Intermittent composite film and its manufacturing method, transfer film and its manufacturing apparatus and method

Abstract

Disclosed are an intermittent composite film and a method for manufacturing the same, a transfer film, and a manufacturing apparatus and method therefor. A transfer film is obtained, the transfer film including a load film and a first composite material film, the first composite material film being intermittently placed on the load film. A second composite material film is obtained, and under the same pressure, the bonding force between the second composite material film and the first composite material film is greater than the bonding force between the first composite material film and the load film. The side of the transfer film having the first composite material film is pressure-bonded to the second composite material film to obtain an intermittent composite film.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing composite films, and particularly to intermittent composite films and their manufacturing methods, transfer films, and their manufacturing apparatuses and methods.

Background Art

[0002] Metallic lithium has theoretically the highest energy density (3860 mAh / g) and a low electrode potential (-3.04 V with respect to the standard hydrogen electrode), and has a very high possibility of being used as a negative electrode material for next-generation high-energy batteries or all-solid-state batteries. When metallic lithium is used as a negative electrode material for an all-solid-state battery, usually, metallic lithium is processed into a metallic lithium film with a thickness of 5 to 50 μm and laminated with a copper foil. Metallic lithium participates in an electrochemical reaction as a negative electrode material, and the role of the copper foil is the same as that of a current collector in a liquid lithium-ion battery, and functions as a current collector for electron transfer.

[0003] With the development of lithium-ion battery technology, the enlargement of batteries has gradually become a trend. Then, how to manufacture a large-sized lithium copper composite pole piece? The current general process is to leave a blank copper foil in the width direction of a lithium copper composite film, cut it into pieces, and then weld it to the blank copper foil with tabs secured. To manufacture a large battery by this method, there are strict requirements for the width of the lithium film, and depending on the size of the battery, the width needs to reach 300 mm or more.

[0004] However, at present, it is very difficult to manufacture a wide lithium film. One of the solutions is to completely overlap the lithium film and the copper foil in the width direction and leave a certain gap in the length direction to manufacture an intermittent lithium copper composite film when laminating the metallic lithium film on the copper foil. Then, cut it transversely at the intermittent part and weld the tabs to the gap in the length direction. In this way, a large-sized negative electrode pole piece that meets the requirements of a large battery can be manufactured.

[0005] Chinese Patent Publication No. 114597331 discloses a method for manufacturing an intermittent lithium film. By controlling the intermittent up-and-down movement of a scraper, a part of the metallic lithium layer of a lithium foil PL is scraped off to form an intermittent lithium foil PNL. This method has some inherent limitations. Since lithium metal is scraped off by the contact between the scraper and the lithium foil PL, when the contact force between the scraper and the lithium foil PL layer is strong, there is a very high possibility of damage to the load layer, such as scratches and breaks. Especially when scraping a lithium film with a copper foil, since the thin copper foil itself is easily broken, if the copper foil current collector is damaged, there may be a cell failure. On the other hand, if the contact force is too small, the lithium metal cannot be scraped off cleanly. The remaining lithium metal in the intermittent part will cause major problems in the subsequent cell manufacturing.

[0006] Chinese Utility Model Registration No. 216928627 discloses another method for manufacturing an intermittent lithium film. A release agent is intermittently applied on a copper foil, and a lithium foil strip and the copper foil are combined for rolling. Due to the role of the release agent, after rolling, at the locations where there is a release agent, the lithium foil is not transferred to the copper foil, and at the locations where there is no release agent, the lithium foil is transferred to the copper foil, forming an intermittent lithium copper composite film. However, in this method, the lithium foil at the edge of the intermittent part will be torn and separated. The reliability of separation by tearing is not high, the edge is not clean and consistent, and it may also lead to large-scale defects, thus having a great impact on the subsequent manufacturing of cell pole pieces.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] An object of the present invention is to provide an intermittent composite film, a method for manufacturing the same, a transfer film, and an apparatus and method for manufacturing the same, in order to effectively improve the quality of the intermittent composite film.

