A zinc battery negative electrode with a layered double hydroxide surface modification and a preparation method thereof

Abstract

The present invention relates to a layered double hydroxide surface-modified zinc battery negative electrode and a preparation method thereof. After the polished zinc sheet is subjected to electrochemical activation pretreatment, constant voltage electrochemical stripping is carried out using a DC power supply. After completion, ultrasonic cleaning is performed. A solution containing two nitrates is weighed and prepared, and a three-electrode system is constructed. Subsequently, a DC power supply is used to perform constant current electrochemical deposition with the zinc sheet as the working electrode. After drying, a zinc sheet with a layered double hydroxide thin film attached to the surface is obtained, which is the layered double hydroxide thin film surface-modified zinc battery negative electrode. Finally, an aqueous zinc ion battery is assembled. Compared with the prior art, the preparation method of the present invention has the characteristics of strong operability, low production cost, safety and high efficiency, environmental friendliness, etc. A layered double metal hydroxide interface modification layer is successfully constructed on the zinc battery negative electrode, solving the dendrite problem and water-induced side reactions of the zinc battery negative electrode, and is expected to be used in industrial production, providing new ideas for optimizing commercial zinc battery negative electrodes.

Description

Technical Field

[0001] The present invention relates to the technical field of battery materials, and in particular to a layered double hydroxide surface-modified zinc battery negative electrode and a preparation method thereof. Background Art

[0002] With the increasing consumption of traditional fossil fuels such as coal and petroleum, the energy and environmental crises have forced people to shift their attention to renewable clean energy. However, renewable energy has problems such as intermittency and low utilization rate. How to improve the input / output stability of such energy and its intelligent grid connection, rechargeable batteries play an important role in their storage and conversion processes. Currently, lithium-ion batteries have been dominant in the application market of secondary batteries due to their high energy density and high output voltage. However, lithium-ion batteries face various problems: the safety hazards brought by the inherently flammable organic electrolyte, the shortage of lithium supply due to the insufficient lithium resource reserves, and the high prices of transition metals and organic electrolytes, etc., all of which limit their long-term use in the field of large-scale energy storage. Therefore, seeking to develop new large-scale energy storage technologies with a safer system and lower preparation cost is the key.

[0003] So far, a variety of rechargeable aqueous metal ion (such as K + , Na + , Al 3+ , Zn 2+ ) batteries have been developed and may become the main energy system in the future. Among them, aqueous zinc ion batteries (ZIBs) have attracted much attention due to their inherent advantages: the high theoretical volume specific capacity (5855 mAh / cm 3 ) and mass specific capacity (820 mAh / g) of zinc metal, the lower oxidation / reduction potential (-0.76 V vs. standard hydrogen electrode), rich resources, and the non-toxicity, simple preparation process, high ionic conductivity, and low cost of aqueous zinc salt electrolytes.

[0004] The negative electrode material of the zinc ion battery uses metallic zinc. Due to the uneven distribution of ions and electric fields on the surface of the zinc ion battery negative electrode and the direct contact between zinc metal and the electrolyte, zinc dendrites and corrosion by-products are inevitably formed on the zinc sheet during the charge and discharge process of the battery cycle, resulting in a lower Coulomb efficiency and a limited cycle life, which is the most important part restricting the development of aqueous zinc ion batteries. Currently, interfacial modification of the negative electrode is one of the most effective solutions.

[0005] Layered double hydroxide (LDH) has attracted extensive attention due to its unique properties. The general formula of LDH can be expressed as where x = M 2+ / (M 2+ +M 3+ ), M 2+ and M3+ represents divalent and trivalent cations, A n- is an interlayer anion (such as carbonate ion, nitrate ion). Therefore, layered double hydroxides increase the possibility of various anion and cation combinations and achieve relatively uniform dispersion, thus having multifunctionality. The interface modification layer of layered double metal hydroxides has abundant metal sites to induce uniform nucleation of zinc; its excellent hydrophilic property can significantly reduce the interface resistance and promote the zinc ion transport kinetics; in addition, this modification layer has good chemical stability and significantly inhibits side reactions such as interface corrosion and hydrogen evolution as a physical barrier.

