A three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries and a preparation method and application thereof

Abstract

The application discloses a three-dimensional tower-shaped zinc negative electrode for aqueous zinc ion batteries and a preparation method and application thereof, and relates to the technical field of aqueous zinc ion batteries. The preparation method comprises the following steps: taking a copper foil as a working electrode, a zinc sheet as a counter electrode, and placing the copper foil and the zinc sheet in an electroplating solution to perform electroplating; after the electroplating is completed, a zinc plating layer is formed on the surface of the copper foil, and thus the three-dimensional tower-shaped zinc negative electrode for aqueous zinc ion batteries is obtained; and the electroplating solution is composed of a conductive salt, a zinc salt, isomalt and water. In the application, the copper foil is taken as the working electrode, the zinc sheet is taken as the counter electrode, the electroplating solution composed of the conductive salt, the zinc salt and the isomalt is adopted, and the zinc layer is electroplated on the surface of the copper foil through the electroplating process. The zinc plating layer has a clear three-dimensional tower-shaped structure, can provide stable sites for the deposition / dissolution of zinc, buffer volume changes, inhibit the growth of dendrites and corrosion from the structural and chemical aspects, and thus the cycle stability and safety performance of the aqueous zinc ion battery are improved.

Description

Technical Field

[0001] This invention relates to the field of aqueous zinc-ion battery technology, and particularly to a three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries, its preparation method, and its application. Background Technology

[0002] In the development of aqueous zinc-ion batteries (AZIBs), the stability of the zinc anode is a key issue restricting its performance improvement. Although zinc has advantages such as high theoretical capacity (820 mAh / g) and abundant resources, it is prone to dendrite growth and corrosion during cycling. This can not only puncture the separator and cause short circuits, but also lead to a decrease in coulombic efficiency and a shortened cycle life, seriously hindering the practical application of AZIBs.

[0003] To address the aforementioned problems, constructing a uniform and dense zinc coating on the surface of copper foil current collectors has become an effective strategy. Copper foil is widely used as a current collector due to its excellent conductivity and moderate cost. However, the significant differences in crystal structures between copper and zinc mean that direct zinc deposition can easily lead to uneven nucleation, exacerbating dendrite growth. Furthermore, copper may dissolve in aqueous electrolytes and undergo a displacement reaction with zinc, compromising electrode stability. Pre-forming a zinc coating on the copper foil surface through electroplating achieves homogeneous zinc-zinc deposition, lowering the nucleation energy barrier, inhibiting dendrite growth, and simultaneously isolating copper from the electrolyte, reducing corrosion. In the electroplating process, the choice of electroplating solution is crucial. Currently, the commonly used electroplating solutions for zinc plating on copper foil are zinc chloride plating solutions or zinc sulfamate plating solutions. Zinc chloride, with its chloride ions, is extremely corrosive to both copper foil and plating equipment, requiring the addition of large amounts of corrosion inhibitors. Furthermore, the plating layer is prone to dendrite defects, directly affecting the battery's cycle stability. Zinc sulfamate plating solutions are too expensive, with raw material prices 5-8 times higher than zinc sulfate. The plating solution is also extremely sensitive to impurities such as calcium; even trace amounts can lead to pinholes in the plating layer. Therefore, by controlling the composition of the plating solution to form a uniform, dense, and strongly bonded zinc coating on the copper foil surface, inhibiting dendrite growth and corrosion, and improving the cycle stability and safety performance of aqueous zinc-ion batteries, the development of AZIBs will be greatly promoted. Summary of the Invention

[0004] To address the shortcomings of existing technologies, one objective of this invention is to provide a method for preparing a three-dimensional, tower-shaped zinc anode for aqueous zinc-ion batteries. Using the zinc anode prepared according to this invention in aqueous zinc-ion batteries promotes uniform zinc ion deposition, inhibits zinc dendrite growth, and simultaneously prevents water molecules from contacting the zinc metal surface, reducing hydrogen evolution reactions and zinc metal corrosion side reactions, thus exhibiting excellent electrochemical performance. This is specifically achieved through the following techniques.

[0005] A method for preparing a three-dimensional tower-shaped zinc anode for an aqueous zinc-ion battery includes the following steps:

[0006] Using copper foil as the working electrode and zinc sheet as the counter electrode, the electrodes are placed in an electroplating solution for electroplating. After electroplating, a zinc coating is formed on the surface of the copper foil, thus obtaining the three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery. The electroplating solution is composed of conductive salt, zinc salt, isomaltitol, and water.

