Zinc ion battery gel electrolyte and preparation method and application thereof

Abstract

The application belongs to the technical field of aqueous zinc ion battery, and discloses a zinc ion battery gel electrolyte and a preparation method and application thereof.A preparation method of the zinc ion battery gel electrolyte comprises the following steps: adding a propylene derivative and cellulose into an electrolyte solution, stirring uniformly to obtain a solution A; adding inorganic nanoparticles into the solution A, dispersing uniformly to obtain a solution B; adding an initiator and a crosslinking agent into the solution B, stirring uniformly, defoaming, and polymerizing in a mold to obtain the zinc ion battery gel electrolyte.The preparation method of the gel electrolyte is simple, low in cost, and has good mechanical properties, corrosion resistance, electrochemical properties and cycle stability, and the zinc ion battery assembled therefrom can be stably cycled for more than 1000 hours, so that the gel electrolyte is high in safety and efficiency and stability, and has an important application prospect in the zinc ion battery.

Description

Technical Field

[0001] This invention belongs to the field of aqueous zinc-ion battery technology, specifically relating to a zinc-ion battery gel electrolyte, its preparation method, and its application. Background Technology

[0002] Faced with the increasingly severe energy crisis and environmental pollution problems, the development of renewable energy and its storage technologies has become particularly urgent. Lithium-ion batteries, due to their high energy density and cycle stability, have been widely used in consumer electronics, transportation, and other fields. However, lithium-ion batteries currently face problems such as high cost, low safety, and the depletion of lithium resources, prompting researchers to continuously search for alternatives. Aqueous zinc-ion batteries have attracted widespread attention due to their low cost, high safety, environmental friendliness, and abundant zinc resources.

[0003] Despite the numerous advantages of aqueous zinc-ion batteries, several issues hinder their large-scale application. In particular, the zinc anode in aqueous liquid electrolytes suffers from severe side reactions such as dendrite growth, hydrogen evolution, corrosion, and passivation, significantly impacting battery life and posing a risk of leakage. Gel electrolytes, typically composed of a polymer matrix and a solution containing electrolyte salts, are an electrolyte that lies between liquid and solid states. The polymer matrix forms a three-dimensional network structure, whose internal porous structure can trap the liquid electrolyte, effectively preventing leakage. Simultaneously, it improves the zinc anode-electrolyte interface, transforming the solid-liquid interface into a solid-solid interface, avoiding direct contact between water and the zinc anode, and effectively solving problems such as zinc dendrite formation and interfacial side reactions. Therefore, gel electrolytes hold great promise for the large-scale application of zinc-ion batteries.

[0004] However, existing gel electrolytes, such as polyacrylamide, polyvinyl alcohol, polyoxyethylene, xanthan gum, gelatin, and sodium alginate, all suffer from low ionic conductivity and poor electrochemical activity, especially since their ionic conductivity is approximately 10. -4 ~10 -1 The S / cm ratio is lower than that of liquid electrolytes, limiting the charge / discharge rate and overall performance of the battery. Therefore, designing and developing a gel electrolyte that meets the application requirements of zinc-ion batteries is of great significance.

[0005] Patent CN118281372A discloses a cellulose / sodium alginate composite gel electrolyte membrane and its preparation method. The method involves mixing and aging cellulose and sodium alginate to obtain a composite hydrogel, which is then freeze-dried and immersed in an electrolyte solution to obtain the composite gel electrolyte membrane. The resulting electrolyte exhibits good stability, liquid retention capacity, and ionic conductivity. However, the above method requires freeze-drying, which is a complex process, and also necessitates immersion in an electrolyte solution for ion exchange, increasing time costs.

[0006] Patent CN118772445A discloses a modified hydrogel electrolyte for quasi-solid-state zinc-ion batteries and its preparation method. By introducing tetramethylurea into polyvinyl alcohol, the mechanical properties and corrosion resistance of the electrolyte are improved, enabling the electrolyte material to better resist physical stress and chemical corrosion during use, thereby extending the battery's lifespan. However, the organic zinc salt used in the gel electrolyte prepared by this patent is expensive, resulting in high costs and hindering practical production.

