A zwitterionic liquid-based solid electrolyte membrane, its preparation method and application

Abstract

The present invention belongs to the field of electrochemistry, and specifically relates to an amphoteric ionic liquid-based solid electrolyte membrane, its preparation method and application, including the following steps: Using 3-(1-vinyl-3-imidazolyl) propanesulfonate powder and N,N'-methylenebisacrylamide as crosslinking agents, adding methanol and water to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, and then adding a photoinitiator. Under ultraviolet light irradiation, a photocatalytic polymerization reaction occurs to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid membrane; soaking the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid membrane in an alkaline solution for ion exchange to obtain an amphoteric ionic liquid-based solid electrolyte membrane. Compared with a single-sex ionic liquid membrane, the 3-(1-vinyl-3-imidazolyl) propanesulfonate membrane has a higher conductivity, improving the problem of low conductivity of artificial polymer electrolyte membranes.

Description

Technical Field

[0001] The invention belongs to the field of electrochemistry, and in particular relates to a zwitterionic liquid-based solid electrolyte membrane and a preparation method and application thereof. Background Art

[0002] Flexible electronic devices are experiencing a period of rapid development, and traditional rigid batteries can no longer meet the increasingly diverse usage environments. Among flexible energy storage devices, flexible zinc-air batteries have become a hot topic of research due to their excellent safety, low cost, and high theoretical energy density.

[0003] Flexible zinc-air batteries consist of a zinc anode, an air cathode, and a conductive OH - The solid electrolyte membrane overcomes the problems of alkaline electrolyte leakage and solution evaporation and drying, and gives the battery a certain plasticity. Therefore, the development of solid electrolytes with high ion conductivity and water retention can promote the development of flexible zinc-air batteries.

[0004] The existing preparation method usually uses artificial polymer materials such as polyvinyl alcohol, polyacrylic acid and polyacrylamide as raw materials to prepare solid electrolyte membranes. However, the electrolyte membrane prepared by this method stores electrolytes due to its network structure. - The conduction mainly depends on the adsorption of electrolyte by gel, resulting in relatively low conductivity. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a zwitterionic liquid-based solid electrolyte membrane and a preparation method and application thereof. A zwitterionic liquid solid electrolyte membrane is prepared using 3-(1-vinyl-3-imidazolyl)propanesulfonate as a raw material. The solid electrolyte membrane formed by 3-(1-vinyl-3-imidazolyl)propanesulfonate is an alkaline anion exchange membrane. There are positive and negative charges in its structure that can be tightly combined with water molecules, ensuring a high water content. The fast ion migration channel ensures high conductivity. The polymerization between monomers promotes the mechanical properties of the electrolyte. It is applied to batteries and can withstand complex and changeable usage conditions.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for preparing a zwitterionic liquid-based solid electrolyte membrane comprises the following steps:

[0008] Using 3-(1-vinyl-3-imidazolyl) propanesulfonate powder as a monomer and N,N'-methylenebisacrylamide as a crosslinking agent, adding a mixed solvent of methanol and water to the monomer and the crosslinking agent to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, adding a photoinitiator to the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, and under ultraviolet light irradiation, a photocatalytic polymerization reaction occurs to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film.

[0009] Soaking the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film in an alkaline solution for ion exchange to obtain an amphoteric ionic liquid-based solid electrolyte membrane.

[0010] In the present invention, 3-(1-vinyl-3-imidazolyl) propanesulfonate powder is used as a monomer and N,N'-methylenebisacrylamide as a crosslinking agent, adding a mixed solvent of methanol and water thereto to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, adding a photoinitiator to the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, and under ultraviolet light irradiation, a photocatalytic polymerization reaction occurs to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film. The vinyl group at the end of 3-(1-vinyl-3-imidazolyl) propanesulfonate polymerizes into a chain and crosslinks with N,N'-methylenebisacrylamide under ultraviolet light irradiation to form a network structure, and the molecular chains therein change from disordered to ordered, forming a solid propanesulfonate electrolyte membrane; soaking the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film in an alkaline solution for ion exchange, and the cationic and anionic groups inherent in the amphoteric ionic liquid itself construct a channel for ion transport to obtain an amphoteric ionic liquid-based solid electrolyte membrane.

[0011] In a preferred embodiment of the present invention, the mass ratio of 3-(1-vinyl-3-imidazolyl) propanesulfonate powder to N,N'-methylenebisacrylamide is 20-30:1.

[0012] In a preferred embodiment of the present invention, the mass fraction of 3-(1-vinyl-3-imidazolyl) propanesulfonate powder in the mixed solvent of methanol and water is 20%-60%.