Means for Solving the Problems

[0009] The method for manufacturing an intermittent composite film according to the present invention includes the following steps. Obtain a transfer film, the transfer film includes a load film and a first composite material film, and the first composite material film is intermittently provided on the load film. Obtain a second composite material film, and under the same pressure, the bonding force between the second composite material film and the first composite material film is greater than the bonding force between the first composite material film and the load film. The side of the transfer film having the first composite material film is pressure-compounded with the second composite material film to obtain an intermittent composite film.

[0010] Preferably, the load film is a PE film, a PP film, or a PET film.

[0011] The present invention provides an intermittent composite film employing the method for manufacturing the intermittent composite film.

[0012] The present invention provides a transfer film applicable to the method for manufacturing the intermittent composite film, the transfer film includes a load film and a first composite material film, and the first composite material film is intermittently provided on the load film.

[0013] The present invention provides an apparatus for manufacturing a transfer film, which includes a pressure roller, a slitter, and a slitting roller, a composite station and a slitting station are sequentially arranged corresponding to the slitting roller, and the pressure roller cooperates with the slitting roller and is arranged at the composite station.

[0014] The slitting roller includes a roller body and a guide mechanism. The guide mechanism includes a guide member and a first control member. The guide member has a first position and a second position, and is switched between the first position and the second position by the first control member. The first position of the guide member is on the roller peripheral surface of the roller body, and the second position of the guide member is away from the roller peripheral surface of the roller body.

[0015] The slitter is disposed in the slitting station.

[0016] Preferably, the guide mechanism includes a second control member for switching the guide member to a third position. A guide groove is provided on the roller peripheral surface of the slitting roller, and the third position is in the guide groove.

[0017] Preferably, the guide member is rod-shaped.

[0018] Preferably, the guide mechanism includes a guide bracket provided in the guide groove. One side of the guide member is hinged to the guide bracket. The first control member is a first linear driving element, and both ends of the first linear driving element are hinged to the guide member and the guide bracket respectively, driving the guide member to switch between the first position and the second position.

[0019] Preferably, the second control member is a second linear driving element, and both ends of the second linear driving element are connected to the guide bracket and the guide groove respectively, driving the guide member to switch to the third position.

[0020] Preferably, at least two guide grooves are evenly provided on the roller peripheral surface of the slitting roller, and the guide mechanism is provided in each guide groove respectively.

[0021] Preferably, the slitting roller is driven to rotate by a stepping motor or a servo motor, and the rotation angle is equal to 360° divided by the number of the guide grooves.

[0022] Preferably, the slitter is a laser slitter or a mechanical slitter.

[0023] Preferably, the production apparatus for the transfer film further includes a first composite material film unwinding line, a load film unwinding line, and a transfer film winding line. The first composite material film unwinding line and the load film unwinding line intersect at a composite station of a pressure roller and a slitting roller, and the transfer film winding line is arranged behind the slitting roller.

[0024] The first composite material film unwinding line includes a first composite material film unwinding roller.

[0025] The load film unwinding line includes a load film unwinding roller and a first floating roller which are arranged in sequence.

[0026] The transfer film winding line includes a second floating roller and a winding roller which are arranged in sequence.

[0027] The present invention provides a method for manufacturing a transfer film using the production apparatus for the transfer film, including the following steps.

[0028] When the guide member is in the second position, the load film is conveyed to the roller peripheral surface of the slitting roller.

[0029] The first control member switches the guide member to the first position so that the guide member is disposed on the load film.

[0030] Rotate the slitting roller to the composite station, and laminate the first composite material film and the load film by rolling with the pressure roller and the slitting roller.

[0031] Further rotate the slitting roller to the slitting station, and cut the first composite material film on the load film into an intermittent structure through the corresponding guide member of the slitter to obtain an intermittent transfer film.

[0032] After cutting, switch the guide member to the second position with the first control member.

[0033] Preferably, the guide mechanism includes a second control member for switching the guide member to the third position, a guide groove is provided on the roller peripheral surface of the slitting roller, and the third position is within the guide groove.

[0034] Before rotating the slitting roller to the composite station, move the guide member to the third position with the second control member, and draw the corresponding load film into the guide groove.

[0035] After cutting, move the guide member to the first position with the second control member, and further switch the guide member to the second position with the first control member.

