Hydrogel electrolyte, preparation method thereof and zinc ion battery

Abstract

The invention relates to the technical field of zinc ion battery electrolyte preparation, and discloses a hydrogel electrolyte, a preparation method thereof and a zinc ion battery, and the preparation method comprises the following steps: providing a thickening agent, and adding the thickening agent into water to obtain a thickening solution; providing a zinc salt, a manganese salt, acrylamide, a cross-linking agent and a sulfo group-containing polymerizable monomer, and adding into the thickening solution to obtain a cross-linked solution; providing an initiator, and adding the initiator into water to obtain an initiating solution; and adding the initiating solution into the cross-linking solution, and carrying out polymerization reaction to obtain the hydrogel electrolyte. The sulfonic acid group has excellent affinity to zinc ions and water molecules, so that the zinc ions can be uniformly deposited on the surface of a negative electrode in the charging and discharging process, the formation of zinc dendrites is inhibited, the battery efficiency and safety performance of a subsequent zinc ion battery finished product are improved, the content of free water in a hydrogel electrolyte system is reduced, and the service life of the hydrogel electrolyte system is prolonged. Side reactions caused by free water are reduced, and the cycle stability and safety of a subsequent zinc ion battery finished product are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of zinc-ion battery electrolytes, and particularly relates to a hydrogel electrolyte, a preparation method thereof, and a zinc-ion battery. Background Art

[0002] Batteries are commonly used energy storage carriers in people's daily lives. In the current energy storage field, zinc-ion batteries have attracted increasing attention due to their high safety, low cost, and environmental friendliness. They are suitable for large-scale industrial production and more in line with the development concept of environmental protection. Therefore, zinc-ion batteries are important candidates for large-scale energy storage and power sources for portable electronic devices, and are one of the most promising energy storage devices. Hydrogel electrolytes are important components in zinc-ion batteries, providing channels for the dissolution and migration of zinc ions during the charge and discharge processes of zinc-ion batteries, and are essential components of zinc-ion batteries. The performance of hydrogel electrolytes also affects the overall performance of zinc-ion batteries.

[0003] However, in existing zinc-ion batteries, zinc dendrite phenomena are prone to occur during the charge and discharge processes, resulting in local short circuits inside the battery, affecting the battery efficiency and safety performance. At the same time, free water in the electrolytes of zinc-ion batteries is prone to side reactions, such as hydrogen evolution reactions and zinc ion hydrolysis reactions, and the cycle stability of zinc-ion batteries is poor. Therefore, improving the formation of zinc dendrites and the side reaction problems of free water in hydrogel electrolytes is the current research focus and difficulty of hydrogel electrolytes. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a preparation method of a hydrogel electrolyte and a zinc-ion battery that can effectively solve the problems of zinc dendrites and free water side reactions in hydrogel electrolytes, significantly improve their safety performance and cycle stability, and the prepared hydrogel electrolyte has stable performance, good cycle performance, good safety, and long life.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A preparation method of a hydrogel electrolyte includes the following steps:

[0007] Provide a thickening agent, add the thickening agent to water, and stir evenly to obtain a thickening solution;

[0008] Provide a zinc salt, a manganese salt, acrylamide, a crosslinking agent, and a polymerizable monomer containing a sulfonic acid group, add the zinc salt, the manganese salt, the acrylamide, the crosslinking agent, and the polymerizable monomer containing a sulfonic acid group to the thickening solution, and stir evenly to obtain a crosslinking solution;

[0009] Provide an initiator, add the initiator to water, and stir evenly to obtain an initiation solution;

[0010] Add the initiator solution to the crosslinking solution. After stirring evenly, pour it into a mold for polymerization reaction to obtain a hydrogel electrolyte.

[0011] In one embodiment, before the operation of adding the initiator solution to the crosslinking solution, a catalyst is further provided. The catalyst is added to water and stirred evenly to obtain a catalytic solution, and the catalytic solution is added to the crosslinking solution.

[0012] In one embodiment, before the operation of adding the initiator solution to the crosslinking solution, anhydrous copper sulfate is further provided. The anhydrous copper sulfate is added to water and stirred evenly to obtain an anhydrous copper sulfate solution, and the anhydrous copper sulfate solution is added to the crosslinking solution.

[0013] In one embodiment, the catalyst is tannic acid.

[0014] In one embodiment, the thickener is sodium carboxymethyl cellulose.

[0015] In one embodiment, the sulfonic acid group-containing polymerizable monomer is at least one of methacryloylethyl sulfobetaine, vinyl sulfonic acid, styrene sulfonic acid, methacrylic acid sulfonic acid, isoprene sulfonic acid, 2-hydroxy-3-allyl propanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylamide butyl sulfonic acid, acryloyloxybutyl sulfonic acid, 1-allyloxy-2-hydroxy sulfonic acid, sodium allyl sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, vinyl sulfonic acid, and 2-methyl-acryloyloxypropyl sulfonic acid.

