Au/Cu2O composite material, super-assembly preparation method and application
阅读说明：本技术 一种Au/Cu/Cu2O复合材料、超组装制备方法及应用 (Au/Cu2O composite material, super-assembly preparation method and application ) 是由 孔彪 李东玮 何彦君 曾洁 王猛 于 2021-08-17 设计创作，主要内容包括：本发明属于锂-空气电池电极催化材料制备技术领域,提供了一种Au/Cu/Cu-(2)O复合材料、超组装制备方法及应用,首先制备得到金铜铝合金,然后在强碱溶液中进行脱合金反应,再在空气中进一步氧化,使铜部分氧化,即得Au/Cu/Cu-(2)O复合材料,制备工艺简单、不需要添加表面活性剂、适于大规模生产,制备得到的Au/Cu/Cu-(2)O复合材料因为具有双通道结构的纳米材料,其结构单元纳米颗粒之间的空隙为锂电池的反应提供了充足的反应空间,所以电池充放电过程中能够很好地缓解电极的体积效应,有助于倍率和循环性能的提升。Au/Cu/Cu-(2)O复合材料作为锂-空气电池的正极催化材料可以改善单一材料的电化学性能,提高锂-空气电池的倍率和循环性能,降低贵金属用量,节约成本。(The invention belongs to the technical field of preparation of electrode catalytic materials of lithium-air batteries, and provides Au/Cu 2 The O composite material, the super-assembly preparation method and the application thereof are characterized in that firstly, the gold-copper-aluminum alloy is prepared, then the dealloying reaction is carried out in the strong alkaline solution, and then the copper is further oxidized in the air to partially oxidize the copper, thus obtaining the Au/Cu 2 The O composite material has simple preparation process, does not need to add a surfactant, is suitable for large-scale production, and is prepared into Au/Cu 2 The O composite material has a double-channel structure nano material, and the gaps among the nano particles of the structural unit of the O composite material provide sufficient reaction space for the reaction of the lithium battery, so that the battery can be charged and dischargedThe volume effect of the electrode can be well relieved, and the multiplying power and the cycle performance are improved. Au/Cu 2 The O composite material used as the anode catalytic material of the lithium-air battery can improve the electrochemical performance of a single material, improve the multiplying power and the cycle performance of the lithium-air battery, reduce the consumption of noble metals and save the cost.)
1. Au/Cu2The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
step S1, smelting metal aluminum, metal gold and metal copper according to a certain mass ratio in an argon atmosphere by adopting a high-frequency induction furnace to obtain a gold-copper-aluminum alloy ingot;
step S2, heating the gold-copper-aluminum alloy cast ingot to a molten state, and blowing out a gold-copper-aluminum alloy strip on a single-roll chilling device;
step S3, grinding the gold copper aluminum alloy strip to obtain gold copper aluminum alloy powder;
step S4, placing the gold copper aluminum alloy powder in a strong alkaline solution, and reacting for a preset time at a preset fixed temperature to obtain a dealuminized alloy material;
step S5, carrying out oxidation reaction on the dealuminized alloy material in air at a preset temperature for a preset time to obtain Au/Cu2And (3) an O composite material.
2. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
in step S1, the purities of the metal aluminum, the metal gold and the metal copper are all 99.9%;
the atomic percentage of Al in the gold copper aluminum alloy ingot is 70-90%; the total atomic percentage of Au and Cu in the gold-copper-aluminum alloy ingot is 10-30%; the atomic percent of Au in the total atomic percent of Au and Cu is more than 0 and less than 100 percent.
3. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
wherein, the atomic percentage of Al in the gold copper aluminum alloy ingot is 80%; the total atomic percentage of Au and Cu in the gold-copper-aluminum alloy ingot is 20%; the atomic percent of Au in the total atomic percent of Au and Cu is more than 0 and less than 100 percent.
4. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
wherein, the thickness of the gold copper aluminum alloy strip is 20 to 60 mu m, and the width is 2 to 4 mm.
5. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
and putting the gold copper aluminum alloy powder obtained in the step S3 into ethanol and ultrapure water for ultrasonic cleaning to obtain cleaned gold copper aluminum alloy powder for use in the step S4.
6. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
in step S4, the reaction is carried out under magnetic stirring, wherein the rotation speed of the magnetic stirring is 1000-2000 rpm;
the strong alkali solution is a sodium hydroxide solution or a potassium hydroxide solution; the concentration of the strong alkali solution is 0.1-4M.
7. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
wherein the dealuminized alloy material obtained in the step S4 is repeatedly washed with water until the pH of the supernatant becomes 7, so as to obtain a washed dealuminized alloy material, which is used in the step S5.
8. Au/Cu according to claim 12The super-assembly preparation method of the O composite material is characterized by comprising the following steps:
in step S4, the preset temperature is 25-60 ℃; the preset time is 10-24 h;
in step S5, the preset temperature is 25-60 ℃; the preset time is 24-48 h.
9. Au/Cu2An O composite characterized by:
the Au/Cu2The O composite material is granular, and the grain diameter is 80 nm-700 nm; the particle size is a three-dimensional bicontinuous ligament or hole structure, the size of the hole channel of the hole is 10nm or 30nm,
wherein, the Au/Cu2O-composite material made of Au/Cu as claimed in any one of claims 1 to 82The O composite material is prepared by a super-assembly preparation method.
10. Au/Cu2The application of the O composite material in the lithium battery is characterized in that the material is Au/Cu2The O composite material is used as a positive electrode catalytic material of the lithium-air battery,
wherein, the Au/Cu2O-composite material made of Au/Cu as claimed in any one of claims 1 to 82The O composite material is prepared by a super-assembly preparation method.
Technical Field
The invention belongs to the technical field of preparation of electrode catalytic materials of lithium-air batteries, and particularly relates to Au/Cu2O composite material, super-assembly preparation method and application.
Background
The lithium-air battery is a secondary battery which takes metal lithium as a negative electrode and air (or oxygen) as a positive electrode, and the theoretical energy density of the lithium-air battery is greatly superior to that of the traditional primary zinc-manganese battery and secondary nickel-hydrogen and lithium-ion batteries. In addition, the lithium-air battery also has the advantages of environmental friendliness, low price and the like. However, in the absence of the catalyst, the charge-discharge reaction kinetics process is relatively slow, and the difference between the charge voltage and the discharge voltage is about 1.5V, so that the normal operation of the battery reaction is seriously influenced by such a large overpotential. Meanwhile, the electrolyte is easy to decompose due to large overpotential, and potential safety hazards exist. Research shows that the catalyst loaded on the anode can obviously reduce the voltage difference between charging and discharging, and improve the coulombic efficiency and the cycle performance of the battery. The common catalysts at present comprise carbon materials, metal oxides and noble metal catalysts. Among them, some functional groups present on carbon materials are easily decomposed during charge and discharge cycles, and thus are not preferable as a positive electrode catalyst for a lithium-air battery. The noble metal catalyst has high conductivity, high electrocatalytic performance and good stability, can effectively reduce polarization, and is an ideal catalyst for the anode of the lithium-air battery. However, noble metal catalysts are costly and limit their commercial use.
At present, many reports are made on lithium-air battery positive electrode catalysts based on the compounding of noble metals and oxides, and most of the oxides in the compounds are transition metal oxides of Co, Ni and Mn, so that the cost is high. The resource storage of Cu on the earth is rich, and Cu2O has been widely used in various fields as a catalyst, but Cu has not been reported2The application of O in lithium-air batteries. Therefore, there is a need to develop a noble metal and Cu2O-hybrid lithium-air batteryThe positive electrode catalyst of (1).
Disclosure of Invention
The present invention has been made to solve the above problems, and an object of the present invention is to provide Au/Cu2O composite material, super-assembly preparation method and application.
