Method for preparing copper-zinc composite zinc negative electrode based on polyglutamic acid-chloride electroplating solution

Abstract

The invention provides a method for preparing a copper-zinc composite zinc negative electrode based on a polyglutamic acid-chloride electroplating solution, and belongs to the technical field of zinc ion batteries. A mixed high-entropy electroplating solution containing zinc salt, sodium salt, polyglutamic acid, chlorine salt and a solvent is prepared, a copper foil serves as a working electrode, a zinc sheet serves as a counter electrode, the copper foil and the zinc sheet are placed in the mixed high-entropy electroplating solution for electroplating, and the copper-zinc composite zinc negative electrode is obtained. Through the synergistic effect between the polyglutamic acid and the chlorine salt, uniform deposition of zinc ions is promoted, the stability of the plating solution is enhanced, impurity interference is reduced, the defect generation probability of a plating layer is reduced, the electroplating effect can be guaranteed under complex working conditions, and the performance and quality of electroplated products are comprehensively improved; further, the safety, the cycle life and the electrochemical performance of the aqueous zinc ion battery are comprehensively improved from multiple aspects of inhibiting dendritic crystals, stabilizing an interface and the like, and the method has a good practical application prospect.

Description

Technical Field

[0001] This invention relates to the field of zinc-ion battery technology, and specifically to a method for preparing a copper-zinc composite zinc anode based on a polyglutamic acid-chloride electroplating solution. Background Technology

[0002] As global demand for sustainable energy solutions continues to grow, the development of new battery technologies is becoming increasingly important. While traditional lithium-ion batteries have achieved great success in areas such as portable electronic devices and electric vehicles, the scarcity and cost of lithium resources, as well as the flammability and environmental unfriendliness of organic electrolytes, limit their large-scale application.

[0003] Aqueous zinc-ion batteries (AZIBs) have attracted widespread attention in recent years as a promising alternative. Using zinc metal as the negative electrode and an aqueous electrolyte, they offer several significant advantages. First, zinc is abundant and widely distributed on Earth, with relatively low cost, giving aqueous zinc-ion batteries a clear cost advantage for large-scale applications. Second, zinc metal has a high theoretical specific capacity. Furthermore, the aqueous electrolyte uses water as a solvent, avoiding the flammable and explosive safety hazards of organic electrolytes, resulting in higher safety and environmental friendliness, aligning with the principles of sustainable development.

[0004] However, despite the promising prospects of aqueous zinc-ion batteries, their practical application still faces many challenges. In aqueous electrolytes, a series of side reactions occur at the zinc anode, with the hydrogen evolution reaction being particularly prominent. This is because water molecules in the zinc anode... 2+ During desolvation, the reaction leads to hydrogen evolution, which not only reduces the battery's coulombic efficiency but also damages electrode materials and degrades battery performance. Furthermore, zinc dendrite growth is a serious problem; during charge and discharge, Zn... 2+ Uneven deposition can lead to the formation of zinc dendrites. As the number of cycles increases, zinc dendrites may puncture the separator, causing a short circuit in the battery and potentially leading to a safety accident.

[0005] Therefore, copper, with its good conductivity and strength, is usually used as the substrate when manufacturing zinc anodes. However, current copper foil zinc plating technology still has many shortcomings in practical applications: under traditional electroplating solution formulations, the zinc coating is prone to poor uniformity, pinholes, or porosity, affecting the corrosion resistance and surface smoothness of the copper foil; some processes rely on toxic additives such as cyanide, which not only threaten the operating environment and personnel health, but also increase the difficulty and cost of wastewater treatment; zinc ions are prone to dendrite growth due to uneven concentration distribution during deposition, reducing the adhesion between the coating and the copper foil substrate, and may cause peeling and blistering problems during long-term use; in addition, existing processes are difficult to balance between improving current efficiency, shortening electroplating time, and ensuring coating quality, and some high-stability formulations have problems such as high additive costs and difficulty in recycling, making it difficult to fully meet the needs of environmentally friendly, efficient, and low-cost industrial production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing a copper-zinc composite zinc anode based on a polyglutamic acid-chloride electroplating solution. This invention introduces chloride and polyglutamic acid additives into the electroplating solution. Through the coordination interaction between the carboxyl groups in the polyglutamic acid molecules and zinc ions, a stable adsorption layer is formed on the surface of the zinc anode, effectively limiting the zinc content. 2+ The disordered diffusion inhibits the growth of zinc dendrites and their penetration of the diaphragm; simultaneously, the chloride ions (Cl-) generated by the dissociation of chlorides (e.g., zinc chloride, potassium chloride, sodium chloride, etc.) - It can not only enhance the conductivity of the electrolyte and reduce the internal resistance of the battery, but also optimize the dynamics of the positive and negative electrode interfaces by activating the zinc ion deposition process and inhibiting the dissolution of the positive electrode active material.