[0016] In one embodiment, in the operation of pouring into a mold for polymerization reaction, the polymerization temperature is controlled at 25°C to 35°C, and the polymerization time is 20 min to 50 min.

[0017] In one embodiment, in the operation of adding the thickener to water and stirring evenly, the thickener is divided into at least two portions, and each portion of the thickener is added to water at intervals, and the stirring time is controlled at 2 h to 3 h.

[0018] A hydrogel electrolyte is made by the preparation method of the above hydrogel electrolyte.

[0019] A zinc ion battery includes a positive electrode, a negative electrode, and a hydrogel electrolyte, and the electrolyte is the hydrogel electrolyte prepared by the above preparation method.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] (1) By adding a polymerizable monomer containing a sulfonic acid group, the polymerizable monomer containing a sulfonic acid group has a sulfonic acid group, and the sulfonic acid groups are uniformly dispersed in the hydrogel electrolyte system. The sulfonic acid groups have excellent affinity for zinc ions. When the hydrogel electrolyte is encapsulated with the positive electrode and the negative electrode to form a zinc ion battery, the sulfonic acid groups uniformly dispersed in the hydrogel electrolyte system can generate a guiding force on the zinc ions, enabling the zinc ions to be uniformly deposited on the surface of the negative electrode during charge and discharge, realizing a uniform and orderly deposition behavior of zinc ions, avoiding the phenomenon of non-uniform deposition of zinc ions on the surface of the negative electrode, thereby effectively inhibiting the formation of zinc dendrites, which is beneficial to improving the battery efficiency and safety performance of the subsequent zinc ion battery products. At the same time, the sulfonic acid groups also have good affinity with water molecules and can form an interaction force with water molecules, which is beneficial to effectively locking the free water in the hydrogel electrolyte system, reducing the content of free water in the hydrogel electrolyte system, thereby greatly reducing the side reactions caused by free water, avoiding the consumption of active substances and energy in the hydrogel electrolyte system, and further enhancing the cycle stability and safety of the subsequent zinc ion battery products.

[0022] (2) By adding a thickening agent, the thickening agent is sodium carboxymethyl cellulose. The zinc salt, manganese salt, acrylamide, crosslinking agent and the polymerizable monomer containing a sulfonic acid group are added to the thickening solution system that has been stirred evenly. The molecular chains of sodium carboxymethyl cellulose intersect with each other to form a network structure, which can increase the viscosity in the solution and make components such as the zinc salt, manganese salt, acrylamide, crosslinking agent and the polymerizable monomer containing a sulfonic acid group be uniformly and stably dispersed in the system, which is beneficial to ensuring the uniformity and stability of each component in the subsequent prepared hydrogel electrolyte system, thereby further improving the stability of the prepared hydrogel electrolyte product. And the polymerizable monomer containing a sulfonic acid group is uniformly dispersed in the hydrogel electrolyte system, which can more uniformly generate a guiding force on zinc ions and water molecules, ensuring that zinc ions can be uniformly deposited on the surface of the negative electrode during charge and discharge, ensuring a uniform and orderly deposition behavior of zinc ions, and ensuring a comprehensive attraction and locking of water molecules in the system, reducing side reactions caused by free water, thereby further improving the battery cycle efficiency and safety performance of the prepared zinc ion battery products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a flowchart of the steps of the preparation method of the hydrogel electrolyte according to an embodiment of the present invention;

[0025] Figure 2 It is a comparative graph of impedance (EIS) test for zinc-ion batteries assembled with the hydrogel electrolytes of Example 2 and Comparative Examples 1 and 2 of the present invention;

[0026] Figure 3 It is a comparative graph of cyclic voltammetry (CV) curve test for zinc-ion batteries assembled with the hydrogel electrolytes of Example 2 and Comparative Examples 1 and 2 of the present invention. Detailed implementation manners

[0027] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present invention can be understood more thoroughly and comprehensively.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term “and / or” used herein includes any and all combinations of one or more of the related listed items.

[0029] In one embodiment, please refer to Figure 1 , a preparation method of a hydrogel electrolyte, comprising the following steps:

[0030] S110. Provide a thickener, add the thickener to water, and stir evenly to obtain a thickening solution.

[0031] It should be noted that by providing a thickener and adding the thickener to water, specifically, deionized water is used for water to avoid introducing impurity ions into the thickening solution obtained by stirring. The thickening solution prepared makes the thickener evenly dispersed in the solution system, which is beneficial to more uniformly and quickly mixing with each component subsequently, achieving a better effect of adjusting the viscosity of the solution system.

