Highly oriented zinc material, method for preparing the same and use thereof

Abstract

The application discloses a high-orientation zinc material, a preparation method and application thereof, and relates to the technical field of metal foil materials. The application provides a large and high-orientation zinc material 2 with a size greater than 30 cm, a thickness of 15-50 microns, and a relative texture coefficient greater than 90%. The high-orientation zinc material can be used as a substrate for electrodeposition epitaxy to induce the ordered growth of electrodeposits, and can be used as a negative electrode of a rechargeable zinc metal battery to simultaneously improve the thermodynamic and kinetic performance of the rechargeable zinc metal battery, so that the rechargeable zinc metal battery with a long cycle life and high reversibility is finally realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of zinc materials, in particular to a high-orientation zinc material, a preparation method and application thereof. BACKGROUND

[0002] Polycrystalline metals have a large number of grain boundaries that affect their (electro)chemical and mechanical properties, while high-orientation metals have fewer grain boundaries and exhibit different properties. For example, the electrical resistivity of high-orientation zinc metal is lower than that of polycrystalline zinc because it eliminates electron scattering; high-orientation high-temperature alloys have higher creep resistance, etc. Electrochemical deposition on high-orientation metal substrates to induce planar growth of electrodeposits has attracted widespread attention. Taking zinc metal materials as an example, certain substrates have low lattice mismatch with zinc [zinc and its alloys: <0.05%; cobalt: ~6%; titanium: ~9%], which can be used as substrates for crystal homoepitaxy or heteroepitaxy growth to achieve high reversibility of metal batteries. In addition, since large high-orientation metal foils have great potential applications in catalysis, energy storage and thermal engineering, the preparation of large high-orientation metal foils has been one of the key research directions in materials science.

[0003] There are mainly two methods for synthesizing high-orientation metal foils:

[0004] (1) Electrodeposition epitaxy method

[0005] In the process of epitaxial electrodeposition, the metal foil forms a coherent or semi-coherent lattice interface with the substrate. First, a single-crystal metal or inorganic substrate that matches the crystal face of the metal foil is prepared to minimize lattice strain; then the metal foil is electrodeposited epitaxially on the substrate at a certain current density, and the crystalline orientation of the metal foil is preferentially parallel to the substrate, forming a plate-like stacking structure.

[0006] The main problems of this method include: the substrate has very high requirements, not only to match the crystal face of the epitaxial metal foil, but also to exhibit sufficient (electro)chemical inertness to resist the electrolytic solution and the electrodeposition process. In addition, the current density and deposition time need to be strictly controlled during the epitaxial process, which is complex to operate. The high-orientation metal foils obtained by this method are usually expensive, small in size and uneven.

[0007] (2) Thermal annealing method

[0008] The process of annealing to manufacture high-orientation metal foils can be divided into two stages. First, an abnormal grain with a specific surface texture is formed by stamping or repeated rolling process. The size of the abnormal grain is much larger than that of other grains, which has the advantage of further growth. Then, the thermal annealing accelerates the growth of the abnormal grain, and finally promotes the formation of large high-orientation metal foils with specific texture.

[0009] The main problems of the above method include: the initial texture of the polycrystal foil greatly influences the high orientation metal foil. Specifically, if the proportion of abnormal grains in the initial foil is small, the rest of the grains are dense, and the grain boundary is dense, the grain boundary cannot be eliminated, and it is difficult to obtain an oriented metal foil. Therefore, this method can only transform part of the polycrystal region, and has not achieved high orientation of the entire metal foil. In addition, the annealing process is difficult to control, and the purity of the obtained oriented metal foil is low.

[0010] Therefore, it is urgent to develop a special preparation method to efficiently produce large high orientation metal foils.

[0011] In view of this, the present application is proposed. SUMMARY

[0012] The purpose of the present application is to provide a high orientation zinc material, a preparation method and application thereof, aiming to prepare a large high orientation zinc material.

[0013] The present application is implemented as follows:

[0014] In a first aspect, the present application provides a high orientation zinc material, which is tested by X-ray diffraction, and the relative texture coefficient of the high orientation zinc material is greater than 90%, wherein the formula of the relative texture coefficient is:

[0015]

[0016] In the formula, I (hkl) is the X-ray diffraction peak intensity of the highly oriented sample;

[0017] I 0(hkl) is the diffraction peak intensity of the standard sample.

[0018] In an optional embodiment, the high orientation zinc material is a zinc metal foil or a zinc alloy;

[0019] The zinc alloy is at least one of ZnAl, ZnCu, ZnSn, ZnIn and ZnSc alloy, and its composition includes: 3%-5% of alloying elements, and the balance is zinc.

[0020] In an optional embodiment, when the high orientation zinc material is a pure zinc metal foil, the preferred orientation crystal face is a zinc (0001) crystal face.

[0021] In an optional embodiment, the thickness of the high orientation zinc material is 15-50 μm, and the area is greater than 30 cm 2 ;

[0022] Preferably, the high orientation zinc material is tested by electron backscattering, and the proportion of the total number of preferred orientation grains is greater than 90%;

[0023] Preferably, the high-oriented zinc material is tested by transmission electron microscopy, only single crystal diffraction points exist.

