Nano-zinc oxide filled battery PET (Polyethylene Terephthalate) functional aluminum foil and preparation method thereof
By using nano-zinc oxide filling and room temperature treatment, the problem of micropores in the alumina substrate was solved, improving the density and bonding strength of the alumina substrate and achieving a high-efficiency improvement in battery performance.
Patent Information
- Application Number
- CN202511044878.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-29
- Publication Date
- 2025-10-28
AI Technical Summary
In existing technologies, the alumina underlayer is prone to generating micropores and voids during the film formation process, which leads to a decrease in interfacial adhesion, electrolyte corrosion of aluminum foil and a reduction in mechanical strength. Furthermore, high-temperature sintering and plasma treatment are costly and can easily damage the PET substrate.
The method of using nano zinc oxide filling involves coating the surface of an alumina underlayer with a nano zinc oxide filling liquid, filling the gaps through capillary action, and then treating it at room temperature or low temperature. Combined with aminosilane coupling agents and amino-terminated fluorinated polyimide, the dispersibility and density of the alumina coating are improved.
It significantly improves the density, adhesion strength and corrosion resistance of the alumina underlayer, reduces energy consumption without damaging the PET substrate, and enhances battery performance.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium battery technology, specifically to a battery PET functional aluminum foil filled with nano-zinc oxide and its preparation method. Background Technology
[0002] With the rapid development of the lithium battery industry, people have increasingly higher requirements for lithium batteries. As a key component of lithium batteries, the performance of PET functional aluminum foil directly affects the overall performance of PET functional aluminum foil.
[0003] To improve the bonding strength between PET and aluminum foil, as well as their resistance to electrolyte corrosion, an alumina underlayer is often applied to the PET surface. However, in existing technologies, the alumina underlayer is prone to generating micropores and voids during film formation, leading to the following problems: First, micropores and voids reduce the contact area between the alumina underlayer and PET / aluminum foil, decreasing interfacial adhesion and thus affecting bonding strength; second, electrolytes can easily penetrate into the micropores and voids, corroding the aluminum foil and consequently affecting battery performance; third, stress concentration easily forms at the pores, resulting in decreased mechanical strength.
[0004] To address these issues, high-temperature sintering and plasma treatment are commonly used to fill the micropores and voids in the alumina substrate. However, high-temperature sintering requires a high-temperature environment, which not only consumes a lot of energy and increases costs, but also can cause PET deformation or even damage due to prolonged exposure to high temperatures, affecting battery performance. Plasma treatment is also costly, and improper handling can easily damage the PET substrate, affecting battery performance.
[0005] In summary, solving the above problems and preparing a battery PET functional aluminum foil filled with nano-zinc oxide is of great significance. Summary of the Invention
[0006] The purpose of this invention is to provide a battery PET functional aluminum foil filled with nano zinc oxide and its preparation method, so as to solve the problems mentioned in the background art.
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide includes the following steps: Step 1: Coat the aluminum foil surface with alumina sol, and then perform post-treatment to form the initial alumina underlayer; Step 2: Coat the initial alumina underlayer surface with a nano zinc oxide filler solution, and then perform post-treatment to form an alumina underlayer; thus obtaining PET functional aluminum foil.
[0008] In a more optimized manner, in step 1, the thickness of the initial alumina underlayer is 1~1.5μm; the post-treatment process parameters are: drying temperature of 80~100℃, drying time of 5~10min; heat treatment temperature of 200~250℃, heat treatment time of 15~20min.
[0009] In a more optimized manner, the post-treatment process parameters in step 2 are as follows: standing for 10-15 minutes; drying temperature of 80-100℃ and drying time of 5-10 minutes; heat treatment temperature of 150-180℃ and heat treatment time of 5-10 minutes.
[0010] In a more optimized manner, the preparation process of the alumina sol is as follows: aluminum isopropoxide is added to a solvent, acid is added, and the mixture is stirred for 2-3 hours to obtain the alumina sol.
[0011] In a more optimized manner, the raw materials of the alumina sol include the following components: 10-15 parts by mass of aluminum isopropoxide, 30-50 parts by mass of solvent, and 2-3 parts by mass of acid.
