Multi-solvent high-entropy electrolyte of aqueous zinc ion battery as well as preparation method and application of multi-solvent high-entropy electrolyte

Abstract

The invention provides a multi-solvent high-entropy electrolyte of an aqueous zinc ion battery as well as a preparation method and application of the multi-solvent high-entropy electrolyte, and belongs to the technical field of aqueous zinc ion batteries. The multi-solvent high-entropy electrolyte provided by the invention is obtained by adding a multi-solvent additive comprising dimethyl sulfoxide, N-methyl pyrrolidone and formamide into a zinc salt solution. According to the high-entropy complex system composed of the multiple solvent additives, it can be guaranteed that all components in the electrolyte can be evenly mixed to form a highly disordered structure, the problems of phase separation, local high concentration and the like can be solved, and therefore the stability of the electrolyte is enhanced. According to the multi-solvent high-entropy electrolyte, the electrochemical performance of the aqueous zinc ion battery is improved, meanwhile, the side reaction of a zinc negative electrode can be effectively inhibited, and the multi-solvent high-entropy electrolyte has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of aqueous zinc-ion battery technology, specifically to a multi-solvent high-entropy electrolyte for aqueous zinc-ion batteries, its preparation method, and its application. Background Technology

[0002] With the rapid advancement of global industrial development, the application of electronic and electrical equipment has gradually become a focus. Batteries, as core components of electrical equipment, now occupy an important place in mobile electronic devices, new energy storage, aerospace, and other industrial technologies, as well as in daily life. Among these, rechargeable batteries are the most widely used.

[0003] Secondary batteries, also known as rechargeable batteries, are recyclable batteries characterized by their ability to be charged and discharged multiple times and their long service life. Traditional secondary batteries include lead-acid batteries, lithium-ion batteries, and nickel-cadmium batteries, but these types of batteries typically have drawbacks such as environmental pollution, safety hazards, high cost, and complex production technology. Aqueous zinc-ion batteries, due to their high safety, high theoretical capacity, wide range of redox potentials, and low production cost, have become a major research focus in the field of secondary batteries. While possessing these advantages, aqueous zinc-ion batteries also suffer from significant drawbacks such as zinc dendrite formation on the zinc anode, hydrogen evolution reaction (HER), and zinc corrosion. Currently, existing technologies address these drawbacks through methods such as anode structure optimization, surface crystal orientation modification, and separator modification. However, the widespread application of these methods requires addressing the secondary pollution, significant cost increases, and unsatisfactory improvement effects, thus limiting their practical value.

[0004] Currently, electrolyte regulation is an effective strategy with high application value and promising prospects. It offers high flexibility and operability, is the most direct solution, and has minimal impact on the environment and cost, aligning with national green development policies. The close contact between the electrolyte and the zinc anode is a direct cause of anolyte interface (AEI) problems. Electrolyte regulation, through the addition of electrolyte additive ions or groups, induces Zn... 2+ Uniform deposition of electrolytes, thereby suppressing the growth of zinc dendrites and other side reactions, is an important means to improve the electrochemical performance of zinc-ion batteries. However, electrolyte regulation also has potential problems, such as high viscosity and low ionic conductivity leading to battery polarization, which in turn reduces battery performance.

[0005] High-entropy electrolytes (HE electrolytes), due to their diverse and complex solutes, can form a highly disordered solvent shell. They can also disrupt the hydrogen bond network of water, thereby strengthening the system's hydrogen bonds and inhibiting the movement of free water, making them ideal for regulating electrolytes in aqueous zinc-ion batteries. Multi-solvent additives, due to their more efficient synergistic effects and their ability to address different AEI (autocorrelation-induced electrochemical inertia) issues, and their ability to be uniformly dispersed through simple mixing without complex dispersion equipment or special pretreatment, can form highly disordered and stable multi-solvent high-entropy electrolytes to improve the electrochemical performance of zinc-ion batteries. However, due to the complex composition of high-entropy electrolytes, their application in regulating electrochemical performance is still in the research stage. Furthermore, problems such as zinc dendrite formation, HER, zinc corrosion, and a significant decrease in ionic conductivity still exist during the regulation of zinc-ion batteries using high-entropy electrolytes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a multi-solvent high-entropy electrolyte for aqueous zinc-ion batteries, its preparation method, and its application, thereby solving problems such as zinc dendrite formation, hydrogen evolution reaction, and corrosion at the zinc anode in aqueous zinc-ion batteries. The multi-solvent additive of this invention is more efficient due to the synergistic effect of its multiple components, simultaneously addressing different AEI (autogenous electrolysis) issues, and can be uniformly dispersed through simple mixing, requiring no complex dispersion equipment or special pretreatment.

