Method for preparing aluminum foil base material with nano honeycomb structure by wet method
The nano-honeycomb structure aluminum foil substrate was prepared by wet method, and the problems of insufficient bending resistance, conductivity and tensile resistance of commercial aluminum foils in batteries and supercapacitors were solved, and the conductivity and strength were significantly improved, and the application range was broadened.
Patent Information
- Application Number
- CN202510122522.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-26
- Publication Date
- 2025-05-13
AI Technical Summary
The existing commercial high-specific surface current collector aluminum foil has poor bending resistance, conductivity and tensile resistance in batteries, supercapacitors and other devices, limiting its application in high-performance batteries and high-power devices.
The method of preparing nano-honeycomb structure aluminum foil substrates is used to prepare wet methods, including high-energy ion beam bombardment, micro-etching, electrochemical etching, power-up multi-stage formation and etching treatment in a vacuum environment, forming a hierarchical porous structure with orderly nested large pores, mesopores and micropores.
It significantly improves the conductivity, tensile strength and bending resistance of aluminum foil, improves the conductivity by more than 11.1% and the tensile strength by more than 10%, and broadens its application range in high-performance batteries and electronic devices.
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Figure CN119980243A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of modification and preparation of aluminum foil substrates, and in particular to a method for preparing an aluminum foil substrate with a nano honeycomb structure by a wet process. Background Art
[0002] In the field of battery manufacturing, commercial aluminum foil is often used as a current collector material. Due to its advantages of light weight, low cost, and good conductivity, aluminum foil can effectively conduct the current generated by the positive electrode of the battery, thereby improving the overall performance of the battery. In common battery systems such as lithium-ion batteries, aluminum foil can stably carry active substances to ensure that the transmission path of electrons is unobstructed during the charging and discharging process of the battery, thereby maintaining the normal operation of the battery. Traditional commercial high-surface-rate current collector aluminum foil used in devices such as batteries and supercapacitors is usually made by immersing the metal foil in a specific corrosive solution. The corrosive solution reacts chemically with the metal foil to form micropores, nanopores or rough microstructures on the surface of the metal foil, thereby increasing the specific surface area.
[0003] However, the existing commercial high-surface-rate current collector aluminum foil also has some obvious defects in the production and application of devices such as batteries and supercapacitors. In terms of anti-bending performance, commercial high-surface-rate current collector aluminum foil may be subjected to various external forces, including vibration, extrusion, etc., during the battery assembly production or use process. The commercial high-surface-rate current collector aluminum foil has poor anti-bending performance and is prone to cracks or even breaks after repeated bending, which will destroy the current conduction path inside the battery, resulting in a decrease in battery performance, and in severe cases, the battery will fail; in terms of conductive performance, although the commercial high-surface-rate current collector aluminum foil has a certain conductivity, its conductivity is relatively low compared to metals such as silver and copper. In some application scenarios that require extremely high battery energy density and charge and discharge efficiency, the low conductivity of commercial high specific surface area current collector aluminum foil will increase the internal resistance of the battery, reduce the charge and discharge speed, and limit the application of the battery in high-power demand equipment; in terms of tensile resistance, the performance of commercial high specific surface area current collector aluminum foil is also unsatisfactory. During the battery production, assembly or use process and when subjected to external pulling force, the commercial high specific surface area current collector aluminum foil is easily stretched, deformed or even torn, which will not only affect the adhesion stability between the active material and the current collector, but may also cause serious problems such as internal short circuit, affecting the safety and service life of the battery.
[0004] These defects limit the application of existing commercial high-surface current collector aluminum foil in fields such as aerospace and high-performance electric vehicles that have extremely stringent requirements on battery performance and stability. Therefore, the existing technology still needs to be improved and developed. Summary of the invention
[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a method for wet-process preparation of a nano-honeycomb structure aluminum foil substrate, aiming to solve the problems of poor conductivity, bending resistance and tensile strength of existing commercial high specific surface area current collector aluminum foil.