[0032] S120. Provide a zinc salt, a manganese salt, acrylamide, a crosslinking agent, and a polymerizable monomer containing a sulfonic acid group, add the zinc salt, the manganese salt, the acrylamide, the crosslinking agent, and the polymerizable monomer containing a sulfonic acid group to the thickening solution, and stir evenly to obtain a crosslinking solution.

[0033] It should be noted that by adding zinc salt, manganese salt, acrylamide, crosslinking agent and polymerizable monomer containing sulfonic acid group into a uniform thickening solution, the zinc salt, manganese salt, acrylamide, crosslinking agent and polymerizable monomer containing sulfonic acid group can be uniformly dispersed in the thickening solution system. The zinc salt and manganese salt, as the active components of the hydrogel electrolyte, provide zinc ions for the charge and discharge of the zinc ion battery. In this embodiment, the zinc salt is at least one of zinc sulfate heptahydrate, zinc trifluoromethanesulfonate, zinc chloride, zinc perchlorate, zinc acetate, and the manganese salt is manganese sulfate monohydrate. Zinc sulfate heptahydrate, zinc trifluoromethanesulfonate, zinc chloride, zinc perchlorate, zinc acetate and manganese sulfate monohydrate are all common zinc salts and manganese salts, and are easily soluble in the solution system, which is beneficial to quickly disperse in the solution system. Acrylamide and polymerizable monomer containing sulfonic acid group, as the polymer monomer of the hydrogel electrolyte, undergo a polymerization reaction under the action of a crosslinking agent and an initiator to polymerize into a gel-state hydrogel electrolyte. The crosslinking agent uses methylene bisacrylamide. After stirring the zinc salt, manganese salt, acrylamide, crosslinking agent and polymerizable monomer containing sulfonic acid group with the thickening solution evenly, the components can be mixed evenly before the polymerization reaction to form a uniform solution system, which is conducive to the subsequent more uniform mixing of each component with the initiator, ensuring the better and more comprehensive progress of the polymerization reaction, and is beneficial to preparing a hydrogel electrolyte product with uniform texture, so that the polymerizable monomer containing sulfonic acid group is evenly dispersed in the hydrogel electrolyte, ensuring that zinc ions can be evenly attracted during charge and discharge, so that zinc ions are evenly deposited on the negative electrode, and can ensure the uniform locking of water molecules in the system, effectively reducing side reactions caused by free water, and improving the cycle stability and safety of the subsequent zinc ion battery product.

[0034] S130. Provide an initiator, add the initiator into water, and stir evenly to obtain an initiation solution.

[0035] It should be noted that by adding the initiator into water, in this embodiment, the initiator uses ammonium persulfate and the water uses deionized water to avoid introducing impurity ions. After stirring evenly, an initiation solution is obtained, which is beneficial to the uniform dispersion of the initiator in the solution system, and is beneficial to the subsequent more uniform and rapid mixing with each component to ensure the normal progress of the polymerization reaction.

[0036] S140. Add the initiation solution into the crosslinking solution, stir evenly, and then pour it into a mold for polymerization reaction to obtain a hydrogel electrolyte.

[0037] It should be noted that the separately and evenly stirred initiating solution and cross-linking solution are mixed and then stirred. After stirring evenly, it is poured into a mold. The mold can be designed according to the shape of the hydrogel electrolyte required by production design. It is left standing at room temperature for a polymerization reaction to obtain a gel-like hydrogel electrolyte product. The preparation method of the hydrogel electrolyte is simple, suitable for industrial production. By adding a polymerizable monomer containing a sulfonic group, the polymerizable monomer containing a sulfonic group has a sulfonic acid group, and the sulfonic acid groups are evenly dispersed in the hydrogel electrolyte system. The sulfonic acid groups have excellent affinity for zinc ions. When the hydrogel electrolyte is encapsulated with the positive electrode and the negative electrode to form a zinc-ion battery, the sulfonic acid groups evenly dispersed in the hydrogel electrolyte system can generate a guiding force on zinc ions, enabling zinc ions to be evenly deposited on the surface of the negative electrode during charge and discharge, realizing a uniform and orderly deposition behavior of zinc ions, avoiding the phenomenon of uneven deposition of zinc ions on the surface of the negative electrode, thereby effectively inhibiting the formation of zinc dendrites, which is beneficial to improving the battery efficiency and safety performance of the subsequent zinc-ion battery product.

[0038] Furthermore, the sulfonic acid groups also have good affinity with water molecules and can form an interaction force with water molecules, which is beneficial to effectively locking the free water in the hydrogel electrolyte system, reducing the free water content in the hydrogel electrolyte system, thereby greatly reducing the side reactions caused by free water, avoiding the consumption of active substances and energy in the hydrogel electrolyte system, and further enhancing the cycle stability and safety of the subsequent zinc-ion battery product.

