High-toughness battery aluminum foil and preparation method thereof

Abstract

The invention provides a high-toughness battery aluminum foil and a preparation method thereof, and belongs to the technical field of aluminum alloy materials.The preparation method comprises the following steps that pretreated graphene powder is added into a nickel-containing mixed solution to be subjected to ultrasonic treatment and drying, and nickel-coated graphene particles are obtained; adding the porous carbon coated CeO2 hollow spheres into an aqueous solution containing 2-mercaptobenzoxazole and Zn (NO3) 2, mixing, stirring, centrifuging, drying, adding into an ethanol solution, and carrying out ultrasonic dispersion to obtain a C-coated CeO2 / Zn-MBO dispersion liquid; the preparation method comprises the following steps: in an inert gas environment, melting an aluminum ingot and recycled aluminum foil, standing, refining, adding nickel-coated graphene particles and an Al-Ti-B-Ce grain refiner, stirring, degassing, deslagging, filtering, continuously casting and rolling, cold-rolling, immersing into a C-coated CeO2 / Zn-MBO dispersion liquid, and carrying out foil rolling, slitting and back-rolling to obtain the high-toughness battery aluminum foil. According to the invention, recycling and high toughness of the waste aluminum foil can be realized, and good electrochemical corrosion resistance is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy materials, in particular to a high-strength and high-toughness battery aluminum foil and a preparation method thereof. BACKGROUND

[0002] Aluminum foils for lithium-ion batteries are divided into current collectors, outer packaging aluminum plastic films, and tabs. The positive electrode current collector, which is commonly referred to as battery aluminum foil, is used in large quantities. Its main function is to support the positive electrode material, collect the positive electrode current, and ensure the smooth processing of the positive electrode. Its performance and quality affect the charging and discharging efficiency and service life of the battery.

[0003] Battery aluminum foil is a high-end precision processing product in the aluminum foil industry. Due to its special use conditions, it has very strict requirements for various technical indicators. With the continuous development of battery technology and the increasing demand for battery safety performance, the mechanical strength of the current collector battery aluminum foil is also continuously improved. When the strength reaches a certain level, it is difficult to guarantee the required elongation. In the prior art, to solve the problems of large mechanical property fluctuations and low tensile strength of the produced battery foil, measures such as increasing the content of alloying elements, increasing the rolling passes and cold deformation are often used. However, increasing the content of elements such as Mn and Mg can effectively improve the tensile strength, but it will also increase the resistivity and reduce the elongation, which will adversely affect the overall performance of the battery foil.

[0004] In addition, with the rapid increase in demand for lithium-ion batteries, the overexploitation of aluminum resources, the continuous increase in energy consumption, and the pollution problems caused by waste lithium-ion batteries to the environment have gradually become a bottleneck restricting the development of the industry. As an important component of lithium batteries, the production process of aluminum foil not only consumes a large amount of natural resources, but also has a negative impact on the environment. If the treatment and recycling of aluminum foil and other materials in waste lithium-ion batteries cannot be effectively solved, it will cause more serious burden to the environment.

[0005] At the same time, since the battery aluminum foil is often exposed to the action of electrolyte and current, its surface is prone to electrochemical corrosion. The electrochemical corrosion process is usually accompanied by the charging and discharging cycle of the battery, especially in a strong acidic or alkaline environment. In this environment, the battery aluminum foil is prone to react with the components in the electrolyte, forming corrosion products. These products not only affect the contact between the metal surface and the electrode, but also can cause problems such as internal short circuit and capacity decay of the battery, thereby affecting the cycle life and safety of the battery.

[0006] Therefore, it is necessary to provide a high-strength and high-toughness battery aluminum foil and a preparation method thereof to solve the problems existing in the prior art. SUMMARY

[0007] Therefore, the application provides a high-toughness battery aluminum foil and a preparation method thereof, which can realize recycling of waste aluminum foil and high toughness, and has good electrochemical corrosion resistance.

[0008] To achieve the above-mentioned purpose, the application provides a preparation method of a high-toughness battery aluminum foil, which comprises the following steps: S1, adding the pretreated graphene powder into a nickel-containing mixed solution for ultrasonic treatment, filtering to obtain a precipitate, and vacuum drying to obtain nickel-coated graphene particles; S2, adding the porous carbon-wrapped CeO2 hollow spheres into an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2 for mixing and stirring, centrifuging, washing, vacuum drying, and adding into an ethanol solution for ultrasonic dispersion to obtain a C@CeO2 / Zn-MBO dispersion solution; S3, placing aluminum ingots and recycled aluminum foil into a graphite crucible for melting under an inert gas environment, transferring to a holding furnace for standing, refining, adding the nickel-coated graphene particles and Al-Ti-B-Ce grain refiner for stirring, degassing and deslagging, filtering, continuous casting and rolling, cold rolling, immersing into the C@CeO2 / Zn-MBO dispersion solution for treatment, and then performing foil rolling, slitting, and reverse rolling to obtain the high-toughness battery aluminum foil.

[0009] The application can significantly improve the mechanical properties of the aluminum alloy by adding the nickel-coated graphene particles as a solid lubricant, and endow the aluminum alloy with high toughness. The nickel-coated graphene particles can significantly improve the toughness and tensile strength of the battery aluminum foil. The strengthening effect of the graphene mainly lies in the strong carbon-carbon bond structure, and as the toughest two-dimensional material, the graphene has high tensile strength, which not only improves the tensile strength of the overall material, but also enhances the anti-fatigue crack propagation ability. In addition, the addition of the nickel-coated graphene can increase the wettability of the graphite particles during the dispersion process, and the nickel coating layer forms intermetallic compounds (such as Al3Ni) at the interface between the graphene and the aluminum matrix, significantly enhancing the interface bonding force and making the overall material more dense. In addition, the high aspect ratio graphene sheets can pin the grain boundaries to refine the aluminum grains, realize fine-grain strengthening, and reduce stress concentration, thereby improving the overall toughness. The addition of the graphene in the aluminum foil can improve the overall electrical conductivity, and the nickel-coated graphene composite material has a relatively uniform structure and good interface bonding, which can more effectively reduce the resistance, improve the current conduction efficiency, and further improve the overall electrical conductivity.

[0010] The Al-Ti-B-Ce grain refiner is added in the application, wherein TiB2 is the core component of aluminum alloy grain refinement. During the solidification process after the melting of the aluminum alloy, the TiB2 particles can promote the nucleation of aluminum atoms in the liquid phase as the core of heterogeneous nucleation, thereby refining the grains; the particle size of TiB2 is usually small, and they can provide a large number of nucleation sites, so that the grains of the aluminum alloy become smaller during the solidification process. In addition, the rare earth element Ce in the Al-Ti-B-Ce grain refiner can be used as a surfactant to improve the fluidity of the melt, hinder the agglomeration and sedimentation of the second phase particles, promote the uniform nucleation of the alpha-Al matrix, and further improve the overall tensile strength and elongation.