[0006] The technical solution of the present invention is as follows:
[0007] A method for preparing a nano honeycomb structure aluminum foil substrate by a wet process, comprising the steps of:
[0008] In a vacuum environment, an inert gas is introduced, and the surface of the aluminum foil substrate is bombarded for 1-30 seconds using a high-energy ion beam generated by an anode layer ion source to remove impurities on the surface of the aluminum foil substrate;
[0009] In a vacuum environment, an etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to micro-etch the bombarded aluminum foil substrate for 1-20 seconds, wherein the gas flow rate is controlled to be 20-500 sccm, the current is 0.05-2A, and the voltage is 500V-1500V;
[0010] The aluminum foil substrate that has been micro-etched is placed in an electrolyte for electrochemical etching for 12-80 seconds, the temperature is 15-60°C, the frequency is 20-50Hz, and the processing voltage is 1-6V; then it is washed in deionized water at 15-60°C for 2-20S, and then it is subjected to strong acid or strong alkali corrosion treatment at 20-60°C for 4-20S, and finally it is washed in deionized water at 15-60°C for 2-20S to obtain an electrochemically etched aluminum foil substrate;
[0011] The electrochemically etched aluminum foil substrate is further subjected to a multi-stage electrochemical treatment: in the first stage, electrochemically formed in one or more mixed solutions of 0.2%-4% adipic acid, 0.5%-5% sodium chloride, 0.3%-6% oxalic acid, and 0.02%-8% hydrochloric acid, with a conductivity of 5-40 μs / cm, a pH of 4.0-7.0, a voltage of 0.1-2V, a temperature of 60-100°C, a treatment time of 40-100S, and then washed in deionized water at 20-60°C for 2-20S; in the second stage, electrochemically formed in a mixed solution of 0.1%-5% azelaic acid, 0.5%- Electrochemically formed in one or more mixed solutions of 5% sodium chloride, 0.3%-6% oxalic acid, and 0.02%-8% hydrochloric acid, with a conductivity of 10-50μs / cm, a pH of 4.0-7.0, a voltage of 0.8-2.5V, a temperature of 60-100℃, a treatment time of 40-100S, and then washed in deionized water at 20-60℃ for 2-20S; the third stage, electrochemically formed in one or more mixed solutions of 0.1%-5% azelaic acid, 0.3%-6% oxalic acid, and 0.02%-8% hydrochloric acid, with a conductivity of 10-50μs / cm. / cm, pH 4.0-7.0, voltage 2-4V, temperature 60-100℃, treatment time 40-100S, followed by 20-60℃ deionized water cleaning for 2-20S; the fourth stage, electrochemically formed in one or more mixed solutions of 0.1%-5% adipic acid, 0.5%-5% sodium chloride, 0.5%-6% oxalic acid, 0.05%-6% phosphoric acid, conductivity 10-50μs / cm, pH 4.0-7.0, voltage 3-5V, temperature 60-100℃, treatment time 40-100S , then wash in deionized water at 20-60℃ for 2-20S; the fifth stage, electrochemically formed in one or more mixed solutions of 0.1%-5% azelaic acid, 0.5%-5% sodium chloride, 0.5%-6% oxalic acid, and 0.05%-6% phosphoric acid, with a conductivity of 10-50μs / cm, a pH of 4.0-7.0, a voltage of 4-6V, a temperature of 60-100℃, and a treatment time of 40-100S, then wash in deionized water at 20-60℃ for 2-20S; finally enter the oven for treatment at 160-300℃ for 2-10 minutes;
[0012] In a vacuum environment, etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to etch the aluminum foil substrate that has undergone powered multi-stage chemical treatment for 2-10S, and the gas flow rate is controlled to be 50-100sccm, the current is 0.1A-1A, and the voltage is 200V-500V. Finally, a hierarchical porous structure composed of orderly nested combinations of macropores, mesopores and micropores is etched on the surface of the aluminum foil substrate to obtain a nano honeycomb aluminum foil substrate, wherein the diameter of the macropores is 100-500nm, the diameter of the mesopores is 2-6nm, and the diameter of the micropores is 0.3-2nm.
[0013] The method for preparing a nano honeycomb structure aluminum foil substrate by a wet process comprises the step of placing the aluminum foil substrate that has been subjected to micro-etching treatment in an electrolyte for electrochemical etching treatment, wherein the electrolyte is one or more of 0.02%-6% potassium chloride, 0.01%-5% sodium chloride, 0.03%-6% aluminum chloride and 0.02%-8% hydrochloric acid.
[0014] The method for preparing a nano honeycomb structure aluminum foil substrate by a wet method comprises the following steps: in the step of performing strong acid or strong alkali corrosion treatment at 20-60° C., the strong acid is one or both of 0.02%-5% phosphoric acid and 0.01%-4% nitric acid; and the strong alkali is 0.03%-5% sodium hydroxide.
[0015] The method for preparing a nano honeycomb structure aluminum foil substrate by a wet process, wherein the etching gas is one or more of hydrogen, fluorine, nitrogen trifluoride, chlorine and carbon tetrafluoride.
[0016] A nano honeycomb structure aluminum foil substrate is prepared by the wet method for preparing a nano honeycomb structure aluminum foil substrate according to the present invention.
