Modified aqueous zinc battery negative electrode and preparation method thereof

Abstract

The invention belongs to the technical field of batteries, and discloses a modified aqueous zinc battery negative electrode and a preparation method thereof. The method comprises the following specific steps: S1, dissolving zinc sulfate heptahydrate in water to obtain a zinc sulfate solution; s2, adding water to dissolve pyridoxal phosphate to obtain a pyridoxal phosphate solution; the pretreated zinc foil is fully soaked in a pyridoxal phosphate solution and recorded as P (at) Z, and after soaking is completed, washing and drying are conducted for use; and S3, assembling a symmetric battery and a total battery by taking the P (at) Z as an electrode, a glass fiber filter membrane as a diaphragm and a zinc sulfate solution as an electrolyte. The problems of corrosion of zinc to the negative electrode, hydrogen evolution reaction, dendritic crystal growth and the like are effectively inhibited, and the capacity of prolonging the cycle life of the zinc negative electrode is achieved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a modified aqueous zinc battery anode and its preparation method. Background Technology

[0002] With the acceleration of global industrialization and continuous population growth, the excessive consumption of traditional fossil fuels and the resulting environmental pollution and climate change problems are becoming increasingly serious. Energy structure transformation has become a core issue for achieving sustainable development. Against this backdrop, the development of efficient and clean new energy storage technologies is particularly important. Electrochemical energy storage systems, as a key component of the new energy system, with battery technology, has been deeply integrated into electronic devices, power tools, new energy vehicles, and smart grid peak shaving due to its high energy conversion efficiency and flexible application scenarios.

[0003] However, traditional rechargeable battery systems based on organic electrolytes generally suffer from high cost, insufficient intrinsic safety, and poor environmental compatibility, limiting their large-scale application. In contrast, aqueous zinc-ion batteries (AZIBs) are considered strong contenders for next-generation large-scale energy storage systems due to their high safety, low cost, environmental friendliness, and the abundance of zinc resources. However, their commercialization is severely hampered by the instability of the zinc anode interface, mainly manifested in problems such as zinc dendrite formation, hydrogen evolution reaction (HER), corrosion, and surface passivation. These side reactions not only reduce coulombic efficiency but also lead to short cycle life and potential hazards. Therefore, anode modification has become a core research direction for improving the performance of aqueous zinc batteries.

[0004] Current mainstream anode modification strategies mainly include interface protection layer construction, three-dimensional structure design, electrolyte engineering, and alloying. In terms of interface engineering, constructing an artificial solid electrolyte interface (SEI) on the zinc anode surface can effectively isolate the active zinc from direct contact with the electrolyte, suppressing water-induced side reactions and hydrogen evolution corrosion. For example, dense coatings formed using organic polymers or inorganic nanomaterials can modulate Zn... 2+ The uniform deposition behavior reduces local current concentration, thereby alleviating dendrite formation. In addition, functional molecules with specific functional groups (such as polyfuranol) can form a stable SEI film on the zinc surface through in-situ polymerization. Experiments have shown that such modifications can significantly improve the cycle stability of symmetric cells by hundreds of hours or more.

[0005] Electrolyte additive regulation is another important approach. By introducing functional molecules (such as zwitterions or polar molecules like betaine and maltitol) into the electrolyte, they can preferentially adsorb at the electrode-electrolyte interface, modulating the inner Helmholtz layer (IHP) structure, repelling water molecules from approaching the zinc surface, thereby inhibiting HER and guiding planar deposition of Zn. Studies have shown that proper selection of additives can achieve coulombic efficiencies as high as 99.5%. However, the easy consumption and insufficient long-term stability of additives remain technical bottlenecks.

[0006] Overall, while significant progress has been made in existing technologies, common defects still exist: the protective layer has insufficient mechanical strength and is prone to cracking; the three-dimensional structure is costly and complex to manufacture; the additives have poor long-term effectiveness; and alloying may sacrifice capacity.

