A method for in-situ construction of a protective layer on the surface of a zinc anode of an aqueous zinc ion battery

Abstract

This invention discloses a method and application for in-situ construction of a protective layer on the surface of a zinc anode in an aqueous zinc-ion battery, belonging to the technical field of aqueous zinc-ion batteries. The method involves first pre-treating the zinc metal surface with progressive grinding and ultrasonic cleaning, then preparing a 2 mol / L zinc sulfate liquid electrolyte, to which (3-amino-3-carboxypropyl)dimethylsulfonium chloride (concentrations of 0.01, 0.02, and 0.05 mol / L) is added. After thorough stirring, the electrolyte is assembled with the pre-treated zinc electrode and a glass fiber filter membrane to form a Zn||Zn coin cell. Its core mechanism lies in the presence of -COOH, -NH2, and S in the additive molecules. + Synergistic effect of functional groups: -COOH and Zn² + Strong coordination regulates solvation structure and deposition behavior, forming a dense organic adsorption layer; -NH2 and Zn² + Weak coordination, synergistic homogenization of Zn² + Migration pathway; S + Introducing a positive charge onto the zinc surface creates a positively charged electrostatic shielding layer, suppressing parasitic reactions such as corrosion and hydrogen evolution. This method can construct a stable protective layer in situ, significantly improving battery cycle stability. Furthermore, the preparation process is simple and inexpensive, showing promising prospects for industrial application.

Description

Technical Field

[0001] This invention relates to the field of aqueous zinc-ion battery technology, and in particular to an additive for in-situ construction of a protective layer on the surface of the zinc anode of an aqueous zinc-ion battery and its application. Background Technology

[0002] Aqueous zinc-ion batteries, due to their advantages such as high safety, environmental friendliness, low cost, and high theoretical capacity, have shown broad application prospects in large-scale energy storage and portable electronic devices, becoming one of the current research hotspots in the field of electrochemical energy storage. Zinc anodes, as the core component of aqueous zinc-ion batteries, possess advantages such as high theoretical specific capacity (820 mAh / g), low redox potential (-0.76 V vs SHE), abundant resources, and good environmental compatibility, and are widely used as anode materials in aqueous zinc-ion batteries.

[0003] However, zinc anodes face serious stability issues in aqueous electrolytes, hindering the commercialization of aqueous zinc-ion batteries. On one hand, zinc metal is prone to uneven deposition during charging and discharging, forming zinc dendrites. The growth of these dendrites can puncture the separator, leading to internal short circuits and safety hazards. On the other hand, the high hydrophilicity of aqueous electrolytes causes corrosion and hydrogen evolution side reactions in the zinc anode, resulting in zinc metal loss and electrolyte decomposition, reducing the battery's coulombic efficiency and cycle life. Furthermore, the poor interfacial compatibility between the zinc anode and the electrolyte easily leads to the formation of an unstable solid electrolyte interphase (SEI) film, further exacerbating battery performance degradation.

[0004] To address these issues, researchers have employed various strategies, such as optimizing electrolyte composition, designing modified zinc anodes, and constructing artificial protective layers. Among these, adding functional additives to the electrolyte to create a stable protective layer in situ on the zinc anode surface is a simple, low-cost, and highly effective method. Existing technologies have reported various electrolyte additives, such as organic molecules, inorganic salts, and polymers, but these additives still have several shortcomings: some additives create protective layers with poor density, failing to effectively prevent contact between the electrolyte and the zinc anode; some additives have weak adhesion to the zinc anode and are prone to detachment during long-term cycling; and some additives reduce the ionic conductivity of the electrolyte, affecting the battery's rate performance. Therefore, developing an electrolyte additive capable of creating a dense, stable, and highly ionicly conductive protective layer in situ on the zinc anode surface is of great significance for improving the cycle stability and safety of aqueous zinc-ion batteries. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of dendrite growth, corrosion hydrogen evolution, and interface instability in existing aqueous zinc-ion batteries. It provides an additive for in-situ construction of a protective layer on the surface of the zinc anode of aqueous zinc-ion batteries and its application. The additive adsorbs on the surface of the zinc anode to form a dense, stable, and highly ionicly conductive protective layer, which effectively inhibits zinc dendrite growth and corrosion hydrogen evolution reaction, and improves the cycle stability and safety of the battery.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0008] Step S2: Preparation of liquid electrolyte Dissolve the zinc salt in deionized water and stir for 1-3 minutes to obtain a homogeneous solution.

[0009] Perform step S3: Add additives to the liquid electrolyte. Slowly pour the additive into the prepared liquid electrolyte and stir for 5-10 minutes to obtain a well-mixed solution.

