Preparation method of functional film for calendering solid-state battery lithium strip

Abstract

The invention discloses a preparation method of a functional film for solid-state battery lithium strip rolling, and belongs to the technical field of battery lithium strip rolling. Comprising the following steps: S1, preparing a basic film material; s2, coating the basic film material in the step S1 with a functional coating; s3, drying and curing the film material coated with the functional coating in the step S2; s4, rolling the thin film material dried and cured in the step S3; and S5, detecting and warehousing the film material. According to the preparation method, a film with a functional coating can be prepared, the lithium strip can be completely isolated from the surface of a metal roller in the density increasing and thinning process of the lithium strip by using the product, and roller surface residual lithium materials can be effectively prevented from occurring in the pressure rolling process of the lithium strip and the metal roller and when the lithium strip is separated from the surface of the metal roller for film discharging; and the roller surface can be continuously produced for a long time without any lithium strip material residue, so that the risk of breakage of the lithium strip is prevented.

Description

Technical Field

[0001] The invention provides a method for preparing a functional film for rolling a solid-state battery lithium ribbon, belonging to the technical field of battery lithium ribbon rolling. Background Art

[0002] In recent years, the safety and range issues of traditional batteries, especially their flammability, have caused many casualties and have become core issues that need to be addressed urgently. The development of solid-state batteries is the future trend, and its core technologies have gradually made breakthroughs. However, one of the most critical core technologies, lithium ribbon calendering, has not yet developed a safe and efficient production process. According to the physical and chemical properties of lithium ribbons, the calendering process for increasing density and thinning has extremely strict requirements on the materials in contact, including surface moisture treatment of the material, surface flatness during the calendering process for increasing density and thinning and after de-rolling, surface integrity, and surface special requirements that are conducive to the next step of lamination and assembly with metal materials (such as copper foil). Initial attempts at metal-to-roll direct calendering can increase the density and thinning of lithium ribbons, but during the process, the lithium ribbon surface is continuously pressurized and contacted with the metal rollers for de-molding. After the lithium ribbon is increased in density and thinned, residual lithium ribbon material will appear on the roller surface when it is de-rolled, resulting in surface defects of the lithium ribbon, affecting product performance and appearance, and causing the material performance to fail to meet the designed performance and efficiency requirements. In response to the above problems, it is necessary to prepare a functional film for solid-state battery lithium ribbon calendering to solve the above problems. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a technical solution: a method for preparing a functional film for rolling a solid-state battery lithium strip, comprising the following steps: S1, preparing a basic film material; S2, applying a functional coating to the basic film material in step S1; S3, drying and curing the film material after applying the functional coating in step S2; S4, winding up the film material dried and cured in step S3; S5, inspecting and storing the film material.

[0004] As an improvement, in step S1, the base film can be made of PET, PC, PP, or PE film materials, with a thickness of 3 μm to 250 μm and colors such as transparent, red, blue, yellow, green, and black.

[0005] As an improvement, the raw materials of the functional coating in step S2 are composed of five solvent materials: silicone oil, anti-sticking agent, cross-linking agent, anchoring agent, platinum catalyst, and ethyl acetate, mixed in a designed ratio of 1:0.01:0.005::0.005:0.005:5.

[0006] As an improvement, in step S2, a multi-roller transfer device in a precision coating machine is used to evenly coat the mixed liquid on the base film.

[0007] As improved, in steps S3, S4, the product is obtained by drying and curing through the drying device of the precision coater, and cooling through the cooling device of the precision coater and then winding.

[0008] As improved, in step S3, the temperature of the drying device is 90-160°C, the length of the oven is about 30 meters, and the thickness of the dried surface functional coating is 1-10 microns.

[0009] The beneficial effects of the present application are as follows:

[0010] Using the product of the present application, in the process of increasing the density and thinning the lithium ribbon, as a direct lithium ribbon adhering material and a carrier, the contact between the lithium ribbon and the metal roller surface can be completely isolated, the residual lithium material on the roller surface during the process of pressing and calendering of the lithium ribbon and the film separation from the metal roller surface can be effectively prevented, the surface defects caused by the delamination of the lithium material can be prevented, the lithium ribbon surface can be continuously produced without any residual lithium material for a long time, the risk of lithium ribbon breakage can be prevented, the roller surface does not need to be cleaned during shutdown, the surface of the prepared high-density lithium ribbon product is flat and defect-free, and after being adhered to a metal thin film (such as a copper foil) product, the surface is flat and defect-free. The product can also be used as a carrier to protect the product to the next process, and after the completion of the next process, it can be easily peeled off. The surface of the lithium ribbon after peeling is flat and beautiful, and the product quality, performance and production efficiency can be significantly and effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The flowchart of the present application.

[0012] Figure 2 The product structure diagram of the present application.

[0013] Figure 3-6 The finished product diagram of the present application.

[0014] 1, functional coating; 2, base film material layer. DETAILED DESCRIPTION

[0015] The present application will be further described below with reference to the accompanying drawings.