[0006] Generally, layered double hydroxides are mainly prepared by two methods: hydrothermal deposition and in-situ growth. In the former technique, LDH is mainly synthesized by the hydrothermal growth method and then further deposited on the metal substrate by different methods, but this method takes up to more than ten hours of preparation time and often has poor adhesion. In the latter technique, the LDH film grows directly on the substrate, showing better adhesion performance, but the operation is not simple, and at the same time, a high-temperature and high-pressure preparation environment is required, which significantly reduces the possibility of industrial application. Therefore, further exploration is still needed to develop the zinc sheet interface modification layer material and provide a new preparation process. Summary of the Invention

[0007] The purpose of the present invention is to overcome the defects of poor adhesion, long preparation time, low stability, and complex operation existing in the above two methods of hydrothermal deposition and in-situ growth, and to provide a layered double hydroxide surface-modified zinc battery negative electrode and its preparation method. The present invention electrochemically strips the zinc sheet in the form of anodic oxidation, increasing the binding force between the zinc sheet and the layered double hydroxide film, so that the layered double hydroxide film can be stably and uniformly attached to the surface of the zinc sheet.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] One of the technical solutions of the present invention is to provide a preparation method of a layered double hydroxide surface-modified zinc battery negative electrode, including the following steps:

[0010] S1. Pretreatment: Grind, ultrasonically clean, and dry the zinc sheet;

[0011] S2. Using the zinc sheet pretreated in step S1 as the anode, a copper sheet as the cathode, providing a constant voltage with a DC power supply, and placing it in a conductive salt solution for electrochemical stripping, and ultrasonically clean and dry the stripped zinc sheet;

[0012] S3. Weigh two nitrates and prepare them into a nitrate solution;

[0013] S4. Construct a three - electrode system. Use the zinc sheet dried in step S2 as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Use a DC power supply to provide a constant current density for the zinc sheet and conduct electrochemical deposition in the nitrate solution in step S3. Dry the zinc sheet after electrochemical deposition to obtain a zinc sheet surface - modified with a layered double - hydroxide film, which is the negative electrode of the zinc battery surface - modified with a layered double - hydroxide.

[0014] Further, in step S1, the zinc sheet is selected from pure zinc or zinc alloy.

[0015] Furthermore, the thickness of the zinc sheet is 20 - 200 μm, and the zinc content in the zinc alloy is greater than 80%.

[0016] More preferably, the zinc alloy includes but is not limited to Zn - Cu, Zn - Cu - Ti, Zn - Al, Zn - Sn.

[0017] Further, in step S1, grind the zinc sheet until there are no obvious scratches on the surface. Place the ground zinc sheet in ethanol, acetone, and deionized water in sequence for ultrasonic cleaning. The ultrasonic cleaning time is 10 - 30 min respectively, and the drying temperature is 60 - 90 °C.

[0018] Further, in step S2, the constant voltage is - 0.8 - - 1.7 V; the time for electrochemical stripping is 5 - 40 min.

[0019] Further, in step S2, the conductive salt solution is selected from any one of sodium sulfate solution, potassium sulfate solution, magnesium sulfate solution, aluminum sulfate solution, sodium chloride solution, potassium chloride solution, magnesium chloride solution, aluminum chloride solution, or iron chloride solution, and the concentration of the conductive salt solution is 0.1 - 1.0 mol / L.

[0020] Further, in step S2, place the stripped zinc sheet in ethanol and deionized water in sequence for ultrasonic cleaning. The ultrasonic cleaning time is 10 - 30 min respectively, and the drying temperature is 60 - 90 °C.

[0021] Further, in step S3, the nitrate is selected from any two of zinc nitrate, aluminum nitrate, nickel nitrate, cobalt nitrate, magnesium nitrate, iron nitrate, or manganese nitrate. The mass ratio of the two nitrates is 1:5 - 5:1, and the total concentration of the two nitrates is 100 - 200 mmol / L.

