Single crystal zinc negative electrode, preparation method and application of single crystal zinc negative electrode in assembling high-performance zinc battery

Abstract

The invention provides a single-crystal zinc negative electrode, a preparation method and application of the single-crystal zinc negative electrode in assembling a high-performance zinc battery, and the preparation method of the single-crystal zinc negative electrode comprises the following steps: S1, cutting, cleaning and drying a brass foil to obtain a brass foil substrate; s2, placing the brass foil substrate in a central area of a tubular furnace, and preparing reactants of copper acetylacetonate and chloranil; s3, inert gas is introduced into the tubular furnace, the furnace temperature is increased to 300-500 DEG C, the temperature is kept for 1.5-2.5 h so as to drive the deposition reaction of the Cu3 (C6O6) 2 thin film, after the reaction is completed, the copper foil substrate is cooled to the room temperature, and the brass foil substrate with the synthesized Cu3 (C6O6) 2 thin film is taken out; and S4, assembling the brass foil substrate synthesized with the Cu3 (C6O6) 2 thin film in a button cell to serve as a working electrode, and depositing a zinc layer on the surface of the Cu3 (C6O6) 2 thin film through an electro-deposition method to obtain the single crystal zinc negative electrode with single crystal face exposure.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc metal batteries, and in particular to a single crystal zinc negative electrode, a preparation method and application thereof in assembling a high-performance zinc battery. Background Art

[0002] In recent years, lithium-ion battery technology has been increasingly improved and has become a leader in the new generation of electrochemical energy storage. However, the organic electrolytes currently used in commercial lithium-ion batteries have the risk of being flammable, which has brought significant application obstacles and safety hazards to lithium batteries. In addition, the high cost of lithium metal and the uneven distribution of resources have also limited the rapid promotion of lithium batteries in large-scale energy storage applications.

[0003] Thanks to its high specific capacity and excellent safety performance, aqueous zinc-ion batteries have attracted much attention in the current energy shortage environment. The zinc metal negative electrode has the advantages of low cost, non-toxicity and high specific capacity. Its volume specific capacity has even reached 5855mAh / cm 3 , far exceeding the lithium metal anode (2061mAh / cm 3 ), thus showing a very high application prospect. However, the electrochemical reaction of zinc negative electrode in aqueous electrolyte is currently unstable, and it is easy to cause side reactions such as corrosion and hydrogen evolution at the negative electrode / electrolyte interface, forming low ionic conductivity compounds such as zinc oxide and zinc hydroxide, thereby reducing the cycle life of zinc batteries.

[0004] Studies have shown that compared to zinc and The zinc (0002) crystal plane shows the lowest surface energy and the slowest hydrogen evolution reaction rate, and can guide the deposition / nucleation of solvated zinc ions. However, commercial zinc plates show the exposure of multiple crystal plane components. The insertion / extraction of zinc ions will produce lattice distortion, ultimately leading to rapid capacity decay and battery failure. Therefore, maintaining the exposure of a single crystal plane can maintain the high performance of the zinc negative electrode, but there are still many challenges. Summary of the invention

[0005] The present invention is made to solve the above-mentioned problems, and aims to provide a single crystal zinc negative electrode, a preparation method and application thereof in aqueous zinc batteries.

[0006] The present invention provides a method for preparing a single crystal zinc negative electrode, which has the following characteristics and comprises the following steps:

[0007] Step S1, cutting, cleaning and drying the brass foil to obtain a brass foil substrate;

[0008] Step S2, placing a brass foil substrate in the central area of ​​the tube furnace, preparing reactants copper acetylacetonate and chloranil, placing the copper acetylacetonate in the upstream part of the tube furnace, and placing chloranil in the downstream part to ensure that the reactants are evenly distributed;

[0009] Step S3, introducing an inert gas into the tube furnace, gradually raising the furnace temperature to 300-500°C, and maintaining the temperature for 1.5-2.5 hours to drive the deposition reaction of the Cu3(C6O6)2 film. After the reaction is completed, gradually cooling to room temperature, and taking out the brass foil substrate on which the Cu3(C6O6)2 film has been synthesized;

[0010] Step S4: Assemble the brass foil substrate on which the Cu3(C6O6)2 thin film has been synthesized in a button cell as a working electrode, and deposit a zinc layer on the surface of the Cu3(C6O6)2 thin film by electrodeposition to obtain a single crystal zinc negative electrode with a single crystal plane exposure.