[0017] Beneficial effects: Compared with the high specific surface area current collector aluminum foil (commercial high specific surface area current collector aluminum foil) of existing commercial capacitors and supercapacitors, the nano honeycomb aluminum foil substrate prepared by the wet method of the present invention has significantly improved performance in conductivity, tensile strength, bending resistance, specific volume and other aspects. The conductivity of commercial high specific surface area current collector aluminum foil is generally 3.85*10 7 S / m, and the conductivity of the nano honeycomb aluminum foil substrate prepared by the wet method of the present invention can be increased to 4.28*10 7 S / m, the improvement is as high as 11.1%, which makes it have great advantages in the fields of electronic devices, battery electrodes and other fields with strict requirements on conductive properties, and can effectively reduce resistance loss and improve energy transmission efficiency; the tensile strength of commercial high specific surface area current collector aluminum foil is 140-180MPa, while the tensile strength of the nano honeycomb aluminum foil prepared by the present invention is significantly enhanced, which can reach more than 200MPa, and the improvement is more than 10%; the commercial high specific surface area current collector aluminum foil will crack or even break due to material fatigue after repeated bending about 100 times, which limits its application in some scenes that require frequent bending, while the nano honeycomb aluminum foil prepared by the present invention has better bending resistance due to its unique surface graded porous structure. After testing, it can withstand more than 160 bendings under the same bending conditions, which greatly broadens its scope of use. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is an electron microscope image of the nano honeycomb aluminum foil substrate prepared by the wet treatment process in Example 1 at a molecular scale of 100 nm.
[0019] Figure 2 This is an electron microscope image of the nano honeycomb aluminum foil substrate prepared by the wet treatment process in Example 2 at a molecular scale of 40 nm.
[0020] Figure 3 This is an electron microscope image of the nano honeycomb aluminum foil substrate prepared by the wet treatment process in Example 3 at a molecular scale of 40 nm.
[0021] Figure 4 This is a plane electron microscope image of the high specific surface area current collector aluminum foil of existing commercial capacitors and supercapacitors.
[0022] Figure 5 This is a cross-sectional electron microscope image of the aluminum foil in-situ pinned growth solid-based carbon nanotube array material prepared in Example 4 at a scale of 20 μm. DETAILED DESCRIPTION
[0023] The present invention provides a method for preparing a nano honeycomb structure aluminum foil substrate by a wet process. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0024] Example 1
[0025] A method for preparing a nano honeycomb structure aluminum foil substrate by a wet process comprises the following steps:
[0026] Step 1: At a vacuum degree of 2*10 -3 In a vacuum environment of 1.5 Pa, an inert gas was introduced, and the surface of the aluminum foil substrate was bombarded for 15 seconds using a high-energy ion beam generated by an anode layer ion source to remove impurities on the surface of the aluminum foil substrate. The inert gas flow rate was controlled to be 200 sccm, the current was 1.5 A, and the voltage was 1500 V. The inert gas used was nitrogen.
[0027] Step 2: When the vacuum degree is 5*10 -2 In a vacuum environment of 1.5 Pa, an etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to perform micro-etching on the bombarded aluminum foil substrate for 10 seconds, wherein the gas flow rate is controlled to be 200 sccm, the current is 1 A, and the voltage is 1000 V, and the etching gas is hydrogen;
[0028] Step 3, the aluminum foil substrate after micro-etching is placed in a 3% by mass potassium chloride solution for electrochemical etching for 40 seconds, the temperature is 40°C, the frequency is 35Hz, and the processing voltage is 4V; then it is washed in 40°C deionized water for 10S and then subjected to strong acid corrosion treatment at 40°C for 15S, the strong acid is 3% by mass phosphoric acid, and finally it is washed in 40°C deionized water for 10S to obtain an electrochemically etched aluminum foil substrate;
[0029] Step 4, the electrochemically etched aluminum foil substrate is further subjected to multi-stage electrochemical treatment: the first stage is electrochemically formed in 2% adipic acid, with a conductivity of 20μs / cm, a pH of 6.0, a voltage of 1.5V, a temperature of 80°C, a treatment time of 60S, and then washed in deionized water at 40°C for 10S; the second stage is electrochemically formed in a mixed solution of 3% azelaic acid and 2% sodium chloride, with a conductivity of 30μs / cm, a pH of 5.0, a voltage of 1.5V, a temperature of 80°C, a treatment time of 80S, and then washed in deionized water at 40°C for 10S; the third stage is electrochemically formed in a 2% azelaic acid solution, with a conductivity of 30μs / cm, a pH of 5.0, a voltage of 1.5V, a temperature of 80°C, a treatment time of 80S, and then washed in deionized water at 40°C for 10S. s / cm, pH is 5.0, voltage is 3V, temperature is 80℃, treatment time is 80S, then clean in deionized water at 40℃ for 10S; fourth level, electrochemically formed in 3% adipic acid solution, conductivity is 30μs / cm, pH is 6.0, voltage is 4V, temperature is 80℃, treatment time is 80S, then clean in deionized water at 40℃ for 10S; fifth level, electrochemically formed in 3% sodium chloride solution, conductivity is 30μs / cm, pH is 5.0, voltage is 5V, temperature is 70℃, treatment time is 70S, then clean in deionized water at 40℃ for 10S; finally enter the oven for treatment at 200℃ for 5 minutes.
