Zinc negative electrode plate with three-dimensional copper foil substrate as well as preparation method and application of zinc negative electrode plate

Abstract

The invention discloses a zinc negative electrode plate with a three-dimensional copper foil substrate and a preparation method and application thereof, relates to the technical field of aqueous zinc ion batteries, and provides a preparation method of a three-dimensional copper foil substrate loaded zinc positive electrode aiming at the problems of short cycle life, low coulombic efficiency and the like caused by dendritic crystal growth and side reaction of an aqueous zinc ion battery zinc negative electrode. A three-dimensional porous structure is constructed on a zinc-loving copper foil substrate through a wet chemical method, and the method comprises the following specific steps: (1) immersing a copper foil into an acidic solution containing ferric trichloride hexahydrate for reaction to prepare a three-dimensional porous copper foil; and (2) taking a three-dimensional copper foil (3D Cu) as a substrate, and loading zinc metal through an electroplating process to obtain the three-dimensional copper foil substrate galvanized negative electrode (3D Cu-Zn). The three-dimensional porous structure can balance electric field distribution, induce uniform deposition of zinc ions, inhibit dendritic crystal growth and optimize current distribution.

Description

Technical Field

[0001] This invention relates to the field of aqueous zinc-ion battery technology, and particularly to zinc anode sheets with a three-dimensional copper foil substrate, their preparation methods, and applications. Background Technology

[0002] With the accelerating global energy structure transformation, developing safe, efficient, and sustainable energy storage technologies has become a common goal for the scientific and industrial communities. Aqueous zinc-ion batteries have received widespread attention in recent years due to their inherent safety, low cost, and environmental friendliness. Compared to the widely used lithium-ion batteries that employ flammable organic electrolytes, aqueous zinc-ion batteries utilize aqueous electrolytes, completely eliminating the safety hazards of the battery system. Simultaneously, the zinc metal anode possesses a high theoretical capacity (820 mA / g) and a low redox potential (-0.76 V vs. SHE). These excellent characteristics make it a highly promising energy storage system.

[0003] However, zinc metal anodes still face significant challenges in practical applications. Uncontrolled growth of zinc dendrites in aqueous zinc-ion batteries can lead to short circuits, severely impacting cycle life and safety. Side reactions at the zinc anode-electrolyte interface (such as hydrogen evolution and corrosion) significantly reduce coulombic efficiency. Volume changes during zinc deposition / dissolution in aqueous zinc-ion batteries also affect the stability of the electrode structure. These issues severely restrict the performance improvement and industrial application of aqueous zinc-ion batteries.

[0004] In recent years, significant progress has been made in the optimization of zinc anodes. In terms of materials design, researchers have developed various strategies to improve the performance of zinc anodes, suppress dendrite growth and side reactions, thereby obtaining zinc-ion batteries with ultra-high rate performance and excellent cycle stability. For example, methods such as improving the battery separator to optimize ion selection channels, improving the electrolyte to stabilize the hydrogen bond network of water molecules, and using mixed electrolytes to adjust the solvation structure of the electrolyte. However, these strategies primarily focus on improving the stability of ion conduction.

[0005] Therefore, for the zinc anode of aqueous zinc-ion batteries, how to suppress dendrite growth and improve the electrochemical performance of aqueous zinc-ion batteries can provide different development ideas for the technology of aqueous zinc-ion batteries. Summary of the Invention

[0006] To address the problems of dendrite growth and poor cycle stability in zinc anodes of aqueous zinc-ion batteries, this invention provides a zinc anode sheet with a three-dimensional copper foil substrate, its preparation method, and its applications. This invention utilizes a wet chemical method to construct a copper foil with a three-dimensional porous structure as the substrate, achieving more uniform deposition and efficient stripping of zinc ions during subsequent charge-discharge processes. This three-dimensional porous copper foil can reduce the zinc deposition energy barrier, optimize current distribution, thereby suppressing dendrite growth and improving the battery's cycle performance. This invention is specifically achieved through the following techniques.