[0016] According to Figure 1-6 As shown in the figure: the present application provides a preparation method of a functional film for solid-state battery lithium ribbon calendering: comprising the following steps: S1, preparing a base film material; S2, coating a functional coating on the base film material in step S1; S3, drying and curing the film material after coating the functional coating in step S2; S4, winding the film material dried and cured in step S3; S5, detecting the film material into the warehouse.

[0017] In step S1, the base film can be selected from PET, PC, PP and PE film materials, and the thickness of the base film is 3-250 microns, and the color can be selected from transparent, red, blue, yellow, green and black.

[0018] The functional coating in step S2 is made from a mixture of five solvent materials: silicone oil, an anti-sticking agent, a cross-linking agent, an anchoring agent, a platinum catalyst, and ethyl acetate, mixed in a designed ratio of 1:0.01:0.005:0.005:0.005:5. Leveraging the slightly viscous nature of the silicone oil, the anti-sticking agent is blended with the cross-linking agent, anchoring agent, and platinum catalyst in the designed ratios to achieve the desired curing efficiency, hardness, and adhesion. Ethyl acetate acts as a diluent to evenly disperse the various materials and achieve the desired leveling properties.

[0019] In step S2, the mixed liquid is evenly coated on the base film using a multi-roll transfer device in a precision coating machine. In steps S3 and S4, the mixed liquid is dried and solidified by a drying device of the precision coating machine, and then cooled and rolled up by a cooling device of the precision coating machine to obtain the product of the present invention, such as Figure 2 As shown, the bottom is the basic film material layer 2, and the top is the coated functional coating 1; Figure 3-6 This is a physical diagram of the finished product obtained by the present invention. In step S3, the temperature of the drying device is 90°C-160°C, the oven length is about 30 meters, and the thickness of the surface functional coating after drying is 1μm-10μm. The use of a precision coating machine can conveniently control the curing temperature and curing efficiency. Through the ratio of coating materials and the reasonable design of curing temperature and curing speed, the surface functional coating is made uniform and smooth, with moderate hardness and softness. The surface is not slightly sticky when not under pressure, and is used for the calendering process of lithium strip materials with different densities and surface energies.

[0020] The product of the present invention does not produce stickiness when it comes into natural contact with the lithium strip. After contact, it can move in multiple directions to check the calendering position. It produces micro-stickiness and degassing when entering the metal roller for pressure bonding and calendering. The functional coating surface of the product of the present invention and the surface of the lithium strip can form a perfect surface bond during pressure bonding and calendering, and can meet the ductility requirements of the lithium strip during calendering, preventing the lithium strip material from wrinkling at the moment of calendering. The product of the present invention will not produce sticking after long-term bonding with the lithium strip material, and can be easily peeled off at any time. Compared with direct calendering of metal rollers and calendering of metal carrier strips through metal rollers, there is no need to stop the machine to clean the roller surface. No lithium strip material residue can be produced continuously for a long time, so that the surface of the lithium strip is flat and defect-free. It can be easily peeled off at any time after long-term bonding, and the production speed is at least doubled. It is safe and efficient, and has obvious technical advantages.

[0021] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a functional film for rolling a solid-state battery lithium ribbon, characterized in that: The following steps are involved: S1. Prepare basic film materials; S2, applying a functional coating onto the base film material in step S1; S3, drying and curing the thin film material after coating the functional coating in step S2; S4, rolling up the film material dried and solidified in step S3; S5, inspecting and storing the film material.

2. The method for preparing a functional film for solid-state battery lithium ribbon rolling according to claim 1, characterized in that: In step S1, the base film can be made of PET, PC, PP, or PE film materials. The thickness of the base film is 3 μm-250 μm, and the color can be transparent, red, blue, yellow, green, or black.

3. The method for preparing a functional film for solid-state battery lithium ribbon rolling according to claim 1, characterized in that: The raw materials of the functional coating in step S2 are composed of five solvent materials: silicone oil, anti-sticking agent, cross-linking agent, anchoring agent, platinum catalyst, and ethyl acetate, which are mixed in a designed ratio of 1:0.01:0.005::0.005:0.005:

5.

4. The method for preparing a functional film for rolling a solid-state battery lithium ribbon according to claim 3, characterized in that: In step S2, the mixed liquid is evenly coated on the base film using a multi-roll transfer device in a precision coating machine.

5. The method for preparing a functional film for solid-state battery lithium ribbon rolling according to claim 1, characterized in that: In steps S3 and S4, the product of the present invention is obtained by drying and curing the product through the drying device of the precision coater, and then cooling the product through the cooling device of the precision coater and then winding the product.

6. The method for preparing a functional film for solid-state battery lithium ribbon rolling according to claim 5, characterized in that: In step S3, the temperature of the drying device is 90°C-160°C, the length of the oven is about 30 meters, and the thickness of the surface functional coating after drying is 1 μm-10 μm.

Images