[0007] To achieve the above objectives, the specific technical solution of the present invention is as follows:

[0008] In a first aspect, the present invention provides a mixed high-entropy electroplating solution for preparing copper-zinc composite zinc anodes, comprising zinc salt, sodium salt, additives and solvent, wherein the additives include polyglutamic acid (PGA) and chloride salt.

[0009] Furthermore, the mass ratio of the polyglutamic acid to the chloride salt is (1-2):(1-2).

[0010] Furthermore, the mass concentration of polyglutamic acid and chloride salt in the mixed high-entropy electroplating solution is 0.01%-0.05%.

[0011] Furthermore, the chloride salt includes, but is not limited to, at least one of zinc chloride, potassium chloride, and sodium chloride.

[0012] Further, the concentration of the zinc salt is 0.2-0.3 mol / L, and the concentration of the sodium salt is 0.2-0.3 mol / L.

[0013] Furthermore, the zinc salt includes, but is not limited to, at least one of zinc sulfate, zinc nitrate, and zinc acetate, and the sodium salt includes, but is not limited to, at least one of sodium sulfate, sodium carbonate, and sodium acetate.

[0014] Secondly, the present invention provides a method for preparing the mixed high-entropy electroplating solution for preparing copper-zinc composite zinc anode, comprising the following steps: mixing zinc salt, sodium salt, polyglutamic acid and chloride salt in water to obtain a mixed high-entropy electroplating solution with polyglutamic acid and chloride salt as additives.

[0015] Thirdly, the present invention provides a method for preparing a copper-zinc composite zinc anode using the aforementioned mixed high-entropy electroplating solution, comprising the following steps: preparing the mixed high-entropy electroplating solution; and electroplating a copper foil as the working electrode and a zinc sheet as the counter electrode in the mixed high-entropy electroplating solution to obtain a copper-zinc composite zinc anode. During copper electroplating with zinc, polyglutamic acid and chloride salts are added to a conventional electroplating solution containing zinc salts (e.g., zinc sulfate) and sodium salts (e.g., sodium sulfate), which synergistically enhance the electroplating effect. Specifically, chloride salts can enhance the conductivity of the plating solution and reduce internal resistance through Cl⁻ to achieve uniform current distribution, while simultaneously stabilizing Zn. 2+ It also complexes impurity ions, optimizing the electrochemical environment of the plating bath; polyglutamic acid, as an organic additive, slows down the degradation of Zn by adsorbing onto highly active regions of the substrate. 2+ The reduction rate forces Zn 2+ Uniform nucleation refines grain size and improves coating growth morphology. The combination of these two methods provides a stable environment for coating control and overcomes the roughness inherent in purely inorganic plating solutions, ultimately resulting in a uniform, dense, strongly bonded, and aesthetically pleasing zinc coating. This invention utilizes the synergistic effect of polyglutamic acid and chloride salts to regulate uniform zinc ion deposition, resulting in a homogeneous zinc coating. This comprehensively improves the safety, cycle life, and electrochemical performance of aqueous zinc-ion batteries by inhibiting dendrite formation and stabilizing the interface, demonstrating promising practical application prospects.

[0016] Furthermore, the current during the electroplating process is 5-20 mA·cm. -2 The electroplating time is 0.5-1.5 h.

[0017] Fourthly, the present invention provides a copper-zinc composite zinc anode prepared by the method described above.

[0018] Fifthly, the present invention provides the application of the copper-zinc composite zinc anode in the preparation of aqueous zinc-ion batteries.