[0007] This invention provides a method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate, comprising the following steps:

[0008] Adjust the pH of the ferric chloride solution to no more than 3.0, then place the copper foil in the solution and allow it to undergo a corrosion reaction at room temperature.

[0009] Zinc foil is used as the counter electrode, and etched copper foil is used as the working electrode. The two electrodes are then placed in an electroplating solution for electroplating to obtain a zinc negative electrode sheet with a three-dimensional copper foil substrate.

[0010] Furthermore, the concentration of the ferric chloride is 0.1-3 mol / L, and the corrosion time is 10-120 min.

[0011] Furthermore, when the concentration of the ferric chloride is 0.1 mol / L, the corrosion time is not less than 1 h.

[0012] Furthermore, when the concentration of the ferric chloride is 0.3 mol / L, the corrosion time does not exceed 30 min.

[0013] Further, the pH value of the ferric chloride solution is adjusted with hydrochloric acid.

[0014] Furthermore, the electroplating conditions are 1-15 mA / cm². 2 Electroplating at the specified current density for 30-120 minutes.

[0015] Optionally, the electroplating conditions are 10 mA / cm 2 Electroplating was performed at a current density for 60 minutes.

[0016] Furthermore, the electroplating solution comprises sodium sulfate and zinc sulfate.

[0017] Furthermore, in the electroplating solution, the concentration of sodium sulfate is 0.15-0.5 mol / L, and the concentration of zinc sulfate is 0.05-0.6 mol / L;

[0018] Specifically, optionally, the concentration of sodium sulfate in the electroplating solution is 0.25 mol / L, and the concentration of zinc sulfate is 0.3 mol / L.

[0019] The present invention also provides a zinc negative electrode sheet having a three-dimensional copper foil substrate, which is prepared by any of the preparation methods described above.

[0020] This invention constructs a three-dimensional porous structure on a copper foil substrate using a wet chemical etching method. This increases the specific surface area, providing more space for zinc deposition, regulating zinc deposition behavior during electroplating, and inhibiting zinc dendrite growth. The zinc anode sheet prepared using the above method comprises a zinc-loving porous copper foil substrate and a zinc metal layer uniformly deposited on the copper foil surface. The three-dimensional porous network formed on the copper foil substrate surface by etching has a pore size distribution of 1-10 μm, and the zinc metal is uniformly loaded within the channels in a coral-like network structure.

[0021] The present invention also provides an application of a zinc negative electrode sheet with a three-dimensional copper foil substrate prepared by any of the above preparation methods in the preparation of aqueous zinc-ion batteries.

[0022] The present invention also provides an aqueous zinc-ion battery, wherein the aqueous zinc-ion battery comprises a zinc negative electrode sheet having a three-dimensional copper foil substrate prepared by any one of the preparation methods described above.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] This invention provides a method for preparing a zinc anode sheet with a three-dimensional copper foil substrate. A three-dimensional porous structure is formed by etching the surface of ordinary copper foil, allowing subsequent electroplating of metallic zinc to be uniformly deposited on the three-dimensional porous structure in a coral-like network pattern. The zinc anode sheet with this structure provided by this invention exhibits a more uniform dendrite distribution, optimizing current distribution during battery charge-discharge cycles, improving cycle stability, and extending battery life. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the fabrication process of the zinc anode sheet (3D Cu-Zn) with a three-dimensional copper foil substrate in Example 1.

[0026] Figure 2 This is a schematic diagram of a battery assembly using a symmetrical CR2025 battery case, as shown in Example 1.

[0027] Figure 3 The images show physical examples of ordinary copper foil (Cu), the material after electroplating ordinary copper foil with zinc (Cu-Zn), and the material after electroplating three-dimensional copper foil (3D Cu) with zinc (3D Cu-Zn) after wet chemical treatment.

[0028] Figure 4Scanning electron microscope (SEM) images of ordinary copper foil (Cu), three-dimensional copper foil after wet chemical treatment (3D Cu), material after electroplating zinc with ordinary copper foil (Cu-Zn), and material after electroplating zinc with three-dimensional copper foil (3D Cu-Zn).