[0011] The application utilizes the abundant active sites on the surface of CeO2 and the porous carbon-coated CeO2 hollow spheres (C@CeO2), and the high surface area provided by the porous structure to load zinc ions and 2-mercapto-benzoxazole (MBO), to prepare C@CeO2 / Zn-MBO; wherein the zinc ions and MBO have a significant adsorption and interaction effect, especially under different pH conditions, the release of zinc ions is triggered by the change in pH, and these released substances form cathode and anode sites at the metal interface, providing active inhibition, the redox properties of the external CeO2 are combined with the corrosion inhibition effect of zinc ions to form a stable passivation film, and MBO forms a stronger corrosion inhibition film on the metal surface by the combined action of the mercapto group and nitrogen atom in the molecule and zinc ions, enhancing the release effect of zinc ions, thereby synergistically playing a corrosion inhibition effect and enhancing the electrochemical corrosion resistance of the battery aluminum foil material. In addition, the external porous carbon layer can form a continuous conductive path to avoid affecting the conductivity of the overall material.

[0012] Optionally, the pretreated graphene powder is obtained by immersing the graphene powder in an acetone solution, ultrasonic treatment at 40 DEG C for 30 min, filtering to obtain a precipitate, adding to distilled water at 50-60 DEG C, stirring for 20-40 min, filtering to obtain a precipitate, immersing in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonic treatment for 20-30 min, filtering to obtain a precipitate, repeatedly washing with distilled water for 3-5 times, and drying to obtain the graphene powder.

[0013] The pretreatment of the graphene powder is performed in the application, and the treatment with hydrofluoric acid is helpful to change the surface wettability of the graphene.

[0014] Optionally, the ultrasonic treatment in step S1 is performed under constant ultrasonic oscillation at a temperature of 40 DEG C, a frequency of 25 kHz, and a power of 250 W, for 1-3 h, and the vacuum drying is performed for 12-18 h.

[0015] Optionally, the porous carbon-coated CeO2 hollow sphere is prepared by dissolving cerium nitrate hexahydrate and citric acid monohydrate in deionized water, stirring at room temperature for 4 hours, and then placing under microwave conditions of 95-130 W and 150 DEG C for 2 minutes, and then cooling, filtering, washing, and drying, and then annealing under an argon atmosphere at 600 DEG C for 1 hour.

[0016] The present application uses citric acid monohydrate as a carbon precursor by a microwave hydrothermal method. 3+ The citric acid monohydrate is complexed with Ce 3+ oxide to form a CeO2 core under an argon atmosphere, and the citric acid monohydrate is carbonized to form a porous carbon shell, thereby forming a core-shell structure.

[0017] Optionally, in the step S2, the speed of the mixing and stirring is 100 r / min, the time is 16-24 hours, the speed of the centrifugation is 700 r / min, the time is 5-8 minutes, the deionized water is used for washing 5 times, the temperature of the vacuum drying is 65 DEG C, the time is 12-18 hours, and the time of the ultrasonic dispersion is 30 minutes.

[0018] Optionally, the Al-Ti-B-Ce grain refiner is prepared by placing aluminum titanium boron wires and stearic acid in a ball mill under an argon atmosphere, ball milling at a speed of 150 r / min for 30-50 minutes, adding cerium dioxide powder and continuing to ball mill for 30-50 minutes, placing in an extrusion die, cold pressing at 500 MPa for 20-30 minutes, heating to 500 DEG C and maintaining for 30-50 minutes, and extruding at an extrusion ratio of 30:1, and then slowly cooling.

[0019] The Al-Ti-B-Ce grain refiner is prepared by a combination of cold pressing and hot extrusion, the ball milling is used to effectively disperse and refine aggregates in the matrix, thereby increasing the number of nucleated particles, the cold pressing is used to densify the powders, the hot pressing and high extrusion ratio are used to make the metallurgical bonding between the powders more compact, and the refining effect is improved.

[0020] Optionally, the recovered aluminum foil is obtained by disassembling the battery, separator, cathode electrode and anode electrode after discharging the cylindrical battery to 0.1V, washing the electrodes with dimethyl carbonate, cutting the double-sided electrodes into small pieces, placing the cathode electrode into a glycerol-triacetate solvent, stabilizing the temperature at 100℃, stirring under ultrasonic treatment for 30-50min, cooling to room temperature, manually separating the aluminum foil, rinsing with ethanol, and centrifuging at 90-150℃ for 5min to separate the upper polyvinylidene fluoride residue, and then drying.

[0021] The present application recovers aluminum foil from waste batteries by using bio-based solvent glycerol-triacetate combined with ultrasonic treatment technology, realizes the recycling of waste materials and reduces the pollution to the environment. By simply immersing the used electrode in the glycerol-triacetate solvent at a relatively low temperature combined with ultrasonic treatment technology, the electrode material can be completely stripped from the aluminum foil within a few minutes without causing corrosion to the aluminum foil. As a polar solvent, glycerol-triacetate has good surface activity, which increases the contact area of the solvent and the solid surface by reducing the contact angle, thereby enhancing the wettability of Al and the cathode film surface, allowing glycerol-triacetate to penetrate or pass through the Al / cathode film interface, further promoting stripping; in addition, the glycerol-triacetate solvent destroys the bonding between the polyvinylidene fluoride binder and the Al current collector through a competitive inhibition mechanism, and the polyvinylidene fluoride binder can be quickly dissolved and separated in the glycerol-triacetate solvent at above 80℃ to improve the purity of the recovered aluminum foil.

[0022] Optionally, in the step S3, the aluminum ingot and the recovered aluminum foil are placed in a graphite crucible under an argon atmosphere, melted at 720-750℃ under electromagnetic stirring, then transferred to a holding furnace at 750℃ and left for 10min, and subjected to 3 times of refining treatment, each time for 20-30min, with an interval of 2.5-4h, and after refining, the surface dross is removed, and nickel-coated graphene particles and Al-Ti-B-Ce grain refiner are added for continuous stirring at a speed of 700r / min for 10-20min; continuous casting and rolling are carried out under the conditions of a melt temperature of 700℃ in the front box and a casting and rolling speed of 960mm / min, and the liquid aluminum alloy melt is cast and rolled into a cast and rolled blank in the casting and rolling area.

[0023] Specifically, the thickness of the cast and rolled blank is 6.8-7.2mm.

[0024] The present application melts under electromagnetic stirring, which is a non-contact physical stirring, can realize the automation of melt stirring, ensure the uniformity of the composition and temperature of the aluminum melt, and reduce the metal burning loss.

[0025] Preferably, the degassing and deslagging is carried out at 750 DEG C, and high-purity argon gas is introduced at a flow rate of 25 L / min to degas the melt, and the dross floating to the surface of the melt with the argon bubbles is removed every 1 h; the filtering treatment is carried out by using a tubular filter and a plate filter system, and the filtering mesh number is 50 mesh and 60 mesh; During the refining and degassing and deslagging, the purity and structure of the aluminum alloy are optimized by removing the impurities and gases in the alloy, and the defects in the aluminum alloy are reduced, so that the strength and toughness of the aluminum alloy are further improved.

