Aluminum foil for sodium-ion battery negative electrode current collector

Abstract

This invention discloses an aluminum foil for a negative electrode current collector in sodium-ion batteries, which is prepared by pressing a pre-treated aluminum foil coating with an adhesive. The pre-treated aluminum foil comprises the following percentages of raw materials: Cu: 0.15-0.18%, Fe: 0.50-0.70%, Si: 0.20-0.30%, Mn: ≤0.01%, Mg: ≤0.01%, Ti: ≤0.03%, with the balance being Al and other unavoidable impurity elements. By limiting the types and contents of the components and performing intermediate annealing after rough rolling, internal stress defects generated during rolling are eliminated, effectively improving the uniformity of the alloy structure. After casting, intermediate annealing, and cold rolling, combined with subsequent rolling passes, the dislocation density of the aluminum foil can be increased, thereby solving the problems of easy breakage and difficult processing of lithium battery aluminum foil.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and specifically to an aluminum foil for a negative electrode current collector in sodium-ion batteries. Background Technology

[0002] The rapid development of the power lithium battery industry has led to further development of the aluminum foil industry for power lithium batteries.

[0003] Power lithium batteries have advantages such as high energy density, high working capacity, light weight, small size, low self-discharge, no memory effect, and high cycle life, and are gradually replacing traditional lead-acid batteries.

[0004] Lithium-ion batteries have become ideal energy storage devices due to their advantages such as high operating voltage platform, good rate performance, long service life, high energy density, and low self-discharge rate. However, lithium-ion batteries have unavoidable problems such as lithium resource shortage, uneven distribution, and high cost, and also pose certain safety hazards.

[0005] Compared to lithium, sodium, belonging to the same group, not only possesses similar physical and chemical properties but is also thousands of times more abundant in the Earth's crust. This makes sodium-ion batteries more resource-rich and less expensive than lithium-ion batteries, thus becoming an excellent alternative. However, while using sodium as the anode material can increase the energy density of sodium ions, it also leads to defects such as sodium dendrite growth, volume expansion, and low cycle efficiency during repeated cycles. Unlike lithium, which readily alloys with aluminum-based current collectors at low electrode potentials, sodium anodes do not alloy with aluminum-based current collectors and are commonly used as a current collector in sodium-ion batteries. By reducing the local current density of the aluminum-based current collector in the sodium-ion battery anode, sodium dendrite growth and volume expansion can be suppressed.

[0006] Based on the above market demands, increasingly stringent requirements are being placed on aluminum foil for lithium batteries. As the current collector in lithium batteries, aluminum foil needs sufficient deformation to adapt to the surface characteristics of the active materials during the rolling and flattening process of electrodes coated with graphite and other active materials, preventing deterioration of the contact performance between the aluminum foil and the active materials. If the tensile strength is low, the electrodes coated with active materials are prone to breakage during the rolling and flattening process. Sufficient elongation is also essential. If the elongation is low, the aluminum foil itself will generate internal stress during the rolling and flattening process, leading to cracking and directly affecting battery capacity, cycle life, and other performance characteristics. To meet current market battery performance requirements, commonly used pure aluminum foil for lithium batteries includes alloys such as 1060 and 1050. However, these alloys have quality problems such as relatively soft strength, low elongation, uneven surface roughness, and insufficient surface cleanliness that urgently need to be addressed. Summary of the Invention

[0007] The purpose of this invention is to provide an aluminum foil for a negative electrode current collector in sodium-ion batteries, which solves the problems of current aluminum foils having relatively soft strength, low elongation, and uneven surface roughness.

[0008] The objective of this invention can be achieved through the following technical solutions:

[0009] An aluminum foil for use as a negative electrode current collector in sodium-ion batteries is prepared by the following steps:

[0010] Step S1: Immerse the pretreated aluminum foil in a sodium hydroxide solution at a temperature of 20-25℃ for 2-4 hours, then dry it for later use.

[0011] Step S2: Mix KH560, ethanol, and deionized water evenly, immerse the pretreated aluminum foil in the mixture for 3-5 hours, and then dry it for later use.

[0012] Step S3: Apply adhesive to one side of the pretreated aluminum foil, and then press two pieces of pretreated aluminum foil with the adhesive-coated sides together at a temperature of 70-80℃ to obtain aluminum foil for sodium-ion battery negative electrode current collector.

[0013] Furthermore, the sodium hydroxide solution described in step S1 has a mass fraction of 20%.