[0013] In a preferred embodiment of the present invention, the photoinitiator is one of 2-hydroxy-2-methyl-1-phenylpropanone, benzoin ethyl ether, 2-hydroxy-2-methylpropiophenone, and azodiisobutyramidine hydrochloride, and the mass fraction of the photoinitiator in the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution is 2%-5%.

[0014] In a preferred embodiment of the present invention, in the mixed solvent of methanol and water, the mass ratio of methanol to water is 1-5:1.

[0015] In a preferred embodiment of the present invention, the alkaline solution is a mixed solution of 1 - 6 M KOH and 0.1 - 0.2 M Zn(Ac)₂, and the ion exchange time is 24 h - 72 h.

[0016] In a preferred embodiment of the present invention, the method for preparing the 3-(1-vinyl-3-imidazolyl) propanesulfonate powder comprises the following steps:

[0017] Dissolve 1-vinylimidazole in acetone to obtain a first solution, dissolve 1,3-propanesultone in acetone to obtain a second solution, mix the second solution with the first solution under a nitrogen atmosphere, stir at room temperature to obtain a mixed solution, and perform post-treatment on the mixed solution to obtain the (3-(1-vinyl-3-imidazolyl) propanesulfonate) powder.

[0018] According to the method for preparing the zwitterionic liquid-based solid electrolyte membrane as claimed in claim 7, wherein the molar ratio of 1-vinylimidazole to 1,3-propanesultone is 1 - 5:1, the dosage ratio of 1-vinylimidazole to acetone is 0.1 mol:60 mL - 120 mL, and the dosage ratio of 1,3-propanesultone to acetone is 0.1 mol:40 mL - 100 mL.

[0019] 。

[0020] Another object of the present invention is to provide a zwitterionic liquid-based solid electrolyte membrane prepared by the preparation method described in any one of the above.

[0021] The third object of the present invention is to provide an application of the zwitterionic liquid-based solid electrolyte membrane described above in zinc-air batteries and zinc-ion batteries.

[0022] Each structural unit of the zwitterionic liquid carries a pair of opposite charges. After cross-linking, a zwitterionic solid gel can be formed. Due to the unique structures of the anions and cations it carries, it has special properties. First, although the zwitterion is electrically neutral, the positive and negative charges that coexist in its structure are easily combined with water molecules and solvated, resulting in the formation of a water layer on the surface and showing super hydrophilicity. Second, there is a strong electrostatic interaction between zwitterionic liquids, which is caused by the charged groups and counter free ions of the structural units. The existence of the strong electrostatic interaction forms non-interfering ion transport channels in the zwitterionic liquid solid electrolyte membrane. Benefiting from the various advantages of the zwitterionic liquid, the present invention uses a chemical substance 3-(1-vinyl-3-imidazolyl) propanesulfonate with a unique structure as a raw material to prepare a zwitterionic liquid solid electrolyte membrane. The solid electrolyte membrane formed by 3-(1-vinyl-3-imidazolyl) propanesulfonate is an alkaline anion exchange membrane. In its structure, there are positive and negative charges that can be tightly combined with water molecules, ensuring a high water content; the fast ion migration channels ensure high conductivity; the polymerization between monomers promotes the mechanical properties of the electrolyte. When applied to a battery, it can withstand complex and variable usage conditions.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] 1. The present invention uses 3-(1-vinyl-3-imidazolyl) propane sulfonate powder as a monomer and N,N'-methylenebisacrylamide as a crosslinking agent, adds a mixed solvent of methanol and water to obtain a 3-(1-vinyl-3-imidazolyl) propane sulfonate solution, adds a photoinitiator to the 3-(1-vinyl-3-imidazolyl) propane sulfonate solution, and generates a photocatalytic polymerization reaction under ultraviolet light to obtain a 3-(1-vinyl-3-imidazolyl) propane sulfonate solid film. The vinyl groups at the end of 3-(1-vinyl-3-imidazolyl)propanesulfonate are polymerized into chains, and cross-linked with N,N'-methylenebisacrylamide to form a network structure under the irradiation of ultraviolet light, wherein the molecular chains are transformed from disorder to order, forming a solid propanesulfonate electrolyte membrane; the 3-(1-vinyl-3-imidazolyl)propanesulfonate solid membrane is immersed in an alkaline solution for ion exchange, wherein the anion and cation groups of the zwitterionic liquid itself construct a channel for the transmission of ions, and a zwitterionic liquid-based solid electrolyte membrane is obtained. The present invention uses 3-(1-vinyl-3-imidazolyl)propanesulfonate, a chemical substance with a unique structure, as a raw material to prepare a zwitterionic liquid solid electrolyte membrane. The solid electrolyte membrane formed by 3-(1-vinyl-3-imidazolyl)propanesulfonate is an alkaline anion exchange membrane, and there are positive and negative charges in its structure that can be tightly combined with water molecules, ensuring a high water content, and a fast ion migration channel to ensure high conductivity. The polymerization between monomers promotes the mechanical properties of the electrolyte, and it is applied to batteries and can withstand complex and changeable use conditions.

