Aqueous zinc ion battery electrolyte, preparation method thereof and aqueous zinc ion battery

Abstract

The application belongs to the technical field of zinc ion batteries, and provides a water-based zinc ion battery electrolyte, a preparation method thereof and a water-based zinc ion battery. The application provides a water-based zinc ion battery electrolyte comprising the following components: a water-soluble zinc salt 1-2.5 mol / L, an additive 1-6 g / L and water; the additive is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane, and the pH value of the water-based zinc ion battery electrolyte is less than or equal to 1. The additive of the application is preferentially adsorbed on the surface of the zinc negative electrode instead of water molecules, and generates a thin and dense solid-state protective layer in situ, which has good ion conductivity and is electron-insulating. The solid-state protective layer is like a raincoat for the zinc negative electrode, which prevents water molecules from reacting with the zinc negative electrode, and at the same time, the tertiary amine ions formed by the ionization of the bridging crown ether shield the corrosion of hydrogen ions on the zinc negative electrode under strong acid conditions.

Description

Technical Field

[0001] This invention relates to the field of zinc-ion battery technology, and in particular to an aqueous zinc-ion battery electrolyte, its preparation method, and an aqueous zinc-ion battery. Background Technology

[0002] The demand for electrochemical energy storage devices is currently increasing dramatically. To meet the needs of ecological and economical energy storage systems, there is a need to develop rechargeable batteries that are low-cost, highly safe, long-life, and have high energy density. Although lithium-ion batteries have made significant progress, challenges such as toxic and flammable solvents and high-cost electrode materials remain, limiting their large-scale application. In contrast, zinc anodes offer outstanding advantages: abundant reserves, air stability, and a high theoretical capacity (820 mAh·g). -1 The low redox potential (-0.76V vs. standard hydrogen electrode) and inherent safety of aqueous zinc-ion batteries make them a candidate for next-generation energy storage. However, due to side reactions at the zinc anode, such as electrochemical corrosion, hydrogen evolution reaction, etc., aqueous zinc-ion batteries are still in the early stages of development and have not yet been put into practical use.

[0003] Most aqueous zinc-ion batteries use a single salt solution as the electrolyte, such as zinc sulfate or zinc chloride solutions, but their ionic conductivity and interfacial stability are not ideal. Persistent challenges associated with the zinc anode, such as electrochemical corrosion, hydrogen evolution reaction, and dendrite formation, lead to problems like anodic corrosion, low coulombic efficiency, capacity decay, and shortened lifespan. Furthermore, conventional electrolytes have limited effectiveness in inhibiting the dissolution of cathode materials (such as manganese-based oxides), resulting in significant loss of active material during long-term cycling. Existing technologies improve performance by adding small-molecule additives to the electrolyte solution, but some additives significantly increase cost and viscosity, limiting practical applications. In addition, research indicates that under strongly acidic conditions, hydrogen ion intercalation may be used to break through the theoretical capacity of manganese-based or vanadium-based oxides, thereby achieving higher energy storage capabilities. However, under strongly acidic conditions (especially pH < 1), zinc reacts strongly with the acid, corroding the zinc anode and generating large amounts of hydrogen gas. Current conventional electrolyte designs struggle to achieve stable cycling of the zinc anode at pH < 1. Therefore, solving the electrochemical cycle stability of zinc anodes under strong acid conditions has become the key to developing zinc-ion batteries with high energy storage capacity. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an aqueous zinc-ion battery electrolyte, a method for preparing the same, and an aqueous zinc-ion battery. The aqueous zinc-ion battery electrolyte of this invention can protect the zinc anode under strongly acidic conditions and maintain the cycle stability of the aqueous zinc-ion battery.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides an aqueous zinc-ion battery electrolyte, comprising the following components: Water-soluble zinc salts, additives, and water; In the aqueous zinc-ion battery electrolyte, the concentration of water-soluble zinc salt is 1~2.5 mol / L, and the concentration of additives is 1~6 g / L; The additive is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane, and the structure of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is shown in Formula 1: Formula 1; The pH value of the aqueous zinc-ion battery electrolyte is less than or equal to 1.

[0006] Preferably, the water-soluble zinc salt is one or more of zinc sulfate, zinc gluconate, zinc acetate, and zinc trifluoromethanesulfonate.