[0011] The method for preparing the single crystal zinc negative electrode provided by the present invention may also have the following feature: wherein the furnace temperature in step S3 is 300°C.

[0012] The method for preparing the single crystal zinc negative electrode provided by the present invention may also have the following feature: wherein the furnace temperature in step S3 is maintained for 2 hours.

[0013] The method for preparing the single crystal zinc negative electrode provided by the present invention may also have the following characteristics: wherein the mass ratio of copper acetylacetonate to chloranil is 1:(0.2-0.3).

[0014] The method for preparing the single crystal zinc negative electrode provided by the present invention may also have the following characteristics: wherein the rare gas introduced into the tubular furnace is argon, and the argon flow rate is set to 2-5 L / min to ensure that the atmosphere in the reaction zone is pure and oxygen-free.

[0015] The present invention also provides a single crystal zinc negative electrode having the following characteristics, which is prepared by a method for preparing a single crystal zinc negative electrode.

[0016] The single crystal zinc negative electrode provided by the present invention may also have the following characteristics: wherein, the single crystal zinc negative electrode includes a brass foil substrate, a Cu3(C6O6)2 thin film synthesized on the brass foil substrate, and a zinc layer deposited on the surface of the Cu3(C6O6)2 thin film by electrodeposition.

[0017] The present invention also provides an application of a single crystal zinc negative electrode in assembling a high-performance zinc battery.

[0018] In the application of the single crystal zinc negative electrode provided by the present invention in assembling a high-performance zinc battery, the zinc battery used for assembly includes a zinc-copper half-cell, a zinc symmetrical cell and a zinc-manganese dioxide full cell. When the battery used for assembly is a zinc symmetrical cell, 1 mA cm -2 、1mAh cm -2 When the battery used for assembly is a zinc-copper half-cell, 10 mA cm -2 Conditions; when the battery used for assembly is a zinc manganese dioxide full battery, the conditions of 1.47Ah and 1A / g current are selected.

[0019] In the application of the single crystal zinc negative electrode provided by the present invention in assembling a high-performance zinc battery, it can also have the following characteristics: wherein, the single crystal zinc negative electrode is used as the negative electrode material of the zinc metal battery, the electrolyte is a zinc sulfate aqueous electrolyte, and during the battery cycle of the zinc battery electrolyte, the zinc ions in the zinc salt are regulated by the single crystal zinc negative electrode to form a dense zinc deposit on the brass substrate.

[0020] Functions and Effects of the Invention

[0021] According to the single crystal zinc negative electrode, preparation method and application in aqueous zinc battery involved in the present invention, the metal organic framework material Cu3(C6O6)2 is deposited on the brass substrate by vapor deposition, and the low lattice mismatch between the brass substrate and the deposited zinc layer is utilized to effectively promote the zinc atoms in the electroplated zinc layer to be arranged in order along the (0002) crystal plane, significantly improving the uniformity of the zinc negative electrode surface, reducing the orientation difference and lattice distortion between different crystal planes. The preferential exposure of this single crystal plane reduces the surface energy of the zinc negative electrode, helps to achieve a stable zinc ion deposition / stripping process, and prolongs the service life of the battery.

[0022] The ordered porous Cu3(C6O6)2 film of the present invention provides a fast transmission channel for zinc ions and reduces the overpotential of zinc ions during the deposition process. This design effectively reduces the nucleation barrier of zinc ions, prevents the disordered growth of dendrites, and inhibits the hydrogen evolution reaction commonly seen at low current density. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the formation mechanism of the single crystal zinc negative electrode of the present invention;

[0024] Figure 2 This is a scanning electron microscope image of the single crystal zinc negative electrode of Example 1 of the present invention;

[0025] Figure 3 This is a transmission electron microscope image of the single crystal zinc negative electrode of Example 1 of the present invention;

[0026] Figure 4This is a contact angle test diagram of the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0027] Figure 5 This is the zinc negative electrode charge and discharge efficiency test of each embodiment of the present invention (discharge depth is 30%);