[0007] This invention uses copper foil as the working electrode and zinc sheet as the counter electrode. An electroplating solution composed of conductive salt, zinc salt, and isomaltitol is used to electroplat a zinc layer onto the copper foil surface. This process yields a uniform, dense, and strongly bonded zinc coating, resulting in a stable and dense three-dimensional "tower-like" zinc anode. This structure provides stable sites for zinc deposition / dissolution, buffers volume changes, and inhibits dendrite growth and corrosion from structural and chemical perspectives, thereby improving the cycle stability and safety performance of aqueous zinc-ion batteries. In the electroplating solution, zinc salt serves as the main salt, providing a source of zinc ions for electroplating; conductive salt significantly improves the conductivity of the plating solution and optimizes current distribution; isomaltitol, as an organic additive, adsorbs onto the active sites on the copper foil surface through its multi-hydroxyl structure, forming an organic film that hinders the rapid deposition of zinc ions in highly active areas, promotes uniform zinc ion nucleation, and inhibits zinc dendrite growth. Simultaneously, it coordinates with zinc ions, reducing the concentration of free zinc ions, slowing the reduction rate, refining grains, and improving the density and uniformity of the coating. In addition, isomaltitol can form a protective layer on the zinc surface, blocking water molecules from contacting the zinc surface, thereby reducing hydrogen evolution reaction and corrosion side reactions.

[0008] Preferably, the concentration of the conductive salt in the electroplating solution is 0.1~1.0 mol / L.

[0009] Preferably, the conductive salt includes at least one of Na₂SO₄, NaCl, and sodium perchlorate. The sodium ions it contains can compete with zinc ions for adsorption, moderately inhibiting the excessively rapid reduction of zinc ions and avoiding uneven local deposition.

[0010] Preferably, the concentration of the zinc salt in the electroplating solution is 0.1~1.0 mol / L. The concentration of the zinc salt affects the zinc deposition rate and coating morphology; a suitable concentration ensures a balanced supply of zinc ions, laying the foundation for a uniform coating.

[0011] Preferably, the zinc salt includes at least one of ZnSO4, ZnCl2, and Zn(NO3)2.

[0012] Preferably, the concentration of isomaltitol in the electroplating solution is 0.01wt%~0.05wt%.

[0013] Preferably, the electroplating conditions are as follows: electroplating current density is 50~150 mA / cm². 2The electroplating time is 20~150 minutes. By controlling the current density and time of electroplating, the thickness of the zinc coating on the copper foil surface can be adjusted.

[0014] Preferably, the thickness of the zinc coating is 1~5 μm.

[0015] Preferably, the capacity density of the zinc coating is 1~25 mAh / cm³. 2 .

[0016] The present invention also provides a zinc anode for an aqueous zinc-ion battery prepared by the above preparation method. The zinc anode has a three-dimensional tower structure, which effectively inhibits the corrosion reaction on the zinc metal surface, reduces the phenomenon of excessive local current, and makes the electric field uniformly distributed. It also provides more nucleation sites, promotes the uniform deposition of zinc ions, and exhibits excellent cycle stability and high coulombic efficiency.

[0017] The present invention also provides an application of the zinc anode prepared by the above preparation method in an aqueous zinc-ion battery.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] 1. This invention uses an electroplating solution composed of conductive salt, zinc salt, and isomaltitol. Isomaltitol is used as an additive in the electroplating solution to improve the smoothness and adhesion, making the zinc coating more uniform and dense, thereby improving the performance of the negative electrode material. At the same time, isomaltitol has high stability and does not hydrolyze under strong acid and alkali conditions. It will not react chemically with other components in the plating solution, which helps to reduce side reactions during the electroplating process, such as hydrogen evolution reaction, and improves electroplating efficiency and coating purity.

[0020] 2. The method of this invention can obtain a uniform and dense zinc coating on the surface of copper foil. This uniform and dense zinc coating helps to suppress the growth of zinc dendrites, reduce the risk of internal short circuits in the battery, and thus improve the cycle stability and service life of aqueous zinc-ion batteries. At the same time, good coating adhesion also helps to improve the battery's charge and discharge efficiency and energy density.