Advantages of the Invention

[0036] The method for manufacturing an intermittent composite film according to the present invention indirectly laminates the first composite material film and the second composite material film intermittently placed on the load film, applies the composite pressure to the second composite material film only once, can maximally protect the second composite material film from damage, and the composite film is not easily wrinkled, thus improving the quality and yield of the intermittent composite film. In addition to being used for general intermittent lithium copper composite films, it can also be used for the composite of lithium, lithium alloys and other metals.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0038] Hereinafter, the present invention will be further described.

[0039] The method for manufacturing an intermittent composite film according to the present invention includes the following steps. As shown in FIG. 1, a transfer film 9 is obtained. The transfer film 9 includes a load film 91 and a first composite material film 92. The first composite material film 92 is intermittently placed on the load film 91. A second composite material film is obtained. Under the same pressure, the bonding force between the second composite material film and the first composite material film 92 is greater than the bonding force between the first composite material film 92 and the load film 91. The side of the transfer film 9 having the first composite material film 92 is pressure-bonded to the second composite material film to obtain an intermittent composite film.

[0040] The object to be manufactured in this embodiment is an intermittent composite film in which the first composite material film 92 is intermittently distributed on the second composite material film. Instead of directly manufacturing this, first, a transfer film 9 in which the first composite material film 92 is intermittently distributed on a load film 91 is obtained. The side of the transfer film 9 having the first composite material film 92 is pressure-bonded to the second composite material film to manufacture an intermittent composite film. When the manufacturing is completed, it is not necessary to remove the load film 91 of the transfer film 9, and the load film 91 that plays a protective role during storage and transportation can be retained. When using the intermittent composite film, the load film 91 is removed. Under the same pressure, since the bonding force between the second composite material film and the first composite material film 92 is greater than the bonding force between the first composite material film 92 and the load film 91, when removing the load film 91, the first composite material film 92 and the second composite material film do not separate.

[0041] The first composite material film 92 and the second composite material film are selected according to the needs in actual production. When manufacturing the negative pole piece of a battery, the first composite material film 92 usually uses a lithium film or an alloy lithium film made of lithium and one or more of magnesium, zinc, tin, indium, etc. The second composite film usually uses copper foil, but silver foil may be used for some special applications. Theoretically, the load film 91 only needs to have a bonding force between the load film 91 and the first composite material film 92 that is smaller than the bonding force between the second composite material film and the first composite material film 92 under the same pressure. However, considering the material properties, price, and the above-mentioned protective effect, it is preferable to use plastic films such as PE film, PP film, and PET film.

[0042] The operation of transferring the first composite material film 92 from the transfer film 9 to the second composite material film is relatively simple, but what is actually difficult is the production of the transfer film 9. The production of the transfer film 9 can refer to the existing production apparatus and method for intermittent lithium films, but this application provides a more excellent production apparatus for the transfer film 9. As shown in FIGS. 2 and 3, it includes a pressure roller 4, a slitter 5, and a slitting roller 6. A composite station and a slitting station are arranged in sequence corresponding to the slitting roller 6, and the pressure roller 4 is arranged in the composite station in cooperation with the slitting roller 6.

[0043] The slitting roller 6 includes a roller body and a guide mechanism 60. The guide mechanism 60 includes a guide member 61 and a first control member. The guide member 61 has a first position and a second position, and is switched between the first position and the second position by the first control member. The first position of the guide member 61 is on the roller peripheral surface of the roller body, and the second position of the guide member 61 is away from the roller peripheral surface of the roller body.

[0044] The slitter 5 is arranged at the slitting station.

[0045] The production method of the transfer film 9 using this apparatus includes the following steps. When the guide member 61 is in the second position, the load film 91 is conveyed onto the roller peripheral surface of the slitting roller 6. The first control member switches the guide member 61 to the first position so that the guide member 61 is arranged on the load film 91. The slitting roller 6 is rotated to the composite station, and the first composite material film 92 and the load film 91 are laminated by the rolling process of the pressure roller 4 and the slitting roller 6. Furthermore, the slitting roller 6 is rotated to the slitting station, and the first composite material film 92 on the load film 91 is cut into an intermittent structure using the guide member 61 corresponding to the slitter 5 to obtain an intermittent transfer film 9.

[0046] After cutting, the first control member switches the guide member 61 to the second position.