[0022] Further, in step S4, the constant current density is 0.5 - 5.0 mA / cm 2 ; the electrochemical deposition time is 2 - 150 min; the drying method is selected from any one of natural air - drying, air - blowing, freeze - drying, or low - temperature drying.

[0023] The second technical solution of the present invention is to provide a negative electrode of a layered double hydroxide surface-modified zinc battery, based on the preparation method of the negative electrode of the layered double hydroxide surface-modified zinc battery described in the first technical solution.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) In the present invention, electrochemical stripping of zinc flakes is carried out by anodic oxidation to improve the interfacial electric field and ion distribution, greatly increasing the binding force between the zinc flakes and the layered double hydroxide film, so that the film can be stably and uniformly attached to the surface of the zinc flakes.

[0026] (2) Through the technology of the present invention, interfacial modification layers of different types and atomic ratios of layered double metal hydroxides can be prepared, providing a buffer space for the formation of zinc dendrites, improving the wettability and stability of the negative electrode of the zinc battery, providing continuous and abundant short-distance channels for charge transport, and also providing abundant reaction sites for electrochemical reactions, showing high capacitance behavior, so that the zinc battery material has excellent cycle stability and energy density.

[0027] (3) The present invention realizes the preparation of a fast and controllable negative electrode modification layer of a zinc battery, that is, the preparation of a layered double metal hydroxide film, and regulates the microscopic morphology and uniform deposition of the double metal hydroxide film layer by adjusting the current density and time.

[0028] (4) The preparation method of the present invention has the characteristics of strong operability, low production cost, safety, high efficiency, environmental friendliness, etc. It successfully constructs a layered double metal hydroxide interfacial modification layer on the negative electrode of the zinc battery, solves the dendrite problem and water-induced side reactions of the negative electrode of the zinc battery, and is expected to be applied to industrial production, providing a new idea for the optimization of commercial negative electrodes of zinc batteries. Description of the Drawings

[0029] Figure 1 It is a scanning electron microscope (SEM) image of the negative electrode of the layered double hydroxide surface-modified zinc battery prepared in Example 1;

[0030] Figure 2 It is a digital photo, SEM image and corresponding element distribution map of the negative electrode of the layered double hydroxide surface-modified zinc battery prepared in Examples 1-2;

[0031] Figure 3 It is the long cycle performance of the battery composed of the negative electrode of the layered double hydroxide surface-modified zinc battery prepared in Examples 1-2 at a current of 1 mA / cm 2 and 1 mAh / cm 2 ;

[0032] Figure 4XRD patterns of the zinc battery negative electrodes with layered double hydroxide surface modification prepared in Examples 1-2.

[0033] Figure 5 The batteries composed of the zinc battery negative electrodes with layered double hydroxide surface modification prepared in Example 1 and Comparative Example 1 at a current density of 1 mA / cm 2 and 1 mAh / cm 2 and their digital photos.

[0034] Among them, Figure 3 and 4 ZnAl-LDH@Zn represents the zinc battery negative electrode with a ZnAl-LDH layer electro-deposited on the surface (prepared in Example 1), and NiCo-LDH@Zn represents the zinc battery negative electrode with a NiCo-LDH layer electro-deposited on the surface (prepared in Example 2). Detailed Description of the Invention

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific examples.

[0036] In the following examples and comparative examples, unless otherwise specified, the raw materials or processing techniques are all conventional commercially available raw material products or conventional processing techniques in the art.