[0030] Step 5: When the vacuum degree is 5*10 -2 In a vacuum environment of 1.5 Pa, hydrogen etching gas is introduced, and the aluminum foil substrate subjected to the powered multi-stage chemical treatment is etched for 5S by a high-energy ion beam generated by a radio frequency ion source, and the gas flow rate is controlled to be 80sccm, the current is 0.5A, and the voltage is 300V. Finally, a hierarchical porous structure composed of an orderly nested combination of macropores, mesopores and micropores is etched on the surface of the aluminum foil substrate to obtain a nano honeycomb aluminum foil substrate, wherein the diameter of the macropores is 100-500nm, the diameter of the mesopores is 2-6nm, and the diameter of the micropores is 0.3-2nm.
[0031] Example 2
[0032] A method for preparing a nano honeycomb structure aluminum foil substrate by a wet process comprises the following steps:
[0033] Step 1: At a vacuum degree of 1*10 -4 In a vacuum environment of 1.5 Pa, an inert gas was introduced, and the surface of the aluminum foil substrate was bombarded for 2 seconds using a high-energy ion beam generated by an anode layer ion source to remove impurities on the surface of the aluminum foil substrate. The inert gas flow rate was controlled to be 20 sccm, the current was 0.5 A, and the voltage was 800 V. The inert gas used was argon.
[0034] Step 2: When the vacuum degree is 1*10 -4In a vacuum environment of 1.5 Pa, an etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to micro-etch the bombarded aluminum foil substrate for 2S, wherein the gas flow rate is controlled to be 20 sccm, the current is 0.05 A, and the voltage is 500 V, and the etching gas is fluorine gas;
[0035] Step 3, the aluminum foil substrate after micro-etching is placed in a sodium chloride electrolyte with a mass percentage of 3% for electrochemical etching for 12 seconds, the temperature is 15°C, the frequency is 20Hz, and the processing voltage is 1V; then it is washed in 15°C deionized water for 2S and then subjected to strong alkali corrosion treatment for 4S at 20°C, the strong alkali is 2% by mass sodium hydroxide, and finally it is washed in 15°C deionized water for 2S to obtain an electrochemically etched aluminum foil substrate;
[0036] Step 4, the electrochemically etched aluminum foil substrate is further subjected to multi-stage electrochemical treatment: the first stage, electrochemically formed in a mixed solution of 0.2% adipic acid and 0.5% sodium chloride, with a conductivity of 5μs / cm, a pH of 4.0, a voltage of 0.1V, a temperature of 60°C, a treatment time of 40S, and then washed in deionized water at 20°C for 2S; the second stage, electrochemically formed in a mixed solution of 0.1% azelaic acid and 0.3% oxalic acid, with a conductivity of 10μs / cm, a pH of 4.0, a voltage of 0.8V, a temperature of 60°C, a treatment time of 40S, and then washed in deionized water at 20°C for 2S; the third stage, electrochemically formed in a mixed solution of 1% azelaic acid and 1% hydrochloric acid Electrochemical formation, conductivity is 10μs / cm, pH is 4.0, voltage is 2V, temperature is 60℃, treatment time is 40S, then rinse in deionized water at 20℃ for 2S; fourth stage, electrochemical formation in 1% phosphoric acid solution, conductivity is 10μs / cm, pH is 5.0, voltage is 3V, temperature is 60℃, treatment time is 40S, then rinse in deionized water at 20℃ for 2S; fifth stage, electrochemical formation in 0.5% sodium chloride solution, conductivity is 10μs / cm, pH is 5.0, voltage is 4V, temperature is 60℃, treatment time is 40S, then rinse in deionized water at 20℃ for 2S; finally enter the oven for treatment at 160℃ for 2 minutes;
[0037] Step 5: When the vacuum degree is 1*10 -4 In a vacuum environment of 1.5 Pa, fluorine gas is introduced as etching gas, and the aluminum foil substrate subjected to the powered multi-stage chemical treatment is etched for 2S by a high-energy ion beam generated by a radio frequency ion source. The gas flow rate is controlled to be 50 sccm, the current is 0.1A, and the voltage is 200V. Finally, a hierarchical porous structure composed of an orderly nested combination of macropores, mesopores and micropores is etched on the surface of the aluminum foil substrate to obtain a nano honeycomb aluminum foil substrate, wherein the diameter of the macropores is 100-500nm, the diameter of the mesopores is 2-6nm, and the diameter of the micropores is 0.3-2nm.