[0028] Figure 6 This is the zinc negative electrode charge and discharge efficiency test of each embodiment of the present invention (discharge depth is 50%);

[0029] Figure 7 is a Tafel test curve diagram of the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0030] Figure 8 This is a graph showing the overpotential test of the hydrogen evolution reaction of the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0031] Fig. 9 This is a test diagram of the nucleation potential of a zinc-copper half-cell assembled by the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0032] Fig.10 This is a test diagram of the deposition potential of a zinc-copper half-cell assembled by the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0033] Fig.11 This is a coulombic efficiency test diagram of a zinc-copper half-cell assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0034] Fig.12 This is a coulombic efficiency test diagram of a zinc-zinc symmetric battery assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1;

[0035] Fig.13 This is a capacity test diagram of a zinc-manganese dioxide battery assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1. DETAILED DESCRIPTION

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments and accompanying drawings specifically describe a single crystal zinc negative electrode, a preparation method and its application in assembling a high-performance zinc battery of the present invention.

[0038] Example 1

[0039] A method for preparing a single crystal zinc negative electrode in this embodiment includes the following steps:

[0040] Step S1, cutting the brass foil into 3×3 cm, the brass foil thickness is 0.05 μm, cleaning and drying, and obtaining a brass foil substrate without any contaminants on the surface;

[0041] Step S2, placing a brass foil substrate in the central area of ​​the tube furnace, preparing reactants 8 mg of copper acetylacetonate and 2 mg of chloranil, placing the copper acetylacetonate in the upstream part of the tube furnace, and placing the chloranil in the downstream part to ensure that the reactants are evenly distributed;

[0042] Step S3, introducing argon gas into the tube furnace at a flow rate of 3 L / min, gradually increasing the furnace temperature to 300° C., and maintaining the temperature for 2 hours to drive the deposition reaction of the Cu3(C6O6)2 film. After the reaction is completed, gradually cooling to room temperature, and taking out the brass foil substrate on which the Cu3(C6O6)2 film has been synthesized;

[0043] Step S4: The brass foil substrate on which the Cu3(C6O6)2 film has been synthesized is assembled in a button cell as the working electrode. A zinc layer is deposited on the surface of the Cu3(C6O6)2 film by electrodeposition. A 2M zinc sulfate electrolyte is added, and the negative electrode is a commercial zinc foil. The electroplating procedure is set, and the current density is 0.1 mA cm -2 The electroplating time was 100 h. After the procedure was completed, the battery was disassembled, the electroplated brass foil substrate was taken out, and it was cleaned with deionized water to obtain a single crystal zinc negative electrode with a single (0002) crystal plane exposure.

[0044] The single crystal zinc negative electrode obtained above is used to assemble a high-performance zinc battery, and the application method is as follows:

[0045] Provided is an aqueous zinc-manganese dioxide full battery, wherein the electrolyte of the battery is a 2M zinc sulfate electrolyte, the negative electrode is single crystal zinc prepared by the above preparation method, the positive electrode is a MnO2 material, and the battery is assembled using a GE-Whatman glass fiber separator.

[0046] Among them, the preparation method of the positive electrode of the battery is as follows: 8 mg of sodium hypophosphite and 10 mg of potassium permanganate are respectively dissolved in 20 mL of deionized water, and the potassium permanganate solution is slowly added to the sodium hypophosphite solution through a constant pressure titration funnel under stirring for 0.5 h, and the precipitate is collected after centrifugation, washed with water to remove residual salt, and then dried in a freeze dryer for 24 hours. 60wt% of polytetrafluoroethylene emulsion (purchased from Shanghai San Ai Fu New Materials Co., Ltd.) and graphite are added to the above-mentioned manganese dioxide material, and the mass is controlled to be manganese dioxide material: 60wt% of polytetrafluoroethylene emulsion: graphite = 8:1:1. After mixing evenly, it is placed in an oven for drying, and the dried sample is pressed on a stainless steel mesh (purchased from Ningcong Silk Screen in Jiangsu Province) at a pressure of 20MPa, and vacuum dried at 60°C for 24 hours to obtain the positive electrode of the battery.

