Preparation device and preparation method of film-coated lithium strip

Abstract

The invention discloses a preparation device and a preparation method of a film-coated lithium strip, and relates to the technical field of lithium strip processing, the preparation device comprises a mounting plate, and the middle part of the mounting plate is sequentially provided with a primary rolling unit and a secondary rolling and film-coating unit; a lithium strip unwinding roller is mounted at one end of the mounting plate, and a lithium strip deviation corrector is mounted between the lithium strip unwinding roller and the primary rolling unit; a lithium foil smoothing roller group is mounted in the middle of the primary rolling unit and the secondary rolling and laminating unit; the other end of the mounting plate is provided with a film-coated lithium strip winding roller; a film covering type lithium strip deviation corrector is mounted between the film covering type lithium strip winding roller and the secondary rolling film covering unit; the preparation method comprises the following steps: S1, primary rolling; s2, flattening is conducted; s3, lower covering film; and S4, rolling is conducted. According to the preparation device and the preparation method of the film-coated lithium strip, on one hand, the lithium strip is convenient to transport, on the other hand, the lithium strip can be conveniently stripped from a lining film to be compounded with other metal plates, and the roller groups can be prevented from sticking materials in the production and calendering process.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium ribbon processing, and in particular to a preparation device and a preparation method for a film-coated lithium ribbon. Background Art

[0002] With the demand for high energy density and high safety chemical power sources from electrical products such as smart phones, tablets, and electric vehicles, the energy density of commercial lithium-ion secondary batteries with graphite as the negative electrode has limited room for development and has almost reached its limit. The currently used organic electrolytes have safety issues such as flammability, corrosion, and poor thermal stability, which restricts the development of traditional lithium-ion batteries. All-solid-state batteries can solve the above safety hazards. Compared with traditional lithium-ion batteries, solid-state batteries have higher energy density, longer cycle life, and better safety.

[0003] The negative electrode of solid-state batteries currently used is generally a lithium negative electrode made of ultra-thin lithium strips (thickness varies from 10um to 50um) compounded on copper foil or pole pieces. Since metallic lithium itself is very soft, the ultra-thin lithium strip will be attached to a layer of lining film and rolled together after being calendered and separated from the release film. When the ultra-thin lithium strip and the copper foil or pole piece are pressed and compounded by a pressing device, the lining film needs to be peeled off from the ultra-thin lithium strip in advance. However, the peeling force of the lining film and the lithium strip after this calendering treatment method is almost zero. The lithium strip is very easy to detach from the diaphragm and break during transportation before compounding; if the lithium strip is not separated from the release film after calendering, and the release film is directly used as the lining film, the peeling force between the lithium strip and the lining film is too large and cannot be peeled off, and the lithium strip cannot be normally compounded to the copper foil or pole piece. And due to the characteristics of metallic lithium itself, there will be a problem of sticking when slitting and extruding ultra-thin lithium strips.

[0004] How to develop a device and method for preparing a coated lithium belt, which can facilitate the transportation of the lithium belt on the one hand, and facilitate the peeling of the lining film and the compounding with other metal sheets on the other hand, and can avoid the roller group sticking during the production calendering process, has become a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0005] The purpose of the present invention is to provide a device and method for preparing a film-coated lithium belt to solve the problems listed in the background technology.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention discloses a device for preparing a film-coated lithium strip, comprising a mounting plate, wherein a primary rolling unit and a secondary rolling film-coating unit are sequentially mounted in the middle of the mounting plate;

[0008] A lithium strip unwinding roller is installed at one end of the mounting plate, and a lithium strip deviation corrector is installed between the lithium strip unwinding roller and the middle of the primary rolling unit; a lithium foil smoothing roller group is installed between the primary rolling unit and the middle of the secondary rolling and coating unit;

[0009] The other end of the mounting plate is provided with a film-coated lithium strip winding roller;

[0010] A film-coated lithium strip deviation corrector is installed in the middle of the film-coated lithium strip winding roller and the secondary rolling film-coating unit;

[0011] A lithium ribbon is wound on the lithium ribbon unwinding roller, and the free end of the lithium ribbon sequentially passes through the lithium ribbon deflection corrector, the primary rolling unit, the lithium foil smoothing roller group, the secondary rolling coating unit and the coated lithium ribbon deflection corrector and is wound on the coated lithium ribbon winding roller.