[0038] Example 3
[0039] Step 1: At a vacuum degree of 4*10 2 In a vacuum environment of 1.5 Pa, an inert gas is introduced, and the surface of the aluminum foil substrate is bombarded for 30 seconds using a high-energy ion beam generated by an anode layer ion source to remove impurities on the surface of the aluminum foil substrate. The inert gas flow rate is controlled to be 500 sccm, the current is 3A, and the voltage is 3000V. The inert gas used is one or more of nitrogen and argon.
[0040] Step 2: In a vacuum environment with a vacuum degree of 5*10Pa, an etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to micro-etch the bombarded aluminum foil substrate for 20S, wherein the gas flow rate is controlled to be 500sccm, the current is 2A, and the voltage is 1500V, and the etching gas is chlorine;
[0041] Step 3, the aluminum foil substrate that has been micro-etched is placed in a mixed electrolyte consisting of 5% sodium chloride and 4% hydrochloric acid for electrochemical etching for 80 seconds, the temperature is 60°C, the frequency is 50Hz, and the processing voltage is 6V; then it is washed in 60°C deionized water for 20S and then treated with a strong acid at 60°C for 20S, the strong acid is 4% nitric acid by mass, and finally it is washed in 60°C deionized water for 20S to obtain an electrochemically etched aluminum foil substrate.
[0042] Step 4, the electrochemically etched aluminum foil substrate is further subjected to multi-stage electrochemical treatment: the first stage is electrochemically formed in a mixed solution of 4% adipic acid and 8% hydrochloric acid, with a conductivity of 40μs / cm, a pH of 6.0, a voltage of 2V, a temperature of 100°C, a treatment time of 100S, and then washed in deionized water at 60°C for 20S; the second stage is electrochemically formed in a 5% sodium chloride solution, with a conductivity of 50μs / cm, a pH of 7.0, a voltage of 2.5V, a temperature of 100°C, a treatment time of 100S, and then washed in deionized water at 60°C for 20S; the third stage is electrochemically formed in a 5% azelaic acid solution, with a conductivity of 50μs / cm, a pH of 6.0, a voltage of The first stage is 4V, the temperature is 100℃, the processing time is 100S, and then it is washed in deionized water at 60℃ for 20S; the fourth stage is electrochemically formed in a mixed solution of 5% adipic acid and 6% phosphoric acid, the conductivity is 50μs / cm, the pH is 5.0, the voltage is 5V, the temperature is 100℃, the processing time is 100S, and then it is washed in deionized water at 60℃ for 20S; the fifth stage is electrochemically formed in a mixed solution of 5% sodium chloride, 6% oxalic acid and 3% phosphoric acid, the conductivity is 50μs / cm, the pH is 6.0, the voltage is 6V, the temperature is 100℃, the processing time is 100S, and then it is washed in deionized water at 60℃ for 20S; finally, it enters the oven and is treated at 300℃ for 10 minutes;
[0043] Step 5. In a vacuum environment with a vacuum degree of 5*10Pa, chlorine is introduced as an etching gas, and the aluminum foil substrate that has undergone the powered multi-stage chemical treatment is etched for 10S using a high-energy ion beam generated by a radio frequency ion source. The gas flow rate is controlled to be 100sccm, the current is 1A, and the voltage is 500V. Finally, a hierarchical porous structure composed of an orderly nested combination of macropores, mesopores, and micropores is etched on the surface of the aluminum foil substrate to obtain a nano honeycomb aluminum foil substrate, wherein the diameter of the macropores is 100-500nm, the diameter of the mesopores is 2-6nm, and the diameter of the micropores is 0.3-2nm.