[0007] Preferably, the aqueous zinc-ion battery electrolyte further includes an inorganic acid, including concentrated nitric acid, the concentration of which is 68 wt%, and the volume content of the concentrated nitric acid in the aqueous zinc-ion battery electrolyte is 0.5-3%.

[0008] Preferably, the water is deionized water.

[0009] This invention also provides a method for preparing the aqueous zinc-ion battery electrolyte described in the above technical solution, comprising the following steps: A zinc salt solution is obtained by mixing water-soluble zinc salt with water. The zinc salt solution and additives are mixed, the pH value is adjusted, and the volume is brought to a final consistency to obtain the aqueous zinc-ion battery electrolyte.

[0010] The present invention also provides an aqueous zinc-ion battery, comprising an electrolyte, wherein the electrolyte is the aqueous zinc-ion battery electrolyte described in the above technical solution or the aqueous zinc-ion battery electrolyte prepared by the preparation method described in the above technical solution.

[0011] Preferably, the aqueous zinc-ion battery further includes a positive electrode material, a negative electrode material, and a separator.

[0012] Preferably, the cathode material includes one or more of manganese-based oxides, vanadium-based oxides, and Prussian blue analogues.

[0013] Preferably, the negative electrode material includes one or more of zinc foil, zinc alloy, and carbon materials.

[0014] Preferably, the diaphragm is one or more of glass fiber diaphragm, polypropylene diaphragm, and cellulose diaphragm.

[0015] This invention provides an aqueous zinc-ion battery electrolyte.

[0016] This invention uses the macrocyclic crown ether organic compound 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane (hereinafter referred to as crown ether molecule) as an additive in the electrolyte of an aqueous zinc-ion battery. The crown ether molecule possesses a unique molecular structure of "lipophilic inner cavity and hydrophilic outer cavity." The oxygen atoms in the crown ether molecule have lone pairs of electrons, exhibiting strong affinity and adsorption capacity for highly active sites (such as grain boundaries and defects) or deposited zinc atoms on the zinc metal surface. The crown ether molecule preferentially adsorbs onto the zinc anode surface before water molecules, forming a thin, dense, ionicly conductive, and electronically insulating solid protective layer in situ. This solid protective layer acts like a "raincoat" for the zinc anode. Through the regulation of the interface environment, the solid protective layer forms a physical barrier that prevents water molecules from interacting with the zinc anode. At the same time, it shields the zinc anode from the corrosion of hydrogen ions under strong acid conditions by tertiary amine ions formed by the ionization of tertiary amine in the bridged crown ether, effectively inhibiting the hydrogen evolution reaction. Furthermore, it ensures the deposition and stripping of zinc ions by transferring zinc ions through the bridged oxygen. Therefore, the zinc anode can operate at room temperature for over 6000 hours under strong acid conditions with a pH less than 0.8.

[0017] This invention reduces costs and maintains a high ionic conductivity of over 27 mS / cm in aqueous zinc-ion battery electrolytes by adding trace amounts of macrocyclic crown ethers, specifically 27.33~39.14 mS / cm. Attached Figure Description

[0018] Figure 1 Optical photographs of the electrolytes obtained in Comparative Example 1 and Example 1 after immersing the zinc anode for more than three days; Figure 2 To test the Zn||Cu half-cell constructed using the electrolytes obtained in Comparative Example 1 and Example 1 at 25°C and 1 mA·cm⁻¹ -2 The following is a graph showing the Coulomb efficiency test results; Figure 3 To test the Zn||Zn symmetric cells constructed using the electrolytes obtained in Comparative Example 1 and Example 1 at 25°C and 1 mAh·cm⁻¹ -2 The following is a graph showing the results of the magnification test; Figure 4 To test the Zn||Zn symmetric cells constructed using the electrolytes obtained in Comparative Example 1 and Example 1 at 25°C and 1 mA·cm⁻¹ -2 1mAh·cm -2 The following is a graph showing the results of the loop test. Detailed Implementation

[0019] This invention provides an aqueous zinc-ion battery electrolyte, comprising the following components: Water-soluble zinc salts, additives, and water; In the aqueous zinc-ion battery electrolyte, the concentration of water-soluble zinc salt is 1~2.5 mol / L, and the concentration of additives is 1~6 g / L; The additive is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane, and the structure of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is shown in Formula 1: Formula 1; The pH value of the aqueous zinc-ion battery electrolyte is less than or equal to 1.

