A method for preparing composite aluminum film

Abstract

The present invention discloses a method for preparing a composite aluminum film. The method comprises first sandblasting a substrate surface; then spraying a 10-50 μm thick aluminum layer onto the substrate surface using a subsonic flame spraying technique; etching the aluminum layer prepared by thermal spraying in an acid solution to obtain a 4-8 μm aluminum layer; and then transferring the acid-etched aluminum layer to a polymer base film using a transfer technique to obtain the composite aluminum film. The method for preparing the aluminum film has high process controllability, a wide range of thickness selectivity, and excellent performance, thus having broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a method for preparing a composite aluminum film. Background Art

[0002] In recent years, with the rapid development of new energy vehicles, market demand for secondary batteries has gradually increased. Soft-pack lithium-ion batteries, in particular, have become a mainstream market demand due to their advantages such as excellent safety, light weight, high energy density, and long battery life. Research on various aspects of soft-pack batteries has become a hot topic. While the traditional positive electrode material for soft-pack batteries is aluminum foil, batteries using composite aluminum film as the positive electrode material offer increased safety and reduced weight.

[0003] However, the production efficiency of the composite aluminum film prepared at the current stage is low, which greatly restricts the industrialization process of the composite aluminum film. Therefore, it is necessary to provide a method for preparing the composite aluminum film with higher production efficiency to solve the shortcomings of the existing technology. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a method for preparing a composite aluminum film.

[0005] The technical solution adopted by the present invention to achieve the technical purpose is:

[0006] A method for preparing a composite aluminum film comprises the following steps:

[0007] (1) First, the substrate surface is sandblasted;

[0008] (2) Then, a 10-50 μm thick aluminum layer is sprayed on the substrate surface by thermal spraying technology;

[0009] (3) placing the aluminum layer prepared by thermal spraying in an acid solution to etch it to obtain an aluminum layer of 4-8 μm;

[0010] (4) The acid-etched aluminum layer is then transferred to the polymer base film through transfer technology to obtain a composite aluminum film.

[0011] Preferably, the substrate in step (1) is one of aluminum foil and steel strip, and the purpose of the surface treatment is to reduce the bonding between the aluminum layer and the substrate.

[0012] Preferably, the thermal spraying technology described in step (2) can be subsonic flame spraying, with a spraying speed of 1m / s-5m / s and a spraying distance of 20cm-60cm.

[0013] Preferably, the temperature of the acid solution for corrosion in step (3) is 20-60° C., and the time is 1 min-30 min.

[0014] Preferably, the acid solution in step (3) is a 10% dilute hydrochloric acid solution.

[0015] Preferably, the polymer base film described in step (4) can be one of PET, PP or PI.

[0016] Preferably, the above method further comprises cutting the composite aluminum film obtained in step (4) to obtain a finished product.

[0017] More preferably, the composite aluminum film obtained in step (4) is slit and rolled up to obtain aluminum film rolls of different widths and lengths.

[0018] Compared with existing technologies, the present invention offers the following advantages: the adhesion of the composite aluminum layer produced by sandblasting the substrate and then applying subsonic flame spraying can be controlled, resulting in improved density, an adjustable production process, and higher production efficiency. The composite aluminum layer produced by subsonic flame spraying is then thinned to the desired thickness via acid etching, allowing for a wide range of thickness selectivity. Finally, the composite aluminum film is produced through transfer printing, which also requires less demanding polymer films than vacuum-evaporated aluminum films.

[0019] The present invention provides a method for preparing a composite aluminum film. The method has high process controllability for preparing the aluminum film, a wide thickness selectivity for the prepared aluminum film, and excellent performance of the aluminum film, thus having broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a flow chart of the method for preparing composite aluminum film according to the present invention. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the present invention, the present invention is further described in detail below in conjunction with the embodiments. It is understood that the operating steps not specifically described (such as the specific steps of sandblasting and transfer) can be achieved by conventional technical means and are not described in detail in this application.

