Stretchable in-situ infused double network hydrogel electrolyte and preparation method and application thereof

Abstract

The application provides a stretchable in-situ soaked double-network hydrogel electrolyte and a preparation method and application thereof. The method comprises the following steps: preparing a uniform mixed solution of a first monomer, a second monomer, an initiator, a crosslinking agent and an accelerator; adjusting the pH value of the mixed solution, and obtaining a precursor solution after uniform stirring; removing bubbles in the precursor solution, and performing free radical polymerization at a preset temperature to form a hydrogel; cutting the hydrogel, adding a trace amount of a salt solution containing zinc ions to both sides of the cut hydrogel, and clamping the hydrogel between two pole pieces for in-situ soaking to obtain a hydrogel electrolyte. The independent hydrogel electrolyte can inhibit the side reaction on the surface of a zinc negative electrode, the growth of dendrites and the corrosion of the electrode, and simultaneously improve the electrochemical performance of a zinc ion battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water-based zinc ion battery polymer electrolyte, in particular to a stretchable in-situ soaked double-network hydrogel electrolyte, a preparation method and application thereof. BACKGROUND

[0002] In the process of pursuing the vision of net zero emissions, the combination of energy storage and carbon-free sustainable generators plays an indisputable role. Rechargeable lithium batteries have been widely used in industry due to their high energy density, long cycle life and other advantages. However, the scarcity of lithium reservoirs, the safety problems of non-aqueous electrolytes and high costs have restricted its future development. Water-based zinc ion batteries (ZIB) have the advantages of high theoretical capacity, low redox potential, high safety, low cost and low toxicity, and their simple structure, high specific capacity and energy density make them considered as the most promising alternative battery.

[0003] Electrolytes are one of the key components in ion batteries that control the reaction mechanism and dynamics, and they include liquid, quasi-solid and solid electrolytes. Liquid electrolytes usually have the highest ionic conductivity among the three types of electrolytes, but their fluidity poses strict requirements on the packaging process of the battery, and the problems of leakage and evaporation still exist. Solid electrolytes alleviate the concerns of liquid electrolytes, but due to their low room temperature ionic conductivity and high interfacial resistance, their electrochemical performance is far from satisfactory, and in addition, their brittleness limits large-scale production. Compared with liquid and solid electrolytes, quasi-solid electrolytes (i.e. hydrogel electrolytes) provide good ionic conductivity, interfacial performance and mechanical deformation capability, while having appropriate mechanical stiffness and elasticity, which can act as a separator to prevent dendrite growth and reduce the risk of short circuits. However, in existing research on hydrogel electrolytes applied to zinc ion batteries, high-strength hydrogels often have low ionic conductivity, and after soaking in a large amount of aqueous zinc salt solution, the mechanical properties will decrease and the battery performance will also decrease. SUMMARY

[0004] The present application aims to solve at least one of the above-mentioned deficiencies in the prior art. For example, one of the purposes of the present application is to provide a preparation method of a stretchable in-situ soaked double-network hydrogel electrolyte; the second purpose of the present application is to provide a stretchable in-situ soaked double-network hydrogel electrolyte; the third purpose of the present application is to provide a water-based zinc ion battery; the fourth purpose of the present application is to provide the application of the stretchable in-situ soaked double-network hydrogel electrolyte in the preparation of a battery.

[0005] To achieve the above-mentioned purposes, the first aspect of the present application provides a preparation method of a stretchable in-situ soaked double-network hydrogel electrolyte.

[0006] The method can comprise the following steps: preparing a uniform mixed solution of a first monomer, a second monomer, an initiator, a crosslinking agent and an accelerator; adjusting the pH value of the mixed solution, and after stirring uniformly, obtaining a precursor solution; removing bubbles in the precursor solution, and performing radical polymerization at a preset temperature to form a hydrogel; cutting the hydrogel, and adding a trace amount of a salt solution containing zinc ions on both sides of the cut hydrogel, and soaking the hydrogel in situ between two electrode plates to obtain a hydrogel electrolyte.

[0007] Alternatively, the first monomer is an amide monomer, the second monomer is an anhydride monomer, and the mass ratio of the first monomer to the second monomer is 1:(0.5-10).

[0008] The amide monomer can include one of acrylamide, methacrylamide, N-isopropyl acrylamide, N,N-diethyl acrylamide, isobutoxymethyl acrylamide, diacetone acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, 2-(trifluoromethylsulfonamido)ethyl-methacrylate and N-allyl-2,2,2-trifluoroacetamide and derivatives thereof.