[0020] Unless otherwise specified, the raw materials used in this invention are preferably commercially available products.

[0021] The aqueous zinc-ion battery electrolyte provided by this invention comprises a water-soluble zinc salt. The concentration of the water-soluble zinc salt in the aqueous zinc-ion battery electrolyte is 1~2.5 mol / L, preferably 1.8~2.2 mol / L, and specifically preferably 1 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, 2.2 mol / L, or 2.5 mol / L. In this invention, the water-soluble zinc salt is preferably one or more of zinc sulfate, zinc gluconate, zinc acetate, and zinc trifluoromethanesulfonate, and more preferably zinc sulfate or zinc trifluoromethanesulfonate. In this invention, the zinc sulfate is preferably one or more of anhydrous zinc sulfate, zinc sulfate monohydrate, and zinc sulfate heptahydrate.

[0022] The aqueous zinc-ion battery electrolyte provided by this invention includes an additive. The concentration of the additive in the aqueous zinc-ion battery electrolyte is 1~6 g / L, specifically preferably 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L, 3 g / L, 3.5 g / L, 4 g / L, 4.5 g / L, 5 g / L, 5.5 g / L, or 6 g / L. In this invention, the additive is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane, and the structure of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is shown in Formula 1. Formula 1.

[0023] The aqueous zinc-ion battery electrolyte provided by this invention uses 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane (C 18 H36 N2O6, as an additive, can effectively optimize zinc deposition behavior and suppress side reactions, thereby significantly improving the cycle life and energy efficiency of aqueous zinc-ion batteries. Aqueous zinc-ion batteries constructed based on this electrolyte exhibit excellent reversibility and long-term cycle stability, capable of continuous operation for over 6000 hours at room temperature. Meanwhile, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is characterized by low concentration, low toxicity, safety, and environmental friendliness, significantly reducing production costs and solving the problems of performance, cost, and environmental friendliness associated with existing conventional aqueous zinc-ion battery electrolytes.

[0024] The aqueous zinc-ion battery electrolyte provided by the present invention includes water, preferably deionized water.

[0025] In this invention, the pH value of the aqueous zinc-ion battery electrolyte is less than or equal to 1, more preferably less than or equal to 0.9, and specifically preferably 0.600, 0.667 or 0.867.

[0026] The aqueous zinc-ion battery electrolyte provided by this invention preferably further includes an inorganic acid, which preferably includes concentrated nitric acid, and the concentration of the concentrated nitric acid is preferably 68 wt%. In this invention, the volume content of concentrated nitric acid in the aqueous zinc-ion battery electrolyte is preferably 0.5-3%, specifically preferably 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%. In this invention, the inorganic acid is used to adjust the pH value of the aqueous zinc-ion battery electrolyte to be less than or equal to 1.

[0027] In this invention, the preferred operating temperature of the aqueous zinc-ion battery electrolyte is 25°C.

[0028] This invention focuses on optimizing the zinc anode surface using an electrolyte. Water is used as the primary solvent, and 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is used as an additive. Through the interaction between the nitrogen and oxygen atoms in the macrocyclic crown ether structure of the additive and the zinc ions / zinc surface, the interfacial environment is effectively regulated: on the one hand, a physical barrier is formed and the interfacial water activity is reduced, inhibiting side reactions such as hydrogen evolution and corrosion caused by water molecules contacting the zinc surface; on the other hand, the zinc ion flow is homogenized, guiding zinc ions to undergo uniform and dense deposition at their adsorption sites. During the initial deposition process, some adsorbed additive molecules or their derivatives react with zinc ions, generating a thin, dense, ionicly conductive, and electronically insulating solid protective layer in situ. This solid protective layer remains stable in subsequent cycles, continuously isolating the active material from direct contact with the electrolyte and inhibiting dendrite growth, thereby significantly improving the stability and reversibility of the zinc anode.

[0029] This invention also provides a method for preparing the aqueous zinc-ion battery electrolyte described in the above technical solution, comprising the following steps: A zinc salt solution is obtained by mixing water-soluble zinc salt with water. The zinc salt solution and additives are mixed, the pH value is adjusted, and the volume is brought to a final consistency to obtain the aqueous zinc-ion battery electrolyte.

[0030] This invention involves mixing water-soluble zinc salts with water to obtain a zinc salt solution.