[0047] The energy storage performance of the aqueous zinc-manganese dioxide full battery was tested using the CHI660E electrochemical workstation and the blue electric test device. The capacity retention rate of the aqueous zinc-manganese dioxide full battery after 1,500 cycles of charge and discharge was above 76%, demonstrating excellent energy density and outstanding cycle life.

[0048] Figure 1 It is a schematic diagram of the formation mechanism of the single crystal zinc negative electrode of the present invention.

[0049] like Figure 1 As shown, through the synergistic effect of the brass substrate and the Cu3(C6O6)2 film, efficient desolvation of zinc ions and a low lattice mismatch of 4.24% were achieved, thereby promoting the directional nucleation and epitaxial growth of Zn. This design helps to improve the stability and uniformity of the zinc layer and optimize battery performance.

[0050] Figure 2 This is a scanning electron microscope image of the single crystal zinc negative electrode of Example 1 of the present invention.

[0051] like Figure 2 As shown, the dense negative electrode texture exhibits stable epitaxial growth, which is beneficial to the long-cycle performance of zinc batteries.

[0052] Figure 3 This is a transmission electron microscope image of the single crystal zinc negative electrode of Example 1 of the present invention.

[0053] like Figure 3 As shown in the figure, the exposed crystal plane can be determined based on the growth direction of the negative electrode zinc layer and the orientation of the epitaxial growth layer. Since zinc metal is a hexagonal crystal system, It is perpendicular to the (0002) crystal plane, so it can be concluded that the exposed crystal plane of the prepared negative electrode is the (0002) plane.

[0054] Example 2

[0055] In this example, based on the preparation conditions of Example 1, the masses of copper (II) acetylacetonate and chloranil added in step S2 were replaced with 4 mg and 2 mg, respectively.

[0056] The test shows that the zinc negative electrode prepared under this condition has a higher surface flatness, but its (0002) crystal plane exposure is slightly reduced, resulting in a slight decrease in its specific capacity compared with Example 1, and the operating discharge depth can only reach 50%.

[0057] Example 3

[0058] In this example, based on the preparation conditions of Example 1, the masses of copper (II) acetylacetonate and chloranil added in step S2 were replaced with 6 mg and 2 mg, respectively.

[0059] Example 4

[0060] In this embodiment, based on the preparation conditions of Example 1, the furnace temperature in step S3 is set to 400° C. and maintained for 2 hours.

[0061] Example 5

[0062] In this embodiment, based on the preparation conditions of Example 1, the furnace temperature in step S3 is set to 500°C.

[0063] Figure 5 This is a test of the zinc negative electrode charge and discharge efficiency of each embodiment of the present invention (discharge depth is 30%).

[0064] The higher the efficiency value, the better the reversibility of the negative electrode. Example 1 shows a higher coulombic efficiency than the other examples, reaching 99%, indicating that the zinc negative electrode of Example 1 has higher reversibility and more stable cycle performance.

[0065] Figure 6 This is a test of the zinc negative electrode charge and discharge efficiency of each embodiment of the present invention (discharge depth is 50%).

[0066] The higher the efficiency value, the better the reversibility of the negative electrode. Figure 6 As shown, Example 1 exhibits a higher coulombic efficiency than the other examples, reaching 99%, indicating that the zinc negative electrode of Example 1 has higher reversibility and more stable cycle performance.

[0067] Comparative Example 1

[0068] In this comparative example, based on the preparation conditions of Example 1, a commercial zinc sheet was selected as the negative electrode material.

[0069] Figure 4 This is a contact angle test diagram of the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0070] like Figure 4 As shown, Example 1 exhibits a smaller contact angle than Comparative Example 1. A smaller contact angle indicates that the material has a stronger hydrophilicity, which is beneficial to the uniform distribution of the electrolyte and ion conduction, thereby improving the overall performance of the battery. This test result provides an important reference for selecting the optimal negative electrode material.

[0071] Figure 7 It is a Tafel test curve diagram of the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0072] like Figure 7 As shown, the present invention conducted Tafel polarization tests on commercial zinc sheets and single crystal zinc sheets. The test results show that the corrosion current density of the single crystal zinc sheet is 3.04 mA cm-2, which is significantly lower than the 6.22 mA cm-2 of the commercial zinc sheet. This indicates that the single crystal zinc sheet has a lower corrosion rate and is more conducive to long-term stable operation in an aqueous electrolyte.