[0014] Furthermore, the ratio of KH560, ethanol, and deionized water used in step S2 is 1g:1mL:9mL.

[0015] Furthermore, the pretreated aluminum foil comprises the following percentages of raw materials: Cu: 0.15-0.18%, Fe: 0.50-0.70%, Si: 0.20-0.30%, Mn: ≤0.01%, Mg: ≤0.01%, Ti: ≤0.03%, with the balance being Al and other unavoidable impurity elements.

[0016] Furthermore, the pretreated aluminum foil is prepared by the following steps:

[0017] Step A1: Heat and melt the raw materials at a temperature of 730-740℃ and stir evenly to obtain a mixture.

[0018] Step A2: Cast and roll the mixture to obtain aluminum material;

[0019] Step A3: Cold roll the aluminum material to a thickness of 0.4-0.6 mm, treat it at a temperature of 240-270℃ for 27-35 hours, then roll it to 0.2-0.3 mm and longitudinally shear the edges;

[0020] Step A4: Roll the aluminum foil to 0.013 mm through multiple passes to obtain pretreated aluminum foil.

[0021] Furthermore, the specific steps of the smelting described in step A1 are as follows: under the condition of a temperature of 730°C, a refining agent is added, and the mixture is refined for 20 minutes. Then, the temperature is raised to 740°C, and the mixture is refined for another 20 minutes. After that, the composition is adjusted and the furnace is introduced, with the furnace temperature set at 750°C.

[0022] Furthermore, the refining agent is a chloride salt refining agent, which includes aluminum chloride, zinc chloride, ferric chloride, and manganese chloride.

[0023] Furthermore, in step A2, the temperature of the pre-casting box is 694-704℃, the casting speed is 850-1000mm / min, the casting zone is 55-75mm, the roll surface temperature is ≤75℃, and the thickness of the cast aluminum material is 7.0-8.0mm.

[0024] Furthermore, the multi-pass rolling process described in step A3 is divided into a front pass and a rear pass. The roughness of the work rolls in the front pass is 0.25 μm and the crown is 50%. The roughness of the work rolls in the rear pass is 0.12 μm and the crown is 90%.

[0025] Furthermore, the adhesive is prepared by the following steps:

[0026] Step B1: Sodium dodecylbenzenesulfonate, D4, KH570, and deionized water are mixed and stirred for 3-5 hours at a speed of 150-200 r / min and a temperature of 20-25℃ to obtain a seed solution. The seed solution, D4, KH570, and hexamethyldisiloxane are mixed and reacted for 6-8 hours at a speed of 200-300 r / min and a temperature of 40-50℃ to obtain a polysiloxane core emulsion.

[0027] Step B2: Mix acrylic acid, glycidol, concentrated sulfuric acid, and deionized water evenly, and reflux at 100-105℃ for 6-8 hours to obtain intermediate 1. Mix intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, potassium persulfate, and deionized water, and react at 200-300 r / min and 60-80℃ for 10-15 hours. Adjust the pH of the reaction solution to alkaline to obtain the adhesive.

[0028] The reaction process is as follows:

[0029]

[0030] Furthermore, in step B1, the ratio of sodium dodecylbenzenesulfonate, D4, KH570, and deionized water is 2g:0.01mol:0.01mol:50mL, and the ratio of seed liquid, D4, KH570, and hexamethyldisiloxane is 50mL:0.01mol:0.05mol:0.02mol.

[0031] Further, in step B2, the ratio of acrylic acid, glycidol, and concentrated sulfuric acid is 0.01 mol: 0.01 mol: 20 mL, the mass fraction of concentrated sulfuric acid is 98%, and the ratio of intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, and deionized water is 0.02 mol: 50 mL: 0.03 mol: 0.05 mol: 20 mL. The amount of potassium persulfate is 0.3-0.4% of the reactant mass.