[0037] Example 1:

[0038] A method for preparing a zinc battery negative electrode with layered double hydroxide surface modification includes the following steps: Cut a commercially purchased pure zinc sheet into small pieces of 3×3.5 cm, and polish it with 3000-mesh sandpaper until there are no obvious scratches on the surface. Electrochemically activate and pre-treat the polished zinc sheet, ultrasonically clean it in ethanol, acetone, and deionized water for 10 min each in sequence, and dry it in an oven at 60°C. Then, use a DC power supply to provide a constant voltage of -1.0 V, use the zinc sheet as the anode and a copper sheet as the cathode, and place them in a 0.5 mol / L sodium sulfate solution for electrochemical stripping for 20 min. Then, ultrasonically clean the stripped zinc sheet in ethanol and deionized water for 10 min each in sequence, and dry it in an oven at 60°C. Weigh zinc nitrate and aluminum nitrate with a mass ratio of 1:1 and prepare a nitrate solution with a total concentration of 150 mmol / L. Construct a three-electrode system, use the cleaned zinc sheet as the working electrode, a platinum electrode as the counter electrode, and a saturated calomel electrode as the reference electrode. Then, use a DC power supply to provide a constant current density of 1.0 mA / cm 2 for the zinc sheet, electrochemically deposit it in the nitrate solution for 5 min, and air-dry it for 12 h to obtain a zinc sheet with a ZnAl-LDH layer attached to the surface, which is the zinc battery negative electrode with ZnAl-LDH layer surface modification and is used to assemble an aqueous zinc ion battery.

[0039] Example 2:

[0040] A preparation method for a zinc battery negative electrode modified with layered double hydroxide on the surface, comprising the following steps: Cut a commercially purchased pure zinc sheet into small pieces of 4×5 cm, and polish it with 3000-mesh sandpaper until there are no obvious scratches on the surface. Perform electrochemical activation pretreatment on the polished zinc sheet, ultrasonically clean it in ethanol, acetone, and deionized water for 20 min each in sequence, and dry it in an oven at 90 °C. Then, use a DC power supply to provide a constant voltage of -1.0 V, use the zinc sheet as the anode and a copper sheet as the cathode, and place them in a 1.0 mol / L potassium sulfate solution for electrochemical stripping for 20 min. Then, ultrasonically clean the stripped zinc sheet in ethanol and deionized water for 20 min each in sequence, and dry it in an oven at 90 °C. Weigh cobalt nitrate and nickel nitrate with a mass ratio of 1:1, and prepare a nitrate solution with a total concentration of 150 mmol / L. Construct a three-electrode system, use the cleaned zinc sheet as the working electrode, platinum as the counter electrode, and a saturated calomel electrode as the reference electrode. Then, use a DC power supply to provide a constant current density of 1.0 mA / cm 2 to the zinc sheet, electrochemically deposit it in the nitrate solution for 10 min, and air-dry it for 10 h to obtain a zinc sheet with an NiCo-LDH layer attached to the surface, which is the zinc battery negative electrode modified with the NiCo-LDH layer on the surface and is used to assemble an aqueous zinc-ion battery.

[0041] Example 3:

[0042] A preparation method for a zinc battery negative electrode modified with layered double hydroxide on the surface, comprising the following steps: Cut a commercially purchased pure zinc sheet into small pieces of 3×4 cm, and polish it with 3000-mesh sandpaper until there are no obvious scratches on the surface. Perform electrochemical activation pretreatment on the polished zinc sheet, ultrasonically clean it in ethanol, acetone, and deionized water for 10 min each in sequence, and dry it in an oven at 75 °C. Then, use a DC power supply to provide a constant voltage of -0.8 V, use the zinc sheet as the anode and a copper sheet as the cathode, and place them in a 0.1 mol / L sodium chloride solution for electrochemical stripping for 40 min. Then, ultrasonically clean the stripped zinc sheet in ethanol and deionized water for 30 min each in sequence, and dry it in an oven at 75 °C. Weigh aluminum nitrate and nickel nitrate with a mass ratio of 5:1, and prepare a nitrate solution with a total concentration of 100 mmol / L. Construct a three-electrode system, use the cleaned zinc sheet as the working electrode, platinum as the counter electrode, and a saturated calomel electrode as the reference electrode. Then, use a DC power supply to provide a constant current density of 0.5 mA / cm 2 to the zinc sheet, electrochemically deposit it in the nitrate solution for 150 min, and freeze-dry it for 20 h to obtain a zinc sheet with an AlNi-LDH layer attached to the surface, which is the zinc battery negative electrode modified with the AlNi-LDH layer on the surface and is used to assemble an aqueous zinc-ion battery.