[0007] Patent TWI750909(B) discloses a hydrogel, its preparation method, a hydrogel electrolyte, a supercapacitor, and a battery. The preparation method of the hydrogel electrolyte includes the following steps: (1) preparing vinylsilane nanoparticles by reacting tetraethoxysilane and vinyltriethoxysilane in ammonia water, then adding (N,N-dimethyl-3-aminopropyl)trimethoxysilane and drying in argon to prepare zwitterionic surface-treated inorganic nanoparticles; (2) mixing the zwitterionic surface-treated inorganic nanoparticles prepared in step (1) with sulfonate betaine and deoxygenating with nitrogen to obtain solution A; (3) adding ammonium persulfate to solution A and heating to polymerize to obtain a gel electrolyte. This invention introduces zwitterionic surface-treated inorganic nanoparticles into a zwitterionic polymer framework to achieve high mechanical strength, broaden the electrochemical window, increase ionic conductivity, and suppress self-discharge rate. However, the preparation method provided by this technical solution is cumbersome, complex, requires inert gas protection, and is costly, making it unsuitable for actual production.

[0008] Patent US11942598(B2) discloses an ionic liquid-softened polymer electrolyte for zinc-ion batteries. It describes a method for preparing an electrolyte film by mixing an ionic liquid, nano-zinc oxide, polyethylene oxide, and an organozinc salt, followed by hot pressing. This invention uses an ionic liquid as a plasticizer and adds nano-zinc oxide filler to increase the amorphous phase in the polyethylene oxide, thereby improving the ionic conductivity and mechanical properties of the electrolyte. However, the polymer electrolyte prepared by this patent exhibits a low ionic conductivity of only 0.5 × 10⁻⁶. -4 The S / cm ratio is much lower than that of liquid electrolytes, making it difficult to meet the application requirements of zinc-ion batteries.

[0009] Therefore, providing a gel electrolyte with simple processing, excellent electrochemical performance, good mechanical properties, and high efficiency and stability has broad application prospects. Summary of the Invention

[0010] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a method for preparing a zinc-ion battery gel electrolyte.

[0011] Another object of the present invention is to provide a zinc-ion battery gel electrolyte.

[0012] Another object of the present invention is to provide the application of the above-mentioned gel electrolyte in zinc-ion batteries.

[0013] Another object of the present invention is to provide a zinc-ion battery.

[0014] The objective of this invention is achieved through the following technical solution:

[0015] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0016] (1) Add propylene derivatives and cellulose to an electrolyte solution and stir until homogeneous to obtain solution A;

[0017] (2) Add inorganic nanoparticles to solution A and disperse them evenly to obtain solution B;

[0018] (3) Add the initiator and crosslinking agent to solution B, stir evenly, remove bubbles, place in a mold for polymerization, and obtain zinc ion battery gel electrolyte.

[0019] Preferably, the inorganic nanoparticles are one or more of nano-silica, nano-alumina, nano-zinc oxide, nano-zirconia, or nano-titanium dioxide.

[0020] Preferably, the amount of inorganic nanoparticles added is 0.1-10% of the mass of the propylene derivative, more preferably 0.5-5%, and even more preferably 0.5-2.5%.

[0021] Preferably, the propylene derivative is one or more of acrylic acid, acrylamide, and methyl acrylate;

[0022] The cellulose is one or more of carboxymethyl cellulose, methyl cellulose, and hydroxyethyl methyl cellulose, and the amount of cellulose added is 1 to 10% of the mass of the propylene derivative.

[0023] Preferably, the electrolyte solution is a zinc salt solution, wherein the zinc salt is one or more of zinc sulfate, zinc nitrate, zinc chloride, zinc acetate or zinc trifluoromethanesulfonate, and the concentration of the electrolyte solution is 1-5 mol / L.

[0024] The crosslinking agent is one of N,N'-methylenebisacrylamide, polyethylene glycol, or N,N'-bis(acryloyl)cysteine;

[0025] The initiator is ammonium persulfate or potassium persulfate.