[0031] The present invention does not specifically limit the operation of mixing the water-soluble zinc salt and water, as long as the two can be mixed evenly.

[0032] After obtaining the zinc salt solution, the present invention mixes the zinc salt solution with additives, adjusts the pH value and makes up the volume to obtain the aqueous zinc ion battery electrolyte.

[0033] In this invention, the zinc salt solution and additives are preferably mixed under stirring conditions. This invention does not specifically limit the stirring speed and time, as long as a colorless and transparent system can be formed.

[0034] The present invention also provides an aqueous zinc-ion battery, comprising an electrolyte, wherein the electrolyte is the aqueous zinc-ion battery electrolyte described in the above technical solution or the aqueous zinc-ion battery electrolyte prepared by the preparation method described in the above technical solution.

[0035] The aqueous zinc-ion battery provided by the present invention includes an electrolyte, wherein the electrolyte is the aqueous zinc-ion battery electrolyte described in the above technical solution or the aqueous zinc-ion battery electrolyte prepared by the preparation method described in the above technical solution.

[0036] The aqueous zinc-ion battery provided by this invention preferably further includes a positive electrode material. In this invention, the positive electrode material preferably includes one or more of manganese-based oxides, vanadium-based oxides, and Prussian blue analogues.

[0037] The aqueous zinc-ion battery provided by the present invention preferably further includes a negative electrode material, which preferably includes one or more of zinc foil, zinc alloy and carbon material.

[0038] The aqueous zinc-ion battery provided by the present invention preferably further includes a separator, wherein the separator is preferably one or more of glass fiber separator, polypropylene separator and cellulose separator.

[0039] The aqueous zinc-ion battery electrolyte, its preparation method, and the aqueous zinc-ion battery provided by the present invention will be described in detail below with reference to the embodiments. However, these should not be construed as limiting the scope of protection of the present invention.

[0040] Example 1 An aqueous zinc-ion battery electrolyte is provided, which uses zinc sulfate heptahydrate as the zinc salt, deionized water as the main solvent, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane as an additive, and concentrated nitric acid with a mass content of 68% as a pH adjuster to form an aqueous zinc-ion battery electrolyte.

[0041] Taking the preparation of 1L electrolyte as an example, the preparation method is as follows: First, dissolve 2mol of zinc sulfate heptahydrate in deionized water and mix. Then add 4g of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane and 10mL of concentrated nitric acid (accounting for 1% of the total volume of the aqueous zinc-ion battery electrolyte). Stir until a colorless and transparent solution is formed. Finally, transfer it to a 1L volumetric flask, dilute it with deionized water and make up to volume. The pH value of the resulting aqueous zinc-ion battery electrolyte is 0.667.

[0042] Example 2 An aqueous zinc-ion battery electrolyte is provided, which uses zinc sulfate heptahydrate as the zinc salt, deionized water as the main solvent, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane as an additive, and concentrated nitric acid with a mass content of 68% as a pH adjuster to form an aqueous zinc-ion battery electrolyte.

[0043] Taking the preparation of 1L electrolyte as an example, the preparation method is as follows: First, dissolve 1.8mol of zinc sulfate heptahydrate in deionized water and mix. Then add 4g of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane and 10mL of concentrated nitric acid (accounting for 1% of the total volume of the aqueous zinc-ion battery electrolyte). Stir until a colorless and transparent solution is formed. Finally, transfer it to a 1L volumetric flask, dilute it with deionized water and make up to volume. The pH value of the resulting aqueous zinc-ion battery electrolyte is 0.667.

[0044] Example 3 An aqueous zinc-ion battery electrolyte is provided, which uses zinc sulfate heptahydrate as the zinc salt, deionized water as the main solvent, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane as an additive, and concentrated nitric acid with a mass content of 68% as a pH adjuster to form an aqueous zinc-ion battery electrolyte.

[0045] Taking the preparation of 1L electrolyte as an example, the preparation method is as follows: First, dissolve 2mol of zinc sulfate heptahydrate in deionized water and mix. Then add 2g of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane and 5mL of concentrated nitric acid (accounting for 0.5% of the total volume of the aqueous zinc-ion battery electrolyte). Stir until a colorless and transparent solution is formed. Finally, transfer it to a 1L volumetric flask, dilute it with deionized water and make up to volume. The pH value of the resulting aqueous zinc-ion battery electrolyte is 0.867.

