Nanocluster gel electrolyte and application

Abstract

The invention relates to the technical field of zinc ion batteries, in particular to a nanocluster colloid electrolyte for stabilizing a zinc anode through double constraint on water and anions and application. The nanocluster gel electrolyte comprises a nano-alumina isopropanol dispersion and a zinc salt solution, the nano-alumina isopropanol dispersion comprises alumina nanoparticles and isopropanol, and the zinc salt solution comprises a solute zinc sulfate and a solvent water. The nanocluster gel electrolyte is used as an electrolyte of an aqueous zinc ion battery. According to the invention, the component design is reasonable, the synthesis steps are simple and uncontrollable, no special treatment is needed, and the obtained product has good cycling stability and reversibility after being prepared into a zinc ion battery; the industrial application is convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc ion batteries, and more particularly to a nanocluster colloidal electrolyte capable of dually constraining water and anions to stabilize a zinc anode and its application. Background Art

[0002] Electrochemical energy storage systems are one of the key technologies to drive the development of energy infrastructure towards clean, sustainable and renewable energy. Lithium-ion batteries currently dominate the secondary energy market due to significant progress in commercialization and are widely used in various fields from portable electronic devices to grid-level energy storage. However, recent safety and cost issues associated with lithium-ion batteries have prompted people to look for more suitable alternatives. Among them, aqueous zinc-ion batteries have attracted much attention due to their superior energy density, low cost, high safety, low environmental impact and abundant zinc resources. Unlike aqueous lithium / sodium / calcium / magnesium ion batteries, aqueous zinc-ion batteries can directly use metallic zinc as the negative electrode. At the same time, metallic zinc has a high theoretical capacity of 820 mAHg in neutral aqueous solution. -1 , and a lower zinc / zinc ion redox potential (-0.76V compared to a standard hydrogen electrode). However, the electrochemical and thermodynamic instability of zinc metal in dilute aqueous solutions has hindered its commercialization. That is, during anode operation, severe dendrite growth, interfacial corrosion, and hydrogen evolution reactions will occur on the zinc anode. These problems lead to uneven zinc deposition and undesirable interfacial side reactions in neutral or weakly acidic electrolytes. These problems continue to occur during the zinc anode cycle, resulting in low coulombic efficiency and poor reversibility, ultimately accelerating battery failure or capacity loss. In the prior art, people have tried to use clay to prepare aqueous zinc-ion battery colloidal electrolytes. For example, patent CN109980302A has developed an aqueous zinc-ion battery colloidal electrolyte with excellent performance, but its cycle performance still has room for further improvement. Summary of the Invention

[0003] To address the aforementioned technical issues with existing zinc anode materials, the present invention provides a nanocluster colloidal electrolyte to produce a stable zinc metal anode. The addition of oxide nanoparticles adsorbs water molecules and captures anions, forming a space charge layer network, accelerating zinc ion kinetics and reducing interfacial resistance. The nanoparticles and isopropyl alcohol components in the colloidal electrolyte not only modify the hydrogen bond network and solvation structure but also adsorb on the zinc anode surface, regulating zinc ion migration and electrodeposition behavior, thereby promoting uniform zinc deposition / dissolution and inhibiting corrosion and hydrogen evolution reactions.

[0004] In order to achieve the above object, the technical solution of the present invention is as follows:

[0005] The invention discloses a nano-cluster colloidal electrolyte, comprising a nano-alumina isopropyl alcohol dispersion and a zinc salt solution. The nano-alumina isopropyl alcohol dispersion comprises aluminum oxide nanoparticles and isopropyl alcohol, and the zinc salt solution comprises zinc sulfate as a solute and water as a solvent.

[0006] Preferably, the present invention provides a nanocluster colloidal electrolyte, which is prepared by uniformly mixing nano-aluminum oxide dispersed in isopropyl alcohol and a zinc salt solution.

[0007] Preferably, the present invention provides a nanocluster colloidal electrolyte, which is prepared by the following process: adding A to the zinc-containing solution in a ratio of 5-30 μl, preferably 5-15 μl, and more preferably 9-11 μl to 8-15 ml, preferably 9-11 ml of zinc-containing solution, and stirring uniformly to obtain a colloidal solution; the A is an isopropanol solution containing nano-alumina particles; in the isopropanol solution containing nano-alumina particles, the solid content of the nano-alumina particles is 2-30wt%, preferably 18-30wt%, and more preferably 19-21wt%; the concentration of zinc in the zinc-containing solution is 0.2-2.5 mol / L, preferably 1.5-2.5 mol / L, and more preferably 1.8-2.2 mol / L.