[0026] Preferably, the degassing in step (2) is vacuum degassing, and the degassing time is 0.1 to 0.5 hours;

[0027] The polymerization in step (3) is a thermal polymerization, with a polymerization temperature of 40 to 90°C and a polymerization time of 0.5 to 3 hours.

[0028] Preferably, the concentration of propylene derivative in solution A in step (1) is 100-500 g / L, more preferably 200 g / L;

[0029] The initiator concentration in solution B is 0.2-3 g / L, preferably 2 g / L, and the crosslinking agent concentration is 1-4 g / L, preferably 4 g / L.

[0030] A zinc-ion battery gel electrolyte is prepared by the method described above.

[0031] Preferably, the zinc-ion battery gel electrolyte is composed of a dual-network structure polymer matrix, inorganic nanoparticles, and an electrolyte solution. The dual-network structure polymer matrix is ​​a three-dimensional network framework with a polymer of propylene derivatives as the main body and cellulose as the guest network framework. The zinc-ion battery gel electrolyte fixes the electrolyte solution inside the gel.

[0032] Preferably, by mass percentage, the zinc-ion battery gel electrolyte comprises: 10-15% propylene derivative, 1-1.5% cellulose, 0.05-0.75% inorganic nanoparticles, 0.20-0.30% initiator, 0.10-0.15% crosslinking agent, and the balance being an electrolyte solution.

[0033] The application of the above-mentioned gel electrolyte in zinc-ion batteries.

[0034] A zinc-ion battery includes a positive electrode, a negative electrode, and an electrolyte, wherein the electrolyte is the zinc-ion battery gel electrolyte described above.

[0035] Preferably, the positive electrode contains a manganese-based compound, and the negative electrode is a zinc sheet.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] (1) Improve the mechanical properties and corrosion resistance of gel electrolytes

[0038] This invention introduces a guest network of carboxymethyl cellulose (CMC) onto the main three-dimensional network framework of acrylamide, constructing a gel with a dual-network structure. The dual-network polymer matrix effectively enhances molecular interactions, improves mechanical strength, and exhibits superior mechanical properties compared to a single-network gel electrolyte. The assembled battery shows a lower corrosion current, demonstrating superior corrosion resistance. Furthermore, the carboxyl groups on the CMC guide zinc ion migration and reduce water activity, achieving uniform zinc ion deposition, inhibiting zinc dendrite growth on the zinc anode, and increasing the cycle stability of the zinc anode. The current density is 1 mA / cm². 2The surface area capacity is 1mAh / cm². 2 Under these conditions, the assembled zinc / electrolyte / zinc battery can cycle stably for over 1000 hours at a current density of 5 mA / cm². 2 The surface area capacity is 1mAh / cm². 2 Under these conditions, it can still cycle stably for 400 hours, making it a highly safe, efficient, and stable gel electrolyte.

[0039] (2) Improve the ionic conductivity and ion transport number of gel electrolytes

[0040] This invention introduces inorganic nanoparticles, which on the one hand increase the amorphous regions in the polymer, promote polymer chain segment movement, and improve the ionic conductivity of the gel electrolyte; on the other hand, the space charge layer spontaneously formed at the interface between the inorganic particles and the polymer matrix can provide a fast channel for the transport of zinc ions, thereby increasing the ion transference number. The resulting gel electrolyte has excellent electrochemical performance.

[0041] (3) The preparation method is simple, the raw materials are readily available, and it is suitable for large-scale production.

[0042] The high-safety gel electrolyte of this invention requires readily available and widely sourced raw materials, and its preparation method is simple and easy to implement. By directly polymerizing in a salt solution, the electrolyte solution is fixed inside the gel, eliminating the need for prolonged immersion in the salt solution for ion exchange, thus shortening the preparation time and achieving high production efficiency. It is suitable for large-scale production and practical application. Attached Figure Description

[0043] Figure 1 Nyquist plots of stainless steel / / electrolyte / / stainless steel batteries assembled with electrolytes prepared in Examples 1-6 and Comparative Examples 1-3.

