Preparation method and application of inorganic / organic composite coating material of aqueous zinc ion battery

Abstract

The application discloses a preparation method and application of an inorganic / organic composite coating material of an aqueous zinc ion battery, and belongs to the technical field of ion batteries. The preparation method comprises the following steps: providing a zinc metal substrate, and pretreating the zinc metal substrate; configuring an indium ion solution, and placing the zinc metal substrate into the indium ion solution for reaction to obtain an indium layer, then taking out the zinc metal substrate after washing, and drying; configuring a PVDF (polyvinylidene fluoride) / NMP (N-methyl pyrrolidone) solution, and placing the zinc metal substrate with the prepared indium layer into the PVDF / NMP solution for reaction to obtain a PVDF layer, and obtaining a zinc negative electrode material applied to the aqueous zinc ion battery after drying. The application comprises the following steps: preparing an electrode material into an electrode sheet by using the electrode material obtained by the preparation method, and applying the electrode sheet to the aqueous zinc ion battery. The indium layer and the PVDF layer effectively improve the cycle life of the battery.

Description

Technical Field

[0001] This invention relates to the field of ion battery technology, and more specifically, to a method for preparing and applying an inorganic / organic composite coating material for aqueous zinc-ion batteries. Background Technology

[0002] Aqueous zinc-ion batteries use zinc metal as the negative electrode in ion-ion batteries. Zinc dendrite growth is a major challenge for zinc negative electrodes, closely related to a series of side reactions. Firstly, due to the uneven distribution of zinc ions on the electrode surface and the inhomogeneity of the electric field, zinc ions tend to preferentially deposit at certain locations. Over time, these deposited zinc ions gradually grow into dendrites. Secondly, components such as water and dissolved oxygen in the aqueous electrolyte react chemically with the zinc negative electrode, resulting in zinc corrosion side reactions and the formation of corrosion products such as zinc oxide and zinc hydroxide. These corrosion products hinder the transport of zinc ions, leading to even more uneven zinc ion deposition on the electrode surface and further exacerbating zinc dendrite growth. When the zinc dendrites grow to a certain extent, they may puncture the separator, causing an internal short circuit and posing a safety hazard. Summary of the Invention

[0003] To address the aforementioned problems in the existing technology, the present invention aims to provide a method for preparing and applying an inorganic / organic composite coating material for aqueous zinc-ion batteries.

[0004] To solve the above problems, the technical solution adopted by the present invention is as follows: This application provides a method for preparing an inorganic / organic composite coating material for aqueous zinc-ion batteries, characterized by comprising the following steps: A zinc metal matrix is ​​provided, and the zinc metal matrix is ​​pretreated; An indium ion solution is prepared, and a zinc metal substrate is placed in the indium ion solution to react and obtain an indium layer. Then, the substrate is removed, rinsed, and dried. A PVDF / NMP solution is prepared, and a zinc metal substrate with an indium layer is placed into the PVDF / NMP solution to react and obtain a PVDF layer. After drying, an inorganic / organic composite coating material for use in aqueous zinc-ion batteries is obtained.

[0005] In some embodiments, the preprocessing includes: Prepare a hydrochloric acid solution, immerse the zinc metal substrate in the hydrochloric acid solution and sonicate it, then remove the zinc metal substrate, rinse it with deionized water and ethanol, and dry it.

[0006] In some embodiments, the step of preparing the indium ion solution includes: Mix InN3O9, C6H5Na3O7·2H2O and deionized water in a certain proportion and then stir.

[0007] In some embodiments, the molar amounts of InN3O9 and C6H5Na3O7·2H2O are both 2.5 mmol, and the ratio is 1:1.

[0008] In some embodiments, the steps for preparing the PVDF / NMP solution include: Dissolve PVDF (polyvinylidene fluoride) powder in NMP (N-methylpyrrolidone) solution and stir.

[0009] In some embodiments, 33.3 mg of PVDF should be added to every 10 mL of NMP.

[0010] In some embodiments, the drying method is to dry the object in a vacuum environment.