[0010] Perform step S4: Assemble the battery and test its electrochemical performance. Pretreated zinc metal was assembled with a liquid electrolyte containing additives into a coin cell for electrochemical testing.

[0011] Based on the above technical solution, further, in step (2), the zinc salt is zinc sulfate.

[0012] Based on the above technical solution, further, in step (2), the concentration of the liquid electrolyte is 2 mol / L.

[0013] Based on the above technical solution, further, in step (3), the additive is one of (3-amino-3-carboxypropyl)dimethylsulfonium chloride (ACDC) and (2-carboxyethyl)dimethylsulfonium chloride (CEDMS-Cl). The additive molecule contains -COOH groups, -NH2 groups, and S... + Functional groups work synergistically to achieve dense construction of the protective layer and interface regulation.

[0014] Based on the above technical solution, further, in step (3), the concentration of the additive (3-amino-3-carboxypropyl)dimethylsulfonium chloride (ACDC) is 0.01-0.05 mol / L, and the concentration of the additive (2-carboxyethyl)dimethylsulfonium chloride (CEDMS-Cl) is 0.01-0.05 mol / L.

[0015] Based on the above technical solution, further, in step (4), the battery structure includes a positive electrode, a negative electrode, an electrolyte and a separator, wherein the battery casing is a CR2032 button battery casing, the positive electrode is NaV3O8·1.5H2O or metallic zinc, the negative electrode is metallic zinc, the electrolyte is a 2 mol / L zinc sulfate aqueous solution with selected additives added thereto, and the separator is a glass fiber filter membrane.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The additive of the present invention is obtained through the -COOH group, -NH2 group and S in the molecule. + The synergistic effect of functional groups constructs a dense and stable protective layer in situ on the zinc anode surface: -COOH groups and Zn²⁻ + Strong coordination is formed, which can both regulate the solvation structure and zinc deposition behavior, and form a dense organic adsorption layer; -NH2 groups and Zn²⁺ + Establishing weak coordination to synergistically homogenize Zn² with -COOH + Migration pathways ensure uniform zinc ion deposition and inhibit dendrite growth; S + A positively charged interface layer is formed near the zinc surface, which effectively inhibits parasitic reactions such as corrosion and hydrogen evolution, thus solving the stability problem of zinc negative electrode from the root; at the same time, it does not affect the rapid transport of zinc ions, ensuring the rate performance of the battery.

[0017] (2) The electrolyte containing the additives of the present invention has a simple preparation process, is easy to operate, has low energy consumption, does not require complex equipment, and is suitable for large-scale production; moreover, the amount of additives used is small and the cost is low, which will not significantly increase the preparation cost of the battery and has good prospects for industrial application. Attached Figure Description

[0018] Figure 1 Example 1 shows a Zn||Zn symmetric cell at 0.5 mA cm⁻² and 0.5 mAh cm⁻². X-ray photoelectron spectra of the zinc anode surface after 50 cycles under condition 2.

[0019] Figure 2 Examples 1 and 1 Comparative Example 1 are Zn||Zn symmetric cells at 5 mA cm⁻² and 5 mAh cm⁻². Scanning electron microscope image of the zinc anode surface after 50 cycles under condition 2.

[0020] Figure 3 Example 1 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². X-ray diffraction pattern after 50 cycles under condition 2.

[0021] Figure 4 This is the corrosion curve of Example 1. Figure 5 This is the corrosion curve of Example 2. Figure 6 This is the corrosion curve of Example 3. Figure 7 The corrosion curve is for Comparative Example 1. Figure 8 Corrosion curves of Comparative Example 2 Figure 9 The corrosion curve is shown in Comparative Example 3. Figure 10 Example 1 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 11 Example 2 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 12 Example 3 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 13 Example 1 shows a Zn||Zn symmetric cell at 10 mA cm⁻² and 10 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 14 Comparative Example 1: Zn||Zn symmetric cell at 5 mA cm⁻², 5 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 15 Comparative Example 1: Zn||Zn symmetric cell at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 16 Comparative Example 2 Zn||Zn symmetric cell at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 17 Comparative Example 3 Zn||Zn symmetric cell at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 18 Comparative example 4 Zn||Zn symmetric cells at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 19 Example 4: Zn||NVO full cell at 5 A g Cyclic life diagram under condition 1 Figure 20 Comparative ratio 5 Zn||NVO full cell at 5 A g Cyclic life diagram under condition 1 Detailed Implementation The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0022] Unless otherwise specified, the experimental procedures or conditions in these examples were performed in accordance with conventional experimental procedures and conditions described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available.