The invention provides Au/Cu2A method for the super-assembly preparation of an O-composite material, characterized in that it comprises the following steps: step S1, smelting metal aluminum, metal gold and metal copper according to a certain mass ratio in an argon atmosphere by adopting a high-frequency induction furnace to obtain a gold-copper-aluminum alloy ingot; step S2, heating the gold-copper-aluminum alloy cast ingot to a molten state, and blowing out a gold-copper-aluminum alloy strip on a single-roll chilling device by using argon; step S3, grinding the gold copper aluminum alloy strip to obtain gold copper aluminum alloy powder; step S4, placing the gold copper aluminum alloy powder in a strong alkaline solution, and reacting for a preset time at a preset temperature to obtain a dealuminized alloy material; step S5, carrying out oxidation reaction on the dealuminized alloy material in air at a preset temperature for a preset time to obtain Au/Cu2And (3) an O composite material.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: in step S1, the purities of the metal aluminum, the metal gold and the metal copper are all 99.9%; the atomic percentage of Al in the gold-copper-aluminum alloy ingot is 70-90 percent; the total atomic percentage of Au and Cu in the gold-copper-aluminum alloy ingot is 10 to 30 percent; the atomic percent of Au in the total atomic percent of Au and Cu is more than 0 and less than 100 percent.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: in step S1, the atomic percent of Al in the gold-copper-aluminum alloy ingot is 80%; the total atomic percentage of Au and Cu in the gold-copper-aluminum alloy ingot is 20 percent; the atomic percent of Au in the total atomic percent of Au and Cu is more than 0 and less than 100 percent.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: wherein the thickness of the gold copper aluminum alloy strip is 20 mum to 60 mu m and 2mm to 4mm in width.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: and putting the gold copper aluminum alloy powder obtained in the step S3 into ethanol and ultrapure water for ultrasonic cleaning to obtain cleaned gold copper aluminum alloy powder for use in the step S4.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: wherein, in step S4, the reaction is carried out under magnetic stirring, and the rotating speed of the magnetic stirring is 1000 rpm-2000 rpm; the strong alkali solution is sodium hydroxide solution or potassium hydroxide solution; the concentration of the strong alkali solution is 0.1M-4M.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: the dealuminized alloy material obtained in step S4 was repeatedly washed with water until the pH of the supernatant was 7, and the washed dealuminized alloy material was obtained for use in step S5.
In the invention, Au/Cu is provided2The super-assembly preparation method of the O composite material can also have the following characteristics: wherein in the step S4, the preset temperature is 25-60 ℃; the preset time is 10-24 h; in step S5, the preset temperature is 25-60 ℃; the preset time is 24-48 h.
The invention also provides Au/Cu2An O-composite having the following characteristics: Au/Cu2The O composite material is granular, and the grain diameter is 80 nm-700 nm; the particle size is a three-dimensional bicontinuous ligament or hole structure, and the size of a hole channel of the hole is 10nm or 30 nm; Au/Cu2The O composite material is made of Au/Cu2The O composite material is prepared by a super-assembly preparation method.
The invention also provides Au/Cu2The application of the O composite material in the lithium battery has the following characteristics: Au/Cu2O composite material as anode catalyst material of lithium-air battery, Au/Cu2The O composite material is made of Au/Cu2The O composite material is prepared by a super-assembly preparation method.
Action and Effect of the invention
Au/Cu related to the invention2The O composite material, the super-assembly preparation method and the application thereof are characterized in that firstly, metal aluminum, metal gold and metal copper are prepared into gold-copper-aluminum alloy according to a certain mass ratio, then dealuminization reaction is carried out in strong alkaline solution to obtain dealuminization alloy, further oxidation is carried out in the air to partially oxidize the copper, and Au/Cu is obtained2The method has simple preparation process, does not need to add a surfactant and is suitable for large-scale production.
Au/Cu prepared by the invention2O composite material because of Au/Cu2The O composite material is a nano material with a dual-channel structure, and gaps among nano particles of the structural unit of the O composite material provide sufficient reaction space for the reaction of the lithium battery, so that the volume effect of an electrode can be well relieved in the charging and discharging processes of the battery, and the multiplying power and the cycle performance are improved. And each structural unit consists of three-dimensional bicontinuous nanopores and has a high specific surface area, so that a rich three-phase reaction interface can be provided for the oxygen reduction reaction of the lithium battery.
Au/Cu prepared by the invention2The O composite material can be used as a positive electrode catalytic material of a lithium-air battery, and the advantages of the alloy and the oxide can be combined, so that the electrochemical performance of a single material can be improved, the multiplying power and the cycle performance of the lithium-air battery can be improved, the consumption of noble metals can be reduced, and the cost can be saved.