[0012] In a further embodiment, the solvent includes one or both of ethanol and isopropanol; the acid includes one or both of nitric acid and hydrochloric acid.
[0013] In a more optimized manner, the preparation process of the nano-zinc oxide-containing filling solution is as follows: adding nano-zinc oxide to a solvent, adding a silane coupling agent, and ultrasonically dispersing for 20-30 minutes to obtain the nano-zinc oxide-containing filling solution.
[0014] In a more optimized manner, the raw material containing the nano zinc oxide filling liquid includes the following components: 5-8 parts by mass of nano zinc oxide, 30-50 parts by mass of solvent, and 2-5 parts by mass of silane coupling agent.
[0015] In a further embodiment, the solvent includes one or more of deionized water and ethanol; the silane coupling agent includes one or more of γ-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.
[0016] In a more optimized manner, the preparation process of the initial alumina underlayer further includes: S1-1: Under a nitrogen atmosphere, 4,4'-diaminodiphenyl ether is added to N,N-dimethylformamide and stirred at 10~30℃ for 3~5h; 4,4'-(hexafluoroisopropylidene) phthalic anhydride and 4,4'-oxobisphthalic anhydride are added and reacted for 3~5h to obtain an amino-terminated fluorinated polyamic acid solution; then the amino-terminated fluorinated polyamic acid solution is dried at 150~250℃ to obtain an amino-terminated fluorinated polyimide; S1-2: Add aluminum isopropoxide to isopropanol, add acid, stir and react for 2-3 hours, add aminosilane coupling agent and deionized water, react at 30-40℃ for 1-2 hours, then add amino-terminated fluorinated polyimide and N,N-dimethylformamide and ultrasonically disperse for 1-2 hours to obtain alumina sol. S1-3: Alumina sol is coated onto the surface of aluminum foil, followed by post-treatment, acid washing, and water washing to form the initial alumina underlayer.
[0017] In a further embodiment, the pickling is performed using a 5-10 wt% citric acid solution.
[0018] More preferably, the raw material of the amino-terminated fluorinated polyimide includes the following components: by mass parts, 3-5 parts of 4,4'-diaminodiphenyl ether, 50-70 parts of N,N-dimethylformamide, 2-3 parts of 4,4'-(hexafluoroisopropylidene) phthalic anhydride, and 1-2 parts of 4,4'-oxobisphthalic anhydride; The alumina sol comprises the following components by mass: 10-15 parts aluminum isopropoxide, 30-50 parts isopropanol, 2-3 parts acid, 3-4 parts aminosilane coupling agent, 5-8 parts deionized water, 5-7 parts amino-terminated fluorinated polyimide, and 5-8 parts N,N-dimethylformamide.
[0019] In a further embodiment, the aminosilane coupling agent includes one or more of γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.
[0020] Compared with the prior art, the beneficial effects of the present invention are: (1) This solution utilizes capillary action to fill voids, requiring no complex equipment and is simple to operate; (2) This scheme is carried out at room temperature or low temperature during the filling process, which significantly reduces energy consumption; (3) This solution does not damage the PET substrate: the filling liquid is mild and will not damage the PET substrate; (4) The nano zinc oxide in this solution effectively fills the voids in the alumina underlayer, significantly improving the density, bonding strength and corrosion resistance of the underlayer.
[0021] (5) In a further scheme, during the preparation of alumina coating by the traditional sol-gel method, alumina is prone to agglomeration, which affects the performance of the alumina coating. Therefore, this scheme introduces aminosilane coupling agent and amino-terminated fluorinated polyimide into the alumina sol to improve the dispersibility of alumina, enhance the interfacial bonding force, and improve mechanical properties and corrosion resistance.
[0022] Meanwhile, an acid pickling process is added after the initial alumina underlayer is formed because the aminosilane coupling agent is prone to carbonization during heat treatment, affecting the subsequent filling of the nano-zinc oxide-containing filler solution. The proposed solution uses citric acid solution for pickling. This serves two purposes: firstly, it removes the carbonization caused by the aminosilane coupling agent during heat treatment; secondly, it enhances the surface roughness of the initial alumina underlayer, improving the filling efficiency with the subsequent nano-zinc oxide-containing filler solution. It is important to note that the concentration of the citric acid solution should not be too high, as excessively high concentrations can damage the amino-terminated fluorinated polyimide structure, significantly reducing its performance.