[0012] Preferably, the primary rolling unit comprises a release film unwinding roller group, a primary rolling roller group and a release film winding roller group;

[0013] The release film unwinding roller group, the primary rolling roller group and the release film winding roller group are each provided with two upper and lower rollers, and the lithium belt separates the release film unwinding roller group, the primary rolling roller group and the release film winding roller group into two upper and lower parts.

[0014] Preferably, the upper roller of the release film unwinding roller group and the lower roller of the release film unwinding roller group are both wound with release film, and the free end of the release film on the upper roller of the release film unwinding roller group passes through the lower surface of the upper roller of the primary rolling roller group and is wound around the upper roller of the release film winding roller group;

[0015] The free end of the release film on the lower roller of the release film unwinding roller group passes through the upper surface of the lower roller of the primary rolling roller group and is wound around the lower roller of the release film winding roller group.

[0016] Preferably, the secondary rolling coating unit comprises a lining film unwinding roller group, a secondary rolling roller group and a lining film winding roller, the lining film unwinding roller group and the secondary rolling roller group are both provided with upper and lower rollers, and the lithium belt separates the lining film unwinding roller group and the secondary rolling roller group into upper and lower parts;

[0017] The upper roller of the lining film unwinding roller group and the lower roller of the lining film unwinding roller group are both wound with lining film, and the free end of the lining film on the upper roller of the lining film unwinding roller group passes through the lower surface of the upper roller of the secondary rolling roller group and is wound on the lining film winding roller;

[0018] The free end of the lining film on the lower roller of the lining film unwinding roller group passes through the upper surface of the lower roller of the secondary rolling roller group and is imprinted on the lower surface of the lithium strip.

[0019] Preferably, the liner film and the lithium tape are wound on the film-coated lithium tape winding roller.

[0020] A method for preparing a film-coated lithium belt comprises the following steps:

[0021] S1, primary rolling, the release film unwinding roller group and the release film winding roller group work, the release film is coated on the upper roller of the primary rolling roller group and the lower roller of the primary rolling roller group, the free end of the lithium ribbon passes through the lithium ribbon deviation corrector and enters the primary rolling roller group for primary rolling to form lithium foil, and the lithium foil is peeled off from the release film;

[0022] S2, smoothing, the lithium foil is smoothed by a lithium foil smoothing roller group;

[0023] S3, lower coating, the smoothed lithium foil is rolled by a secondary rolling roller group to form a lithium film, and the lower surface of the lithium film is laminated with the liner film;

[0024] S4, winding up, the lithium film with the liner film underneath passes through the film-coated lithium belt deviation corrector and is wound on the film-coated lithium belt winding roller.

[0025] Preferably, in step S1, the thickness of the lithium tape is 0.1-1.2 mm, and the peeling force between the lithium foil and the release film is 2-20 g.

[0026] Preferably, the thickness of the lithium foil after smoothing in step S2 is 10-50 um.

[0027] Preferably, the lining film is any one of a polypropylene film, a polyethylene film, and a mixed film of polypropylene and polyethylene, the lining film does not need to be pretreated, and the lining film is coated with a silicone oil layer.

[0028] Preferably, in step S3, the pressure when the lithium membrane and the liner membrane are laminated is 0.1-1 MPa, and the rolling speed of the secondary rolling roller group is 5-50 m / min.