[0029] Figure 5 X-ray diffraction (XRD) images of ordinary zinc foil (Zn), ordinary copper foil (Cu), copper foil electroplated with zinc (Cu-Zn), three-dimensional copper foil after wet chemical treatment (3D Cu), and copper foil electroplated with zinc (3D Cu-Zn) are shown. Figure a shows the XRD patterns of ordinary zinc foil (Zn), ordinary copper foil (Cu), and Cu-Zn used in all examples; Figure b shows the XRD patterns of 3D Cu and 3D Cu-Zn.

[0030] Figure 6 This is a comparison of constant current charge-discharge of three Zn / / Zn symmetric cells: ordinary Zn / / Zn, Cu-Zn / / Cu-Zn, and 3D Cu-Zn / / 3D Cu-Zn. Figure a shows the constant current charge-discharge of the three symmetric cells at 5 mA / cm². 2 The long-cycle voltage diagrams under current density are shown in Figures b and c, which are magnified views of 10 h-12 h and 448 h-450 h, respectively. Figures d, e, and f are comparison diagrams of polarization voltage for the three types of batteries at 100 cycles, 200 cycles, and 300 cycles, respectively.

[0031] Figure 7 The graphs show a comparison of constant current charge-discharge of three Zn / / Cu half-cells: ordinary Zn / / Cu, Cu-Zn / / Cu, and 3D Cu-Zn / / Cu. Figure a shows the coulombic efficiency comparison, while figures b, c, and d show the polarization voltages of the three Zn / / Cu half-cells after 1, 50, and 100 cycles, respectively.

[0032] Figure 8 For ordinary Zn / / (NH4) x VO3, Cu-Zn / / (NH4) x VO3 and 3D Cu-Zn / / (NH4) x VO3 contains these three types of Zn / (NH4) x Comparison of cycle performance of VO3 full cells. Figure a shows the coulombic efficiency comparison; figures b, c, and d show the comparison of ordinary Zn / / (NH4) cells, respectively. x VO3, Cu-Zn / / (NH4) x VO3, 3D Cu-Zn / / (NH4) x The polarization voltages of VO3 for 100, 300, 500 and 700 full-cell cycles.

[0033] Figure 9 For 3D Cu-Zn / / (NH4) x CV cycle diagram of a full VO3 cell.

[0034] Figure 10 For ordinary Zn / / (NH4) x VO3, Cu-Zn / / (NH4) x VO3 and 3D Cu-Zn / / (NH4) x VO3 and these 3 types of Zn / / NH4VO x Voltage display diagram of all batteries connected in series and test of lighting a light bulb.

[0035] Figure 11 The following are examples of symmetric 3D Cu-Zn / / 3DCu-Zn cells assembled using 3D Cu-Zn treated at different concentrations and for different times as the negative electrode: 3D Cu-Zn / / Cu half-cells, 3D Cu-Zn / / (NH4) cells. x VO3 full battery performance comparison chart. Detailed Implementation

[0036] 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.

[0037] In some embodiments of the present invention, the method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate specifically includes the following steps:

[0038] Adjust the pH of the ferric chloride solution to no more than 3.0, then place the copper foil in the solution and allow it to undergo a corrosion reaction at room temperature.

[0039] Zinc foil is used as the counter electrode, and etched copper foil is used as the working electrode. The two electrodes are then placed in an electroplating solution for electroplating to obtain a zinc negative electrode sheet with a three-dimensional copper foil substrate.

[0040] Optionally, the concentration of the selected ferric chloride solution is 0.1-3 mol / L, and the corrosion time is 10-120 min.

[0041] For example, when the concentration of ferric chloride is 0.1 mol / L, the corrosion time is not less than 1 h. When the concentration of ferric chloride is 0.3 mol / L, the corrosion time is not more than 30 min.

[0042] Optionally, hydrochloric acid can be used to adjust the pH of the ferric chloride solution. For example, a 12 mol / L hydrochloric acid solution can be selected.

[0043] Optionally, the electroplating conditions are 1-15 mA / cm 2 Electroplating at the specified current density for 30-120 minutes.