[0019] In a sixth aspect, the present invention provides an aqueous zinc-ion battery, comprising the copper-zinc composite zinc negative electrode.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] This invention uses polyglutamic acid and chloride salts as additives. Polyglutamic acid, with its numerous carboxyl groups, can complex with metal ions, promoting uniform deposition of zinc ions on the coating surface. This results in a uniform and dense coating, effectively improving its smoothness and gloss, and overcoming the problems of uneven zinc coating thickness and numerous pinholes in existing technologies. Furthermore, polyglutamic acid, as a green and environmentally friendly biopolymer, is non-toxic and biodegradable, avoiding the environmental pollution and health risks associated with traditional toxic additives, ensuring production safety from the source. Chloride salts (such as zinc chloride) not only provide zinc ions but also increase the conductivity of the plating solution. Increasing its content within a certain range can raise the upper limit of allowable current density, accelerate deposition speed, shorten electroplating time, and improve production efficiency. This invention, through the synergistic effect between polyglutamic acid and chloride salts, promotes uniform zinc ion deposition, enhances plating solution stability, reduces impurity interference, lowers the probability of coating defects, and ensures electroplating effects even under complex working conditions, comprehensively improving the performance and quality of electroplated products. Attached Figure Description

[0022] Figure 1 The XRD patterns of pure copper foil, pure zinc sheet, Cu@Zn, and PGA-ZC-Cu@Zn in Example 1 are shown below.

[0023] Figure 2 The image shows a SEM image of the zinc negative electrode; where, Figure 2 a is a SEM image of the zinc negative electrode obtained by electroplating in a common electroplating solution; Figure 2 b is a SEM image of the zinc anode obtained by electroplating in an electroplating solution with added polyglutamic acid; Figure 2 c is a SEM image of the zinc anode obtained by electroplating in a mixed high-entropy electroplating solution with added polyglutamic acid and zinc chloride; Figure 2 d is a SEM image of the zinc anode obtained by electroplating in a mixed high-entropy electroplating solution with added polyglutamic acid and zinc chloride, used as a Zn / / Zn simulated battery;

[0024] Figure 3 The results of constant current charge-discharge tests for PGA-ZC-Cu@Zn, PGA-Cu@Zn, and ordinary Zn / / Zn symmetric cells in Example 1 are shown; among them, Figure 3 a represents the cycle test results of PGA-ZC-Cu@Zn, PGA-Cu@Zn, and ordinary Zn / / Zn symmetric cells; Figure 3 b represents the charge-discharge curves of a PGA-ZC-Cu@Zn symmetrical battery with different number of cycles; Figure 3 c represents the charge-discharge curves of the PGA-Cu@Zn symmetrical battery at different cycles; Figure 3 Figure d shows the charge-discharge curves of a typical Zn / / Zn symmetrical battery with different numbers of cycles;

[0025] Figure 4The results of constant current charge-discharge tests for the PGA-ZC-Cu@Zn / / Cu half-cell and the PGA-Cu@Zn / / Cu half-cell in Example 1 are shown; where, Figure 4 a represents the cycle test results of the PGA-ZC-Cu@Zn / / Cu half-cell and the PGA-Cu@Zn / / Cu half-cell; Figure 4 b represents the charge-discharge curves of the PGA-ZC-Cu@Zn / / Cu half-cell at different cycles; Figure 4 c represents the charge-discharge curves of the PGA-Cu@Zn / / Cu half-cell at different cycles;

[0026] Figure 5 This is a comparison chart of the cycle performance of the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell and the PGA-Cu@Zn / / (NH4)xVO3 full cell in Example 1; where, Figure 5 a is the discharge specific capacity efficiency cycle diagram of the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell and the PGA-Cu@Zn / / (NH4)xVO3 full cell; Figure 5 b represents the charge-discharge curves of the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell at different cycle counts; Figure 5 c represents the charge-discharge curves of the PGA-Cu@Zn / / (NH4)xVO3 full cell at different cycle counts;

[0027] Figure 6 The results are the CV test results of the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell in Example 1;

[0028] Figure 7 In the 'a' group, there are 3 PGA-ZC-Cu@Zn / / (NH4) x The voltage value of a VO3 full-cell series connection. Figure 7 In the middle, b represents 3 PGA-ZC-Cu@Zn / / (NH4) x VO3 full battery connected in series to light up LEDs;

[0029] Figure 8 The images show physical samples of PGA-ZC-Cu@Zn and PGA-Cu@Zn. Detailed Implementation

[0030] 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.