[0011] Another aspect of this application provides an application of an inorganic / organic composite coating material for an aqueous zinc-ion battery, comprising: using the inorganic / organic composite coating material obtained according to the preparation method described above as an electrode material to form an electrode sheet, and applying it to an aqueous zinc-ion battery.

[0012] In some embodiments, the electrode sheet is the negative electrode sheet of an aqueous zinc-ion battery.

[0013] In some embodiments, the electrode sheet comprises: a zinc metal substrate; an indium layer formed on the zinc metal substrate by a displacement reaction; and a PVDF layer formed on the indium layer by an impregnation method.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This application constructs an indium layer and a PVDF layer on a zinc metal substrate (e.g., zinc sheet). This composite coating effectively improves the cycle life of the battery. Specifically, the good conductivity and zinc affinity of the indium layer help balance the interfacial electric field and reduce the nucleation overpotential of zinc, while the PVDF layer can improve the mechanical flexibility of the zinc anode, adapt to volume changes during cycling, and prevent the electrode structure from being damaged. At the same time, the hydrophobicity of the PVDF layer can also reduce the content of free water and mitigate interfacial side reactions, thereby contributing to the stable deposition / dissolution behavior of the zinc anode. Attached Figure Description

[0015] Figure 1 The image shows a SEM image of Zn@In-PVDF obtained in Example 1. Figure 2 The symmetrical button cells of Example 1 and Comparative Examples 1 to 3 were tested at a current density of 1 mA / cm². -2 And the deposition surface capacity is 1 mAh cm⁻¹ -2 Long cycle curve of the peeling / electroplation cycle; Figure 3 For Comparative Example 4, a symmetrical button cell was used at a current density of 1 mA / cm². -2 And the deposition surface capacity is 1 mAh cm⁻¹ -2 Long cycle curve of the peeling / electroplation cycle; Figure 4 EIS test images of the negative electrode materials prepared in Example 1 and Comparative Examples 1 to 4; Figure 5 The negative electrode materials prepared in Examples 1 and Comparative Examples 1 to 3 were used at current densities of 0.3–6 mA / cm². -2 The deposition surface capacity is 1 mAh / cm³. -2 The multiplier cycle diagram.

[0016] Figure 6 The negative electrode material prepared in Comparative Example 4 was tested at current densities of 0.3–6 mA / cm². -2 The deposition surface capacity is 1 mAh / cm³. -2 The multiplier cycle diagram.

[0017] Figure 7 The half-cells of Example 1 and Comparative Examples 1 to 4 were measured at 1 mA cm⁻¹. -2 1 mAh cm -2 The Coulomb efficiency diagram. Detailed Implementation

[0018] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0019] To address the impact of zinc dendrite growth on battery performance in aqueous zinc-ion batteries, one embodiment of this application provides a method for preparing an inorganic / organic composite coating material for aqueous zinc-ion batteries, comprising the following steps: providing a zinc metal substrate and pretreating the zinc metal substrate to remove the surface oxide layer and impurities; preparing an indium ion solution and immersing the zinc metal substrate in the indium ion solution to react and obtain an indium layer, then removing, rinsing, and drying; preparing a PVDF / NMP solution and immersing the zinc metal substrate with the obtained indium layer in the PVDF / NMP solution to react and obtain a PVDF layer, and drying to obtain an inorganic / organic composite coating material for use in aqueous zinc-ion batteries. This embodiment forms an indium (In) layer and a PVDF layer sequentially on a zinc metal substrate (e.g., a zinc sheet) through a substitution reaction and a wetting method, and this composite coating can effectively improve the electrochemical performance of the battery.