[0008] Preferably, in the nanocluster colloidal electrolyte of the present invention, the wetting angle between the nanocluster colloidal electrolyte and the zinc anode is 77.5-78.5°.

[0009] After optimization, the present invention provides a nanocluster colloidal electrolyte, the ionic conductivity of the nanocluster colloidal electrolyte is greater than 3.8Sm -1 After further optimization, the present invention is a nanocluster colloidal electrolyte, the ionic conductivity of the nanocluster colloidal electrolyte is 4.0~4.1Sm -1 .

[0010] Preferably, in the nanocluster colloidal electrolyte of the present invention, the particle size of the nano-alumina particles is 10-500 nanometers, preferably 10-100 nanometers, and more preferably 15-25 nanometers.

[0011] Preferably, the present invention provides a nanocluster colloidal electrolyte, wherein 10 μl of nanoalumina (Al2O3(IPA)) dispersed in isopropyl alcohol (the average particle size of the nanoalumina in the nanoalumina solution in isopropyl alcohol is 20 nm, and the solid content of the nanoalumina in the nanoalumina solution in isopropyl alcohol is 20 wt%) is uniformly mixed with 10 ml of ZnSO4 (2 M) electrolyte by ultrasonic treatment to obtain a ZnSO4+Al2O3(IPA nanocluster colloidal electrolyte.

[0012] As a further preference, the zinc-containing solution is selected from at least one of ZnSO4 solution and Zn(OTF) solution. When the amount of nano-alumina is too little, the effect is not obvious, while when it is too much, the colloidal solution is prone to coagulation and the internal resistance increases.

[0013] The present invention provides a nanocluster colloidal electrolyte. The colloidal solution obtained by the preparation method of the present invention exhibits obvious Tyndall effect and has a stability time of more than 8 hours.

[0014] The invention discloses an application of a nanocluster colloidal electrolyte, including using the nanocluster colloidal electrolyte as an electrolyte for an aqueous zinc ion battery.

[0015] The present invention discloses an application of a nanocluster colloidal electrolyte. Two zinc electrodes are assembled into a CR2032 button battery. Whatman GF / D is used as a separator (i.e., Whatman GF / D glass fiber filter paper is used as a separator). The electrolyte is a ZnSO4+Al2O3 nanocluster colloidal electrolyte. The resulting symmetrical battery has a current density of 5 mA cm -2 , areal capacity of 5 mAh cm -2 The test condition stability cycle time is greater than 1000 h.

[0016] The present invention discloses an application of a nanocluster colloidal electrolyte. A zinc negative electrode and a V2O5 positive electrode are assembled into a CR2032 full battery. A Whatman GF / D is used as a separator (i.e., Whatman GF / D glass fiber filter paper is used as a separator). The electrolyte is a ZnSO4+Al2O3 nanocluster colloidal electrolyte. The obtained full battery has a high conductivity at 1 A g -1 The full battery cycle test was carried out under the test conditions, and its initial discharge capacity was 213 mAh g -1 The capacity retention rate is higher than 80% when the cycle reaches 820 cycles.

[0017] Compared with the prior art, the gain effects of the present invention are as follows: (1) The hydroxyl groups on the surface of nano-alumina can change the surface chemical potential, while the hydroxyl groups in isopropyl alcohol can destroy the hydrogen bond network between water molecules. The appropriate concentration and amount of nano-alumina combined with isopropyl alcohol can enhance the bidirectional synergistic effect to the optimal state. This enhanced bidirectional synergistic effect can significantly affect the bonding characteristics, polarization and network structure of the aqueous electrolyte. The appropriate amount of nano-Al2O3 used in the present invention exhibits an intermediate adsorption mechanism in the system. H2O molecules are physically adsorbed on the surface of Al2O3 nanoparticles through hydroxyl groups, and then additional water molecules and SO4 are adsorbed through hydrogen bridges adjacent to hydroxyl groups. 2-Anions, achieving dual confinement of water and anions. By limiting the anions and destroying the ion pairs, the ionic conductivity of the ZnSO4+Al2O3 (IPA) colloidal electrolyte is improved. The hydroxyl groups on the surface of isopropyl alcohol / oxide have a coordination effect with H2O molecules. Isopropyl alcohol and nano-alumina can convert the intramolecular hydrogen bonds of H2O molecules into intermolecular hydrogen bonds and anchor water molecules on the surface of solid nanoparticles, thereby reducing water activity and inhibiting side reactions. (2) In the present invention, an electrolyte is obtained by adding a small amount of low-cost additives to a low-concentration salt solution, and it is applied in zinc ion energy storage batteries. The synthesis steps are simple and no special treatment is required. Compared with similar technologies, the zinc ion battery provided by the present invention has good cycle stability and reversibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 are the ionic conductivities of the ZnSO4+Al2O3 (IPA) electrolyte and the pure ZnSO4 electrolyte in Example 1 of the present invention, respectively;