[0039] In one implementation, before the operation of adding the initiating solution to the cross-linking solution, a catalyst is also provided. The catalyst is added to water and stirred evenly to obtain a catalytic solution, and the catalytic solution is added to the cross-linking solution. It can be understood that by adding a catalyst, the catalyst is a catalyst with a catalytic effect on the polymerization reaction. In this embodiment, the catalyst is tannic acid. By adding tannic acid as the catalyst for the polymerization of the hydrogel electrolyte, it can accelerate the polymerization of monomers at room temperature, which is beneficial to improving the polymerization efficiency, and can carry out rapid polymerization at room temperature, reducing the energy input, which is beneficial to improving the overall production efficiency of the hydrogel electrolyte and reducing the production cost.

[0040] In one of the embodiments, before the operation of adding the initiation solution to the crosslinking solution, anhydrous copper sulfate is further provided. The anhydrous copper sulfate is added to water and stirred evenly to obtain an anhydrous copper sulfate solution, and the anhydrous copper sulfate solution is added to the crosslinking solution. It can be understood that by adding anhydrous copper sulfate, the anhydrous copper sulfate can serve as an auxiliary catalyst to enhance the catalytic effect of tannic acid. When used in combination with tannic acid, it can play a synergistic role, greatly improving the catalytic promotion of the polymerization reaction, enabling the polymerization reaction to be carried out at room temperature to obtain a hydrogel electrolyte product with high polymerization efficiency and high production efficiency, which is suitable for industrial production.

[0041] In one of the embodiments, the thickener is sodium carboxymethyl cellulose. It can be understood that when the thickener is sodium carboxymethyl cellulose, sodium carboxymethyl cellulose is an anionic polymer compound prepared by reacting natural cellulose with caustic alkali and monochloroacetic acid. It is easy to disperse in water to form a transparent colloidal solution. The molecular chains of sodium carboxymethyl cellulose in the colloidal solution system intersect with each other to form a network structure, which can increase the viscosity in the solution and enable components such as zinc salt, manganese salt, acrylamide, crosslinking agent, and polymerizable monomer containing sulfonic acid group to be evenly and stably dispersed in the system. This is beneficial to ensuring the uniformity and stability of each component in the subsequent prepared hydrogel electrolyte system, thereby further improving the stability of the prepared hydrogel electrolyte product. Moreover, the polymerizable monomer containing sulfonic acid group is evenly dispersed in the hydrogel electrolyte system, which can more evenly generate a guiding force on zinc ions and water molecules, ensuring that zinc ions can be evenly deposited on the surface of the negative electrode during charge and discharge, ensuring the uniform and orderly deposition behavior of zinc ions, and ensuring the comprehensive attraction and locking of water molecules in the system, reducing side reactions caused by free water, thereby further improving the battery cycle efficiency and safety performance of the prepared zinc ion battery product.

[0042] In one embodiment, the sulfonic acid group-containing polymerizable monomer is at least one of methacryloylethyl sulfobetaine, vinyl sulfonic acid, styrene sulfonic acid, methacrylic acid sulfonic acid, isoprene sulfonic acid, 2-hydroxy-3-allylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylamidebutylsulfonic acid, acryloxybutylsulfonic acid, 1-allyloxy-2-hydroxysulfonic acid, sodium allyl sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, vinyl sulfonic acid and 2-methyl-acryloyloxypropyl sulfonic acid. It can be understood that methacryloylethyl sulfobetaine, vinyl sulfonic acid, styrene sulfonic acid, methacrylic acid sulfonic acid, isoprene sulfonic acid, 2-hydroxy-3-allylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylamide butyl sulfonic acid, acryloxybutyl sulfonic acid, 1-allyloxy-2-hydroxysulfonic acid, sodium allyl sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, vinyl sulfonic acid and 2-methyl-acryloyloxypropyl sulfonic acid are all common sulfonic acid group-containing polymerizable monomers, have polymerizability, and can ensure the normal progress of the polymerization reaction. Each sulfonic acid group-containing polymerizable monomer can be used alone or in combination, which is not described in detail in this embodiment.

[0043] In one embodiment, in the operation of pouring into the mold for polymerization reaction, the polymerization temperature is controlled to be 25°C to 35°C, and the polymerization time is 20min to 50min. It can be understood that when the polymerization reaction is carried out, the polymerization temperature is controlled to be 25°C to 35°C, and the polymerization time is 20min to 50min, that is, the polymerization reaction is carried out at room temperature, and the polymerization reaction is carried out for 20min to 50min, so as to ensure that the polymerization reaction is fully carried out and a hydrogel electrolyte with good finished quality is prepared.