[0025] 2. The present invention highlights the structural advantages and excellent performance of 3-(1-vinyl-3-imidazolyl) propane sulfonate-based electrolytes by comparing them with 1-vinyl-3-butylimidazolium bromide monoionic liquid solid electrolytes. Compared with monoionic liquid membranes, 3-(1-vinyl-3-imidazolyl) propane sulfonate membranes have higher conductivity, which improves the problem of low conductivity of artificial polymer electrolyte membranes. 3-(1-vinyl-3-imidazolyl) propane sulfonate is applied to zinc-air batteries, which can make electronic devices operate under bending conditions, and the voltage remains stable after multiple bending. The structural design and application of 3-(1-vinyl-3-imidazolyl) propane sulfonate contribute to the development of zinc-air batteries. With its unique structure, it can also be applied to other batteries, further promoting the development and progress of energy storage devices.

[0026] 3. The present invention designs the structure of zwitterionic liquids. By utilizing the unique structural advantages, the prepared electrolyte membrane has high hydrophilicity and high ionic conductivity. Through the design of the substance structure, 3-(1-vinyl-3-imidazolium) propanesulfonate powder is prepared. Compared with the monovalent ionic liquid 1-vinyl-3-butylimidazolium bromide electrolyte, the prepared zwitterionic liquid 3-(1-vinyl-3-imidazolium) propanesulfonate membrane has higher conductivity. By controlling the concentration of 3-(1-vinyl-3-imidazolium) propanesulfonate in the membrane, under the conditions of high concentration and high temperature, the electrolyte membrane achieves higher conductivity. By controlling the length of the photocatalysis time, a flexible electrolyte membrane is prepared, realizing the bending application of the zinc-air battery. The above inventions and designs have promoted the development of flexible zinc-air batteries and provided assistance for the application of zwitterionic liquid electrolyte membranes in energy storage devices. Description of the Drawings

[0027] Figure 1 It is the reaction mechanism and process of crosslinking the zwitterionic liquid 3-(1-vinyl-3-imidazolium) propanesulfonate of the present invention with N,N'-methylenebisacrylamide to form a film.

[0028] Figure 2 It is a comparison of the structural formulas of 3-(1-vinyl-3-imidazolium) propanesulfonate and 1-vinyl-3-butylimidazolium bromide of the present invention.

[0029] Figure 3 It is the FTIR spectrum of 3-(1-vinyl-3-imidazolium) propanesulfonate and 1-vinyl-3-butylimidazolium bromide of the present invention.

[0030] Figure 4 It is the XPS spectrum of 3-(1-vinyl-3-imidazolium) propanesulfonate and 1-vinyl-3-butylimidazolium bromide of the present invention.

[0031] Figure 5 It is the EDX spectrum of 3-(1-vinyl-3-imidazolium) propanesulfonate of the present invention.

[0032] Figure 6 It is the EDX spectrum of 1-vinyl-3-butylimidazolium bromide of the present invention.

[0033] Figure 7 It is the conductivity-temperature relationship diagram of 3-(1-vinyl-3-imidazolium) propanesulfonate and 1-vinyl-3-butylimidazolium bromide at different concentrations.

[0034] Figure 8The zinc-air battery assembled with the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid electrolyte membrane of the present invention, wherein 1 is the air cathode, 2 is the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid electrolyte membrane, and 3 is the zinc anode.

[0035] Figure 9 The open circuit voltage of the battery assembled with the electrolyte of 3-(1-vinyl-3-imidazolyl) propanesulfonate and 1-vinyl-3-butylimidazolium bromide of the present invention.

[0036] Figure 10 The comparison of the discharge time of the battery assembled with the electrolyte of 3-(1-vinyl-3-imidazolyl) propanesulfonate and 1-vinyl-3-butylimidazolium bromide of the present invention under a constant current of 1 mA / cm 2 of.

[0037] Figure 11 The polarization curve of the 3-(1-vinyl-3-imidazolyl) propanesulfonate and 1-vinyl-3-butylimidazolium bromide-based ZAB of the present invention.