[0031] This invention provides a mixed high-entropy electroplating solution for preparing copper-zinc composite zinc anodes, comprising zinc salt, sodium salt, additives and solvent, wherein the additives include polyglutamic acid (PGA) and chloride salts.

[0032] In some examples, the mass ratio of the polyglutamic acid to the chloride salt is (1-2):(1-2).

[0033] In some examples, the mass concentration of polyglutamic acid and chloride salt in the mixed high-entropy electroplating solution is 0.01%-0.05%.

[0034] In some examples, the chloride salt includes, but is not limited to, at least one of zinc chloride, potassium chloride, and sodium chloride; the zinc salt includes, but is not limited to, at least one of zinc sulfate, zinc nitrate, and zinc acetate; and the sodium salt includes, but is not limited to, at least one of sodium sulfate, sodium carbonate, and sodium acetate.

[0035] In some examples, the concentration of the zinc salt is 0.2-0.3 mol / L, and the concentration of the sodium salt is 0.2-0.3 mol / L.

[0036] The method for preparing the mixed high-entropy electroplating solution for preparing copper-zinc composite zinc anode includes the following steps: mixing zinc salt, sodium salt, polyglutamic acid and chloride salt in water to obtain a mixed high-entropy electroplating solution with polyglutamic acid and chloride salt as additives.

[0037] The method for preparing a copper-zinc composite zinc anode using the aforementioned mixed high-entropy electroplating solution includes the following steps: preparing the mixed high-entropy electroplating solution; placing a copper foil as the working electrode and a zinc sheet as the counter electrode in the mixed high-entropy electroplating solution for electroplating to obtain a copper-zinc composite zinc anode.

[0038] In some examples, the current for the electroplating process is 5-20 mA·cm. -2 The electroplating time is 0.5-1.5 h.

[0039] Example 1

[0040] An aqueous zinc-ion battery is prepared as follows:

[0041] (1) Preparation of electroplating solution:

[0042] 1) Weigh 5.76 g ZnSO4·7H2O and 2.83 g NaSO4 into a beaker, make up to 80 mL with deionized water, and stir for 0.5 h at room temperature to obtain a common electroplating solution.

[0043] 2) Weigh 5.76 g ZnSO4·7H2O and 2.83 g NaSO4 into a beaker, add polyglutamic acid, and dilute to 80 mL with deionized water to make the mass concentration of polyglutamic acid 0.05%; stir at room temperature for 0.5 h to obtain an electroplating solution with added polyglutamic acid.

[0044] 3) Weigh 5.76 g ZnSO4·7H2O and 2.83 g NaSO4 into a beaker, and continue to add polyglutamic acid (PGA) and zinc chloride (ZC). Make up the volume to 80 mL with deionized water so that the mass concentration of polyglutamic acid is 0.05% and the mass concentration of zinc chloride is 0.05%. Stir at room temperature for 0.5 h to obtain a mixed high-entropy electroplating solution with added polyglutamic acid and zinc chloride.

[0045] (2) Copper-zinc composite zinc anode:

[0046] 1) Using copper foil (Cu) as the working electrode and zinc sheet (Zn) as the counter electrode, the electrode is placed in a common electroplating solution at a temperature of 25℃ and a current of 8 mA·cm. -2 Electroplating was performed for 1 hour under the specified conditions. After electroplating, the electrode was repeatedly rinsed with deionized water and dried to obtain a copper-zinc composite zinc anode, denoted as Cu@Zn. The anode was then die-cut to a diameter of 12 mm for later use.

[0047] 2) Using copper foil (Cu) as the working electrode and zinc sheet (Zn) as the counter electrode, the electrode was placed in an electroplating solution containing polyglutamic acid, at a current of 8 mA·cm⁻¹. -2 Electroplating was performed for 1 hour under the specified conditions. After electroplating, the electrode was repeatedly rinsed with deionized water and dried to obtain a copper-zinc composite zinc anode, denoted as PGA-Cu@Zn (see physical image). Figure 8 Stamp the sheet to a diameter of 12 mm and set aside.