[0032] The beneficial effects of this invention are as follows: By limiting the types and contents of components and performing intermediate annealing after rough rolling, internal stress defects generated during rolling are eliminated, effectively improving the uniformity of the alloy structure. After casting, intermediate annealing, and cold rolling, combined with subsequent rolling passes, the dislocation density of the aluminum foil can be increased. When the grains in the aluminum foil are in a semi-crystalline state, subsequent semi-crystalline annealing and rolling passes can better break and refine the alloy grains of the aluminum foil, thereby improving the tensile strength and ductility of the aluminum foil at extremely fine thicknesses, thus solving the problems of easy breakage and difficult processing of lithium battery aluminum foil. Two pretreated aluminum foils are bonded and pressed together using an adhesive. The adhesive is a polysiloxane emulsion made from D4, KH570, and hexamethyldisiloxane. Acrylic acid and epoxy resin are then esterified to obtain intermediate 1. Intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, and allyl methacrylate are polymerized to form a cross-linked core-shell structure, which can further improve the tensile strength of the aluminum foil. Detailed Implementation

[0033] 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.

[0034] Example 1

[0035] An aluminum foil for use as a negative electrode current collector in sodium-ion batteries is prepared by the following steps:

[0036] Step S1: Immerse the pretreated aluminum foil in a sodium hydroxide solution at 20°C for 2 hours, then dry it for later use.

[0037] Step S2: Mix KH560, ethanol, and deionized water evenly, immerse the pretreated aluminum foil in the mixture for 3 hours, and then dry it for later use.

[0038] Step S3: Apply adhesive to one side of the pretreated aluminum foil, and then press two pieces of pretreated aluminum foil with the adhesive-coated sides together at a temperature of 70°C to obtain aluminum foil for sodium-ion battery negative electrode current collector.

[0039] The pretreated aluminum foil comprises the following percentages of raw materials: Cu: 0.15%, Fe: 0.50%, Si: 0.20%, Mn: 0.002%, Mg: 0.002%, Ti: 0.01%, with the balance being Al and other unavoidable impurity elements.

[0040] The pretreated aluminum foil is prepared by the following steps:

[0041] Step A1: Heat and melt the raw materials at a temperature of 730℃ and stir them evenly to obtain a mixture;

[0042] Step A2: Cast and roll the mixture to obtain aluminum material;

[0043] Step A3: Cold roll the aluminum material to a thickness of 0.4 mm, treat it at a temperature of 240℃ for 27 hours, then roll it to 0.2 mm and longitudinally shear the edges.

[0044] Step A4: Roll the aluminum foil to 0.013 mm through multiple passes to obtain pretreated aluminum foil.

[0045] The specific steps of the smelting described in step A1 are as follows: at a temperature of 730°C, a refining agent is added, and the mixture is refined for 20 minutes. Then, the temperature is raised to 740°C, and the mixture is refined for another 20 minutes. Finally, the composition is adjusted and the furnace is opened, with the furnace temperature set at 750°C.

[0046] The refining agent is a chloride salt refining agent, which includes aluminum chloride, zinc chloride, ferric chloride, and manganese chloride.

[0047] The temperature of the casting and rolling chamber in step A2 is 694℃, the casting and rolling speed is 850mm / min, the casting and rolling zone is 55mm, the roll surface temperature is 70℃, and the thickness of the cast and rolled aluminum material is 7.0mm.

[0048] The multi-pass rolling process described in step A3 is divided into a front pass and a rear pass. The roughness of the work rolls in the front pass is 0.25 μm and the crown is 50%. The roughness of the work rolls in the rear pass is 0.12 μm and the crown is 90%.

[0049] The adhesive is prepared by the following steps:

[0050] Step B1: Sodium dodecylbenzenesulfonate, D4, KH570, and deionized water are mixed and stirred for 3 hours at 150 r / min and 20°C to obtain a seed solution. The seed solution, D4, KH570, and hexamethyldisiloxane are mixed and reacted for 6 hours at 200 r / min and 40°C to obtain a polysiloxane core emulsion.

[0051] Step B2: Mix acrylic acid, glycidol, concentrated sulfuric acid, and deionized water evenly, and reflux at 100°C for 6 hours to obtain intermediate 1. Mix intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, potassium persulfate, and deionized water, and react at 200 r / min and 60°C for 10 hours. Adjust the pH of the reaction solution to alkaline to obtain the adhesive.

[0052] In step B1, the ratio of sodium dodecylbenzenesulfonate, D4, KH570, and deionized water is 2g:0.01mol:0.01mol:50mL, and the ratio of seed liquid, D4, KH570, and hexamethyldisiloxane is 50mL:0.01mol:0.05mol:0.02mol.

[0053] In step B2, the ratio of acrylic acid, glycidol, and concentrated sulfuric acid is 0.01 mol: 0.01 mol: 20 mL, and the mass fraction of concentrated sulfuric acid is 98%. The ratio of intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, and deionized water is 0.02 mol: 50 mL: 0.03 mol: 0.05 mol: 20 mL, and the amount of potassium persulfate is 0.3% of the reactant mass.