[0022] Example 1

[0023] Combine Figure 1 , a method for preparing a composite aluminum film, the steps of which are as follows:

[0024] (1) First, the surface of the steel strip is sandblasted.

[0025] (2) Then, a 15 μm thick aluminum layer was sprayed on the surface of the steel strip by subsonic flame spraying technology at a spraying speed of 3 m / s and a spraying distance of 40 cm.

[0026] (3) The aluminum layer prepared by flame spraying was placed in a 10% dilute hydrochloric acid solution for etching at a temperature of 40° C. for 10 min, and then washed and dried to obtain an aluminum layer with a thickness of 8 μm.

[0027] (4) The acid-etched aluminum layer is then transferred to a PET polymer base film using a transfer printing technique to produce a composite aluminum film. Compared to composite aluminum films prepared using existing technologies, the composite aluminum film exhibits a transverse elongation at break of 23%, more than double the elongation at break. The porosity level is also significantly improved, with the number of porosity reduced by approximately 30%. Furthermore, the production time for preparing the aluminum film using the present invention is shortened by 30%.

[0028] (5) Finally, the composite aluminum film is cut into finished products.

[0029] Example 2

[0030] A method for preparing a composite aluminum film, comprising the following steps:

[0031] (1) First, the surface of the steel strip is sandblasted.

[0032] (2) Then, a 50 μm thick aluminum layer was sprayed on the surface of the steel strip by subsonic flame spraying technology at a spraying speed of 1 m / s and a spraying distance of 20 cm.

[0033] (3) The aluminum layer prepared by flame spraying was placed in a 10% dilute hydrochloric acid solution for etching at a temperature of 20° C. for 30 min, and then washed and dried to obtain an aluminum layer with a thickness of 6 μm.

[0034] (4) The acid-etched aluminum layer is then transferred to the PP polymer base film through transfer technology to obtain a composite aluminum film.

[0035] (5) Finally, the composite aluminum film is cut into finished products.

[0036] Example 3

[0037] A method for preparing a composite aluminum film, comprising the following steps:

[0038] (1) First, the surface of the aluminum foil is sandblasted.

[0039] (2) Then, a 10 μm thick aluminum layer was sprayed on the surface of the steel strip by subsonic flame spraying technology at a spraying speed of 5 m / s and a spraying distance of 60 cm.

[0040] (3) The aluminum layer prepared by flame spraying was placed in a 10% dilute hydrochloric acid solution for etching at a temperature of 60° C. for 1 min, and then washed and dried to obtain an aluminum layer with a thickness of 4 μm.

[0041] (4) The acid-etched aluminum layer is then transferred to the PI polymer base film through transfer technology to obtain a composite aluminum film.

[0042] (5) Finally, the composite aluminum film is cut into finished products.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the best embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be covered by the scope of the claims of the present invention.

Claims

1. A method for preparing a composite aluminum film, comprising the following steps: (1) First, the surface of the substrate is sandblasted, and the substrate is one of aluminum foil and steel strip; (2) Then, a 10-50 μm thick aluminum layer is sprayed on the substrate surface by thermal spraying technology, wherein the thermal spraying technology is subsonic flame spraying, the spraying speed is 1 m / s-5 m / s, and the spraying distance is 20 cm-60 cm; (3) The aluminum layer prepared by thermal spraying is placed in an acid solution for etching at a temperature of 20-60°C for 1 min-30 min to obtain an aluminum layer of 4-8 μm. The acid solution is a 10% dilute hydrochloric acid solution. (4) The acid-etched aluminum layer is then transferred to the polymer base film through transfer technology to obtain a composite aluminum film.

2. The method for preparing a composite aluminum film according to claim 1, wherein: The polymer base film described in step (4) is one of PET, PP or PI.

3. A method for preparing a composite aluminum film according to claim 1 or 2, characterized in that: The method also includes cutting the composite aluminum film obtained in step (4) to obtain a finished product.

4. The method for preparing a composite aluminum film according to claim 3, characterized in that: The composite aluminum film obtained in step (4) is cut and rolled to obtain aluminum film rolls of different widths and lengths.

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