[0044] Specifically, the electroplating conditions were 10 mA / cm². 2 Electroplating was performed at a current density for 60 minutes.

[0045] Optionally, the electroplating solution comprises sodium sulfate and zinc sulfate.

[0046] Further optionally, the concentration of sodium sulfate is 0.15-0.5 mol / L, and the concentration of zinc sulfate is 0.05-0.6 mol / L.

[0047] Specifically, the concentration of sodium sulfate in the electroplating solution is 0.25 mol / L, and the concentration of zinc sulfate is 0.3 mol / L.

[0048] In some specific embodiments of the present invention, the method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate includes the following steps:

[0049] (1) Dissolve ferric chloride hexahydrate in deionized water to obtain a ferric chloride solution according to the predetermined concentration; add concentrated hydrochloric acid dropwise during the dissolution process to adjust the pH of the solution to not exceed 3.0, and avoid Fe 3+ Hydrolysis produces a precipitate.

[0050] If necessary, stirring can be performed. Optionally, the stirring speed is 350-450 r / min.

[0051] (2) Cut a 10 cm × 10 cm copper foil and place it in the above ferric chloride solution for immersion corrosion treatment at room temperature.

[0052] (3) After the etching process is completed, the prepared three-dimensional copper foil substrate is removed, cleaned with deionized water, and then wiped dry with wiping paper.

[0053] (4) Cut the zinc foil and the dried three-dimensional copper foil substrate to the same size, insert them into the pre-prepared electroplating solution, keep the two foils parallel, with a spacing of about 40 mm between them, and perform electroplating after setting the current density.

[0054] (5) After electroplating, remove the three-dimensional copper foil substrate and clean it with deionized water.

[0055] Example 1

[0056] The method for preparing a zinc negative electrode sheet on a three-dimensional copper foil substrate provided in this embodiment is as follows: Figure 1 As shown, the specific steps are as follows:

[0057] S1. Dissolve 12.165 g of FeCl3·6H2O in 150 mL of deionized water, add 12 mol / L concentrated hydrochloric acid dropwise until the pH of the solution is 3.0, stir for 30 min to completely dissolve all the ferric chloride hexahydrate, and obtain the etching solution. That is, the concentration of FeCl3 in the etching solution is 0.3 mol / L.

[0058] S2. Immerse a copper foil with a length of 10 cm, a width of 10 cm, and a thickness of 15 μm into the etching solution, let it stand at room temperature for 20 min, remove it and wash it three times with deionized water to obtain a three-dimensional copper foil substrate (3D Cu).

[0059] S3. Using 3D Cu as the working electrode, pure zinc foil as the counter electrode, and a mixed solution of ZnSO4 and NaSO4 as the electroplating solution (ZnSO4 and NaSO4 concentrations of 0.25 mol / L and 0.3 mol / L, respectively), at a current density of 5 mA / cm², the electroplating is carried out. 2 Electroplating was performed for 60 minutes, followed by drying to obtain a zinc anode sheet with a three-dimensional copper foil substrate (3D Cu-Zn anode sheet).

[0060] S4. Assemble Zn / / Zn symmetric cells, Zn / / Cu half-cells, and Zn / / (NH4) cells. x VO3 full battery.

[0061] (1) Assemble a Zn / / Zn symmetrical cell.

[0062] like Figure 2 As shown, 3D Cu-Zn electrodes are stamped into 12 mm diameter discs; using ordinary zinc foil, Cu-Zn, and 3D Cu-Zn electrodes as negative and positive electrodes respectively, three different Zn / / Zn symmetrical cells are assembled, namely ordinary Zn / / ordinary Zn, Cu-Zn / / Cu-Zn, and 3D Cu-Zn / / 3D Cu-Zn.

[0063] Taking the 3D Cu-Zn electrode as an example, the assembly process is as follows: First, place the 3D Cu-Zn negative electrode 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 3D Cu-Zn as the positive electrode on top of the glass fiber separator, with the smooth 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 a 2032 standard model 3D Cu-Zn aqueous zinc-ion symmetric button cell, i.e., a 3D Cu-Zn / / 3D Cu-Zn symmetric battery.

