A ternary crosslinked gel electrolyte for zinc-ion batteries, its preparation and application

Abstract

This invention discloses a ternary crosslinked gel electrolyte for zinc-ion batteries, its preparation, and its application. A ternary crosslinked hydrogel is obtained by crosslinking and polymerizing three polymer raw materials—polyacrylamide, a hydroxyl-rich polysaccharide derivative, and a carboxylate-containing polyanionic natural polymer—under thermal initiation conditions. The ternary crosslinked gel electrolyte prepared by this invention has a hierarchical structure with a three-layer crosslinked polymer network, providing excellent compression and resilience performance. Furthermore, the electrostatic attraction between the electrolyte and ions guides uniform zinc deposition, enabling it to maintain electrochemical performance under long-term charge-discharge cycles in ion batteries. It offers advantages such as high safety and low cost, and has significant application prospects in batteries.

Description

Technical Field

[0001] This invention belongs to the field of chemical power sources, specifically relating to a ternary cross-linked gel electrolyte for zinc-ion batteries, its preparation, and its application. Background Technology

[0002] Rechargeable aqueous zinc-ion batteries are gaining increasing attention due to their advantages such as being non-toxic, relatively safe, and low-cost. However, in aqueous liquid electrolytes, the charging / discharging process of zinc-ion batteries is affected by the presence of Zn... 2+ During electroplating / stripping, zinc dendrites inevitably grow on the zinc anode surface. If these sharp zinc dendrites are not effectively suppressed, they will eventually penetrate the electrolyte separator, leading to battery short circuits and malfunctions. To suppress zinc dendrite growth, researchers have reported a series of solutions, such as introducing electrolyte additives, modifying the zinc anode surface with coatings, zinc-induced deposition, and physical isolation. Furthermore, the aqueous liquid electrolytes commonly used in existing technologies contain a large amount of free water, which can trigger side reactions that cause the dissolution and structural collapse of the cathode material, resulting in rapid capacity decay of the battery.

[0003] Electrolytes, as a key component of energy storage devices, are one of the main factors affecting the electrochemical performance of these devices. Currently used electrolytes are mainly divided into two categories: liquid electrolytes and solid electrolytes. Liquid electrolytes have disadvantages such as high fluidity and difficulty in encapsulation, and pose risks such as leakage, gas expansion, and explosion, seriously affecting the safety of device use.

[0004] Solid electrolytes can effectively solve safety hazards such as leakage and explosion, but solid electrolytes have relatively low conductivity and high electrode-electrolyte interface resistance, which seriously limits the electrochemical performance of energy storage devices.

[0005] In response to the limitations of aqueous zinc-ion batteries in liquid electrolytes, researchers initially shifted their strategy to developing and applying solid electrolytes, attempting to alleviate the problem of cathode material dissolution and collapse by reducing the proportion of free water. However, due to the excessively high mechanical hardness of solid electrolytes, they cannot achieve a good adhesion and wetting state with the electrode interface, so their high interfacial impedance affects the overall capacity of the battery.

[0006] Based on the above advantages and disadvantages, quasi-solid hydrogel electrolytes, which lie between solid and liquid phases, have emerged. Hydrogels combine the transport and diffusion capabilities of liquids with the cohesive properties of solids, effectively integrating the advantages of both. Gel polymer electrolytes, often referred to as semi-solid electrolytes in many reports, avoid the leakage problems of liquid electrolytes while maintaining high ionic conductivity. However, traditional gel electrolytes lack a hierarchical structure, resulting in a negative correlation between their mechanical properties and ionic conductivity, which fails to meet the requirements of wearable devices and flexible energy storage devices.

[0007] Most reported gel electrolytes only consider the effect of a single factor on dendrite growth, and their treatment effect is not obvious.

[0008] Therefore, developing a novel hydrogel electrolyte with a hierarchical structure featuring a multi-layer cross-linked network, high conductivity, good mechanical properties, and the ability to incorporate various strategies for suppressing zinc dendrite formation is crucial for the development of zinc-ion batteries. Summary of the Invention

[0009] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0010] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0011] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a ternary crosslinked hydrogel electrolyte.