[0029] Compared with the prior art, the beneficial technical effects of the present invention are:

[0030] 1) Compared with the common lithium foil rolled together with a layer of liner film, the peeling force between the lithium foil and the liner film obtained by the preparation method of the film-coated lithium strip of the present invention is higher, the lithium foil is not easy to deform or break during transportation before lamination, and the utilization rate of the lithium foil during lamination is ≥98%;

[0031] 2) When this type of coated lithium ribbon is used to laminate with copper foil or electrode, the lithium foil will not fall off from the liner film during transportation before lamination due to its own gravity, causing the lithium ribbon to deform or break, and it is easy to separate from the liner film during the lamination process, and can be laminated with the copper foil or electrode normally, and will not stick to the film and cannot be separated due to excessive peeling force;

[0032] 3) The lining film is coated with a silicone oil layer, which can make the surface of the ultra-thin lithium belt oily, solving the problem of sticking when the ultra-thin lithium belt is extruded and cut. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] Figure 1 It is a front view schematic diagram of a device for preparing a film-coated lithium belt according to the present invention.

[0035] Explanation of the accompanying reference numerals: 1. lithium strip unwinding roller; 2. lithium strip deflection corrector; 3. release film unwinding roller group; 4. primary rolling roller group; 5. release film winding roller group; 6. lithium foil smoothing roller group; 7. lining film unwinding roller group; 8. secondary rolling roller group; 9. lining film winding roller; 10. film-coated lithium strip deflection corrector; 11. film-coated lithium strip winding roller; 12. mounting plate. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 used to limit the present invention.

[0037] like Figure 1 As shown, a preparation device for a coated lithium strip includes a mounting plate 12, wherein a primary rolling unit and a secondary rolling coating unit are sequentially mounted in the middle of the mounting plate 12;

[0038] A lithium strip unwinding roller 1 is installed at one end of the mounting plate 12, and a lithium strip deviation corrector 2 is installed between the lithium strip unwinding roller 1 and the middle of the primary rolling unit; a lithium foil smoothing roller group 6 is installed between the primary rolling unit and the middle of the secondary rolling and laminating unit;

[0039] The other end of the mounting plate 12 is mounted with a film-coated lithium strip winding roller 11;

[0040] The coated lithium strip winding roller 11 and the middle of the secondary rolling coating unit are provided with a coated lithium strip deviation corrector 10;

[0041] A lithium ribbon is wound on the lithium ribbon unwinding roller 1, and the free end of the lithium ribbon passes through the lithium ribbon deflection corrector 2, the primary rolling unit, the lithium foil smoothing roller group 6, the secondary rolling coating unit and the coated lithium ribbon deflection corrector 10 in sequence and is wound on the coated lithium ribbon winding roller 11.

[0042] Specifically, the primary rolling unit includes a release film unwinding roller group 3, a primary rolling roller group 4 and a release film winding roller group 5;

[0043] The release film unwinding roller group 3, the primary rolling roller group 4 and the release film winding roller group 5 are all provided with two upper and lower rollers, and the lithium belt separates the release film unwinding roller group 3, the primary rolling roller group 4 and the release film winding roller group 5 into two upper and lower parts.

[0044] Specifically, the upper roller of the release film unwinding roller group 3 and the lower roller of the release film unwinding roller group 3 are both wound with release film, and the free end of the release film on the upper roller of the release film unwinding roller group 3 passes through the lower surface of the upper roller of the primary rolling roller group 4 and is wound around the upper roller of the release film winding roller group 5;

[0045] The free end of the release film on the lower roller of the release film unwinding roller group 3 passes through the upper surface of the lower roller of the primary rolling roller group 4 and is wound around the lower roller of the release film winding roller group 5 .