[0023] The introduction of amino-terminated fluorinated polyimide has the following advantages: First, the introduction of fluorinated groups provides inert protection to reduce electrolyte wetting, improve chemical stability, and further enhance corrosion resistance. Second, the rigid groups in amino-terminated fluorinated polyimide can increase surface density, thereby improving corrosion resistance. However, too many rigid groups can lead to increased brittleness and an increase in cracks. Therefore, the introduction of flexible segments to balance the rigid groups can prevent crack formation while improving corrosion resistance. Third, the polyimide molecular chain forms a three-dimensional network structure through imide cyclization and micro-crosslinking of fluorinated groups, which improves acid corrosion resistance. Detailed Implementation
[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] It should be noted that the following parts are by weight. There are no special restrictions on the manufacturers of the raw materials involved in this invention. Exemplary examples include: γ-aminopropyltriethoxysilane (CAS number 919-30-2); aluminum isopropoxide (CAS number 555-31-7); nano zinc oxide (size 30nm); γ-glycidyl etheroxypropyltrimethoxysilane (CAS number 2530-83-8); 4,4'-diaminodiphenyl ether (CAS number 101-80-4); 4,4'-(hexafluoroisopropyl)phthalic anhydride (CAS number 1107-00-2); 4,4'-oxydiphthalic anhydride (CAS number 1823-59-2); and γ-aminopropyltriethoxysilane (CAS number 919-30-2).
[0026] Example 1: A method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide, comprising the following steps: Step 1: Preparation of alumina sol: Dissolve 10 parts aluminum isopropoxide in 40 parts ethanol, add 2 parts nitric acid, stir and react for 2 hours to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 80℃ for 10 min, and heat treat at 200℃ for 20 min to form an initial alumina underlayer with a thickness of 1 μm; Step 3: Preparation of nano zinc oxide filling solution: Add 5 parts of nano zinc oxide to 40 parts of ethanol, add 2 parts of γ-aminopropyltriethoxysilane, and disperse by ultrasonication for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 10 min, dry at 80℃ for 10 min, and then heat treat at 150℃ for 10 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0027] Example 2: A method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide, comprising the following steps: Step 1: Preparation of alumina sol: Dissolve 15 parts aluminum isopropoxide in 40 parts isopropanol, add 3 parts hydrochloric acid, stir and react for 3 hours to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 100℃ for 5 min, and heat treat at 250℃ for 15 min to form an initial alumina underlayer with a thickness of 1.5 μm; Step 3: Preparation of nano zinc oxide filling solution: Add 8 parts of nano zinc oxide to 50 parts of deionized water, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and sonicate for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 15 min, dry at 100℃ for 5 min, and then heat treat at 180℃ for 5 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0028] Example 3: A method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide, comprising the following steps: Step 1: (1) Under a nitrogen atmosphere, 4 parts of 4,4'-diaminodiphenyl ether were added to 60 parts of N,N-dimethylformamide and stirred at 20°C for 4 h; 2.5 parts of 4,4'-(hexafluoroisopropylidene) phthalic anhydride and 1.5 parts of 4,4'-oxobisphthalic anhydride were added and reacted for 3-5 h to obtain an amino-terminated fluorinated polyamic acid solution; then the amino-terminated fluorinated polyamic acid solution was dried at 200°C to obtain an amino-terminated fluorinated polyimide; (2) 15 parts of aluminum isopropoxide were added to 40 parts of isopropanol and 3 parts of hydrochloric acid were added and stirred for 2.5 h; 3.5 parts of γ-aminopropyltriethoxysilane and 6.5 parts of deionized water were added and reacted at 35°C for 1.5 h; then 6 parts of amino-terminated fluorinated polyimide and 7 parts of N,N-dimethylformamide were added and ultrasonically dispersed for 1.5 h to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 100℃ for 5 min, heat treat at 250℃ for 15 min, cool, pickle with 8wt% citric acid solution, wash with water to form an initial alumina underlayer with a thickness of 1.6μm; Step 3: Preparation of nano zinc oxide filling solution: Add 8 parts of nano zinc oxide to 50 parts of deionized water, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and sonicate for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 15 min, dry at 100℃ for 5 min, and then heat treat at 180℃ for 5 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0029] Comparative Example 1: Based on Example 1, without filling with filling liquid, and with the other processes unchanged, specifically: Step 1: Preparation of alumina sol: Dissolve 10 parts aluminum isopropoxide in 40 parts ethanol, add 2 parts nitric acid, stir and react for 2 hours to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 80℃ for 10 min, and heat treat at 200℃ for 20 min to form an alumina underlayer with a thickness of 1 μm; thus obtaining PET functional aluminum foil.