[0007] Therefore, providing a novel method for modifying the negative electrode is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0008] In view of this, the present invention provides a modified aqueous zinc battery anode and its preparation method. The method employs pyridoxal phosphate immersion of the anode to guide uniform zinc ion deposition. This process selectively removes high-energy crystal planes and depassivates the surface, expanding the active surface area, enhancing kinetics, and homogenizing the electric field to guide a uniform Zn ion flux. Simultaneously, the thermodynamically stable (002) plane is preferentially exposed, guiding Zn deposition along the (002) orientation and suppressing dendrite nucleation and growth. This effectively suppresses problems such as zinc corrosion of the anode, hydrogen evolution reaction, and dendrite growth. Experimental verification has shown that the selected selective etching strategy indeed has the ability to improve the cycle life of the zinc anode.

[0009] One objective of this invention is to provide a method for preparing a modified aqueous zinc battery anode, the specific steps of which are as follows:

[0010] S1: Electrolyte preparation Dissolve zinc sulfate heptahydrate in water to obtain a zinc sulfate solution; S2: Preparation of negative electrode Pyridoxal phosphate (PLP) is dissolved in water and stirred until fully dissolved to obtain a pyridoxal phosphate (PLP) solution. The pretreated zinc foil is fully immersed in the pyridoxal phosphate (PLP) solution, denoted as P@Z. After immersion, the zinc foil is removed, rinsed with alcohol, and dried for later use. S3: Battery Assembly Using P@Z as the negative electrode, a glass fiber filter membrane as the separator, and zinc sulfate solution as the electrolyte, a symmetrical cell and a full cell are assembled.

[0011] Furthermore, the positive and negative electrodes of the symmetrical battery both use P@Z, while the full battery only uses P@Z on the negative electrode.

[0012] Preferably, the concentration of the zinc sulfate solution is 1 mol / L.

[0013] Preferably, the concentration of the pyridoxal phosphate solution is 2-5 g / L, more preferably 5 g / mL.

[0014] Preferably, the pretreatment involves ultrasonically cleaning the zinc foil in anhydrous ethanol for 20 minutes.

[0015] Preferably, the soaking time is 1-24 hours, and more preferably 12 hours.

[0016] Preferably, the symmetrical battery and the full battery are of model CR2032.

[0017] The second objective of this invention is to provide a modified aqueous zinc battery negative electrode.

[0018] As can be seen from the above technical solution, compared with the prior art, the beneficial effects achieved by the present invention include: 1. This invention is the first to use pyridoxal phosphate (PLP) for modification treatment in the field of aqueous batteries; 2. This invention uses an immersion method to selectively etch the negative electrode surface, and the optimal solution is obtained by comparing different immersion time groups; 3. Unlike the lithium-sodium batteries currently in widespread use, this invention uses zinc as the battery negative electrode. my country has high zinc reserves, which can greatly reduce the cost of battery negative electrodes. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 Example 1 (Zn‖Zn symmetric cell) was tested under conditions of 2.0 mA cm⁻¹. -2 2.0mAh cm -2 SEM image of the zinc anode surface after 25 cycles; Figure 2 This is a long-cycle test diagram of the zinc symmetric cell in Example 1; Figure 3 Example 2 (Zn‖MnO2 full cell) under the condition of 1 A g -1 hour SEM image of the zinc anode surface after 25 cycles; Figure 4 The discharge specific capacity diagram of the zinc full cell in Example 2 is shown. Figure 5 Example 2: Coulombic efficiency diagram of zinc full cell; Figure 6 Comparative Example 1 (Zn‖Zn symmetric cell) under the condition of 2.0 mA cm -2 2.0mAh cm -2 SEM image of the zinc anode surface after 25 cycles; Figure 7 This is a long-cycle test diagram of the zinc symmetric cell used in Comparative Example 1. Figure 8 Comparative Example 2 (Zn‖MnO2 full cell) under the condition of 1 A g -1 SEM image of the zinc anode surface after 25 cycles; Figure 9 The discharge specific capacity diagram of the zinc full cell in Comparative Example 2 is shown. Figure 10 The coulombic efficiency diagram for the zinc full cell in Comparative Example 2 is shown. Figure 11 This is a long-cycle test diagram of the zinc symmetric cell in Example 3; Figure 12 This is a long-cycle test diagram of the zinc symmetric cell in Example 4; Figure 13 This is a long-cycle test diagram of the zinc symmetric cell in Example 5; Figure 14 This is a long-cycle test diagram of the zinc symmetric cell in Example 6; Figure 15 This is a long-cycle test diagram of the zinc symmetric cell in Example 7; Figure 16 The XRD diffraction peak intensity diagrams of zinc sheets before and after soaking in 5g / L PLP for 12h according to the present invention are shown. Figure 17 The XRD peak intensity diagrams of the zinc sheet of the symmetrical battery of the present invention after 25 cycles of immersion in 5 g / L PLP for 12 h are shown. Figure 18 Zn in Example 1 2+ Transition number test graph; Figure 19 Zn for Comparative Example 1 2+ Transition number test graph; Figure 20 The diagram shows the timing current test (CA) for Example 1 and Comparative Example 1. Figure 21 The results of Tafel tests for Example 1 and Comparative Example 1 are shown. Figure 22 The results are linear sweep voltammetry (LSV) tests for Example 1 and Comparative Example 1. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0022] Experimental materials: zinc sulfate heptahydrate, pyridoxal phosphate (PLP), deionized water, ammonium vanadate (NH4V4O) 10 The fiberglass separator is GF / D Whatman.