[0073] Figure 8 This is a test diagram of the overpotential of the hydrogen evolution reaction of the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0074] like Figure 8 As shown in the figure, the hydrogen evolution overpotential of the single crystal zinc sheet is 341.18 mA dec-1, which is significantly higher than the 232.30 mA dec-1 of the commercial zinc sheet. This indicates that the single crystal zinc sheet has a slower hydrogen evolution rate and is more conducive to long-term stable operation in aqueous electrolytes.

[0075] Fig. 9 This is a test diagram of the nucleation potential of a zinc-copper half-cell assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0076] like Fig. 9 As shown, the potential test diagram uses voltage as the vertical axis and electroplating capacity as the horizontal axis. The smaller the deposition voltage, the lower the nucleation overpotential of the negative electrode, which is more conducive to the stable nucleation of zinc ions and the epitaxial growth of the zinc layer.

[0077] Fig.10 This is a deposition potential test diagram of a zinc-copper half-cell assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0078] like Fig.10 As shown, the potential test diagram uses voltage as the vertical axis and time as the horizontal axis. The smaller the cycle voltage, the stronger the stability of the negative electrode. The final stripping capacity is used to measure the reversible efficiency of the negative electrode. The closer to 120h, the better the reversibility of the corresponding zinc negative electrode.

[0079] Fig.11This is a coulombic efficiency test chart of a zinc-copper half-cell assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0080] like Fig.11 As shown, the potential test graph uses Coulomb efficiency as the vertical axis and the number of cycles as the horizontal axis. The higher the cycle efficiency, the better the reversibility of the negative electrode. The more cycles, the better the long-cycle performance of the negative electrode, which is more conducive to long-term stable operation in aqueous electrolytes.

[0081] Fig.12 This is a coulombic efficiency test chart of a zinc-zinc symmetric battery assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0082] like Fig.12 As shown, the potential test graph uses voltage as the vertical axis and time as the horizontal axis. The smaller the cycle voltage, the stronger the stability of the negative electrode and the longer the cycle time, which proves that the long-cycle performance of the negative electrode is better and it is more conducive to long-term stable operation in aqueous electrolytes.

[0083] Fig.13 This is a capacity test diagram of a zinc-manganese dioxide battery assembled with the single crystal zinc negative electrode of Example 1 of the present invention and the commercial zinc sheet of Comparative Example 1.

[0084] like Fig.13 As shown, the cycle performance test graph uses specific capacity as the vertical axis and the number of cycles as the horizontal axis. The larger the specific capacity value and the more cycles, the better the battery performance. By comparison, the performance of the Zn-MnO2 full battery assembled in Example 1 is significantly better than that in Comparative Example 1, and the capacity retention rate of the assembled Zn-MnO2 full battery after 1500 cycles of charge and discharge is above 76%, and it has a longer cycle life.

[0085] Functions and Effects of the Embodiments

[0086] According to the single crystal zinc negative electrode, preparation method and application in aqueous zinc battery involved in the present invention, the metal organic framework material Cu3(C6O6)2 is deposited on the brass substrate by vapor deposition, and the low lattice mismatch between the brass substrate and the deposited zinc layer is utilized to effectively promote the zinc atoms in the electroplated zinc layer to be arranged in order along the (0002) crystal plane, significantly improving the uniformity of the zinc negative electrode surface, reducing the orientation difference and lattice distortion between different crystal planes. The preferential exposure of this single crystal plane reduces the surface energy of the zinc negative electrode, helps to achieve a stable zinc ion deposition / stripping process, and prolongs the service life of the battery.

[0087] The ordered porous Cu3(C6O6)2 film of the present invention provides a fast transmission channel for zinc ions and reduces the overpotential of zinc ions during the deposition process. This design effectively reduces the nucleation barrier of zinc ions, prevents the disordered growth of dendrites, and inhibits the hydrogen evolution reaction commonly seen at low current density.