[0009] The anhydride monomer can include one of maleic anhydride, succinic anhydride, bromomaleic anhydride, dimethyl maleate, diethyl maleate, dibutyl maleate, diisooctyl maleate, fumaric acid, fumaric acid dibutyl ester and fumaric acid bis(2-ethylhexyl) ester and derivatives thereof.

[0010] Alternatively, the initiator accounts for 0.2-2% of the total mass of the first monomer and the second monomer, and the initiator can include one of potassium persulfate, sodium persulfate, ammonium persulfate and azobisisobutyronitrile.

[0011] Alternatively, the crosslinking agent accounts for 0.01-1% of the total mass of the first monomer and the second monomer, and the crosslinking agent can include one or more of N,N'-methylenebisacrylamide, polyisobutylene acid ester, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester and ketone peroxide and derivatives thereof.

[0012] Alternatively, the accelerator accounts for 0.5-1% of the total mass of the first monomer and the second monomer, and the accelerator can include tetramethylethylenediamine.

[0013] Alternatively, the adjustment of the pH value of the mixed solution is performed by using a basic solution, the concentration of the basic solution is 0.01-2 mol / L, and the basic solution can include one of aqueous ammonia, aqueous sodium hydroxide solution, aqueous potassium hydroxide solution, aqueous sodium carbonate solution, aqueous sodium bicarbonate solution and aqueous triethylamine solution.

[0014] Optionally, the ultrasonic time under ice bath and nitrogen protection is 0.5-2h, the preset temperature is 30-65℃, and the polymerization time is 4-20h.

[0015] Optionally, the bubble removal in the precursor solution is achieved by ultrasonic removal under ice bath and nitrogen protection, and the ultrasonic time is 0.5-2h.

[0016] Optionally, the preset temperature is 30-65℃, and the polymerization time is 4-20h.

[0017] Optionally, the size of the hydrogel is cut into a round piece with a diameter of 12-18mm, the dropwise addition amount of the salt solution containing zinc ions is 10-40μL, the concentration of the salt solution containing zinc ions is 1-3mol / L, and the salt solution containing zinc ions can include one of zinc chloride, zinc sulfate, zinc trifluoromethyl sulfonate, zinc acetate and zinc perchlorate.

[0018] The second aspect of the present application provides a stretchable in-situ soaking double-network hydrogel electrolyte.

[0019] The stretchable in-situ soaking double-network hydrogel electrolyte can be prepared by the above method.

[0020] The third aspect of the present application provides a water-based zinc ion battery.

[0021] The water-based zinc ion battery includes the above-mentioned stretchable in-situ soaking double-network hydrogel electrolyte.

[0022] The fourth aspect of the present application provides the application of the above-mentioned stretchable in-situ soaking double-network hydrogel electrolyte in the preparation of a battery.

[0023] Compared with the prior art, the beneficial effects of the present application include at least one of the following:

[0024] (1) The hydrogel electrolyte prepared by the present application can improve the electrochemical performance of the hydrogel electrolyte in the application of zinc ion battery by adjusting the pH value of the precursor solution.

[0025] (2) The hydrogel electrolyte prepared by the present application greatly reduces the consumption of zinc salt, improves the utilization rate of zinc salt and ensures its application as electrolyte in zinc ion battery.

[0026] (3) The hydrogel electrolyte prepared by the present application can be independently applied in zinc ion battery, as electrolyte and also as separator, which can effectively inhibit the formation of dendrites.

[0027] (4) The prepared hydrogel electrolyte has good mechanical properties and ionic conductivity, the hydrophilic functional groups on the polymer chain can adsorb or limit active water, inhibit the precipitation of hydrogen and the formation of by-products, and optimize the diffusion of Zn 2+ ions, and inhibit the formation of dendrites.

[0028] (5) The prepared hydrogel electrolyte has excellent cycle stability when applied to a zinc ion battery, and exhibits a cycle stable voltage of 2000h in a Zn||Zn symmetric battery, and after 500 cycles at a current density of 1A / g, the capacity can still maintain 79.5%.

[0029] (6) The experimental steps for preparing the hydrogel electrolyte are simple and easy to operate, and promote the further development of the gel polymer electrolyte of the water-based zinc ion battery. BRIEF DESCRIPTION OF DRAWINGS

[0030] The above and other objects and / or characteristics of the present application will become more apparent by describing in detail the embodiments thereof with reference to the attached drawings, in which:

[0031] Figure 1 An optical photo of a stretchable in-situ soaked double network hydrogel electrolyte battery prepared by Example 5 of the present application is shown;

[0032] Figure 2 An optical photo of a stretchable in-situ soaked double network hydrogel electrolyte prepared by Example 5 of the present application under deformation is shown;