[0012] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a ternary crosslinked hydrogel electrolyte, comprising,

[0013] Preparation of precursor: Acrylamide, hydroxyl-rich polysaccharide derivatives and carboxylate-containing polyanionic natural polymers are added sequentially to deionized water and stirred. The mixture is then ultrasonically dispersed to remove air bubbles. Finally, a crosslinking agent and an initiator are added and stirred to obtain a homogeneous precursor.

[0014] Preparation of ternary cross-linked hydrogel electrolyte: After the precursor is poured into a mold, it is heated to initiate a free radical polymerization reaction. After the cross-linking polymerization is completed, it is immersed in a salt solution to reach swelling equilibrium, thus obtaining the ternary cross-linked hydrogel electrolyte.

[0015] As a preferred embodiment of the preparation method of the ternary crosslinked hydrogel electrolyte of the present invention, the polysaccharide derivative rich in hydroxyl groups includes one or more of soluble starch, locust bean gum, konjac gum, chitosan, xanthan gum, and carrageenan.

[0016] The carboxylate-containing polyanionic natural polymer includes one or more of sodium alginate, sodium carboxymethyl cellulose, gelatin, citric acid, and sodium carboxymethyl starch.

[0017] The crosslinking agent includes one or more of N,N-methylenebisacrylamide, polyethylene glycol diacrylate, and dicumyl peroxide;

[0018] The initiator includes one or more of potassium persulfate and ammonium persulfate;

[0019] The salt solution is a mixed solution of 0.1–5 mol / L zinc sulfate and 0.01–2 mol / L manganese sulfate.

[0020] In a preferred embodiment of the preparation method of the ternary crosslinked hydrogel electrolyte of the present invention, the mass ratio of the acrylamide, the hydroxyl-rich polysaccharide derivative and the carboxylate-containing polyanionic natural polymer ternary combination is 1:0.01-0.5:0.01-0.5.

[0021] In a preferred embodiment of the preparation method of the ternary crosslinked hydrogel electrolyte of the present invention, the acrylamide in the hydrogel system is 0.2-20% by mass; the polysaccharide derivative in the hydrogel system is 0.01-10% by mass; and the carboxylate-containing polyanionic natural polymer in the hydrogel system is 0.01-10% by mass.

[0022] In a preferred embodiment of the preparation method of the ternary crosslinked hydrogel electrolyte of the present invention, the crosslinking agent has a mass percentage of 0.001 to 10% in the hydrogel system, and the initiator has a mass percentage of 0.001 to 10% in the hydrogel system.

[0023] In a preferred embodiment of the preparation method of the ternary crosslinked hydrogel electrolyte of the present invention, the preparation of the precursor includes a magnetic stirring time of 0.1 to 120 h and an ultrasonic dispersion time of 0.1 to 5 h.

[0024] As a preferred embodiment of the preparation method of the ternary cross-linked hydrogel electrolyte of the present invention, the preparation of the ternary cross-linked hydrogel electrolyte includes a heating temperature of 50-100°C, a heating time of 0.1-72 h, and a swelling time of 0.2-96 h.

[0025] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a ternary crosslinked hydrogel electrolyte.

[0026] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a ternary cross-linked hydrogel electrolyte for the application of the product in battery manufacturing, including assembling a zinc-ion battery with a positive electrode-electrolyte-negative electrode "sandwich" structure and a ternary cross-linked hydrogel system as the electrolyte.

[0027] In a preferred embodiment of the application described in this invention, the negative electrode comprises metallic zinc, and the positive electrode material comprises one or more of manganese-based materials, vanadium-based materials, and cobalt-based materials.

[0028] Beneficial effects of this invention:

[0029] (1) The ternary cross-linked hydrogel electrolyte disclosed in this invention can maintain stable electrochemical performance under long-term charge-discharge cycles in zinc-ion batteries. Since the hydrogel in this invention introduces polysaccharide derivatives rich in hydroxyl groups, the hydroxyl groups in its cross-linked network structure can effectively convert free water into bound water as hydrophilic groups, thereby reducing the activity of water in the system and reducing the occurrence of side reactions caused by free water attacking the cathode material, thus alleviating the problem of dissolution and collapse of the cathode material structure. In addition, the hydrogel in this invention introduces polyanionic natural polymers containing carboxylate groups. The sodium carboxylate groups in its cross-linked network structure generate ionic cross-links with zinc ions, guiding the uniform deposition of zinc through ion confinement and reducing the formation of zinc dendrites on the negative electrode surface. Thus, the gel electrolyte in this invention effectively improves the limitations of the positive and negative electrodes of aqueous zinc-ion batteries in traditional liquid electrolytes.