[0021] 3. The zinc anode prepared by this invention exhibits a unique three-dimensional tower-like structure.

[0022] 4. The aqueous zinc-ion battery prepared using the zinc anode of the present invention has a stable and suitable polarization voltage, and has excellent cycle stability, coulombic efficiency, battery storage performance and reversibility. Attached Figure Description

[0023] Figure 1 Comparison of ISO-Cu@Zn prepared in Example 1 and ordinary Cu@Zn prepared in Comparative Example 1;

[0024] Figure 2 SEM images of ISO-Cu@Zn prepared in Example 1 and ordinary Cu@Zn prepared in Comparative Example 1;

[0025] Figure 3 XRD patterns of Zn, Cu, ISO-Cu@Zn prepared in Example 1, and ordinary Cu@Zn prepared in Comparative Example 1;

[0026] Figure 4 Long-cycle performance and charge-discharge curves of ISO-Cu@Zn / / ISO-Cu@Zn and ordinary Cu@Zn / / ordinary Cu@Zn symmetrical cells;

[0027] Figure 5 Coulombic efficiency and charge-discharge curves for ISO-Cu@Zn / / Cu and ordinary Cu@Zn / / Cu half-cells;

[0028] Figure 6 ISO-Cu@Zn / / (NH4) x VO3 and ordinary Cu@Zn / / (NH4) x Comparison of cycle performance and charge / discharge curves of VO3 full batteries;

[0029] Figure 7 ISO-Cu@Zn / / (NH4) x Cyclic voltammetry (CV) performance test chart of VO3 full cell;

[0030] Figure 8 To cascade three ISO-Cu@Zn / / (NH4) atoms x Voltage display diagram and light bulb test diagram of VO3 full battery;

[0031] Figure 9 The figures show the coulombic efficiency and charge / discharge curves of the ISO-Cu@Zn / / Cu half-cell and the ordinary Cu@Zn / / Cu half-cell in Example 3. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention provides a method for preparing a three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries, comprising the following steps:

[0034] Using copper foil as the working electrode and zinc sheet as the counter electrode, the electrodes are placed in an electroplating solution for electroplating. After electroplating, a zinc coating is formed on the surface of the copper foil, thus obtaining the three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery. The electroplating solution is composed of conductive salt, zinc salt, isomaltitol, and water.

[0035] In some embodiments, the volume of the electroplating solution is 50 mL; in other embodiments, the volume of the electroplating solution is 100 mL.

[0036] In some embodiments, the concentration of the conductive salt in the electroplating solution is 0.1 mol / L; in other embodiments, the concentration of the conductive salt in the electroplating solution is 1.0 mol / L; and in some preferred embodiments, the concentration of the conductive salt in the electroplating solution is 0.5 mol / L.

[0037] In some embodiments, the concentration of zinc salt in the electroplating solution is 0.1 mol / L; in other embodiments, the concentration of zinc salt in the electroplating solution is 1.0 mol / L; and in some preferred embodiments, the concentration of zinc salt in the electroplating solution is 0.5 mol / L.

[0038] In some embodiments, the conductive salt is sodium perchlorate; in other embodiments, the conductive salt is NaCl; and in some preferred embodiments, the conductive salt is Na2SO4.

[0039] In some embodiments, the zinc salt is ZnCl2; in other embodiments, the zinc salt is Zn(NO3)2; and in some preferred embodiments, the zinc salt is ZnSO4.

[0040] In some embodiments, the concentration of isomaltitol in the electroplating solution is 0.01 wt%; in other embodiments, the concentration of isomaltitol in the electroplating solution is 0.03 wt%; and in some preferred embodiments, the concentration of isomaltitol in the electroplating solution is 0.05 wt%.

[0041] In some embodiments, the electroplating conditions are as follows: the electroplating current density is 50~150 mA / cm². 2 The electroplating time is 20~150min.

[0042] In some embodiments, the thickness of the zinc coating is 1~5 μm.

[0043] In some embodiments, the capacity density of the zinc coating is 1~25 mAh / cm³. 2 .

[0044] In the above preparation method, the copper foil and zinc sheet have the same dimensions. For example, the length × width is not less than 4 cm × 4 cm, and the thickness is 0.02 mm.

