Water-based zinc ion battery hydrogel electrolyte and water-based zinc ion battery

Abstract

Acrylamide (AM) is used as a polymer matrix, zinc perchlorate hexahydrate (Zn (ClO4) 2.6 H2O) and ethylene glycol (EG) eutectic solvent (DES) is introduced as a functional medium, and sodium carboxymethyl cellulose (CMC-Na) is compounded as a structure enhancer, so that the hydrogen bond density can be increased, and the water-based zinc ion battery hydrogel electrolyte can be used for preparing a water-based zinc ion battery. Meanwhile, the ionic conductivity and the zinc ion mobility are improved, a zinc ion rapid migration channel is constructed, zinc ions are induced to be uniformly deposited, and the water activity is reduced, so that a hydrogen evolution reaction, a corrosion side reaction and dendritic crystal growth are inhibited, and the rate capability and the cycle performance of the aqueous zinc ion battery are improved; the problems of low battery energy efficiency, short service life and the like caused by aggravated hydrogen evolution reaction, zinc metal corrosion and poor coordination capability of free Zn < 2 + > ions of the existing aqueous zinc ion battery are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aqueous zinc-ion batteries, and more specifically, relates to an aqueous gel electrolyte for an aqueous zinc-ion battery and an aqueous zinc-ion battery. Background Art

[0002] Aqueous zinc-ion batteries have broad prospects in the energy storage field due to the advantages of rich zinc resources, low cost, high safety, high specific capacity of zinc negative electrodes, and low electrochemical potential. In aqueous liquid electrolytes, when the battery is cycled, zinc dendrites grow on the anode surface, forming sharp dendrites, which are likely to pierce the separator, causing problems such as short circuits and sudden drops in capacity. While using solid electrolytes can avoid safety hazards such as leakage and short circuits, the conductivity of solid electrolytes is relatively low and the resistance is large, severely limiting the electrochemical performance.

[0003] Hydrogels are between solid and liquid phases, and have both the cohesive properties of solids. The flexible polymer network of the hydrogel can adapt to the volume change of the electrode material (such as the dissolution / deposition of the zinc negative electrode), reduce the interfacial stress, and enhance the mechanical stability. At the same time, the hydrogel contains a large amount of water, forming continuous ion transport channels, making its ionic conductivity close to that of liquid electrolytes, significantly higher than that of traditional solid electrolytes, and helping to improve the rate performance and charge-discharge efficiency of the battery. However, although the hydrogel electrolyte can avoid problems such as leakage, it does not deal with the growth of dendrites on the anode surface, which is likely to cause the dissolution and structural collapse of the positive electrode material, resulting in the attenuation of the battery capacity. At the same time, the zinc electrode will also undergo corrosion and hydrogen evolution reaction (HER), reducing the Coulombic efficiency (CE), affecting the cycle stability, and hindering practical applications.

[0004] In CN115377487A, a ternary cross-linked gel electrolyte for zinc-ion batteries and its preparation and application disclose that acrylamide, a polysaccharide derivative rich in hydroxyl groups, and a polyanionic natural polymer containing carboxylate groups are used to initiate a free radical polymerization reaction to obtain a ternary cross-linked hydrogel electrolyte. The polysaccharide derivative rich in hydroxyl groups is introduced into this electrolyte. The hydroxyl groups in its cross-linked network structure can effectively convert free water into bound water as hydrophilic groups, reducing the activity of water in the system and decreasing the occurrence of side reactions caused by free water attacking the cathode material, thereby alleviating the problem of dissolution and collapse of the cathode material structure. In addition, a polyanionic natural polymer containing carboxylate groups is introduced. The sodium carboxylate groups in its cross-linked network structure produce ionic cross-linking with zinc ions, guiding the uniform deposition of zinc through ion confinement, reducing the formation of zinc dendrites on the negative electrode surface, and effectively improving the limitations of the positive and negative electrodes of aqueous zinc-ion batteries in traditional liquid electrolytes. Additionally, polyacrylamide is used as the polymer backbone, and a polysaccharide derivative and a polyanionic natural polymer containing carboxylate groups are used as the hierarchical structure of the multiple cross-linked network to synthesize a hydrogel with a dynamic covalent cross-linked structure, endowing it with the advantages of high ionic conductivity and good mechanical properties. Although this patent can reduce the formation of zinc dendrites on the negative electrode surface, it cannot effectively regulate the strong hydrogen bond network structure formed by the interaction of water molecules in the electrolyte, and fails to further weaken the bound water in the strong hydrogen bond network, resulting in the aggravation of the hydrogen evolution reaction and zinc metal corrosion problems, significantly reducing the battery energy efficiency and shortening the cycle life. Additionally, the dissociation mechanism has a weak ability to provide a supplementary zinc source and also lacks the coordination ability with free Zn 2+ ions, making it difficult to overcome the hindrance of the PAM polymer network to cation migration and resulting in sluggish zinc-ion transport kinetics. Summary of the Invention