Drawings
FIG. 1 is a diagram of AuCuAl alloy precursors prepared in example 1 of the present invention and Au/Cu prepared in example 1 of the present invention2The X-ray diffraction pattern (XRD) of the O-composite;
FIG. 2 shows Au/Cu obtained in example 1 of the present invention2X-ray photoelectron spectroscopy (XPS) of O-composites;
FIG. 3 is Au/Cu obtained in example 1 of the present invention2Scanning Electron Microscope (SEM) of the O composite;
FIG. 4 shows Au/Cu obtained in example 1 of the present invention2Transmission Electron Microscopy (TEM) of the O composite;
FIG. 5 shows Au/Cu obtained in example 1 of the present invention2A charge-discharge curve diagram of a lithium-air battery with the O composite material as a positive electrode;
FIG. 6 is a CuAl alloy precursor prepared in a comparative example of the present invention and Cu/Cu alloy prepared in a comparative example of the present invention2The X-ray diffraction pattern (XRD) of the O-composite;
FIG. 7 is a Cu/Cu alloy prepared in comparative example of the present invention2Transmission Electron Microscopy (TEM) of the O composite;
FIG. 8 shows Au/Cu obtained in comparative example of the present invention2A charge-discharge curve diagram of a lithium-air battery with the O composite material as a positive electrode;
FIG. 9 shows Au/Cu obtained in example 2 of the present invention2Scanning Electron Microscope (SEM) of the O composite; and
FIG. 10 shows Au/Cu obtained in example 3 of the present invention2Scanning Electron Micrograph (SEM) of the O-composite.
Detailed Description
In order to make the technical means, creation features, achievement objects and effects of the present invention easy to understand, the following embodiments are provided to illustrate an Au/Cu of the present invention with reference to the accompanying drawings2The O composite material, the super-assembly preparation method and the application are specifically described.
The starting materials used in the present invention are commercially available or commonly used in the art, unless otherwise specified, and the methods in the following examples are conventional in the art, unless otherwise specified.
The invention provides Au/Cu2The super-assembly preparation method of the O composite material specifically comprises the following steps:
and step S1, smelting metal aluminum with the purity of 99.9%, metal gold with the purity of 99.9% and metal copper with the purity of 99.9% in an argon atmosphere by adopting a high-frequency induction furnace according to a certain mass ratio to obtain the gold-copper-aluminum alloy ingot.
In the step, the atomic percent of Al in the gold copper aluminum alloy ingot is 70-90 percent; the total atomic percentage of Au and Cu in the gold-copper-aluminum alloy ingot is 10 to 30 percent; the atomic percentage of Au in the total atomic percentages of Au and Cu is more than 0 and less than 100%. In the present invention, the atomic ratios of metallic aluminum, metallic gold and metallic copper in the examples are 80:5:15, 80:15:5 and 80:10: 10. Preferably, the atomic ratio of Au, Cu and Al in the gold-copper-aluminum alloy ingot is 5:15: 80.
And step S2, heating the gold-copper-aluminum alloy cast ingot to a molten state, and blowing out a gold-copper-aluminum alloy strip with the thickness of 20-60 mu m and the width of 2-4 mm on a single roll chilling device by using argon.
In this step, the rotating speed of the single-roller chilling device is 1000-1500 revolutions/min. In the present invention, the rotating speed of the single-roll chilling device in the embodiment is only 1200 r/min, but the same technical effect can be achieved when the rotating speed of the single-roll chilling device is 1000 r/min to 1500 r/min.
Step S3, the gold copper aluminum alloy strip is ground to obtain gold copper aluminum alloy powder, and the obtained gold copper aluminum alloy powder is placed in ethanol and ultrapure water for ultrasonic cleaning to obtain cleaned gold copper aluminum alloy powder.
And step S4, placing the cleaned gold-copper-aluminum alloy powder in a strong alkaline solution, reacting for a preset time under magnetic stirring at a preset temperature to obtain a dealuminized alloy material, and repeatedly washing the obtained dealuminized alloy material with water until the pH value of the supernatant is 7 to obtain the cleaned dealuminized alloy material.
In the step, the strong alkali solution is sodium hydroxide solution or potassium hydroxide solution, and the concentration of the strong alkali solution is 0.1-4M. In the present invention, the sodium hydroxide solution having a concentration of 2M is used in the examples, but the same technical effects can be achieved by a strong alkali solution having a concentration of 0.1M to 4M, and preferably, the sodium hydroxide solution has a concentration of 2M.