[0046] Example 4 An aqueous zinc-ion battery electrolyte is provided, which uses zinc sulfate heptahydrate as the zinc salt, deionized water as the main solvent, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane as an additive, and concentrated nitric acid with a mass content of 68% as a pH adjuster to form an aqueous zinc-ion battery electrolyte.

[0047] Taking the preparation of 1L electrolyte as an example, the preparation method is as follows: First, dissolve 2mol of zinc sulfate heptahydrate in deionized water and mix. Then add 6g of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane and 10mL of concentrated nitric acid (accounting for 1% of the total volume of the aqueous zinc-ion battery electrolyte). Stir until a colorless and transparent solution is formed. Finally, transfer it to a 1L volumetric flask, dilute it with deionized water and make up to volume. The pH value of the resulting aqueous zinc-ion battery electrolyte is 0.600.

[0048] Example 5 An aqueous zinc-ion battery electrolyte is provided, using zinc trifluoromethanesulfonate as the zinc salt, deionized water as the main solvent, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane as an additive, and concentrated nitric acid with a mass content of 68% as a pH adjuster, to form an aqueous zinc-ion battery electrolyte.

[0049] Taking the preparation of 1L electrolyte as an example, the preparation method is as follows: First, dissolve 2 mol of zinc trifluoromethanesulfonate in deionized water and mix. Then add 4g of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane and 10mL of concentrated nitric acid (accounting for 1% of the total volume of the aqueous zinc-ion battery electrolyte). Stir until a colorless and transparent solution is formed. Finally, transfer it to a 1L volumetric flask, dilute it with deionized water and make up to volume. The pH value of the resulting aqueous zinc-ion battery electrolyte is 0.667.

[0050] Comparative Example 1 An aqueous zinc-ion battery electrolyte uses zinc sulfate heptahydrate as the zinc salt and deionized water as the solvent to form a zinc sulfate electrolyte system.

[0051] Taking the preparation of 1L electrolyte as an example, the preparation method is as follows: Dissolve 2mol of zinc sulfate heptahydrate in 800mL of deionized water, stir until it becomes colorless and transparent, and finally transfer it to a 1L volumetric flask, dilute it with deionized water and make up to volume. The pH value of the resulting aqueous zinc-ion battery electrolyte is 3.421.

[0052] Comparative Example 2 The difference from Example 1 is that the additive 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is replaced with an additive with the following structure: .

[0053] Test Example 1 The ionic conductivity of the obtained electrolyte was determined by electrochemical impedance spectroscopy. The test was performed at room temperature using an electrochemical workstation (e.g., CHI760e) between two blocked electrodes (stainless steel), with a frequency range of 1 Hz to 1 MHz and a perturbation voltage of 10 mV. Ionic conductivity (σ, mS·cm) -1 The result is obtained through calculation using Formula 1: σ = L / (Rb × A) (Formula 1) In Formula 1, L is the electrode spacing (cm), Rb is the bulk electrolyte resistance (Ω) obtained by fitting the impedance spectrum, and A is the electrode area (cm²). 2 ).

[0054] The results are shown in Table 1.

[0055] Table 1 Ionic conductivity of the electrolyte

[0056] Test Example 2 Electrochemical Testing: The electrochemical performance of Zn||Zn symmetric cells and Zn||Cu half-cells was evaluated in air and at room temperature using a CR2032 coin cell on the Xinwei Battery Testing System. Symmetric cells were assembled by sandwiching a glass fiber filter between two zinc foils (Φ14 mm, 15 µm, or 50 µm) containing the electrolytes of Example 1 and Comparative Example 1. Coulombic efficiency was determined using the Zn||Cu half-cell; rate performance and cycle performance were tested using the Zn||Zn symmetric cell.

[0057] Figure 1 Optical photographs taken after immersing the zinc anode in the electrolytes obtained in Comparative Example 1 and Example 1 for three days. Figure 1It can be seen that after the zinc anode was immersed in the electrolyte of Example 1 for three days, a protective film visible to the naked eye was formed on its surface. However, after being immersed in the electrolyte of Comparative Example 1 for three days, no film appeared on the surface, but obvious corrosion marks appeared. This indicates that the electrolyte provided by the present invention can promote the formation of a protective film on the surface of the zinc anode that can prevent corrosion by strong acid electrolyte.