[0030] (2) The ternary cross-linked hydrogel electrolyte disclosed in this invention uses polyacrylamide as a polymer backbone and contains polysaccharide derivatives and carboxylate-containing polyanionic natural polymers as a hierarchical structure of multiple cross-linked networks to synthesize a hydrogel with a dynamic covalent cross-linked structure, which has the advantages of high ionic conductivity and good mechanical properties. Among them, the polysaccharide derivatives rich in hydroxyl groups can form a large number of hydrogen bonds with amide groups, giving the system excellent mechanical resilience, making it difficult for zinc dendrites to puncture the electrolyte membrane and cause short circuits. Therefore, the gel electrolyte in this invention combines multiple strategies to inhibit zinc dendrites, such as zinc-induced deposition and physical isolation, which effectively improves the problem of zinc dendrite growth on the negative electrode of zinc-ion batteries and achieves better uniform zinc deposition.

[0031] (3) The entire synthesis process of this invention is simple and easy to operate, with 100% utilization of raw materials, and is environmentally friendly and safe. It is an environmentally friendly invention. The raw materials are commonly used natural polymers that are non-toxic. The main component of the system is water, which has little irritation to the human body and therefore has good biological safety. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0033] Figure 1 The image shows the microstructure of the hydrogel electrolyte prepared in Example 1 under a scanning electron microscope.

[0034] Figure 2The stress-strain curve of the hydrogel electrolyte prepared in Example 1 under 99% compressive deformation;

[0035] Figure 3 This is a comparison graph showing the charge-discharge cycle of the hydrogel electrolyte prepared in Example 1 at a current density of 1 A / g in a zinc-ion battery with that of the liquid electrolyte under the same conditions.

[0036] Figure 4 The XRD pattern of the zinc sheet surface of the hydrogel electrolyte prepared in Example 1 after 300 charge-discharge cycles in a zinc-ion battery is compared with that of the liquid electrolyte under the same conditions.

[0037] Figure 5 The ionic conductivity of the hydrogel electrolyte prepared in Example 1 was measured by AC impedance spectroscopy.

[0038] Figure 6 The CV curve of the hydrogel electrolyte prepared in Example 1 is obtained by cyclic voltammetry in a zinc-ion battery. Detailed Implementation

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0040] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0041] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0042] The chemical reagents used in this invention are shown in Table 1.

[0043] Table 1

[0044]

[0045] Example 1

[0046] 1g acrylamide, 0.1g soluble starch and 0.1g sodium carboxymethyl cellulose were added sequentially to 10ml deionized water and magnetically stirred for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g N,N-methylenebisacrylamide and 0.01g potassium persulfate were added and the mixture was stirred to obtain a homogeneous precursor.

[0047] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining a ternary crosslinked hydrogel electrolyte of polyacrylamide-soluble starch-sodium carboxymethyl cellulose.

[0048] Example 2

[0049] 1g acrylamide, 0.1g konjac gum and 0.1g sodium carboxymethyl cellulose were added sequentially to 10ml deionized water and magnetically stirred for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g N,N-methylenebisacrylamide and 0.01g potassium persulfate were added and the mixture was stirred to obtain a homogeneous precursor.

[0050] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining a ternary crosslinked hydrogel electrolyte of polyacrylamide-konjac gum-sodium carboxymethyl cellulose.

[0051] Example 3

[0052] 1g acrylamide, 0.1g locust bean gum and 0.1g sodium carboxymethyl cellulose were added sequentially to 10ml deionized water and magnetically stirred for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g N,N-methylenebisacrylamide and 0.01g potassium persulfate were added and the mixture was stirred to obtain a homogeneous precursor.