[0023] Experimental equipment: deionized water purifier, magnetic stirrer, ultrasonic cleaner, drying oven, battery packaging machine, and blue-light testing system.

[0024] Example 1: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0025] II. Electrode Preparation 1. Weigh 0.2g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 5g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 12 hours; 4. After soaking for 12 hours, remove the zinc foil, rinse it with alcohol, and dry it for later use.

[0026] III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0027] IV. Battery Testing The battery was placed in the testing instrument, and the conditions were set to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0 mAh / cm³. -2 Long-cycle performance tests were conducted. The long-cycle test results for symmetrical cells immersed in zinc foil for 12 hours are shown in the figure below. Figure 2 As shown.

[0028] The equipment used in this process includes: a deionized water purifier, a magnetic stirrer, an ultrasonic cleaner, a drying oven, a battery packaging machine, and a Blue Electric testing system.

[0029] Example 2: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0030] II. Electrode Preparation positive electrode: 1. Weigh 50mg PVDF and place it in a bottle. Add 1.5ml nmp solution with a dropper and stir on a magnetic stirrer. After it is fully dissolved, weigh 100mg carbon black and 350mg ammonium vanadate and pour them into the stirred slurry. Add another 1.5ml nmp solution and stir. 2. After the slurry is thoroughly mixed, use a coating machine to evenly coat it onto the surface of the titanium foil. After cutting it to the appropriate size, place it in a vacuum drying oven at 80℃ for 12 hours to dry. 3. After the positive electrode material is dried, cut it into round pieces with a diameter of 12mm and keep them for later use.

[0031] negative electrode: 1. Weigh 0.2g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 5g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 12 hours; 4. After 12 hours, remove the soaked zinc foil, rinse it with alcohol, and dry it for later use.

[0032] III. Battery Assembly The zinc foil was used as the negative electrode, the titanium foil coated with the positive electrode material was used as the positive electrode, the glass fiber filter membrane was used as the separator, and 1 mol / L zinc sulfate was used as the electrolyte to assemble a CR2032 full cell.

[0033] IV. Battery Testing The batteries were placed in a battery testing instrument for long-cycle performance testing and coulombic efficiency testing. Results are attached. Figure 4 , 5 As shown.

[0034] Comparative Example 1: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0035] II. Electrode Preparation 1. Take a piece of zinc foil, ultrasonically clean it with anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12mm for later use, and mark it as B@Z; III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0036] IV. Battery Testing Place the battery in a battery testing instrument and set the conditions to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0mAh cm⁻¹. -2 Results attached Figure 7 As shown.

[0037] Comparative Example 2: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate and dissolve it in deionized water to prepare a 1 mol / L zinc sulfate electrolyte.