[0030] Comparative Example 2: Based on Example 1, the nano-zinc oxide filling solution was adjusted to a different filling solution, while the rest of the process remained unchanged. Specifically: Step 1: Preparation of alumina sol: Dissolve 10 parts aluminum isopropoxide in 40 parts ethanol, add 2 parts nitric acid, stir and react for 2 hours to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 80℃ for 10 min, and heat treat at 200℃ for 20 min to form an initial alumina underlayer with a thickness of 1 μm; Step 3: Preparation of nano-zinc oxide filling solution: 2 parts of γ-aminopropyltriethoxysilane were added to 40 parts of ethanol and ultrasonically dispersed for 30 min to obtain the filling solution; Step 4: Apply the filler liquid to the surface of the initial alumina underlayer, let it stand for 10 minutes, dry it at 80°C for 10 minutes, and then heat treat it at 150°C for 10 minutes to form the alumina underlayer; thus obtaining PET functional aluminum foil.
[0031] Comparative Example 3: Based on Example 3, the alumina sol was made without adding amino-terminated fluorinated polyimide, while keeping the rest of the process unchanged. Specifically: Step 1: Add 15 parts aluminum isopropoxide to 40 parts isopropanol, add 3 parts hydrochloric acid, stir and react for 2.5 h, add 3.5 parts γ-aminopropyltriethoxysilane and 6.5 parts deionized water, react at 35 °C for 1.5 h to obtain alumina sol. Step 2: Coat the aluminum foil surface with alumina sol, dry at 100℃ for 5 min, heat treat at 250℃ for 15 min, cool, pickle with 8wt% citric acid solution, wash with water to form an initial alumina underlayer with a thickness of 1.4μm; Step 3: Preparation of nano zinc oxide filling solution: Add 8 parts of nano zinc oxide to 50 parts of deionized water, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and sonicate for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 15 min, dry at 100℃ for 5 min, and then heat treat at 180℃ for 5 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0032] Comparative Example 4: Based on Example 3, pickling with a high-concentration citric acid solution was used, while the rest of the process remained unchanged. Specifically: Step 1: (1) Under a nitrogen atmosphere, 4 parts of 4,4'-diaminodiphenyl ether were added to 60 parts of N,N-dimethylformamide and stirred at 20°C for 4 h; 2.5 parts of 4,4'-(hexafluoroisopropylidene) phthalic anhydride and 1.5 parts of 4,4'-oxobisphthalic anhydride were added and reacted for 3-5 h to obtain an amino-terminated fluorinated polyamic acid solution; then the amino-terminated fluorinated polyamic acid solution was dried at 200°C to obtain an amino-terminated fluorinated polyimide; (2) 15 parts of aluminum isopropoxide were added to 40 parts of isopropanol and 3 parts of hydrochloric acid were added and stirred for 2.5 h; 3.5 parts of γ-aminopropyltriethoxysilane and 6.5 parts of deionized water were added and reacted at 35°C for 1.5 h; then 6 parts of amino-terminated fluorinated polyimide and 7 parts of N,N-dimethylformamide were added and ultrasonically dispersed for 1.5 h to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 100℃ for 5 min, heat treat at 250℃ for 15 min, cool, pickle with 85wt% citric acid solution, wash with water to form an initial alumina underlayer with a thickness of 1.5μm. Step 3: Preparation of nano zinc oxide filling solution: Add 8 parts of nano zinc oxide to 50 parts of deionized water, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and sonicate for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 15 min, dry at 100℃ for 5 min, and then heat treat at 180℃ for 5 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0033] Comparative Example 5: Based on Example 3, citric acid washing was not used, but the other processes remained unchanged, specifically: Step 1: (1) Under a nitrogen