[0048] 3) Using copper foil (Cu) as the working electrode and zinc sheet (Zn) as the counter electrode, the electrode was placed in a mixed high-entropy electroplating solution containing polyglutamic acid and zinc chloride, at a current of 8 mA·cm⁻¹. -2 Electroplating was performed for 1 hour under the specified conditions. After electroplating, the electrode was repeatedly rinsed with deionized water and dried to obtain a copper-zinc composite zinc anode, denoted as PGA-ZC-Cu@Zn (see physical image). Figure 8 Stamp the sheet to a diameter of 12 mm and set aside.

[0049] (3) Negative electrode material testing:

[0050] The copper-zinc composite zinc anode material prepared in step (2) was subjected to XRD and SEM tests. The XRD patterns of pure Cu, pure Zn, Cu@Zn, and PGA-ZC-Cu@Zn are shown below. Figure 1As shown, the peak intensity ratio of I(101) / I(002) in PGA-ZC-Cu@Zn is 1.99, while that in Cu@Zn is 1.15. This indicates that the (101) crystal plane has a larger proportion in PGA-ZC-Cu@Zn, while the (002) crystal plane has a larger proportion in ordinary Cu@Zn. Furthermore, the XRD patterns of pure Zn and pure Cu are consistent with the standard PDF card, indicating that the samples are clean, free of interfering substances, and have high purity. The characteristic peaks of PGA-ZC-Cu@Zn are consistent with those of pure Zn and pure Cu, indicating that it uses Zn as a substrate and that Cu atom doping was successful. In addition, the peak values ​​are significantly higher than those of Cu@Zn, indicating a more ideal electroplating effect. SEM images of Cu@Zn, PGA-Cu@Zn, PGA-ZC-Cu@Zn, and PGA-ZC-Cu@Zn used in Zn / / Zn simulated batteries are shown below. Figure 2 As shown, compared to Cu@Zn and PGA-Cu@Zn, the zinc surface has a large number of pits, which is not conducive to zinc ion deposition. The zinc surface of PGA-ZC-Cu@Zn is smoother, which makes the local charge distribution more uniform, induces uniform zinc ion deposition, effectively inhibits the growth of zinc dendrites, significantly improves the cycle life of the battery, and exhibits superior performance.

[0051] (4) Assembly of aqueous zinc-ion batteries:

[0052] Assemble the negative electrode shell, negative electrode sheet, separator, ZnSO4 electrolyte, positive electrode sheet, gasket, spring sheet, and positive electrode shell in sequence, and then place the battery into a battery assembly device for sealing.

[0053] 1) When the negative electrode and the positive electrode are the same, a symmetrical cell is obtained by assembly. Specifically, by assembling with PGA-ZC-Cu@Zn as the negative electrode and the positive electrode, PGA-Cu@Zn as the negative electrode and the positive electrode, and pure zinc sheet as the negative electrode and the positive electrode, respectively, a PGA-ZC-Cu@Zn symmetrical cell, a PGA-Cu@Zn symmetrical cell, and a regular Zn / / Zn symmetrical cell can be obtained.

[0054] 2) Using a copper sheet with a diameter of 12 mm as the positive electrode, and PGA-ZC-Cu@Zn and PGA-Cu@Zn as the negative electrode, respectively, PGA-ZC-Cu@Zn / / Cu half-cells and PGA-Cu@Zn / / Cu half-cells can be assembled respectively.

[0055] 3) Using (NH4)xVO3 as the positive electrode and PGA-ZC-Cu@Zn and PGA-Cu@Zn as the negative electrode, respectively, PGA-ZC-Cu@Zn / / (NH4)xVO3 full cells and PGA-Cu@Zn / / (NH4)xVO3 full cells can be assembled. The preparation method of (NH4)xVO3 electrode is as follows: ammonium vanadate, acetylene black, and polyvinylidene fluoride are mixed in a mass ratio of 7:2:1. NMP is added and the mixture is ground to obtain a uniform positive electrode slurry. After coating the slurry onto carbon paper and drying it in an oven, it is punched to a diameter of 12 mm to obtain the (NH4)xVO3 electrode.