[0038] II. Electrode Preparation positive electrode: 1. Weigh 50mg PVDF and place it in a bottle. Add 1.5ml NMP solution using a weighing tube. Place the bottle on a magnetic stirrer and stir at medium speed until fully dissolved. Then weigh 100mg carbon black and 350mg ammonium vanadate and pour them into the stirred slurry. Add another 1.5ml NMP solution and stir at medium speed. 2. After the slurry is thoroughly mixed, use a coating machine to evenly coat it onto the surface of the titanium foil. After cutting it to the appropriate size, place it in a vacuum drying oven at 80℃ for 12 hours to dry. 3. After the positive electrode material is dried, cut it into round pieces with a diameter of 12mm and keep them for later use.

[0039] negative electrode: Take a piece of zinc foil, ultrasonically clean it with anhydrous ethanol for 20 minutes, then remove it and set it aside. Cut it into round pieces with a diameter of 12 mm.

[0040] III. Battery Assembly The zinc foil was used as the negative electrode, the titanium foil coated with the positive electrode material was used as the positive electrode, the glass fiber filter membrane was used as the separator, and 1 mol / L zinc sulfate was used as the electrolyte to assemble a CR2032 full cell.

[0041] IV. Battery Testing The batteries were placed in a battery testing instrument for long-cycle performance testing and coulombic efficiency testing. Results are attached. Figure 9 , 10 As shown.

[0042] Based on the coulomb efficiency diagram, the test results of Example 2 and Comparative Example 2 are summarized in Table 1: Table 1

[0043] Example 3: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0044] II. Electrode Preparation 1. Weigh 0.2g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 5g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 1 hour; 4. After soaking for 1 hour, remove the zinc foil, rinse it with alcohol, and dry it for later use.

[0045] III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0046] IV. Battery Testing The battery was placed in the testing instrument, and the conditions were set to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0 mAh / cm³. -2 Long-cycle performance tests were conducted. The results of the long-cycle test of the symmetric cell immersed in zinc foil for 1 hour are shown in the figure below. Figure 11 As shown.

[0047] The equipment used in this process includes: a deionized water purifier, a magnetic stirrer, an ultrasonic cleaner, a drying oven, a battery packaging machine, and a Blue Electric testing system.

[0048] Example 4: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0049] II. Electrode Preparation 1. Weigh 0.2g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 5g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 24 hours; 4. After soaking for 24 hours, remove the zinc foil, rinse it with alcohol, and dry it for later use.

[0050] III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0051] IV. Battery Testing The battery was placed in the testing instrument, and the conditions were set to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0 mAh / cm³. -2 Long-cycle performance tests were conducted. The results of the long-cycle test of the symmetric cell immersed in zinc foil for 24 hours are shown in the figure below. Figure 12 As shown.

[0052] The equipment used in this process includes: a deionized water purifier, a magnetic stirrer, an ultrasonic cleaner, a drying oven, a battery packaging machine, and a Blue Electric testing system.

[0053] Example 5: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0054] II. Electrode Preparation 1. Weigh 0.08g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 2g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 1 hour; 4. After soaking for 1 hour, remove the zinc foil, rinse it with alcohol, and dry it for later use.

[0055] III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0056] IV. Battery Testing The battery was placed in the testing instrument, and the conditions were set to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0 mAh / cm³. -2 Long-cycle performance tests were conducted. The results of the long-cycle test of the symmetric cell immersed in zinc foil for 1 hour are shown in the figure below. Figure 13 As shown.

[0057] The equipment used in this process includes: a deionized water purifier, a magnetic stirrer, an ultrasonic cleaner, a drying oven, a battery packaging machine, and a Blue Electric testing system.

[0058] Example 6: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0059] II. Electrode Preparation 1. Weigh 0.08g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 2g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 12 hours; 4. After soaking for 12 hours, remove the zinc foil, rinse it with alcohol, and dry it for later use.

[0060] III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0061] IV. Battery Testing The battery was placed in the testing instrument, and the conditions were set to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0 mAh / cm³.-2 Long-cycle performance tests were conducted. The results of the long-cycle test of the symmetric cell immersed in zinc foil for 12 hours are shown in the figure below. Figure 14 As shown.

