the first thin film, can be used in this application. This is merely an illustrative example and not a limitation on the scope of protection. The adhesive layer is a fluorinated adhesive.
[0063] In one embodiment, the film laminating equipment further includes an adhesive coating device located between the first unwinding device and the laminating device 300. The adhesive coating device applies an adhesive layer to the first film body. After the first film body is unwound by the first unwinding device, the adhesive coating operation is performed, preventing the first film bodies from sticking together due to the adhesive layer and affecting the unwinding effect. This application does not impose any particular requirements on the specific structure of the adhesive coating device. Any known coating and / or application structure can be used in this application without departing from the inventive concept, such as using a coating head to apply the adhesive layer.
[0064] In one specific embodiment, the second unwinding device 200 includes a pressing roller, and the laminating device 300 includes a laminating roller. The second unwinding device 200 and the laminating device 300 rotate towards each other. As one implementation, the pressing roller and the laminating roller have the same diameter, and the angular velocities of rotation of the second unwinding device 200 and the laminating device 300 are equal. This arrangement facilitates uniform surface pressure on the first film 500 and the second film 600, thereby preventing wrinkling of the film caused by the second unwinding device 200 and the laminating device 300 interleaving.
[0065] In one embodiment, the pressing roller and the composite roller have different diameters.
[0066] Furthermore, the diameter of the pressing roller is smaller than and / or larger than the diameter of the composite roller.
[0067] In one embodiment, the second unwinding device 200 includes only a pressing roller. Thus, after the second film is unwound by the second unwinding device 200, it is directly laminated with the first film, completely eliminating the conveyor belt process from unwinding to pressing of the second film, and solving the problem of edge curling caused by the thin overall thickness of the second film during conveyor belt process.
[0068] The second unwinding device 200 moves in a direction approaching or away from the composite device 300 as the thickness of the second film 600 wound on it changes. Specifically, when a new roll of the second film 600 needs to be added to the second unwinding device 200, the second unwinding device 200 moves in a direction away from the composite device 300. As the thickness of the second film 600 wound on the second unwinding device 200 continuously decreases, the second unwinding device 200 moves in a direction approaching the composite device 300. Further, the second unwinding device 200 can move in real-time in a direction approaching the composite device 300 as the thickness of the second film 600 wound on it decreases. Optionally, the second unwinding device 200 can also be designed to move in a direction approaching the composite device 300 when the thickness of the second film 600 decreases by a certain value.
[0069] Preferably, the pressing roller can move freely in the vertical direction and can freely contact the composite roller under the action of gravity.
[0070] As the second film 600 wound on the second unwinding device 200 and the first film 500 unwound by the first unwinding device 100 are continuously combined, the total thickness of the second film 600 wound on the second unwinding device 200 is correspondingly reduced. Throughout the winding process, the pressing roller can automatically adjust according to the thickness of the second film on the second unwinding device.
[0071] Furthermore, the film laminating equipment also includes a driving device for driving the second unwinding device 200 to move closer to or further away from the laminating device 300. In this embodiment, the driving device includes a cylinder. Since a cylinder has excellent linear driving force, using a cylinder for driving facilitates electrical control and can improve the stability of the lifting and lowering movement of the second unwinding device 200.
[0072] The film laminating equipment also includes a winding device 400, which is used to wind up the composite film 700. The winding device 400 includes a winding roller, and a motor that drives the winding roller to rotate is also provided on one side of the winding roller. The output end of the motor is connected to the rotation shaft of the winding roller. Since the output end of the motor is connected to the rotation shaft of the winding roller, the motor can drive the winding roller to run, thereby providing winding power to the winding roller.
[0073] In one specific embodiment, the film laminating equipment further includes a conveying device for conveying the composite film 700 formed by laminating the first film 500 and the second film 600 to a winding device 400, whereby the winding device 400 completes the winding of the composite film 700. The conveying device includes one or more conveying rollers, the number of which can be selected according to user needs and is not specifically limited here. When there are multiple conveying rollers, the multiple conveying rollers are arranged along the conveying path of the composite film.