[0045] Example 1

[0046] This embodiment provides a method for preparing a three-dimensional tower-shaped zinc anode for an aqueous zinc-ion battery. The specific steps are as follows:

[0047] (1) Prepare the electroplating solution, which consists of Na2SO4, ZnSO4, isomaltitol and water. The concentrations of ZnSO4 and Na2SO4 in the electroplating solution are both 0.5 mol / L, and the concentration of isomaltitol in the electroplating solution is 0.05 wt%.

[0048] The electrochemical workstation was programmed with an initial current and time of 0, and the electroplating current was set to 150 mA / cm². 2 Set the electroplating time to 1 hour;

[0049] The cleaned high-purity zinc sheet and copper foil were cut into squares with sides of 4cm × 4cm.

[0050] (2) Place the bright side of the copper foil and the front side of the zinc plate together in 100mL of electroplating solution, using the copper foil as the working electrode and the zinc plate as the counter electrode, and perform electroplating.

[0051] (3) After electroplating, remove the material from the working electrode and rinse its surface with deionized water 2-3 times; after rinsing clean, dry it to obtain a tower-shaped copper-zinc composite material (ISO-Cu@Zn) with zinc plating on the copper foil surface.

[0052] Comparative Example 1

[0053] This comparative example is basically the same as Example 1, except that the electroplating solution in this comparative example is composed of Na2SO4, ZnSO4 and water, and the concentrations of ZnSO4 and Na2SO4 in the electroplating solution are both 0.5 mol / L.

[0054] Figure 1 The figures show a comparison of ISO-Cu@Zn prepared in Example 1 and ordinary Cu@Zn prepared in Comparative Example 1. As can be seen from the figures, the zinc coating on the copper foil surface in ISO-Cu@Zn is more uniform.

[0055] Figure 2SEM images of ISO-Cu@Zn prepared in Example 1 and ordinary Cu@Zn prepared in Comparative Example 1 are shown. Images c and d are SEM images of ordinary Cu@Zn, showing that zinc is deposited on the copper foil surface in a needle-like form, which accelerates zinc dendrite penetration of the separator and shortens battery life. Images a and b are SEM images of ISO-Cu@Zn, showing that the zinc coating on the copper foil surface has a distinct three-dimensional "tower-like" structure. This indicates that the improved electroplating solution, with the addition of isomaltitol to the conventional electroplating solution, can induce uniform zinc deposition on the copper foil, ultimately obtaining a three-dimensional "tower-like" structure, thus providing more nucleation sites and effectively delaying zinc dendrite growth.

[0056] Figure 3 XRD patterns of Zn, Cu, ISO-Cu@Zn prepared in Example 1, and ordinary Cu@Zn prepared in Comparative Example 1 are shown. The figures show that the characteristic peak of Zn appears in ISO-Cu@Zn, indicating that Zn was successfully electroplated onto the surface of the copper foil. This is consistent with the PDF cards for Cu and Zn, indicating that there are essentially no impurities. X-ray diffraction characterization revealed that the I(002) / I(101) peak intensity ratio in ISO-Cu@Zn was 1.5050, while the ratio in ordinary Cu@Zn was 0.6357. ISO-Cu@Zn has a larger proportion of the (002) crystal plane; this induces uniform deposition of zinc ions on the (002) crystal plane, resulting in a uniform and dense three-dimensional tower-like structure in the zinc coating, effectively preventing the formation of zinc dendrites and side reactions. Ordinary Cu@Zn, on the other hand, induces zinc ions to deposit on the (101) crystal plane.

[0057] Application examples

[0058] (1) Assemble a Zn / / Zn symmetric cell and conduct a long-cycle test at 25°C.

[0059] Both the ordinary Cu@Zn of Comparative Example 1 and the ISO-Cu@Zn of Example 1 were stamped into discs with a diameter of 12 mm to obtain two types of electrodes: ordinary Cu@Zn and ISO-Cu@Zn. Then, using these two types of electrodes as negative and positive electrodes, two sets of Zn / / Zn symmetrical cells were assembled, namely, the ordinary Cu@Zn / / ordinary Cu@Zn symmetrical cell and the ISO-Cu@Zn / / ISO-Cu@Zn symmetrical cell.

