Anti-freezing and self-healing hydrogel electrolyte of aqueous zinc ion battery and preparation method of anti-freezing and self-healing hydrogel electrolyte

Abstract

The invention discloses an anti-freezing and self-healing hydrogel electrolyte of a water-based zinc ion battery and a preparation method of the anti-freezing and self-healing hydrogel electrolyte, and belongs to the technical field of water-based zinc ion batteries. The method comprises the following steps: (1) mixing a functional material, an acrylic monomer, an initiator, a cross-linking agent and soluble iron (III) salt to obtain a first product; (2) degassing the first product to remove bubbles, and then carrying out polymerization reaction to obtain a second product; and (3) soaking the second product in a 2-10 mol / L electrolyte aqueous solution for treatment to obtain the anti-freezing and self-healing hydrogel electrolyte. The hydrogel electrolyte prepared by the invention has high ionic conductivity and adhesion, and has good anti-freezing and self-healing capabilities. And when applied to the aqueous zinc ion battery, the composite material shows an ultra-long cycle life, can stably supply power even in an extremely severe environment, and has certain research significance for promoting flexible electronic equipment and large-scale energy storage application.

Description

Technical Field

[0001] The present invention relates to the technical field of aqueous zinc ion batteries, and particularly to an antifreeze and self-healing hydrogel electrolyte for an aqueous zinc ion battery and a preparation method thereof. Background Art

[0002] With the advent of the big data era, the demand for flexible electronic devices has been increasing day by day. At the same time, in order to conform to the current background of a low-carbon society, the development of environmentally friendly, safe and reliable electronic devices has become the key research direction. Since the first commercialization of lithium-ion batteries in 1990, they have successfully dominated the energy storage device market. However, when applied to flexible electronic devices, they are prone to electrolyte leakage and even fire and explosion, thus causing major safety problems. Therefore, aqueous zinc ion batteries (AZIBs) with low cost and high safety are considered to be the most promising candidates as flexible energy storage devices. However, the current AZIBs cannot be applied on a large scale because of a series of problems caused by zinc anodes. These problems include severe zinc dendrite growth and hydrogen evolution reaction during charge and discharge processes, which may lead to reduced battery life or even failure. In addition, traditional aqueous electrolytes also face the risk of leakage.

[0003] The three-dimensional network structure of the hydrogel electrolyte can retain water molecules while inhibiting the contact between free water molecules and the zinc anode, thereby alleviating the side reaction problem on the anode side. At the same time, the synthesis of hydrogel electrolytes is basically based on polymers rich in hydrophilic groups (such as amide groups, hydroxyl groups, carboxyl groups, etc.). Therefore, compared with liquid electrolytes, the abundant polar functional groups in the hydrogel electrolyte network can form ion channels that rapidly guide Zn 2+ transfer, so as to achieve uniform deposition of Zn 2+ to achieve better performance.

[0004] For example, a Chinese invention patent with the publication number CN117362523A discloses a double-network self-healing hydrogel electrolyte, its preparation method, and an aqueous zinc-ion battery. The preparation method includes: dissolving a quaternized polymer and a cross-linking agent in a zinc salt solution, ultrasonic stirring until transparent, dropping in glacial acetic acid to adjust the pH to 4-6, heating and stirring at 45-55 °C for 2-4 h to form a solution, cooling to room temperature, adding an anionic monomer and acrylamide, stirring evenly, adding an initiator under ice bath and nitrogen protection, stirring to dissolve and then ultrasonicating to remove bubbles, and performing free radical polymerization at 55-65 °C for 1-4 h to form a gel. This hydrogel electrolyte has good tensile properties, electrical conductivity, and self-healing ability. However, due to the presence of a large amount of free water in traditional electrolytes, it is prone to freezing in a low-temperature environment, restricting ion transport and causing a decline in its electrochemical performance. Especially for hydrogel electrolytes, freezing will also lead to a decline in their mechanical properties. The battery assembled by this invention still has the technical problem of being unable to operate stably at low temperatures.