[0033] Figure 3 A voltage-time curve of a Zn||Zn symmetric battery composed of the stretchable in-situ soaked double network hydrogel electrolyte prepared by Example 5 and Comparative Example 1 of the present application at a current density of 1mA / cm 2

[0034] Figure 4 A long cycle performance graph of a full battery composed of the double network self-healing hydrogel electrolyte prepared by Example 5 and Comparative Example 1 of the present application is shown;

[0035] Figure 5 An ionic conductivity graph of an iron symmetric battery composed of the double network self-healing hydrogel electrolyte prepared by Example 5 and Comparative Example 1 of the present application is shown. DETAILED DESCRIPTION

[0036] In the following, the stretchable in-situ soaked double network hydrogel electrolyte and the preparation method and application thereof of the present application will be described in detail in conjunction with exemplary embodiments.

[0037] Exemplary Embodiment 1

[0038] ​The present exemplary embodiment provides a preparation method of a stretchable in-situ soaked double-network hydrogel electrolyte.

[0039] The preparation method can include the following steps:

[0040] S1, preparing a uniform mixed solution of a first monomer, a second monomer, an initiator, a crosslinking agent, and an accelerator.

[0041] In the present embodiment, the first monomer is an amide monomer, the second monomer is an anhydride monomer, and the mass ratio of the first monomer to the second monomer is 1:(0.5-10), such as 1:0.5, 1:0.7, 1:1, 1:5, 1:6, 1:9.8, etc.

[0042] Different monomer mass ratios result in different performances of the gel polymer electrolyte, and the application of gel polymer electrolytes with different monomer mass ratios in zinc ion batteries is explored to reflect the differences in electrochemical performance.

[0043] The amide monomer can include one of acrylamide, methacrylamide, N-isopropyl acrylamide, N,N-diethyl acrylamide, isobutoxymethyl acrylamide, diacetone acrylamide, 2-acrylamido-2-methylpropane sulfonic acid, 2-(trifluoromethylsulfonamido)ethyl-methacrylate, and N-allyl-2,2,2-trifluoroacetamide, and derivatives thereof.

[0044] The anhydride monomer can include one of maleic anhydride, succinic anhydride, bromomaleic anhydride, dimethyl maleate, diethyl maleate, dibutyl maleate, diisooctyl maleate, fumaric acid, fumaric acid dibutyl ester, and fumaric acid bis(2-ethylhexyl) ester, and derivatives thereof.

[0045] In the present embodiment, the initiator accounts for 0.2-2% of the sum of the mass of the first monomer and the second monomer, such as 0.2%, 0.5%, 0.6%, 1%, 1.2%, 1.9%, etc.

[0046] The initiator can include one of potassium persulfate, sodium persulfate, ammonium persulfate, and azobis isobutyronitrile.

[0047] Different initiators have different initiation modes, and different mass percentages of initiators result in different initiation rates of gel electrolytes. The types and mass percentages of initiators are explored to optimize the initiation mode and initiation rate of the gel electrolyte in the present system to adapt to more excellent electrochemical performance of zinc ion batteries.

[0048] In the present embodiment, the crosslinking agent accounts for 0.01-1% of the total mass of the first monomer and the second monomer, such as 0.01%, 0.02%, 0.06%, 0.1%, 0.2%, 0.5%, 0.95%, etc.

[0049] The crosslinking agent can include one or more of N,N'-methylenebisacrylamide, polyisobutylene acid ester, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester, and ketone peroxide, and derivatives thereof.

[0050] The present application selects two monomers to copolymerize to prepare a hydrogel electrolyte, different crosslinking methods of different crosslinking agents, and the mass percentage of different crosslinking agents will affect the crosslinking degree of the hydrogel. Based on this, it is hoped that by exploring the types and mass percentages of the crosslinking agents, a more suitable crosslinking method and crosslinking degree can be selected for application in the water-based zinc ion battery.

[0051] In the present embodiment, the accelerator accounts for 0.5-1% of the total mass of the first monomer and the second monomer, such as 0.5%, 0.55%, 0.6%, 0.7%, 0.72%, 0.8%, 0.98%, etc.

[0052] The accelerator can include tetramethyl ethylenediamine.

[0053] Among them, selecting tetramethyl ethylenediamine as the accelerator can improve the polymerization speed while forming a hydrogel with high mechanical strength and stability, and selecting the above mass percentage can reduce the side reaction between the monomer and the crosslinking agent, improve the purity and quality of the final product, and make its application in the zinc ion battery more advantageous.

[0054] S2, adjust the acidity and alkalinity of the mixed solution, and after stirring uniformly, a precursor solution is obtained.