[0053] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining a ternary crosslinked hydrogel electrolyte of polyacrylamide-locust bean gum-sodium carboxymethyl cellulose.

[0054] Example 4

[0055] 1g acrylamide, 0.1g konjac gum and 0.1g sodium alginate were added sequentially to 10ml deionized water and magnetically stirred for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g N,N-methylenebisacrylamide and 0.01g potassium persulfate were added and the mixture was stirred to obtain a homogeneous precursor.

[0056] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining a ternary crosslinked hydrogel electrolyte of polyacrylamide-konjac gum-sodium alginate.

[0057] Example 5

[0058] 0.7g acrylamide, 0.25g soluble starch and 0.25g sodium carboxymethyl cellulose were added sequentially to 10ml deionized water and magnetically stirred for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g N,N-methylenebisacrylamide and 0.01g potassium persulfate were added and the mixture was stirred to obtain a homogeneous precursor.

[0059] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining a ternary crosslinked hydrogel electrolyte of polyacrylamide-soluble starch-sodium carboxymethyl cellulose.

[0060] Example 6

[0061] 0.8g acrylamide, 0.2g soluble starch and 0.2g sodium carboxymethyl cellulose were added sequentially to 10ml deionized water and magnetically stirred for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g N,N-methylenebisacrylamide and 0.01g potassium persulfate were added and the mixture was stirred to obtain a homogeneous precursor.

[0062] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining a ternary crosslinked hydrogel electrolyte of polyacrylamide-soluble starch-sodium carboxymethyl cellulose.

[0063] Example 7

[0064] 1g of acrylamide and 0.2g of sodium carboxymethyl cellulose were added sequentially to 10ml of deionized water and stirred magnetically for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. Next, 0.005g of N,N-methylenebisacrylamide and 0.01g of potassium persulfate were added and the mixture was stirred continuously to obtain a homogeneous precursor.

[0065] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining polyacrylamide-carboxymethyl cellulose sodium hydrogel electrolyte.

[0066] Example 8

[0067] 1g of acrylamide and 0.2g of soluble starch were added sequentially to 10ml of deionized water and stirred magnetically for 3h. Then, the mixture was ultrasonically dispersed for 0.5h to remove air bubbles. 0.005g of N,N-methylenebisacrylamide and 0.01g of potassium persulfate were added and the mixture was stirred continuously to obtain a homogeneous precursor.

[0068] After the precursor was poured into a mold, it was reacted in a forced-air oven at 60°C for 3 hours. After natural cooling, the reaction product was immersed in a mixed solution of 2 mol / L zinc sulfate and 0.2 mol / L manganese sulfate for 4 hours to swell, thus obtaining polyacrylamide-soluble starch hydrogel electrolyte.

[0069] Comparative Example 1

[0070] 57.512g ZnSO4·7H2O and 3.18g MnSO4·H2O were added sequentially to 80ml of deionized water and stirred magnetically for 3h, followed by ultrasonic dispersion for 0.5h to obtain a homogeneous precursor.

[0071] The precursor was poured into a 100ml volumetric flask and brought to a final volume. The mixture was then stirred magnetically for 8 hours to obtain a transparent and homogeneous mixed solution of 2mol / L zinc sulfate and 0.2mol / L manganese sulfate, which was used as a control for the liquid electrolyte.

[0072] Example 9

[0073] Electrochemical performance testing:

[0074] The ternary cross-linked hydrogel electrolyte synthesized by the method of the present invention is cut into circular films with a diameter of 16 mm using a punch, and used as the electrolyte for coin cells.

[0075] The coin cell is assembled using a "sandwich" structure of positive electrode-electrolyte-negative electrode. Zinc is used as the negative electrode, and manganese dioxide as the positive electrode; the electrolyte is a 16mm hydrogel disc film synthesized by the method of this embodiment or 3-5 drops of mixed salt solution synthesized by the comparative method; and the coin cell is assembled.

[0076] Electrochemical performance was tested using a Shenzhen Xinwei BST-5V battery tester, with a charge / discharge voltage range of 0.8V to 1.8V (vs. Zn). 2+ / Zn), the test temperature is 25℃.