[0024] In a second aspect, the present application provides a method for preparing the high-oriented zinc material according to any one of the preceding embodiments, comprising: preparing by vacuum melting, spray casting and tape casting.

[0025] In an optional embodiment, the method comprises: after the zinc metal raw material is heated and melted, the melt is sprayed onto the surface of a high-speed rotating rotating roller to perform directional rapid solidification.

[0026] Preferably, the rotating speed of the rotating roller is 15 m / s to 40 m / s; more preferably, 18 m / s to 22 m / s.

[0027] Preferably, the rotating roller is a copper roller.

[0028] In an optional embodiment, when the high-oriented zinc material is a pure zinc metal foil, the zinc metal raw material is selected from at least one of polycrystalline zinc metal foil, zinc particles and zinc ingot; preferably, the zinc metal raw material is zinc particles.

[0029] Preferably, the particle size of the zinc particles is 1 mm to 3 mm.

[0030] Preferably, when the high-oriented zinc material is a zinc alloy metal foil, the zinc metal raw material is selected from zinc alloy particles; preferably, the particle size of the zinc alloy particles is 1 mm to 10 mm.

[0031] In an optional embodiment, the zinc metal raw material is heated and melted by using a resistance heating coil in a furnace body, the spray casting pipe has a bottom spray port, the rotating roller is located below the bottom spray port, the pressure of the spray casting pipe is controlled to be greater than the pressure of the furnace body, and the pressure difference between the spray casting pipe and the furnace body is 10 kPa to 20 kPa, and the pressure in the furnace body is -60 kPa to -40 kPa.

[0032] Preferably, the inner diameter of the spray casting pipe is 15 mm to 20 mm, the height is 15 mm to 25 mm, the mass of the zinc metal raw material contained is 4 g to 8 g, the diameter of the rotating roller is 20 cm to 25 cm, and the thickness is 25 mm to 30 mm; the distance between the bottom spray port and the rotating roller is 0.8 mm to 2 mm.

[0033] Preferably, the bottom spray port is rectangular, the length of the bottom spray port is 12 mm to 16 mm, and the width is 0.2 mm to 0.8 mm.

[0034] Preferably, inert gas protection is introduced into the furnace body and the spray casting pipe.

[0035] Preferably, the spray casting pipe is a quartz tube, and the spray casting pipe is cleaned and dried before the zinc metal raw material is added.

[0036] In a third aspect, the application provides use of the highly oriented zinc material of any one of the preceding embodiments or the highly oriented zinc material prepared by the method of any one of the preceding embodiments as an electrodeposition epitaxial substrate.

[0037] In a fourth aspect, the application provides use of the highly oriented zinc material of any one of the preceding embodiments or the highly oriented zinc material prepared by the method of any one of the preceding embodiments as a negative electrode of a rechargeable zinc metal battery.

[0038] The application has the following beneficial effects: the application provides a large and highly oriented zinc material, which has a size greater than 30 cm 2 , a thickness of 15-50 μm, and a relative texture coefficient greater than 90%. The highly oriented zinc material can be used as an electrodeposition epitaxial substrate to induce ordered growth of electrodeposits; and can be used as a negative electrode of a rechargeable zinc metal battery to simultaneously improve its thermodynamic and kinetic performance, and finally realize a rechargeable zinc metal battery with long cycle life and high reversibility. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be considered as a limitation to the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0040] Figure 1 It is a schematic diagram of a high-vacuum suspension tape casting device;

[0041] Figure 2 It is a scanning electron microscope cross-section and a physical picture of the highly oriented zinc material prepared in Example 1.

[0042] Figure 3 It is an X-ray diffraction pattern of the highly oriented zinc material prepared in Example 1.

[0043] Figure 4 It is an atomic force microscope picture of the highly oriented zinc material prepared in Example 1.

[0044] Figure 5 It is a reverse pole picture of the highly oriented zinc material prepared in Example 1.

[0045] Figure 6 It is an electron diffraction pattern of the highly oriented zinc material prepared in Example 1. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0047] This invention provides a method for preparing a highly oriented zinc material, which can be zinc foil or zinc alloy. This invention employs a vacuum melting, spraying, and casting method, specifically including the following steps:

[0048] S1, molten zinc metal raw material

[0049] The zinc metal raw material is heated and melted, and the preparation can be carried out using an existing high-vacuum melting, spraying, and casting furnace during the operation.

[0050] Specifically, such as Figure 1 As shown, the high-vacuum melting and casting furnace is equipped with a resistance heating coil, a casting tube, and a rotating roller (i.e., the copper roller in the figure). The casting tube has a bottom injection port, and the rotating roller is located below the bottom injection port. The resistance heating coil in the furnace is used to heat and melt the zinc metal raw material. The rotating roller at room temperature can receive the zinc melt injected from the bottom of the casting tube and perform directional rapid solidification.