atmosphere, 4 parts of 4,4'-diaminodiphenyl ether were added to 60 parts of N,N-dimethylformamide and stirred at 20°C for 4 h; 2.5 parts of 4,4'-(hexafluoroisopropylidene) phthalic anhydride and 1.5 parts of 4,4'-oxobisphthalic anhydride were added and reacted for 3-5 h to obtain an amino-terminated fluorinated polyamic acid solution; then the amino-terminated fluorinated polyamic acid solution was dried at 200°C to obtain an amino-terminated fluorinated polyimide; (2) 15 parts of aluminum isopropoxide were added to 40 parts of isopropanol and 3 parts of hydrochloric acid were added and stirred for 2.5 h; 3.5 parts of γ-aminopropyltriethoxysilane and 6.5 parts of deionized water were added and reacted at 35°C for 1.5 h; then 6 parts of amino-terminated fluorinated polyimide and 7 parts of N,N-dimethylformamide were added and ultrasonically dispersed for 1.5 h to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 100℃ for 5 min, and heat treat at 250℃ for 15 min to form an initial alumina underlayer with a thickness of 1.8 μm; Step 3: Preparation of nano zinc oxide filling solution: Add 8 parts of nano zinc oxide to 50 parts of deionized water, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and sonicate for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 15 min, dry at 100℃ for 5 min, and then heat treat at 180℃ for 5 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0034] Comparative Example 6: Based on Example 3, without adding an aminosilane coupling agent, and with the rest of the process unchanged, specifically: Step 1: (1) Under a nitrogen atmosphere, 4 parts of 4,4'-diaminodiphenyl ether were added to 60 parts of N,N-dimethylformamide and stirred at 20°C for 4 h; 2.5 parts of 4,4'-(hexafluoroisopropylidene) phthalic anhydride and 1.5 parts of 4,4'-oxobisphthalic anhydride were added and reacted for 3-5 h to obtain an amino-terminated fluorinated polyamic acid solution; then the amino-terminated fluorinated polyamic acid solution was dried at 200°C to obtain an amino-terminated fluorinated polyimide; (2) 15 parts of aluminum isopropoxide were added to 40 parts of isopropanol and 3 parts of hydrochloric acid were added and stirred for 2.5 h; then 6 parts of amino-terminated fluorinated polyimide and 7 parts of N,N-dimethylformamide were added and ultrasonically dispersed for 1.5 h to obtain alumina sol; Step 2: Coat the aluminum foil surface with alumina sol, dry at 100℃ for 5 min, heat treat at 250℃ for 15 min, cool, pickle with 8wt% citric acid solution, wash with water to form an initial alumina underlayer with a thickness of 1.6μm; Step 3: Preparation of nano zinc oxide filling solution: Add 8 parts of nano zinc oxide to 50 parts of deionized water, add 5 parts of γ-glycidyl etheroxypropyltrimethoxysilane, and sonicate for 30 min to obtain nano zinc oxide filling solution. Step 4: Coat the initial alumina underlayer surface with nano zinc oxide filling liquid, let stand for 15 min, dry at 100℃ for 5 min, and then heat treat at 180℃ for 5 min to form the alumina underlayer; obtain PET functional aluminum foil.
[0035] Testing experiments: The PET functional aluminum foils prepared in Examples 1-3 and Comparative Examples 1-6 were tested for the thickness of the alumina underlayer, the surface roughness of the alumina underlayer, the peel strength between the alumina underlayer and PET, and the electrolyte corrosion resistance of the alumina underlayer. The results are shown in Table 1. Table 1
[0036] Results Analysis: According to the data analysis in Table 1, the alumina underlayers prepared in Examples 1-3 of the present invention have lower surface roughness, higher peel strength and longer resistance to electrolyte corrosion, indicating that the alumina underlayers prepared in the present invention have better density, bonding strength and corrosion resistance.