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

[0008] In a first aspect, the present invention provides a multi-solvent high-entropy electrolyte (DNF-E) for an aqueous zinc-ion battery, which is obtained by adding a multi-solvent additive (DNF) to a zinc salt solution; wherein the multi-solvent additive includes dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) and formamide (FA).

[0009] To address the defects of zinc anodes in aqueous zinc-ion batteries, such as zinc dendrite formation, hydrogen evolution reaction (HER), and corrosion, this invention utilizes a multi-solvent additive formed from a specific ratio of dimethyl sulfoxide (DMSO), N-methylpyrrolidone (N-methylpyrrolidone), and formamide to create a highly disordered yet stable multi-solvent high-entropy electrolyte. This electrolyte effectively suppresses zinc dendrite formation, HER, and zinc corrosion at the anode, while significantly improving ionic conductivity. It reduces pollution and mitigates risks at a lower cost, inhibiting zinc dendrite growth and self-discharge. Furthermore, this multi-solvent high-entropy electrolyte is compatible with lead-acid battery production lines, suitable for 48V communication base stations, and can also be applied to other zinc anode batteries such as zinc-bromine flow batteries. Specifically, this invention optimizes the anode working environment by adding a multi-solvent additive comprising a specific ratio of DMSO, N-methylpyrrolidone, and formamide to the traditional electrolyte; wherein, N-methylpyrrolidone contributes to the Zn... 2+Solvation-induced structural remodeling reduces the formation of hydrated zinc ions; furthermore, both dimethyl sulfoxide and N-methylpyrrolidone possess weak solvation properties, which can synergistically regulate Zn. 2+ The diffusion of N-methylpyrrolidone promotes the uniform deposition and detachment of zinc ions. The carbonyl oxygen and amino nitrogen of N-methylpyrrolidone form hydrogen bonds with water molecules, enhancing the stability of the hydrogen bond network structure, reducing the activity of free water, decreasing the possibility of hydrogen evolution reaction on the zinc anode surface, inhibiting zinc dendrite growth, and improving the electrolyte's antifreeze properties and ionic conductivity. This high-entropy complex system composed of multiple solvent additives not only ensures uniform mixing of components in the electrolyte, forming a highly disordered structure, but also prevents phase separation and localized high concentrations, thus enhancing electrolyte stability. Its application in aqueous zinc-ion batteries can improve the electrochemical performance of these batteries while effectively suppressing side reactions at the zinc anode, demonstrating promising application prospects.

[0010] Furthermore, the volume ratio of dimethyl sulfoxide, N-methylpyrrolidone and formamide is (1~5):(2~6):(3~8).

[0011] Furthermore, the amount of the multi-solvent additive added is 0.01% to 0.10% of the mass of the zinc salt solution.

[0012] Furthermore, the concentration of the zinc salt solution is 1.9~2.2 mol·L⁻¹. -1 .

[0013] Furthermore, the zinc salt includes zinc sulfate (ZnSO4).

[0014] Secondly, the present invention provides a method for preparing the multi-solvent high-entropy electrolyte as follows: dimethyl sulfoxide, N-methylpyrrolidone and formamide are mixed in a volume ratio, and stirred using a magnetic stirrer at 60~120 r·min. -1 Stir at a high speed for 30-60 min to ensure homogeneity, obtaining a multi-solvent additive; add the multi-solvent additive to a zinc salt solution and stir with a magnetic stirrer at 60-120 r·min. -1 Stir at a high speed for 30-60 minutes to ensure uniform mixing and obtain a multi-solvent high-entropy electrolyte.

[0015] Thirdly, the present invention provides the application of the multi-solvent high-entropy electrolyte in the preparation of aqueous zinc-ion batteries.