[0020] One embodiment of this application provides an application of the composite coating material, namely, using the composite coating material obtained by the above preparation method as an electrode material to form an electrode sheet, and applying it to an aqueous zinc-ion battery to overcome the problem of zinc dendrite growth on the zinc negative electrode affecting the electrochemical performance and safety performance of the battery in traditional aqueous zinc-ion batteries. The electrode sheet includes: a zinc metal substrate; an indium layer formed on the zinc metal substrate through a substitution reaction; and a PVDF layer formed on the indium layer through a wetting method. This electrode sheet can be the negative electrode sheet of an aqueous zinc-ion battery. This embodiment constructs a composite coating based on an indium layer and a PVDF layer on a zinc metal substrate (e.g., a zinc sheet). The good conductivity and zinc affinity of the indium layer help balance the interfacial electric field and reduce the nucleation overpotential of zinc, while the PVDF layer can improve the mechanical flexibility of the zinc-ion battery negative electrode, adapt to volume changes during cycling, and prevent the electrode structure from being damaged. Simultaneously, the hydrophobicity of PVDF can reduce the content of free water and mitigate interfacial side reactions, thereby achieving stable deposition / dissolution behavior of the zinc-ion battery negative electrode. Based on this composite coating, the cycle life of the battery is effectively improved.

[0021] The following describes in detail the steps for preparing an indium and PVDF composite coating on a zinc metal substrate to obtain the aforementioned inorganic / organic composite coating material (i.e., electrode material), and further describes the advantages of the electrode material with indium and PVDF composite coating prepared in the embodiments of this application by combining the comparative electrode materials prepared in each comparative example for battery assembly and battery performance testing and characterization.

[0022] Example 1 (1) Preparation of electrode materials Pretreatment. Prepare a 0.01 mol / L hydrochloric acid solution, then immerse the zinc foil (i.e., the zinc metal substrate) in the hydrochloric acid solution and sonicate for 3 minutes. Rinse the zinc foil three times with deionized water and ethanol to remove residual hydrochloric acid solution. After the above treatment, allow the zinc foil to air dry at room temperature, and then cut it into zinc sheets with a diameter of 12 mm for later use.

[0023] Prepare an indium ion solution. Weigh 0.75 g of InN3O9 and 0.735 g of C6H5Na3O7·2H2O, then measure 50 mL of deionized water. Mix the InN3O9, C6H5Na3O7·2H2O, and deionized water, and place the mixture on a magnetic stirrer at 600 rpm for 30 min. Note that InN3O9 can be replaced with InN3O9·xH2O (x is any value), and the weighing amounts should be adjusted as needed.

[0024] Preparation of the indium layer: A dried zinc sheet is placed in the indium ion solution and reacted for 10 minutes. After that, it is taken out and rinsed 2-3 times with deionized water and ethanol, respectively. Then, the rinsed zinc sheet is placed in a vacuum drying oven at 60°C and dried for 8 hours to obtain the indium layer on the surface of the zinc sheet.

[0025] Prepare the PVDF / NMP solution. Weigh 100 mg of PVDF powder and measure 30 mL of NMP solution. Then mix the PVDF and NMP solutions and stir until the mixture is clear.

[0026] A PVDF layer was prepared. A zinc sheet with an indium layer was immersed in a PVDF / NMP solution for 10 minutes. After immersion, the zinc sheet was dried in a vacuum drying oven at 60°C for 12 hours to obtain the inorganic / organic composite coating material for aqueous zinc-ion batteries. This composite coating, Zn@In-PVDF, is an organic / inorganic composite coating material with an indium layer and a PVDF layer, and can be used as an electrode material for aqueous zinc-ion batteries.

[0027] (2) Assemble the battery First, place a piece of Zn@In-PVDF electrode material prepared according to the above steps as the positive electrode sheet into the positive electrode shell, then place a glass fiber separator in it, and use a pipette to drop 200 μL of 2M ZnSO4 as the electrolyte. Then, place another piece of Zn@In-PVDF electrode material as the negative electrode sheet on top of the separator. After that, place the gasket and spring sheet in sequence, and finally close the negative electrode shell. Use a battery packaging machine to seal the battery to obtain a modified aqueous zinc-ion battery, namely a zinc negative electrode aqueous zinc-ion symmetric button cell, labeled as Zn@In-PVDF / / Zn@In-PVDF symmetric button cell.

[0028] The cut copper foil is placed into the positive electrode shell, followed by a glass fiber separator. 200 μL of 2M ZnSO4 is dropped into the separator as the electrolyte. The electrode material Zn@In-PVDF prepared according to the above steps is then placed on top of the separator as the negative electrode. After that, the gasket and spring are placed in sequence, and the negative electrode shell is attached. The battery is then packaged using a battery packaging machine to obtain a modified Cu / / Zn@In-PVDF half cell.