[0005] A Chinese invention patent with the publication number CN117133554A provides a low-temperature antifreeze double-network hydrogel electrolyte, its preparation method, and application. The preparation method includes: mixing an aqueous ZnSO4 solution, a 2-acrylamido-2-methylpropanesulfonic acid sodium solution, and xanthan gum to obtain a first mixed solution; adding an initiator and a cross-linking agent to the first mixed solution to obtain a second mixed solution; discharging the oxygen in the second mixed solution, and performing a polymerization reaction at a preset temperature for a preset time to obtain a low-temperature antifreeze double-network hydrogel electrolyte. This solution uses polymers to solve the problem of zinc dendrites on the zinc negative electrode, and uses ZnSO4 and xanthan gum to synergistically improve the low-temperature antifreeze performance of the electrolyte. However, the assembled zinc symmetric battery can only operate stably for 1500 h at low temperatures, indicating that its ability to inhibit the growth of zinc dendrites and the generation of side reactions is still weak. In addition, this hydrogel electrolyte does not have self-healing ability and is prone to losing stress-strain performance when subjected to external impact, resulting in battery failure.

[0006] In summary, it is of great significance to prepare a hydrogel electrolyte that can resist freezing and self-heal. Based on this, providing a simple new method for preparing an antifreeze and self-healing hydrogel electrolyte and developing a hydrogel electrolyte with both high electrochemical performance and good mechanical properties are of great significance for the development of flexible zinc-ion batteries. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, in the first aspect of the present invention, there is provided a preparation method for an antifreeze and self-healing hydrogel electrolyte with simple steps and easy for large-scale production, including the following steps: (1) Mixing a functional material, an acrylic monomer, an initiator, a cross-linking agent, and a soluble iron(III) salt to obtain a first product; (2) The first product is degassed to remove bubbles and then subjected to a polymerization reaction to obtain a second product; (3) The second product is immersed in an electrolyte aqueous solution with a concentration of 2 - 10 mol / L for treatment to obtain an antifreeze and self-healing hydrogel electrolyte.

[0008] Preferably, in the step (1), the functional material includes at least one of chitosan, cellulose, carboxymethyl cellulose, gelatin, polyethylene glycol, hyaluronic acid, chitin, and sodium alginate.

[0009] Preferably, in the step (1), the initiator includes one of ammonium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, diisopropyl peroxydicarbonate, and potassium persulfate.

[0010] Based on the mechanism of free radical polymerization, those skilled in the art can select a suitable type of initiator according to actual conditions.

[0011] Preferably, in the step (1), the crosslinking agent includes one of hexyl orthosilicate, dicumyl peroxide, maleic anhydride, N,N'-methylenebisacrylamide, and ethylenediamine.

[0012] Preferably, in the step (1), the soluble iron(III) salt includes one of ferric chloride, ferric nitrate, and ferric sulfate.

[0013] Preferably, in the step (1), the mass ratio of the functional material to acrylic acid is 0.02 - 0.1:1; the mass ratio of the initiator to acrylic acid is 0.05 - 0.15:1; the mass ratio of the crosslinking agent to acrylic acid is 0.005 - 0.01:1; the mass ratio of the soluble iron(III) salt to acrylic acid is 0.01 - 0.05:1.

[0014] Excessive functional material, crosslinking agent, and soluble iron(III) salt (too low electrolyte concentration) will lead to an increase in the strength of the hydrogel electrolyte, and the self-healing effect and ionic conductivity will deteriorate; too little functional material, crosslinking agent, and soluble iron(III) salt (too high electrolyte concentration) will lead to a decrease in the strength of the hydrogel electrolyte, making it brittle and difficult to perform normal battery assembly. Therefore, for the purpose of optimizing the application effect, the proportions of each raw material should be appropriately controlled within a suitable range.