[0016] Fourthly, the present invention provides an aqueous zinc-ion battery, comprising the aforementioned multi-solvent high-entropy electrolyte.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] 1. This invention optimizes the negative electrode working environment by adding a multi-solvent additive containing a specific ratio of dimethyl sulfoxide, N-methylpyrrolidone, and formamide to a traditional electrolyte; wherein, N-methylpyrrolidone helps Zn 2+ Solvation-induced structural remodeling reduces the formation of hydrated zinc ions; furthermore, both dimethyl sulfoxide and N-methylpyrrolidone possess weak solvation properties, which can synergistically regulate Zn. 2+ The diffusion of the electrolyte promotes the uniform deposition and detachment of zinc ions. N-methylpyrrolidone forms hydrogen bonds with the carbonyl oxygen and amino nitrogen of formamide and water molecules, enhancing the stability of the hydrogen bond network structure, reducing the activity of free water, decreasing the possibility of hydrogen evolution reaction (HER) on the negative electrode surface, inhibiting the growth of zinc dendrites, and improving the electrolyte's antifreeze properties and ionic conductivity. Applying this multi-solvent high-entropy electrolyte to aqueous zinc-ion batteries can inhibit the growth of zinc dendrites on the zinc negative electrode and the occurrence of the HER reaction, achieving excellent electrochemical stability at the electrode / electrolyte interface, thereby extending battery cycle life and increasing battery lifespan.

[0019] 2. The multi-solvent high-entropy electrolyte provided by this invention solves the problem of low ionic conductivity of traditional electrolytes. When applied to aqueous zinc-ion batteries, it can significantly improve ionic conductivity and reduce polarization voltage, thereby significantly extending the battery's cycle stability and cycle life.

[0020] 3. The method of regulating the electrochemical performance of batteries in this invention does not require chemical reactions or special conditions. It only requires solution preparation under normal temperature and pressure conditions to obtain the multi-solvent high-entropy electrolyte of this invention. Compared with other methods for regulating battery defects, the method of this invention is simple to operate, requires less space for production, and is more conducive to industrial development. Attached Figure Description

[0021] Figure 1 The Fourier transform infrared (FTIR) and Raman spectra of DNF-E and ordinary zinc sulfate solution in Example 1 are shown below; Figure 1 a is the Fourier transform infrared spectrum of DNF-E and ordinary zinc sulfate solution; Figure 1 b is the Raman spectrum of DNF-E and ordinary zinc sulfate solution;

[0022] Figure 2 The Zn / / Zn symmetric cell of Embodiment 1 of the present invention is at 10 mA·cm -2 Electrochemical performance test results at current density; among which, Figure 2 a represents the cycle test results of DNF-E@Zn / / Zn symmetric cells and ordinary Zn / / Zn symmetric cells; Figure 2 b represents the charge-discharge curves of the DNF-E@Zn / / Zn symmetrical battery at different cycles; Figure 2c represents the charge-discharge curves of a typical Zn / / Zn symmetrical battery with different numbers of cycles;

[0023] Figure 3 The Zn / / Cu half-cell of Example 1 of this invention is measured at 10 mA·cm⁻¹. -2 Electrochemical performance test results at current density; among which, Figure 3 a is a graph showing the cycle performance and coulombic efficiency of the DNF-E@Zn / / Cu half-cell and the ordinary Zn / / Cu half-cell; Figure 3 b represents the charge-discharge curves of the DNF-E@Zn / / Cu half-cell at different cycles; Figure 3 c represents the charge-discharge curves of a typical Zn / / Cu half-cell at different numbers of cycles;

[0024] Figure 4 (NH4) is from Embodiment 1 of the present invention. X VO3 / / Zn (full cell, ordinary (NH4)) X VO3 / / Zn full cell and comparative examples 1-3: DN-E@(NH4) X VO3 / / Zn full battery, DF-E@(NH4) X VO3 / / Zn full battery, NF-E@(NH4) X VO3 / / Zn full cell at 10 mA·cm -2 Electrochemical performance test results at current density; among which, Figure 4 a is DNF-E@(NH4) X VO3 / / Zn (full cell, ordinary (NH4)) X VO3 / / Zn full cell, DN-E@(NH4) X VO3 / / Zn full battery, DF-E@(NH4) X VO3 / / Zn full battery, NF-E@(NH4) X Cyclic performance test results of VO3 / / Zn full cells; Figure 4 b is DNF-E@(NH4) X Charge-discharge curves of a VO3 / / Zn full cell at different charge / discharge cycles; Figure 4 c represents ordinary (NH4) X Charge-discharge curves of a VO3 / / Zn full cell at different charge / discharge cycles; Figure 4 d represents DN-E@(NH4) X Charge-discharge curves of a VO3 / / Zn full cell at different charge / discharge cycles; Figure 4 e represents DF-E@(NH4) X Charge-discharge curves of a VO3 / / Zn full cell at different charge / discharge cycles; Figure 4 f represents NF-E@(NH4) X Charge-discharge curves of a VO3 / / Zn full cell at different charge / discharge cycles;