[0005] The present invention aims to overcome the problems existing in the hydrogel electrolyte of existing aqueous zinc-ion batteries, such as the aggravation of the hydrogen evolution reaction, zinc metal corrosion, poor coordination ability of free Zn 2+ ions leading to low battery energy efficiency and short lifespan, and provides a hydrogel electrolyte for aqueous zinc-ion batteries.

[0006] Another technical problem solved by the present invention is to provide an aqueous zinc-ion battery based on the hydrogel electrolyte for aqueous zinc-ion batteries.

[0007] The present invention is achieved through the following technical solutions:

[0008] A hydrogel electrolyte for an aqueous zinc-ion battery, the raw materials including 15-17 wt.% of acrylamide, 28-30 wt.% of zinc salt, 5-7 wt.% of DES solvent, 0.3-0.5 wt.% of sodium carboxymethylcellulose, 0.009-0.011 wt.% of crosslinking agent, 0.05-0.07 wt.% of initiator, and the balance being water, wherein the DES solvent includes zinc perchlorate hexahydrate and ethylene glycol.

[0009] Further, the zinc salt includes one or more of zinc sulfate heptahydrate, zinc acetate, and zinc nitrate.

[0010] Further, the concentration of zinc perchlorate hexahydrate in the DES solvent is 0.3-0.4 mol / L.

[0011] Further, the crosslinking agent is one or more of N,N'-methylenebisacrylamide, bis(acryloyl)cystamine, and pentaerythritol tetraacrylate.

[0012] Further, the initiator is a persulfate, including one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

[0013] Further, the raw materials include acrylamide, zinc sulfate heptahydrate, DES solvent, sodium carboxymethylcellulose, N,N'-methylenebisacrylamide, ammonium sulfate, and water.

[0014] Further, the preparation steps of the hydrogel electrolyte for the aqueous zinc-ion battery include:

[0015] Dissolve the zinc salt in deionized water, then add the DES solvent, sodium carboxymethylcellulose, crosslinking agent, and initiator, stir evenly, and react to obtain the hydrogel electrolyte for the aqueous zinc-ion battery.

[0016] Further, the stirring speed is 500-1300 r / min, and the stirring time is 10-15 min.

[0017] Further, the reaction temperature is 55-65 °C, and the reaction time is 0.5-1 h.

[0018] An aqueous zinc-ion battery includes the above-mentioned hydrogel electrolyte for the aqueous zinc-ion battery.

[0019] Further, the hydrogel electrolyte for the aqueous zinc-ion battery includes a positive electrode, a negative electrode, and a hydrogel electrolyte, the positive electrode is vanadium pentoxide, vanadium dioxide, or manganese dioxide, the negative electrode is a zinc sheet, and the electrolyte is the hydrogel electrolyte for the aqueous zinc-ion battery.

[0020] Further, the aqueous zinc-ion battery is one of an aqueous zinc-ion symmetric battery, an aqueous zinc-ion zinc-copper battery, an aqueous zinc-ion zinc-stainless steel mesh battery, and an aqueous zinc-ion full battery.

[0021] Compared with the prior art, the beneficial effects are as follows:

[0022] In the present invention, acrylamide (AM) is used as the polymer matrix, and a novel deep eutectic solvent (DES) prepared from zinc perchlorate hexahydrate (Zn(ClO4)2·6H2O) and ethylene glycol (EG) is introduced as the functional medium, and sodium carboxymethyl cellulose (CMC-Na) is compounded as the structural enhancer. Among them, ClO4 in the DES - enters the solvation sheath of Zn 2+ , replacing some strongly coordinating water molecules ([Zn(H2O)6] 2+ ), accelerating the migration of Zn 2+ ; the hydroxyl group (-OH) of EG competes with water molecules to form hydrogen bonds, reducing the proportion of free water and inhibiting the hydrogen evolution reaction (HER) and zinc corrosion; the coordination of -COO- with Zn 2+ reduces the concentration of free Zn 2+ , inhibits the formation of by-products such as zinc basic sulfate (Zn4SO4(OH)6·xH2O), prolongs the cycle life, and at the same time provides a fast migration channel for Zn 2+ , facilitating the rapid migration of zinc ions; the hydroxyl group (-OH) and carboxylate group (-COO-) of CMC-Na form multiple hydrogen bonds and ionic coordination bonds with H2O, EG, and Zn 2+ , constructing a dynamic cross-linked network, weakening the strong hydrogen bonds formed by water and further anchoring water molecules in the polymer network. The three-dimensional network structure of sodium carboxymethyl cellulose provides better support, combined with the viscoelasticity of DES, improving the flexibility of the hydrogel, while restricting the movement of water molecules, reducing the activity of water, guiding the uniform deposition of zinc ions, slowing down the hydrogen evolution corrosion reaction, and reducing the generation of zinc dendrites, which can improve the ionic conductivity and zinc ion mobility, optimize the coordination effect of Zn 2+ , thereby improving the performance of aqueous zinc-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the stress-strain curve diagram of the hydrogel electrolyte using Example 1 and Comparative Example 1;

[0024] Figure 2 It is the hydrogel ionic conductivity diagram of the platinum symmetric battery using Example 1 and Comparative Example 1;

[0025] Figure 3 It is the impedance diagram and zinc ion mobility diagram using Example 1 and Comparative Examples 1-2;

[0027] Figure 4 It is the Tafel curve diagram of the zinc symmetric battery using Example 1 and Comparative Examples 1-2;

[0028] Figure 5 For the overpotential nucleation diagrams of the zinc-copper half-cells in Example 1 and Comparative Examples 1-2 at a current density of 1 mA cm -2 , 1 mAh cm -2 ;

[0029] Figure 6 For the rate performance comparison diagrams of the zinc symmetric cells in Example 1 and Comparative Examples 1-2 at different current densities with an areal capacity of 1 mAh cm -2 ; where Figure 6 a is the rate performance comparison diagram from 0 to 90 h, and the rate performance from 0 to 30 h is taken as Figure 6 b;

[0030] Figure 7 For the rate performance diagrams of the full cells using Example 1 and Comparative Examples 1-2 at current densities of 0.1 A g -1 , 0.2 A g -1 , 0.3 A g -1 , 0.5 A g -1 , 1 A g -1 ;

[0031] Figure 8 For the long cycle diagram of the full cells using Example 1 and Comparative Examples 1-2 at a current density of 1 A g -1 . Detailed implementation manners

[0032] The following further explains and clarifies with reference to the examples, but the specific examples do not limit the present invention in any form. Unless otherwise specified, the methods and equipment used in the examples are conventional methods and equipment in the art, and the raw materials used are all conventional commercially available raw materials.

[0033] All the raw materials used are conventional commercially available raw materials.

[0034] Example 1

[0035] A hydrogel electrolyte for an aqueous zinc-ion battery, comprising 16.18 wt.% of acrylamide (AM), 0.0098 wt.% of N,N'-methylenebisacrylamide (MBA), 28.20 wt.% of zinc sulfate heptahydrate (ZnSO4·7H2O), 0.065 wt.% of ammonium persulfate, 6.08 wt.% of DES solvent, 0.49 wt.% of sodium carboxymethylcellulose (CMC-Na), and the balance being deionized water (H2O);

[0036] The preparation method of the above-mentioned hydrogel electrolyte for an aqueous zinc-ion battery, the specific steps are as follows:

[0037] S1. Dissolve 50 mg of MBA in 5 mL of deionized water, and stir it magnetically at room temperature until MBA is completely dissolved to obtain a 10 mg / mL MBA solution.

[0038] S2. Disperse 1.24 g of zinc perchlorate hexahydrate in 10 mL of EG, and stir it magnetically at room temperature until zinc perchlorate hexahydrate is completely dissolved to obtain a DES solution.

[0039] S3. Disperse 3.3 g of AM in 10 mL of deionized water, add 5.75 g of zinc sulfate heptahydrate, pipette 200 μL of the MBA solution in (1), then stir it magnetically at room temperature until zinc sulfate and AM are completely dissolved. Then pipette 1 mL of the DES solution, add 0.1 g of CMC-Na, stir until CMC-Na is dissolved, and finally add 13.3 mg of ammonium persulfate. After stirring magnetically until ammonium persulfate is dissolved, pour it into a mold, seal it, and place it in an oven at 60 °C for 0.5 h and then take it out.