[0064] Correspondingly, ordinary Zn / / Zn symmetric cells and Cu-Zn / / Cu-Zn symmetric cells were also assembled.

[0065] (2) Assemble a Zn / / Cu half cell.

[0066] The Zn / / Cu half-cell employs essentially the same assembly process as the Zn / / Zn symmetric cell. The difference lies in the cathode: the Zn / / Cu half-cell uses pure copper foil (12 mm in diameter), while the anode uses three types of negative electrode sheets: ordinary zinc foil, Cu-Zn, and 3D Cu-Zn. Ultimately, ordinary Zn / / Cu half-cells, Cu-Zn / / Cu half-cells, and 3D Cu-Zn / / Cu half-cells are assembled sequentially.

[0067] (3) Assemble Zn / / (NH4) x VO3 full battery.

[0068] Zn / / (NH4) x The structure of a VO3 full cell is basically the same as that of a Zn / / Zn symmetric cell, the difference being that the positive electrode uses NH4VO3. x The electrodes, specifically the negative electrode, utilize three types of negative electrode sheets: 15 mm ordinary zinc foil, Cu-Zn, and 3D Cu-Zn. Finally, they are assembled sequentially to obtain ordinary Zn / / (NH4). x VO3 full cell, Cu-Zn / / (NH4) x VO3 full cell and 3D Cu-Zn / / (NH4) x VO3 full battery.

[0069] (NH4) x The 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 NH4VO3, 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 strength of at least 2 mg / cm² after drying. 2 It was cut into electrodes with a diameter of 12 mm to obtain (NH4). x VO3 cathode material.

[0070] S5, Performance Testing

[0071] The Zn / / Zn symmetric cells, Zn / / Cu half-cells, and Zn / / (NH4) prepared above were tested. xCycle performance of VO3 full batteries.

[0072] The test method for Zn / / Zn symmetric cells is as follows: The test method involves setting a constant current of 5 mA / cm² in the blue electric current testing system. 2 At current of 1 mAh / cm 2 Charge-discharge cycle.

[0073] The test method for Zn / / Cu half-cells is as follows: A constant current of 5 mA / cm² is set in the blue electric current testing system. 2 At current of 1 mAh / cm 2 Discharge, then constant current 5 mA / cm 2 It is charged to 1V under current, and then charged and discharged in this way.

[0074] Zn / / (NH4) x The testing method for VO3 full batteries is as follows: set the current density to 5 A / g, the charging cutoff voltage to 1.8 V, and the discharging cutoff voltage to 0.4 V in the Blue Electric test system, and cycle the charge and discharge accordingly.

[0075] Zn / / (NH4) x The cyclic voltammetry (CV) test conditions for VO3 full cells were: ChI660E electrochemical workstation, voltage range 0.4-1.4 V, scan rate 1 mV / s.

[0076] SEM images of ordinary copper foil (Cu), three-dimensional copper foil after wet chemical treatment (3D Cu), material after electroplating zinc with ordinary copper foil (Cu-Zn), and material after electroplating zinc with three-dimensional copper foil (3D Cu-Zn) are shown in Example 1. Figure 4 As shown in the figures, Figure a is a SEM image of ordinary copper foil (Cu), which shows a relatively smooth surface; Figure b is a SEM image of three-dimensional copper foil (3D Cu) after wet chemical treatment, showing a three-dimensional surface structure that provides more space for zinc deposition; Figure c is a SEM image of the material (Cu-Zn) after electroplating zinc onto ordinary copper foil, showing sharp dendrites with more dendrites in some areas and fewer in others, resulting in a very uneven distribution; Figure d is a SEM image of the material (3D Cu-Zn) after electroplating zinc onto three-dimensional copper foil, showing a coral-like dendrite structure with a relatively uniform distribution.