[0026] Optionally, in the step S3, the cold rolling is carried out under the conditions that the hardness of the work roll is 90-95 HSD, the roughness is 0.12 um, and the convexity is 0.09 mm, the foil rolling blank is obtained after 6 passes of rolling, the foil rolling blank is immersed in a mixed solution of acetone / ethanol for ultrasonic cleaning for 10 min, then immersed in a C@CeO2 / Zn-MBO dispersion solution, transferred to a vacuum chamber, and vacuumized to ≤10 -2 Pa is maintained for 30-60 min, the vacuum is slowly released, the blank is taken out, washed with deionized water for 3 times, then foil rolling, slitting, and reverse winding are carried out to obtain the high-strength and high-toughness battery aluminum foil.

[0027] Preferably, the cold rolling is annealed at a low temperature of 220-240 DEG C after the 5th pass of rolling to 0.4-0.45 mm, and the annealing is maintained for 10-15 h; the passes of the foil rolling are (0.25-0.30) mm, (0.12-0.15) mm, (0.050-0.060) mm, (0.020-0.025) mm, (0.012-0.014) mm, and 0.010 mm, respectively.

[0028] In the present application, after the cold rolling stage, the rough rolling is carried out to a predetermined thickness, and then long-time low-temperature annealing is carried out to promote the diffusion of vacancies to fill micro-cracks, so that the pinhole area density is reduced and the elongation is improved.

[0029] The present application also provides a high-strength and high-toughness battery aluminum foil, which comprises the following raw materials in parts by mass: 70-95 parts of aluminum ingot, 5-30 parts of recycled aluminum foil, 0.1-0.3 parts of nickel-coated graphene particles, 0.2-0.3 parts of Al-Ti-B-Ce grain refiner, and 5 parts of C@CeO2 / Zn-MBO.

[0030] In the present application, the battery aluminum foil has good strength and toughness and improved electrical conductivity by the ratio of the raw material formula, and recycling of resources is realized.

[0031] The above technical scheme of the present application at least has the following beneficial effects: 1、The application adds nickel-coated graphene particles as a solid lubricant to significantly improve the mechanical properties and toughness of aluminum alloy. Graphene enhances the tensile strength and fatigue resistance of aluminum foil, while the nickel coating improves the interfacial bonding between graphene and the aluminum matrix, promoting material densification. The high aspect ratio of graphene can enhance toughness by refining aluminum grains, while improving electrical conductivity and current conduction efficiency.

[0032] 2、The application uses Al-Ti-B-Ce grain refiner, in which TiB2 is used as the core component to refine aluminum alloy grains through heterogeneous nucleation. The tiny particles of TiB2 provide a large number of nucleation sites to improve grain refinement. The rare earth element Ce improves the melt flowability, prevents the agglomeration and sedimentation of second-phase particles, promotes uniform nucleation, and further improves the tensile strength and elongation of aluminum alloy.

[0033] 3、The application realizes the loading of zinc ions and 2-mercapto benzoxazole (MBO) through the surface active sites of CeO2 and the porous carbon-coated CeO2 hollow sphere structure, forming a C@CeO2 / Zn-MBO composite material. This material can trigger the release of zinc ions under different pH conditions, forming a passivation film to inhibit corrosion. At the same time, MBO enhances the corrosion inhibition effect through synergistic action with zinc ions, and the external carbon layer provides a continuous conductive path to improve the corrosion resistance and electrical conductivity of aluminum foil materials. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Scanning electron microscope image of the high-strength and high-toughness battery aluminum foil sample prepared in Example 1 of the application; Figure 2 Scanning electron microscope image of the high-strength and high-toughness battery aluminum foil sample prepared in Comparative Example 4 of the application. DETAILED DESCRIPTION

[0035] To make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme of the embodiments of the application will be described below in conjunction with the embodiments of the application. The described embodiments are part of the embodiments of the application, and all other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the application belong to the scope of protection of the application.

[0036] Example 1 After 20 parts of graphene powder are immersed in an acetone solution and ultrasonic treated at 40℃ for 30 min, the precipitate is filtered, added to distilled water at 60℃ and stirred for 40 min, then the precipitate is filtered, immersed in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonic treated for 30 min, the precipitate is filtered and repeatedly washed with distilled water for 5 times, dried, and the pretreated graphene powder is obtained; 2 parts of nickel nitrate hexahydrate, 0.6 parts of sodium borohydride, 8 parts of citric acid, and 90 parts of water are mixed and stirred for 20 min, sodium hydroxide is added to adjust the pH to 6.5, and a nickel-containing mixed solution is obtained; 15 parts of the pretreated graphene powder is added to 20 parts of the nickel-containing mixed solution, ultrasonic treated at a constant ultrasonic oscillation with a temperature of 40℃, a frequency of 25 kHz, and a power of 250 W for 3 h, the precipitate is filtered, vacuum dried for 18 h, and the nickel-coated graphene particles are obtained.

[0037] After the cylindrical battery is discharged to 0.1V, the battery, separator, cathode electrode, and anode electrode are disassembled, the electrodes are cleaned with dimethyl carbonate, the double-sided electrode is cut into small pieces, the cathode electrode is placed in a glycerol-triacetate solvent, the temperature is stabilized at 100℃, the solid-liquid ratio is 1:10, and after stirring for 50 min under ultrasonic treatment, the temperature is cooled to room temperature, the aluminum foil is manually separated, rinsed with ethanol, and centrifuged at 150℃ for 5 min, the upper polyvinylidene fluoride residue is separated, and then the recovered aluminum foil is dried.

[0038] Under an argon environment, 10 parts of aluminum titanium boron wire (item number: HC02-20250609) and 0.05 parts of stearic acid are placed in a ball mill, ball milled at a speed of 150 r / min for 50 min, 0.2 parts of cerium dioxide powder is added and ball milled for another 50 min, then placed in an extrusion mold, cold pressed at 500 MPa for 30 min, heated to 500℃ and kept for 50 min, extruded at an extrusion ratio of 30:1, and slowly cooled to obtain an Al-Ti-B-Ce grain refiner.

[0039] Porous carbon coated CeO2 hollow spheres (C@CeO2) were prepared by dissolving 10 parts of cerium nitrate hexahydrate and 5 parts of citric acid monohydrate in 1000 parts of deionized water, stirring at room temperature for 4 hours, and then standing under microwave conditions at 130 W and 150 DEG C for 2 minutes. After cooling, the product was filtered, washed, and dried, and then annealed at 600 DEG C for 1 hour under an argon atmosphere to obtain the porous carbon coated CeO2 hollow spheres. Then, 6 parts of the porous carbon coated CeO2 hollow spheres were added to 1000 parts of an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2 (containing 0.5 parts of 2-mercaptobenzoxazole and 9.5 parts of Zn(NO3)2), and stirred at a speed of 100 r / min for 24 hours. The product was centrifuged at a speed of 700 r / min for 8 minutes, and the supernatant was discarded. The precipitate was washed with deionized water 5 times, and then dried at 65 DEG C under vacuum for 18 hours to obtain C@CeO2 / Zn-MBO. Then, 5 parts of the C@CeO2 / Zn-MBO were added to 500 parts of an ethanol solution, and ultrasonically dispersed for 30 minutes to obtain a C@CeO2 / Zn-MBO dispersion.