[0038] Figure 12 The power density curve of the 3-(1-vinyl-3-imidazolyl) propanesulfonate and 1-vinyl-3-butylimidazolium bromide-based ZAB of the present invention.

[0039] Figure 13 The measurement of the voltage stability of the 3-(1-vinyl-3-imidazolyl) propanesulfonate-based electrolyte membrane of the present invention when applied to a flexible zinc-air battery at different bending angles.

[0040] Figure 14 The assembly diagram of the 3-(1-vinyl-3-imidazolyl) propanesulfonate-based zinc-air battery of the present invention.

[0041] Figure 15 The actual application diagram of the 3-(1-vinyl-3-imidazolyl) propanesulfonate-based zinc-air battery of the present invention. Detailed implementation manners

[0042] The following is a detailed description in conjunction with the embodiments of the present invention, using preferred embodiments and accompanying drawings. The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0043] It should be noted that all the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the protection scope of the present invention. Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the following embodiments of the present invention can be obtained through market purchase or prepared by existing methods.

[0044] Example 1

[0045] A preparation method of an amphoteric ionic liquid-based solid electrolyte membrane includes the following steps:

[0046] (1) Dissolve 0.1 mol of 1-vinylimidazole in 60 mL of acetone to obtain solution A, and then dissolve 0.1 mol of 1,3-propane sultone in 40 mL of acetone to obtain solution B. Drop solution B into solution A under a nitrogen environment at 0 °C. After stirring at room temperature for three days, filter the obtained mixed solution to obtain solid powder, wash it three times with acetone, and dry it under vacuum at room temperature to obtain 3-(1-vinyl-3-imidazolyl)propane sulfonate powder.

[0047] (2) Place 0.2 g of the 3-(1-vinyl-3-imidazolyl)propane sulfonate powder prepared in step (1) and 0.01 g of N,N'-methylenebisacrylamide as a cross-linking agent in a test tube, and drop 103 μL of methanol and 40 μL of water into it to dissolve the solid and prepare a 60% mass concentration solution of 3-(1-vinyl-3-imidazolyl)propane sulfonate.

[0048] (3) Add 2-hydroxy-2-methyl-1-phenylpropanone, a photoinitiator with a mass fraction of 2%, to the 3-(1-vinyl-3-imidazolyl)propane sulfonate solution, shake and stir evenly. Close a silica gel gasket with a 16 mm * 16 mm round hole on a light-transmitting glass plate, drop the 3-(1-vinyl-3-imidazolyl)propane sulfonate solution into the round hole, cover it with a glass plate, irradiate it with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 3-(1-vinyl-3-imidazolyl)propane sulfonate solid membrane.

[0049] (4) Immerse the 3-(1-vinyl-3-imidazolyl)propane sulfonate solid membrane in a solution containing 6 M KOH and 0.2 M Zn(AC)2 for 24 hours for ion exchange to obtain a 3-(1-vinyl-3-imidazolyl)propane sulfonate solid electrolyte membrane.

[0050] Example 2

[0051] A preparation method of an amphoteric ionic liquid-based solid electrolyte membrane includes the following steps:

[0052] (1) Dissolve 0.1 mol of 1-vinylimidazole in 60 mL of acetone to obtain solution A. Then dissolve 0.1 mol of 1,3-propanesultone in 40 mL of acetone to obtain solution B. Under a nitrogen environment at 0 °C, add solution B dropwise to solution A. After stirring at room temperature for three days, filter the resulting mixed solution to obtain a solid powder, wash it three times with acetone, and dry it under vacuum at room temperature to obtain 3-(1-vinyl-3-imidazolyl)propanesulfonate powder.

[0053] (2) Place 0.2 g of the 3-(1-vinyl-3-imidazolyl)propanesulfonate powder prepared in step (1) and 0.01 g of N,N'-methylenebisacrylamide as a cross-linking agent in a test tube, add 166 μL of methanol and 67 μL of water dropwise thereto, dissolve the solid, and prepare a 50% mass concentration solution of 3-(1-vinyl-3-imidazolyl)propanesulfonate.

[0054] (3) Add 2-hydroxy-2-methyl-1-phenylpropanone, a photoinitiator with a mass fraction of 2%, to the 3-(1-vinyl-3-imidazolyl)propanesulfonate solution, stir it evenly by shaking. Close a silica gel gasket with a 16 mm * 16 mm round hole tightly on a light-transmitting glass plate, drop the 3-(1-vinyl-3-imidazolyl)propanesulfonate solution into the round hole, cover it with a glass plate, irradiate it with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 3-(1-vinyl-3-imidazolyl)propanesulfonate solid film.