[0088] The raw materials in the present invention are widely available, low in cost and environmentally friendly; the preparation process of the zinc battery electrolyte and the aqueous zinc battery is simple and easy to operate, and does not involve toxic and harmful reagents or vacuum preparation conditions.

[0089] The single crystal zinc negative electrode of the present invention shows excellent performance in different battery assemblies. For example, the zinc||zinc battery using the single crystal zinc negative electrode of the present invention has a high performance at 1 mA cm -2 、1mAh cm -2 Under the condition of 10 mA cm -2 Under the above conditions, the average coulombic efficiency is as high as 99.55%, and the excellent performance can be maintained after 4000 cycles. The zinc||manganese dioxide soft pack battery (1.47Ah) using the zinc negative electrode of the present invention can maintain good stability after 500 cycles at a current of 1A / g.

[0090] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a single crystal zinc negative electrode, characterized in that: The following steps are involved: Step S1, cutting, cleaning and drying the brass foil to obtain a brass foil substrate; Step S2, placing the brass foil substrate in the central area of ​​the tube furnace, preparing reactants copper acetylacetonate and chloranil, placing the copper acetylacetonate in the upstream part of the tube furnace, and placing the chloranil in the downstream part to ensure that the reactants are evenly distributed; Step S3, introducing an inert gas into the tube furnace, gradually raising the furnace temperature to 300-500°C, and maintaining the temperature for 1.5-2.5 hours to drive the deposition reaction of the Cu3(C6O6)2 film. After the reaction is completed, gradually cooling to room temperature, and taking out the brass foil substrate on which the Cu3(C6O6)2 film has been synthesized; Step S4: Assemble the brass foil substrate on which the Cu3(C6O6)2 film has been synthesized in a button cell as a working electrode, and deposit a zinc layer on the surface of the Cu3(C6O6)2 film by electrodeposition to obtain a single crystal zinc negative electrode with a single crystal plane exposure.

2. The method for preparing a single crystal zinc negative electrode according to claim 1, characterized in that: in, The furnace temperature in step S3 is 300°C.

3. The method for preparing a single crystal zinc negative electrode according to claim 2, characterized in that: in, The time for maintaining the furnace temperature in step S3 is 2 hours.

4. The method for preparing a single crystal zinc negative electrode according to claim 3, characterized in that: in, The mass ratio of copper acetylacetonate to chloranil is 1:(0.2-0.3).

5. The method for preparing a single crystal zinc negative electrode according to claim 1, characterized in that: The rare gas introduced into the tube furnace is argon, and the argon flow rate is set to 2-5 L / min to ensure that the atmosphere in the reaction zone is pure and oxygen-free.

6. A single crystal zinc negative electrode according to claim 1, characterized in that: The single crystal zinc negative electrode is prepared by the preparation method of any one of claims 1 to 5.

7. A single crystal zinc negative electrode according to claim 6, characterized in that: The single crystal zinc negative electrode comprises a brass foil substrate, a Cu3(C6O6)2 film synthesized on the brass foil substrate, and a zinc layer deposited on the surface of the Cu3(C6O6)2 film by an electro-deposition method.

8. Use of the single crystal zinc negative electrode as claimed in claim 6 or 7 in assembling a high performance zinc battery.

9. The use of the single crystal zinc negative electrode according to claim 8 in assembling a high performance zinc battery, characterized in that: in, The zinc battery for assembly includes a zinc-copper half-cell, a zinc symmetrical cell and a zinc-manganese dioxide full cell. When the battery for assembly is a zinc symmetrical cell, 1 mA cm -2 、1mAh cm -2 When the battery used for assembly is a zinc-copper half-cell, 10 mA cm -2 When the battery used for assembly is a zinc manganese dioxide full battery, the current conditions of 1.47Ah and 1A / g are selected.

10. The use of the single crystal zinc negative electrode according to claim 9 in assembling a high performance zinc battery, characterized in that: in, The single crystal zinc negative electrode is used as the negative electrode material of the zinc metal battery, and the electrolyte is a zinc sulfate aqueous electrolyte. During the battery cycle, the zinc ions in the zinc salt are regulated by the single crystal zinc negative electrode to form a dense zinc deposit on the brass substrate.

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