[0054] Example 2

[0055] An aluminum foil for use as a negative electrode current collector in sodium-ion batteries is prepared by the following steps:

[0056] Step S1: Immerse the pretreated aluminum foil in a sodium hydroxide solution at 20°C for 4 hours, then dry it for later use.

[0057] Step S2: Mix KH560, ethanol, and deionized water evenly, immerse the pretreated aluminum foil in the mixture for 3-5 hours, and then dry it for later use.

[0058] Step S3: Apply adhesive to one side of the pretreated aluminum foil, and then press two pieces of pretreated aluminum foil with the adhesive-coated sides together at a temperature of 75°C to obtain aluminum foil for sodium-ion battery negative electrode current collector.

[0059] The pretreated aluminum foil comprises the following percentages of raw materials: Cu: 0.0165%, Fe: 0.60%, Si: 0.25%, Mn: 0.006%, Mg: 0.006%, Ti: 0.02%, with the balance being Al and other unavoidable impurity elements.

[0060] The pretreated aluminum foil is prepared by the following steps:

[0061] Step A1: Heat and melt the raw materials at a temperature of 735℃ and stir them evenly to obtain a mixture;

[0062] Step A2: Cast and roll the mixture to obtain aluminum material;

[0063] Step A3: Cold roll the aluminum material to a thickness of 0.5mm, treat it at a temperature of 255℃ for 30 hours, then roll it to 0.26mm and longitudinally shear the edges.

[0064] Step A4: Roll the aluminum foil to 0.013 mm through multiple passes to obtain pretreated aluminum foil.

[0065] The specific steps of the smelting described in step A1 are as follows: at a temperature of 730°C, a refining agent is added, and the mixture is refined for 20 minutes. Then, the temperature is raised to 740°C, and the mixture is refined for another 20 minutes. Finally, the composition is adjusted and the furnace is opened, with the furnace temperature set at 750°C.

[0066] The refining agent is a chloride salt refining agent, which includes aluminum chloride, zinc chloride, ferric chloride, and manganese chloride.

[0067] The temperature of the casting and rolling chamber in step A2 is 699℃, the casting and rolling speed is 850mm / min, the casting and rolling zone is 65mm, the roll surface temperature is 75℃, and the thickness of the cast and rolled aluminum material is 7.5mm.

[0068] The multi-pass rolling process described in step A3 is divided into a front pass and a rear pass. The roughness of the work rolls in the front pass is 0.25 μm and the crown is 50%. The roughness of the work rolls in the rear pass is 0.12 μm and the crown is 90%.

[0069] The adhesive is prepared by the following steps:

[0070] Step B1: Sodium dodecylbenzenesulfonate, D4, KH570, and deionized water are mixed and stirred for 4 hours at 200 r / min and 20°C to obtain a seed solution. The seed solution, D4, KH570, and hexamethyldisiloxane are mixed and reacted for 7 hours at 200 r / min and 45°C to obtain a polysiloxane core emulsion.

[0071] Step B2: Mix acrylic acid, glycidol, concentrated sulfuric acid, and deionized water evenly, and reflux at 103°C for 7 hours to obtain intermediate 1. Mix intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, potassium persulfate, and deionized water, and react at 200 r / min and 70°C for 13 hours. Adjust the pH of the reaction solution to alkaline to obtain the adhesive.

[0072] In step B1, the ratio of sodium dodecylbenzenesulfonate, D4, KH570, and deionized water is 2g:0.01mol:0.01mol:50mL, and the ratio of seed liquid, D4, KH570, and hexamethyldisiloxane is 50mL:0.01mol:0.05mol:0.02mol.

[0073] In step B2, the ratio of acrylic acid, glycidol, and concentrated sulfuric acid is 0.01 mol: 0.01 mol: 20 mL, the mass fraction of concentrated sulfuric acid is 98%, and the ratio of intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, and deionized water is 0.02 mol: 50 mL: 0.03 mol: 0.05 mol: 20 mL. The amount of potassium persulfate is 0.35% of the reactant mass.

[0074] Example 3

[0075] An aluminum foil for use as a negative electrode current collector in sodium-ion batteries is prepared by the following steps:

[0076] Step S1: Immerse the pretreated aluminum foil in a sodium hydroxide solution at 25°C for 4 hours, then dry it for later use.