[0051] Furthermore, the casting tube can be a general quartz tube. After placing the zinc metal raw material into the quartz tube, adjust the position of the quartz tube to the center of the resistance heating coil. Evacuate the furnace body to a high vacuum (10). -3 A measured amount of argon gas is introduced into the quartz tube to ensure a pressure difference between the quartz tube and the furnace body, and the pressure inside the quartz tube must be greater than that inside the furnace body to achieve the spray casting effect. Then, the metal coil is heated to near the melting point of the zinc metal material (400℃~850℃) until the zinc metal raw material is completely melted.

[0052] In some embodiments, when the highly oriented zinc material is pure zinc foil, the zinc metal raw material is selected from at least one of polycrystalline zinc foil, zinc particles, and zinc ingots. All of these are commercially available raw materials, and the zinc metal raw material can be any one or more of them; preferably, it is zinc particles. The inventors have found that zinc foil prepared using zinc particles has a higher degree of orientation, possibly due to the higher purity of the zinc particles. The particle size of the zinc particles is 1mm to 3mm, such as 1mm, 2mm, 3mm, etc.

[0053] In some embodiments, when the highly oriented zinc material is a zinc alloy foil, the zinc metal raw material is selected from zinc alloy particles, and the particle size is 1-10 mm irregular particles.

[0054] In some embodiments, the spray casting tube is cleaned and dried before the zinc metal raw material is added to prevent the introduction of impurities. Specifically, the spray casting tube is a quartz tube with a flat bottom, which is first cleaned with deionized water for 10-20 minutes, and then cleaned with ethanol for 10-20 minutes to obtain a clean quartz tube; the cleaned glass bottle is placed in a drying oven, the temperature is set to 60-80°C, and the glass bottle is taken out after drying for 20-40 minutes.

[0055] In some embodiments, the outer diameter of the spray casting tube is 18-25 mm, the inner diameter is 15-20 mm, and the height is 15-25 mm; the bottom spray port is rectangular, the length of the bottom spray port is 12-16 mm, and the width is 0.2-0.8 mm. The outer diameter of the spray casting tube can be 18 mm, 20 mm, 25 mm, etc., the inner diameter of the spray casting tube can be 15 mm, 17 mm, 20 mm, etc., and the height of the spray casting tube can be 15 mm, 20 mm, 25 mm, etc.; the length of the bottom spray port can be 12 mm, 14 mm, 16 mm, etc., and the width can be 0.2 mm, 0.5 mm, 0.8 mm, etc.

[0056] Further, under the above size conditions, the mass of the zinc metal raw material added into the spray casting tube is 4-8 g, the diameter of the rotating roller is 20-25 cm, and the thickness is 25-30 mm; the distance between the bottom spray port and the rotating roller is 0.8-2 mm. By further controlling the specific parameters, the uniformity of the prepared foil can be improved. Specifically, the mass of the zinc metal raw material added into the spray casting tube can be 4 g, 6 g, 8 g, etc., and the distance between the bottom spray port and the rotating roller can be 0.8 mm, 1.0 mm, 1.5 mm, 2.0 mm, etc. The diameter of the rotating roller can be 20 cm, 21 cm, 22 cm, 23 cm, 24 cm, 25 cm, etc., and the thickness can be 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, etc.

[0057] In some embodiments, the pressure of the spray casting tube is controlled to be greater than the pressure of the furnace body, and the pressure difference between the spray casting tube and the furnace body is 10-20 kPa, the pressure in the furnace body is -60 to -40 kPa, and inert gas protection is introduced into the furnace body and the spray casting tube. Under the condition of high vacuum, the material is prevented from being oxidized by cooperating with inert gas. Specifically, the inert gas can be nitrogen, argon, etc., and the specific type is not limited.

[0058] S2, spray casting and tape casting

[0059] The melt is sprayed onto the surface of a high-speed rotating rotating roller at a certain pressure to perform directional rapid solidification, thereby generating preferential in-plane crystal orientation and out-of-plane crystal orientation, accompanied by the consumption of transverse grain boundaries and adjacent grains, so as to minimize the surface energy, thereby driving the growth of large high-oriented metal grains.

[0060] For the metal zinc, the surface energy is the main driving force for the growth of the close-packed hexagonal grains of the polycrystalline metal, and other crystal planes are spontaneously transformed into the (0001) plane due to the minimization of the surface energy, thereby forming a large-area (0001) high-oriented zinc grain.

[0061] In some embodiments, the rotating speed of the rotating roller is 15-40 m / s, and more preferably 18-22 m / s. The rotating speed of the rotating roller is precisely controlled to further improve the orientation degree of the zinc metal foil. Specifically, the rotating speed of the rotating roller can be 15 m / s, 18 m / s, 20 m / s, 22 m / s, 25 m / s, 30 m / s, 35 m / s, 40 m / s, etc. The rotating roller can be a copper roller, but is not limited thereto.

[0062] It should be noted that the preparation method of the high-oriented zinc material provided by the embodiments of the present application is simple and easy to operate, and a cheap and easily available high-oriented zinc material is obtained. The preparation of a large high-oriented zinc material is realized for the first time, and the problems of high cost, small size, low purity, and non-uniformity in the preparation of zinc metal foils in the prior art are solved.