[0023] In order to more intuitively reveal the technical solution of the present invention and highlight its beneficial effects, the electrochemical performance of the present invention will now be described in conjunction with specific embodiments.

[0024] Example 1 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0025] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0026] Perform step S3: Add additives to the liquid electrolyte. 0.0005 mol of (3-amino-3-carboxypropyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0027] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively. A glass fiber filter membrane was used as the separator, and a 2 mol / L zinc sulfate + 0.05 mol / L (3-amino-3-carboxypropyl)dimethylsulfonium chloride aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and connected to a 5 mA cm⁻², 5 mAh cm⁻², and 1000 mAh / cm² battery. Cyclic testing was performed under condition 2.

[0028] Example 2 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0029] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0030] Perform step S3: Add additives to the liquid electrolyte. 0.0002 mol of (3-amino-3-carboxypropyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0031] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively. A glass fiber filter membrane was used as the separator, and a 2 mol / L zinc sulfate + 0.02 mol / L (3-amino-3-carboxypropyl)dimethylsulfonium chloride aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and connected to a 5 mA cm⁻², 5 mAh cm⁻², and 5 mAh cm⁻² batteries. Cyclic testing was performed under condition 2.

[0032] Example 3 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0033] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0034] Perform step S3: Add additives to the liquid electrolyte. 0.0001 mol of (3-amino-3-carboxypropyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0035] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively. A glass fiber filter membrane was used as the separator, and a 2 mol / L zinc sulfate + 0.01 mol / L (3-amino-3-carboxypropyl)dimethylsulfonium chloride aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and connected to a power supply at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic testing was performed under condition 2.

[0036] Example 4 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0037] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0038] Perform step S3: Add additives to the liquid electrolyte. 0.0005 mol of (3-amino-3-carboxypropyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0039] Perform step S4: Assemble the battery and test its electrochemical performance. 4 g of V₂O₅ powder was dispersed in 60 mL of 2 M NaCl aqueous solution and stirred at room temperature for 96 hours. The resulting product was thoroughly rinsed with deionized water and then freeze-dried to obtain NaV₃O₈·1.5H₂O. A positive electrode material was prepared by mixing NaV₃O₈·1.5H₂O powder, acetylene black, and polyvinylidene fluoride (PVDF) in a mass ratio of 7:2:1 using N-methyl-2-pyrrolidone (NMP) as solvent. A Zn||NVO full cell was assembled using pretreated zinc as the negative electrode, a glass fiber filter membrane as the separator, and a 2 mol / L zinc sulfate + 0.05 mol / L (3-amino-3-carboxypropyl)dimethylsulfonium chloride aqueous solution as the electrolyte. The cell was tested at 5 A g⁻¹.

[0040] Comparative Example 1 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0041] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0042] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively. A glass fiber filter membrane was used as the separator, and a 2 mol / L zinc sulfate aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and connected to a 5 mA cm⁻², 5 mAh cm⁻², and 5 mAh cm⁻² batteries. Cyclic testing was performed under condition 2.

[0043] Comparative Example 2 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0044] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0045] Perform step S3: Add additives to the liquid electrolyte. 0.0005 mol of (2-carboxyethyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0046] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively, with a glass fiber filter membrane as the separator. A 2 mol / L zinc sulfate + 0.05 mol / L (2-carboxyethyl)dimethylsulfonium chloride aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and operated at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic testing was performed under condition 2.

[0047] Comparative Example 3 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0048] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0049] Perform step S3: Add additives to the liquid electrolyte. 0.001 mol of (3-amino-3-carboxypropyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0050] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively, with a glass fiber filter membrane as the separator. A 2 mol / L zinc sulfate + 0.1 mol / L (3-amino-3-carboxypropyl)dimethylsulfonium chloride aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and operated at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic testing was performed under condition 2.

[0051] Comparative Example 4 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0052] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0053] Perform step S3: Add additives to the liquid electrolyte. 0.001 mol of (2-carboxyethyl)dimethylsulfonium chloride was slowly poured into a prepared 2 mol / L zinc sulfate aqueous solution and stirred for 5-10 min to obtain a homogeneous electrolyte.

[0054] Perform step S4: Assemble the battery and test its electrochemical performance. Two pretreated zinc plates were used as the positive and negative electrodes, respectively, with a glass fiber filter membrane as the separator. A 2 mol / L zinc sulfate + 0.1 mol / L (2-carboxyethyl)dimethylsulfonium chloride aqueous solution was used as the electrolyte. A Zn||Zn battery was assembled using a CR2032 coin cell casing and operated at 10 mA cm⁻² and 10 mAh cm⁻². Cyclic testing was performed under condition 2.