[0043] Example 4:

[0044] A preparation method for a cathode of a zinc battery with a layered double hydroxide surface modification, comprising the following steps: Cut commercially purchased zinc alloy Zn95Cu5 into small pieces of 5×6 cm, and polish them with 3000-mesh sandpaper until there are no obvious scratches on the surface. Electrochemically activate and pre-treat the polished zinc sheets, ultrasonically clean them in ethanol, acetone, and deionized water for 30 min each in sequence, and dry them in an oven at 60 °C. Then, use a DC power supply to provide a constant voltage of -1.7 V, use the zinc sheet as the anode and the copper sheet as the cathode, and place them in a 1.0 mol / L sodium sulfate solution for electrochemical stripping for 5 min. Then, ultrasonically clean the stripped zinc sheets in ethanol and deionized water for 10 min each in sequence, and dry them in an oven at 60 °C. Weigh cobalt nitrate and magnesium nitrate with a mass ratio of 1:5, prepare a nitrate solution with a total concentration of 200 mmol / L, construct a three-electrode system, use the cleaned zinc sheet as the working electrode, platinum as the counter electrode, and a saturated calomel electrode as the reference electrode. Then, use a DC power supply to provide a constant current density of 5.0 mA / cm 2 to the zinc sheet, electrochemically deposit in the nitrate solution for 2 min, and obtain a zinc sheet with a CoMg-LDH layer attached to the surface after low-temperature drying for 8 h, which is the cathode of the zinc battery with a CoMg-LDH layer surface modification and is used to assemble an aqueous zinc-ion battery.

[0045] Example 5:

[0046] Compared with Example 1, most of them are the same, except that the sodium sulfate solution is replaced with a magnesium sulfate solution, and zinc nitrate and aluminum nitrate are replaced with iron nitrate and manganese nitrate, and the rest remain the same.

[0047] Example 6:

[0048] Compared with Example 1, most of them are the same, except that the sodium sulfate solution is replaced with an aluminum sulfate solution, and the rest remain the same.

[0049] Example 7:

[0050] Compared with Example 1, most of them are the same, except that the sodium sulfate solution is replaced with a potassium chloride solution, and the rest remain the same.

[0051] Example 8:

[0052] Compared with Example 1, most of them are the same, except that the sodium sulfate solution is replaced with a magnesium chloride solution, and the rest remain the same.

[0053] Example 9:

[0054] Compared with Example 1, most of them are the same, except that the sodium sulfate solution is replaced with an aluminum chloride solution, and the rest remain the same.

[0055] Example 10:

[0056] Compared with Example 1, most of them are the same. Except that the sodium sulfate solution is replaced with a ferric chloride solution, the rest remain consistent.

[0057] Comparative Example 1:

[0058] Compared with Example 1, most of them are the same. Except that the electrochemically exfoliating step is omitted. The specific steps are as follows: Cut the commercially pure zinc sheet into small pieces of 3×3.5 cm, and polish it with 3000-mesh sandpaper until there are no obvious scratches on the surface. Place the polished zinc sheet in ethanol, acetone, and deionized water in turn and ultrasonically clean each for 10 min, and then dry it in an oven at 60 °C. Then weigh zinc nitrate and aluminum nitrate with a mass ratio of 1:1 and prepare a solution with a total concentration of 150 mmol / L. Construct a three-electrode system, use the cleaned zinc sheet as the working electrode, platinum as the counter electrode, and saturated calomel electrode as the reference electrode. Then use a DC power supply to provide a constant current density of 1.0 mA / cm 2 to the zinc sheet, electrochemically deposit for 5 min, and let it dry naturally for 12 h to obtain the negative electrode of the zinc battery with a layered double hydroxide film attached to the surface, which is used to assemble an aqueous zinc-ion battery.