[0063] The embodiments of the present application also provide a high-oriented zinc material. In X-ray diffraction characterization, the orientation degree of the zinc metal foil is measured by using a relative texture coefficient, and the relative texture coefficient is greater than 90%. Generally, when the peak intensity ratio is greater than 10%, it is a high orientation, and the greater the orientation degree is. The high-oriented zinc material prepared by the embodiments of the present application is greater than 90%.

[0064] Specifically, the formula of the relative texture coefficient is:

[0065]

[0066] In the formula, I (hkl) is the XRD diffraction peak of the high-oriented sample; I 0(hkl) is the diffraction peak intensity of the standard sample.

[0067] It should be noted that the high-oriented zinc material in the embodiments of the present application can be a pure zinc metal foil or a zinc alloy. The zinc alloy is at least one of ZnAl, ZnCu, ZnSn, ZnIn, and ZnSc alloy, and the composition includes 3-5% of alloying elements and the balance of zinc in terms of mass percentage. The alloying elements can be Al, Cu, Sn, In, Sc, etc.

[0068] When the high-oriented zinc material is a pure zinc metal foil, the preferred crystal plane of the high-oriented zinc material is the zinc (0001) crystal plane.

[0069] In some embodiments, the thickness of the high-oriented zinc material is 15-50 μm, and the area is greater than 30 cm 2The high-orientation zinc material is a large and high-orientation zinc material. It is worth noting that the upper limit of the area of the high-orientation zinc material is not limited, and a larger size of the high-orientation zinc material can be obtained by adjusting the size of the copper roller.

[0070] In some embodiments, the high-orientation zinc material is tested by a backscattered electron microscope, and the proportion of the preferentially oriented grains is greater than 90%, and at least 50 or more grains are included in the inverse pole figure. By controlling the parameters, the proportion of the high-orientation grains prepared by the embodiments of the present application can be greater than 98%.

[0071] In some embodiments, the high-orientation zinc material is tested by a transmission electron microscope, and only single-crystal diffraction points exist, without other diffraction rings or diffuse spots. The high-orientation zinc material prepared by the embodiments of the present application only has diffraction points.

[0072] The embodiments of the present application also provide the application of the above-mentioned high-orientation zinc material as an electrodeposition epitaxial substrate, which can be used as a substrate for large-scale electrodeposition epitaxy to induce the layer-by-layer growth of the electrodeposited material.

[0073] The embodiments of the present application also provide the application of the above-mentioned high-orientation zinc material as a negative electrode of a rechargeable zinc metal battery, which can be used to prepare a highly reversible zinc metal battery. Specifically, the large zinc orientation metal foil prepared by the embodiments of the present application is uniform, dense and moderate in thickness, which has obvious advantages as a metal negative electrode.

[0074] Specifically, compared with a polycrystalline zinc metal foil, the thermodynamic properties of the high-orientation zinc electrode are greatly improved, and the electrode has very excellent stability, which can significantly inhibit electrode corrosion and side reactions. In addition, due to the few grain boundaries, the electrode kinetics is significantly improved, and a highly reversible and long-circulation zinc metal battery can be prepared.

[0075] The features and performances of the present application are further described in detail in the following embodiments.

[0076] The high-vacuum melting and casting spin casting furnace used in the following embodiments is a CMT-RQT100.

[0077] Embodiment 1

[0078] The present embodiment provides a preparation method of a high-orientation zinc material, which comprises the following steps:

[0079] (1) Melting zinc metal raw material

[0080] A quartz tube with a flat bottom is selected, and the size of the quartz tube is about 20 mm in outer diameter, about 17 mm in inner diameter, and about 140 mm in height. The opening of the bottom of the quartz tube is about 14 mm long and about 0.5 mm wide. The roller is a copper roller with a diameter of 21.96 cm and a thickness of 28 mm.

[0081] The quartz tube is cleaned by ultrasonic cleaning with deionized water for 15 minutes and then with ethanol for 15 minutes to obtain a clean quartz tube; the cleaned quartz tube is placed in a drying box, and the temperature is set to 70°C; the quartz tube is taken out after drying for 30 minutes.

[0082] 6 g of zinc particles with a particle size of about 2 mm are placed in the quartz tube, the quartz tube is adjusted to be located at the center of the coil, the nozzle is 0.8 mm away from the copper roller, and the quartz tube is screwed and fixed. The bottom of the nozzle is located below the coil, and the furnace door is closed.

[0083] The mechanical pump is started, the pre-evacuation valve is opened, the pressure gauge is set to 0 Pa, the front-stage valve is opened after the pressure gauge is set to 0 Pa, and the vacuum is pumped to below 10 Pa. The diffusion pump is started, and is preheated for 50 minutes. The pre-evacuation valve is closed, the main evacuation valve is opened, and the vacuum is pumped to 10 Pa. -3 Pa high vacuum. The main evacuation valve is closed, and argon is filled into the furnace body and the quartz tube until the difference between the indicated numbers in the gas cylinder and the cavity is 15 kPa. The vacuum indicated number in the gas cylinder is -35 kPa, and the vacuum indicated number in the furnace body is -50 kPa;

[0084] The heating power switch is turned on, the temperature is adjusted to 450°C, and the zinc metal raw material is heated for 10 seconds until it is melted and whitened.