[0044] The nano honeycomb aluminum foil substrates prepared in Examples 1 to 3 were observed by electron microscope. The results are as follows: Figure 1-Figure 3 As shown, Figure 1 This is an electron microscope image of the nano honeycomb aluminum foil substrate prepared by the wet treatment process in Example 1 at a molecular scale of 100 nm. Figure 2 This is an electron microscope image of the nano honeycomb aluminum foil substrate prepared by the wet treatment process in Example 2 at a molecular scale of 40 nm. Figure 3 This is an electron microscope image of the nano honeycomb aluminum foil substrate prepared by the wet treatment process in Example 3 at a molecular scale of 40nm. Figure 1-Figure 3 It can be seen that the surfaces of the nano honeycomb aluminum foil substrates prepared by the wet method in Examples 1-3 of the present invention all present a hierarchical porous structure composed of an orderly nested combination of macropores, mesopores and micropores, the diameter of the macropores is 100-500nm, the diameter of the mesopores is 2-6nm, and the diameter of the micropores is 0.3-2nm, indicating that the method of the present invention has produced an aluminum foil with a nano honeycomb structure.
[0045] Figure 4 This is a plane electron microscope image of the high specific surface area current collector aluminum foil of existing commercial capacitors and supercapacitors. Figure 4 It can be seen that the surface of the commercial current collector aluminum foil presents a relatively complex microscopic morphology, with numerous irregular holes and protrusions, but the sizes and shapes of these holes vary, and the distribution is relatively random, without obvious regularity and order. The pore structure of the commercial capacitor current collector foil is randomly distributed, lacking the ordered macropore-mesopore-micropore ordered nested composite structure (such as the nano honeycomb aluminum foil prepared in Examples 1-3) Figure 1-3As shown in the figure, the ordered hierarchical porous structure of nano honeycomb aluminum foil can better store and transport ions and optimize the electrochemical performance of the electrode; although the commercial current collector aluminum foil has a certain specific surface area, the nano honeycomb aluminum foil can provide a larger and more effective specific surface area through a carefully designed hierarchical porous structure, and has more active sites to interact with the electrode active materials, thereby showing better performance in the electrochemical reaction. The commercial current collector foil has a disadvantage in this regard; at the same time, the special structure of the nano honeycomb aluminum foil also gives it better mechanical properties and structural stability.
[0046] The conductivity, bending resistance and tensile strength of the nano honeycomb aluminum foil substrate prepared in Examples 1-4 and the commercial high specific surface area current collector aluminum foil were tested. The results are shown in Table 1:
[0047] Table 1 Performance test results
[0048]
[0049] From the data in Table 1, it can be seen that the nano honeycomb aluminum foil substrate prepared by the wet method of the present invention has significantly improved performance in terms of conductivity, tensile strength, bending resistance, specific volume, etc. The conductivity of commercial high specific surface area current collector aluminum foil is generally 3.85*10 7 S / m, and the conductivity of the nano honeycomb aluminum foil substrate prepared by the wet method of the present invention can be increased to 4.28*10 7 S / m, the improvement is as high as 11.1%, which makes it have great advantages in the fields of electronic devices, battery electrodes and other fields with strict requirements on conductive properties, and can effectively reduce resistance loss and improve energy transmission efficiency; the tensile strength of commercial high specific surface area current collector aluminum foil is 140-180MPa, while the tensile strength of the nano honeycomb aluminum foil prepared by the present invention is significantly enhanced, which can reach more than 200MPa, and the improvement is more than 10%; the commercial high specific surface area current collector aluminum foil will crack or even break due to material fatigue after repeated bending about 100 times, which limits its application in some scenes that require frequent bending, while the nano honeycomb aluminum foil prepared by the present invention has better bending resistance due to its unique surface graded porous structure. After testing, it can withstand more than 160 bendings under the same bending conditions, which greatly broadens its scope of use.
[0050] Furthermore, the macroporous, mesoporous, and microporous embedded nano honeycomb aluminum foil substrate prepared by the method of the present invention also provides abundant nucleation sites and a good mechanical anchoring foundation for the growth of carbon nanotubes, so that the carbon nanotubes can be tightly and firmly attached thereto, thereby realizing the in-situ pinning growth of the solid-base carbon nanotube array on the aluminum foil, effectively solving the problem of easy detachment of the carbon nanotubes. The following is an explanation through specific embodiments:
[0051] Example 4
[0052] A method for in-situ pinning of aluminum foil to grow a solid-base carbon nanotube array comprises the following steps:
[0053] Step 1: The preparation of the nano honeycomb aluminum foil substrate is the same as that in Example 1;
[0054] Step 2: Depositing an iron-cobalt-nickel catalyst on a nano-honeycomb structure aluminum foil by a sol-gel method, wherein the mass ratio of Fe, Co, and Ni in the iron-cobalt-nickel catalyst is 5:5:1. The catalysts in this ratio work synergistically, and can efficiently catalyze the decomposition of the carbon source in the subsequent reaction process, promote the nucleation and growth of carbon nanotubes, and ensure that the grown carbon nanotubes have suitable key performance indicators such as tube diameter, wall thickness, and crystallinity.