[0044] In one embodiment, in the operation of adding the thickener to water and stirring evenly, the thickener is divided into at least two portions, and each portion of the thickener is added to the water at intervals, and the stirring time is controlled to be 2h to 3h. It can be understood that by dividing the thickener into multiple portions in equal amounts, and then adding each portion of the thickener to the water intermittently for stirring, for example, adding a portion of the thickener every 1h, it is beneficial to evenly disperse the thickener in the water and avoid agglomeration. At the same time, the stirring efficiency can be accelerated to avoid the need to increase the stirring time due to the agglomeration problem after the thickener is added once. The stirring effect is good, which is beneficial to obtain a uniformly dispersed and stable thickening solution system, ensuring that the subsequent components are evenly dispersed in the thickening solution system, thereby preparing a hydrogel electrolyte product with uniform texture, which is beneficial to ensure that the sulfonic acid group-containing polymerizable monomer is evenly dispersed in the hydrogel electrolyte product, and ensure that the sulfonic acid group fully exerts its guiding effect on zinc ions and locking effect on water molecules.

[0045] In one of the embodiments, the hydrogel electrolyte comprises the following components in parts by mass: 0.08 to 0.12 parts of a thickener, 10 to 14 parts of a zinc salt, 0.6 to 0.8 parts of a manganese salt, 2 to 3 parts of acrylamide, 0.01 to 0.02 parts of a crosslinking agent, 1.3 to 1.5 parts of a polymerizable monomer containing a sulfonic group, 0.12 to 0.15 parts of an initiator, 0.1 to 0.12 parts of anhydrous copper sulfate, 0.1 to 0.3 parts of a catalyst, and 100 to 110 parts of water. It should be noted that after the components are weighed separately according to the proportions, the amounts of the components are ensured to be appropriate, and the hydrogel electrolyte is prepared according to each preparation step to ensure the stable properties and quality of the prepared hydrogel electrolyte finished product.

[0046] A hydrogel electrolyte is made by the preparation method of the above-mentioned hydrogel electrolyte.

[0047] It should be noted that the hydrogel electrolyte prepared by the above-mentioned hydrogel electrolyte preparation method introduces sulfonic acid groups. The sulfonic acid groups have excellent affinity for zinc ions and water molecules, enabling the zinc ions to be evenly deposited on the surface of the negative electrode during charge and discharge, inhibiting the formation of zinc dendrites, improving the battery efficiency and safety performance of the subsequent zinc ion battery finished product, and reducing the free water content in the hydrogel electrolyte system, reducing side reactions caused by free water, and further enhancing the cycle stability and safety of the subsequent zinc ion battery finished product.

[0048] A zinc ion battery includes a positive electrode, a negative electrode, and a hydrogel electrolyte, and the electrolyte is the hydrogel electrolyte prepared by the above-mentioned preparation method.

[0049] It should be noted that by providing a positive electrode and a negative electrode, and then assembling the positive electrode, the negative electrode, and the hydrogel electrolyte prepared by the above-mentioned preparation method to obtain a zinc ion battery, the zinc ion battery has good battery cycle performance and cycle stability, and good safety performance and a long service life.

[0050] Compared with the prior art, the present invention has at least the following advantages:

[0051] (1) By adding a polymerizable monomer containing a sulfonic acid group, the polymerizable monomer containing a sulfonic acid group has a sulfonic acid group, and the sulfonic acid groups are uniformly dispersed in the hydrogel electrolyte system. The sulfonic acid groups have excellent affinity for zinc ions. When the hydrogel electrolyte is encapsulated with the positive electrode and the negative electrode to form a zinc ion battery, the sulfonic acid groups uniformly dispersed in the hydrogel electrolyte system can generate a guiding force on the zinc ions, enabling the zinc ions to be uniformly deposited on the surface of the negative electrode during the charge and discharge process, realizing a uniform and orderly deposition behavior of zinc ions, avoiding the phenomenon of uneven deposition of zinc ions on the surface of the negative electrode, thereby effectively suppressing the formation of zinc dendrites, which is beneficial to improving the battery efficiency and safety performance of the subsequent zinc ion battery product. At the same time, the sulfonic acid groups also have good affinity with water molecules and can form an interaction force with water molecules, which is beneficial to effectively locking the free water in the hydrogel electrolyte system, reducing the content of free water in the hydrogel electrolyte system, thereby greatly reducing the side reactions caused by free water, avoiding the consumption of active substances and energy in the hydrogel electrolyte system, and further enhancing the cycle stability and safety of the subsequent zinc ion battery product.