[0040] S4. Demold the mold, seal the hydrogel electrolyte with plastic wrap and let it stand for 2 h to eliminate internal stress, obtaining the hydrogel electrolyte.

[0041] Example 2

[0042] A hydrogel electrolyte for aqueous zinc-ion batteries, comprising 15 wt.% of acrylamide (AM), 0.009 wt.% of N,N'-methylenebisacrylamide (MBA), 28 wt.% of zinc sulfate heptahydrate (ZnSO4·7H2O), 0.05 wt.% of ammonium persulfate, 5 wt.% of DES solvent, 0.3 wt.% of sodium carboxymethylcellulose (CMC-Na), and the rest is deionized water (H2O). Its preparation process is the same as that of Example 1.

[0043] Example 3

[0044] A hydrogel electrolyte for aqueous zinc-ion batteries, comprising 17 wt.% of acrylamide (AM), 0.011 wt.% of N,N'-methylenebisacrylamide (MBA), 30 wt.% of zinc sulfate heptahydrate (ZnSO4·7H2O), 0.07 wt.% of ammonium persulfate, 7 wt.% of DES solvent, 0.5 wt.% of sodium carboxymethylcellulose (CMC-Na), and the rest is deionized water (H2O). Its preparation process is the same as that of Example 1.

[0045] In the above examples, zinc sulfate heptahydrate can also be one or more of zinc acetate and zinc nitrate, the cross-linking agent N,N'-methylenebisacrylamide can also be one or more of bis(acryloyl)cystamine and pentaerythritol tetraacrylate, and the initiator ammonium persulfate can also be one or more of sodium persulfate and potassium persulfate.

[0046] Comparative Example 1

[0047] A hydrogel electrolyte for an aqueous zinc-ion battery, comprising acrylamide (AM), N,N'-methylenebisacrylamide (MBA), deionized water (H2O), zinc sulfate heptahydrate (ZnSO4·7H2O), and persulfate.

[0048] The preparation method of the above-mentioned hydrogel electrolyte for an aqueous zinc-ion battery, the specific steps are as follows:

[0049] S1. Take 50 mg of MBA and disperse it in 5 mL of deionized water, and magnetically stir it at room temperature until the MBA is completely dissolved to obtain a 10 mg / mL MBA solution.

[0050] S2. Take 3.3 g of AM and disperse it in 10 mL of deionized water, add 5.75 g of zinc sulfate heptahydrate, pipette 200 μL of the MBA solution in (1) with a pipette gun, and then magnetically stir it at room temperature until the zinc sulfate and AM are completely dissolved. Finally, add 13.3 mg of ammonium persulfate, and magnetically stir until the ammonium persulfate is dissolved, then pour it into a square mold, seal it with plastic wrap, and place it in an oven at 60 °C for 0.5 h and then take it out;

[0051] S3. Demold the square mold, seal the hydrogel electrolyte with plastic wrap and let it stand for 2 h to eliminate internal stress, and obtain the hydrogel electrolyte.

[0052] The persulfate in the above examples and comparative examples can also be selected from one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

[0053] Comparative Example 2

[0054] An electrolyte for an aqueous zinc-ion battery, comprising zinc sulfate heptahydrate and deionized water.

[0055] The preparation method of the above-mentioned electrolyte for an aqueous zinc-ion battery, the specific steps are as follows: Take 5.75 g of zinc sulfate heptahydrate and disperse it in 10 mL of deionized water, and then magnetically stir it at room temperature until the zinc sulfate is completely dissolved to obtain a ZnSO4 electrolyte.

[0056] Assemble batteries with the electrolytes obtained in Example 1, Comparative Example 1, and Comparative Example 2, respectively:

[0057] Example 1, Comparative Example 1:

[0058] Aqueous zinc-ion symmetric battery: Assemble a zinc symmetric battery in the order of negative electrode shell - negative electrode zinc sheet - hydrogel electrolyte - positive electrode zinc sheet - gasket - positive electrode shell.

[0059] Aqueous zinc-ion symmetric battery: Assemble a platinum symmetric battery in the order of copper sheet wire - platinum sheet - hydrogel electrolyte - platinum sheet - gasket.

[0060] Aqueous zinc-ion zinc-copper battery: Assemble a half-cell in the order of negative electrode shell - negative zinc sheet - hydrogel electrolyte - positive copper sheet - gasket - positive electrode shell.