[0055] Step 3: Place the nano honeycomb structure aluminum foil deposited with an iron-cobalt-nickel catalyst layer into the CVD furnace, turn on the vacuum pump to evacuate the CVD furnace, and introduce argon to remove the air in the furnace to ensure the purity of the reaction environment and prevent impurity gases from interfering with the growth of carbon nanotubes; then start heating the CVD furnace, and turn off the argon when the heating rate reaches 420°C at a rate of 10°C / min. This heating rate can not only ensure a smooth transition of the reaction system, but also gradually activate the catalyst within a suitable temperature range, thus preparing for subsequent catalytic reactions; the vacuum pump is turned on, and hydrogen and argon are injected for 10 minutes, and the vacuum pump is turned off. At this stage, hydrogen plays a role in reducing the oxide on the catalyst surface and further activating the catalyst.
[0056] Step 4: Continue to raise the temperature of the CVD furnace to 450°C and keep it warm for 10 minutes. This insulation process is a key stage in the growth of carbon nanotubes. In this temperature range, the catalyst activity reaches its peak and can continuously catalyze the decomposition of the subsequently injected carbon source acetylene; then turn on the vacuum pump to evacuate the vacuum, and after the vacuum is evacuated, start injecting acetylene and introduce carbon dioxide and hydrogen to normal pressure. Carbon dioxide, as a mild oxidant, can adjust the growth rate and structural defects of carbon nanotubes, and work together with hydrogen and acetylene to accurately control the growth process of carbon nanotubes; then introduce argon, carbon dioxide, and acetylene, and start exhausting after 10 minutes to maintain normal pressure;
[0057] Step 5: After the heat preservation is completed, argon gas is introduced to cool down. Through this series of precise temperature, gas type and time control, after the reaction is completed, a firmly pinned carbon nanotube array is grown in situ on the surface of the nano-honeycomb structure aluminum foil.
[0058] Comparative Example 1
[0059] A method for in-situ growth of a carbon nanotube array on aluminum foil comprises the following steps:
[0060] Step 1: providing a commercial aluminum foil substrate without modifying the commercial aluminum foil substrate;
[0061] Steps 2-5 are the same as in Example 4.
[0062] The aluminum foil in-situ pinning growth solid-based carbon nanotube array prepared in Example 4 was observed by electron microscope. The results are as follows: Figure 5 As shown, from Figure 5 It can be seen that carbon nanotubes grow vertically on the upper and lower surfaces of the aluminum foil. The carbon nanotubes are pinned in situ and grow on the surface of the aluminum foil, forming a relatively regular array morphology.
[0063] Ultrasonic vibration tests were performed on the aluminum foil in-situ pinned growth solid-base carbon nanotube array material prepared in Example 4 and the aluminum foil in-situ grown carbon nanotube array material prepared in Comparative Example 1. Specifically, the material samples prepared in Example 4 and Comparative Example 1 were respectively placed in an ultrasonic cleaning machine, and vibrated for 1-5 hours under specific frequency (such as 20-50kHz) and power (such as 100-500W). After taking out, the adhesion of the carbon nanotubes on the surface of the aluminum foil was observed by scanning electron microscopy. The results showed that only a small amount of carbon nanotubes fell off from the sample in Example 7, and the overall array structure was not affected, while a large amount of carbon nanotubes fell off from the sample in Comparative Example 1. This shows that the carbon nanotube array in Example 4 is pinned to the surface of the aluminum foil, and its pinning firmness to the aluminum foil surface is better, while the carbon nanotube array in Comparative Example 1 has poor bonding firmness to the aluminum foil surface.
[0064] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.