[0062] The equipment used in this process includes: a deionized water purifier, a magnetic stirrer, an ultrasonic cleaner, a drying oven, a battery packaging machine, and a Blue Electric testing system.

[0063] Example 7: The specific implementation steps are as follows, and the entire process is carried out at room temperature and normal pressure. I. Electrolyte Preparation Weigh 2.87 g of zinc sulfate heptahydrate, dissolve the zinc sulfate heptahydrate in deionized water, and prepare a 1 mol / L zinc sulfate electrolyte.

[0064] II. Electrode Preparation 1. Weigh 0.08g of pyridoxal phosphate (PLP), dissolve pyridoxal phosphate (PLP) in deionized water, and prepare a 2g / L PLP solution; 2. Take a piece of zinc foil, ultrasonically clean it in anhydrous ethanol for 20 minutes, then remove it for later use and cut it into round pieces with a diameter of 12 mm and place them in a petri dish; 3. Pour the prepared PLP solution into the petri dish and immerse the zinc foil completely in the PLP solution for 24 hours; 4. After soaking for 24 hours, remove the zinc foil, rinse it with alcohol, and dry it for later use.

[0065] III. Battery Assembly Using the zinc foil as the positive and negative electrodes, the glass fiber filter membrane as the separator, and 1 mol / L zinc sulfate as the electrolyte, a CR2032 symmetrical cell was assembled.

[0066] IV. Battery Testing The battery was placed in the testing instrument, and the conditions were set to 2.0 mA cm. -2 The fixed charge / discharge capacity is 2.0 mAh / cm³. -2 Long-cycle performance tests were conducted. The results of the long-cycle test of the symmetric cell immersed in zinc foil for 24 hours are shown in the figure below. Figure 15 As shown.

[0067] The equipment used in this process includes: a deionized water purifier, a magnetic stirrer, an ultrasonic cleaner, a drying oven, a battery packaging machine, and a Blue Electric testing system.

[0068] This invention addresses the problem of uneven zinc ion deposition on the negative electrode in current aqueous zinc-ion batteries by proposing an anisotropic chemical etching strategy to construct a Zn anode with highly tunable surface and crystal planes. Scanning electron microscopy shows that the deposition morphology is optimized and dendrite formation is suppressed. X-ray diffraction was used to analyze the phase composition of PLP-treated (P@Z) and untreated (B@Z) samples after 12 hours, respectively. The intensity ratio of diffraction peaks on the (002) and (100) crystal planes, I(002) / I(100), reflects the degree of preferred orientation of the zinc negative electrode in the (002) crystal plane direction. The results are attached. Figure 16 , 17 As shown.

[0069] The test results show that: P@Z: I(002) / I(100) = 6.90 B@Z: I(002) / I(100) = 1.13 P@Z symmetry 25 circles: I(002) / I(100) = 8.15 B@Z symmetry 25 circles: I(002) / I(100) = 2.42 The above results indicate that the PLP-treated sample of this invention exhibits a significantly enhanced preferred orientation of the (002) crystal plane compared to the untreated sample. A higher I(002) / I(100) ratio favors the preferential exposure of the thermodynamically stable (002) plane, guiding Zn deposition along the (002) orientation and suppressing dendrite nucleation and growth. This, in turn, inhibits dendrite growth.

[0070] This demonstrates that the anisotropic chemical etching of this invention provides an effective and scalable approach to designing faceted Zn anodes with enhanced stability and rapid Zn etching. 2+ The kinetics provide important insights and design principles for next-generation high-performance aqueous Zn-ion batteries. The selected selective etching strategy has also been experimentally verified to effectively improve the cycle life of the zinc anode. Tests on zinc symmetric cells have consistently demonstrated its ability to significantly enhance the cycle life of the zinc anode.