In the step, the preset temperature is 25-60 ℃, and the preset time is 10-24 h. In the present invention, the predetermined temperature is 25 ℃ and the predetermined time is 24 hours in the examples. Preferably, the predetermined temperature is 25 ℃ and the predetermined time is 24 h.
In this step, the rotation speed of the magnetic stirring is 1000rpm to 2000 rpm. In the present invention, the rotation speed of magnetic stirring is only 1500rpm in the examples, but the same technical effects can be achieved by the rotation speed of magnetic stirring being 1000rpm to 2000 rpm.
Step S5, the cleaned dealuminized alloy material is subjected to oxidation reaction in air at a preset temperature for a preset time to obtain Au/Cu2And (3) an O composite material.
In the step, the preset temperature is 25-60 ℃, and the certain time is 24-48 hours. In the present invention, the predetermined temperature is 30 ℃ and the predetermined time is 48 hours in the examples. Preferably, the predetermined temperature is 30 ℃ and the predetermined time is 48 hours.
< example 1>
The invention provides Au/Cu2The super-assembly preparation method of the O composite material specifically comprises the following steps:
step S1, putting metal aluminum with the purity of 99.9%, metal gold with the purity of 99.9% and metal copper with the purity of 99.9% into a quartz tube according to the atomic ratio of 80:5:15, and smelting by adopting a high-frequency induction furnace under the protection of argon to obtain a gold-copper-aluminum alloy ingot with uniform components;
step S2, placing the obtained gold-copper-aluminum alloy cast ingot with uniform components in a quartz tube, heating to a molten state, and blowing out a gold-copper-aluminum alloy strip with the thickness of 20-60 mu m and the width of 2-4 mm by using argon on a single-roll chilling device with the rotating speed of 1200 r/min;
step S3, placing the gold copper aluminum alloy strip in a mortar for grinding to obtain gold copper aluminum alloy powder, weighing 0.1g of the gold copper aluminum alloy powder, placing the gold copper aluminum alloy powder in ethanol and ultrapure water for ultrasonic cleaning twice respectively, and obtaining cleaned gold copper aluminum alloy powder;
step S4, placing the cleaned gold-copper-aluminum alloy powder in 50mLNaOH (2M), magnetically stirring for 24h at the temperature of 25 ℃ and the rotation speed of 1500rpm to obtain a dealuminized alloy material, and repeatedly washing the dealuminized alloy material with water until the pH value of the supernatant is 7 to obtain the cleaned dealuminized alloy material;
step S5, oxidizing the dealuminized alloy material in air at 30 ℃ for 48h to obtain Au/Cu2And (3) an O composite material.
FIG. 1 shows AuCuAl alloy precursors in example 1 and Au/Cu obtained in example 12X-ray diffraction Pattern (XRD) of O-composite.
As shown in figure 1, AuCuAl alloy precursor (i.e. gold-copper-aluminum alloy strip) contains AuAl and CuAl alloy phases, and is subjected to corrosion by strong alkaline solution and secondary oxidation treatment to obtain AuCu3And Cu2Complex phase of O, AuCu according to relative intensity of diffraction peak in the figure3Is the major of the two phases.
FIG. 2 is the Au/Cu prepared in example 12X-ray photoelectron spectroscopy (XPS) of O-composites. FIG. 2(a) shows Au/Cu2The spectrum of Au 4f of the O composite material, FIG. 2(b) is Au/Cu2The spectrum of Cu 2p of the O composite, FIG. 2(c) is Au/Cu2The spectrum of Cu LMM of O composite, FIG. 2(d) is Au/Cu2Spectrum of O1s for O composite.
As shown in FIG. 2(a), the peak of Au 4f7/2 has an electron binding energy of 84.0eV, and is attributed to gold in a metallic state. As shown in FIG. 2(b), FIG. 2(c), FIG. 2(d), the electron binding energy of the Cu 2p3/2 peak is at 932.3eV, but the appearance of this peak cannot be directly proved to be Cu +, since Cu and Cu2The Cu 2p3/2 binding energies of O are very similar. The peaks at 941.0 and 943.5 eV belong to Cu2The peak position of electron binding energy of O, Cu LMM is 569.8eV, which is also similar to Cu2The electronic state of O is completely satisfied. Thus, it is understood that the metal layer is formed by Au/Cu2The super-assembly preparation method of the O composite material obtains Au/Cu2And (3) an O composite material.