[0055] In the present embodiment, an alkaline solution is used to adjust the acidity and alkalinity of the mixed solution, and the concentration of the alkaline solution is 0.01-2 mol / L, such as 0.01 mol / L, 0.02 mol / L, 0.05 mol / L, 0.1 mol / L, 0.2 mol / L, 1 mol / L, 1.2 mol / L, 1.9 mol / L, etc.

[0056] Among them, by adjusting the acidity and alkalinity of the hydrogel precursor solution of the present system, the physical and chemical properties of the hydrogel are optimized, which can improve the electrochemical performance of the hydrogel applied in the water-based zinc ion battery. After adjusting the acidity and alkalinity, the pH value of the precursor solution is 1.5-5.5, such as 1.5, 1.8, 2.1, 3.5, and 5.4, etc.

[0057] The alkaline solution can include one of aqueous ammonia, aqueous sodium hydroxide, aqueous potassium hydroxide, aqueous sodium carbonate, aqueous sodium bicarbonate, and aqueous triethylamine.

[0058] S3, removing bubbles in the precursor solution, free radical polymerization at a preset temperature to form a hydrogel.

[0059] In the embodiment, the removal of bubbles in the precursor solution is by ultrasonic removal under ice bath and nitrogen protection, and the ultrasonic duration is 0.5-2 h, such as 0.5 h, 0.55 h, 0.6 h, 0.8 h, 1 h, 1.2 h, 1.9 h, etc.

[0060] The oxygen in the hydrogel precursor solution can be completely removed within the above time range.

[0061] In the embodiment, the preset temperature is 30-65℃, such as 30℃, 32℃, 35℃, 40℃, 42℃, 50℃, 56℃, 60℃, 65℃, etc.

[0062] Different temperatures cause different speeds of initiating the hydrogel, and different crosslinking network structures are brought about, and the selection of the above temperature can better control the polymerization speed of the hydrogel system.

[0063] In the embodiment, the polymerization time is 4-20 h, such as 4 h, 4.5 h, 4.7 h, 6 h, 8.5 h, 12 h, 15.5 h, 19.5 h, etc.

[0064] The selection of the above time range can ensure that the precursor solution can be completely polymerized to be applied in the aqueous zinc ion battery.

[0065] S4, cutting the hydrogel, and adding a small amount of salt solution containing zinc ions to both sides of the cut hydrogel, and soaking in situ between two pole pieces to obtain a hydrogel electrolyte.

[0066] In the embodiment, the size of the cut hydrogel is a disc with a diameter of 12-18 mm, and the drop amount of the salt solution containing zinc ions is 10-40 μL, such as 10 μL, 11 μL, 15 μL, 20 μL, 25 μL, 30 μL, 39 μL, 40 μL, etc.

[0067] The concentration of the salt solution containing zinc ions is 1-3 mol / L, such as 1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.5 mol / L, 2 mol / L, 2.7 mol / L, 3 mol / L, etc.

[0068] The drop amount of the above salt solution is much smaller than the amount of electrolyte currently used in the aqueous zinc ion battery, which can save costs while ensuring its application in the aqueous zinc ion battery; the selected concentration of the salt solution belongs to a low concentration of zinc salt, and the application of the zinc ion battery on this basis is conducive to the migration of zinc ions, thereby bringing about more excellent electrochemical performance.

[0069] The salt solution containing zinc ions can include one of zinc chloride, zinc sulfate, zinc trifluoromethylsulfonate, zinc acetate, and zinc perchlorate.

[0070] Example Embodiment 2

[0071] The present example embodiment provides a stretchable in-situ soaking double network hydrogel electrolyte.

[0072] The stretchable in-situ soaking double network hydrogel electrolyte can be prepared by the method described in example embodiment 1.

[0073] Example Embodiment 3

[0074] The present example embodiment provides a water-based zinc ion battery.

[0075] The water-based zinc ion battery includes the stretchable in-situ soaking double network hydrogel electrolyte described in example embodiment 2.

[0076] Example Embodiment 4

[0077] The present example embodiment provides the use of a stretchable in-situ soaking double network hydrogel electrolyte in the preparation of a battery.

[0078] In order to better understand the above example embodiments, further description is made below in combination with specific embodiments.