[0052] (2) By adding a thickening agent, the thickening agent is sodium carboxymethyl cellulose. The zinc salt, manganese salt, acrylamide, crosslinking agent and the polymerizable monomer containing a sulfonic acid group are added to the thickening solution system that has been stirred evenly. The molecular chains of sodium carboxymethyl cellulose intersect with each other to form a network structure, which can increase the viscosity in the solution and make components such as the zinc salt, manganese salt, acrylamide, crosslinking agent and the polymerizable monomer containing a sulfonic acid group uniformly and stably dispersed in the system, which is beneficial to ensuring the uniformity and stability of each component in the subsequent prepared hydrogel electrolyte system, thereby further improving the stability of the prepared hydrogel electrolyte product. And the polymerizable monomer containing a sulfonic acid group is uniformly dispersed in the hydrogel electrolyte system, which can more uniformly generate a guiding force on zinc ions and water molecules, ensure that zinc ions can be uniformly deposited on the surface of the negative electrode during the charge and discharge process, ensure the uniform and orderly deposition behavior of zinc ions, and ensure the comprehensive attraction and locking of water molecules in the system, reducing the side reactions caused by free water, thereby further improving the battery cycle efficiency and safety performance of the prepared zinc ion battery product.

[0053] The following is the specific embodiment part.

[0054] Example 1

[0055] By mass, 0.08 parts of sodium carboxymethyl cellulose are provided. The sodium carboxymethyl cellulose is divided into two parts, and the two parts of the sodium carboxymethyl cellulose are added to 80 parts of water at intervals, and the stirring time is controlled to be 2 h and stirred evenly to obtain a thickening solution;

[0056] Provide 10 parts of zinc salt, 0.6 part of manganese salt, 2 parts of acrylamide, 0.01 part of methylene bisacrylamide, and 1.3 parts of polymerizable monomer containing sulfonic acid group. Add the zinc salt, the manganese salt, the acrylamide, the methylene bisacrylamide, and the polymerizable monomer containing sulfonic acid group to the thickening solution, and stir evenly to obtain a crosslinked solution;

[0057] Provide 0.12 part of ammonium persulfate. Add the ammonium persulfate to 5 parts of water and stir evenly to obtain an initiating solution;

[0058] Provide 0.1 part of anhydrous copper sulfate. Add the anhydrous copper sulfate to 5 parts of water and stir evenly to obtain an anhydrous copper sulfate solution;

[0059] Provide 0.1 part of tannic acid. Add the tannic acid to 10 parts of water and stir evenly to obtain a catalytic solution;

[0060] Add the initiating solution, the anhydrous copper sulfate solution, and the catalytic solution to the crosslinked solution. After stirring evenly, pour it into a mold for polymerization reaction. Control the polymerization temperature at 25°C and the polymerization time at 20 min to obtain the hydrogel electrolyte of Example 1.

[0061] Example 2

[0062] By mass, provide 0.1 part of sodium carboxymethyl cellulose. Divide the sodium carboxymethyl cellulose into two parts, and add the two parts of sodium carboxymethyl cellulose to 82 parts of water at intervals, control the stirring time to be 2.5 h, and stir evenly to obtain a thickening solution;

[0063] Provide 12 parts of zinc salt, 0.7 part of manganese salt, 2.5 parts of acrylamide, 0.015 part of methylene bisacrylamide, and 1.4 parts of polymerizable monomer containing sulfonic acid group. Add the zinc salt, the manganese salt, the acrylamide, the methylene bisacrylamide, and the polymerizable monomer containing sulfonic acid group to the thickening solution, and stir evenly to obtain a crosslinked solution;

[0064] Provide 0.14 part of ammonium persulfate. Add the ammonium persulfate to 6 parts of water and stir evenly to obtain an initiating solution;

[0065] Provide 0.11 part of anhydrous copper sulfate. Add the anhydrous copper sulfate to 6 parts of water and stir evenly to obtain an anhydrous copper sulfate solution;

[0066] Provide 0.2 part of tannic acid. Add the tannic acid to 11 parts of water and stir evenly to obtain a catalytic solution;

[0067] Add the initiation solution, the anhydrous copper sulfate solution and the catalytic solution to the crosslinking solution. After stirring evenly, pour it into a mold for polymerization reaction. Control the polymerization temperature at 30 °C and the polymerization time at 35 min to obtain the hydrogel electrolyte of Example 2.