[0060] Taking ISO-Cu@Zn as an example, the assembly process is as follows: First, place the ISO-Cu@Zn negative electrode sheet into the 2025 negative electrode shell, with the smooth side facing up; then, place a 16 mm diameter glass fiber separator, and drop 2-3 drops of 2 mol / L zinc sulfate solution as the electrolyte to completely wet the glass fiber separator; next, place the ISO-Cu@Zn as the positive electrode sheet on top of the glass fiber separator, with the zinc-plated side facing down in contact with the separator; finally, place a 1.0 mm thick 304 stainless steel gasket and a 1.2 mm thick 304 stainless steel spring sheet, and finally, close the 2025 positive electrode shell. Use a battery packaging machine to package the battery, thus obtaining one 2025 standard model ISO-Cu@Zn aqueous zinc-ion symmetric button cell, i.e., ISO-Cu@Zn / / ISO-Cu@Zn symmetric battery.

[0061] Correspondingly, a standard Cu@Zn / / standard Cu@Zn symmetric cell was also assembled.

[0062] The assembled symmetrical cell was tested on the Blue Electricity Testing System at 5 mA / cm². 2 The current density was used to conduct constant current charge / discharge tests, following the sequence of rest, constant current charging, rest, and constant current discharging. The rest period was 30 seconds, and the constant current charge / discharge time was 12 minutes to test the cycle stability of the battery.

[0063] The comparison charts and charge-discharge curves of the long-cycle performance of ISO-Cu@Zn / / ISO-Cu@Zn and ordinary Cu@Zn / / ordinary Cu@Zn symmetric batteries are shown below. Figure 4 As shown in the figures; Figure a shows the long-cycle performance of the two sets of symmetrical cells. It can be seen that the ordinary Cu@Zn / / ordinary Cu@Zn symmetrical cell short-circuited after 185 h, while the ISO-Cu@Zn / / ISO-Cu@Zn symmetrical cell cycled stably for more than 400 h, demonstrating excellent cycle stability. Figures b and c are the charge-discharge curves of the ISO-Cu@Zn / / ISO-Cu@Zn and ordinary Cu@Zn / / ordinary Cu@Zn symmetrical cells at the 50th, 100th, 200th, and 250th cycles, respectively. It can be seen from the figures that the ISO-Cu@Zn / / ISO-Cu@Zn symmetrical cell has the lowest polarization voltage of only 74 mV, while the ordinary Cu@Zn / / ordinary Cu@Zn symmetrical cell has a polarization voltage of 91 mV, indicating that the zinc anode prepared by the present invention can significantly reduce the polarization voltage.

[0064] (2) Assemble a Zn / / Cu half-cell and perform coulombic efficiency test at 25℃.

[0065] The Zn / / Cu half-cell uses a similar assembly process to the Zn / / Zn symmetrical cell. The difference is that the positive electrode of the Zn / / Cu half-cell uses pure copper foil (12 mm in diameter), and the negative electrode uses ordinary Cu@Zn and ISO-Cu@Zn electrodes, respectively. Finally, two sets of Zn / / Cu half-cells are assembled in sequence, namely ordinary Cu@Zn / / Cu half-cell and ISO-Cu@Zn / / Cu half-cell.

[0066] The assembled half-cell was tested on the Blue Electricity testing system at 5 mA / cm². 2 The current density was used to conduct constant current charge and discharge tests, following the sequence of rest, constant current discharge, rest, and constant current charge. The rest period was 30 seconds for each test, and the constant current charge and discharge time was 12 minutes. The coulombic efficiency of the battery was then tested.

[0067] The coulombic efficiency and charge-discharge curves of ISO-Cu@Zn / / Cu half-cells and ordinary Cu@Zn / / Cu half-cells are shown in the figure below. Figure 5 As shown in Figure a, the coulombic efficiency of the two half-cells is as follows: Figure a shows the coulombic efficiency of the ISO-Cu@Zn / / Cu half-cell. It can be seen from the figure that the ISO-Cu@Zn / / Cu half-cell achieved ultra-stable cycling for over 700 cycles, with a coulombic efficiency consistently above 99.9%, exhibiting more stable cycling performance compared to the ordinary Cu@Zn / / Cu half-cell. Figures b and c show the charge-discharge curves of the ISO-Cu@Zn / / Cu half-cell and the ordinary Cu@Zn / / Cu half-cell at cycles 50, 100, and 200, respectively. It can be seen that the polarization voltage of the ISO-Cu@Zn / / Cu half-cell is 114 mV, while that of the ordinary Cu@Zn / / Cu half-cell is 216 mV. This indicates that the zinc anode prepared using this invention can improve the coulombic efficiency and significantly reduce the polarization voltage.