Claims
1. A method for preparing a nano honeycomb structure aluminum foil substrate by a wet process, characterized in that: Includes steps: In a vacuum environment, an inert gas is introduced, and the surface of the aluminum foil substrate is bombarded for 1-30 seconds using a high-energy ion beam generated by an anode layer ion source to remove impurities on the surface of the aluminum foil substrate; In a vacuum environment, an etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to micro-etch the bombarded aluminum foil substrate for 1-20 seconds, wherein the gas flow rate is controlled to be 20-500 sccm, the current is 0.05-2A, and the voltage is 500V-1500V; The aluminum foil substrate that has been micro-etched is placed in an electrolyte for electrochemical etching for 12-80 seconds, the temperature is 15-60°C, the frequency is 20-50Hz, and the processing voltage is 1-6V; then it is washed in deionized water at 15-60°C for 2-20S, and then it is subjected to strong acid or strong alkali corrosion treatment at 20-60°C for 4-20S, and finally it is washed in deionized water at 15-60°C for 2-20S to obtain an electrochemically etched aluminum foil substrate; The electrochemically etched aluminum foil substrate is further subjected to a multi-stage electrochemical treatment: in the first stage, electrochemically formed in one or more mixed solutions of 0.2%-4% adipic acid, 0.5%-5% sodium chloride, 0.3%-6% oxalic acid, and 0.02%-8% hydrochloric acid, with a conductivity of 5-40 μs / cm, a pH of 4.0-7.0, a voltage of 0.1-2V, a temperature of 60-100°C, a treatment time of 40-100S, and then washed in deionized water at 20-60°C for 2-20S; in the second stage, electrochemically formed in a mixed solution of 0.1%-5% azelaic acid, 0.5%- Electrochemically formed in one or more mixed solutions of 5% sodium chloride, 0.3%-6% oxalic acid, and 0.02%-8% hydrochloric acid, with a conductivity of 10-50μs / cm, a pH of 4.0-7.0, a voltage of 0.8-2.5V, a temperature of 60-100℃, a treatment time of 40-100S, and then washed in deionized water at 20-60℃ for 2-20S; the third stage, electrochemically formed in one or more mixed solutions of 0.1%-5% azelaic acid, 0.3%-6% oxalic acid, and 0.02%-8% hydrochloric acid, with a conductivity of 10-50μs / cm. / cm, pH 4.0-7.0, voltage 2-4V, temperature 60-100℃, treatment time 40-100S, followed by 20-60℃ deionized water cleaning for 2-20S; the fourth stage, electrochemically formed in one or more mixed solutions of 0.1%-5% adipic acid, 0.5%-5% sodium chloride, 0.5%-6% oxalic acid, 0.05%-6% phosphoric acid, conductivity 10-50μs / cm, pH 4.0-7.0, voltage 3-5V, temperature 60-100℃, treatment time 40-100S , then wash in deionized water at 20-60℃ for 2-20S; the fifth stage, electrochemically formed in one or more mixed solutions of 0.1%-5% azelaic acid, 0.5%-5% sodium chloride, 0.5%-6% oxalic acid, and 0.05%-6% phosphoric acid, with a conductivity of 10-50μs / cm, a pH of 4.0-7.0, a voltage of 4-6V, a temperature of 60-100℃, and a treatment time of 40-100S, then wash in deionized water at 20-60℃ for 2-20S; finally enter the oven for treatment at 160-300℃ for 2-10 minutes; In a vacuum environment, etching gas is introduced, and a high-energy ion beam generated by a radio frequency ion source is used to etch the aluminum foil substrate that has undergone powered multi-stage chemical treatment for 2-10S, and the gas flow rate is controlled to be 50-100sccm, the current is 0.1A-1A, and the voltage is 200V-500V. Finally, a hierarchical porous structure composed of orderly nested combinations of macropores, mesopores and micropores is etched on the surface of the aluminum foil substrate to obtain a nano honeycomb aluminum foil substrate, wherein the diameter of the macropores is 100-500nm, the diameter of the mesopores is 2-6nm, and the diameter of the micropores is 0.3-2nm.
2. The method for preparing a nano honeycomb structure aluminum foil substrate by a wet method according to claim 1, characterized in that: In the step of placing the micro-etched aluminum foil substrate in an electrolyte for electrochemical etching, the electrolyte is one or more of 0.02%-6% potassium chloride, 0.01%-5% sodium chloride, 0.03%-6% aluminum chloride and 0.02%-8% hydrochloric acid.
3. The method for preparing a nano honeycomb structure aluminum foil substrate by a wet method according to claim 1, characterized in that: In the step of performing strong acid or strong alkali corrosion treatment at 20-60° C., the strong acid is one or two of 0.02%-5% phosphoric acid and 0.01%-4% nitric acid; the strong alkali is 0.03%-5% sodium hydroxide.
4. The method for preparing a nano honeycomb structure aluminum foil substrate by wet method according to claim 1, characterized in that: The etching gas is one or more of hydrogen, fluorine, nitrogen trifluoride, chlorine and carbon tetrafluoride.
5. A nano honeycomb structure aluminum foil substrate, characterized in that: The nano honeycomb structure aluminum foil substrate is prepared by the wet method for preparing the nano honeycomb structure aluminum foil substrate according to any one of claims 1 to 4.