[0047] When the guide member 61 is in the second position, the guide member 61 is separated from the roller peripheral surface of the slitting roller 6, and the load film 91 can be conveyed to the roller peripheral surface of the slitting roller 6. After the guide member 61 is switched to the first position, it comes to be located on the load film 91. Thus, when the first composite material film 92 and the load film 91 are laminated, due to the action of the guide member 61, the first composite material film 92 and the load film 91 at the position of the guide member 61 are not laminated, and it becomes more convenient to later cut the first composite material film using the slitter 5. When the unlaminated first composite material film 92 is cut with the slitter 5, the intermittent transfer film 9 is formed.

[0048] In lamination, when the guide member 61 is on the roller peripheral surface, it affects the quality of lamination, and only a thin material can be selected as the guide member 61. To solve this problem, in a preferred embodiment of the present application, the guide mechanism 60 includes a second control member for switching the guide member 61 to the third position, a guide groove 65 is provided on the roller peripheral surface of the slitting roller 6, and the third position is within the guide groove 65.

[0049] Before rotating the slitting roller 6 to the composite station, the second control member moves the guide member 61 to the third position, and draws the corresponding load film 91 into the guide groove 65.

[0050] After cutting, the second control member moves the guide member 61 to the first position, and further the first control member switches the guide member 61 to the second position.

[0051] In this way, in the lamination process, the second control member being within the guide groove 65 can avoid the lamination pressure, and only the load film 91 on the roller peripheral surface is laminated with the first laminate. In the cutting process, the load film 91 that does not participate in the lamination and is within the guide groove 65 is separated from the first laminate by a sufficient distance, so that the cutting of the first laminate becomes easier, and an intermittent structure can be formed by cutting only once.

[0052] Regarding the specific shape of the guide member 61, when the guide member 61 is on the roller peripheral surface in the lamination process, the guide member 61 is preferably sheet-shaped, and its curvature may be made to coincide with the roller peripheral surface. When it is necessary to switch the position within the guide groove 65, the guide member 61 is preferably rod-shaped. Thereby, the load film 91 can be smoothly drawn into the guide groove 65, and damage to the load film 91 can be prevented.

[0053] The specific arrangements of the first control member and the second control member can take various forms. For example, the first control member and the second control member can be arranged on the end face of the roller, and the first control member and the second control member may be driven by the same driving device. As shown in FIG. 2, in a preferred embodiment of the present application, the guide mechanism 60 includes a guide bracket 62 provided in the guide groove 65. One side of the guide member 61 is hinged to the guide bracket 62. The first control member is the first linear driving element 63. Both ends of the first linear driving element 63 are hinged to the guide member 61 and the guide bracket 62 respectively, and drive the guide member 61 to switch between the first position and the second position. The guide member 61 is rotatable on the roller circumferential surface, that is, in the first position, and is rotatable outside the roller circumferential surface, that is, in the second position. The options for the first position and the second position are not limited to one. When the guide member 61 is in the first position, if it can be located on the load film 91, the load film 91 can be drawn into the guide groove 65. Also, when the guide member 61 is in the first position, it should not interfere with the load film 91 being wound around the roller circumferential surface of the slitting roller 6. For example, in the embodiment of FIG. 4, the first position of the guide member 61 is perpendicular to the roller end face, and the second position is parallel to the roller end face. Before point a, the load film 91 is conveyed onto the roller circumferential surface of the slitting roller 6. At point a, the guide member 61 switches to the first position and presses the load film 91. Before point b, the guide member 61 switches to the third position and draws the load film 91 into the guide groove 65. At point b, it is compounded, cut at point c, and when the cutting is completed, the guide member 61 switches to the third position.

[0054] Based on this, in order to realize the switching of the guide member 61 to the third position, in a preferred embodiment of the present application, the second control member is the second linear drive element 64. Both ends of the second linear drive element 64 are respectively connected to the guide bracket 62 and the guide groove 65, and drive the guide member 61 to perform the switching to the third position. By contracting the second linear drive element 64, the guide bracket 62, the first linear drive element 63, and the guide member 61 are moved toward the center of the roller, the guide member 61 is moved to the third position, and the second linear drive element 64 can extend and move in a direction away from the center of the roller as a whole. The first linear drive element 63 and the second linear drive element 64 may both be an electric push rod, an air cylinder, a hydraulic cylinder, etc., but preferably an air cylinder.