[0071] Constant current charge-discharge curves under different conditions were recorded using a LAND battery testing instrument (Wuhan Land, CT3004A). Electrochemical impedance spectroscopy (EIS), chronoamperometric (CA) curves, linear sweep voltammetry (LSV) curves, and Tafel curves of Example 1 and Comparative Example 1 were measured using an electrochemical workstation (Shanghai Chenhua, CHI660E). The test results are as follows: Figures 18-22 As shown.

[0072] The ion transfer number was calculated using the electrochemical impedance spectroscopy (EIS), chronoamperometric curve (CA), and formula (1) of the symmetrical cell: ; Where ΔV is the applied voltage (15 mV), I0 and I1 are the initial response current and steady-state response current, and R0 and R1 are the initial charge transfer resistance and steady-state charge transfer resistance, respectively.

[0073] The above tests show that: 1. Through the long cycle test of symmetrical battery, the battery charge and discharge time can reach more than 1200 hours, which far exceeds the 200 hours of ordinary zinc battery. The test results of Example 1, Examples 3-7 and Comparative Example 1 are summarized in Table 2. Table 2

[0074] 2. Electron microscopy tests confirmed that the zinc anode surface was uniformly deposited after cycling, and the amount of dendrites was greatly reduced compared to ordinary aqueous zinc batteries; 3. By modifying the negative electrode, the battery's lifespan is increased, greatly reducing the cost of using the battery as an energy storage device. 4. Most large-scale energy storage systems currently use traditional capacitors to store energy, but due to their structure and other reasons, they pose problems such as explosion and environmental hazards. Aqueous batteries, on the other hand, have significant advantages over traditional capacitors, such as safety and no pollution.

[0075] 5. Figures 18-19 Zn 2+ The transfer number test results show that the interfacial impedance of the zinc anode in Example 1 did not increase, and the Zn 2 + The number of transfers increased significantly, and the increased number of transfers means that Zn 2+ Its contribution to ion transport increases; 6. Figure 20 Chronocurrent (CA) testing results show that the response current in Example 1 quickly stabilizes, consistent with a stable 3D diffusion-controlled growth process. This is beneficial for reducing dendrite formation.

[0076] 7. Figure 21 Tafel test results show that Example 1 exhibits a lower corrosion current density, which directly reflects the improved corrosion resistance of the zinc anode.

[0077] 8. Figure 22 Linear sweep voltammetry (LSV) also showed that the hydrogen evolution initiation potential shifted negatively, indicating that the hydrogen evolution reaction was suppressed.

[0078] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a modified aqueous zinc battery negative electrode, characterized in that, The specific steps are as follows: S1: Electrolyte preparation Dissolve zinc sulfate heptahydrate in water to obtain a zinc sulfate solution; S2: Preparation of negative electrode Dissolve pyridoxal phosphate in water to obtain a pyridoxal phosphate solution; fully immerse the pretreated zinc foil in the pyridoxal phosphate solution, denoted as P@Z, rinse and dry after immersion, and set aside for later use; S3: Battery Assembly Using P@Z as the negative electrode, glass fiber filter membrane as the separator, and zinc sulfate solution as the electrolyte, a symmetrical cell and a full cell are assembled. The positive and negative electrodes of the symmetrical battery both use P@Z, while the full battery uses P@Z only for the negative electrode.

2. The method for preparing a modified aqueous zinc battery negative electrode according to claim 1, characterized in that, The concentration of the zinc sulfate solution is 1 mol / L.

3. The method for preparing a modified aqueous zinc battery negative electrode according to claim 1, characterized in that, The concentration of the pyridoxal phosphate solution is 2-5 g / L.

4. The method for preparing a modified aqueous zinc battery negative electrode according to claim 1, characterized in that, The pretreatment involves ultrasonically cleaning the zinc foil in anhydrous ethanol for 20 minutes.

5. The method for preparing a modified aqueous zinc battery negative electrode according to claim 1, characterized in that, The soaking time is 1-24 hours.

6. The method for preparing a modified aqueous zinc battery negative electrode according to claim 1, characterized in that, The model number of the symmetrical battery and the full battery is CR2032.

7. The modified aqueous zinc battery anode obtained by any of the preparation methods described in claims 1-6.

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