[0055] (4) Immerse the 3-(1-vinyl-3-imidazolyl)propanesulfonate solid film in a solution containing 6 M KOH and 0.2 M Zn(AC)₂ for 24 hours for ion exchange to obtain a 3-(1-vinyl-3-imidazolyl)propanesulfonate solid electrolyte film.

[0056] Example 3

[0057] A preparation method of a zwitterionic liquid-based solid electrolyte film, comprising the following steps:

[0058] (1) Dissolve 0.1 mol of 1-vinylimidazole in 60 mL of acetone to obtain solution A. Then dissolve 0.1 mol of 1,3-propanesultone in 40 mL of acetone to obtain solution B. Under a nitrogen environment at 0 °C, add solution B dropwise to solution A. After stirring at room temperature for three days, filter the resulting mixed solution to obtain a solid powder, wash it three times with acetone, and dry it under vacuum at room temperature to obtain 3-(1-vinyl-3-imidazolyl)propanesulfonate powder.

[0059] (2) Place 0.2 g of the 3-(1-vinyl-3-imidazolyl)propanesulfonate powder prepared in step (1) and 0.01 g of N,N'-methylenebisacrylamide as a crosslinking agent in a test tube, add 250 μL of methanol and 100 μL of water dropwise thereto to dissolve the solid, and prepare a 3-(1-vinyl-3-imidazolyl)propanesulfonate solution with a mass concentration of 40%.

[0060] (3) Add 2-hydroxy-2-methyl-1-phenylpropanone, a photoinitiator with a mass fraction of 2%, to the 3-(1-vinyl-3-imidazolyl)propanesulfonate solution, stir evenly by shaking, place a silica gel gasket close to a 16 mm * 16 mm round hole on a light-transmitting glass plate, drop the 3-(1-vinyl-3-imidazolyl)propanesulfonate solution into the round hole, cover it with a glass plate, irradiate with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 3-(1-vinyl-3-imidazolyl)propanesulfonate solid film.

[0061] (4) Immerse the 3-(1-vinyl-3-imidazolyl)propanesulfonate solid film in a solution containing 6 M KOH and 0.2 M Zn(AC)2 for 24 hours for ion exchange to obtain a 3-(1-vinyl-3-imidazolyl)propanesulfonate solid electrolyte membrane.

[0062] Example 4

[0063] A preparation method of a zwitterionic liquid-based solid electrolyte membrane, comprising the following steps:

[0064] (1) Dissolve 0.1 mol of 1-vinylimidazole in 60 mL of acetone to obtain solution A, then dissolve 0.1 mol of 1,3-propanesultone in 40 mL of acetone to obtain solution B. Drop solution B into solution A under a nitrogen environment at 0 °C, stir the resulting mixed solution at room temperature for three days, filter the mixed solution to obtain a solid powder, wash it three times with acetone, and dry it under vacuum at room temperature to obtain 3-(1-vinyl-3-imidazolyl)propanesulfonate powder.

[0065] (2) Place 0.25 g of the 3-(1-vinyl-3-imidazolyl)propanesulfonate powder prepared in step (1) and 0.01 g of N,N'-methylenebisacrylamide as a crosslinking agent in a test tube, add 250 μL of methanol and 200 μL of water dropwise thereto to dissolve the solid, and prepare a 3-(1-vinyl-3-imidazolyl)propanesulfonate solution with a mass concentration of 30%.

[0066] (3) Add 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photoinitiator with a mass fraction of 3% to the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, stir evenly by shaking, place a silica gel gasket with a 16 mm * 16 mm round hole closely on a light-transmitting glass plate, drop the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution into the round hole, cover it with a glass plate, irradiate with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film.

[0067] (4) Immerse the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film in a solution containing 6 M KOH and 0.2 M Zn(AC)2 for 24 hours for ion exchange to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid electrolyte film.

[0068] Example 5

[0069] A preparation method of a zwitterionic liquid-based solid electrolyte membrane, comprising the following steps:

[0070] (1) Dissolve 0.2 mol of 1-vinylimidazole in 200 mL of acetone to obtain solution A, then dissolve 0.1 mol of 1,3-propanesultone in 80 mL of acetone to obtain solution B. Drop solution B into solution A under a nitrogen environment at 0 °C. After stirring at room temperature for three days, filter the obtained mixed solution to obtain solid powder, wash it three times with acetone, and dry it under vacuum at room temperature to obtain 3-(1-vinyl-3-imidazolyl) propanesulfonate powder.