[0059] Figure 1 Figure 12 is a scanning electron microscope (SEM) image of the negative electrode of the zinc battery surface-modified by the ZnAl-LDH layer of the layered double hydroxide film prepared in Example 1. The prepared ZnAl-LDH layer adheres uniformly on the zinc sheet substrate. The microscopic morphology of the material presents a nano-flower shape, and the surface structure is a three-dimensional sheet cross. It can not only increase the specific surface area but also increase the binding force between the ZnAl-LDH layer and the zinc sheet. This structure provides continuous, uniform, and abundant channels for charge transfer.

[0060] Figure 2 Figure 13 is a digital photo, SEM image, and corresponding element distribution map of the negative electrode of the zinc battery surface-modified by the layered double hydroxide film prepared in Examples 1-2 (a, c are the negative electrodes of the zinc battery surface-modified by the ZnAl-LDH layer prepared in Example 1, and b, d are the negative electrodes of the zinc battery surface-modified by the NiCo-LDH layer prepared in Example 2). On the surface of the pretreated zinc foil, the corresponding layered double hydroxide film coating is electrodeposited uniformly, showing good binding force with the substrate, which can significantly improve the charge distribution on the surface of the bare zinc under the action of the electric field and realize the uniform deposition / stripping of Zn 2+ .

[0061] The zinc battery anodes prepared in the above examples and comparative examples were assembled and tested for their electrochemical performance: The layered double hydroxide film surface-modified zinc battery anodes prepared in the above examples and comparative examples were taken. A pure zinc sheet (diameter 12 mm, purity ≥ 99.99%) was used as the positive electrode, 3 mol / L zinc sulfate solution was used as the electrolyte, and glass fiber was used as the separator. The battery was assembled in air. The assembled button battery was tested for its electrochemical performance, and the charge-discharge voltage range was 0.3 - 1.6 V (vs. Zn 2+ / Zn).

[0062] Figure 3 The long cycle performance of the zinc battery assembled with the layered double hydroxide film surface-modified zinc battery anode prepared in Examples 1 - 2 at 1 mA / cm 2 , 1 mAh / cm 2 current. By testing the cycle stability of the zinc battery anodes with ZnAl-LDH layer and NiCo-LDH layer attached, it can be seen that the cycle time of NiCo-LDH@Zn can reach about 400 h, and the cycle time of ZnAl-LDH@Zn can reach about 375 h, indicating that the zinc battery anodes with ZnAl-LDH layer and NiCo-LDH layer attached have good chemical stability and significant effects as physical barriers to inhibit side reactions such as interfacial corrosion and hydrogen evolution.

[0063] Figure 4 The XRD patterns of the layered double hydroxide film surface-modified zinc battery anodes prepared in Examples 1 - 2. Compared with the standard card, the characteristic crystal plane diffraction peaks of ZnAl-LDH@Zn and NiCo-LDH@Zn are (003), (006), and (012), and the intensities of the XRD diffraction peaks of ZnAl-LDH@Zn and NiCo-LDH@Zn become stronger, indicating that the crystallinity has increased, meeting the expected goal.

[0064] Figure 5 The long cycle performance and digital photos of the battery composed of the layered double hydroxide film surface-modified zinc battery anodes prepared in Example 1 and Comparative Example 1 at 1 mA / cm 2 , 1 mAh / cm 2 current. It can be seen from the digital photos that the green layered double hydroxide on the surface of the zinc battery anode (A) prepared in Example 1 is evenly distributed and completely covers the surface of the zinc sheet. The grayish-white layered double hydroxide on the surface of the zinc battery anode (B) obtained in Comparative Example 1 is extremely unevenly distributed, and the microscopic morphology of the zinc battery anode shows many un-deposited exposed parts. The modified layer is easy to fall off, and according to the long cycle performance test, the cycle life time of the assembled zinc battery is short. Therefore, electrochemical stripping can improve the bonding situation between the zinc sheet and the layered double hydroxide modified layer and improve the cycle performance of the zinc battery.