[0029] Comparative Example 1 (1) Preparation of electrode materials Pretreatment. First, prepare a 0.01 mol / L hydrochloric acid solution. Then, immerse the zinc foil (i.e., the zinc metal substrate) in the hydrochloric acid solution and sonicate for 3 minutes. Next, rinse the zinc foil repeatedly with deionized water and ethanol to remove any residual hydrochloric acid solution. After the above treatment, allow the zinc foil to air dry at room temperature. Then, cut the zinc foil into zinc sheets with a diameter of 12 mm for later use.

[0030] Prepare an indium ion solution. Measure 50 mL of deionized water, then weigh 0.75 g of InN3O9 and 0.735 g of C6H5Na3O7·2H2O, mix them with the deionized water, and place the mixture on a magnetic stirrer and stir continuously at 600 r / min for 30 min.

[0031] Indium layer preparation: A zinc sheet was placed in the indium ion solution and reacted for 10 min. After that, it was removed and rinsed with deionized water and ethanol, respectively. The rinsed zinc sheet was then placed in a vacuum drying oven at 60°C and dried for 8 h to obtain the control electrode material Zn@In.

[0032] (2) Assemble the battery Using the comparative electrode material Zn@In obtained in this comparative example, the battery was assembled according to the assembly steps of the battery in Example 1, that is, replacing the electrode material Zn@In-PVDF in Example 1 as the electrode sheet to assemble Zn@In / / Zn@In symmetrical button cell and Zn@In / / Cu half cell.

[0033] Comparative Example 2 (1) Preparation of electrode materials Pretreatment. A 0.01 mol / L hydrochloric acid solution was prepared, and the zinc foil was then immersed in the hydrochloric acid solution and sonicated for 3 min. The zinc foil was then repeatedly rinsed with deionized water and ethanol to remove any residual dilute hydrochloric acid. The treated zinc foil was then allowed to air dry at room temperature to obtain the control electrode material, Bare-Zn.

[0034] (2) Assemble the battery Using the comparative electrode material Bare-Zn obtained in this comparative example, batteries were assembled according to the assembly steps of the battery in Example 1, that is, replacing the electrode material Zn@In-PVDF in Example 1 as the electrode sheet to assemble Bare-Zn / / Bare-Zn symmetrical button cells and Bare-Zn / / Cu half cells.

[0035] Comparative Example 3 (1) Preparation of electrode materials Pretreatment. Prepare a 0.01 mol / L hydrochloric acid solution, then immerse the zinc foil in the hydrochloric acid solution and sonicate for 3 minutes. Rinse the zinc foil repeatedly with deionized water and ethanol to remove any residual hydrochloric acid solution. Allow the treated zinc foil to air dry at room temperature, then cut the dried zinc foil into 12 mm diameter zinc sheets for later use.

[0036] Prepare the PVDF / NMP solution. Weigh 100 mg of PVDF powder and mix it with 30 mL of NMP solution, then stir until clear.

[0037] PVDF layer preparation: A dried zinc sheet was immersed in a PVDF / NMP solution for 10 min. After immersion, the zinc sheet was removed and dried in a vacuum drying oven at 60°C for 12 h to obtain the control electrode material Zn@PVDF.

[0038] (2) Assemble the battery Using the comparative electrode material Zn@PVDF obtained in this comparative example, the battery was assembled according to the assembly steps of the battery in Example 1, that is, replacing the electrode material Zn@In-PVDF in Example 1 as the electrode sheet to assemble Zn@PVDF / / Zn@PVDF symmetrical button cell and Zn@PVDF / / Cu half cell.

[0039] Comparative Example 4 (1) Preparation of electrode materials Pretreatment. Prepare a 0.01 mol / L hydrochloric acid solution, then immerse the zinc foil in the hydrochloric acid solution and sonicate for 3 minutes. Rinse the zinc foil repeatedly with deionized water and ethanol to remove any residual hydrochloric acid solution. Allow the treated zinc foil to air dry at room temperature, then cut the dried zinc foil into 12 mm diameter zinc sheets for later use.