[0058] Figure 2 To test the Zn||Cu half-cell constructed using the electrolytes obtained in Comparative Example 1 and Example 1 at 25°C and 1 mA·cm⁻¹ -2 The following is a graph showing the Coulomb efficiency test results. Figure 2 It can be seen that the Zn||Cu half-cell assembled using the electrolyte of Example 1 exhibits good stability and reversibility during long-term cycling, with a coulombic efficiency close to 100%. In contrast, the Zn||Zn symmetric cell assembled using the electrolyte of Comparative Example 1 shows significant fluctuations during cycling, indicating that its stability and reversibility are poor.

[0059] Figure 3 To test the Zn||Zn symmetric cells constructed using the electrolytes obtained in Comparative Example 1 and Example 1 at 25°C and 1 mAh·cm⁻¹ -2 The following is a graph showing the results of the magnification test. Figure 3 It can be seen that the Zn||Zn symmetrical batteries assembled using the electrolyte of Example 1 have good symmetry in charge-discharge curves under different current densities and high polarization voltage symmetry, indicating that they have good stability and reversibility. In contrast, the Zn||Zn symmetrical batteries assembled using the electrolyte of Comparative Example 1 have poor symmetry in charge-discharge curves under different current densities and asymmetrical polarization voltage, indicating poor stability and reversibility.

[0060] Figure 4 To test the Zn||Zn symmetric cells constructed using the electrolytes obtained in Comparative Example 1 and Example 1 at 25°C and 1 mA·cm⁻¹ -2 1mAh·cm -2 The following is a graph showing the results of the loop test. Figure 4 It can be seen that the Zn||Zn symmetric battery assembled using the electrolyte of Example 1 can operate for 6000 hours, while the Zn||Zn symmetric battery assembled using the electrolyte of Comparative Example 1 can only operate for less than 200 hours. This fully demonstrates that the electrolyte of the present invention can maintain the zinc anode from corrosion under strong acid conditions and exhibits extremely excellent electrochemical cycle stability.

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An aqueous zinc-ion battery electrolyte, characterized in that, It consists of the following components: Water-soluble zinc salts, additives, inorganic acids, and water; In the aqueous zinc-ion battery electrolyte, the concentration of water-soluble zinc salt is 1~2.5 mol / L, and the concentration of additives is 1~6 g / L; The additive is 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane, and the structure of 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacosane is shown in Formula 1: Formula 1; The pH value of the aqueous zinc-ion battery electrolyte is less than or equal to 1; The inorganic acid is concentrated nitric acid, the concentration of which is 68 wt%, and the volume content of concentrated nitric acid in the aqueous zinc-ion battery electrolyte is 0.5-3%.

2. The aqueous zinc-ion battery electrolyte according to claim 1, characterized in that, The water-soluble zinc salt is one or more of zinc sulfate, zinc gluconate, zinc acetate, and zinc trifluoromethanesulfonate.

3. The aqueous zinc-ion battery electrolyte according to claim 1, characterized in that, The water is deionized water.

4. The method for preparing the aqueous zinc-ion battery electrolyte according to any one of claims 1 to 3, characterized in that, Includes the following steps: A zinc salt solution is obtained by mixing water-soluble zinc salt with water. The zinc salt solution and additives are mixed, the pH value is adjusted, and the volume is brought to a final consistency to obtain the aqueous zinc-ion battery electrolyte.

5. An aqueous zinc-ion battery, characterized in that, Includes an electrolyte, wherein the electrolyte is the aqueous zinc-ion battery electrolyte according to any one of claims 1 to 3 or the aqueous zinc-ion battery electrolyte prepared by the preparation method according to claim 4.

6. The aqueous zinc-ion battery according to claim 5, characterized in that, The aqueous zinc-ion battery also includes a positive electrode material, a negative electrode material, and a separator.

7. The aqueous zinc-ion battery according to claim 6, characterized in that, The cathode material includes one or more of manganese-based oxides, vanadium-based oxides, and Prussian blue analogues.

8. The aqueous zinc-ion battery according to claim 6, characterized in that, The negative electrode material includes one or more of zinc foil, zinc alloy, and carbon materials.

9. The aqueous zinc-ion battery according to claim 6, characterized in that, The diaphragm is one or more of glass fiber diaphragm, polypropylene diaphragm, and cellulose diaphragm.

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