[0044] Figure 2 Nyquist plots of zinc / electrolyte / zinc batteries assembled from the electrolytes prepared in Examples 1-6 and Comparative Examples 1-3.

[0045] Figure 3 The tensile stress-strain curves are for the electrolytes prepared in Example 2 and Comparative Example 1.

[0046] Figure 4 Tafel curves were obtained for the electrolytes prepared in Example 2 and Comparative Example 1.

[0047] Figure 5 The zinc / electrolyte / zinc battery assembled using the electrolytes prepared in Example 2 and Comparative Example 1 operates at a current density of 1 mA / cm². 2 The surface area capacity is 1mAh / cm². 2 The cyclic test diagram under the given conditions.

[0048] Figure 6 The zinc / electrolyte / zinc battery assembled using the electrolytes prepared in Example 2 and Comparative Example 1 operates at a current density of 5 mA / cm². 2 The surface area capacity is 1mAh / cm². 2 The cyclic test diagram under the given conditions.

[0049] Figure 7 The zinc / electrolyte / zinc battery assembled using the electrolytes prepared in Example 2 and Comparative Example 1 operates at a current density of 1 mA / cm². 2 The surface area capacity is 1mAh / cm². 2 Microscopic morphology of zinc anode after 100 charge-discharge cycles under certain conditions, as shown in the scanning electron microscope.

[0050] Figure 8 The specific capacity diagram shows the zinc / electrolyte / MnO2 batteries assembled with the electrolytes prepared in Example 2 and Comparative Examples 1-2. Detailed Implementation

[0051] 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.

[0052] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0053] Example 1

[0054] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0055] 2g of acrylamide and 0.2g of carboxymethyl cellulose were added sequentially to 10mL of a solution containing 1mol / L zinc sulfate and stirred thoroughly. Then, 10mg of nano-titanium dioxide was added and stirred until homogeneous. The amount added was 0.5% of the mass of the monomeric acrylamide. 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate were added and stirred to obtain a homogeneous suspension. Subsequently, air bubbles were removed under vacuum.

[0056] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0057] Example 2

[0058] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0059] 2g of acrylamide and 0.2g of carboxymethyl cellulose were added sequentially to 10mL of a solution containing 1mol / L zinc sulfate and stirred thoroughly. Then, 30mg of nano titanium dioxide was added and stirred until homogeneous. The amount added was 1.5% of the mass of the monomeric acrylamide. 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate were added and stirred to obtain a homogeneous suspension. Subsequently, air bubbles were removed under vacuum.

[0060] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0061] Example 3

[0062] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0063] 2g of acrylamide and 0.2g of carboxymethyl cellulose were added sequentially to 10mL of a solution containing 1mol / L zinc sulfate and stirred thoroughly. Then, 50mg of nano titanium dioxide was added and stirred until the mixture was homogeneous. The amount added was 2.5% of the mass of the monomeric acrylamide. Then, 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate were added and stirred to obtain a homogeneous suspension. Subsequently, the air bubbles were removed under vacuum.

[0064] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0065] Example 4

[0066] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0067] 2g of acrylamide and 0.2g of carboxymethyl cellulose were added sequentially to 10mL of a solution containing 1mol / L zinc sulfate and stirred thoroughly. Then, 10mg of nano zinc oxide was added and stirred until the mixture was homogeneous. The amount added was 0.5% of the mass of the monomeric acrylamide. Then, 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate were added and stirred to obtain a homogeneous suspension. Subsequently, the air bubbles were removed under vacuum.

[0068] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0069] Example 5

[0070] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0071] 2g of acrylamide and 0.2g of carboxymethyl cellulose were added sequentially to 10mL of a solution containing 1mol / L zinc sulfate and stirred thoroughly. Then, 10mg of nano-silica was added and stirred until the mixture was homogeneous. The amount added was 0.5% of the mass of the monomeric acrylamide. Then, 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate were added and stirred to obtain a homogeneous suspension. Subsequently, the air bubbles were removed under vacuum.