[0055] One guide groove 65 and the guide mechanism 60 can be used to manufacture the intermittent transfer film 9, but the production efficiency is low. In a preferred embodiment of the present application, at least two guide grooves 65 are evenly provided on the roller peripheral surface of the slitting roller 6, and the guide mechanisms 60 are respectively provided in each guide groove 65. The length of each section of the first composite film 92 in the manufactured intermittent transfer film 9 is the sum of the arc length between two adjacent guide grooves of the slitting roller 6 and the width of the guide groove 65. The length of the intermittent part is about twice the depth of pulling the load film 91 into the guide groove 65. The length of each section of the first composite film 92 can be adjusted by adjusting the arc length between the guide grooves 65, and the length of the intermittent part can be adjusted by adjusting the depth of pulling the load film 91 into the guide groove 65. The width of the guide groove 65 is preferably as narrow as possible, and it is preferably controlled to be about 0.5 cm to 2 cm.

[0056] To facilitate the cooperation of the slitting roller 6 at each workstation, the slitting roller 6 is preferably driven to rotate by a stepping motor or a servo motor. The rotation angle is equal to 360° divided by the number of guide grooves. Each time it rotates, an intermittent first composite material film is formed, and the rotation angle can be accurately controlled by a stepping motor or a servo motor.

[0057] The slitter 5 can use existing slitting devices such as a laser slitter 5 or a mechanical slitter 5 such as a blade or a cutter head. Preferably, a laser slitter 5 is used. Since the cutting force of the laser slitter 5 is relatively small, the stability of the cutting operation in the lamination can be ensured.

[0058] The manufacturing apparatus for the transfer film 9 according to the present invention adds an existing unwinding and winding structure, cooperates with an operation control controller such as a PLC or a microcomputer, and can realize continuous automatic production. As shown in FIG. 4, in a preferred embodiment of the present application, the manufacturing apparatus for the transfer film 9 further includes a first composite material film 92 unwinding line, a load film 91 unwinding line, and a transfer film 9 winding line. The first composite material film 92 unwinding line and the load film 91 unwinding line intersect at a composite station of the pressure roller 4 and the slitting roller 6, and the transfer film 9 winding line is arranged behind the slitting roller 6.

[0059] The first composite material film 92 unwinding line includes a first composite material film 92 unwinding roller 3.

[0060] The load film 91 unwinding line includes a load film unwinding roller 1 and a first floating roller 2 arranged in sequence.

[0061] The transfer film 9 winding line includes a second floating roller 7 and a winding roller 8 arranged in sequence.

[0062] The first composite film unwinding line 92 is used for unwinding and conveying the composite material, the load film unwinding line 91 is used for unwinding and conveying the load film 91, and the transfer film winding line 9 is used for conveying and winding the manufactured transfer film 9. Since it is necessary to draw the load film 91 into the guide groove 65 before lamination, the first floating roller 2 for applying tension is provided. On the other hand, since it is necessary to flatten it during winding, the second floating roller 7 for providing the necessary tension in the transfer film winding line 9 is provided.

[0063] (Cross - reference to related applications) This application claims the rights and priority of Chinese Patent Application CN2023111568474 filed on September 8, 2023, and is incorporated herein by reference in its entirety for all purposes.

Explanation of reference numerals

[0064] 1 Load film unwinding roller 2 First floating roller 3 First composite film unwinding roller 4 Pressing roller 5 Slitter 6 Slitting roller 60 Guide mechanism 61 Guide member 62 Guide bracket 63 First linear drive element 64 Second linear drive element 65 Guide groove 7 Second floating roller 8 Winding roller 9 Transfer film 91 Load film 92 First composite film

Claims

1. Obtain a transfer film, the transfer film comprising a load film and a first composite film, the first composite film being intermittently disposed on the load film; obtaining a second composite film, wherein under the same pressure, the bonding force between the second composite film and the first composite film is greater than the bonding force between the first composite film and the load film; A method for producing an intermittent composite film, characterized in that the side of the transfer film having the first composite film is pressurized and composited with the second composite film to obtain an intermittent composite film.