[0077] Step S2: Mix KH560, ethanol, and deionized water evenly, immerse the pretreated aluminum foil in the mixture for 5 hours, and then dry it for later use.

[0078] Step S3: Apply adhesive to one side of the pretreated aluminum foil, and then press two pieces of pretreated aluminum foil with the adhesive-coated sides together at a temperature of 80°C to obtain aluminum foil for sodium-ion battery negative electrode current collector.

[0079] The pretreated aluminum foil comprises the following percentages of raw materials: Cu: 0.18%, Fe: 0.70%, Si: 0.30%, Mn: 0.01%, Mg: 0.01%, Ti: 0.03%, with the balance being Al and other unavoidable impurity elements.

[0080] The pretreated aluminum foil is prepared by the following steps:

[0081] Step A1: Heat and melt the raw materials at a temperature of 740℃ and stir them evenly to obtain a mixture;

[0082] Step A2: Cast and roll the mixture to obtain aluminum material;

[0083] Step A3: Cold roll the aluminum material to a thickness of 0.6 mm, treat it at a temperature of 270℃ for 35 hours, then roll it to 0.3 mm and longitudinally shear the edges.

[0084] Step A4: Roll the aluminum foil to 0.013 mm through multiple passes to obtain pretreated aluminum foil.

[0085] The specific steps of the smelting described in step A1 are as follows: at a temperature of 730°C, a refining agent is added, and the mixture is refined for 20 minutes. Then, the temperature is raised to 740°C, and the mixture is refined for another 20 minutes. Finally, the composition is adjusted and the furnace is opened, with the furnace temperature set at 750°C.

[0086] The refining agent is a chloride salt refining agent, which includes aluminum chloride, zinc chloride, ferric chloride, and manganese chloride.

[0087] The temperature of the casting and rolling chamber in step A2 is 704℃, the casting and rolling speed is 1000mm / min, the casting and rolling zone is 75mm, the roll surface temperature is 75℃, and the thickness of the cast and rolled aluminum material is 8.0mm.

[0088] The multi-pass rolling process described in step A3 is divided into a front pass and a rear pass. The roughness of the work rolls in the front pass is 0.25 μm and the crown is 50%. The roughness of the work rolls in the rear pass is 0.12 μm and the crown is 90%.

[0089] The adhesive is prepared by the following steps:

[0090] Step B1: Sodium dodecylbenzenesulfonate, D4, KH570, and deionized water are mixed and stirred for 5 hours at 200 r / min and 25°C to obtain a seed solution. The seed solution, D4, KH570, and hexamethyldisiloxane are mixed and reacted for 8 hours at 300 r / min and 50°C to obtain a polysiloxane core emulsion.

[0091] Step B2: Mix acrylic acid, glycidol, concentrated sulfuric acid, and deionized water evenly, and reflux at 105°C for 8 hours to obtain intermediate 1. Mix intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, potassium persulfate, and deionized water, and react at 300 r / min and 80°C for 15 hours. Adjust the pH of the reaction solution to alkaline to obtain the adhesive.

[0092] In step B1, the ratio of sodium dodecylbenzenesulfonate, D4, KH570, and deionized water is 2g:0.01mol:0.01mol:50mL, and the ratio of seed liquid, D4, KH570, and hexamethyldisiloxane is 50mL:0.01mol:0.05mol:0.02mol.

[0093] In step B2, the ratio of acrylic acid, glycidol, and concentrated sulfuric acid is 0.01 mol: 0.01 mol: 20 mL, the mass fraction of concentrated sulfuric acid is 98%, and the ratio of intermediate 1, polysiloxane core emulsion 1, 4-butanediol diacrylate, allyl methacrylate, and deionized water is 0.02 mol: 50 mL: 0.03 mol: 0.05 mol: 20 mL. The amount of potassium persulfate is 0.4% of the reactant mass.

[0094] Comparative Example 1

[0095] The aluminum foil in this comparative example contains the following percentages of raw materials: Si: 0.08%, Fe: 0.18%, Cu: 0.02%, Mn: 0.01%, Zn: 0.02%, Ti: 0.03%, with the balance being Al.

[0096] Comparative Example 2

[0097] The aluminum foil in the benzene comparative example contains the following percentages of raw materials: Si: 0.12%, Fe: 0.23%, Cu: 0.03%, Mn: 0.015%, Zn: 0.03%, Ti: 0.025%, with the balance being Al.