[0079] Example 1

[0080] (1) 2 g of isobutoxymethyl acrylamide and 1 g of maleic acid diethyl ester were dissolved in 20 mL of deionized water, and stirred at room temperature until transparent, 0.03 g of potassium persulfate, 0.015 g of diacyl peroxide and 30 μL of tetramethyl ethylenediamine were added, and stirred at room temperature to obtain a mixed solution; (2) a 0.1 mol / L sodium bicarbonate aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 6, and after stirring uniformly, a precursor solution was obtained; (3) under ice bath and nitrogen protection, ultrasonic was performed for 30 min to remove bubbles in the precursor solution, and radical polymerization was performed at 80°C for 4 h to form a hydrogel; (4) the hydrogel was cut into a circular piece with a diameter of 18 mm, 40 μL of 1 mol / L zinc perchlorate aqueous solution was added dropwise on both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble into a complete battery.

[0081] Example 2

[0082] (1) 2.5 g of methacrylamide and 0.5 g of succinic anhydride were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of sodium persulfate, 0.015 g of polyisobutylene acid ester and 30 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) a 0.1 mol / L sodium hydroxide aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 5, and after stirring uniformly, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment under ice bath and nitrogen protection for 30 min, and the hydrogel was formed by radical polymerization at 80°C for 4 h; (4) the hydrogel was cut into a circular piece with a diameter of 16 mm, 40 μL of a 1 mol / L zinc sulfate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble a complete battery.

[0083] Example 3

[0084] (1) 2.5 g of N-isopropyl acrylamide and 0.5 g of bromine maleic anhydride were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of ammonium persulfate, 0.017 g of hydroperoxide and 30 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) a 0.1 mol / L potassium hydroxide aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 4, and after stirring uniformly, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment under ice bath and nitrogen protection for 30 min, and the hydrogel was formed by radical polymerization at 70°C for 8 h; (4) the hydrogel was cut into a circular piece with a diameter of 14 mm, 40 μL of a 1 mol / L zinc trifluoromethyl sulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble a complete battery.

[0085] Example 4

[0086] (1) 2.5 g of N,N-diethyl acrylamide and 0.5 g of dimethyl maleate were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of azobis isobutyl cyanide, 0.017 g of dialkyl peroxide and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) a 0.1 mol / L sodium carbonate aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment under ice bath and nitrogen protection for 30 min, and the hydrogel was formed by radical polymerization at 50°C for 12 h; (4) the hydrogel was cut into a circular piece with a diameter of 12 mm, 40 μL of a 1 mol / L zinc acetate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble a complete battery.

[0087] Example 5

[0088] (1) 2.5 g of acrylamide and 0.5 g of maleic anhydride were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of potassium persulfate, 0.017 g of N, N'-methylene bisacrylamide and 20 μL of tetramethyl ethylenediamine were added, and the mixture was stirred at room temperature to obtain a homogeneous solution; (2) ammonia water with a concentration of 0.1 mol / L was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment for 30 min under ice bath and nitrogen protection, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a circular piece with a diameter of 12 mm, 20 μL of zinc chloride aqueous solution with a concentration of 1 mol / L was added to both sides of the hydrogel and sandwiched between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble a complete battery, which can be seen from Figure 1 the optical photo of the assembled battery. Figure 2 the optical photo of the stretchable in-situ soaked double network hydrogel electrolyte prepared according to Example 5 under deformation, Figure 2 the upper half is before deformation, and the lower half is after deformation.

[0089] Example 6

[0090] (1) 2.5 g of diacetone acrylamide and 0.5 g of maleic acid dibutyl ester were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of sodium persulfate, 0.017 g of peroxide ester and 20 μL of tetramethyl ethylenediamine were added, and the mixture was stirred at room temperature to obtain a homogeneous solution; (2) peroxide ester with a concentration of 0.1 mol / L was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment for 30 min under ice bath and nitrogen protection, and the hydrogel was formed by radical polymerization at 40°C for 16 h; (4) the hydrogel was cut into a circular piece with a diameter of 12 mm, 20 μL of zinc chloride aqueous solution with a concentration of 1 mol / L was added to both sides of the hydrogel and sandwiched between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble a complete battery.

[0091] Example 7

[0092] (1) 2.5 g of 2-(trifluoromethylsulfonamido)ethyl-methacrylate and 0.5 g of maleic acid were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of azobisisobutyronitrile, 0.017 g of N,N'-methylenebisacrylamide and 20 μL of tetramethylethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L of sodium hydroxide solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after uniform stirring, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment for 30 min under ice bath and nitrogen protection, and a hydrogel was formed by radical polymerization at 40 °C for 12 h; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 10 μL of a 1 mol / L zinc trifluoromethylsulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble a complete battery.

[0093] Example 8

[0094] (1) 2.5 g of 2-(trifluoromethylsulfonamido)ethyl-methacrylate and 0.5 g of maleic acid were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of azobisisobutyronitrile, 0.017 g of N,N'-methylenebisacrylamide and 20 μL of tetramethylethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L of sodium hydroxide solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after uniform stirring, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment for 30 min under ice bath and nitrogen protection, and a hydrogel was formed by radical polymerization at 40 °C for 12 h; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 10 μL of a 1 mol / L zinc trifluoromethylsulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble a complete battery.