[0071] (2) Place 0.3 g of the 3-(1-vinyl-3-imidazolyl) propanesulfonate powder prepared in step (1) and 0.01 g of N,N'-methylenebisacrylamide as a crosslinking agent in a test tube, drop 103 μL of methanol and 40 μL of water into it to dissolve the solid, and prepare a 3-(1-vinyl-3-imidazolyl) propanesulfonate solution with a mass concentration of 60%.

[0072] (3) Add 2-hydroxy-2-methyl-1-phenylpropan-1-one as a photoinitiator with a mass fraction of 5% to the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, stir evenly by shaking, place a silica gel gasket with a 16 mm * 16 mm round hole closely on a light-transmitting glass plate, drop the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution into the round hole, cover it with a glass plate, irradiate with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film.

[0073] (4) Immerse the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid membrane in a solution containing 6 M KOH and 0.2 M Zn(AC)₂ for 48 hours for ion exchange to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid electrolyte membrane.

[0074] Example 6

[0075] A method for preparing an amphoteric ionic liquid-based solid electrolyte membrane, comprising the following steps:

[0076] (1) Dissolve 0.5 mol of 1-vinylimidazole in 300 mL of acetone to obtain solution A, and then dissolve 0.1 mol of 1,3-propane sultone in 100 mL of acetone to obtain solution B. Drop solution B into solution A under a nitrogen environment at 0 °C. After stirring at room temperature for three days, filter the resulting mixed solution to obtain solid powder, wash it three times with acetone, and dry it under vacuum at room temperature to obtain 3-(1-vinyl-3-imidazolyl) propanesulfonate powder.

[0077] (2) Place 0.2 g of the 3-(1-vinyl-3-imidazolyl) propanesulfonate powder prepared in step (1) and 0.01 g of N,N'-methylenebisacrylamide as a crosslinking agent in a test tube, and add 103 μL of methanol and 40 μL of water to dissolve the solid to prepare a 60% mass concentration 3-(1-vinyl-3-imidazolyl) propanesulfonate solution.

[0078] (3) Add 2-hydroxy-2-methyl-1-phenylpropanone, a photoinitiator with a mass fraction of 2%, to the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, shake and stir evenly. Place a silica gel gasket with a 16 mm * 16 mm round hole closely on a transparent glass plate, drop the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution into the round hole, cover it with a glass plate, irradiate it with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid membrane.

[0079] (4) Immerse the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid membrane in a solution containing 6 M KOH and 0.2 M Zn(AC)₂ for 72 hours for ion exchange to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid electrolyte membrane.

[0080] Comparative Example 1

[0081] A method for preparing a 1-vinyl-3-butylimidazolium bromide solid electrolyte membrane, comprising the following steps:

[0082] (1) 0.2 g of powdered 1-vinyl-3-butylimidazolium bromide and 0.01 g of N,N'-methylenebisacrylamide as a cross-linking agent were placed in a test tube, and 103 μL of methanol and 40 μL of water were added dropwise to dissolve the solid to prepare a 1-vinyl-3-butylimidazolium bromide solution with a mass concentration of 60%.

[0083] (2) Add 2% by mass of a photoinitiator, 2-hydroxy-2-methyl-1-phenylacetone, to the 1-vinyl-3-butylimidazolium bromide solution, shake and stir evenly, place a silicone gasket with a 16 mm*16 mm round hole on a light-transmitting glass plate, drop the 1-vinyl-3-butylimidazolium bromide solution into the round hole, cover the hole with a layer of glass plate, irradiate with ultraviolet light for 10 min, and irradiate the reverse side for 5 min to obtain a 1-vinyl-3-butylimidazolium bromide solid film.

[0084] (3) The 1-vinyl-3-butylimidazolium bromide solid membrane was immersed in a solution containing 6 M KOH and 0.2 M Zn(AC)2 for 72 hours to perform ion exchange, so as to obtain a 1-vinyl-3-butylimidazolium bromide solid electrolyte membrane.

[0085] Results Analysis

[0086] 3-(1-vinyl-3-imidazolyl)propanesulfonate, abbreviated as VIPS, N,N'-methylenebisacrylamide, abbreviated as MBAA, 1-vinyl-3-butylimidazolium bromide, abbreviated as VBIMBr.

[0087] The process of synthesizing the VIPS membrane of the present invention is to first prepare VIPS powder, add a certain proportion of water and methanol thereto, oscillate and stir to dissolve the powder, add a photoinitiator, polymerize into a membrane under ultraviolet light, show good flexibility, and change color after ion exchange.