[0098] The aluminum foils prepared in Examples 1-3 and Comparative Examples 1-2 were pressed into 0.012 mm samples and subjected to tensile strength and ductility tests. The test results are shown in the table below.

[0099]

[0100] As shown in the table above, the aluminum foils prepared in Examples 1-3 have a tensile strength of 272-281 MPa and an elongation of 6.32-6.62%, indicating that the present invention has excellent tensile strength and elongation.

[0101] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. An aluminum foil for a negative electrode current collector in a sodium-ion battery, characterized in that: It is made by the following steps: Step S1: Immerse the pretreated aluminum foil in sodium hydroxide solution at a temperature of 20-25℃ for 2-4 hours, then dry it for later use. Step S2: Mix KH560, ethanol, and deionized water thoroughly, and then immerse the pretreated aluminum foil in the mixture. Soak for 3-5 hours, then dry and set aside. Step S3: Apply adhesive to one side of the pretreated aluminum foil, and then press two pieces of pretreated aluminum foil with the adhesive-coated sides together at a temperature of 70-80℃ to obtain aluminum foil for sodium-ion battery negative electrode current collector. The pretreated aluminum foil comprises the following percentages of raw materials: Cu: 0.15-0.18%, Fe: 0.50-0.70%, Si: 0.20-0.30%, Mn: ≤0.01%, Mg: ≤0.01%, Ti: ≤0.03%, with the balance being Al and other unavoidable impurity elements; The pretreated aluminum foil is prepared by the following steps: Step A1: Heat and melt the raw materials at a temperature of 730-740℃ and stir evenly to obtain a mixture. Step A2: Cast and roll the mixture to obtain aluminum material; Step A3: Cold roll the aluminum material to a thickness of 0.4-0.6 mm, treat it at a temperature of 240-270℃ for 27-35 hours, then roll it to 0.2-0.3 mm and longitudinally shear the edges; Step A4: Roll the aluminum foil to 0.013 mm through multiple rolling passes to obtain pretreated aluminum foil; The specific steps of the smelting described in step A1 are as follows: at a temperature of 730°C, a refining agent is added, and the mixture is refined for 20 minutes. Then, the temperature is raised to 740°C, and the mixture is refined for another 20 minutes. After that, the composition is adjusted and the furnace is opened. The furnace temperature is 750°C. The refining agent is a chloride salt refining agent, which includes aluminum chloride, zinc chloride, ferric chloride, and manganese chloride; The temperature of the casting and rolling chamber in step A2 is 694-704℃, the casting and rolling speed is 850-1000mm / min, the casting and rolling zone is 55-75mm, the roll surface temperature is ≤75℃, and the thickness of the cast and rolled aluminum material is 7.0-8.0mm. The multi-pass rolling process described in step A4 is divided into a front pass and a rear pass. The roughness of the work rolls in the front pass is 0.25 μm and the crown is 50%. The roughness of the work rolls in the rear pass is 0.12 μm and the crown is 90%. The adhesive is prepared by the following steps: Step B1: Sodium dodecylbenzenesulfonate, D4, KH570 and deionized water are mixed and stirred to prepare seed solution. The seed solution, D4, KH570 and hexamethyldisiloxane are mixed and reacted to prepare polysiloxane core emulsion. Step B2: Acrylic acid, glycidol, concentrated sulfuric acid and deionized water are mixed and refluxed to obtain intermediate 1. Intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, potassium persulfate and deionized water are mixed and reacted. The pH of the reaction solution is adjusted to be alkaline to obtain the binder. The ratio of sodium dodecylbenzenesulfonate, D4, KH570, and deionized water in step B1 is 2g:0.01mol:0.01mol:50mL, and the ratio of seed liquid, D4, KH570, and hexamethyldisiloxane is 50mL:0.01mol:0.05mol:0.02mol. In step B2, the ratio of acrylic acid, glycidol, and concentrated sulfuric acid is 0.01 mol: 0.01 mol: 20 mL, the mass fraction of concentrated sulfuric acid is 98%, and the ratio of intermediate 1, polysiloxane core emulsion, 1,4-butanediol diacrylate, allyl methacrylate, and deionized water is 0.02 mol: 50 mL: 0.03 mol: 0.05 mol: 20 mL. The amount of potassium persulfate is 0.3-0.4% of the reactant mass.

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