[0025] Figure 5 This refers to DNF-E@(NH4) in Embodiment 1 of the present invention. X CV plots of a full VO3 / / Zn cell at different scan rates;

[0026] Figure 6 To combine 3 DNF-E@(NH4) X Image of an LED light powered by a series connection of VO3 / Zn batteries;

[0027] Figure 7 To combine 3 DNF-E@(NH4) X Voltage test results of a VO3 / / Zn full cell in series;

[0028] Figure 8 The images show actual pictures of DNF-E, ordinary zinc sulfate, DF-E, DN-E, and NF-E prepared in Example 1 of this invention. Detailed Implementation

[0029] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a multi-solvent high-entropy electrolyte (DNF-E) for aqueous zinc-ion batteries, which is obtained by adding a multi-solvent additive (DNF) to a zinc salt solution; wherein the multi-solvent additive includes dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) and formamide (FA).

[0031] In some examples, the volume ratio of the dimethyl sulfoxide, N-methylpyrrolidone and formamide is (1~5):(2~6):(3~8).

[0032] In some examples, the amount of the multi-solvent additive added is 0.01% to 0.10% of the mass of the zinc salt solution.

[0033] In some examples, the concentration of the zinc salt solution is 1.9–2.2 mol·L⁻¹. -1 .

[0034] In some examples, the preparation method of the multi-solvent high-entropy electrolyte is as follows: dimethyl sulfoxide, N-methylpyrrolidone and formamide are mixed in a volume ratio, and stirred with a magnetic stirrer at 60~120 r·min. -1Stir at a high speed for 30-60 minutes to ensure homogeneity, obtaining a multi-solvent additive; add the multi-solvent additive to the zinc salt solution and stir with a magnetic stirrer at 60-120 r·min. -1 Stir at a high speed for 30-60 minutes to ensure uniform mixing and obtain a multi-solvent high-entropy electrolyte.

[0035] Example 1: An aqueous zinc-ion battery

[0036] 1. Formulation of multi-solvent additives (DNF)

[0037] DMSO, NMP, and FA were weighed out in a volume ratio of 2:3:5 and placed in a beaker. The mixture was stirred with a magnetic stirrer at 65 r·min. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing and obtain DNF.

[0038] 2. Preparation of multi-solvent high-entropy electrolyte (DNF-E)

[0039] Weigh 11.5 g of ZnSO4·7H2O solid and dissolve it in 20 mL of deionized water to obtain a 2 M ZnSO4 solution, i.e., a common zinc sulfate solution. Add the DNF prepared in step (1) to the ZnSO4 solution, the amount of which is 0.07% of the mass of the zinc sulfate solution. Stir at 65 r·min at 25 °C using a magnetic stirrer. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain DNF-E. See the actual product image. Figure 8 .

[0040] 3. Characterization of multi-solvent high-entropy electrolyte (DNF-E)

[0041] The DNF-E prepared in this embodiment was subjected to Fourier transform infrared spectroscopy and Raman spectroscopy tests with a common zinc sulfate solution. The results are shown in [Figure number missing]. Figure 1 .