[0019] Figure 2 are the wetting angles of the ZnSO4+Al2O3 (IPA) electrolyte and the pure ZnSO4 electrolyte on the zinc anode surface in Example 1 of the present invention, respectively;

[0020] Figure 3 To reflect the linear polarization curves of the zinc anode in the electrolyte of Example 1 of the present invention and the pure ZnSO4 electrolyte;

[0021] Figure 4 The electrochemical impedance spectroscopy curves of the symmetrical batteries assembled with the electrolyte in Example 1 and the electrolyte in Comparative Example 1;

[0022] Figure 5 The SEM images of the zinc electrode surface after 7 days of assembling the zinc electrode with the electrolyte in Example 1 and the electrolyte in Comparative Example 1 are shown. Figure 5 (a) Figure 5 (b) composition;

[0023] Figure 6 2D Raman mapping of the zinc electrode assembled with the electrolyte in Example 1 and the electrolyte in Comparative Example 1; Figure 6 (a) Figure 6 (b) composition;

[0024] Figure 7 The XRD patterns of the zinc electrodes soaked in the electrolytes of Example 1 and Comparative Example 1 are shown;

[0025] Figure 8 The symmetrical battery in Example 1 and the symmetrical battery in Comparative Example 1 were used at a current density of 1 mA cm -2 , areal capacity of 1 mAh cm -2Scanning electron microscope image after 50 cycles under the conditions; Figure 8 (a) Figure 8 (b) composition;

[0026] Figure 9 The symmetrical battery in Example 1 and the symmetrical battery in Comparative Example 1 were tested at a current density of 1 mA cm -2 , areal capacity of 1 mAh cm -2 The cycle performance diagram below;

[0027] Figure 10 The symmetrical battery in Example 1 and the symmetrical battery in Comparative Example 1 were tested at a current density of 5 mA cm -2 , areal capacity of 5 mAh cm -2 The cycle performance diagram below;

[0028] Figure 11 The full cell in Example 2 and the full cell in Comparative Example 2 at a current density of 1-6 mA cm -2 , areal capacity of 1 mAh cm -2 Lower rate cycle performance diagram;

[0029] Figure 12 The full cell in Example 2 and the full cell in Comparative Example 2 at a current density of 1 A g -1 Cycling performance at different current densities;

[0030] Figure 13 This is the constant current charge and discharge curve of the full battery in Example 2.

[0031] Figure 14 Constant current charge and discharge curve of the full battery in Comparative Example 2. DETAILED DESCRIPTION

[0032] The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific implementations disclosed below.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0034] Example 1

[0035] Preparation of nanocluster colloidal electrolyte:

[0036] 10 μl of nano-alumina (Al2O3(IPA)) dispersed in isopropyl alcohol (the average particle size of nano-alumina in the nano-alumina solution in isopropyl alcohol is 20 nm, and the solid content of nano-alumina in the nano-alumina solution in isopropyl alcohol is 20%) was uniformly mixed with 10 ml of ZnSO4 (2 M) electrolyte by ultrasonic treatment to obtain ZnSO4+Al2O3(IPA) colloidal electrolyte. An appropriate amount of electrolyte was dropped onto the zinc anode, and its wetting angle was as follows: Figure 2 The zinc anode was immersed in ZSO+Al2O3(IPA) colloidal electrolyte (i.e. ZnSO4+Al2O3 nanocluster colloidal electrolyte) for 7 days. The SEM image of the zinc anode surface is shown in Figure 2. Figure 5 As shown in (a), there is no obvious change on the surface of the zinc sheet immersed in the colloidal electrolyte. Figure 6 The 2D Raman mapping of (a) shows that the change in the byproduct count of the Zn flakes is significantly smaller than that of the Zn flakes in the blank ZnSO4 electrolyte, and Figure 7 The XRD test results also did not show any characteristic peaks of by-products, which indicates that the presence of Al2O3 (IPA) in the electrolyte helps to reduce the formation of by-products, potentially alleviating corrosion and improving the stability of the Zn anode during storage. The ionic conductivity of the resulting ZnSO4 + Al2O3 (IPA) colloidal electrolyte is 4.006Sm -1 The ionic conductivity of the electrolyte is as follows: Figure 1 shown.