[0040] Under an argon atmosphere, 80 parts of aluminum ingot and 20 parts of recycled aluminum foil were placed in a graphite crucible, melted at 750 DEG C under electromagnetic stirring, and then transferred to a holding furnace at 750 DEG C for 10 minutes. Three times of refining treatment were performed, each for 30 minutes, with an interval of 4 hours. After the refining treatment, the surface dross was removed, and 0.3 parts of nickel-coated graphene particles and 0.3 parts of Al-Ti-B-Ce grain refiner were added through an online aluminum melt treatment system. The melt was continuously stirred at a speed of 700 r / min for 20 minutes. The melt was degassed by introducing high-purity argon at a flow rate of 25 L / min while maintaining the temperature at 750 DEG C. The dross floating to the surface of the melt was removed every 1 hour. The dross was removed by a tubular filtration and plate filtration system with a filtration mesh size of 50 mesh and 60 mesh. The liquid aluminum alloy melt was cast-rolled into a cast-rolled blank with a thickness of 7.2 mm under the conditions of a melt temperature of 700 DEG C in the front box and a cast-rolling speed of 960 mm / min in the cast-rolling zone. The cast-rolled blank was rolled into a foil-rolled blank with a thickness of 0.3 mm through 6 passes under the conditions of a work roll hardness of 90-95 HSD, a roughness of 0.12 um, and a crown of 0.09 mm. Low-temperature annealing was performed at 240 DEG C for 15 hours after the 5th pass to a thickness of 0.45 mm. After ultrasonic cleaning in a mixture of acetone and ethanol (volume ratio of 1:1) for 10 minutes, the foil-rolled blank was immersed in the C@CeO2 / Zn-MBO dispersion, transferred to a vacuum chamber, and vacuumed to ≤10 -2 Pa for 60 minutes. The blank was removed by slowly releasing the vacuum, washed with deionized water 3 times, and then foil-rolled. The pass numbers of the foil-rolling were 0.30 mm, 0.15 mm, 0.060 mm, 0.025 mm, 0.014 mm, and 0.010 mm, respectively. The foil-rolled blank was slit, uncoiled, and then a high-strength and high-toughness battery aluminum foil was obtained.

[0041] Example 2 After 20 parts of graphene powder were immersed in an acetone solution and ultrasonically treated at 40℃ for 30 min, the precipitate was filtered, added to distilled water at 50℃ and stirred for 20 min, then the precipitate was filtered, immersed in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonically treated for 20 min, and the precipitate was filtered and repeatedly washed with distilled water for 3 times, and then dried to obtain pretreated graphene powder; 2 parts of nickel nitrate hexahydrate, 0.6 parts of sodium borohydride, 8 parts of citric acid, and 90 parts of water were mixed and stirred for 20 min, and sodium hydroxide was added to adjust the pH to 5.5 to obtain a nickel-containing mixed solution; 5 parts of pretreated graphene powder was added to 20 parts of the nickel-containing mixed solution, and ultrasonic treatment was carried out at a temperature of 40℃, a frequency of 25 kHz, and a power of 250 W for 1 h under constant ultrasonic oscillation, the precipitate was filtered, and vacuum drying was carried out for 12 h to obtain nickel-coated graphene particles.

[0042] After the cylindrical battery was discharged to 0.1 V, the battery, separator, cathode electrode and anode electrode were disassembled, the electrodes were cleaned with dimethyl carbonate, the double-sided electrode was cut into small pieces, the cathode electrode was placed in a glycerol-triacetate solvent, the temperature was stabilized at 100℃, the solid-liquid ratio was 1:10, and after stirring for 30 min under ultrasonic treatment, it was cooled to room temperature, the aluminum foil was manually separated, rinsed with ethanol, and centrifuged at 90℃ for 5 min, the upper polyvinylidene fluoride residue was separated, and then dried to obtain the recovered aluminum foil.

[0043] Under an argon environment, 8 parts of aluminum titanium boron wire (item number: HC02-20250609) and 0.04 parts of stearic acid were placed in a ball mill, ball milled at a speed of 150 r / min for 30 min, then 0.1 parts of cerium dioxide powder was added and ball milled for another 30 min, then placed in an extrusion die, cold pressed at 500 MPa for 20 min, then heated to 500℃ and kept for 30 min, extruded at an extrusion ratio of 30:1, and slowly cooled to obtain an Al-Ti-B-Ce grain refiner.

[0044] Porous carbon coated CeO2 hollow spheres (C@CeO2) were prepared by dissolving 10 parts of cerium nitrate hexahydrate and 5 parts of citric acid monohydrate in 1000 parts of deionized water, stirring at room temperature for 4 hours, and then standing for 2 minutes under microwave conditions at 95 W and 150°C. After cooling, the product was filtered, washed, and dried, and then annealed at 600°C for 1 hour under an argon atmosphere to obtain the porous carbon coated CeO2 hollow spheres. Then, 6 parts of the porous carbon coated CeO2 hollow spheres were added to 1000 parts of an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2 (containing 0.5 parts of 2-mercaptobenzoxazole and 9.5 parts of Zn(NO3)2), and stirred at a speed of 100 r / min for 16 hours. The product was centrifuged at a speed of 700 r / min for 8 minutes, and the supernatant was discarded. The precipitate was washed with deionized water 5 times, and then vacuum dried at 65°C for 12 hours to obtain C@CeO2 / Zn-MBO. Then, 5 parts of the C@CeO2 / Zn-MBO were added to 500 parts of an ethanol solution, and ultrasonically dispersed for 30 minutes to obtain a C@CeO2 / Zn-MBO dispersion.

[0045] Under an argon atmosphere, 70 parts of aluminum ingot and 30 parts of recycled aluminum foil were placed in a graphite crucible, melted at 720°C under electromagnetic stirring, and then transferred to a holding furnace at 750°C for 10 minutes. Three refining treatments were performed, each for 20 minutes, with an interval of 2.5 hours. After refining, the surface dross was removed, and 0.1 parts of nickel-coated graphene particles and 0.2 parts of Al-Ti-B-Ce grain refiner were added online through an aluminum melt online treatment system. The melt was continuously stirred at a speed of 700 r / min for 10 minutes. The melt was degassed by introducing high-purity argon at a flow rate of 25 L / min while maintaining the temperature at 750°C. The dross floating to the surface of the melt was removed every 1 hour. The dross was removed by a tubular filtration and plate filtration system with a filtration mesh size of 50 mesh and 60 mesh. The liquid aluminum alloy melt was cast-rolled into a cast-rolled blank with a thickness of 6.8 mm under the conditions of a melt temperature of 700°C in the front box and a cast-rolling speed of 960 mm / min in the cast-rolling zone. The cast-rolled blank was rolled to a foil-rolled blank with a thickness of 0.25 mm in 6 passes under the conditions of a work roll hardness of 90-95 HSD, a roughness of 0.12 um, and a crown of 0.09 mm. Low-temperature annealing was performed at 220°C for 10 hours after the 5th pass to 0.4 mm. After ultrasonic cleaning in a mixture of acetone and ethanol (volume ratio of 1:1) for 10 minutes, the foil-rolled blank was immersed in the C@CeO2 / Zn-MBO dispersion and transferred to a vacuum chamber. The chamber was evacuated to ≤10 -2 After maintaining the vacuum at ≤10 Pa for 30 minutes, the blank was removed by slowly releasing the vacuum. After rinsing with deionized water 3 times, the blank was foil-rolled in 6 passes with a thickness of 0.25 mm, 0.12 mm, 0.050 mm, 0.020 mm, 0.012 mm, and 0.010 mm, respectively. The foil-rolled blank was slit, uncoiled, and then a high-strength and high-toughness battery aluminum foil was obtained.