[0040] Prepare a mixed copper ion solution. Weigh 5.7512 g of ZnSO4·7H2O, 4.9938 g of CuSO4·5H2O, and 2.16 g of boric acid, mix them with 400 ml of deionized water, and place the mixture on a magnetic stirrer. Stir continuously at 600 r / min until the solution becomes clear. Preparation of the copper layer: A zinc sheet was placed in a mixed solution for a displacement reaction. After 10 minutes, the zinc sheet was removed and repeatedly rinsed with ethanol and deionized water. It was then dried in a 60°C oven for 6-8 hours to obtain a copper layer on the surface of the zinc sheet, thus obtaining the material Zn@Cu.

[0041] Prepare the PVDF / NMP solution. Weigh 100 mg of PVDF powder and measure 30 mL of NMP solution. Mix the PVDF powder and NMP solution together and stir until the mixture is clear.

[0042] Preparation of the PVDF layer: The zinc sheet with the copper layer was immersed in the PVDF / NMP solution for 10 min. After immersion, the zinc sheet was dried in a vacuum drying oven at 60°C for 12 h to obtain the comparative electrode material Zn@Cu-PVDF based on the copper coating and PVDF coating. The comparative electrode material of this comparative example is an organic / inorganic composite coating material.

[0043] (2) Assemble the battery Using the comparative electrode material Zn@Cu-PVDF obtained in this comparative example, the battery was assembled according to the assembly steps of the battery in Example 1, that is, replacing the electrode material Zn@In-PVDF in Example 1 as the electrode sheet to assemble Zn@Cu-PVDF / / Zn@Cu-PVDF symmetrical button cell and Zn@Cu-PVDF / / Cu half cell.

[0044] In the research and application of aqueous zinc-ion batteries, symmetrical button cells are commonly used to evaluate the stability, cycle life, and interfacial performance of zinc anodes. By monitoring indicators such as voltage fluctuations and polarization, the reversibility of zinc deposition / dissolution processes and side reactions can be analyzed. Half-cells are mainly used to study zinc deposition / dissolution behavior, coulombic efficiency, and the interaction between the electrode and electrolyte. SEM images can clearly show the microstructure of the electrode surface, such as whether it is smooth, whether there are cracks, pores, or roughness. For example, if dendrite growth exists on the zinc anode surface, SEM images can visually display the morphology, size, and distribution of the dendrites, helping researchers assess the impact of dendrites on battery performance and determine the relationship between electrode microstructure and performance.

[0045] The advantages of the electrochemical performance of the electrode materials prepared in the embodiments of this application are further discussed below in conjunction with the detection and characterization of the electrode materials, symmetrical button cells, and half cells obtained by the examples and comparative examples.

[0046] Figure 1 The SEM image of Zn@In-PVDF shows that the surface of Zn@In-PVDF has a large number of pores and PVDF nanoparticles, forming a three-dimensional cross-linked and dendritic structure. This morphology is conducive to accelerating the rapid and uniform deposition / exfoliation of zinc ions.

[0047] Figure 2 The graph shows the cycle performance of symmetrical button batteries assembled from the materials prepared in Example 1 and Comparative Examples 1 to 3. The horizontal axis represents time, and the vertical axis represents voltage. As can be seen from the graph, the organic / inorganic Zn@In-PVDF material prepared in Example 1 has an overpotential of only about 8 mV in the early stage of battery cycling and maintains an overpotential of about 15 mV at the end of the cycle. The low overpotential indicates a low energy barrier for metal nucleation, which is beneficial for promoting efficient metal deposition. The Zn@In-PVDF material prepared in Example 1 exhibits good performance at a current density of 1 mA / cm². -2 The deposition capacity is 1 mAh / cm³. -2Under the test conditions, it can cycle for 1000 hours with almost constant overpotential. In contrast, the comparative electrode material Zn@In single protective layer maintains a cycle life of 600 hours, the comparative electrode material Zn@PVDF has a cycle life of approximately 160 hours, and the comparative electrode material Bare-Zn only cycles for a very short time before experiencing drastic voltage fluctuations, ultimately resulting in a cycle life of less than 100 hours. Therefore, the composite coating prepared according to Example 1 can improve the stability of the battery and the long cycle life of symmetrical batteries, and... Figure 2 It can be seen that the battery modified with organic / inorganic bilayer has the smallest overpotential during cycling, which can effectively accelerate zinc ion nucleation.