[0056] (5) Performance testing of aqueous zinc-ion batteries

[0057] 1) The PGA-ZC-Cu@Zn, PGA-Cu@Zn, and ordinary Zn / / Zn symmetric cells assembled in step (4) were tested on the Blue Electricity Test System: at 5 mA·cm -2 Current density, 1 mAh·cm -2 Under specific capacity conditions, constant current charge-discharge tests were conducted, following the sequence of rest, constant current discharge, rest, constant current charge, and cycling. The rest period was 30 seconds for each cycle, and the constant current charge-discharge time was 0.2 hours. The test results are as follows: Figure 3 As shown, where, Figure 3 a represents the cycle test results of PGA-ZC-Cu@Zn, PGA-Cu@Zn, and ordinary Zn / / Zn symmetric cells; Figure 3 b represents the charge-discharge curves of a PGA-ZC-Cu@Zn symmetrical battery with different number of cycles; Figure 3 c represents the charge-discharge curves of the PGA-Cu@Zn symmetrical battery at different cycles; Figure 3 d represents the charge-discharge curves of a typical Zn / / Zn symmetrical battery with different numbers of cycles. Figure 3 It can be seen that the cycle stability of the PGA-ZC-Cu@Zn symmetric battery prepared by the present invention is significantly stronger than that of the ordinary Zn / / Zn symmetric battery, and the polarization voltage (60 mV) of the PGA-ZC-Cu@Zn symmetric battery is significantly lower than that of the PGA-Cu@Zn symmetric battery (78 mV) and the ordinary Zn / / Zn symmetric battery (99 mV).

[0058] 2) The PGA-ZC-Cu@Zn / / Cu half-cell and the PGA-Cu@Zn / / Cu half-cell assembled in step (4) were tested on the Blue Electricity Test System: at 5 mA·cm -2 Current density, 1 mAh·cm -2Under specific capacity conditions, constant current charge-discharge tests were conducted, following the sequence of rest, constant current discharge, rest, constant current charge, and cycling. The rest period was 30 seconds for each cycle, and the constant current charge-discharge time was 0.2 hours. The test results are as follows: Figure 4 As shown, where, Figure 4 a represents the cycle test results of the PGA-ZC-Cu@Zn / / Cu half-cell and the PGA-Cu@Zn / / Cu half-cell; Figure 4 b represents the charge-discharge curves of the PGA-ZC-Cu@Zn / / Cu half-cell at different cycles; Figure 4 c represents the charge-discharge curves of the PGA-Cu@Zn / / Cu half-cell at different cycle counts. Figure 4 It can be seen that the PGA-ZC-Cu@Zn / / Cu half-cell prepared by the present invention has a slightly higher coulombic efficiency than the PGA-Cu@Zn / / Cu half-cell, and has a significantly lower polarization voltage (60 mV).

[0059] 3) The PGA-ZC-Cu@Zn / / (NH4)xVO3 full cells assembled in step (4) and the PGA-Cu@Zn / / (NH4)xVO3 full cells were tested on the Blue Electric System. The test results are as follows: Figure 5 As shown, where, Figure 5 a is the discharge specific capacity efficiency cycle diagram of the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell and the PGA-Cu@Zn / / (NH4)xVO3 full cell; Figure 5 b represents the charge-discharge curves of the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell at different cycle counts; Figure 5 c represents the charge-discharge curves of the PGA-Cu@Zn / / (NH4)xVO3 full cell at different cycle numbers. Figure 5 It can be seen that the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell prepared by the present invention has a significantly higher specific capacity and its specific capacity decay rate is lower than that of the PGA-Cu@Zn / / (NH4)xVO3 full cell.

[0060] CV tests were performed on the PGA-ZC-Cu@Zn / / (NH4)xVO3 full cell, with scan rates ranging from 1 to 10 mV / s. The results were obtained from scans 1, 3, 5, 7, and 9. Figure 6 As shown. By Figure 6 It can be seen that the potential of the oxidation peak is approximately 1.182 V, which corresponds to VO3. - The oxidation process; the reduction peak potential is approximately 0.851 V, corresponding to VO3. - The reduction process; the measured results show that the peak shape is symmetrical and sharp, indicating that the electrode has good reversibility.

[0061] The voltage values ​​of three PGA-ZC-Cu@Zn / / (NH4)xVO3 full cells were measured in series. The results are shown below. Figure 7 a. The voltage value is displayed as 4.225 V; three PGA-ZC-Cu@Zn / / (NH4)xVO3 full cells are connected in series and an LED light is lit, and the result is as follows. Figure 7 As shown in b.