[0068] Example 3

[0069] Provide 0.12 parts of sodium carboxymethylcellulose. Divide the sodium carboxymethylcellulose into two parts and add the two parts of sodium carboxymethylcellulose to 84 parts of water at intervals. Control the stirring time to be 3 h and stir evenly to obtain a thickening solution;

[0070] Provide 14 parts of zinc salt, 0.8 part of manganese salt, 3 parts of acrylamide, 0.02 part of methylene bisacrylamide and 1.5 parts of polymerizable monomer containing sulfonic group. Add the zinc salt, the manganese salt, the acrylamide, the methylene bisacrylamide and the polymerizable monomer containing sulfonic group to the thickening solution and stir evenly to obtain a crosslinking solution;

[0071] Provide 0.15 parts of ammonium persulfate. Add the ammonium persulfate to 7 parts of water and stir evenly to obtain an initiation solution;

[0072] Provide 0.12 parts of anhydrous copper sulfate. Add the anhydrous copper sulfate to 7 parts of water and stir evenly to obtain an anhydrous copper sulfate solution;

[0073] Provide 0.3 parts of tannic acid. Add the tannic acid to 12 parts of water and stir evenly to obtain a catalytic solution;

[0074] Add the initiation solution, the anhydrous copper sulfate solution and the catalytic solution to the crosslinking solution. After stirring evenly, pour it into a mold for polymerization reaction. Control the polymerization temperature at 35 °C and the polymerization time at 50 min to obtain the hydrogel electrolyte of Example 3.

[0075] Comparative Example 1

[0076] Provide 0.1 part of sodium carboxymethylcellulose. Divide the sodium carboxymethylcellulose into two parts and add the two parts of sodium carboxymethylcellulose to 82 parts of water at intervals. Control the stirring time to be 2.5 h and stir evenly to obtain a thickening solution;

[0077] Provide 12 parts of zinc salt, 0.7 part of manganese salt, 2.5 parts of acrylamide and 0.015 part of methylene bisacrylamide. Add the zinc salt, the manganese salt, the acrylamide and the methylene bisacrylamide to the thickening solution and stir evenly to obtain a crosslinking solution;

[0078] Provide 0.14 parts of ammonium persulfate. Add the ammonium persulfate to 6 parts of water and stir evenly to obtain an initiation solution;

[0079] Provide 0.11 parts of anhydrous copper sulfate, add the anhydrous copper sulfate to 6 parts of water, and stir evenly to obtain an anhydrous copper sulfate solution;

[0080] Provide 0.2 parts of tannic acid, add the tannic acid to 11 parts of water, and stir evenly to obtain a catalytic solution;

[0081] Add the initiating solution, the anhydrous copper sulfate solution and the catalytic solution to the crosslinking solution, stir evenly, then pour it into a mold for polymerization reaction, control the polymerization temperature at 30 °C, and the polymerization time at 35 min to obtain the hydrogel electrolyte of Comparative Example 1.

[0082] Comparative Example 2

[0083] By mass, provide 12 parts of zinc salt, 0.7 parts of manganese salt, 2.5 parts of acrylamide, 0.015 parts of methylene bisacrylamide and 1.4 parts of polymerizable monomer containing sulfonic group, add the zinc salt, the manganese salt, the acrylamide, the methylene bisacrylamide and the polymerizable monomer containing sulfonic group to 82 parts of water, and stir evenly to obtain a crosslinking solution;

[0084] Provide 0.14 parts of ammonium persulfate, add the ammonium persulfate to 6 parts of water, and stir evenly to obtain an initiating solution;

[0085] Provide 0.11 parts of anhydrous copper sulfate, add the anhydrous copper sulfate to 6 parts of water, and stir evenly to obtain an anhydrous copper sulfate solution;

[0086] Provide 0.2 parts of tannic acid, add the tannic acid to 11 parts of water, and stir evenly to obtain a catalytic solution;

[0087] Add the initiating solution, the anhydrous copper sulfate solution and the catalytic solution to the crosslinking solution, stir evenly, then pour it into a mold for polymerization reaction, control the polymerization temperature at 30 °C, and the polymerization time at 35 min to obtain the hydrogel electrolyte of Comparative Example 2.

[0088] In each of the examples and comparative examples, the zinc salt used is zinc sulfate heptahydrate, the manganese salt used is manganese sulfate monohydrate, the polymerizable monomer containing sulfonic group used is methacryloylethyl sulfobetaine, and the water used is deionized water.

[0089] Experiment: Assemble the hydrogel electrolytes obtained in Examples 1 to 3 and Comparative Example 1 and Comparative Example 2 of the present invention with the positive electrode and the negative electrode to obtain zinc ion batteries.

[0090] Test: In each of the above examples, conduct various tests on the zinc ion batteries of Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 2. The test results are shown in Table 1 and Figure 2 .