[0085] (2) Spray casting and strip casting process

[0086] The servo power is turned on, the copper roller is started, and the rotating speed of the copper roller is adjusted to 20 m / s. The spray casting button is pressed, the nozzle is raised to the highest position after the metal foil strip casting is completed. The heating power, the copper roller switch, and the servo power are sequentially turned off. The gas valve is opened, and the furnace door is opened, and then the metal foil can be taken out.

[0087] The scanning electron microscope cross-section and the actual picture of the zinc metal foil prepared in the embodiment of the application are tested, as shown in Figure 2 From Figure 2 it can be seen that the thickness of the metal foil is 20 μm, and the area is greater than 30 cm 2 .

[0088] The X-ray diffraction pattern of the zinc metal foil prepared in the embodiment of the application is tested, as shown in Figure 3 From Figure 3 it can be seen that the peak height of the zinc (0001) crystal plane is much higher than that of other crystal planes, the relative texture coefficient is greater than 90%, and the orientation degree is high.

[0089] The atomic force microscope picture of the zinc metal foil prepared in the embodiment of the application is tested, as shown in Figure 4 From Figure 4 it can be seen that the surface of the zinc metal foil is smooth and is composed of a large number of texture particles with a diameter of microns.

[0090] The reverse pole figure of the zinc metal foil prepared in the embodiment of the application is tested, as shown in Figure 5 FromFigure 5 It can be seen that the proportion of zinc grains with preferred orientation is greater than 98%, indicating that the metal foil is a uniform, highly oriented crystal.

[0091] The transmission electron microscopy and electron diffraction patterns of the zinc metal foil prepared in the embodiments of the present invention were tested, as shown in the figure. Figure 6 As shown. From Figure 6 It can be seen that the zinc foil has a hexagonal close-packed crystal structure and the diffraction pattern is a single crystal diffraction pattern.

[0092] Example 2

[0093] This embodiment provides a method for preparing a highly oriented zinc material, which differs from Embodiment 1 only in that: in step (1), the zinc metal raw material is polycrystalline zinc metal foil.

[0094] Example 3

[0095] This embodiment provides a method for preparing highly oriented zinc material, which differs from Embodiment 1 only in that: in step (1), the zinc metal raw material is zinc ingot.

[0096] Example 4

[0097] This embodiment provides a method for preparing a highly oriented zinc material, which differs from Embodiment 1 only in that: in step (1), the bottom opening width of the quartz tube is 0.2 mm.

[0098] Example 5

[0099] This embodiment provides a method for preparing a highly oriented zinc material, which differs from Embodiment 1 only in that: in step (1), the bottom opening width of the quartz tube is 0.8 mm.

[0100] Example 6

[0101] This embodiment provides a method for preparing highly oriented zinc material, which differs from Embodiment 1 only in that: in step (1), the pressure difference between the casting pipe and the furnace body is 10 kPa, and the pressure inside the furnace body is -50 kPa;

[0102] Example 7

[0103] This embodiment provides a method for preparing highly oriented zinc material, which differs from Embodiment 1 only in that: in step (1), the pressure difference between the casting pipe and the furnace body is 20 kPa, and the pressure inside the furnace body is -50 kPa;

[0104] Example 8

[0105] This embodiment provides a method for preparing highly oriented zinc material, which differs from Embodiment 1 only in that: in step (2), the copper roller speed is 15 m / s.

[0106] Example 9

[0107] This example provides a method for preparing a highly oriented zinc material, which differs from Example 1 only in that in step (2), the copper roll rotation speed is 30 m / s.

[0108] Example 10

[0109] This example provides a method for preparing a highly oriented zinc material, which prepares a highly oriented ZnAl alloy, which differs from Example 1 only in that in step (1), the zinc metal raw material is a ZnAl alloy, which consists of 5% aluminum and the balance zinc by mass percentage; and in step (2), the melting temperature is adjusted to 650°C.

[0110] Example 11

[0111] This example provides a method for preparing a highly oriented zinc material, which prepares a highly oriented ZnCu alloy, which differs from Example 1 only in that in step (1), the zinc metal raw material is a ZnCu alloy, which consists of 3% alloying elements and the balance zinc; and in step (2), the melting temperature is adjusted to 700°C.

[0112] Example 12

[0113] This example provides a method for preparing a highly oriented zinc material, which prepares a highly oriented ZnSn alloy, which differs from Example 1 only in that in step (1), the zinc metal raw material is a ZnSn alloy, which consists of 10% alloying elements and the balance zinc; and in step (2), the melting temperature is adjusted to 380°C.