[0048] Figure 3 The graph shows the cycle performance test results of the symmetrical button cell in Comparative Example 4, with the horizontal axis representing time and the vertical axis representing voltage. As can be seen from the graph, the cycle life of this symmetrical button cell can reach 900 hours, which is higher than that of symmetrical button cells based on BareZn, Zn@In, and Zn@PVDF, but lower than that of the symmetrical button cell in Example 1. Furthermore, the overpotential of the symmetrical button cell in Comparative Example 4 is also higher than that of the symmetrical button cell in Example 1. This indicates that the organic / inorganic composite coating based on the indium and PVDF layers can more effectively improve the cycle life of the battery compared to the organic / inorganic composite coating based on Cu and PVDF. The lower overpotential also indicates a lower zinc ion nucleation energy barrier.

[0049] Figure 4 The figures show the electrochemical impedance spectroscopy (EIS) curves of the electrode materials obtained in Examples 1 and Comparative Examples 1 to 3. Impedance is a vector, with the horizontal axis (Z') being its real part and the vertical axis (Z") being its imaginary part. As can be seen from the figures, Zn@In-PVDF has the lowest charge transfer resistance (Rp), while Zn@In and Zn@PVDF have slightly higher charge transfer resistances (Rp) than Zn@In-PVDF. Bare-Zn exhibits the highest charge transfer resistance (Rp). The lower charge transfer resistance indicates that Zn@In-PVDF has better charge transfer kinetics, which can effectively improve the transport capacity of ions and electrons.

[0050] Figure 5 This chart shows the rate performance test results for symmetric coin cells based on Bare-Zn, Zn@In, Zn@PVDF, and Zn@In-PVDF. During testing, the deposition capacity was 1 mAh cm⁻¹. -2 The current density was selected as 0.3 mA cm⁻¹. -2 0.6mA cm -2 1 mA cm -2 3 mA cm -2 6 mA cm -2The cells were cycled 10 times at each current density. Both Zn@In-PVDF and Zn@In exhibited good reversibility, but as shown in the figure, the Zn@In-PVDF / / Zn@In-PVDF symmetrical button cell showed a lower overpotential than the Zn@In / / Zn@In symmetrical button cell at different current densities. Zn@PVDF developed a short circuit after cycling for a period of time, while the Bare-Zn / / Bare-Zn symmetrical button cell developed a short circuit very quickly.

[0051] Figure 6 This is a rate performance test chart for Zn@Cu-PVDF symmetric solar cells. During the tests, the deposition capacity was 1 mAh cm⁻¹. -2 The current density was selected as 0.3 mA cm⁻¹. -2 0.6 mA cm -2 1 mA cm -2 3 mA cm -2 6 mAcm -2 Each current density was cycled for 10 cycles. As shown in the figure, Zn@Cu-PVDF maintained good reversibility after cycling at different rates, but the overpotential of the Zn@Cu-PVDF symmetric cell was greater than that of Zn@In-PVDF.

[0052] Figure 7 For half-cells based on Bare-Zn, Zn@In, Zn@PVDF and Zn@In-PVDF, at 1 mA cm⁻¹ -2 1mAh cm -2 The coulombic efficiency of the Bare Zn half-cell shows a sharp fluctuation after 30 cycles, while the Zn@PVDF half-cell fluctuates after 50 cycles. The Zn@In half-cell, however, only shows fluctuation after 140 cycles, indicating that Zn@PVDF and Zn@In can improve hydrogen evolution and dendrite problems to some extent. Zn@In-PVDF, on the other hand, maintains stable coulombic efficiency after 650 cycles, demonstrating the best reversibility of zinc deposition / stripping and effectively suppressing hydrogen evolution side reactions.