[0046] Example 3 After 20 parts of graphene powder were immersed in an acetone solution and ultrasonically treated at 40℃ for 30 min, the precipitate was filtered, added to distilled water at 55℃ and stirred for 30 min, then the precipitate was filtered, immersed in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonically treated for 25 min, and the precipitate was filtered and repeatedly washed with distilled water 4 times, and then dried to obtain pretreated graphene powder; 2 parts of nickel nitrate hexahydrate, 0.6 parts of sodium borohydride, 8 parts of citric acid, and 90 parts of water were mixed and stirred for 20 min, and sodium hydroxide was added to adjust the pH to 6.3 to obtain a nickel-containing mixed solution; 10 parts of pretreated graphene powder was added to 20 parts of the nickel-containing mixed solution, and ultrasonic treatment was performed at a temperature of 40℃, a frequency of 25 kHz, and a power of 250 W for 2 h under constant ultrasonic oscillation, the precipitate was filtered, and vacuum drying was performed for 16 h to obtain nickel-coated graphene particles.

[0047] After the cylindrical battery was discharged to 0.1V, the battery, separator, cathode electrode and anode electrode were disassembled, the electrodes were cleaned with dimethyl carbonate, the double-sided electrode was cut into small pieces, the cathode electrode was placed in a glycerol-triacetate solvent, the temperature was stabilized at 100℃, the solid-liquid ratio was 1:10, and after stirring for 40 min under ultrasonic treatment, it was cooled to room temperature, the aluminum foil was manually separated, rinsed with ethanol, and centrifuged at 100℃ for 5 min, the upper polyvinylidene fluoride residue was separated, and then dried to obtain the recovered aluminum foil.

[0048] Under an argon atmosphere, 9 parts of aluminum titanium boron wire (item number: HC02-20250609) and 0.046 parts of stearic acid were placed in a ball mill, ball milled at a speed of 150 r / min for 40 min, then 0.15 parts of cerium dioxide powder was added and ball milled for another 40 min, then placed in an extrusion die, cold pressed at 500 MPa for 25 min, then heated to 500℃ and kept for 40 min, extruded at an extrusion ratio of 30:1, and slowly cooled to obtain an Al-Ti-B-Ce grain refiner.

[0049] Porous carbon coated CeO2 hollow spheres (C@CeO2) were prepared by dissolving 10 parts of cerium nitrate hexahydrate and 5 parts of citric acid monohydrate in 1000 parts of deionized water, stirring at room temperature for 4 hours, and then standing under microwave conditions at 120 W and 150°C for 2 minutes. After cooling, the product was filtered, washed, and dried, and then annealed at 600°C for 1 hour under an argon atmosphere to obtain the porous carbon coated CeO2 hollow spheres. Then, 6 parts of the porous carbon coated CeO2 hollow spheres were added to 1000 parts of an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2 (containing 0.5 parts of 2-mercaptobenzoxazole and 9.5 parts of Zn(NO3)2), and stirred at a speed of 100 r / min for 20 hours. The product was centrifuged at a speed of 700 r / min for 5 minutes, and the supernatant was discarded. The precipitate was washed with deionized water 5 times and vacuum dried at 65°C for 16 hours to obtain C@CeO2 / Zn-MBO. Then, 5 parts of the C@CeO2 / Zn-MBO were added to 500 parts of an ethanol solution and ultrasonically dispersed for 30 minutes to obtain a C@CeO2 / Zn-MBO dispersion.

[0050] Under an argon atmosphere, 95 parts of aluminum ingot and 5 parts of recycled aluminum foil were placed in a graphite crucible, melted at 740°C under electromagnetic stirring, and then transferred to a holding furnace at 750°C for 10 minutes. Three refining treatments were performed, each for 25 minutes, with an interval of 3 hours. After refining, the surface dross was removed, and 0.15 parts of nickel-coated graphene particles and 0.25 parts of Al-Ti-B-Ce grain refiner were added online through an aluminum melt online treatment system. The melt was continuously stirred at a speed of 700 r / min for 15 minutes. The melt was degassed by introducing high-purity argon at a flow rate of 25 L / min while maintaining the temperature at 750°C. The dross floating to the surface of the melt was removed every hour. The dross was removed by a tubular filtration and plate filtration system with a filtration mesh size of 50 mesh and 60 mesh. The liquid aluminum alloy melt was cast and rolled into a cast and rolled blank with a thickness of 6.9 mm under the conditions of a melt temperature of 700°C in the front box and a cast and rolling speed of 960 mm / min. The cast and rolled blank was rolled to a foil rolling blank with a thickness of 0.26 mm in 6 passes under the conditions of a work roll hardness of 90-95 HSD, a roughness of 0.12 um, and a crown of 0.09 mm. Low-temperature annealing was performed at 230°C for 12 hours after the 5th pass to 0.42 mm. After ultrasonic cleaning in a mixture of acetone and ethanol (volume ratio of 1:1) for 10 minutes, the foil rolling blank was immersed in the C@CeO2 / Zn-MBO dispersion and transferred to a vacuum chamber. The chamber was evacuated to ≤10 -2 After maintaining the vacuum at ≤10 Pa for 60 minutes, the blank was removed by slowly releasing the vacuum. The blank was washed with deionized water 3 times, and then foil rolling was performed with a pass of 0.26 mm, 0.13 mm, 0.045 mm, 0.022 mm, 0.013 mm, and 0.010 mm, respectively. The foil rolling blank was slit, uncoiled, and a high-strength and high-toughness battery aluminum foil was obtained.

[0051] Example 4 After 20 parts of graphene powder were immersed in an acetone solution and ultrasonically treated at 40℃ for 30 min, the precipitate was filtered, added to distilled water at 55℃ and stirred for 25 min, then the precipitate was filtered, immersed in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonically treated for 25 min, and the precipitate was filtered and repeatedly washed with distilled water for 3 times, and then dried to obtain pretreated graphene powder; 2 parts of nickel nitrate hexahydrate, 0.6 parts of sodium borohydride, 8 parts of citric acid, and 90 parts of water were mixed and stirred for 20 min, and sodium hydroxide was added to adjust the pH to 6.0 to obtain a nickel-containing mixed solution; 10 parts of pretreated graphene powder was added to 20 parts of the nickel-containing mixed solution, and ultrasonic treatment was carried out at a temperature of 40℃, a frequency of 25 kHz, and a power of 250 W for 1.5 h under constant ultrasonic oscillation, the precipitate was filtered, and vacuum drying was carried out for 14 h to obtain nickel-coated graphene particles.