[0088] Figure 1 The present invention discloses a reaction mechanism and process of cross-linking film formation of zwitterionic liquid VIPS and MBAA. The vinyl groups at the ends of VIPS are polymerized into chains, which are cross-linked with MBAA to form a network structure under the irradiation of ultraviolet light. The molecular chains therein are transformed from disorder to order, forming a solid VIPS electrolyte membrane. The electrolyte is immersed in a solution containing 6 M KOH and 0.2 M Zn(Ac)2 for ion exchange, wherein the anionic and cationic groups of the zwitterionic liquid itself construct channels for the transmission of ions.

[0089] Figure 2Structural formula comparison of VIPS and VBIMBr of the present invention. Compared with the zwitterionic liquid VBIMBr, the zwitterionic liquid VIPS itself has a pair of charges with opposite electricities, so it has an extremely high ionic group density, making the zwitterionic hydrogel have strong affinity.

[0090] Figure 3 FTIR spectra of VIPS and VBIMBr of the present invention Figure 4 XPS spectra of VIPS and VBIMBr of the present invention. The functional group structures of the two were compared. It was found that in the spectrum of VIPS, two obvious absorption peaks appeared at 1031 and 1180 cm -1 . This is attributed to the S=O stretching vibration of the sulfate group in its structure. In the XPS spectrum, it was found that there was a sharp peak attributed to S 2p at 231.2 eV in VIPS. This result further illustrates the structural differences between VIPS and VBIMBr.

[0091] Figure 5 EDX spectrum of VIPS of the present invention Figure 6 EDX spectrum of VBIMBr of the present invention. Elemental analysis was carried out on the VIPS and VBIMBr electrolyte membranes, and it was found that there was an obvious S element in VIPS.

[0092] Figure 7 Conductivity-temperature relationship diagrams of VIPS and VBIMBr with different concentrations of the present invention. Conductivity tests were carried out on the electrolyte membranes of 30 wt%, 40 wt%, 50 wt%, 60 wt% VIPS and 60 wt% VBIMBr at different temperatures, and it was found that the conductivity was proportional to the temperature. At the same concentration, the conductivity of VIPS was better than that of VBIMBr.

[0093] Figure 8 Zinc-air battery assembled with the VIPS solid electrolyte membrane of the present invention. Among them, 1 is the air cathode, 2 is the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid electrolyte membrane, 3 is the zinc anode. The reaction equation of the air cathode is: O2 + 2H2O + 4e - →4OH - , and the reaction equation of the zinc anode is: Zn + 4OH - →ZnO + 2H2O + 4e - . Through the button battery mold, the zinc anode, the VIPS solid electrolyte membrane, and the air cathode were assembled, and the reaction formulas during charge and discharge were shown. Among them, the air cathode is nickel foam loaded with catalysts Pt / C and Ir / C. Zinc-air batteries based on VIPS and VBIMBr electrolytes were combined by the above method, and their electrochemical performances were compared.

[0094] Figure 9 is the open-circuit voltage of the battery assembled with VIPS and VBIMBr electrolytes of the present invention. It is found that the VIPS-based ZAB has a higher open-circuit voltage.

[0095] Figure 10 is the comparison of the discharge time of the battery assembled with VIPS and VBIMBr electrolytes under a constant current of 1 mA / cm 2 . It is found that the VIPS-based ZAB lasts longer during the discharge process, showing the structural advantages of zwitterionic liquids.

[0096] Figure 11 are the polarization curves of VIPS- and VBIMBr-based zinc-air batteries. The zinc-air battery is abbreviated as ZAB. It is found that the VIPS-based ZAB shows significant advantages under charge and discharge conditions. Taking the current density at 40 mA / cm 2 as an example, during charging, the voltage of the VIPS-based ZAB is 490 mV lower than that of the VBIMBr-based one, and during discharge, it is 220 mV higher, showing excellent charge and discharge capabilities.

[0097] Figure 12 are the power density curves of VIPS- and VBIMBr-based zinc-air batteries. It is found that the VIPS-based ZAB has a higher peak power density, proving that when the ZAB is working, the VIPS electrolyte membrane can output higher power, further demonstrating that zwitterionic liquids help improve the battery's working ability.

[0098] Figure 13 is the voltage measurement of the VIPS-based solid electrolyte membrane applied to the zinc-air battery bent at different angles. It is found that the battery voltages at 0 °C, 90 °C, and 180 °C of bending can still remain stable.