[0061] Aqueous zinc-ion full battery: Assemble a full battery in the order of negative electrode shell - negative zinc sheet - hydrogel electrolyte - stainless steel mesh loaded with VO2 at the positive electrode - gasket - positive electrode shell.

[0062] Comparative Example 2:

[0063] Aqueous zinc-ion symmetric battery: Drop 180 μL of the electrolyte prepared in Comparative Example 2 on glass fiber, and assemble a zinc symmetric battery in the order of negative electrode shell - negative zinc sheet - separator - electrolyte - positive zinc sheet - gasket - positive electrode shell.

[0064] Aqueous zinc-ion zinc-copper battery: Drop 180 μL of the electrolyte prepared in Comparative Example 2 on glass fiber, and assemble a half-cell in the order of negative electrode shell - negative zinc sheet - separator - electrolyte - positive copper sheet - gasket - positive electrode shell.

[0065] Aqueous zinc-ion full battery: Drop 180 μL of the electrolyte prepared in Comparative Example 2 on glass fiber, and assemble a full battery in the order of negative electrode shell - negative zinc sheet - separator - electrolyte - stainless steel mesh loaded with VO2 at the positive electrode - gasket - positive electrode shell.

[0066] Detect the mechanical properties and electrical properties of the electrolytes in Example 1, Comparative Example 1, and Comparative Example 2 above. The test results are as follows:

[0067] As Figure 1 shown, the maximum stress in Example 1 is 90 Kpa, and the strain is 1300%. As a structural enhancer, CMC-Na forms strong hydrogen bonds (O-H…O) with water molecules (H2O) through the hydroxyl groups (-OH) of EG, destroys the hydrogen bond network of water itself (H2O…H2O), reduces the proportion of free water, weakens the activity of water. At the same time, the hydroxyl groups (-OH) and carboxylate groups (-COO - ) of CMC-Na form multi-level hydrogen bonds with H2O and EG, greatly improving the strain without significantly reducing the stress, making the hydrogel electrolyte have more excellent mechanical properties.

[0068] As Figure 2 shown, the ionic conductivity in Example 1 is 29.26 mS cm -1 , while the ionic conductivity in Comparative Example 1 is only 22.17 mS cm -1, indicating that CMC-Na constructs a fast channel for ion migration, more effectively transports zinc ions, and improves the charge and discharge speed of the battery.

[0069] It can be seen from Figure 3 that the zinc ion mobility in Example 1 is as high as 0.63, while the zinc ion mobilities in Comparative Examples 1-2 are 0.14 and 0.31 respectively, indicating that the carboxylate groups of CMC-Na electrostatically adsorb Zn 2+ , and cooperate with ClO4 in DES - to jointly guide the migration of zinc ions and construct a fast migration channel for zinc ions.

[0070] It can be seen from Figure 4 that the corrosion current of Application Example 1 is 0.0310 mA / cm² -2 , while the corrosion currents of Comparative Application Examples 1-2 are 0.0466 mA / cm² -2 and 0.0868 mA / cm² -2 respectively, indicating that Application Example 1 reduces the corrosion side reactions occurring at the zinc negative electrode / electrolyte (hydrogel electrolyte) interface, helps reduce the corrosion and loss of the zinc negative electrode, and thus prolongs the cycle life of the battery.

[0071] It can be seen from Figure 5 that the nucleation overpotential of Application Example 1 is 95 mV, while the nucleation overpotentials of Comparative Application Examples 1-2 are 56 mV and 81 mV respectively, indicating that the deposition driving force of zinc ions in the electrolyte in Application Example 1 is enhanced, which helps to form a more uniform and dense zinc deposition layer and reduce the polarization phenomenon during the charge and discharge process of the battery.

[0072] It can be seen from Figure 6 a that for the symmetric batteries of Application Example 1 and Comparative Application Example 1, zinc ion deposition and stripping can be ensured at a current density of 1-5 mA / cm² -2 , 1 mAh / cm² -2 , but the polarization voltage of Application Example 1 is less than that of Comparative Application Example 1, meaning that the internal resistance and polarization phenomenon in the battery are smaller, which helps to reduce the internal loss during the charge and discharge process of the battery, improve the energy efficiency of the battery, and prolong the battery life. However, for the symmetric battery of Comparative Application Example 2, soft short circuit occurs when the current density changes from 2 mA / cm² -2 , 1 mAh / cm² -2 ( Figure 6 b).

[0073] It can be seen from Figure 7 that the rate capacity of the full battery in Example 1 is higher than that of the full batteries in Comparative Examples 1-2.