[0077] Meanwhile, impedance testing was performed using a CHI660E electrochemical workstation from Shanghai Chenhua Co., Ltd., with a test frequency of 0.01–100,000 Hz.

[0078] Table 2 shows the electrochemical performance of the zinc-ion battery electrolytes prepared in Examples 1-8 and Comparative Example 1.

[0079] Table 2

[0080]

[0081] As shown in Table 2, the ternary cross-linked hydrogel electrolyte prepared in this invention exhibits stable electrochemical performance when applied to aqueous zinc-ion batteries. This is because the hydrogel in this invention introduces polysaccharide derivatives rich in hydroxyl groups. The hydroxyl groups in its cross-linked network structure, acting as hydrophilic groups, can effectively convert free water into bound water, reducing the activity of water in the system and minimizing side reactions caused by free water attacking the cathode material, thereby alleviating the problem of cathode material dissolution and collapse. Furthermore, the hydrogel in this invention introduces a polyanionic natural polymer containing carboxylate groups. The sodium carboxylate groups in its cross-linked network structure undergo ionic cross-linking with zinc ions, guiding uniform zinc deposition through ion confinement and reducing the formation of zinc dendrites. These three polymer raw materials exhibit a close synergistic effect; in the same system, the absence of any one of them will affect the electrochemical performance of the zinc-ion battery, reducing its effectiveness.

[0082] This invention explores the effects of different types of natural polymers on their electrochemistry by controlling different types of polysaccharide derivatives rich in hydroxyl groups and polyanionic natural polymers containing carboxylate groups. This allows for the selection of suitable natural polymers as raw materials. It can be seen that the technical effect achieved by using a ternary crosslinked hydrogel electrolyte of polyacrylamide-soluble starch-sodium carboxymethyl cellulose is the best.

[0083] Furthermore, by controlling different mass ratios of acrylamide, hydroxyl-rich polysaccharide derivatives, and carboxylate-containing polyanionic natural polymers, the effects of different mass ratios of the three polymer raw materials on their electrochemical performance can be explored. In this way, a suitable mass ratio of polymer raw materials can be selected to effectively improve the service life of aqueous zinc-ion batteries.

[0084] Figure 1 The image shows the microstructure of the hydrogel electrolyte prepared in Example 1 under a scanning electron microscope. As can be seen from the image, this invention successfully synthesized a hydrogel electrolyte with a three-dimensional porous network structure. This uniform and dense three-dimensional porous network structure provides Zn... 2+ The rapid transport channels within enable the zinc-ion battery to achieve a fast and reversible charge-discharge reaction process.

[0085] Figure 2The figure shows the stress-strain curve of the hydrogel electrolyte prepared in Example 1 under 99% mechanical compression deformation. As can be seen from the figure, the internal structure of the gel electrolyte does not break when the compression deformation reaches 99%. This excellent mechanical resilience is far superior to that of traditional glass fiber membranes, making it less likely for zinc dendrites to puncture the electrolyte membrane and cause a short circuit.

[0086] Figure 3 This is a comparison graph of the hydrogel electrolyte prepared in Example 1 and the liquid electrolyte under the same conditions in a zinc-ion battery at a current density of 1 A / g. Under 1000 cycles of high current density charge-discharge cycling, the zinc-ion battery assembled with the hydrogel electrolyte has a significant capacity retention advantage compared with the liquid electrolyte, and there is a relatively obvious activation process before 100 cycles, which is consistent with the CV curve.

[0087] Figure 4 The image shows a comparison of the XRD pattern of the zinc plate surface after 300 charge-discharge cycles in a zinc-ion battery using the hydrogel electrolyte prepared in Example 1, and the pattern of the liquid electrolyte under the same conditions. The diffraction pattern of the zinc plate surface in the zinc-ion battery assembled with this hydrogel electrolyte after 300 charge-discharge cycles perfectly matches the standard card for metallic zinc, with almost no byproduct formation. In contrast, the zinc-ion battery using a conventional electrolyte produces obvious byproduct Zn4(OH)6SO4·5H2O on the zinc plate surface after 300 charge-discharge cycles, matching the byproduct standard card (PDF#39-0688). This demonstrates that the hydrogel electrolyte of this invention effectively suppresses the occurrence of side reactions on the zinc anode surface.