[0046] Specifically, the secondary rolling coating unit includes a lining film unwinding roller group 7, a secondary rolling roller group 8 and a lining film winding roller 9, the lining film unwinding roller group 7 and the secondary rolling roller group 8 are both provided with upper and lower rollers, and the lithium belt separates the lining film unwinding roller group 7 and the secondary rolling roller group 8 into upper and lower parts;

[0047] The upper roller of the lining film unwinding roller group 7 and the lower roller of the lining film unwinding roller group 7 are both wound with lining film, and the free end of the lining film on the upper roller of the lining film unwinding roller group 7 passes through the lower surface of the upper roller of the secondary rolling roller group 8 and is wound on the lining film winding roller 9;

[0048] The free end of the lining film on the lower roller of the lining film unwinding roller group 7 passes through the upper surface of the lower roller of the secondary rolling roller group 8 and is imprinted on the lower surface of the lithium strip.

[0049] Specifically, the liner film and the lithium tape are wound on the film-coated lithium tape winding roller 11 .

[0050] A method for preparing a film-coated lithium belt comprises the following steps:

[0051] S1, primary rolling, the release film unwinding roller group and the release film winding roller group work, the release film is coated on the upper roller of the primary rolling roller group and the lower roller of the primary rolling roller group, the free end of the lithium ribbon passes through the lithium ribbon deviation corrector and enters the primary rolling roller group for primary rolling to form lithium foil, and the lithium foil is peeled off from the release film;

[0052] S2, smoothing, the lithium foil is smoothed by a lithium foil smoothing roller group;

[0053] S3, lower coating, the smoothed lithium foil is rolled by a secondary rolling roller group to form a lithium film, and the lower surface of the lithium film is laminated with the liner film;

[0054] S4, winding up, the lithium film with the liner film underneath passes through the film-coated lithium belt deviation corrector and is wound on the film-coated lithium belt winding roller.

[0055] Specifically, in step S1, the thickness of the lithium tape is 0.1-1.2 mm, and the peeling force between the lithium foil and the release film is 2-20 g.

[0056] Specifically, the thickness of the lithium foil after smoothing in step S2 is 10-50 um.

[0057] Specifically, the lining film is any one of a polypropylene film, a polyethylene film, and a mixed film of polypropylene and polyethylene. The lining film does not need to be pretreated, and the lining film is coated with a silicone oil layer.

[0058] Specifically, in step S3, the pressure when the lithium membrane and the liner membrane are laminated is 0.1-1 MPa, and the rolling speed of the secondary rolling roller group is 5-50 m / min.

[0059] Embodiment 1

[0060] 1) Prepare 0.2 mm thick lithium strip, two release films for lithium foil calendering, and two polypropylene films;

[0061] 2) Assemble the release film for lithium strip calendering on the release film unwinding roller group 3 and pass through the primary rolling roller group 4 to be assembled on the release film winding roller group 5; Assemble the polypropylene film on the lining film unwinding roller group 7 and pass through the secondary rolling roller group 8, the upper lining film is assembled to the upper roller of the lining film winding roller group 9, and the lower lining film passes through the film-coated lithium strip deviation corrector 10 to be assembled on the film-coated lithium strip winding roller 11; Assemble the lithium strip on the lithium strip unwinding roller 1, pass through the lithium strip deviation corrector 2, the primary rolling roller group 4, the lithium foil smoothing roller group 6, the secondary rolling roller group 8, the film-coated lithium strip deviation corrector 10 in sequence, and assemble it on the film-coated lithium strip winding roller 11;

[0062] 3) setting a rolling pressure of 1.0 MPa and a rolling speed of 5 m / min, rolling a 0.2 mm thick lithium strip into a 10 μm lithium foil and separating it from the release film;

[0063] 4) The secondary rolling pressure was set to 0.3 MPa and the speed was set to 5 m / min, and the lithium film was laminated on the liner film to obtain a laminated lithium belt with a peeling force of 5 g and a lithium film thickness of 10 μm.

[0064] Embodiment 2

[0065] 1) Prepare 0.2 mm thick lithium strip, two release films for lithium foil calendering, and two polypropylene films.