[0072] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0073] Example 6

[0074] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0075] 2g of acrylamide and 0.2g of carboxymethyl cellulose were added sequentially to 10mL of a solution containing 2mol / L zinc sulfate and stirred thoroughly. Then, 10mg of nano titanium dioxide was added and stirred until the mixture was homogeneous. The amount added was 0.5% of the mass of the monomeric acrylamide. Then, 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate were added and stirred to obtain a homogeneous suspension. Subsequently, the air bubbles were removed under vacuum.

[0076] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0077] Comparative Example 1

[0078] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0079] Add 2g of acrylamide to 10mL of a solution containing 1mol / L zinc sulfate and stir thoroughly until homogeneous. Then add 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate and stir to obtain a homogeneous solution. Subsequently, remove air bubbles under vacuum.

[0080] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0081] Comparative Example 2

[0082] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0083] Add 2g of acrylamide and 0.2g of carboxymethyl cellulose to 10mL of a solution containing 1mol / L zinc sulfate and stir thoroughly until homogeneous. Then add 40mg of N,N'-methylenebisacrylamide and 20mg of potassium persulfate and stir to obtain a homogeneous solution. Subsequently, remove air bubbles under vacuum.

[0084] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0085] Comparative Example 3

[0086] A method for preparing a zinc-ion battery gel electrolyte includes the following steps:

[0087] 2g acrylamide, 0.2g carboxymethyl cellulose, and 30mg trisodium citrate were added sequentially to 10mL of a solution containing 1mol / L zinc sulfate and stirred thoroughly until homogeneous. Then, 40mg N,N'-methylenebisacrylamide and 20mg potassium persulfate were added and stirred to obtain a homogeneous solution. Subsequently, the solution was vacuum-sealed to remove air bubbles.

[0088] The suspension was poured into a mold and heated at 70°C for 2 hours to initiate monomer polymerization, yielding a gel electrolyte.

[0089] Application examples

[0090] A method for preparing a zinc-ion battery includes the following steps:

[0091] (1) Preparation of cathode materials:

[0092] 0.1 mol KMnO4 and 0.15 mol Mn(CH3COO)2·4H2O were dissolved in 100 mL of deionized water, respectively. The Mn(CH3COO)2 solution was slowly added to the KMnO4 solution at room temperature, and the reaction was stirred for 4 h. The mixture was then washed three times alternately by centrifugation with deionized water and anhydrous ethanol to obtain a brownish-black precipitate. This precipitate was dried under vacuum at 80 °C for 10 h to obtain the final product, MnO2.

[0093] (2) Preparation of the positive electrode sheet:

[0094] The positive electrode material, carbon nanotubes, and polyvinylidene fluoride were dispersed in an N-methylpyrrolidone solution at a mass ratio of 7:2:1 to form a uniform suspension. The suspension was then coated onto stainless steel using a blade coating method and vacuum dried at 60°C for 3 hours to obtain the positive electrode sheet.

[0095] (3) Preparation of full cells:

[0096] A full cell was assembled from MnO2 positive electrode, gel electrolyte, and zinc metal negative electrode, and charge-discharge tests were conducted.

[0097] Performance testing

[0098] Assemble a stainless steel / electrolyte / stainless steel symmetric cell and measure electrochemical impedance spectroscopy (EIS) using an electrochemical workstation (CS2350M), setting the frequency range to 10. -2 ~106 Hz, calculate ionic conductivity using the following formula

[0099]

[0100] In Formula 1, L is the thickness of the gel electrolyte, R is the battery impedance, and S is the electrode area.

[0101] Figure 1 The Nyquist plots are for stainless steel / / electrolyte / / stainless steel batteries assembled with electrolytes prepared in Examples 1-6 and Comparative Examples 1-3. The intersection of the curves with the horizontal axis represents the battery impedance.

[0102] Assemble a zinc / electrolyte / zinc battery, and calculate the zinc ion transport number by measuring the impedance and response current of the symmetrical cell before and after polarization using the following formula:

[0103]

[0104] In Formula 2, I o R is the initial response current. o Let I be the initial impedance. s For steady-state current, R s ΔV is the steady-state impedance, and ΔV is the polarization voltage.