[0037] Assembling symmetrical batteries

[0038] On an open-air test bench, two 16 mm diameter zinc electrodes were assembled into a CR2032 button cell. Whatman GF / D was used as the separator and the electrolyte was a ZSO+Al2O3 (IPA) colloidal electrolyte (ZnSO4+Al2O3 nanocluster colloidal electrolyte). The linear polarization curve of the assembled symmetrical cell is shown in Figure 2. Figure 3 As shown. The electrochemical impedance test was performed on it, and the results were as follows Figure 4 As shown. At a current density of 1 mA cm -2 , areal capacity of 1 mAh cm -2 Symmetrical battery cycle test was carried out under the test conditions, and the scanning electron microscope image after 50 cycles was as follows Figure 8 As shown in (a), the surface of the zinc sheet presents a flat stacking form, indicating a uniform deposition morphology. Figure 9 As shown in the figure, the polarization voltage does not exceed 0.1 V and gradually decreases to a stable state as the charge and discharge proceeds, and a stable cycle of more than 1000 h can be achieved. -2 , surface capacity of 5 mAhcm -2 Symmetrical battery cycle test results under the test conditions are as follows Figure 10 As shown in the figure, the symmetrical battery can still cycle stably for more than 1000h.

[0039] Example 2

[0040] Preparation of nanocluster colloidal electrolyte:

[0041] The process is the same as the preparation process of the electrolyte in Example 1.

[0042] Assembling a full battery

[0043] On an open-air test bench, a CR2032 full-cell was assembled with a zinc negative electrode sheet with a diameter of 16 mm and a V2O5 positive electrode with a diameter of 12 mm. A Whatman GF / D separator was used, and the electrolyte was a ZSO+Al2O3 (IPA) colloidal electrolyte (i.e., ZnSO4+Al2O3 nanocluster colloidal electrolyte). The full-cell was operated at a current density of 1-6 mA cm -2 , areal capacity of 1 mAh cm -2 The rate cycle performance test was carried out under the conditions, and the results were as follows Figure 11 As shown, it can be seen that at multiple current densities, the specific capacity of the Zn / / V2O5 full battery using nanocluster colloidal electrolyte is higher than that of the full battery not using ZSO+Al2O3 (IPA) colloidal electrolyte.

[0044] At 1 A g -1 Full battery cycle test was carried out under the test conditions, and the test results are as follows Figure 12 As shown, the initial discharge capacity is 213 mAh g -1 The capacity retention rate is higher than 80% when the cycle reaches 820 cycles. Figure 13 shown.

[0045] Example 3

[0046] Preparation of nanocluster colloidal electrolyte:

[0047] 30 μl of nanoalumina (Al2O3(IPA)) dispersed in isopropyl alcohol (the average particle size of the nanoalumina in the isopropyl alcohol nanoalumina solution is 20 nm, and the solid content of the nanoalumina in the isopropyl alcohol nanoalumina solution is 20%) was uniformly mixed with 10 ml of ZnSO4 (2 M) electrolyte by ultrasonic treatment to obtain a ZnSO4+Al2O3(IPA) colloidal electrolyte (i.e., a ZnSO4+Al2O3 nanocluster colloidal electrolyte). The ionic conductivity of the obtained ZnSO4+Al2O3(IPA) colloidal electrolyte was 3.721Sm -1 The ionic conductivity of the electrolyte is as follows: Figure 1 shown.

[0048] Example 4

[0049] Preparation of nanocluster colloidal electrolyte:

[0050] 10 μl of nanoalumina (Al2O3(IPA)) dispersed in isopropyl alcohol (the average particle size of the nanoalumina in the isopropyl alcohol nanoalumina solution is 20 nm, and the solid content of the nanoalumina in the isopropyl alcohol nanoalumina solution is 30%) was uniformly mixed with 10 ml of ZnSO4 (2 M) electrolyte by ultrasonic treatment to obtain a ZnSO4+Al2O3(IPA) colloidal electrolyte (i.e., a ZnSO4+Al2O3 nanocluster colloidal electrolyte). The ionic conductivity of the obtained ZnSO4+Al2O3(IPA) colloidal electrolyte was 3.813Sm -1 The ionic conductivity of the electrolyte is as follows: Figure 1 shown.