[0077] The XRD patterns of ordinary zinc foil (Zn), ordinary copper foil (Cu), the material after electroplating ordinary copper foil with zinc (Cu-Zn), the three-dimensional copper foil after wet chemical treatment (3D Cu), and the material after electroplating three-dimensional copper foil with zinc (3D Cu-Zn) are shown in Example 1. Figure 5As shown in the figure. Figure a shows the XRD patterns of Zn, Cu, and Cu-Zn; Figure b shows the XRD patterns of 3D Cu and 3D Cu-Zn. It can be seen that the characteristic peaks of the XRD pattern of Zn are consistent with those of the Cu standard PDF card (PDF#01-1241 Cu), indicating that the sample used has high purity and contains almost no other impurities; Cu-Zn has both Cu and Zn characteristic peaks, indicating that Zn was effectively electroplated on Cu. Figure b shows the XRD patterns of 3D Cu and 3D Cu-Zn. It can be seen that only two characteristic peaks of 3D Cu are retained, and the characteristic peaks of 3D Cu-Zn are consistent with those of the Zn standard PDF card (PDF#04-0831 Zn), with only (101), indicating that horizontal orientation growth of the (101) crystal plane was achieved.

[0078] A comparison of constant current charge-discharge of three types of Zn / / Zn symmetrical batteries—ordinary Zn, Cu-Zn, and 3D Cu-Zn—is shown in the figure below. Figure 6 As shown in Figure a. It can be seen from Figure a that at 5 mA / cm 2 At the specified current density, the 3D Cu-Zn symmetrical cell, acting as both positive and negative electrodes, exhibited more stable cycling and a lower polarization voltage, achieving stable cycling for 450 h. In contrast, the symmetrical cells of ordinary Zn and Cu-Zn short-circuited at 175 h and 144 h, respectively. Enlarged views of the cycling sections in figures b and c show that all three symmetrical cells cycled normally from 10 to 12 h without short-circuiting; the 3D Cu-Zn / / 3D Cu-Zn symmetrical cell continued to cycle normally from 448 h to 450 h without short-circuiting. As can be seen from figures d, e, and f, the 3D Cu-Zn / / 3D Cu-Zn symmetric cell has a low polarization voltage of 78.5 mV, which is not much different from the polarization voltage of the ordinary Zn symmetric cell. However, the polarization voltage of the ordinary Zn / / ordinary Zn symmetric cell is unstable, and the polarization voltage shows significant changes at 100, 200, and 300 cycles. Although the Cu-Zn / / Cu-Zn cell has a polarization voltage of 70.1 mV, its cycle stability is poor, and a short circuit has occurred after 144 hours.

[0079] The comparison chart of constant current charge and discharge of three types of Zn / / Cu half-cells—ordinary Zn / / Cu, Cu-Zn / / Cu, and 3D Cu-Zn / / Cu—is shown below. Figure 7As shown in Figure a, the 3D Cu-Zn / / Cu half-cell achieved ultra-stable cycling for over 450 cycles under these test conditions, exhibiting an average coulombic efficiency as high as 99.8%. Compared to the ordinary Zn / / Cu half-cell, the 3D Cu-Zn / / Cu half-cell showed more stable coulombic efficiency in the initial stage. However, starting from the 130th cycle, the coulombic efficiency of the Cu-Zn / / Cu half-cell began to fluctuate unstablely. Figures b, c, and d show the polarization voltages at 1, 50, and 100 cycles for the ordinary Zn / / Cu, Cu-Zn / / Cu, and 3D Cu-Zn / / Cu half-cells, respectively. It can be seen that the 3D Cu-Zn half-cell has a polarization voltage of 70.4 mV, lower than Cu-Zn's 148.9 mV and Zn's Zn / / Cu half-cell's 101.4 mV, indicating that the 3D Cu-Zn / / Cu half-cell has a lower polarization voltage.