[0042] Figure 1 Fourier transform infrared spectroscopy results of a showed that DNF-E interacts with ordinary zinc sulfate through the five chemical bonds C=O, HOH, S=O, OH, and NH, and SO42-. 2- The absorption peaks of DNF-E and ordinary zinc sulfate are observed at 1080 cm⁻¹. -1 The peaks at each location are all composed of SO4 2- Formation of internal chemical bond stretching vibrations; 3300 cm -1 The peaks at 1600 cm⁻¹ are all formed by the stretching vibrations of OH bonds; -1 The peaks at these locations are all formed by the bending vibrations of HOH bonds, which is related to water and SO4. 2- Ion-related. DNF-E at 1050 cm⁻¹ -1The peak at 1660 cm⁻¹ is formed by the stretching vibration of the S=O bond, which is related to the presence of DMSO. -1 The formation at 3350 cm⁻¹ is due to the stretching vibration of the C=O bond, which is related to the presence of NMP and FA. -1 The peak at that point is formed by the stretching vibration of the NH bond, which is related to the presence of FA. Figure 1 Raman spectroscopy results showed that DNF-E interacts with ordinary zinc sulfate through the four chemical bonds C, OH, NH, and S=O, and SO42-. 2- The absorption peaks of DNF-E and ordinary zinc sulfate are at 980 cm⁻¹. -1 The peaks at each location are all composed of SO4 2- Formation of internal chemical bond stretching vibrations; 3500 cm -1 The peaks at 1050 cm⁻¹ are all formed by the stretching vibration of OH bonds, which is related to the water content; DNF-E at 1050 cm⁻¹... -1 The peak at 1300 cm⁻¹ is formed by the stretching vibration of the S=O bond, which is related to its DMSO content; -1 The peak at 3350 cm⁻¹ is formed by the stretching vibration of the C-C bonds within the ring, which is related to its NMP content; -1 The peak at this point is formed by the stretching vibration of the NH bond, which is related to its FA content. The addition of DMSO alters the solvation structure of zinc ions, promoting the formation of more diverse solvation layers and inhibiting the formation of hydrated zinc ions, thereby suppressing HER. DMSO and NMP can synergistically regulate Zn. 2+ The diffusion of NMP promotes uniform deposition and exfoliation, inhibiting the growth of zinc dendrites; the use of NMP and FA can enhance the hydrogen bond network of the system, reduce the activity of free water, thereby reducing the proportion of free water at the negative electrode interface and inhibiting the occurrence of HER.

[0043] 4. Battery material preparation

[0044] (NH4) X VO3 cathode material: Weigh 2.34 g of ammonium metavanadate and dissolve it in 250 mL of deionized water at 70℃. After dissolution, add 10 mmol of thiourea, and slowly add dilute sulfuric acid dropwise until the pH is less than 2. Stir at 70℃ for 60 min, then raise the temperature to 90℃ and continue stirring for 2.5 h. Wash the resulting product with distilled water and anhydrous ethanol, and dry to obtain the cathode material (NH4). X VO3. The cathode material (NH4) X VO3, acetylene black, and polyvinylidene fluoride (PVDF) were mixed and ground into a fine powder at a mass ratio of 7:2:1. The powder was dissolved using NMP to obtain a slurry. The resulting slightly viscous slurry was coated onto carbon paper, dried, and punched into sheets with a diameter of 12 mm to obtain (NH4). X VO3 positive electrode tablets.

[0045] Preparation of other materials: Several zinc sheets with diameters of 12 mm and 15 mm, copper sheets with diameters of 12 mm, and diaphragms with diameters of 16 mm were punched out using a punching machine.

[0046] 5. Assemble an aqueous zinc-ion battery

[0047] Assemble the battery in the following order: negative electrode shell (model 2025), zinc sheet, separator, electrolyte, positive electrode sheet, gasket, spring, and positive electrode shell (model 2025). Place the battery into a button cell sealing machine and press it tightly. The battery assembled in this embodiment is as follows:

[0048] 6. Performance testing of aqueous zinc-ion batteries

[0049] 6.1 Zn / / Zn symmetric cell

[0050] The Zn / / Zn symmetric cell was tested using a blue electric field testing system at 10 mA·cm⁻¹. -2 Under the specified current density, constant current charge-discharge tests were conducted in the following sequence: rest, constant current charging, rest, and constant current discharging. The rest time was 30 seconds for each test, and the constant current charging and discharging times were 0.1 hours for each test. The test results are as follows: Figure 2 As shown. By Figure 2 As can be seen from a, under the same test conditions, the DNF-E@Zn / / Zn symmetric battery exhibits a lower polarization voltage than the ordinary Zn / / Zn symmetric battery during charge-discharge cycles of 1~2 h and 598~600 h, indicating that the Zn / / Zn symmetric battery using the multi-solvent high-entropy electrolyte of this invention possesses better cycle stability. Figure 2 b、 Figure 2 As can be seen from c, the polarization voltage of the DNF-E@Zn / / Zn symmetric cell is 88 mV, which is significantly lower than the 110 mV of the ordinary Zn / / Zn symmetric cell. Furthermore, the overpotential change of the DNF-E@Zn / / Zn symmetric cell is small, exhibiting stable cycling performance. This indicates that the DNF-E@Zn / / Zn symmetric cell using the multi-solvent high-entropy electrolyte of this invention can significantly suppress the growth of zinc dendrites and the hydrogen evolution reaction.