[0099] Figure 14 is the assembly diagram of the 3-(1-vinyl-3-imidazolyl) propanesulfonate-based zinc-air battery of the present invention, Figure 15 is the actual application diagram of the 3-(1-vinyl-3-imidazolyl) propanesulfonate-based zinc-air battery of the present invention. It can be seen that in the case of connecting three batteries in series, the LED bulb and the bouquet string lights are successfully lit, proving that this electrolyte membrane can be applied to real life and has certain development prospects.

[0100] In summary, by comparing with the VBIMBr unipolar ionic liquid solid electrolyte, the structural advantages and excellent properties of the VIPS-based electrolyte are highlighted. Compared with the unipolar ionic liquid membrane, the VIPS membrane has higher conductivity, which improves the problem of low conductivity of artificial polymer electrolyte membranes. When the VIPS membrane is applied to a zinc-air battery, the electronic device can operate under bending conditions, and the voltage remains stable after multiple bends. The structural design and application of VIPS contribute to the development of zinc-air batteries and can also be applied to other batteries by virtue of its unique structure, further promoting the development and progress of energy storage devices.

[0101] It should be noted that when the present invention involves a numerical range, it should be understood that any value between the two endpoints of each numerical range and the two endpoints can be selected. Since the steps and methods adopted are the same as those of the embodiments, in order to prevent repetition, the present invention describes the preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0102] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the present invention and its equivalent technologies, the present invention also intends to include these changes and deformations.

Claims

1. A preparation method of a zwitterionic liquid-based solid electrolyte membrane, characterized in that It includes the following steps: Using 3-(1-vinyl-3-imidazolyl) propanesulfonate powder as a monomer and N,N'-methylenebisacrylamide as a crosslinking agent, adding a mixed solvent of methanol and water to the monomer and the crosslinking agent to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solution; Adding a photoinitiator to the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution, and under ultraviolet light irradiation, a photocatalytic polymerization reaction occurs to obtain a 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film; Soaking the 3-(1-vinyl-3-imidazolyl) propanesulfonate solid film in an alkaline solution for ion exchange to obtain an amphoteric ionic liquid-based solid electrolyte membrane; The preparation method of the 3-(1-vinyl-3-imidazolyl) propanesulfonate powder includes the following steps: Dissolving 1-vinylimidazole in acetone to obtain a first solution, dissolving 1,3-propanesultone in acetone to obtain a second solution, mixing the second solution with the first solution under a nitrogen atmosphere, stirring at room temperature to obtain a mixed solution, and performing post-treatment on the mixed solution to obtain (3-(1-vinyl-3-imidazolyl) propanesulfonate) powder.

2. The preparation method of the zwitterionic liquid-based solid electrolyte membrane according to claim 1, characterized in that The mass ratio of 3-(1-vinyl-3-imidazolyl) propanesulfonate powder to N,N'-methylenebisacrylamide is 20-30:

1.

3. The preparation method of the zwitterionic liquid-based solid electrolyte membrane according to claim 1, characterized in that The mass fraction of 3-(1-vinyl-3-imidazolyl) propanesulfonate powder in the mixed solvent of methanol and water is 20%-60%.

4. The preparation method of the zwitterionic liquid-based solid electrolyte membrane according to claim 1, characterized in that, The photoinitiator is one of 2-hydroxy-2-methyl-1-phenylpropanone, benzoin ethyl ether, 2-hydroxy-2-methylacetophenone, and azodiisobutyramidine hydrochloride, and the mass fraction of the photoinitiator in the 3-(1-vinyl-3-imidazolyl) propanesulfonate solution is 2%-5%.

5. The preparation method of the zwitterionic liquid-based solid electrolyte membrane according to claim 1, characterized in that, In the mixed solvent of methanol and water, the mass ratio of methanol to water is 1-5:

1.

6. The preparation method of the zwitterionic liquid-based solid electrolyte membrane according to claim 1, characterized in that, The alkaline solution is a mixed solution of 1-6M KOH and 0.1-0.2M Zn(Ac)2, and the ion exchange time is 24h-72h.

7. The preparation method of the zwitterionic liquid-based solid electrolyte membrane according to claim 1, wherein The molar ratio of 1-vinylimidazole to 1,3-propanesultone is 1-5:1, the dosage ratio of 1-vinylimidazole to acetone is 0.1mol:60mL-120mL, and the dosage ratio of 1,3-propanesultone to acetone is 0.1mol:40mL-100mL.

8. An amphoteric ionic liquid-based solid electrolyte membrane prepared by the preparation method according to any one of claims 1-7.

9. Application of the amphoteric ionic liquid-based solid electrolyte membrane according to claim 8 in a zinc-air battery and a zinc-ion battery.

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