[0066] 2) Assemble the release film for lithium foil calendering on the release film unwinding roller group 3 and pass through the primary rolling roller group 4 to be assembled on the release film winding roller group 5; Assemble the polypropylene film on the liner film unwinding roller group 7 and pass through the secondary rolling roller group 8, the upper liner film is assembled to the upper roller of the liner film winding roller group 9, and the lower liner film passes through the film-coated lithium belt deviation corrector 10 to be assembled on the film-coated lithium belt winding roller 11; Assemble the lithium belt on the lithium belt unwinding roller 1, pass through the lithium belt deviation corrector 2, the primary rolling roller group 4, the lithium foil smoothing roller group 6, the secondary rolling roller group 8, the film-coated lithium belt deviation corrector 10 in sequence, and assemble it on the film-coated lithium belt winding roller 11;

[0067] 3) setting a rolling pressure of 0.9 MPa and a rolling speed of 8 m / min, rolling a 0.2 mm thick lithium strip into a 20 μm lithium foil and separating it from the release film;

[0068] 4) The secondary rolling pressure was set to 0.33 MPa and the speed was set to 8 m / min, and the lithium film was laminated on the liner film to obtain a film-coated lithium belt with a peeling force of 5 g and a lithium foil thickness of 20 μm.

[0069] Embodiment 3

[0070] 1) Prepare 0.2 mm thick lithium strip, two release films for lithium foil calendering, and two polypropylene films;

[0071] 2) Assemble the release film for lithium foil calendering on the release film unwinding roller group 3 and pass through the primary rolling roller group 4 to be assembled on the release film winding roller group 5; Assemble the polypropylene film on the liner film unwinding roller group 7 and pass through the secondary rolling roller group 8, the upper liner film is assembled to the upper roller of the liner film winding roller group 9, and the lower liner film passes through the film-coated lithium belt deviation corrector 10 to be assembled on the film-coated lithium belt winding roller 11; Assemble the lithium belt on the lithium belt unwinding roller 1, pass through the lithium belt deviation corrector 2, the primary rolling roller group 4, the lithium foil smoothing roller group 6, the secondary rolling roller group 8, the film-coated lithium belt deviation corrector 10 in sequence, and assemble it on the film-coated lithium belt winding roller 11;

[0072] 3) setting a rolling pressure of 0.7 MPa and a rolling speed of 20 m / min, rolling a 0.2 mm thick lithium strip into a 50 μm lithium foil and separating it from the release film;

[0073] 4) The secondary rolling pressure was set to 0.35 MPa and the speed was set to 20 m / min, and the lithium film was laminated on the liner film to obtain a laminated lithium belt with a peeling force of 5 g and a lithium film thickness of 50 μm.

[0074] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0075] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A device for preparing a film-coated lithium strip, comprising a mounting plate (12), characterized in that: A primary rolling unit and a secondary rolling and laminating unit are sequentially installed in the middle of the installation plate (12); A lithium strip unwinding roller (1) is installed at one end of the mounting plate (12); a lithium strip deviation corrector (2) is installed between the lithium strip unwinding roller (1) and the middle of the primary rolling unit; a lithium foil smoothing roller group (6) is installed between the primary rolling unit and the middle of the secondary rolling coating unit; A film-coated lithium strip winding roller (11) is installed at the other end of the mounting plate (12); A film-coated lithium strip deviation corrector (10) is installed in the middle of the film-coated lithium strip winding roller (11) and the secondary rolling film-coating unit; A lithium ribbon is wound on the lithium ribbon unwinding roller (1), and the free end of the lithium ribbon sequentially passes through the lithium ribbon deflection corrector (2), the primary rolling unit, the lithium foil smoothing roller group (6), the secondary rolling coating unit and the coated lithium ribbon deflection corrector (10), and is wound on the coated lithium ribbon winding roller (11).