[0114] Example 13

[0115] This example provides a method for preparing a highly oriented zinc material, which prepares a highly oriented ZnIn alloy, which differs from Example 1 only in that in step (1), the zinc metal raw material is a ZnIn alloy, which consists of 8% alloying elements and the balance zinc; and in step (2), the melting temperature is adjusted to 400°C.

[0116] Example 14

[0117] This example provides a method for preparing a highly oriented zinc material, which prepares a highly oriented ZnSc alloy, which differs from Example 1 only in that in step (1), the zinc metal raw material is a ZnSc alloy, which consists of 5% alloying elements and the balance zinc; and in step (2), the melting temperature is adjusted to 850°C.

[0118] Comparative Example 1

[0119] The present comparative example provides a conventional method for preparing a zinc metal foil, which is prepared by an electrodeposition epitaxy method. The specific operation steps are as follows: a commercial single-crystal copper (111) metal foil is used as a positive electrode, a commercial polycrystalline zinc metal foil is used as a negative electrode, and a 2M zinc sulfate aqueous solution is used as an electrolyte, and electrodeposition epitaxy is carried out in an electrolytic cell. The current density is controlled to be 10 mA cm -2 , and the deposition surface capacity is 1 mAh cm -2 . Zinc is deposited on the surface of the single-crystal copper (111). After the electrodeposition is completed, the metal foil is taken out, washed with deionized water for 3 times, and dried at room temperature.

[0120] Comparative Example 2

[0121] The present comparative example provides a conventional method for preparing a zinc metal foil, which is prepared by an annealing method. The specific operation steps are as follows: first, a 100 μm commercial polycrystalline metal foil is folded and rolled to 20 μm by a rolling mill for 5 times. Then, the metal foil is placed in a high-vacuum tube furnace, 5% hydrogen-argon mixed gas is filled, and 700°C thermal annealing is carried out for 3 h. Subsequently, the metal foil is taken out after being cooled to room temperature.

[0122] Comparative Example 3

[0123] The present comparative example is a commercial polycrystalline zinc metal foil.

[0124] Test Example 1

[0125] The basic parameters of the zinc metal foils prepared in the test examples and comparative examples are tested, and the results are shown in Table 1.

[0126] Table 1: Summary of the basic parameters of the zinc metal foils prepared in the test examples and comparative examples

[0127]

[0128] As can be seen from Table 1, the zinc metal foils prepared in the embodiments of the present application have large size, high orientation degree, and good uniformity, and have obvious advantages compared with the conventional electrodeposition epitaxy method and the thermal annealing method. Specifically:

[0129] (1) The high-oriented zinc metal foil prepared in the embodiments of the present application has a thickness of 15-50 μm, and an area of more than 30 cm 2 . The metal foil prepared by the conventional electrodeposition epitaxy method (Comparative Example 1) has a thickness of only 5.8 μm and an area of only 1 cm 2 . The metal foil prepared by the thermal annealing method (Comparative Example 2) has a thickness of 20 μm and an area of 10 cm. It is worth noting that the upper limit of the area of the metal foil prepared by the present method is not limited, and a larger size of the zinc metal foil can be obtained by adjusting the size of the copper roller. In addition, the zinc and zinc alloy metal foils prepared in the embodiments of the present application all have high orientation degree.

[0130] (2) The relative texture coefficient is used to measure the degree of orientation of the zinc metal foil. Generally, the peak intensity ratio is greater than 10%, which is highly oriented, and the greater the orientation, the higher the degree of orientation. The high-orientation zinc metal foil prepared by the embodiment of the present application is greater than 90%, which is much higher than that of Comparative Example 1 (70%), Comparative Example 2 (15%) and Comparative Example 3 (5%). Among them, Comparative Example 3 is a polycrystalline zinc metal foil.

[0131] (3) The high-orientation zinc metal foil is tested by a backscattered electron microscope. The proportion of the preferred orientation grain is greater than 90%, and at least 50 or more grains are included in the inverse pole figure. By controlling the parameters, the proportion of the high-orientation grain prepared by the embodiment of the present application can be greater than 98%, which is much higher than that of the comparative examples.

[0132] (4) The high-orientation zinc material is tested by a transmission electron microscope. Only single-crystal diffraction points exist, and no other diffraction rings or diffuse spots exist. The high-orientation zinc material prepared by the embodiment of the present application only has diffraction points. The metal foils prepared by Comparative Examples 2 and 3 have polycrystalline diffraction, indicating that the purity of the metal foils is low and the degree of orientation is poor.

[0133] (5) The high-orientation zinc metal foil is prepared by a vacuum melting and spray casting method. The main influencing factors include zinc raw materials, the opening width of the bottom of the quartz tube, the pressure difference between the spray casting tube and the furnace body, and the copper roller speed. Through the comparative examples, it is found that in order to obtain high-quality high-orientation zinc metal foil, the zinc metal raw material is preferably 2 mm pure zinc particles or 1-10 mm zinc alloy particles, the opening width of the bottom of the quartz tube is preferably 0.5 mm, the pressure difference between the spray casting tube and the furnace body is preferably 15 kPa, and the copper roller speed is preferably 20 m / s.