[0015] Preferably, in the step (2), the temperature of the polymerization reaction is 55 - 65 °C, and the reaction time is 2 - 6 h.

[0016] Preferably, in the step (3), the types of electrolytes in the electrolyte aqueous solution include at least one of ZnCl2, Zn(Ac)2, Zn(BF4)2, KAc, ZnSO4, MnSO4, MnCl2, and LiCl.

[0017] Preferably, in the step (3), the treatment time is 24 to 72 h.

[0018] In the second aspect of the present invention, an antifreeze and self-healing hydrogel electrolyte is provided, which is prepared by the preparation method provided in the first aspect of the present invention.

[0019] In the third aspect of the present invention, an aqueous zinc-ion battery is provided, which includes the antifreeze and self-healing hydrogel electrolyte of the second aspect of the present invention.

[0020] Preferably, the aqueous zinc-ion battery includes a zinc sheet negative electrode, an antifreeze and self-healing hydrogel electrolyte, and a carbon cloth positive electrode of polyaniline.

[0021] Preferably, the aqueous zinc-ion battery is a wearable flexible aqueous zinc-ion battery.

[0022] Based on the above technical solutions, the design concept and principle of the present invention are as follows: In the present invention, Fe 3+ coordinates with carboxyl groups to introduce dynamic metal coordination bonds into the hydrogel electrolyte, so that the hydrogel electrolyte has good self-healing effect and can also improve the mechanical properties of the hydrogel electrolyte. The addition of a high-concentration electrolyte endows it with antifreeze performance and high ionic conductivity. Since too low an electrolyte concentration will lead to an increase in the strength of the hydrogel electrolyte after soaking, resulting in a decrease in ionic conductivity and self-healing ability; too high an electrolyte concentration will lead to a decrease in the strength of the hydrogel electrolyte after soaking, making it fragile and unable to carry out normal battery assembly. Therefore, only by adopting the appropriate concentration design of the present invention can the hydrogel electrolyte obtained after soaking balance the relationship between various properties. The strong hydrogen bond ability of the carboxyl groups on the polymer surface enables the formation of a three-dimensional conductive porous network during the hydrogel polymerization process, realizing a fast migration channel for zinc ions. Therefore, the solvation structure of zinc ions can be destroyed, thereby inhibiting the growth of zinc dendrites and the occurrence of side reactions, and improving the cycle stability of AZIBs. The antifreeze and self-healing abilities and good mechanical properties of the hydrogel electrolyte enable it to stably supply power in extremely harsh environments when applied to flexible aqueous zinc-ion batteries.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention provides a preparation method for an antifreeze and self-healing hydrogel electrolyte. The hydrogel is prepared by simple radical polymerization and then immersed in a high-concentration electrolyte to obtain the target product, which has the advantages of simple steps, easy large-scale production, and being conducive to industrialization.

[0024] The present invention provides an antifreeze and self-healing hydrogel electrolyte, which has excellent antifreeze performance, self-healing performance and cycling stability, so that when it is applied to a flexible aqueous zinc-ion battery, mechanical fracture and failure at low temperature basically do not occur; specifically, the Zn||Zn symmetric battery exhibits an ultra-long cycling stable voltage of 4600 h at -20 °C, and the full battery can still maintain 88% of its capacity after 1000 cycles at -30 °C and a current density of 2 A / g.

[0025] The present invention provides an aqueous zinc-ion battery, which is made of an antifreeze and self-healing hydrogel electrolyte and can still supply power stably even under harsh conditions such as bending, folding and low temperature, and has broad application prospects. Brief Description of the Drawings