[0080] Ordinary Zn / / (NH4) x VO3, Cu-Zn / / (NH4) x VO3 and 3D Cu-Zn / / (NH4) x VO3 contains these three types of Zn / (NH4) x The cycle performance comparison chart of VO3 full batteries is shown below. Figure 8 As shown in Figure a, ordinary Zn / / (NH4) x VO3, Cu-Zn / / (NH4) x VO3 and 3D Cu-Zn / / (NH4) x VO3 contains these three types of Zn / (NH4) x The constant current charge-discharge curves of the VO3 full cell at a current density of 5 A / g show that the battery initially reaches a capacity of over 250 mAh / g at this current density, and still maintains a capacity of over 160 mAh / g after 200 cycles, demonstrating a high capacity and indicating that 3D Cu-Zn exhibits slower capacity decay and a longer battery life. Figures b, c, and d show that the capacity curves (positive slope curves represent charging curves, showing the trend of charging capacity with voltage change, indicating a charging plateau; negative slope curves represent discharging curves, showing the trend of discharging capacity decreasing with voltage change, indicating a discharging plateau) indicate that in 3D Cu-Zn / / (NH4)... x In VO3 full cells, the polarization voltage is relatively small and the capacity plateau is flat, resulting in a higher degree of curve fit; the stable voltage curve plateau generally reflects the good compatibility of this positive and negative electrode and separator combination; compared with ordinary Zn / (NH4) x VO3, Cu-Zn / / (NH4) x Compared to VO3 full cells, 3D Cu-Zn / / (NH4) cells under the same number of revolutions... xThe VO3 full cell exhibits superior specific capacity. This indicates that using 3D Cu-Zn as the negative electrode in this embodiment can significantly improve the long-cycle stability of the zinc-ion battery.

[0081] 3D Cu-Zn / / (NH4) assembled using 3D 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 9 As shown in the figure, the oxidation peak potential is approximately 1.126 V, which corresponds to VO. x - The oxidation process; the reduction peak potential is approximately 0.840 V, corresponding to VO x - The reduction process was observed. The measured results showed symmetrical and sharp peaks, indicating that the 3D Cu-Zn anode has good reversibility.

[0082] Zn / / (NH4) assembled using 3D Cu-Zn as the negative electrode x Voltage and application testing of three stacked VO3 full-cell batteries, as follows: Figure 10 As shown in Figure a, three 3D Cu-Zn / / (NH4) atoms can be observed. x The voltage of the stacked VO3 full cells measured with a multimeter was 4.603 V. Figure b shows the stacked three 3D Cu-Zn / / (NH4) atoms. x VO3 fully powered LED light strip.

[0083] Example 2

[0084] The method for preparing the zinc anode sheet on the three-dimensional copper foil substrate provided in this embodiment is basically the same as that in Example 1; the difference lies in the assembled Zn / / Zn symmetric cell, Zn / / Cu half-cell, and Zn / / (NH4) cell. x The standard specification model of the VO3 full battery is 2032, and the negative and positive electrode shells selected are of model 2032; the gaskets are 1.0 mm thick and 0.5 mm thick.

[0085] Example 3

[0086] The method for preparing the zinc negative electrode sheet on the three-dimensional copper foil substrate provided in this embodiment is basically the same as that in Example 1; the difference is that the copper foil used is 5 cm long × 5 cm wide × 15 μm thick.

[0087] Example 4: Effect of different concentrations of ferric chloride etching solution on copper foil corrosion and obtaining a three-dimensional copper foil substrate

[0088] The preparation method of the zinc negative electrode sheet on the three-dimensional copper foil substrate provided in this embodiment is basically the same as that in Example 1; the difference is that: when preparing the etching solution, 4.055 g of FeCl3·6H2O is dissolved in 150 mL of deionized water; 12 mol / L concentrated hydrochloric acid is added dropwise until the pH value of the solution is 3.0, and the mixture is stirred for 30 min to completely dissolve all the ferric chloride hexahydrate, thus obtaining the etching solution. That is, the concentration of FeCl3 in the etching solution is 0.1 mol / L. A copper foil with a length of 10 cm × width of 10 cm × thickness of 15 μm is immersed in the etching solution and left to stand at room temperature for 2 h.