[0074] Corresponding to the aforementioned thin film composite apparatus, this application also provides a thin film composite method. Figure 3 A flowchart of a thin film composite method provided in this application embodiment, the method comprising the following steps:
[0075] S1: Unwind the first film using the first unwinding device.
[0076] Specifically, the first unwinding device 100 includes an unwinding roller, and the first film 500 is a self-supporting film.
[0077] S2: The second film is unwound using the second unwinding device and pressed together with the composite device to form a composite film by combining the first film and the second film.
[0078] Specifically, the second unwinding device 200 includes a pressing roller, and the second film 600 is a diaphragm wound on the pressing roller. The pressing roller unwinds and presses the diaphragm wound on it to prevent wrinkling, thereby further improving the quality of the composite film 700 formed by the diaphragm and the self-supporting film.
[0079] S3: The composite film is wound up using a winding device.
[0080] Specifically, the winding device 400 includes a winding roller for winding up the composite film 700 formed by the diaphragm and the self-supporting film.
[0081] As can be seen from the above, the embodiments of this application provide a film lamination device and a lamination method, which integrates the unwinding and lamination of the second film. By winding the second film onto the second unwinding device, the second unwinding device unwinds and presses the second film wound on it at the same time to avoid wrinkling of the second film. The second film does not pass through the conveyor roller before being laminated with the first film, thereby reducing the poor conveying caused by the second film being suspended and affecting the quality of the composite film formed by the lamination of the second film and the first film.
[0082] The foregoing has provided a detailed description of the thin-film composite device and method provided in this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and its core ideas. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A thin film composite device, characterized in that, The film laminating equipment includes a first unwinding device, a second unwinding device, a laminating device, and a winding device; The first unwinding device is used to unwind the first film; The second unwinding device is disposed between the first unwinding device and the winding device. The second unwinding device is used to unwind the second film and press the first film and the second film together. The composite device and the second unwinding device abut each other, and the first film and the second film are composited between the second unwinding device and the composite device to form a composite film. The winding device is used to wind up the composite film.
2. The thin film composite equipment according to claim 1, characterized in that, The second unwinding device and the composite device rotate in opposite directions.
3. The thin film composite equipment according to claim 2, characterized in that, The second unwinding device and the composite device rotate at the same angular velocity.
4. The thin film composite equipment according to claim 1, characterized in that, The second unwinding device moves in a direction that approaches or moves away from the composite device as the thickness of the second film wound on the second unwinding device changes.
5. The thin film composite equipment according to claim 1, characterized in that, The first film includes a first film body and an adhesive layer covering the first film body, the adhesive layer being on the side close to the second film.
6. The thin film composite equipment according to claim 5, characterized in that, The first film body comprises polyethylene terephthalate or polypropylene; And / or, The adhesive layer includes a fluorinated adhesive layer.
7. The thin film composite equipment according to claim 1, characterized in that, The second film comprises a polyethylene terephthalate film or a polypropylene film, and the thickness of the second film is 1-10 micrometers; And / or, The thickness of the first film is 40-60 micrometers.
8. The thin film composite equipment according to claim 1, characterized in that, The first unwinding device includes an unwinding roller; And / or, The second unwinding device includes a pressure roller; And / or, The composite device includes a composite roller; And / or, The winding device includes a winding roller.
9. The thin film composite equipment according to claim 1, characterized in that, The film laminating equipment also includes a driving device for driving the second unwinding device to move closer to or away from the laminating device.
10. A composite method for a thin film composite apparatus as described in any one of claims 1 to 9, characterized in that, The composite method includes: The first film is unwound using the first unwinding device; A second film is unwound using a second unwinding device and then pressed together with a composite device by the second unwinding device to form a composite film by combining the first film and the second film. The composite film is wound up using a winding device.