[0105] Figure 2 Nyquist plots are shown for the zinc / electrolyte / zinc batteries assembled in Examples 1-6 and Comparative Examples 1-3. The ionic conductivity and zinc ion transport number results for Examples 1-6 and Comparative Examples 1-3, calculated using Formulas 1 and 2, are shown in Table 1.

[0106] Table 1

[0107] Ionic conductivity (mS / cm) Zinc ion transport number Example 1 31.0 0.54 Example 2 32.6 0.63 Example 3 28.2 0.50 Example 4 14.9 0.67 Example 5 20.5 0.37 Example 6 45.5 0.22 Comparative Example 1 10.1 0.33 Comparative Example 2 19.9 0.47 Comparative Example 3 26.7 0.34

[0108] Table 1 shows that adding different nanoparticles can improve the ionic conductivity and zinc ion transference number of the gel electrolyte. However, different nanoparticles have different effects on the electrochemical performance of the gel electrolyte. When the amount of nanoparticles added is the same, the ionic conductivity of Example 1 with nano-titanium dioxide is 31.0 mS / cm, which is higher than that of Example 4 with nano-zinc oxide (14.9 mS / cm) and Example 5 with nano-silica (20.5 mS / cm). This is because nano-titanium dioxide can provide more ion channels, increasing the ionic conductivity of the electrolyte. Different nanoparticle contents also affect the performance of the electrolyte. The increase in ionic conductivity is limited when the amount added is small, while the amount added may cause the nanoparticles to agglomerate, resulting in uneven particle distribution, which is not conducive to ion transport. By comparing Examples 1-5, it can be seen that Example 2, with nano-titanium dioxide added at 1.5% of the monomer mass, has the best electrochemical performance, with an ionic conductivity of 32.6 mS / cm and a zinc ion transference number of 0.63.

[0109] The samples were made into dumbbell shapes, and the fracture strength and elongation at break of the gel electrolytes prepared in Example 2 and Comparative Example 1 were tested using an electronic universal testing machine. Their tensile stress-strain curves are shown below. Figure 3 As shown, by Figure 3 It can be seen that the tensile strength of the dual-network gel electrolyte prepared in Example 2 is as high as 40.85 kPa, which is much higher than the 3.80 kPa of the single-network gel electrolyte prepared in Comparative Example 1. At the same time, the dual-network gel electrolyte prepared in Example 2 also has an elongation at break of 434%, showing excellent mechanical properties.

[0110] Example 2 and Comparative Example 1 were assembled into zinc metal / electrolyte / zinc metal symmetric cells, and Tafel tests were performed on them using an electrochemical workstation. The test results are as follows: Figure 4 As shown, the battery assembled with the gel electrolyte prepared in Example 2 exhibits a lower corrosion current compared to the battery assembled with the single-network gel electrolyte in Comparative Example 1, demonstrating its superior corrosion resistance.

[0111] The electrolytes prepared in Comparative Example 1 and Example 2 were assembled into zinc / electrolyte / zinc batteries, and tested at a current density of 1 mA / cm². 2 The surface area capacity is 1mAh / cm². 2 and current density 5 mA / cm 2 The surface area capacity is 1mAh / cm². 2 Under the specified conditions, the battery's cycle performance was tested at room temperature, and the results are as follows: Figure 5 and Figure 6 As shown.

[0112] from Figure 5 It can be seen that at a current density of 1 mA / cm² 2 The surface area capacity is 1mAh / cm². 2 Under the same conditions, the battery used in Comparative Example 1 failed in less than 400 hours. The battery then swelled, disconnecting the positive and negative terminals, and the voltage increased beyond its range. In contrast, the battery used in Example 2 exhibited excellent cycle stability, maintaining stable cycling for over 1000 hours. Figure 6 It can be seen that when using a larger current density (current density 5 mA / cm²), 2 The surface area capacity is 1mAh / cm². 2 During cycle testing, the battery using Example 2 could still cycle stably for 400 hours, while the battery using Comparative Example 1 experienced a short circuit after 125 hours of cycling. Furthermore, to demonstrate the inhibitory effect of the gel electrolyte constructed in this invention on dendrite growth, the surface of the zinc anode after cycling was characterized by scanning electron microscopy, and the results are as follows... Figure 7 As shown, the zinc anode using Comparative Example 1 exhibited poor surface smoothness and a large number of zinc dendrites. Comparison with the comparative example demonstrates that the gel electrolyte constructed in this invention can effectively suppress zinc dendrite growth, reduce parasitic reactions competing with zinc deposition, and achieve more uniform zinc deposition during battery cycling.