[0055] Comparative Example 5 Step S1: Zinc metal surface pretreatment Grinding was performed using 800, 1500, and 3000 grit sandpaper in successive stages. After grinding, the metal surface was ultrasonically cleaned with ethanol for 2-5 minutes, and then dried at room temperature before use.

[0056] Step S2: Preparation of liquid electrolyte Dissolve 0.02 mol zinc sulfate in 10 ml of deionized water and stir for 1-3 min to obtain a 2 mol / L zinc sulfate aqueous solution.

[0057] Perform step S4: Assemble the battery and test its electrochemical performance. 4 g of V₂O₅ powder was dispersed in 60 mL of 2 M NaCl aqueous solution and stirred at room temperature for 96 hours. The resulting product was thoroughly rinsed with deionized water and then freeze-dried to obtain NaV₃O₈·1.5H₂O. A positive electrode material was prepared by mixing NaV₃O₈·1.5H₂O powder, acetylene black, and polyvinylidene fluoride (PVDF) in a mass ratio of 7:2:1 using N-methyl-2-pyrrolidone (NMP) as the solvent. A Zn||NVO full cell was assembled using pretreated zinc as the negative electrode, a glass fiber filter membrane as the separator, and a 2 mol / L zinc sulfate aqueous solution as the electrolyte, and tested under 5 A g⁻¹ conditions using a CR2032 coin cell case.

[0058] Figure 1 Example 1 shows a Zn||Zn symmetric cell at 0.5 mA cm⁻² and 0.5 mAh cm⁻². X-ray photoelectron spectra of the zinc anode surface after 50 cycles under condition 2.

[0059] Figure 2 Examples 1 and 1 Comparative Example 1 are Zn||Zn symmetric cells at 5 mA cm⁻² and 5 mAh cm⁻². Scanning electron microscope image of the zinc anode surface after 50 cycles under condition 2.

[0060] Figure 3 Example 1 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². X-ray diffraction pattern after 50 cycles under condition 2.

[0061] Figure 4 This is the corrosion curve of Example 1. Figure 5 This is the corrosion curve of Example 2. Figure 6 This is the corrosion curve of Example 3. Figure 7 The corrosion curve is for Comparative Example 1. Figure 8 Corrosion curves of Comparative Example 2 Figure 9 The corrosion curve is shown in Comparative Example 3. Figure 10 Example 1 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 11 Example 2 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 12 Example 3 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 13 Example 1 shows a Zn||Zn symmetric cell at 10 mA cm⁻² and 10 mAh cm⁻². Cyclic life diagram under 2 conditions Figure 14 Comparative Example 1: Zn||Zn symmetric cell at 5 mA cm⁻², 5 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 15Comparative Example 1: Zn||Zn symmetric cell at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 16 Comparative Example 2 Zn||Zn symmetric cell at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 17 Comparative Example 3 Zn||Zn symmetric cell at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 18 Comparative example 4 Zn||Zn symmetric cells at 10 mA cm⁻², 10 mAh cm⁻² Cyclic life diagram under 2 conditions Figure 19 Example 4: Zn||NVO full cell at 5 A g Cyclic life diagram under condition 1 Figure 20 Comparative ratio 5 Zn||NVO full cell at 5 A g Cyclic life diagram under condition 1 in, Figure 1 Example 1 shows a Zn||Zn symmetric cell at 0.5 mA cm⁻² and 0.5 mAh cm⁻². X-ray photoelectron spectroscopy (XPS) of the zinc anode surface after 50 cycles under condition 2. The test results showed a CS-Zn characteristic peak in the S 2p orbital, indicating that the additive successfully formed a SEI protective layer on the surface, confirming the S... + The mechanism by which it participates in the construction of the interface layer.

[0062] Figure 2 When the electrolytes prepared in Example 1 and Comparative Example 1 are applied to aqueous zinc-ion batteries, they exhibit performance at 5 mA cm⁻² and 5 mAh cm⁻². The scanning electron microscope (SEM) images of the zinc anode surface after 50 cycles under condition 2 show that no obvious dendrites were found on the surface of the zinc anode in Example 1, indicating that the -COOH and -NH2 groups in the additive synergistically and uniformly form Zn²⁺. + The migration pathway enabled dense and uniform zinc deposition.

[0063] Figure 3 Example 1 shows a Zn||Zn symmetric cell at 5 mA cm⁻² and 5 mAh cm⁻². The X-ray diffraction pattern after 50 cycles under condition 2 showed no characteristic peaks of byproducts, indicating that S +The formed positively charged interface layer effectively suppresses parasitic reactions such as hydrogen evolution and reduces the formation of byproducts.