[0052] After the cylindrical battery was discharged to 0.1V, the battery, separator, cathode electrode and anode electrode were disassembled, the electrodes were cleaned with dimethyl carbonate, the double-sided electrode was cut into small pieces, the cathode electrode was placed in a glycerol-triacetate solvent, the temperature was stabilized at 100℃, the solid-liquid ratio was 1:10, and after stirring for 45 min under ultrasonic treatment, it was cooled to room temperature, the aluminum foil was manually separated, rinsed with ethanol, and centrifuged at 110℃ for 5 min, the upper polyvinylidene fluoride residue was separated, and then dried to obtain the recovered aluminum foil.

[0053] Under an argon atmosphere, 8.5 parts of aluminum titanium boron wire (item number: HC02-20250609) and 0.04 parts of stearic acid were placed in a ball mill, ball-milled at a speed of 150 r / min for 35 min, then 0.15 parts of cerium dioxide powder was added and ball-milled for another 35 min, then placed in an extrusion die, cold-pressed at 500 MPa for 25 min, then heated to 500℃ and kept for 45 min, extruded at an extrusion ratio of 30:1, and slowly cooled to obtain an Al-Ti-B-Ce grain refiner.

[0054] Porous carbon coated CeO2 hollow spheres (C@CeO2) were prepared by dissolving 10 parts of cerium nitrate hexahydrate and 5 parts of citric acid monohydrate in 1000 parts of deionized water, stirring at room temperature for 4 hours, and then standing under microwave conditions at 130 W and 150°C for 2 minutes. After cooling, the product was filtered, washed, and dried, and then annealed at 600°C for 1 hour under an argon atmosphere to obtain the porous carbon coated CeO2 hollow spheres. Then, 6 parts of the porous carbon coated CeO2 hollow spheres were added to 1000 parts of an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2 (containing 0.5 parts of 2-mercaptobenzoxazole and 9.5 parts of Zn(NO3)2), and stirred at a speed of 100 r / min for 22 hours. The product was centrifuged at a speed of 700 r / min for 8 minutes, and the supernatant was discarded. The precipitate was washed with deionized water 5 times and dried at 65°C under vacuum for 18 hours to obtain C@CeO2 / Zn-MBO. Then, 5 parts of the C@CeO2 / Zn-MBO were added to 500 parts of an ethanol solution and ultrasonically dispersed for 30 minutes to obtain a C@CeO2 / Zn-MBO dispersion.

[0055] Under an argon atmosphere, 80 parts of aluminum ingot and 20 parts of recycled aluminum foil were placed in a graphite crucible, melted at 740°C under electromagnetic stirring, and then transferred to a holding furnace at 750°C for 10 minutes. Three refining treatments were performed, each for 25 minutes, with an interval of 3 hours. After refining, the surface dross was removed, and 0.25 parts of nickel-coated graphene particles and 0.25 parts of Al-Ti-B-Ce grain refiner were added online through an aluminum melt online treatment system. The melt was continuously stirred at a speed of 700 r / min for 15 minutes. The melt was degassed by introducing high-purity argon at a flow rate of 25 L / min while maintaining the temperature at 750°C. The dross floating to the surface of the melt was removed every hour. The dross was removed by a tubular filtration and plate filtration system with a filtration mesh size of 50 mesh and 60 mesh. The liquid aluminum alloy melt was cast-rolled into a cast-rolled blank with a thickness of 7.1 mm under the conditions of a melt temperature of 700°C in the front box and a cast-rolling speed of 960 mm / min in the cast-rolling zone. The cast-rolled blank was rolled to a foil-rolled blank with a thickness of 0.3 mm in 6 passes under the conditions of a work roll hardness of 90-95 HSD, a roughness of 0.12 um, and a crown of 0.09 mm. Low-temperature annealing was performed at 220°C for 15 hours after the 5th pass to 0.4 mm. After ultrasonic cleaning in a mixture of acetone and ethanol (volume ratio of 1:1) for 10 minutes, the foil-rolled blank was immersed in the C@CeO2 / Zn-MBO dispersion and transferred to a vacuum chamber. The chamber was evacuated to ≤10 -2 Pa for 60 minutes, and then the vacuum was slowly released to remove the blank. The blank was washed with deionized water 3 times, and then foil-rolled in 6 passes with a thickness of 0.30 mm, 0.15 mm, 0.060 mm, 0.025 mm, 0.014 mm, and 0.010 mm, respectively. The foil-rolled blank was slit, reversed, and then a high-strength and high-toughness battery aluminum foil was obtained.

[0056] Example 5 After 20 parts of graphene powder were immersed in an acetone solution and ultrasonically treated at 40℃ for 30 min, the precipitate was filtered, added to distilled water at 50℃ and stirred for 40 min, then the precipitate was filtered, immersed in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonically treated for 20 min, and the precipitate was filtered and repeatedly washed with distilled water for 5 times, and then dried to obtain pretreated graphene powder; 2 parts of nickel nitrate hexahydrate, 0.6 parts of sodium borohydride, 8 parts of citric acid, and 90 parts of water were mixed and stirred for 20 min, and sodium hydroxide was added to adjust the pH to 5.5 to obtain a nickel-containing mixed solution; 15 parts of pretreated graphene powder were added to 20 parts of the nickel-containing mixed solution, and ultrasonic treatment was performed at a temperature of 40℃, a frequency of 25 kHz, and a power of 250 W for 3 h under constant ultrasonic oscillation, the precipitate was filtered, and vacuum drying was performed for 12 h to obtain nickel-coated graphene particles.

[0057] After the cylindrical battery was discharged to 0.1V, the battery, separator, cathode electrode and anode electrode were disassembled, the electrodes were cleaned with dimethyl carbonate, the double-sided electrode was cut into small pieces, the cathode electrode was placed in a glycerol-triacetate solvent, the temperature was stabilized at 100℃, the solid-liquid ratio was 1:10, and after stirring for 50 min under ultrasonic treatment, it was cooled to room temperature, the aluminum foil was manually separated, rinsed with ethanol, and centrifuged at 90℃ for 5 min, the upper polyvinylidene fluoride residue was separated, and then dried to obtain the recovered aluminum foil.

[0058] Under an argon environment, 10 parts of aluminum titanium boron wire (item number: HC02-20250609) and 0.05 parts of stearic acid were placed in a ball mill, ball milled at a speed of 150 r / min for 50 min, then 0.1 parts of cerium dioxide powder was added and ball milled for another 50 min, then placed in an extrusion die, cold pressed at 500 MPa for 20 min, then heated to 500℃ and kept for 30 min, extruded at an extrusion ratio of 30:1, and slowly cooled to obtain an Al-Ti-B-Ce grain refiner.