[0113] A zinc / electrolyte / MnO2 battery was assembled and charged / discharge tested at room temperature with a current density of 1 A / g. The cutoff voltage range was 0.5–1.9 V. The test results are as follows: Figure 8 As shown. From Figure 8 As can be seen, the battery assembled with the gel electrolyte prepared in Example 2 of this invention has a high specific capacity of 185 mAh / g during the first discharge, while the battery assembled with the single-network gel electrolyte prepared in Comparative Example 1 only has a specific capacity of 172 mAh / g during the first discharge. The battery assembled with the gel electrolyte in Example 2 still has a specific capacity of 116 mAh / g after 500 cycles, while the battery assembled with the single-network gel electrolyte experiences rapid capacity decay and short circuits before 200 cycles, leading to battery failure. This is mainly because, compared with Comparative Example 1, the electrolyte in Example 2 has higher ionic conductivity, higher zinc ion transport number, and better mechanical properties, thus significantly improving the cycle performance of aqueous zinc-ion batteries.

[0114] The above embodiments are merely preferred embodiments of the present invention. The scope of the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method of preparing a zinc-ion battery gel electrolyte, characterized in that, The method comprises the following steps: (1) adding acrylamide and carboxymethyl cellulose into an electrolyte solution, stirring uniformly to obtain solution A; (2) adding inorganic nanoparticles into solution A, dispersing uniformly to obtain solution B; (3) adding an initiator and a crosslinking agent into solution B, stirring uniformly, removing bubbles, and polymerizing in a mold to obtain a zinc ion battery gel electrolyte; The inorganic nanoparticles are nanometer titanium dioxide, and the addition amount of the inorganic nanoparticles is 0.5-2.5% of the mass of acrylamide; The electrolyte solution is a zinc salt solution.

2. The method of preparing a zinc-ion battery gel electrolyte according to claim 1, wherein, The addition amount of the carboxymethyl cellulose is 1-10% of the mass of acrylamide.

3. The method of producing a zinc ion battery gel electrolyte according to any one of claims 1 to 2, characterized by, The zinc salt is one or two or more of zinc sulfate, zinc nitrate, zinc chloride, zinc acetate or zinc trifluoromethane sulfonate, and the concentration of the electrolyte solution is 1-5 mol / L; The crosslinking agent is N,N'-methylene bisacrylamide or N,N'-bis(acryloyl)cystamine; The initiator is ammonium persulfate or potassium persulfate.

4. The method of preparing a zinc-ion battery gel electrolyte according to claim 3, wherein, The bubble removal in step (3) is vacuum bubble removal, and the bubble removal time is 0.1-0.5 hours; The polymerization in step (3) is thermal polymerization, the polymerization temperature is 40-90℃, and the polymerization time is 0.5-3 hours.

5. The method for preparing the zinc ion battery gel electrolyte according to claim 1, wherein, The concentration of acrylamide in solution A in step (1) is 100-500 g / L; After the initiator and the crosslinking agent are added into solution B in step (3), the concentration of the initiator is 0.2-3 g / L, and the concentration of the crosslinking agent is 1-4 g / L.

6. A zinc-ion battery gel electrolyte characterized in that, The zinc ion battery gel electrolyte is prepared by the method according to any one of claims 1-5.

7. The zinc ion battery gel electrolyte according to claim 6 is applied to a zinc ion battery.

8. A zinc-ion battery comprising a positive electrode, a negative electrode, and an electrolyte, characterized in that, The electrolyte is the zinc ion battery gel electrolyte according to claim 6.

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