[0051] 6.2 Zn / / Cu half-cell

[0052] The Zn / / Cu half-cell was tested using a blue electric field testing system at 10 mA·cm⁻¹. -2 Under the specified current density, constant current charge-discharge tests were conducted in the following sequence: rest, constant current charging, rest, and constant current discharging. The rest time was 30 seconds for each test, and the constant current charging and discharging times were 0.1 hours for each test. The test results are as follows: Figure 3 As shown. By Figure 3As can be seen from a, under the same test conditions, the DNF-E@Zn / / Cu half-cell exhibits stable cycle performance, and its coulombic efficiency consistently remains around 100%. Figure 3 b、 Figure 3 As can be seen from c, the polarization voltage of the DNF-E@Zn / / Cu half-cell (92 mV) is smaller than that of the ordinary Zn / / Cu half-cell (102 mV), and the DNF-E@Zn / / Cu half-cell has a narrower electrochemical stability window, resulting in a smoother capacity plateau and the ability to induce Zn... 2+ Uniform deposition or stripping. The above results indicate that the DNF-E@Zn / / Cu half-cell using the multi-solvent high-entropy electrolyte of this invention achieves the goal of reducing zinc dendrite growth on the negative electrode surface.

[0053] 6.3 (NH4) X VO3 / / Zn full battery

[0054] (NH4) X The VO3 / Zn full cell was tested on the Blue Electricity testing system at 10 mA·cm⁻¹. -2 Under a current density of [value missing], constant current charge-discharge tests were conducted, following the sequence of rest, constant current charging, rest, and constant current discharging. The resting time was 30 s for each test, and the constant current charging and discharging times were 0.1 h for each. The test results are as follows: Figure 4 As shown in Table 1. From Figure 4 As shown in a and Table 1, DNF-E@(NH4) X After 200 cycles of the VO3 / Zn full battery, the remaining specific capacity is 155.6 mAh·g. -1 , while ordinary (NH4) X The VO3 / Zn battery has only 100.5 mAh·g remaining. -1 This demonstrates that the introduction of specific multi-solvent additives into the electrolyte in this invention enables DNF-E@(NH4) to... X VO3 / / Zn full cells exhibit high cycle stability and specific capacity. Figure 4 b、 Figure 4 From c, we can know that DNF-E@(NH4) X Voltage curves of VO3 / / Zn full cells at different cycle numbers compared to ordinary (NH4) cells. X VO3 / / Zn full cells have a more pronounced charge and discharge plateau, and the plateau decay rate changes more slowly with increasing cycle number, while the polarization voltage remains relatively low.

[0055] For DNF-E@(NH4) X CV tests were performed on VO3 / / Zn full cells, with scan rates set from 1 to 10 mV·s. -1 Take a portion of the scan rate, and the result is as follows: Figure 5 As shown in the figure, the peak current levels out gradually with increasing scan rate, and the curves corresponding to the oxidation / reduction peaks exhibit high symmetry, stable peak positions, and low separation, indicating that the battery has high conductivity, high reversibility, and low internal resistance. Even at high scan rates, the capacity remains good, demonstrating that the multi-solvent high-entropy electrolyte of this invention is beneficial for enhancing ionic conductivity. These results prove that introducing specific multi-solvent additives into the electrolyte can accelerate the migration of zinc ions in the solution and has advantages such as high reversibility of interfacial reactions, suppression of battery self-discharge, reduction of corrosion current, and increase of corrosion potential.

[0056] Three DNF-E@(NH4) X A VO3 / / Zn full battery was connected in series. The test was conducted to see if it could light an LED after charging, and its voltage was measured. The results are as follows: Figure 6 , Figure 7 As shown, the DNF-E@(NH4) of the present invention X The VO3 / Zn full cell can be charged and discharged normally, and the three DNF-E@(NH4) batteries... X The voltage of a VO3 / Zn battery connected in series is 4.919 V, which is sufficient to power an LED light.

[0057] Example 2: A multi-solvent high-entropy electrolyte

[0058] 1. Formulation of multi-solvent additives (DNF)

[0059] DMSO, NMP, and FA were weighed out in a volume ratio of 2:3:5 and placed in a beaker. The mixture was stirred with a magnetic stirrer at 120 r·min. -1 Stir at a certain speed for 60 minutes to ensure uniform mixing and obtain DNF.