FIG. 3 is Au/Cu obtained in example 12Scanning Electron Micrograph (SEM) of the O-composite.
As shown in FIG. 3, Au/Cu2The O composite material is granular, the grain diameter is 80nm to 700nm, the granules are in a bicontinuous interactive ligament or hole structure, and the size of a hole is 10nm or 30 nm.
FIG. 4 is Au/Cu obtained in example 12Transmission Electron Micrograph (TEM) of the O-composite.
As shown in fig. 4, clearlyThe structure showing open bicontinuous pore/ligament interaction is consistent with the results of the SEM photograph of FIG. 3, further confirming that Au/Cu2A nanoporous structure of an O-composite.
Au/Cu prepared in this example2Mixing an O composite material, activated carbon and PVDF according to a mass ratio of 5:3:2, adding a proper amount of NMP to form slurry, placing the slurry in a ball mill, carrying out ball milling for 4h at a rotating speed of 300r/min to obtain uniformly mixed slurry, uniformly coating the uniformly mixed slurry on carbon paper, drying in a vacuum drying box at 80 ℃ for 10h, cutting into a wafer with the diameter of 12mm, weighing to obtain a positive electrode, taking metal lithium as a negative electrode, taking a PP celgard2300 glass fiber membrane as a diaphragm and taking an electrolyte as 1MLiTFSI/TEGDME, assembling a battery in a glove box filled with argon, loading into a completely sealed test box filled with oxygen, standing for about 4h, and carrying out charge-discharge test.
FIG. 5 is Au/Cu obtained in example 12Charge-discharge curve of lithium-air battery with O composite material as positive electrode.
As shown in FIG. 5a, the cut-off capacity of the lithium-air battery is 600mAh/g, the current density is 100mA/g, and the lithium-air battery can keep stable circulation in 440 charging and discharging processes; as shown in FIG. 5b, the cut-off capacity is 1000mAh/g, the current density is 100mA/g, and the lithium-air battery can keep stable circulation in the process of 120 times of charging and discharging, the discharging termination potential is kept at about 2.5V, the charging termination voltage is kept at about 4.5V, and the lithium-air battery shows lower polarization and better circulation stability.
< comparative example >
Step S1, putting metal aluminum with the purity of 99.9 percent and metal copper with the purity of 99.9 percent into a quartz tube according to the atomic ratio of 80:20, and smelting by adopting a high-frequency induction furnace under the protection of argon to obtain copper-aluminum alloy cast ingots with uniform components;
s2, placing the obtained gold copper aluminum alloy ingot with uniform components in a quartz tube, heating to a molten state, and blowing out a copper aluminum alloy strip by using argon on a single-roll chilling device with the rotating speed of 1200 r/min;
step S3, placing the copper-aluminum alloy strip in a mortar for grinding to obtain copper-aluminum alloy powder, weighing 0.1g of the copper-aluminum alloy powder, placing the copper-aluminum alloy powder in ethanol and ultrapure water, and ultrasonically cleaning the copper-aluminum alloy powder twice respectively;
step S4, placing the cleaned copper-aluminum alloy powder in 50mL of NaOH (2M), magnetically stirring for 24h at 25 ℃ and 1500rpm to obtain a dealuminized alloy material, and repeatedly washing the dealuminized alloy material with water until the pH value of the supernatant is 7 to obtain the cleaned dealuminized alloy material;
step S5, oxidizing the dealuminized alloy material in air at 30 ℃ for 48h to obtain Cu/Cu2And (3) an O composite material.
FIG. 6 is a CuAl alloy precursor prepared in a comparative example and Cu/Cu alloy prepared in a comparative example2X-ray diffraction Pattern (XRD) of O-composite.
As shown in FIG. 6, the CuAl alloy precursor (i.e., the Cu-Al alloy strip) contains Al and Al2The alloy phase of Cu is corroded by strong alkaline solution and subjected to secondary oxidation treatment to obtain Cu and Cu2The complex phase of O, Cu is the main phase of the two phases according to the relative intensity of diffraction peaks in the figure.
FIG. 7 is Cu/Cu obtained in comparative example2Transmission Electron Micrograph (TEM) of the O-composite.
As shown in FIG. 7, the Cu/Cu2The O-composite material exhibits a bicontinuous pore/ligament interaction structure with pore sizes of 15 nm.