[0051] Comparative Example 1

[0052] Preparation of electrolyte:

[0053] ZnSO4 was dissolved in deionized water and mixed evenly by ultrasonic treatment to obtain an electrolyte solution with a molar concentration of about 2 M ZnSO4. The ionic conductivity of the electrolyte solution is as follows: Figure 1 As shown. A proper amount of electrolyte is dropped on the zinc anode, and its wetting angle is as follows Figure 2 The zinc anode was immersed in 2M ZnSO4 electrolyte for 7 days, and the SEM image of the zinc anode surface was shown as follows. Figure 5 (b) Figure 6 The 2D Raman mapping of (b) shows that the change in the zinc flake byproduct count is significantly greater than that in the ZSO+Al2O3(IPA) colloidal electrolyte obtained in Example 1, and Figure 7 The XRD test results showed that the characteristic peaks of by-products were generated. The ionic conductivity of the obtained electrolyte was 3.766Sm -1 The ionic conductivity of the electrolyte is as follows: Figure 1 shown.

[0054] Assembling symmetrical batteries

[0055] On an open-air test bench, two 16 mm diameter zinc electrodes were assembled into a CR2032 button cell, using Whatman GF / D as the separator and 2 M ZnSO4 as the electrolyte. The linear polarization curve of the assembled symmetrical cell is shown in Figure 2. Figure 3 As shown. The electrochemical impedance test was performed on it, and the results were as follows Figure 4 As shown. At a current density of 1 mA cm -2 , surface capacity is 1mAhcm -2Symmetrical battery cycle test was carried out under the test conditions, and the scanning electron microscope image after 50 cycles was as follows Figure 8 (b) The long-term cycle test results are shown in Figure 9 As shown, it can only be cycled stably for 160 h. -2 , surface capacity of 5mAh cm -2 Symmetrical battery cycle test results under the test conditions are as follows Figure 10 As shown in Figure 2, the symmetrical battery fails quickly after 100 h of fixed cycle.

[0056] Comparative Example 2

[0057] Assembling a full battery

[0058] The assembly process of the full cell is the same as that in Example 2, except that the electrolyte used is 2 M ZnSO4 electrolyte. The full cell is charged at a current density of 1-6 mA cm -2 , areal capacity of 1 mAh cm -2 The rate cycle performance test was carried out under the conditions, and the results were as follows Figure 11 As shown in the figure, it can be seen that at multiple current densities, the specific capacity of the Zn / / V2O5 full cell using 2 M ZnSO4 electrolyte is lower than that of the full cell using ZSO+Al2O3 (IPA) colloidal electrolyte. -1 Full battery cycle test was carried out under the test conditions, and the test results are as follows Figure 12 As shown, the initial discharge capacity is 203 mAh g -1 , the capacity retention rate is less than 80% when the cycle reaches 210 cycles. Figure 14 shown.

[0059] Comparative Example 3

[0060] Preparation of electrolyte:

[0061] ZnSO4 was dissolved in deionized water and uniformly mixed by ultrasonic treatment to obtain a ZnSO4 electrolyte solution with a molar concentration of approximately 2 M. An appropriate amount of nano-alumina particles with an average particle size of 20 nm was added to the electrolyte solution to obtain a mass fraction of 0.0157% (the amount of nano-alumina particles relative to the ZnSO4 electrolyte was exactly the same as in Example 1) to obtain a mixed electrolyte solution. The ionic conductivity of the mixed electrolyte solution was 3.651 Sm -1 The ionic conductivity of the electrolyte is as follows: Figure 1 As shown in the figure, since the ionic conductivity of the electrolyte is too low, it is not meaningful to conduct battery performance testing, so the subsequent battery assembly and battery performance testing experiments are omitted.