[0065] The above description of the embodiments is provided to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention according to the disclosure of the present invention.

Claims

1. A preparation method of a zinc battery negative electrode with a layered double hydroxide surface modification, characterized in that, It includes the following steps: S1. Pretreatment: Polish, ultrasonically clean, and dry the zinc sheet. S2. Using the zinc sheet pretreated in step S1 as the anode, a copper sheet as the cathode, providing a constant voltage with a DC power supply, and placing it in a conductive salt solution for electrochemical stripping. Ultrasonically clean and dry the stripped zinc sheet. S3. Weigh two nitrates and prepare a nitrate solution. S4. Construct a three - electrode system. Using the zinc sheet dried in step S2 as the working electrode, a platinum sheet as the counter electrode, and a saturated calomel electrode as the reference electrode. Use a DC power supply to provide a constant current density for the zinc sheet and perform electrochemical deposition in the nitrate solution in step S3. Dry the electrochemically deposited zinc sheet to obtain a zinc sheet surface - modified with a layered double - hydroxide film, which is the negative electrode of the layered double - hydroxide surface - modified zinc battery.

2. The preparation method of the layered double hydroxide surface modified zinc battery negative electrode according to claim 1, characterized in that, In step S1, the zinc sheet is selected from pure zinc or zinc alloy.

3. The preparation method of the layered double hydroxide surface-modified zinc battery negative electrode according to claim 2, characterized in that, The thickness of the zinc sheet is 20 - 200 μm, and the zinc content in the zinc alloy is greater than 80%.

4. The preparation method of the layered double hydroxide surface modified zinc battery negative electrode according to claim 1, characterized in that In step S1, polish the zinc sheet until there are no obvious scratches on the surface. Place the polished zinc sheet in ethanol, acetone, and deionized water in sequence for ultrasonic cleaning, and the ultrasonic cleaning time is 10 - 30 min respectively. The drying temperature is 60 - 90 °C.

5. The preparation method of the negative electrode of the layered double hydroxide surface-modified zinc battery according to claim 1, characterized in that, In step S2, the constant voltage is - 0.8 - - 1.7 V; the electrochemical stripping time is 5 - 40 min.

6. The preparation method of the layered double hydroxide surface-modified zinc battery negative electrode according to claim 1, characterized in that In step S2, the conductive salt solution is selected from any one of sodium sulfate solution, potassium sulfate solution, magnesium sulfate solution, aluminum sulfate solution, sodium chloride solution, potassium chloride solution, magnesium chloride solution, aluminum chloride solution, or iron chloride solution, and the concentration of the conductive salt solution is 0.1 - 1.0 mol / L.

7. The preparation method of the layered double hydroxide surface modified zinc battery negative electrode according to claim 1, characterized in that, In step S2, place the stripped zinc sheet in ethanol and deionized water in sequence for ultrasonic cleaning, and the ultrasonic cleaning time is 10 - 30 min respectively. The drying temperature is 60 - 90 °C.

8. The preparation method of the layered double hydroxide surface-modified zinc battery negative electrode according to claim 1, characterized in that, In step S3, the nitrates are selected from any two of zinc nitrate, aluminum nitrate, nickel nitrate, cobalt nitrate, magnesium nitrate, iron nitrate, or manganese nitrate. The mass ratio of the two nitrates is 1:5 - 5:1, and the total concentration of the two nitrates is 100 - 200 mmol / L.

9. The preparation method of the layered double hydroxide surface-modified zinc battery negative electrode according to claim 1, characterized in that, In step S4, the constant current density is 0.5 to 5.0 mA / cm 2 ; the electrodeposition time is 2 to 150 min; the drying is selected from any one of natural air drying, air drying, freeze drying or low-temperature drying.

10. A negative electrode of a zinc battery with a surface-modified layered double hydroxide, characterized in that, Based on the preparation method of the negative electrode of the layered double - hydroxide surface - modified zinc battery as described in any one of claims 1 - 9.

Images