[0060] 2. Preparation of multi-solvent high-entropy electrolyte (DNF-E)

[0061] Weigh 11.5 g of ZnSO4·7H2O solid and dissolve it in 20 mL of deionized water to obtain a 2 M ZnSO4 solution. Add the DNF prepared in step (1) to the ZnSO4 solution, the amount of which is 0.07% of the mass of the zinc sulfate solution. Stir at 120 r·min using a magnetic stirrer at 25 °C. -1 Stir at a certain speed for 60 minutes to ensure uniform mixing and obtain DNF-E.

[0062] Example 3: An aqueous zinc-ion battery

[0063] The aqueous zinc-ion battery in this embodiment is basically the same as that in Embodiment 1, except that it is assembled with a Zn / / Zn symmetric cell, a Zn / / Cu half-cell, and (NH4). XThe standard specification model of VO3 / / Zn full cell is 2032, and the positive and negative electrode shells used are also model 2032.

[0064] Example 4: A multi-solvent high-entropy electrolyte

[0065] 1. Formulation of multi-solvent additives (DNF)

[0066] DMSO, NMP, and FA were weighed out in a volume ratio of 2:3:5 and placed in a beaker. The mixture was stirred with a magnetic stirrer at 65 r·min. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing and obtain DNF.

[0067] 2. Preparation of multi-solvent high-entropy electrolyte (DNF-E)

[0068] Weigh 11.5 g of ZnSO4·7H2O solid and dissolve it in 20 mL of deionized water to obtain a 2 M ZnSO4 solution. Add the DNF prepared in step (1) to the ZnSO4 solution, the amount of which is 0.04% of the mass of the zinc sulfate solution. Stir at 65 r·min using a magnetic stirrer at 30 °C. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain DNF-E.

[0069] Comparative Example 1: An aqueous zinc-ion battery

[0070] (1) Weigh DMSO and NMP in a volume ratio of 2:3 and place them in a beaker. Stir with a magnetic stirrer at 65 r·min. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain DN.

[0071] (2) Weigh 11.5 g of ZnSO4·7H2O solid and dissolve it in 20 mL of deionized water to obtain a ZnSO4 solution with a concentration of 2 M. Add the DN prepared in step (1) to the ZnSO4 solution, the amount of which is 0.07% of the mass of the zinc sulfate solution. Stir at 65 r·min using a magnetic stirrer at 25 °C. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain DN-E. See the actual product image. Figure 8 .

[0072] (3) In the order of negative electrode shell, zinc sheet, separator, electrolyte, positive electrode sheet, gasket, spring sheet, and positive electrode shell of model 2025, (NH4) X DN-E@(NH4) is assembled using a VO3 positive electrode and a 15 mm zinc sheet as the negative electrode. X VO3 / / Zn full battery.

[0073] (4) Add DN-E@(NH4)X The VO3 / Zn full cell was tested on the Blue Electricity testing system at 10 mA·cm⁻¹. -2 Under a current density of [value missing], constant current charge-discharge tests were conducted, following the sequence of rest, constant current charging, rest, and constant current discharging. The resting time was 30 s for each test, and the constant current charging and discharging times were 0.1 h for each. The test results are as follows: Figure 4 As shown in Table 1. From Figure 4 As shown in d and Table 1, DN-E@(NH4) X After 200 cycles of the VO3 / Zn full battery, the remaining specific capacity is 119.9 mAh·g. -1 .

[0074] Comparative Example 2: An Aqueous Zinc-Ion Battery

[0075] (1) Weigh DMSO and FA in a volume ratio of 2:5 and place them in a beaker. Stir with a magnetic stirrer at 65 r·min. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain DF.

[0076] (2) Weigh 11.5 g of ZnSO4·7H2O solid and dissolve it in 20 mL of deionized water to obtain a ZnSO4 solution with a concentration of 2 M. Add the DF prepared in step (1) to the ZnSO4 solution, the amount of which is 0.07% of the mass of the zinc sulfate solution. Stir at 65 r·min using a magnetic stirrer at 25 °C. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain DF-E. See the actual product image. Figure 8 .

[0077] (3) In the order of negative electrode shell, zinc sheet, separator, electrolyte, positive electrode sheet, gasket, spring sheet, and positive electrode shell of model 2025, (NH4) X DF-E@(NH4) is assembled using a VO3 positive electrode and a 15 mm zinc sheet as the negative electrode. X VO3 / / Zn full battery.