[0095] Example 9

[0096] (1) 2.5 g of 2-(trifluoromethylsulfonamido)ethyl-methacrylate and 0.5 g of maleic acid were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of azobisisobutyronitrile, 0.017 g of N,N'-methylenebisacrylamide and 20 μL of tetramethylethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L of sodium hydroxide solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after uniform stirring, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment for 30 min under ice bath and nitrogen protection, and a hydrogel was formed by radical polymerization at 40 °C for 12 h; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 10 μL of a 1 mol / L zinc trifluoromethylsulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble a complete battery.

[0097] Example 10

[0098] (1) 2.5 g of acrylamide and 0.5 g of fumaric acid dibutyl ester were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of sodium persulfate, 0.017 g of hydroperoxide and 20 μL of tetramethyl ethylenediamine were added, and stirred at room temperature to obtain a mixed solution; (2) a 0.1 mol / L sodium carbonate aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment under ice bath and nitrogen protection for 30 min, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 10 μL of a 1 mol / L zinc perchlorate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble into a complete battery.

[0099] Example 11

[0100] (1) 2.5 g of acrylamide and 0.5 g of fumaric acid dibutyl ester were dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of sodium persulfate, 0.017 g of hydroperoxide and 20 μL of tetramethyl ethylenediamine were added, and stirred at room temperature to obtain a mixed solution; (2) a 0.1 mol / L sodium carbonate aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment under ice bath and nitrogen protection for 30 min, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 10 μL of a 1 mol / L zinc perchlorate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble into a complete battery.

[0101] Comparative Example 1

[0102] (1) 3 g of acrylamide was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of potassium persulfate, 0.017 g of N, N'-methylene bisacrylamide and 20 μL of tetramethyl ethylenediamine were added, and stirred at room temperature to obtain a mixed solution; (2) a 0.1 mol / L ammonia solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) the bubbles in the precursor solution were removed by ultrasonic treatment under ice bath and nitrogen protection for 30 min, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 20 μL of a 1 mol / L zinc chloride aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble into a complete battery.

[0103] The stretchable in-situ immersed double-network hydrogel electrolytes prepared in Example 5 and Comparative Example 1 were used to construct Zn||Zn symmetric cells, and the current density was 1 mA / cm². 2 The following long-cycle charge-discharge test was conducted to obtain... Figure 3 The voltage-time curve shown is from... Figure 3 As can be seen from the example, the hydrogel electrolyte prepared in Example 5 can be stably cycled for 800 hours and maintain a small hysteresis voltage, while the hysteresis voltage of Comparative Example 1 increases at around 150 hours and fails at 340 hours.

[0104] The dual-network self-healing hydrogel electrolytes prepared in Example 5 and Comparative Example 1 were used to construct a full cell, and a long-term charge-discharge cycle test was conducted to obtain... Figure 4 The long-cycle performance graph is shown below. Figure 4 As can be seen from Example 5, which assembles a sodium vanadate cathode, at 1 A·g -1 It can cycle stably for 500 hours at a current density with a capacity retention of 80%, while Comparative Example 1 becomes unstable after 280 hours of cycling and eventually fails at 410 hours.

[0105] Impedance tests were performed on the iron-iron symmetric batteries composed of the dual-network self-healing hydrogel electrolytes prepared in Example 5 and Comparative Example 1. Figure 5 The diagram shows the ionic conductivity. From Figure 5 As can be seen from the preferred embodiment 5, its ionic conductivity reaches 16.77 mS·cm. -1 The ionic conductivity of Comparative Example 1 was only 3.46 mS·cm. -1 This indicates that the preferred gel electrolyte of the present invention is more conducive to improving the kinetics of aqueous zinc-ion batteries.

[0106] Comparative Example 2

[0107] (1) Dissolve 3g of acrylamide in 20mL of deionized water and stir at room temperature until transparent. Add 0.03g of sodium persulfate, 0.017g of polyisobutylene ester and 20μL of tetramethylethylenediamine and stir at room temperature to obtain a mixed solution. (2) Add 0.1mol / L sodium hydroxide aqueous solution to the mixed solution and adjust the pH to 3. Stir until homogeneous to obtain a precursor solution. (3) Remove air bubbles in the precursor solution by sonication for 30min under ice bath and nitrogen protection. Free radical polymerization is carried out at 40℃ for 12h to form a hydrogel. (4) Cut the hydrogel into 12mm diameter discs. Add 20μL of 1mol / L zinc sulfate aqueous solution to both sides of the hydrogel and sandwich it between two electrodes for in-situ immersion to obtain a hydrogel electrolyte and assemble it into a complete battery.