[0026] Figure 1 is a schematic flow chart of a preparation method of an antifreeze and self-healing hydrogel electrolyte provided by the present invention; Figure 2 is the tensile curve of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention and Comparative Examples 2 and 3; Figure 3 is the tensile curve of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention before and after self-healing; Figure 4 is a picture of the antifreeze and self-healing electrolyte provided in Example 1 of the present invention cut in half, half of which is stained with Coomassie Brilliant Blue G250 and then self-healed at room temperature for 1 d; Figure 5 is the ionic conductivity curve of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention at different temperatures; Figure 6 is a picture of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention after 1 d at -50 °C; Figure 7 is the voltage-time curve of the Zn||Zn symmetric battery composed of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention and Comparative Example 1 as the electrolyte at -20 °C and 0.5 mA / cm 2 below; Figure 8 is the scanning electron microscope (SEM) image of the zinc sheet after 100 cycles at -20 °C and 0.5 mA / cm 2 below with Comparative Example 1 (left) and the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention (right) as the electrolyte of the Zn||Zn symmetric battery; Figure 9It is the long - cycle performance graph of the full battery composed of the antifreeze and self - healing hydrogel electrolyte provided in Example 1 of the present invention and the electrolyte in Comparative Example 1; Figure 10 It is the power supply graph of the flexible aqueous zinc - ion battery composed of the antifreeze and self - healing hydrogel electrolyte provided in Example 1 of the present invention as the electrolyte, which is stable under different harsh conditions. Detailed implementation manners

[0027] The present invention will be further illustrated by the following examples, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions noted in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0028] Example 1 A preparation method of an antifreeze and self - healing hydrogel electrolyte is as Figure 1 shown, and the steps are as follows: (1) Mix 20 g of 1 wt.% cellulose nanofibers, 5 g of acrylic acid, 0.05 g of ammonium persulfate, 0.03 g of N,N’ - methylenebisacrylamide and 0.1 g of ferric chloride evenly to obtain a first product; (2) Then, the first product is evacuated to remove the bubbles in the mixed solution, and free - radical polymerization is carried out at 60 °C for 4 h to form a gel, obtaining a second product; (3) Immerse the second product in an aqueous mixed electrolyte solution containing 1 mol / L Zn(Ac)2 and 8 mol / L KAc for 24 h to obtain the antifreeze and self - healing hydrogel electrolyte.

[0029] Example 2 A preparation method of an antifreeze and self - healing hydrogel electrolyte, the steps are as follows: (1) Mix 10 g of 1 wt.% chitosan, 5 g of acrylic acid, 0.05 g of potassium persulfate, 0.03 g of N,N’ - methylenebisacrylamide and 0.1 g of ferric nitrate evenly to obtain a first product; (2) Then, the first product is evacuated to remove the bubbles in the mixed solution, and free - radical polymerization is carried out at 60 °C for 4 h to form a gel, obtaining a second product; (3) Immerse the second product in an aqueous mixed electrolyte solution containing 1 mol / L Zn(Ac)2 and 8 mol / L KAc for 36 h to obtain the antifreeze and self - healing hydrogel electrolyte.

[0030] Example 3 A preparation method of an antifreeze and self - healing hydrogel electrolyte, the steps are as follows: (1) Mix 10 g of 1 wt.% gelatin, 4 g of acrylic acid, 0.06 g of ammonium persulfate, 0.03 g of N,N'-methylenebisacrylamide, and 0.2 g of iron nitrate uniformly to obtain a first product; (2) Subsequently, evacuate the first product to remove the bubbles in the mixed solution, and carry out free radical polymerization at 60 °C for 4 h to form a gel, obtaining a second product; (3) Immerse the second product in an aqueous solution of a mixed electrolyte containing 1 mol / L Zn(Ac)2 and 8 mol / L KAc for 36 h to obtain an antifreeze and self-healing hydrogel electrolyte.

[0031] Example 4 A preparation method of an antifreeze and self-healing hydrogel electrolyte is as follows: (1) Mix 5 g of polyethylene glycol, 3 g of acrylic acid, 0.04 g of ammonium persulfate, 0.02 g of N,N'-methylenebisacrylamide, and 0.1 g of iron sulfate uniformly to obtain a first product; (2) Subsequently, evacuate the first product to remove the bubbles in the mixed solution, and carry out free radical polymerization at 60 °C for 4 h to form a gel, obtaining a second product; (3) Immerse the second product in an aqueous solution of 10 mol / L ZnCl2 electrolyte for 24 h to obtain an antifreeze and self-healing hydrogel electrolyte.