[0059] Porous carbon coated CeO2 hollow spheres (C@CeO2) were prepared by dissolving 10 parts of cerium nitrate hexahydrate and 5 parts of citric acid monohydrate in 1000 parts of deionized water, stirring at room temperature for 4 h, and then standing for 2 min under microwave conditions at 110 W and 150℃. After cooling, the product was filtered, washed, and dried, and then annealed at 600℃ for 1 h under an argon atmosphere. 6 parts of the porous carbon coated CeO2 hollow spheres were added to 1000 parts of an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2 (containing 0.5 parts of 2-mercaptobenzoxazole and 9.5 parts of Zn(NO3)2), and stirred at a speed of 100 r / min for 18 h. The supernatant was discarded after centrifugation at a speed of 700 r / min for 7 min, and the precipitate was washed with deionized water 5 times and vacuum dried at 65℃ for 14 h to obtain C@CeO2 / Zn-MBO. 5 parts of the C@CeO2 / Zn-MBO were added to 500 parts of an ethanol solution and ultrasonically dispersed for 30 min to obtain a C@CeO2 / Zn-MBO dispersion.

[0060] Under an argon atmosphere, 90 parts of aluminum ingot and 10 parts of recycled aluminum foil were placed in a graphite crucible, and then melted by mechanical stirring with an iron stirring tool at 750℃. The molten aluminum was then transferred to a holding furnace at 750℃ and allowed to stand for 10 min. Three refining treatments were performed, each for 25 min, with an interval of 3.5 h. After refining, the surface dross was removed, and 0.3 parts of nickel-coated graphene particles and 0.2 parts of Al-Ti-B-Ce grain refiner were added online through an aluminum melt online treatment system. The molten aluminum was continuously stirred at a speed of 700 r / min for 20 min. The molten aluminum was degassed by introducing high-purity argon at a flow rate of 25 L / min while maintaining the temperature at 750℃. The dross floating to the surface of the molten aluminum was removed every 1 h. The dross was removed by a tubular filtration and plate filtration system with a filtration mesh size of 50 mesh and 60 mesh. The liquid aluminum alloy melt was cast and rolled into a cast and rolled blank with a thickness of 6.8 mm in a cast and rolled zone under the conditions of a front box melt temperature of 700℃ and a cast and rolled speed of 960 mm / min. The cast and rolled blank was rolled into a foil rolling blank with a thickness of 0.25 mm in 6 passes under the conditions of a work roll hardness of 90-95 HSD, a roughness of 0.12 um, and a crown of 0.09 mm. Low-temperature annealing was performed at 220℃ for 12 h after the 5th pass to a thickness of 0.45 mm. After ultrasonic cleaning in a mixture of acetone and ethanol (volume ratio of 1:1) for 10 min, the foil rolling blank was immersed in the C@CeO2 / Zn-MBO dispersion and transferred to a vacuum chamber. The chamber was evacuated to ≤10 -2Pa is maintained for 50 min, the blank is slowly taken out under a slow-release vacuum, and after being washed with deionized water for 3 times, the foil rolling blank is subjected to foil rolling, the rolling passes are 0.25 mm, 0.13 mm, 0.055 mm, 0.020 mm, 0.012 mm, 0.010 mm respectively, is cut, and is rolled back to obtain the high-toughness battery aluminum foil.

[0061] The present application also carries out comparative examples and related tests.

[0062] Comparative Example 1 Compared with Example 1, the only difference is that the nickel-coated graphene particles are not added, and the other preparation steps and components are completely consistent, and finally the high-toughness battery aluminum foil is prepared.

[0063] Comparative Example 2 Compared with Example 1, the only difference is that graphene is directly added instead of nickel-coated graphene particles, and the other preparation steps and components are completely consistent, and finally the high-toughness battery aluminum foil is prepared.

[0064] Comparative Example 3 Compared with Example 1, the only difference is that the Al-Ti-B-Ce grain refiner is directly added instead of Al-Ti-B-Ce grain refiner, and the other preparation steps and components are completely consistent, and finally the high-toughness battery aluminum foil is prepared.

[0065] Comparative Example 4 Compared with Example 1, the only difference is that C@CeO2 / Zn-MBO is not prepared, and the other preparation steps and components are completely consistent, that is, the cast rolling blank is rolled to a foil rolling blank with a thickness of 0.3 mm under the conditions that the work roll hardness is 90-95 HSD, the roughness is 0.12 um, and the crown is 0.09 mm, 6 passes, wherein, the low-temperature annealing is carried out at 240 DEG C to 0.45 mm in the 5th pass, and the holding time is 15 h; the foil rolling blank is subjected to foil rolling, the rolling passes are 0.30 mm, 0.15 mm, 0.060 mm, 0.025 mm, 0.014 mm, 0.010 mm respectively, is cut, and is rolled back to finally obtain the high-toughness battery aluminum foil.

[0066] Performance detection test The high-toughness battery aluminum foil samples prepared in Examples 1-5 and Comparative Examples 1-4 are evaluated according to the national standard GB / T33143-2022 aluminum and aluminum alloy foil for lithium ion battery, the average thickness deviation, the number of pinholes and the mechanical property test are carried out according to the test method of GB / T22638.11-2023 aluminum foil test method part 11: test method of mechanical property, and the direct current resistance test is carried out according to the test method of GB / T22638.6-2016 aluminum foil test method part 6: measurement of direct current resistance to evaluate its electrical conductivity, and the specific basic performance test results are shown in Table 1.

[0067] Table 1: Basic performance test result table

[0068] As can be seen from Table 1, the average thickness size deviation of the high-toughness battery aluminum foil test samples prepared by Examples 1-5 of the present application is ≤2.2%, the tensile strength is ≥200 MPa, and the number of pinholes is <1 per m 2 , which meets the standard of national standard GB / T33143-2022 aluminum and aluminum alloy foil for lithium ion battery.

[0069] According to the data analysis in Table 1, compared with Comparative Example 1, the addition of nickel-coated graphene particles in Example 1 improves the overall tensile strength and elongation, which plays a key role in enhancing the toughness of the battery aluminum foil; compared with Example 1, the addition of graphene alone in Comparative Example 2 results in poor dispersibility and interfacial adhesion, which significantly reduces the mechanical properties and electrical conductivity; compared with Example 1, the mechanical properties of Comparative Example 3 also decrease to a certain extent; compared with Example 1, the number of pinholes in Comparative Example 4 is significantly increased, and compared with Comparative Examples 1 and 2, the addition of nickel-coated graphene particles in Example 1 significantly reduces the number of surface pinholes.

[0070] The high-toughness battery aluminum foil test samples prepared in Examples 1-5 and Comparative Examples 1-4 were subjected to corrosion resistance testing. The aluminum foil test samples were placed in a hydrochloric acid solution with a volume concentration of 13%, and then the electrochemical corrosion process was simulated at a current density of 40 A / dm 2 for 10 min. The weight loss rate before and after the test was calculated, and the state of the aluminum foil test sample after the test was observed by scanning electron microscopy. The corrosion resistance test results are shown in Table 2.