[0108] Comparative Example 3

[0109] (1) 3 g of N-isopropylacrylamide was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of ammonium persulfate, 0.017 g of hydroperoxide and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L potassium hydroxide aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after uniform stirring, a precursor solution was obtained; (3) under ice bath and nitrogen protection, the bubbles in the precursor solution were removed by ultrasonic for 30 min, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a circular piece with a diameter of 12 mm, 20 μL of 1 mol / L zinc trifluoromethyl sulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble into a complete battery.

[0110] Comparative Example 4

[0111] (1) 3 g of N-isopropylacrylamide was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of ammonium persulfate, 0.017 g of hydroperoxide and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L potassium hydroxide aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after uniform stirring, a precursor solution was obtained; (3) under ice bath and nitrogen protection, the bubbles in the precursor solution were removed by ultrasonic for 30 min, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a circular piece with a diameter of 12 mm, 20 μL of 1 mol / L zinc trifluoromethyl sulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble into a complete battery.

[0112] Comparative Example 5

[0113] (1) 3 g of N-isopropylacrylamide was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of ammonium persulfate, 0.017 g of hydroperoxide and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L potassium hydroxide aqueous solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after uniform stirring, a precursor solution was obtained; (3) under ice bath and nitrogen protection, the bubbles in the precursor solution were removed by ultrasonic for 30 min, and the hydrogel was formed by radical polymerization at 40°C for 12 h; (4) the hydrogel was cut into a circular piece with a diameter of 12 mm, 20 μL of 1 mol / L zinc trifluoromethyl sulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking, to obtain a hydrogel electrolyte and assemble into a complete battery.

[0114] Comparative Example 6

[0115] (1) 3 g of diacetone acrylamide was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of sodium persulfate, 0.017 g of peroxy ester and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L aqueous solution of triethylamine was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) under ice bath and nitrogen protection, ultrasonic was performed for 30 min to remove the bubbles in the precursor solution, and radical polymerization was performed at 40°C for 12 h to form a hydrogel; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 20 μL of 1 mol / L zinc chloride aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble into a complete battery.

[0116] Comparative Example 7

[0117] (1) 3 g of 2-acrylamido-2-methylpropanesulfonic acid was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of ammonium persulfate, 0.017 g of ketone peroxide and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L aqueous ammonia was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) under ice bath and nitrogen protection, ultrasonic was performed for 30 min to remove the bubbles in the precursor solution, and radical polymerization was performed at 40°C for 12 h to form a hydrogel; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 20 μL of 1 mol / L zinc sulfate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble into a complete battery.

[0118] Comparative Example 8

[0119] (1) 3 g of 2-(trifluoromethylsulfonamido)ethyl-methacrylate was dissolved in 20 mL of deionized water, stirred at room temperature until transparent, 0.03 g of ammonium persulfate, 0.017 g of hydrogen peroxide and 20 μL of tetramethyl ethylenediamine were added, and stirred uniformly at room temperature to obtain a mixed solution; (2) 0.1 mol / L aqueous potassium hydroxide solution was added dropwise into the mixed solution, the pH was adjusted to 3, and after stirring uniformly, a precursor solution was obtained; (3) under ice bath and nitrogen protection, ultrasonic was performed for 30 min to remove the bubbles in the precursor solution, and radical polymerization was performed at 40°C for 12 h to form a hydrogel; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 20 μL of 1 mol / L zinc trifluoromethylsulfonate aqueous solution was added to both sides of the hydrogel and clamped between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble into a complete battery.

[0120] Comparative Example 9

[0121] (1) 3g N-allyl-2,2,2-trifluoroacetamide was dissolved in 20 mL deionized water, stirred to dissolve at room temperature until transparent, 0.03g azobisisobutyronitrile, 0.017g dialkyl peroxide and 20 μL tetramethyl ethylenediamine were added, and the mixture was stirred uniformly at room temperature to obtain a solution; (2) a 0.1 mol / L sodium carbonate aqueous solution was added dropwise into the mixture solution, the pH was adjusted to 3, and the mixture was stirred uniformly to obtain a precursor solution; (3) the precursor solution was ultrasonically treated for 30 min under ice bath and nitrogen protection to remove the bubbles in the precursor solution, and the radical polymerization was carried out at 40°C for 12 h to form a hydrogel; (4) the hydrogel was cut into a disc with a diameter of 12 mm, 20 μL of a 1 mol / L zinc acetate aqueous solution was added dropwise on both sides of the hydrogel and sandwiched between two electrode pieces for in-situ soaking to obtain a hydrogel electrolyte and assemble a complete battery.