[0032] Example 5 A preparation method of an antifreeze and self-healing hydrogel electrolyte is as follows: (1) Mix 10 g of 1 wt.% sodium alginate, 4 g of acrylic acid, 0.05 g of potassium persulfate, 0.03 g of N,N'-methylenebisacrylamide, and 0.1 g of iron sulfate uniformly to obtain a first product; (2) Subsequently, evacuate the first product to remove the bubbles in the mixed solution, and carry out free radical polymerization at 60 °C for 4 h to form a gel, obtaining a second product; (3) Immerse the second product in an aqueous solution of 6 mol / L Zn(BF4)2 electrolyte for 36 h to obtain an antifreeze and self-healing hydrogel electrolyte.

[0033] Comparative Example 1 This comparative example provides a high-concentration electrolyte, which is prepared according to an aqueous solution of a mixed electrolyte containing 1 mol / L Zn(Ac)2 and 8 mol / L KAc.

[0034] Comparative Example 2 This comparative example provides a polyacrylic acid hydrogel electrolyte, and its preparation steps are as follows: Mix 5 g of acrylic acid, 0.05 g of ammonium persulfate, and 0.03 g of N,N'-methylenebisacrylamide evenly. Then, evacuate to remove the bubbles in the mixed solution. Polymerize at 60 °C for 4 h to form a gel by free radical polymerization. Then, immerse the polymerized hydrogel in an aqueous mixed electrolyte solution containing 1 mol / L Zn(Ac)2 and 8 mol / L KAc for 24 h to obtain a polyacrylic acid hydrogel electrolyte.

[0035] Comparative Example 3 This comparative example provides a polyacrylic acid hydrogel electrolyte containing a functional material, and its preparation steps are as follows: Mix 20 g of 1 wt.% cellulose nanofibers, 5 g of acrylic acid, 0.05 g of ammonium persulfate, and 0.03 g of N,N'-methylenebisacrylamide evenly. Then, evacuate to remove the bubbles in the mixed solution. Polymerize at 60 °C for 4 h to form a gel by free radical polymerization. Then, immerse the polymerized hydrogel in an aqueous mixed electrolyte solution containing 1 mol / L Zn(Ac)2 and 8 mol / L KAc for 24 h to obtain a polyacrylic acid hydrogel electrolyte containing a functional material.

[0036] Test the performance and electrochemical performance of the prepared hydrogel electrolytes above by the following method: (1) Conductivity test: Clamp the hydrogel electrolyte between two stainless steel sheets, and then measure the resistance by electrochemical impedance spectroscopy (EIS) of an electrochemical workstation. Calculate the conductivity using the following formula: σ = l / RA; In the formula, l is the thickness of the hydrogel electrolyte, R is the volume resistance value measured by EIS, and A is the area of the hydrogel electrolyte.

[0037] The test results of the conductivity are shown in Table 1.

[0038] Table 1: Test results of conductivity

[0039] As can be seen from Table 1, the conductivities of Examples 1 - 5 are 32 mS / cm, 25 mS / cm, 27 mS / cm, 29 mS / cm, and 21 mS / cm respectively, indicating that high-speed ion transport channels are formed inside the polymer, and at the same time, the high-concentration electrolyte also helps ion conduction. The ionic conductivity calculated from the volume resistance obtained by EIS test can reach up to 32 mS / cm, which is significantly higher than the level of 22.43 mS / cm in the prior art (CN116574274A).

[0040] (2)Tensile property test: At room temperature, rectangular hydrogel electrolyte samples were tested on a TMC-100KN universal testing machine. The actual measured length of the sample was 40 mm, the thickness was 1 mm, the width was 8 mm, and the tensile rate was 30 mm / min.