[0068] (3) Zn / / (NH4) x VO3 full battery undergoes cycle stability testing at 25°C.

[0069] Zn / / (NH4) x The structure of the VO3 full cell is basically the same as that of the Zn / / Zn symmetric cell, the difference being that the positive electrode uses (NH4) with a diameter of 12 mm. x The VO3 electrode uses two types of electrodes, the ordinary Cu@Zn and ISO-Cu@Zn, with a diameter of 15 mm, respectively. Finally, two sets of Zn / / (NH4) are assembled sequentially. x VO3 full cell, i.e., ordinary Cu@Zn / / (NH4) x VO3 full cell and ISO-Cu@Zn / / (NH4) x VO3 full battery.

[0070] (NH4) xThe preparation method of VO3 electrode is as follows: First, 0.468 g of NH4VO3 is dissolved in deionized water at 70℃, 0.7612 g of thiourea is added, and dilute sulfuric acid is added dropwise to adjust the pH to 2.0. The mixture is stirred at 90℃ for 2.5 h. Then, it is filtered, washed, and dried at 60℃ for 24 h to obtain (NH4). x VO3 cathode material; then, the cathode material, acetylene black, and PVDF (polyvinylidene fluoride) are mixed in a mass ratio of 7:2:1, and N-methylpyrrolidone is added to form a slurry. This slurry is coated onto carbon paper and dried at 60℃ for 24 h. The slurry coating should have a minimum thickness of 2 mg / cm² after drying. 2 It was cut into electrodes with a diameter of 12 mm to obtain (NH4). x VO3 film.

[0071] The assembled battery was tested on the Blue Electric testing system, where it was subjected to constant current charging / discharging at a current density of 5 A / g, with the charge / discharge range set to 0.4~1.8 V, to test the battery's cycle stability.

[0072] ISO-Cu@Zn / / (NH4) x VO3 full cell and ordinary Cu@Zn / / (NH4) x The comparison chart of the cycle performance and the charge / discharge curve of the VO3 full battery are as follows: Figure 6 As shown in the figure, Figure a presents the cycle performance of two sets of full cells. It can be seen from the figure that ISO-Cu@Zn / / (NH4) x The initial specific capacity of the VO3 full cell, at 190 mAh / g, is significantly higher than that of ordinary Cu@Zn / / (NH4). x VO3 full cells exhibit better cycle stability. Figures b and c show ISO-Cu@Zn / / (NH4) respectively. x VO3 full cell and ordinary Cu@Zn / / (NH4) x The charge-discharge curves of the VO3 full cell show that in the battery system using ordinary Cu@Zn as the negative electrode, the charge-discharge plateau decays rapidly; while in the battery system using ISO-Cu@Zn as the negative electrode, the charge-discharge plateau is more stable at different cycle numbers, and the plateau decays slowly with increasing cycle number. This indicates that the ISO-Cu@Zn negative electrode of this invention can significantly improve the long-cycle stability of zinc-ion batteries, and the addition of isomaltitol optimizes the battery performance.

[0073] (4) Cyclic voltammetry (CV) performance test was conducted under constant temperature conditions of 25℃.

[0074] Cyclic CV tests were performed on the full cell assembled using ISO-Cu@Zn as the negative electrode in Example 1. The test conditions were: CHI660E electrochemical workstation, voltage range of 0.4~1.4V and scan rate of 1~10 mV / s.

[0075] ISO-Cu@Zn / / (NH4) was assembled using ISO-Cu@Zn as the negative electrode. x The cyclic voltammetry (CV) performance test results of the VO3 full cell under isothermal conditions at 25°C are as follows: Figure 7 As shown, the oxidation / reduction peaks stabilize as the scan rate increases, indicating faster charge transport, lower internal resistance, and high symmetry between the oxidation and reduction peaks, thus demonstrating good reversibility of the reaction.