[0091] Table 1 Charge and Discharge Performance Test

[0092]

[0093]

[0094] As can be seen from the above table, compared with the zinc-ion batteries of Comparative Example 1 and Comparative Example 2, the zinc-ion batteries prepared in Examples 1 to 3 all have excellent initial discharge specific capacity and capacity retention rate, high battery efficiency, good cycle performance, and longer service life. The quality of the zinc-ion batteries prepared in Examples 1 to 3 is higher than that of Comparative Example 1 and Comparative Example 2. The preparation processes of the above-mentioned examples are simple, and the assembled zinc-ion batteries show good cycle stability, improving the cycle life of the zinc-ion batteries.

[0095] Specifically, Figure 2 is the impedance (EIS) test chart of the zinc-ion batteries assembled with the hydrogel electrolytes of Example 2 of the present invention and Comparative Example 1 and Comparative Example 2. From Figure 2 it can be seen that the charge transfer resistance of the zinc-ion battery assembled in Example 2 is smaller, and the interface compatibility of the zinc-ion battery assembled in Example 2 with the cathode material is better, which can improve the charge and discharge efficiency of the battery.

[0096] Figure 3 is the cyclic voltammetry (CV) curve chart test of the zinc-ion batteries assembled with the hydrogel electrolytes prepared in Example 2 and Comparative Example 1 and Comparative Example 2. From Figure 3 it can be seen that in Example 2, when the potential reaches 1.3V, its current value is larger, indicating a faster reaction rate and better cycle performance. That is to say, the cycle performance of the zinc-ion batteries in Examples 1 to 4 is better than that of Comparative Example 1 and Comparative Example 2, proving that the hydrogel electrolyte prepared by the method of the present invention has good performance, excellent cycle stability, and high efficiency, significantly improving the cycle performance and safety performance of the zinc-ion batteries.

[0097] The above-mentioned embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A method for preparing a hydrogel electrolyte, characterized in that: The following steps are involved: Providing a thickener, adding the thickener into water, and stirring evenly to obtain a thickened solution; Providing zinc salt, manganese salt, acrylamide, a crosslinking agent and a polymerizable monomer containing a sulfonic acid group, adding the zinc salt, the manganese salt, the acrylamide, the crosslinking agent and the polymerizable monomer containing a sulfonic acid group into the thickening solution, stirring evenly, to obtain a crosslinking solution; Providing an initiator, adding the initiator into water, and stirring evenly to obtain an initiating solution; The initiating solution is added to the cross-linking solution, stirred evenly, and then poured into a mold to carry out a polymerization reaction to obtain a hydrogel electrolyte.

2. The method for preparing a hydrogel electrolyte according to claim 1, characterized in that: Before the operation of adding the initiating solution into the cross-linking solution, a catalyst is provided, the catalyst is added into water, stirred evenly to obtain a catalytic solution, and the catalytic solution is added into the cross-linking solution.

3. The method for preparing a hydrogel electrolyte according to claim 2, characterized in that: Before the operation of adding the initiating solution into the cross-linking solution, anhydrous copper sulfate is provided, the anhydrous copper sulfate is added into water, stirred evenly to obtain an anhydrous copper sulfate solution, and the anhydrous copper sulfate solution is added into the cross-linking solution.

4. The method for preparing a hydrogel electrolyte according to claim 3, characterized in that: The catalyst is tannic acid.

5. The method for preparing a hydrogel electrolyte according to claim 1, characterized in that: The thickener is sodium carboxymethyl cellulose.

6. The method for preparing a hydrogel electrolyte according to claim 1, characterized in that: The sulfonic acid group-containing polymerizable monomer is at least one of methacryloylethyl sulfobetaine, vinyl sulfonic acid, styrene sulfonic acid, methacrylic acid sulfonic acid, isoprene sulfonic acid, 2-hydroxy-3-allylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, acrylamide butyl sulfonic acid, acryloxybutyl sulfonic acid, 1-allyloxy-2-hydroxysulfonic acid, sodium allyl sulfonate, sodium methallyl sulfonate, sodium styrene sulfonate, vinyl sulfonic acid and 2-methyl-acryloyloxypropyl sulfonic acid.

7. The method for preparing a hydrogel electrolyte according to claim 1, characterized in that: In the operation of pouring into the mold and carrying out polymerization reaction, the polymerization temperature is controlled to be 25° C. to 35° C., and the polymerization time is controlled to be 20 min to 50 min.

8. The method for preparing a hydrogel electrolyte according to any one of claims 1 to 7, characterized in that: In the operation of adding the thickener into water and stirring evenly, the thickener is divided into at least two portions, and each portion of the thickener is added into the water at intervals, and the stirring time is controlled to be 2 hours to 3 hours.

9. A hydrogel electrolyte, characterized in that: The hydrogel electrolyte is prepared by the preparation method of any one of claims 1 to 8.

10. A zinc ion battery comprising a positive electrode, a negative electrode and a hydrogel electrolyte, characterized in that: The electrolyte is the hydrogel electrolyte according to claim 9.

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