[0062] Example 2

[0063] The copper-zinc composite zinc anode prepared in this embodiment based on polyglutamic acid-chloride electroplating solution is prepared in the same steps as steps (1)-(2) in Example 1, except that the electroplating temperature is changed from 25℃ to 20℃. Testing showed that the zinc anode prepared in this embodiment has a smooth surface, which can induce uniform deposition of zinc ions and effectively inhibit the growth of zinc dendrites, thereby significantly improving the cycle life of the battery.

[0064] Example 3

[0065] The copper-zinc composite zinc anode prepared in this embodiment based on polyglutamic acid-chloride electroplating solution is prepared in the same steps as steps (1)-(2) in Example 1, except that the stirring time is changed from 0.5 h to 1 h when preparing the electroplating solution. Testing showed that the zinc anode prepared in this embodiment has a smooth surface, which can induce uniform zinc ion deposition and effectively inhibit the growth of zinc dendrites, thereby significantly improving the cycle life of the battery.

[0066] In summary, this invention prepares a mixed high-entropy electroplating solution comprising zinc salt, sodium salt, polyglutamic acid, chloride salt, and solvent, and electroplats copper foil as the working electrode and zinc sheet as the counter electrode in the mixed high-entropy electroplating solution to obtain a copper-zinc composite zinc anode. This invention promotes uniform zinc ion deposition, enhances solution stability, reduces impurity interference, and lowers the probability of coating defects through the synergistic effect between polyglutamic acid and chloride salt. It ensures electroplating effectiveness even under complex operating conditions, comprehensively improving the performance and quality of electroplated products. Furthermore, it comprehensively enhances the safety, cycle life, and electrochemical performance of aqueous zinc-ion batteries from multiple aspects, including suppressing dendrite formation and stabilizing the interface, demonstrating promising practical application prospects.

[0067] 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 mixed high-entropy electroplating solution for preparing a copper-zinc composite zinc negative electrode, characterized in that, The zinc salt, the sodium salt, the additive and the solvent, wherein the additive comprises polyglutamic acid and a chlorine salt.

2. The mixed high-entropy electroplating solution for preparing a copper-zinc composite zinc negative electrode according to claim 1, characterized by, The mass ratio of the polyglutamic acid and the chlorine salt is (1-2):(1-2). 3.The mixed high-entropy electroplating solution for preparing a copper-zinc composite zinc negative electrode according to claim 2, characterized in that, Further, the mass concentration of the polyglutamic acid in the mixed high-entropy electroplating solution is 0.01%-0.05%, and the mass concentration of the chlorine salt is 0.01%-0.05%. 4.The mixed high-entropy electroplating solution for preparing a copper-zinc composite zinc negative electrode according to claim 1, characterized in that, The concentration of the zinc salt is 0.2-0.3 mol / L, and the concentration of the sodium salt is 0.2-0.3 mol / L.

5. The method for preparing a mixed high-entropy plating solution for preparing a copper-zinc composite zinc negative electrode according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: mixing the zinc salt, the sodium salt, the polyglutamic acid and the chlorine salt in water to obtain a mixed high-entropy electroplating solution with the polyglutamic acid and the chlorine salt as additives.

6. The method of claim 1-4 for preparing copper-zinc composite zinc negative electrode using the mixed high-entropy electroplating solution, characterized in that, The method comprises the following steps: preparing the mixed high-entropy electroplating solution according to any one of claims 1-4; and electroplating in the mixed high-entropy electroplating solution with a copper foil as a working electrode and a zinc sheet as a counter electrode to obtain a copper-zinc composite zinc negative electrode.

7. The method of producing a copper-zinc composite zinc negative electrode according to claim 6, characterized by, The current of the electroplating process is 5-20 mA-cm -2 and the electroplating time is 0.5-1.5 h.

8. The copper-zinc composite zinc negative electrode prepared by the method of claim 6.

9. The use of the copper-zinc composite zinc negative electrode of claim 8 in the preparation of a water-based zinc ion battery.

10. An aqueous zinc-ion battery, characterized in that, The copper-zinc composite zinc negative electrode of claim 8.

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