[0053] Referring to the figures above, this embodiment of the application constructs a composite coating based on an indium layer and a PVDF layer on a zinc metal substrate (e.g., zinc sheet). Its surface morphology consists of a three-dimensional cross-linked and dendritic structure formed by numerous pores and PVDF nanoparticles. This morphology facilitates the rapid and uniform deposition / stripping of zinc ions. Furthermore, based on the results of cycle performance testing, EIS testing, rate performance testing, and coulombic efficiency testing, the Zn@In-PVDF material prepared in Example 1 has a lower overpotential than the comparative anode materials prepared in each comparative example (averaging only about 12 mV over 1000 h) and possesses the longest cycle life. The Zn@In-PVDF material prepared in Example 1 also exhibits good reversibility and maintains a low overpotential at different current densities. The Zn@In-PVDF material prepared in Example 1 has the lowest charge transfer resistance (Rp) and possesses better zinc ion transport capability. The Zn@In-PVDF material prepared in Example 1 maintained a stable coulombic efficiency in its half-cell within 650 cycles, exhibiting better zinc deposition / stripping reversibility, thereby suppressing zinc dendrite growth. The anode material with a composite coating prepared in this application, based on the good conductivity and zinc affinity of the indium layer, and the hydrophobicity of the PVDF layer which helps reduce free water content, mitigates interfacial side reactions at the anode of the zinc-ion battery, thereby achieving stable zinc deposition / dissolution behavior and effectively improving the battery's cycle life.

[0054] The above description of the structure, features and effects of this application is based on the embodiments shown in the drawings. The above are only preferred embodiments of this application, but this application does not limit the scope of implementation to what is shown in the drawings. Any changes made in accordance with the concept of this application, or modifications to equivalent embodiments with equivalent changes, that do not exceed the spirit covered by the specification and drawings, should be within the protection scope of this application.

Claims

1. A method for preparing an inorganic / organic composite coating material for an aqueous zinc-ion battery, characterized in that, Includes the following steps: A zinc metal matrix is ​​provided, and the zinc metal matrix is ​​pretreated; An indium ion solution is prepared, and a zinc metal substrate is placed in the indium ion solution to react and obtain an indium layer. Then, the substrate is removed, rinsed, and dried. A PVDF / NMP solution is prepared, and a zinc metal substrate with an indium layer is placed into the PVDF / NMP solution to react and obtain a PVDF layer. After drying, an inorganic / organic composite coating material for aqueous zinc-ion batteries is obtained.

2. The preparation method according to claim 1, characterized in that, The preprocessing includes: Prepare a hydrochloric acid solution, immerse the zinc metal substrate in the hydrochloric acid solution and sonicate it, then remove the zinc metal substrate, rinse it with deionized water and ethanol, and dry it.

3. The preparation method according to claim 1, characterized in that, The steps for preparing the indium ion solution include: Mix InN3O9, C6H5Na3O7·2H2O and deionized water in a certain proportion and then stir.

4. The preparation method according to claim 3, characterized in that, The molar amounts of InN3O9 and C6H5Na3O7·2H2O are both 2.5 mmol, and the ratio is 1:

1.

5. The preparation method according to claim 1, characterized in that, The steps for preparing the PVDF / NMP solution include: Dissolve PVDF powder in NMP solution and stir.

6. The preparation method according to claim 5, characterized in that, 33.3 mg of PVDF should be added to every 10 mL of NMP.

7. The preparation method according to claim 1, characterized in that, The drying method is to dry the food in a vacuum environment.

8. The application of an inorganic / organic composite coating material for an aqueous zinc-ion battery, characterized in that, The inorganic / organic composite coating material obtained by the preparation method according to any one of claims 1 to 7 is used as an electrode material to make an electrode sheet, which is then applied to an aqueous zinc-ion battery.

9. The application according to claim 8, characterized in that, The electrode sheet is the negative electrode sheet of an aqueous zinc-ion battery.

10. The application according to claim 8, characterized in that, The electrode plates include: Zinc metal matrix; An indium layer formed on the zinc metal substrate by a substitution reaction; and A PVDF layer is formed on the indium body by an impregnation method.

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