[0134] Test Example 2

[0135] The zinc metal foils prepared by the embodiments and comparative examples are used as substrates for large-scale electrodeposition epitaxy. Taking the epitaxial electrodeposition of metal zinc as an example, the basic parameters of the epitaxial layer are tested.

[0136] Test method: A polycrystalline zinc metal foil with a size of 2*3 cm is used as a negative electrode, and a high-orientation zinc material with a size of 1*3 cm is used as a positive electrode. The electrolyte is a 2M zinc sulfate aqueous solution, and the electrolytic cell is assembled for electrodeposition epitaxy. The current density is controlled to be 50 mA cm -2 , and the deposition surface capacity is 50 mAh cm -2 . Zinc is deposited on the surface of the high-orientation zinc metal foil. The zinc metal foil obtained by electrodeposition epitaxy is characterized and tested, and the test results are shown in Table 2.

[0137] Table 2 Summary table of parameters of epitaxial zinc foil obtained by using the electrodeposition substrates of embodiments and comparative examples

[0138]

[0139] As shown in Table 2, a higher substrate orientation degree results in a smaller lattice mismatch, a thinner electrodeposited epitaxial zinc metal thickness, and a higher density. The zinc metal foil prepared in this embodiment of the invention, used as a substrate for large-scale electrodeposited epitaxy, has an epitaxial zinc metal density of 6.17–7.08 g / cm³. -3 Its theoretical mass density (7.14 g cm³) -3 The results are very close, indicating that the epitaxial layer is densely packed and of high quality. The epitaxial layer densities of Comparative Example 1, Comparative Example 2, and Comparative Example 3 are 4.56 g / cm³, respectively. -3 2.13g cm -3 and 0.87g cm -3 Low epitaxial deposition density indicates loose electrodeposition with numerous pores, resulting in poor epitaxial performance. Comparative Example 3, in particular, did not meet the conditions for epitaxial growth.

[0140] Therefore, the zinc metal foil prepared in the embodiments of the present invention has obvious advantages as a substrate for large-scale electrodeposition epitaxial growth and can induce the orderly growth of electrodeposited materials.

[0141] Experimental Example 3

[0142] The zinc metal foils prepared in the examples and comparative examples were used as negative electrodes of rechargeable zinc metal batteries to test battery performance.

[0143] Test method: Highly oriented zinc material with a diameter of 16 cm was used as the negative electrode, and highly oriented zinc material or polycrystalline titanium foil with a diameter of 16 cm was used as the positive electrode. The electrolyte was a 2M zinc sulfate aqueous solution, and the separator was glass fiber. The cells were assembled into zinc metal symmetric cells or half-cells. The performance of the assembled cells was tested, and the test results are shown in Table 3.

[0144] Performance parameter testing methods:

[0145] (1) Corrosion current: Tafel testing was performed using a zinc symmetric cell. The starting voltage was set to -0.25V, the ending voltage to 0.25V, and the scan rate to 1mV / s.

[0146] (2) Exchange current density: A variable current charge-discharge test was conducted using a zinc symmetrical battery. Current densities were set to 0.2, 0.5, 1, 2, and 5 mA / cm². -2 The corresponding deposition surface capacities are 0.2, 0.5, 1, 2, and 5 mAh cm⁻¹. -2 After 5 cycles each, the formula for calculating the exchange current density is as follows:

[0147]

[0148] Where i0 is the exchange current density, I is the current density, F is the Faraday constant, η is the overpotential, R is the molar gas constant, and T is the temperature.

[0149] (3) Coulombic efficiency: The Coulombic efficiency was tested by using zinc-titanium half-cell. The current density was set as 1 mA cm -2 , the deposition surface capacity was 1 mAh cm -2 , and the cut-off voltage was 1 V.

[0150] (4) Cycle life: The constant current charge-discharge test was performed by using zinc symmetric cell. The current density was set as 1 mA cm -2 , and the deposition surface capacity was 1 mAh cm -2 .

[0151] Table 3: Summary of performance parameters of zinc metal batteries prepared by examples and comparative examples

[0152]

[0153]

[0154] As can be seen from Table 3, the zinc metal foil prepared by the examples of the present application as the negative electrode of the rechargeable zinc metal battery has the following advantages:

[0155] (1) High thermodynamic stability: The corrosion current is reduced from 0.42 mA cm -2 to 0.10-0.15 mA cm -2 , indicating that the zinc metal foil prepared by the examples of the present application is stable in thermodynamics and more resistant to corrosion.

[0156] (2) Fast reaction kinetics: The kinetics of the zinc metal foil prepared by the examples of the present application is measured by exchange current density. Generally, the higher the current density, the faster the ion transfer and reaction speed. The exchange current density of the high-orientation zinc material is as high as 7.2-9.2 mA cm -2 , which is significantly higher than that of other comparative examples, indicating that the electrode reaction has extremely fast kinetics.

[0157] (3) High Coulombic efficiency: Under different current densities, the average Coulombic efficiency of the zinc metal foil prepared by the examples of the present application is 98.6%, which is 1.5%, 1.8% and 2.3% higher than that of comparative example 1, comparative example 2 and comparative example 3, respectively, indicating excellent cycle reversibility.