[0078] (4) DF-E@(NH4) X The VO3 / Zn full cell was tested on the Blue Electricity testing system at 10 mA·cm⁻¹. -2 Under a current density of [value missing], constant current charge-discharge tests were conducted, following the sequence of rest, constant current charging, rest, and constant current discharging. The resting time was 30 s for each test, and the constant current charging and discharging times were 0.1 h for each. The test results are as follows: Figure 4 As shown in Table 1. From Figure 4 As shown in e and Table 1, DF-E@(NH4) X After 200 cycles of the VO3 / Zn full battery, the remaining specific capacity is 106.6 mAh·g.-1 .

[0079] Comparative Example 3: An Aqueous Zinc-Ion Battery

[0080] (1) Weigh NMP and FA in a volume ratio of 3:5 and place them in a beaker. Stir with a magnetic stirrer at 65 r·min. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain NF.

[0081] (2) Weigh 11.5 g of ZnSO4·7H2O solid and dissolve it in 20 mL of deionized water to obtain a ZnSO4 solution with a concentration of 2 M. Add the NF prepared in step (1) to the ZnSO4 solution, the amount of which is 0.07% of the mass of the zinc sulfate solution. Stir at 65 r·min using a magnetic stirrer at 25 °C. -1 Stir at a certain speed for 30 minutes to ensure uniform mixing, and obtain NF-E. See the actual product image. Figure 8 .

[0082] (3) In the order of negative electrode shell, zinc sheet, separator, electrolyte, positive electrode sheet, gasket, spring sheet, and positive electrode shell of model 2025, (NH4) X NF-E@(NH4) is assembled using a VO3 positive electrode and a 15 mm zinc sheet as the negative electrode. X VO3 / / Zn full battery.

[0083] (4) Add NF-E@(NH4) X The VO3 / Zn full cell was tested on the Blue Electricity testing system at 10 mA·cm⁻¹. -2 Under a current density of [value missing], constant current charge-discharge tests were conducted, following the sequence of rest, constant current charging, rest, and constant current discharging. The resting time was 30 s for each test, and the constant current charging and discharging times were 0.1 h for each. The test results are as follows: Figure 4 As shown in Table 1. From Figure 4 As shown in f and Table 1, NF-E@(NH4) X After 200 cycles of the VO3 / Zn full battery, the remaining specific capacity is 106.6 mAh·g. -1 .

[0084] Table 1: Electrochemical performance test results of the full cells prepared in Example 1 and Comparative Examples 1-3

[0085] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A multi-solvent high-entropy electrolyte for aqueous zinc-ion batteries, characterized in that, It is obtained by adding a multi-solvent additive to a zinc salt solution; wherein the multi-solvent additive includes dimethyl sulfoxide, N-methylpyrrolidone and formamide.

2. The multi-solvent high-entropy electrolyte for an aqueous zinc-ion battery according to claim 1, characterized in that, The volume ratio of dimethyl sulfoxide, N-methylpyrrolidone and formamide is (1~5):(2~6):(3~8).

3. The multi-solvent high-entropy electrolyte for an aqueous zinc-ion battery according to claim 2, characterized in that, The amount of the multi-solvent additive added is 0.01% to 0.10% of the mass of the zinc salt solution.

4. The multi-solvent high-entropy electrolyte for an aqueous zinc-ion battery according to claim 3, characterized in that, The concentration of the zinc salt solution is 1.9~2.2 mol·L⁻¹. -1 .

5. The multi-solvent high-entropy electrolyte for an aqueous zinc-ion battery according to claim 4, characterized in that, The zinc salt includes zinc sulfate.

6. A method for preparing the multi-solvent high-entropy electrolyte for an aqueous zinc-ion battery according to any one of claims 1-5, characterized in that, The process includes the following steps: mixing dimethyl sulfoxide, N-methylpyrrolidone and formamide in a volume ratio to obtain a multi-solvent additive; adding the multi-solvent additive to a zinc salt solution and mixing them evenly to obtain a multi-solvent high-entropy electrolyte.

7. The application of the multi-solvent high-entropy electrolyte of any one of claims 1-5 in the preparation of aqueous zinc-ion batteries.

8. An aqueous zinc-ion battery, characterized in that, Including the multi-solvent high-entropy electrolyte of the aqueous zinc-ion battery according to any one of claims 1-5.

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