[0088] Figure 5 The ionic conductivity of the hydrogel electrolyte prepared in Example 1 was measured by AC impedance spectroscopy and calculated to be 24.05 mS / cm, which is better than the ionic conductivity of most reported gel electrolytes. This indicates that the gel electrolyte can help zinc-ion batteries achieve fast and reversible charge-discharge reaction kinetics.

[0089] Figure 6 The CV curve of the hydrogel electrolyte prepared in Example 1 was obtained by cyclic voltammetry in a zinc-ion battery. Two pairs of redox peaks can be clearly observed. The peak current of the redox peaks gradually increases from the first to the fourth scan, indicating that the hydrogel electrolyte is a gradually activated process in the initial electrochemical reaction.

[0090] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a ternary crosslinked hydrogel electrolyte, characterized in that: include, Preparation of precursor: Acrylamide, hydroxyl-rich polysaccharide derivatives and carboxylate-containing polyanionic natural polymers are added sequentially to deionized water and stirred. The mixture is then ultrasonically dispersed to remove air bubbles. Finally, a crosslinking agent and an initiator are added and stirred to obtain a homogeneous precursor. Preparation of ternary cross-linked hydrogel electrolyte: After the precursor is poured into a mold, it is heated to initiate a free radical polymerization reaction. After the cross-linking polymerization is completed, it is immersed in a salt solution to reach swelling equilibrium, thus obtaining the ternary cross-linked hydrogel electrolyte. The hydroxyl-rich polysaccharide derivatives include one or more of soluble starch, locust bean gum, konjac gum, chitosan, xanthan gum, and carrageenan. The carboxylate-containing polyanionic natural polymer includes one or more of sodium alginate, sodium carboxymethyl cellulose, and sodium carboxymethyl starch. The crosslinking agent includes one or more of N,N-methylenebisacrylamide, polyethylene glycol diacrylate, and dicumyl peroxide; The initiator includes one or more of potassium persulfate and ammonium persulfate; The salt solution is a mixed solution of 0.1~5 mol / L zinc sulfate and 0.01~2 mol / L manganese sulfate; The mass ratio of the ternary combination of acrylamide, hydroxyl-rich polysaccharide derivatives, and carboxylate-containing polyanionic natural polymer is 1:0.01~0.5:0.01~0.

5.

2. The preparation method of the ternary crosslinked hydrogel electrolyte as described in claim 1, characterized in that: The acrylamide in the hydrogel system is 0.2% to 20% by mass; the polysaccharide derivative in the hydrogel system is 0.01% to 10% by mass; and the carboxylate-containing polyanionic natural polymer in the hydrogel system is 0.01% to 10% by mass.

3. The method for preparing the ternary crosslinked hydrogel electrolyte as described in claim 1 or 2, characterized in that: The crosslinking agent has a mass percentage of 0.001–10% in the hydrogel system; the initiator has a mass percentage of 0.001–10% in the hydrogel system.

4. The preparation method of the ternary crosslinked hydrogel electrolyte as described in claim 3, characterized in that: The preparation of the precursor involves magnetic stirring for 0.1 to 120 hours and ultrasonic dispersion for 0.1 to 5 hours.

5. The preparation method of the ternary crosslinked hydrogel electrolyte as described in claim 3, characterized in that: The preparation of the ternary cross-linked hydrogel electrolyte involves heating at a temperature of 50-100°C for 0.1-72 h and swelling for 0.2-96 h.

6. The product obtained by the preparation method of the ternary crosslinked hydrogel electrolyte according to any one of claims 1 to 5.

7. The application of the product according to claim 6 in the preparation of zinc-ion batteries, characterized in that: include, A zinc-ion battery is assembled using a positive electrode-electrolyte-negative electrode "sandwich" structure and a ternary cross-linked hydrogel system as the electrolyte.

8. The application as described in claim 7, characterized in that: The negative electrode includes metallic zinc, and the positive electrode material includes one or more of manganese-based, vanadium-based, and cobalt-based materials.

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