[0158] (4) Long cycle life: In the symmetric cell, under the medium test conditions (1 mA cm -2 current density, 1 mAh cm -2 surface capacity, corresponding to a discharge depth of about 10.8%), it can be stably cycled for more than 2000 h; under more severe and practical test conditions (10 mA cm -2 current density, 5 mAh cm -2The capacity retention rate is stable for 720 hours at 51% discharge depth. The above values are significantly higher than the comparative examples, especially, the cycle life is increased by nearly 30 times compared with comparative example 3, and the above performances are the highest values reported in the literature under the same test conditions.

[0159] The above is only a preferred embodiment of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of producing a highly oriented zinc material, characterized by, The application relates to a preparation method of a high-orientation zinc material. The high-orientation zinc material is prepared by vacuum melting, spray casting and strip casting; After the zinc metal raw material is heated and melted, the melt is sprayed onto the surface of a high-speed rotating rotating roller to realize directional rapid solidification, so that the high-orientation zinc material is obtained; The rotating speed of the rotating roller is 15-40 m / s. When the high-orientation zinc material is a zinc metal foil, the zinc metal raw material is selected from at least one of polycrystalline zinc metal foil, zinc particles and zinc ingot; when the high-orientation zinc material is a zinc alloy metal foil, the zinc metal raw material is selected from zinc alloy particles. The zinc metal raw material is heated and melted by using a resistance heating coil in a furnace body, the spray casting pipe has a bottom spray port, the rotating roller is located below the bottom spray port, the pressure of the spray casting pipe is controlled to be greater than the pressure of the furnace body, the pressure difference between the spray casting pipe and the furnace body is 10-20 kPa, and the pressure in the furnace body is -60 to -40 kPa. The high-orientation zinc material is tested by X-ray diffraction, and the relative texture coefficient is greater than 90%, wherein the formula of the relative texture coefficient is: ； wherein I (hkl) X-ray diffraction peak intensity for highly oriented samples; I 0(hkl) The peak intensity of the diffraction peak of the standard sample.

2. The production method according to claim 1, characterized by, The rotating speed of the rotating roller is 18-22 m / s.

3. The preparation method according to claim 1, characterized in that, The rotating roller is a copper roller.

4. The method of claim 1, wherein, The zinc metal raw material is zinc particles.

5. The production method according to claim 4, characterized by, The particle size of the zinc particles is 1-3 mm.

6. The method of claim 1, wherein, The particle size of the zinc alloy particles is 1-10 mm.

7. The preparation method according to claim 1, characterized in that, The inner diameter of the spray casting pipe is 15-20 mm, the height is 15-25 mm, the mass of the zinc metal raw material contained in the spray casting pipe is 4-8 g, the diameter of the rotating roller is 20-25 cm, and the thickness is 25-30 mm; the distance between the bottom spray port and the rotating roller is 0.8-2 mm.

8. The preparation method according to claim 7, characterized in that, The bottom spray port is a rectangle, the length of the bottom spray port is 12-16 mm, and the width is 0.2-0.8 mm.

9. The method of claim 1, wherein, Inert gas protection is introduced into the furnace body and the spray casting pipe.

10. The method of claim 9, wherein, The spray casting pipe is a quartz pipe, and the spray casting pipe is cleaned and dried before the zinc metal raw material is added.

11. A highly oriented zinc material produced by the production method according to any one of claims 1 to 10, characterized in that, The high-orientation zinc material is tested by X-ray diffraction, and the relative texture coefficient is greater than 90%, wherein the formula of the relative texture coefficient is: ； wherein I (hkl) X-ray diffraction peak intensity for highly oriented samples; I 0(hkl) Intensity of the diffraction peak for the standard sample; When the high-orientation zinc material is a pure zinc metal foil, the orientation crystal face is a zinc (0001) crystal face.

12. The highly oriented zinc material of claim 11, wherein, The high-orientation zinc material is a zinc or zinc alloy metal foil. The zinc alloy is at least one of ZnAl, ZnCu, ZnSn, ZnIn and ZnSc alloy, and the composition includes 3-5% of alloy elements and the balance of zinc.

13. The highly oriented zinc material of claim 11 or 12, wherein, The high-orientation zinc material has a thickness of 15-50 μm and an area of more than 30 cm 2 .

14. The highly oriented zinc material of claim 13, wherein, The high-orientation zinc material is tested by electron back scattering, and the proportion of the total number of zinc (0001) crystal grains is greater than 90%.

15. The highly oriented zinc material of claim 14, wherein, The high-orientation zinc material is tested by transmission electron microscopy, and only single crystal diffraction points exist.

16. The application of the high-orientation zinc material prepared by the preparation method in any one of claims 1-10 or the high-orientation zinc material in any one of claims 11-15 as an electrodeposition epitaxial substrate.

17. Use of a high oriented zinc material produced by the method of any one of claims 1-10 or any one of claims 11-15 as a negative electrode for a rechargeable zinc metal battery.

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