[0089] 3D Cu-Zn anode sheets prepared with etching solutions of different concentrations were used in the assembly of Zn / / Zn symmetric cells, Zn / / Cu half-cells, and Zn / / (NH4) cells. x The constant current charge and discharge comparison chart of the VO3 full battery is shown below. Figure 11 As shown in Figure a, the symmetrical cell comparison in Figure a shows that the 3D Cu-Zn / / 3D Cu-Zn symmetrical cell treated with low concentration for a long time exhibits less polarization and achieves ultra-stable cycling for 200 h; while the 3D Cu-Zn / / 3D Cu-Zn symmetrical cell treated with high concentration for a long time shows greater polarization. The half-cell polarization comparison in Figures b and c shows that the polarization voltages of the 3D Cu-Zn / / Cu half-cells under the two different treatment conditions are 70.5 mV and 70.0 mV, respectively, with almost identical capacity-voltage diagrams. Figure d shows that regardless of whether the 3D Cu-Zn / / (NH4) is treated with low concentration for a long time or high concentration for a short time, the polarization is consistent. x The VO3 full cell initially achieved capacities exceeding 100 mAh / g and 250 mAh / g at a current density of 5 A / g, respectively. After 200 cycles, the capacities still reached 63 mAh / g and 163 mAh / g, demonstrating high capacity. This also indicates that 3D Cu-Zn exhibits slower capacity decay and longer battery life. The high-concentration, short-time-treated 3D Cu-Zn full cell showed more stable coulombic efficiency, achieving an average coulombic efficiency of 99.8% over 1050 cycles, while the low-concentration, long-time-treated 3D Cu-Zn full cell still achieved a slightly lower coulombic efficiency of 99.7%.

[0090] 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 zinc negative electrode sheet with a three-dimensional copper foil substrate, characterized in that, Includes the following steps: Adjust the pH of the ferric chloride solution to no more than 3.0, then place the copper foil in the solution and allow it to undergo a corrosion reaction at room temperature. Zinc foil is used as the counter electrode, and etched copper foil is used as the working electrode. The two electrodes are then placed in an electroplating solution for electroplating to obtain a zinc negative electrode sheet with a three-dimensional copper foil substrate.

2. The method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate according to claim 1, characterized in that, The concentration of the ferric chloride is 0.1-3 mol / L, and the corrosion time is 10-120 min.

3. The method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate according to claim 2, characterized in that, When the concentration of the ferric chloride is 0.1 mol / L, the corrosion time is not less than 1 h; When the concentration of the ferric chloride is 0.3 mol / L, the corrosion time does not exceed 30 min.

4. The method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate according to claim 1, characterized in that, The pH of the ferric chloride solution was adjusted with hydrochloric acid.

5. The method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate according to claim 1, characterized in that, The electroplating conditions are 1-15 mA / cm. 2 Electroplating at current density for 30-120 min; Furthermore, the electroplating conditions were 10 mA / cm². 2 Electroplating was performed at a current density for 60 minutes.

6. The method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate according to claim 1, characterized in that, The electroplating solution comprises sodium sulfate and zinc sulfate.

7. The method for preparing a zinc negative electrode sheet with a three-dimensional copper foil substrate according to claim 6, characterized in that, In the electroplating solution, the concentration of sodium sulfate is 0.15-0.5 mol / L, and the concentration of zinc sulfate is 0.05-0.6 mol / L; Furthermore, in the electroplating solution, the concentration of sodium sulfate is 0.25 mol / L and the concentration of zinc sulfate is 0.3 mol / L.

8. A zinc negative electrode sheet having a three-dimensional copper foil substrate, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

9. The zinc anode sheet with a three-dimensional copper foil substrate prepared by the preparation method according to any one of claims 1-7, or the zinc anode sheet with a three-dimensional copper foil substrate according to claim 8, is used in the preparation of an aqueous zinc-ion battery.

10. An aqueous zinc-ion battery, characterized in that, The aqueous zinc-ion battery includes a zinc anode sheet with a three-dimensional copper foil substrate prepared by the preparation method according to any one of claims 1-7, or a zinc anode sheet with a three-dimensional copper foil substrate as described in claim 8.

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