[0041] The tensile curves of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 and Comparative Examples 2 and 3 are as Figure 2 shown. It can be seen from Figure 2 that the functional materials and Fe introduced in the examples 3+ are helpful for improving the mechanical properties.

[0042] (3)Hydrogel electrolyte healing test (naked eye observation): The prepared hydrogel was cut in half, and one half was stained with Coomassie Brilliant Blue G250. Subsequently, the two hydrogel electrolytes were brought into contact with each other and left standing at room temperature for 1 d. A heavy object was hung on the lower hydrogel, and it could be observed that the hydrogel electrolyte did not break.

[0043] The tensile curves of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 before and after self-healing are as Figure 3 shown; after being cut in half and one half being stained with Coomassie Brilliant Blue G250, the picture after self-healing at room temperature for 1 d is as Figure 4 shown. It can be seen from Figure 3 and Figure 4 that the antifreeze and self-healing hydrogel electrolyte of the present invention has good self-healing ability.

[0044] In addition, Figure 5 is the ionic conductivity curve of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 of the present invention at different temperatures; Figure 6 is the picture after 1 d at -50 °C environment. It can be seen from Figure 5 and Figure 6 that the antifreeze and self-healing hydrogel electrolyte has excellent antifreeze performance, because the high-concentration electrolyte can break the hydrogen bonds between water molecules and thus lower the freezing point.

[0045] (4)Zinc symmetric battery cycling performance test: The prepared antifreeze and self-healing hydrogel electrolyte was cut into appropriate sizes and installed in a button cell, and the zinc symmetric cycling performance test was carried out in an environment of -20 °C.

[0046] The Zn||Zn symmetric battery consists of a negative zinc plate, a positive zinc plate, and an electrolyte. The aqueous zinc-ion full battery consists of a positive electrode material (carbon cloth of polyaniline), a negative electrode material (zinc plate), and an electrolyte. The electrolyte of the comparative example is 1 mol / L zinc acetate and 9 mol / L potassium acetate electrolyte, and Example 1 is the prepared hydrogel electrolyte; button batteries are assembled.

[0047] Figure 7 The anti-freezing and self-healing hydrogel electrolyte provided in Example 1 of the present invention and Comparative Example 1 as the electrolyte constitute a Zn||Zn symmetric battery, at -20 °C and 0.5 mA / cm 2 The voltage-time curve under. Figure 8 It is the SEM image of the zinc plate after 100 cycles at -20 °C and 0.5 mA / cm 2 when Comparative Example 1 (left) and the anti-freezing and self-healing hydrogel electrolyte provided in Example 1 (right) are used as the electrolyte of the Zn||Zn symmetric battery.

[0048] It can be seen from Figure 7 that in the Zn||Zn symmetric battery, in the comparative example, at -20 °C and 0.5 mA / cm 2 current density, it can only stably cycle for about 500 h, far lower than 4600 h of Example 1, indicating that Example 1 can effectively inhibit the growth of zinc dendrites and the occurrence of side reactions, thus having better cycle stability. Figure 8 The SEM comparison of the zinc plates also confirms this point.

[0049] (5) Full battery performance test: Using polyaniline as the positive electrode material, zinc plate as the negative electrode material, and the prepared anti-freezing and self-healing hydrogel electrolyte as both the electrolyte and separator, the full battery is assembled and its electrochemical performance is tested at -30 °C and 2 A / g. The test results are shown in Table 2.

[0050] Table 2: Test results of full battery performance

[0051] In Table 2, the capacity retention rates of each example are significantly better than those of the comparative example.

[0052] Figure 9 It is the long cycle performance graph of the full battery composed of the anti-freezing and self-healing hydrogel electrolyte provided in Example 1 and Comparative Example 1 as the electrolyte. It can be seen from Figure 9 that in the full battery, in the comparative example, at -30 °C and 2 A / g, after 1000 cycles, the capacity can only be maintained at 25%, far lower than 88% in Example 1.