[0071] Table 2: Corrosion resistance test result table

[0072] As can be seen from Table 2, the aluminum foil test samples prepared in Examples 1-5 of the present application still maintain a good state after the simulated electrochemical corrosion test, while the aluminum foil test samples prepared in Comparative Examples 1-4 all have corrosion phenomena, among which the corrosion phenomenon of Comparative Example 4 is the most serious due to the absence of C@CeO2 / Zn-MBO. Combined with the scanning electron microscopy images of the high-toughness battery aluminum foil test samples prepared in Example 1 and Comparative Example 4 after the simulated electrochemical corrosion test shown in Figure 1 and Figure 2 , it can be clearly seen that the high-toughness battery aluminum foil test sample prepared in Example 1 has no obvious pitting corrosion phenomenon after the simulated electrochemical corrosion test and still maintains a uniform and smooth surface, while the high-toughness battery aluminum foil test sample prepared in Comparative Example 4 has serious corrosion and peeling.

[0073] In summary, the application can achieve good tensile strength, ductility and corrosion resistance by using recycled waste aluminum foil to replace part of the aluminum ingot, and prepare high-toughness battery aluminum foil.

[0074] The above is the preferred embodiment of the application, and those skilled in the art can make several improvements and refinements without departing from the principles of the application, and these improvements and refinements should also be considered within the protection scope of the application.

Claims

1. A method for preparing high-strength and tough battery aluminum foil, characterized in that: The steps include: S1, adding the pretreated graphene powder to a nickel-containing mixed solution for ultrasonic treatment, filtering the precipitate, and vacuum drying to obtain nickel-coated graphene particles; S2, adding porous carbon-wrapped CeO2 hollow spheres to an aqueous solution containing 2-mercaptobenzoxazole and Zn(NO3)2, mixing and stirring, centrifuging, collecting the precipitate, washing, vacuum drying, adding the precipitate to an ethanol solution and ultrasonically dispersing the precipitate to obtain a C@CeO2 / Zn-MBO dispersion; S3. Under an inert gas environment, aluminum ingots and recycled aluminum foil are placed in a graphite crucible for melting, transferred to a heat preservation furnace for standing, refined, and nickel-coated graphene particles and Al-Ti-B-Ce grain refiner are added and stirred. The mixture is then degassed and deslagging, filtered, continuously cast and rolled, cold rolled, immersed in a C@CeO2 / Zn-MBO dispersion, and then foil rolled, slit, and rewound to obtain high-strength and tough battery aluminum foil.

2. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: The pretreated graphene powder is prepared by immersing the graphene powder in an acetone solution, ultrasonically treating the graphene powder at 40° C. for 30 minutes, filtering out a precipitate, adding the precipitate to distilled water at 50-60° C. and stirring the precipitate for 20-40 minutes, filtering out the precipitate, immersing the precipitate in a hydrofluoric acid solution with a mass concentration of 20%, ultrasonically treating the precipitate for 20-30 minutes, filtering out the precipitate, repeatedly rinsing the precipitate with distilled water for 3-5 times, and drying the precipitate. The nickel-containing mixed solution is prepared by mixing nickel nitric acid hexahydrate, sodium borohydride, citric acid, and water and stirring the mixture for 20 minutes, and adding sodium hydroxide to adjust the pH to 5.5-6.

5.

3. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: In step S1, the ultrasonic treatment is performed under constant ultrasonic oscillation at a temperature of 40° C., a frequency of 25 kHz, and a power of 250 W for a time of 1 to 3 hours, and the vacuum drying time is 12 to 18 hours.

4. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: The porous carbon-wrapped CeO2 hollow spheres are prepared by dissolving cerium nitrate hexahydrate and citric acid monohydrate in deionized water, stirring the mixture at room temperature for 4 hours, placing the mixture under microwave conditions of 95-130W and 150°C for 2 minutes, cooling the mixture, filtering, washing, and drying the mixture, and annealing the mixture at 600°C for 1 hour under an argon atmosphere.

5. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: In step S2, the mixing speed is 100 r / min and the time is 16-24 h, the centrifugal speed is 700 r / min and the time is 5-8 min, the deionized water is used for washing 5 times, the vacuum drying temperature is 65° C. and the time is 12-18 h, and the ultrasonic dispersion time is 30 min.

6. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: The Al-Ti-B-Ce grain refiner is prepared by placing aluminum titanium boron wire and stearic acid into a ball mill under an argon environment, ball milling at a speed of 150 r / min for 30 to 50 minutes, adding cerium dioxide powder and continuing ball milling for 30 to 50 minutes, placing the mixture into an extrusion die, cold pressing at 500 MPa for 20 to 30 minutes, heating the mixture to 500° C. and maintaining the temperature for 30 to 50 minutes, extruding the mixture at an extrusion ratio of 30:1, and slowly cooling the mixture.

7. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: The recycled aluminum foil is obtained by discharging a cylindrical battery to 0.1V, disassembling the battery, separator, cathode electrode and anode electrode, cleaning the electrodes with dimethyl carbonate, cutting the double-sided electrode into small pieces, placing the cathode electrode in a glycerol-triacetate solvent, stabilizing the temperature at 100°C, stirring for 30-50 minutes under ultrasonic treatment, cooling to room temperature, manually separating the aluminum foil, rinsing with ethanol, and centrifuging at 90-150°C for 5 minutes to separate the upper polyvinylidene fluoride residue, and then drying.

8. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: In the step S3, under an argon atmosphere, the aluminum ingot and the recovered aluminum foil are placed in a graphite crucible, melted at 720-750° C. under electromagnetic stirring, and then transferred to a 750° C. holding furnace for 10 minutes, and subjected to three refining treatments, each refining treatment time is 20-30 minutes, and the interval is 2.5-4 hours. After refining, the surface scum is scraped off, and nickel-coated graphene particles and Al-Ti-B-Ce grain refiner are added and stirred at a speed of 700 r / min for 10-20 minutes; continuous casting and rolling are carried out under the conditions of a front box melt temperature of 700° C. and a casting and rolling speed of 960 mm / min, and the liquid aluminum alloy melt is cast and rolled into a cast-rolled billet in the casting and rolling zone.

9. The method for preparing a high-strength and tough battery aluminum foil according to claim 1, characterized in that: In the step S3, cold rolling is carried out under the conditions that the working roll hardness is 90-95HSD, the roughness is 0.12μm, and the convexity is 0.09mm. After 6 passes of rolling to obtain a foil-rolled billet, the foil-rolled billet is immersed in an acetone / ethanol mixture for ultrasonic cleaning for 10 minutes, immersed in a C@CeO2 / Zn-MBO dispersion, transferred to a vacuum chamber, and evacuated to ≤10 -2 Pa is maintained for 30 to 60 minutes, and the vacuum is slowly released to take out the blank. After rinsing with deionized water three times, the foil is rolled, slit, and rewound to obtain high-strength and tough battery aluminum foil.

10. A high-strength and tough battery aluminum foil, characterized in that: The high-strength and tough battery aluminum foil is prepared by the preparation method of any one of claims 1 to 9, comprising the following raw materials in parts by mass: 70 to 95 parts of aluminum ingots, 5 to 30 parts of recycled aluminum foil, 0.1 to 0.3 parts of nickel-coated graphene particles, 0.2 to 0.3 parts of Al-Ti-B-Ce grain refiner, and 5 parts of C@CeO2 / Zn-MBO.

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