Cu/Cu prepared by the comparative example2Mixing an O composite material, activated carbon and PVDF according to a mass ratio of 5:3:2, adding a proper amount of NMP to form slurry, placing the slurry in a ball mill, carrying out ball milling for 4h at a rotating speed of 300r/min to obtain uniformly mixed slurry, uniformly coating the uniformly mixed slurry on carbon paper, drying in a vacuum drying box at 80 ℃ for 10h, cutting into a wafer with the diameter of 12mm, weighing, using metal lithium as a cathode, a PP celgard2300 glass fiber membrane as a diaphragm and 1M LiTFSI/TEGDME as electrolyte, assembling a battery in a glove box filled with argon, loading into a completely sealed test box filled with oxygen, standing for about 4h, and carrying out charging and discharging tests.
FIG. 8 is a drawing of a comparative exampleTo obtain Cu/Cu2Charge-discharge curve of lithium-air battery with O composite material as positive electrode.
As shown in FIG. 8, the lithium-air battery had a cut-off capacity of 600mAh/g, a current density of 100mA/g, and the cycle was 19 cycles, and only 8 cycles were performed at a cut-off capacity of 1000 mAh/g.
< example 2>
The invention provides Au/Cu2The super-assembly preparation method of the O composite material specifically comprises the following steps:
step S1, putting metal aluminum with the purity of 99.9%, metal gold with the purity of 99.9% and metal copper with the purity of 99.9% into a quartz tube according to the atomic ratio of 80:15:5, and smelting by adopting a high-frequency induction furnace under the protection of argon to obtain a gold-copper-aluminum alloy ingot with uniform components;
step S2, placing the obtained gold-copper-aluminum alloy cast ingot with uniform components in a quartz tube, heating to a molten state, and blowing out a gold-copper-aluminum alloy strip with the thickness of 20-60 mu m and the width of 2-4 mm by using argon on a single-roll chilling device with the rotating speed of 1200 r/min;
step S3, placing the gold copper aluminum alloy strip in a mortar for grinding to obtain gold copper aluminum alloy powder, weighing 0.1g of the gold copper aluminum alloy powder, placing the gold copper aluminum alloy powder in ethanol and ultrapure water for ultrasonic cleaning twice respectively, and obtaining cleaned gold copper aluminum alloy powder;
step S4, placing the cleaned gold-copper-aluminum alloy powder in 50mLNaOH (2M), magnetically stirring for 24h at the temperature of 25 ℃ and the rotation speed of 1500rpm to obtain a dealuminized alloy material, and repeatedly washing the dealuminized alloy material with water until the pH value of the supernatant is 7 to obtain the cleaned dealuminized alloy material;
step S5, oxidizing the dealuminized alloy material in air at 30 ℃ for 48h to obtain Au/Cu2And (3) an O composite material.
FIG. 9 is Au/Cu obtained in example 22Scanning Electron Micrograph (SEM) of the O-composite. FIG. 9(a) shows Au/Cu2Scanning Electron Micrograph (SEM) of the surface of O composite, and FIG. 9(b) is Au/Cu2Scanning Electron Micrograph (SEM) of the O-composite cross section.
As shown in FIGS. 9(a) and 9(b), Au/Cu2The O-composite was porous but, unlike the bicontinuous porous structure of example 1, the surface was divided into small pieces by some dense stripe-like structures, each piece of area exhibiting a bicontinuous alternating ligament/pore structure with a pore size of about 30 nm.
< example 3>
The invention provides Au/Cu2The super-assembly preparation method of the O composite material specifically comprises the following steps:
step S1, putting metal aluminum with the purity of 99.9%, metal gold with the purity of 99.9% and metal copper with the purity of 99.9% into a quartz tube according to the atomic ratio of 80:10:10, and smelting by adopting a high-frequency induction furnace under the protection of argon to obtain a gold-copper-aluminum alloy ingot with uniform components;
step S2, placing the obtained gold-copper-aluminum alloy cast ingot with uniform components in a quartz tube, heating to a molten state, and blowing out a gold-copper-aluminum alloy strip with the thickness of 20-60 mu m and the width of 2-4 mm by using argon on a single-roll chilling device with the rotating speed of 1200 r/min;
step S3, placing the gold copper aluminum alloy strip in a mortar for grinding to obtain gold copper aluminum alloy powder, weighing 0.1g of the gold copper aluminum alloy powder, placing the gold copper aluminum alloy powder in ethanol and ultrapure water for ultrasonic cleaning twice respectively, and obtaining cleaned gold copper aluminum alloy powder;
step S4, placing the cleaned gold-copper-aluminum alloy powder in 50mLNaOH (2M), magnetically stirring for 24h at the temperature of 25 ℃ and the rotation speed of 1500rpm to obtain a dealuminized alloy material, and repeatedly washing the dealuminized alloy material with water until the pH value of the supernatant is 7 to obtain the cleaned dealuminized alloy material;
step S5, oxidizing the dealuminized alloy material in air at 30 ℃ for 48h to obtain Au/Cu2And (3) an O composite material.