[0074] It can be seen from Figure 8It can be seen that the full-cell long-cycle capacity in Example 1 is higher than that in Comparative Examples 1-2. In the DES of the present invention, EG binds free water through hydrogen bonds, reduces the water activity, and reduces the dissolution loss of the VO2 active material, showing more excellent performance in the full-cell cycle.

[0075] The present invention uses acrylamide (AM) as a polymer matrix, introduces a new type of deep eutectic solvent (DES) prepared from zinc perchlorate hexahydrate (Zn(ClO4)2·6H2O) and ethylene glycol (EG) as a functional medium, and composites sodium carboxymethyl cellulose (CMC-Na) as a structural enhancer. The prepared hydrogel electrolyte improves its stress-strain value in terms of mechanical properties, increases the flexibility of the hydrogel electrolyte. At the same time, the weakly coordinating ClO4 - anion promotes Zn 2+ efficient dissociation. Ethylene glycol (EG) acts as a hydrogen bond donor, reducing the size of hydration, thereby reducing the migration resistance. At the same time, CMC-Na releases free Na+, effectively increasing the carrier concentration in the dynamic network. The impedance starting point of the present invention is only 4.34 Ω, with a high ionic conductivity of 29.26 mS cm -1 and a high zinc ion mobility of 0.63, which is superior to pure PAM electrolyte and zinc sulfate electrolyte. Therefore, the present invention uses DES as a functional medium and CMC-Na as a structural enhancer, significantly improving the charge-discharge efficiency and performance of the battery, extending the service life, and reducing polarization and heat accumulation, thereby improving the safety and overall reliability of the battery, bringing significant advantages to energy storage applications and promoting the development of the next generation of high-performance FZIBS.

[0076] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A hydrogel electrolyte for an aqueous zinc-ion battery, characterized in that, The raw materials include 15 - 17 wt.% of acrylamide, 28 - 30 wt.% of zinc salt, 5 - 7% of DES solvent, 0.3 - 0.5 wt.% of sodium carboxymethyl cellulose, 0.009 - 0.011 wt.% of crosslinking agent, 0.05 - 0.07 wt.% of initiator, and the balance is water. The DES solvent includes zinc perchlorate hexahydrate and ethylene glycol.

2. The hydrogel electrolyte for the aqueous zinc ion battery according to claim 1, characterized in that, The zinc salt includes one or more of zinc sulfate heptahydrate, zinc acetate, and zinc nitrate.

3. The hydrogel electrolyte for an aqueous zinc ion battery according to claim 1, wherein The concentration of zinc perchlorate hexahydrate in the DES solvent is 0.3 - 0.4 mol / L.

4. The hydrogel electrolyte for an aqueous zinc ion battery according to claim 1, wherein The crosslinking agent is one or more of N,N'-methylenebisacrylamide, bis(acryloyl)cystamine, and pentaerythritol tetraacrylate.

5. The hydrogel electrolyte for an aqueous zinc ion battery according to claim 1, wherein The initiator includes one or more of ammonium persulfate, sodium persulfate, and potassium persulfate.

6. The hydrogel electrolyte for the aqueous zinc ion battery according to claim 1, wherein The raw materials include acrylamide, zinc sulfate heptahydrate, DES solvent, sodium carboxymethyl cellulose, N,N'-methylenebisacrylamide, ammonium sulfate, and water. The DES solvent includes zinc perchlorate hexahydrate and ethylene glycol.

7. The hydrogel electrolyte for an aqueous zinc-ion battery according to claim 1, wherein The preparation steps include: Dissolve the zinc salt in deionized water, then add the DES solvent, sodium carboxymethyl cellulose, crosslinking agent, and initiator, stir evenly, and react to obtain the hydrogel electrolyte for aqueous zinc-ion battery.

8. The hydrogel electrolyte for the aqueous zinc ion battery according to claim 1, wherein The reaction temperature is 55 - 65 °C, and the reaction time is 0.5 - 1 h.

9. An aqueous zinc-ion battery, characterized in that, It includes the hydrogel electrolyte for aqueous zinc-ion battery according to any one of claims 1 - 8.

10. The aqueous zinc-ion battery according to claim 9, characterized in that, It includes a positive electrode, a negative electrode, and a hydrogel electrolyte. The positive electrode is vanadium pentoxide, vanadium dioxide, or manganese dioxide. The negative electrode is a zinc sheet, and the electrolyte is the hydrogel electrolyte for aqueous zinc-ion battery.

Images