2. 2. The method for manufacturing an intermittent composite film according to claim 1, wherein the load film is a PE film, a PP film, or a PET film.

3. An intermittent composite film produced by the method for producing an intermittent composite film according to any one of claims 1 to 2.

4. A transfer film used in the method for manufacturing an intermittent composite film described in any one of claims 1 to 2, characterized in that it comprises a load film and a first composite film, and the first composite film is intermittently provided on the load film.

5. The present invention includes a pressure roller, a slitter, and a slitting roller, and a composite station and a slitting station are arranged in sequence corresponding to the slitting roller, and the pressure roller is arranged in the composite station in cooperation with the slitting roller; the slitting roller comprises a roller body and a guide mechanism, the guide mechanism comprises a guide member and a first control member, the guide member has a first position and a second position and is switched between the first position and the second position by the first control member, the first position of the guide member is on the roller circumferential surface of the roller body and the second position of the guide member is away from the roller circumferential surface of the roller body, The transfer film manufacturing apparatus is characterized in that the slitter is disposed at the slitting station.

6. The transfer film manufacturing apparatus described in claim 5, characterized in that the guide mechanism is provided with a second control member for switching the guide member to a third position, a guide groove is provided on the roller surface of the slitting roller, and the third position is within the guide groove.

7. 7. The apparatus for producing a transfer film according to claim 6, wherein the guide member is rod-shaped.

8. The transfer film manufacturing device described in claim 6, characterized in that the guide mechanism comprises a guide bracket arranged in the guide groove, one side of the guide member is hinged to the guide bracket, the first control member is a first linear driving element, both ends of which are hinged to the guide member and the guide bracket, respectively, and drive the guide member to switch between the first position and the second position.

9. The transfer film manufacturing device described in claim 8, characterized in that the second control member is a second linear driving element, both ends of which are connected to the guide bracket and the guide groove, respectively, and drive the guide member to switch to the third position.

10. 7. The apparatus for producing a transfer film according to claim 6, wherein at least two guide grooves are evenly spaced on the peripheral surface of the slitting roller, and the guide mechanism is provided in each guide groove.

11. The apparatus for producing a transfer film according to claim 10, wherein the slitting roller is driven to rotate by a stepping motor or a servo motor, and a rotation angle is equal to 360° divided by the number of the guide grooves.

12. 6. The apparatus for producing a transfer film according to claim 5, wherein the slitter is a laser slitter or a mechanical slitter.

13. The present invention further includes a first composite film unwinding line, a load film unwinding line, and a transfer film winding line, the first composite film unwinding line and the load film unwinding line intersecting at a combined station of a pressure roller and a slitting roller, and the transfer film winding line being disposed after the slitting roller; the first composite film unwinding line comprises a first composite film unwinding roller; The loaded film unwinding line includes a loaded film unwinding roller and a first floating roller arranged in sequence; The transfer film manufacturing apparatus according to any one of claims 5 to 12, characterized in that the transfer film winding line comprises a second floating roller and a winding roller arranged in sequence.

14. When the guide member is in the second position, the loaded film is transported to a roller circumferential surface of the slitting roller; The first control member switches the guide member to a first position so that the guide member is positioned on the load film; The slitting roller is rotated to a combining station, and the first composite film and the load film are combined by rolling with the pressure roller and the slitting roller; Further, the slitting roller is rotated to a slitting station, and the first composite film on the load film is cut into an intermittent structure through a guide member corresponding to the slitter, to obtain an intermittent transfer film; A method for producing a transfer film using the transfer film producing apparatus described in any one of claims 5 to 13, characterized in that after cutting, the guide member is switched to the second position by the first control member.

15. the guide mechanism includes a second control member for switching the guide member to a third position, a guide groove is provided on the roller peripheral surface of the slitting roller, and the third position is within the guide groove; before rotating the slitting roller to the combining station, moving the guide member to a third position with the second control member to draw the corresponding loaded film into the guide groove; The method for producing a transfer film according to claim 14, characterized in that, after cutting, the second control member moves the guide member to the first position, and the first control member further switches the guide member to the second position.

Images