[0122] The comparative examples of the present application are hydrogel electrolytes of different types of amide monomer polymers, and from Table 1, it can be found that the introduction of acid anhydride monomers is beneficial to improve the physical and chemical properties of the gel electrolyte and improve its application in water-based zinc ion batteries.

[0123] Table 1 Test data of comparative examples

[0124]

[0125]

[0126] Although the present application has been described above with reference to the example embodiments and the accompanying drawings, it should be clear to those skilled in the art that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A method of making a stretchable in-situ infused double network hydrogel electrolyte, characterized in that, The method comprises: 1) preparing a uniform mixed solution of a first monomer, a second monomer, an initiator, a crosslinking agent and an accelerator; 2) adjusting the pH value of the mixed solution, and obtaining a precursor solution after stirring uniformly; 3) removing bubbles in the precursor solution, and forming a hydrogel through radical polymerization at a preset temperature; 4) cutting the hydrogel, adding a trace amount of a salt solution containing zinc ions to both sides of the cut hydrogel, and soaking the hydrogel in situ between two electrode plates to obtain a hydrogel electrolyte. The first monomer is an amide monomer, the second monomer is an anhydride monomer, and the mass ratio of the first monomer to the second monomer is 1:(0.5-10). The amide monomer includes one of acrylamide, methacrylamide, N-isopropyl acrylamide, N,N-diethyl acrylamide, isobutoxy methyl acrylamide, diacetone acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, 2-(trifluoromethylsulfonamido)ethyl-methacrylate and N-allyl-2,2,2-trifluoroacetamide. The anhydride monomer includes one of maleic anhydride, bromomaleic anhydride, dimethyl maleate, diethyl maleate, dibutyl maleate, diisooctyl maleate, cis-butenedioic acid, fumaric acid, dibutyl fumarate and bis(2-ethylhexyl) fumarate.

2. The method of making a stretchable in situ infused double network hydrogel electrolyte of claim 1, wherein, The initiator in step 1) accounts for 0.2-2% of the total mass of the first monomer and the second monomer, and the initiator includes one of potassium persulfate, sodium persulfate, ammonium persulfate and azobisisobutyronitrile.

3. The method of making a stretchable in situ infused double network hydrogel electrolyte of claim 1, wherein, The crosslinking agent in step 1) accounts for 0.01-1% of the total mass of the first monomer and the second monomer, and the crosslinking agent includes one or more of N,N'-methylenebisacrylamide, polyisobutylene acid ester, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxy ester and ketone peroxide. The accelerator in step 1) accounts for 0.5-1% of the total mass of the first monomer and the second monomer, and the accelerator includes tetramethyl ethylenediamine.

4. The method of making a stretchable in situ infused double network hydrogel electrolyte of claim 1, wherein, In step 2), an alkaline solution is used to adjust the pH value of the mixed solution, the concentration of the alkaline solution is 0.01-2 mol / L, and the alkaline solution includes one of aqueous ammonia, aqueous sodium hydroxide, aqueous potassium hydroxide, aqueous sodium carbonate, aqueous sodium bicarbonate and aqueous triethylamine.

5. The method of making a stretchable in situ infused double network hydrogel electrolyte of claim 1, wherein, In step 3), the bubbles in the precursor solution are removed by ultrasonic under ice bath and nitrogen protection, and the ultrasonic time is 0.5-2 h. The preset temperature is 30-65℃, and the polymerization time is 4-20 h.

6. The method of making a stretchable in situ infused double network hydrogel electrolyte of claim 1, wherein, In step 4), the size of the hydrogel electrolyte cut is a round piece with a diameter of 12-18 mm, the amount of the salt solution containing zinc ions added is 10-40 μL, the concentration of the salt solution containing zinc ions is 1-3 mol / L, and the salt solution containing zinc ions includes one of zinc chloride, zinc sulfate, zinc trifluoromethyl sulfonate, zinc acetate and zinc perchlorate.

7. A stretchable in situ impregnating double network hydrogel electrolyte, characterized in that, The stretchable in-situ soaked double-network hydrogel electrolyte is prepared by the method of any one of claims 1-6.

8. An aqueous zinc-ion battery, characterized in that, The aqueous zinc-ion battery includes the stretchable in-situ soaked double network hydrogel electrolyte of claim 7.

9. Use of the stretchable in-situ soaked double network hydrogel electrolyte of claim 7 in the preparation of a battery.

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