[0062] Comparative Example 4

[0063] Preparation of electrolyte:

[0064] 10 μl of nanoalumina (Al2O3(IPA)) dispersed in isopropyl alcohol (the average particle size of the nanoalumina in the isopropyl alcohol nanoalumina solution is 20 nm, and the solid content of the nanoalumina in the isopropyl alcohol nanoalumina solution is 50%) was uniformly mixed with 10 ml of ZnSO4 (2 M) electrolyte by ultrasonic treatment to obtain a ZnSO4+Al2O3(IPA) colloidal electrolyte with a molar concentration of approximately 13.1 mM / L. The ionic conductivity of the obtained ZnSO4+Al2O3(IPA) colloidal electrolyte was 3.558 Sm -1 The ionic conductivity of the electrolyte is as follows: Figure 1 As shown in the figure, since the ionic conductivity of the electrolyte is too low, it is not meaningful to conduct battery performance testing, so the subsequent battery assembly and battery performance testing experiments are omitted.

Claims

1. A nanocluster colloidal electrolyte, characterized in that: The nanocluster colloidal electrolyte comprises nano-aluminum oxide isopropyl alcohol dispersion and a zinc salt solution. The nano-aluminum oxide isopropyl alcohol dispersion comprises aluminum oxide nanoparticles and isopropyl alcohol. The zinc salt solution comprises solute zinc sulfate and solvent water.

2. The nanocluster colloidal electrolyte according to claim 1, characterized in that: The nano-cluster colloidal electrolyte is prepared by uniformly mixing nano-aluminum oxide dispersed in isopropyl alcohol and a zinc salt solution.

3. The nanocluster colloidal electrolyte according to claim 1, characterized in that: The colloidal solution is prepared by the following process: 5-30 μl, preferably 5-15 μl, more preferably 9-11 μl, is added to 8-15 ml, preferably 9-11 ml, of a zinc-containing solution; the mixture is stirred evenly to obtain a colloidal solution; the colloidal solution A is an isopropanol solution containing nano-alumina particles; the solid content of the nano-alumina particles in the isopropanol solution containing the nano-alumina particles is 2-30wt%, preferably 18-30wt%, more preferably 19-21wt%; and the zinc concentration in the zinc-containing solution is 0.2-2.5 mol / L, preferably 1.5-2.5 mol / L, more preferably 1.8-2.2 mol / L.

4. The nanocluster colloidal electrolyte according to claim 1, characterized in that: The wetting angle between the nanocluster colloidal electrolyte and the zinc anode is 77.5~78.5°.

5. The nanocluster colloidal electrolyte according to claim 1, characterized in that: The ionic conductivity of the nanocluster colloidal electrolyte is greater than 3.8Sm -1 After further optimization, the present invention is a nanocluster colloidal electrolyte, the ionic conductivity of the nanocluster colloidal electrolyte is 4.0~4.1Sm -1 .

6. The nanocluster colloidal electrolyte according to claim 1, characterized in that: The particle size of the nano-alumina particles is 10-500 nanometers, preferably 10-100 nanometers, and more preferably 15-25 nanometers.

7. The nanocluster colloidal electrolyte according to claim 3, characterized in that: According to the proportion, 10 μl of nano-alumina dispersed in isopropanol and 10 ml of 2 mol / L ZnSO4 solution were uniformly mixed by ultrasonic treatment to obtain a ZnSO4+Al2O3 nanocluster colloidal electrolyte; the average particle size of the nano-alumina in the isopropanol nano-alumina solution was 20 nm, and the solid content of the nano-alumina in the isopropanol nano-alumina solution was 20 wt%.

8. A use of the nanocluster colloidal electrolyte according to any one of claims 1 to 7, characterized in that: Including using it as an electrolyte for aqueous zinc-ion batteries.

9. The use of a nanocluster colloidal electrolyte according to claim 8, characterized in that: Two zinc electrodes were assembled into a CR2032 button cell, using Whatman GF / D as the separator and ZnSO4+Al2O3 nanocluster colloidal electrolyte as the electrolyte. The resulting symmetrical cell was tested at a current density of 5 mA cm -2 , areal capacity of 5 mAh cm -2 The test condition stability cycle time is greater than 1000 h.

10. The use of a nanocluster colloidal electrolyte according to claim 8, characterized in that: The zinc negative electrode and the V2O5 positive electrode were assembled into a CR2032 full battery, using Whatman GF / D as the separator and the electrolyte being ZnSO4+Al2O3 nanocluster colloidal electrolyte. The obtained full battery was -1 The full battery cycle test was carried out under the test conditions, and its initial discharge capacity was 213 mAh g -1 The capacity retention rate is higher than 80% when the cycle reaches 820 cycles.

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