[0053] Figure 10It is a power supply diagram showing the stability of the antifreeze and self-healing hydrogel electrolyte provided in Example 1 as the electrolyte for a flexible aqueous zinc-ion battery under different harsh conditions. From Figure 10 it can be seen that the fabricated flexible aqueous zinc-ion battery can light up normally under their respective harsh conditions (bending, folding, low temperature), indicating that it can supply power stably.

[0054] The above test results show that the hydrogel electrolyte prepared by the present invention has high ionic conductivity and adhesiveness, and has good antifreeze and self-healing capabilities. When applied to aqueous zinc-ion batteries, it exhibits an ultra-long cycle life and can supply power stably even under extremely harsh environments, which has certain research significance for promoting flexible electronic devices and large-scale energy storage applications.

[0055] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. A preparation method of an antifreeze and self-healing hydrogel electrolyte, characterized in that, It includes the following steps: (1) Mix a functional material, an acrylic monomer, an initiator, a crosslinking agent, and a soluble iron(III) salt to obtain a first product; (2) Degas the first product to remove air bubbles, and then carry out a polymerization reaction to obtain a second product; (3) Immerse the second product in an electrolyte aqueous solution with a concentration of 2 - 10 mol / L for treatment to obtain an antifreeze and self-healing hydrogel electrolyte.

2. The preparation method of the antifreeze and self-healing hydrogel electrolyte according to claim 1, characterized in that: In the step (1), the functional material includes at least one of chitosan, cellulose, carboxymethyl cellulose, gelatin, polyethylene glycol, hyaluronic acid, chitin, and sodium alginate; the initiator includes one of ammonium persulfate, azobisisobutyronitrile, azobisisoheptonitrile, diisopropyl peroxydicarbonate, and potassium persulfate; the crosslinking agent includes one of hexyl orthosilicate, dicumyl peroxide, maleic anhydride, N,N'-methylenebisacrylamide, and ethylenediamine; the soluble iron(III) salt includes one of ferric chloride, ferric nitrate, and ferric sulfate.

3. The preparation method of the antifreeze and self-healing hydrogel electrolyte according to claim 1, wherein: In the step (1), the mass ratio of the functional material to acrylic acid is 0.02 - 0.1:1; the mass ratio of the initiator to acrylic acid is 0.05 - 0.15:1; the mass ratio of the crosslinking agent to acrylic acid is 0.005 - 0.01:1; the mass ratio of the soluble iron(III) salt to acrylic acid is 0.01 - 0.05:

1.

4. The preparation method of the antifreeze and self-healing hydrogel electrolyte according to claim 1, characterized in that: In the step (2), the temperature of the polymerization reaction is 55 - 65 °C, and the reaction time is 2 - 6 h.

5. The preparation method of the antifreeze and self-healing hydrogel electrolyte according to claim 1, characterized in that: In the step (3), the types of electrolytes in the electrolyte aqueous solution include at least one of ZnCl2, Zn(Ac)2, Zn(BF4)2, KAc, ZnSO4, MnSO4, MnCl2, and LiCl.

6. The preparation method of the antifreeze and self-healing hydrogel electrolyte according to claim 1, wherein: In the step (3), the treatment time is 24 - 72 h.

7. An antifreeze and self-healing hydrogel electrolyte, characterized in that: It is prepared by using the preparation method according to any one of claims 1 - 6.

8. An aqueous zinc ion battery, characterized in that: It includes the antifreeze and self-healing hydrogel electrolyte according to claim 7.

9. The aqueous zinc-ion battery according to claim 8, wherein: The aqueous zinc-ion battery includes a zinc sheet negative electrode, an antifreeze and self-healing hydrogel electrolyte, and a carbon cloth positive electrode of polyaniline.

10. The aqueous zinc ion battery according to claim 8, wherein: The aqueous zinc-ion battery is a wearable flexible aqueous zinc-ion battery.

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