[0076] ISO-Cu@Zn / / (NH4) was assembled using ISO-Cu@Zn as the negative electrode. x Voltage and application testing of three stacked VO3 full-cell batteries, as follows: Figure 8 As shown in Figure a, three ISO-Cu@Zn / / (NH4) atoms can be observed. x The voltage of the stacked VO3 full cells measured with a multimeter was 4.672 V. Figure b shows the three stacked ISO-Cu@Zn / / (NH4) atoms. x VO3 fully powered LED light strip.

[0077] Example 2

[0078] The preparation method of the three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries in this embodiment is basically the same as that in Example 1, except that the concentration of isomaltitol in the electroplating solution is 0.01 wt%.

[0079] Example 3

[0080] The preparation method of the three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries in this embodiment is basically the same as that in Example 1, except that the concentration of isomaltitol in the electroplating solution is 0.03 wt%.

[0081] The ISO-Cu@Zn prepared in Example 3 was stamped into a disc with a diameter of 12 mm and used as the negative electrode. The positive electrode was made of pure copper foil (12 mm in diameter), and the ISO-Cu@Zn / / Cu half cell was assembled.

[0082] The coulombic efficiency and polarization voltage comparison diagram of the ISO-Cu@Zn / / Cu half-cell and the ordinary Cu@Zn / / Cu half-cell in Example 3 is shown in the figure below. Figure 9As shown in Figure a, which depicts the coulombic efficiency of the two half-cells, it can be seen that the ISO-Cu@Zn / / Cu half-cell achieves ultra-stable cycling for over 700 cycles, with a coulombic efficiency consistently above 99.9%, exhibiting more stable cycling performance compared to the ordinary Cu@Zn / / Cu half-cell. Figures b and c compare the polarization voltages of the ISO-Cu@Zn / / Cu and ordinary Cu@Zn / / Cu half-cells at cycles 50, 100, and 200, respectively. It can be observed that the polarization voltage of the ISO-Cu@Zn / / Cu half-cell is 98 mV, while that of the ordinary Cu@Zn / / Cu half-cell is 216 mV, indicating that the zinc anode prepared using this invention can improve the coulombic efficiency and significantly reduce the polarization voltage.

[0083] Example 4

[0084] The preparation method of the three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries in this embodiment is basically the same as that in Example 1, except that the electroplating time is set to 0.5 h.

[0085] Example 5

[0086] The preparation method of the three-dimensional tower-shaped zinc anode for aqueous zinc-ion batteries in this embodiment is basically the same as that in Example 1, except that the high-purity zinc sheet and copper foil are cut into squares with a side length of 6 cm × 6 cm.

[0087] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A method for preparing a three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery, characterized in that, Includes the following steps: Using copper foil as the working electrode and zinc sheet as the counter electrode, the electrodes are placed in an electroplating solution for electroplating. After electroplating, a zinc coating is formed on the surface of the copper foil, thus obtaining the three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery. The electroplating solution consists of a conductive salt, a zinc salt, isomaltitol, and water. The conductive salt includes at least one of Na2SO4, NaCl, and sodium perchlorate. The zinc salt includes at least one of ZnSO4, ZnCl2, and Zn(NO3)2. The concentration of isomaltitol is 0.01wt%~0.05wt%.

2. The method for preparing a three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery according to claim 1, characterized in that, In the electroplating solution, the concentration of the conductive salt is 0.1~1.0 mol / L.

3. The method for preparing a three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery according to claim 1, characterized in that, In the electroplating solution, the concentration of the zinc salt is 0.1~1.0 mol / L.

4. The method for preparing a three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery according to claim 1, characterized in that, The electroplating conditions are as follows: electroplating current density is 50~150 mA / cm 2 , and electroplating time is 20~150 min.

5. The method for preparing a three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery according to claim 1, characterized in that, The thickness of the zinc coating is 1~5 μm.

6. The method for preparing a three-dimensional tower-shaped zinc negative electrode for an aqueous zinc-ion battery according to claim 1, characterized in that, The capacity density of the zinc coating is 1~25 mAh / cm³. 2 .

7. The zinc anode for an aqueous zinc-ion battery prepared by the preparation method according to any one of claims 1 to 6, characterized in that, The zinc anode has a three-dimensional tower-like structure.

8. The application of the zinc anode for an aqueous zinc-ion battery prepared by the preparation method according to any one of claims 1 to 6, or the zinc anode for an aqueous zinc-ion battery according to claim 7, in an aqueous zinc-ion battery.

Images