2. The device for preparing a film-coated lithium belt according to claim 1, characterized in that: The primary rolling unit comprises a release film unwinding roller group (3), a primary rolling roller group (4) and a release film winding roller group (5); The release film unwinding roller group (3), the primary rolling roller group (4) and the release film winding roller group (5) are each provided with two upper and lower rollers, and the lithium belt separates the release film unwinding roller group (3), the primary rolling roller group (4) and the release film winding roller group (5) into two upper and lower parts.

3. The device for preparing a film-coated lithium belt according to claim 2, characterized in that: The upper roller of the release film unwinding roller group (3) and the lower roller of the release film unwinding roller group (3) are both wound with release film, and the free end of the release film on the upper roller of the release film unwinding roller group (3) passes through the lower surface of the upper roller of the primary rolling roller group (4) and is wound around the upper roller of the release film winding roller group (5); The free end of the release film on the lower roller of the release film unwinding roller group (3) passes through the upper surface of the lower roller of the primary rolling roller group (4) and is wound around the lower roller of the release film winding roller group (5).

4. The device for preparing a film-coated lithium belt according to claim 1, characterized in that: The secondary rolling coating unit comprises a lining film unwinding roller group (7), a secondary rolling roller group (8) and a lining film winding roller (9), wherein the lining film unwinding roller group (7) and the secondary rolling roller group (8) are both provided with upper and lower rollers, and the lithium belt separates the lining film unwinding roller group (7) and the secondary rolling roller group (8) into upper and lower parts; The upper roller of the lining film unwinding roller group (7) and the lower roller of the lining film unwinding roller group (7) are both wound with lining film, and the free end of the lining film on the upper roller of the lining film unwinding roller group (7) passes through the lower surface of the upper roller of the secondary rolling roller group (8) and is wound on the lining film winding roller (9); The free end of the lining film on the lower roller of the lining film unwinding roller group (7) passes through the upper surface of the lower roller of the secondary rolling roller group (8) and is imprinted on the lower surface of the lithium strip.

5. The device for preparing a film-coated lithium belt according to claim 4, characterized in that: The liner film and the lithium tape are wound on the film-coated lithium tape winding roller (11).

6. A method for preparing a film-coated lithium ribbon, which is accomplished by using a film-coated lithium ribbon preparation device according to any one of claims 1 to 5, characterized in that: The steps include: S1, primary rolling, the release film unwinding roller group and the release film winding roller group work, the release film is coated on the upper roller of the primary rolling roller group and the lower roller of the primary rolling roller group, the free end of the lithium ribbon passes through the lithium ribbon deviation corrector and enters the primary rolling roller group for primary rolling to form lithium foil, and the lithium foil is peeled off from the release film; S2, smoothing, the lithium foil is smoothed by a lithium foil smoothing roller group; S3, lower coating, the smoothed lithium foil is rolled by a secondary rolling roller group to form a lithium film, and the lower surface of the lithium film is laminated with the liner film; S4, winding up, the lithium film with the liner film underneath passes through the film-coated lithium belt deviation corrector and is wound on the film-coated lithium belt winding roller.

7. The method for preparing a film-coated lithium ribbon according to claim 6, characterized in that: In step S1, the thickness of the lithium tape is 0.1-1.2 mm, and the peeling force between the lithium foil and the release film is 2-20 g.

8. The method for preparing a film-coated lithium ribbon according to claim 6, characterized in that: The thickness of the lithium foil after smoothing in step S2 is 10-50 um.

9. The method for preparing a film-coated lithium ribbon according to claim 6, characterized in that: The lining film is any one of a polypropylene film, a polyethylene film, and a mixed film of polypropylene and polyethylene. The lining film does not need to be pretreated, and the lining film is coated with a silicone oil layer.

10. The method for preparing a film-coated lithium ribbon according to claim 6, characterized in that: In step S3, the pressure when the lithium membrane and the liner membrane are laminated is 0.1-1 MPa, and the rolling speed of the secondary rolling roller group is 5-50 m / min.

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