FIG. 10 shows Au/Cu obtained in example 32Scanning Electron Micrograph (SEM) of the O-composite. FIG. 10(a) shows Au/Cu2Scanning Electron Micrograph (SEM) of the surface of O composite, and FIG. 10(b) shows Au/Cu2Scanning Electron Micrograph (SEM) of the O-composite cross section.
As shown in FIG. 10(a), Au/Cu2The surface of the O composite material has a bicontinuous porous structure similar to that of example 1, and the pore size is about 20 nm. As shown in FIG. 10(b), Au/Cu2The cross section of the O composite material is different from the porous structure of example 1, and the O composite material has a particle stacking structure, and the particle size is about 50-100 nm.
Effects and effects of the embodiments
Au/Cu according to the above embodiments2The O composite material, the super-assembly preparation method and the application thereof are characterized in that firstly, metal aluminum, metal gold and metal copper are prepared into gold-copper-aluminum alloy according to a certain mass ratio, then dealuminization reaction is carried out in strong alkaline solution to obtain dealuminization alloy, further oxidation is carried out in the air to partially oxidize the copper, and Au/Cu is obtained2The method has simple preparation process, does not need to add a surfactant and is suitable for large-scale production.
Au/Cu according to the above embodiments2The super-assembly preparation method of the O composite material is characterized in that the gold copper aluminum alloy powder obtained in the step S3 is placed in ethanol and ultrapure water for ultrasonic cleaning, so that the purity of the product can be improved.
Au/Cu according to the above embodiments2The super-assembly preparation method of the O composite material comprises the step S4 of carrying out reaction under the magnetic stirring at the rotating speed of 1000 rpm-2000 rpm, so that the dealloying reaction efficiency can be improved, and the purity of the obtained dealloyed alloy material is higher.
Au/Cu according to the above embodiments2According to the super-assembly preparation method of the O composite material, the strong alkaline solution is a 2M sodium hydroxide solution, so that the stability of the copper element in the gold-copper-aluminum alloy powder can be unaffected on the basis of ensuring complete corrosion of the aluminum element in the gold-copper-aluminum alloy powder.
Au/Cu prepared in the above examples2O composite material because of Au/Cu2The O composite material is a nano material with a double-channel structure, and gaps among nano particles of the structural unit of the O composite material provide sufficient reaction space for the reaction of the lithium battery, so that the volume effect of an electrode can be well relieved in the charging and discharging processes of the battery, and the O composite material is helpful forThe multiplying power and the cycle performance are improved. And each structural unit consists of three-dimensional bicontinuous nanopores and has a high specific surface area, so that a rich three-phase reaction interface can be provided for the oxygen reduction reaction of the lithium battery. In addition Cu2O has good adsorbability to active oxygen atoms, and reduces the overpotential of the oxygen reduction reaction process to a certain extent (the report of inorganic chemistry, 2008,24, 340-; and Cu2O can be given to2The ability to provide electrons is relatively weak, and the ability to catalyze oxygen reduction reaction is strong (chem.Commun.,2012,48, 1892-1894).
Au/Cu obtained in the above examples2The O composite material can be used as a positive electrode catalytic material of a lithium-air battery, and the advantages of the alloy and the oxide can be combined, so that the electrochemical performance of a single material can be improved, the multiplying power and the cycle performance of the lithium-air battery can be improved, the consumption of noble metals can be reduced, and the cost can be saved.
The above embodiments are preferred examples of the present invention, and are not intended to limit the scope of the present invention.
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