[0037] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.
Claims
1. A method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide, characterized in that: Includes the following steps: Step 1: Coat the aluminum foil surface with alumina sol, and then perform post-treatment to form the initial alumina underlayer; Step 2: Coat the initial alumina underlayer surface with a nano zinc oxide filler solution, and then perform post-treatment to form an alumina underlayer; thus obtaining PET functional aluminum foil.
2. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 1, characterized in that: In step 1, the initial alumina underlayer thickness is 1~1.5μm; the post-treatment process parameters are: drying temperature is 80~100℃, drying time is 5~10min; heat treatment temperature is 200~250℃, heat treatment time is 15~20min.
3. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 1, characterized in that: In step 2, the post-treatment process parameters are as follows: standing for 10-15 minutes; drying temperature of 80-100℃ and drying time of 5-10 minutes; heat treatment temperature of 150-180℃ and heat treatment time of 5-10 minutes.
4. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 1, characterized in that: The preparation process of the alumina sol is as follows: aluminum isopropoxide is added to a solvent, acid is added, and the mixture is stirred for 2-3 hours to obtain alumina sol.
5. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 4, characterized in that: The raw materials of the alumina sol include the following components: by mass, 10-15 parts aluminum isopropoxide, 30-50 parts solvent, and 2-3 parts acid.
6. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 1, characterized in that: The preparation process of the nano-zinc oxide-containing filling solution is as follows: add nano-zinc oxide to the solvent, add silane coupling agent, and ultrasonically disperse for 20-30 minutes to obtain the nano-zinc oxide-containing filling solution.
7. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 6, characterized in that: The raw materials of the nano zinc oxide filling solution include the following components: by mass, 5-8 parts nano zinc oxide, 30-50 parts solvent, and 2-5 parts silane coupling agent.
8. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 1, characterized in that: The preparation process of the initial alumina underlayer also includes: S1-1: Under a nitrogen atmosphere, 4,4'-diaminodiphenyl ether is added to N,N-dimethylformamide and stirred at 10~30℃ for 3~5h; 4,4'-(hexafluoroisopropylidene) phthalic anhydride and 4,4'-oxobisphthalic anhydride are added and reacted for 3~5h to obtain an amino-terminated fluorinated polyamic acid solution; then the amino-terminated fluorinated polyamic acid solution is dried at 150~250℃ to obtain an amino-terminated fluorinated polyimide; S1-2: Add aluminum isopropoxide to isopropanol, add acid, stir and react for 2-3 hours, add aminosilane coupling agent and deionized water, react at 30-40℃ for 1-2 hours, then add amino-terminated fluorinated polyimide and N,N-dimethylformamide and ultrasonically disperse for 1-2 hours to obtain alumina sol. S1-3: Alumina sol is coated onto the surface of aluminum foil, followed by post-treatment, acid washing, and water washing to form the initial alumina underlayer.
9. The method for preparing a battery PET functional aluminum foil filled with nano-zinc oxide according to claim 8, characterized in that: The raw material for the amino-terminated fluorinated polyimide includes the following components: by mass, 3-5 parts of 4,4'-diaminodiphenyl ether, 50-70 parts of N,N-dimethylformamide, 2-3 parts of 4,4'-(hexafluoroisopropylidene) phthalic anhydride, and 1-2 parts of 4,4'-oxobisphthalic anhydride. The alumina sol comprises the following components by mass: 10-15 parts aluminum isopropoxide, 30-50 parts isopropanol, 2-3 parts acid, 3-4 parts aminosilane coupling agent, 5-8 parts deionized water, 5-7 parts amino-terminated fluorinated polyimide, and 5-8 parts N,N-dimethylformamide.
10. The PET functional aluminum foil prepared by the method for preparing nano-zinc oxide-filled battery PET functional aluminum foil according to any one of claims 1 to 9.