[0064] Figure 4-9 The corrosion curves are for Examples 1-3 and Comparative Examples 1-3. In the test results, the corrosion current of Example 1 is the lowest compared with that of Examples 1-3, indicating that the optimal concentration of additive (3-amino-3-carboxypropyl)dimethylsulfonium chloride is 0.05 mol / L. Moreover, the corrosion current of Examples 1-3 is lower than that of Comparative Examples 1-3, indicating that the SEI protective layer constructed in situ by the synergistic use of the three functional groups -COOH, -NH2 and S+ can effectively reduce the corrosion efficiency of the battery.

[0065] Figure 10-13 This is a cycle life graph of Examples 1-3 and Comparative Example 1. The test results show that the Zn||Zn symmetric cells of Examples 1-3 achieved cycle life at 5 mA cm⁻² and 5 mAh cm⁻². The cycle times under condition 2 were greater than those under comparative example 1, indicating that the in-situ constructed SEI protective layer can effectively enhance the cycle stability of the battery.

[0066] Figure 14-16 These are cycle life graphs for Example 1 and Comparative Examples 1-2. The test results show that the Zn||Zn symmetric cell of Example 1, at a high current of 10 mA cm⁻² and 10 mAh cm⁻², [the following parameters are missing from the original text]. The cycle time under condition 2 is also greater than that of comparative examples 1-3, indicating that even under harsh conditions, the in-situ constructed SEI protective layer can still enhance the cycle stability of the battery.

[0067] Figure 17-18 The chart shows the cycle life of Comparative Examples 3-4. The test results indicate that when the amount of additive used exceeds 0.05 mol / L, the cycle time is shortened. However, the performance of additive ACCDC is still superior to CEDMS-Cl, proving that this numerical range and the choice of substance are not coincidental. Figures 19-20 The results show the cycle test results of Example 4 and Comparative Example 5. In the test results, the Zn||NVO full cell of Example 4 maintained a capacity retention of 77.6% after 2000 cycles at a current density of 5 A g-1, which is much higher than the capacity retention of 43.4% in Comparative Example 5. This indicates that the selected additive can also effectively improve the performance when applied to other electrochemical energy storage devices.

[0068] Table 1. List of electrochemical performance of Examples 1-3 and Comparative Examples 1-4

[0069] Table 2. Electrochemical performance list of Example 4 and Comparative Example 5

Claims

1. A method for in-situ constructing a protective layer on the surface of the zinc anode of an aqueous zinc-ion battery, characterized in that, Includes the following steps: (1) Dissolve zinc salt in water to obtain a liquid electrolyte; (2) Mix the additive with the liquid electrolyte; (3) Grind the zinc metal and clean it with ethanol to remove the oxide layer on the surface; (4) The obtained electrolyte and zinc sheet are assembled into a button cell and cycled to realize the in-situ construction of a protective layer on the zinc negative electrode surface during the cycle.

2. The method for in-situ constructing a protective layer on the surface of the zinc negative electrode of an aqueous zinc-ion battery according to claim 1, characterized in that, In step (1), the zinc salt is zinc sulfate with a concentration of 2 mol / L.

3. The method for in-situ constructing a protective layer on the surface of the zinc negative electrode of an aqueous zinc-ion battery according to claim 1, characterized in that, In step (2), the additive is one of (3-amino-3-carboxypropyl)dimethylsulfonium chloride (ACDC) and (2-carboxyethyl)dimethylsulfonium chloride (CEDMS-Cl).

4. The method for in-situ constructing a protective layer on the surface of the zinc negative electrode of an aqueous zinc-ion battery according to claim 1, characterized in that, In step (2), the concentration of the additive is 0.01-0.05 mol / L.

5. The method for in-situ constructing a protective layer on the surface of the zinc negative electrode of an aqueous zinc-ion battery according to claim 1, characterized in that, In step (3), the zinc sheet has a thickness of 100 μm.

6. The method for in-situ constructing a protective layer on the surface of the zinc negative electrode of an aqueous zinc-ion battery according to claim 1, characterized in that, In step (3), the polishing process involves using 800, 1500, and 3000 grit sandpaper for progressive processing, followed by ultrasonic cleaning in ethanol for 2-5 minutes, and drying to obtain pretreated metallic zinc.

7. The method for in-situ constructing a protective layer on the surface of the zinc negative electrode of an aqueous zinc-ion battery according to claim 1, characterized in that, The zinc-ion battery described in step (4) uses a CR2032 button cell casing and a glass fiber filter membrane.

8. An aqueous zinc-ion battery prepared by the method of claims 1-7.

9. The additive according to claim 3 can be used in electrochemical energy storage devices.

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