CN-122000274-A - Preparation method of beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane stable metallic zinc anode surface

Abstract

The invention discloses a preparation method of a beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane for stabilizing the surface of a metallic zinc negative electrode, which uses metallic zinc as a substrate, prepares mixed slurry of polyion elastomer and beta-cyclodextrin through a strategy of chemical polymerization and microphase separation, uniformly coats the obtained slurry on the metallic zinc substrate, builds a copolymer electrolyte membrane on the surface of the metallic zinc, and has the functions of corrosion protection, regulation and control of zinc ion transportation and inhibition of hydrogen evolution reaction. The beta-cyclodextrin modified polyion elastomer stable metal zinc negative electrode surface multifunctional copolymer electrolyte membrane has the physical properties of high breaking strength, strong flexibility and good conductivity, has a self-repairing function, and the internal ion grid structure can obviously improve the cycle life of a zinc metal battery in a water-based electrolyte.

Inventors

• BIN DUAN
• LI CONGCONG
• SUN JIYU
• YANG BEIBEI
• LU HONGBIN

Assignees

• 海安南通大学高端纺织研究院
• 南通大学

Dates

Publication Date

20260508

Application Date

20260127

Claims (10)

1. 1. The preparation method of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane stable metallic zinc anode surface is characterized by comprising the following steps of: step 1, mixing lithium bistrifluoromethylsulfonylimide, acryloyloxyethyl trimethyl ammonium chloride and deionized water, and stirring the mixture; Step 2, washing and layering the stirred sample in the step 1, and enriching to obtain a lower ionic liquid; Step 3, placing the ionic liquid obtained in the step 2 in a vacuum oven for drying; step 4, mixing the ionic liquid dried in the step 3 with butyl acrylate and azodiisobutyronitrile, and stirring the mixture; Step 5, placing the stirred sample in the step 4 in a vacuum oven for thermal polymerization to obtain a polyion elastomer; Step 6, dissolving the polyion elastomer obtained in the step 5 in acetone, adding beta-cyclodextrin to mix, and carrying out ultrasonic treatment on the mixture to obtain the copolymer electrolyte coating for stabilizing the surface of the zinc cathode; and 7, uniformly coating the copolymer electrolyte coating obtained in the step 6 on a clean metal zinc substrate, and naturally airing to obtain the surface uniform copolymer electrolyte membrane.
2. 2. The method for preparing the stable metallic zinc negative electrode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the dosage ratio of the lithium bistrifluoromethylsulfonyl imide to the acryloyloxyethyl trimethyl ammonium chloride to the deionized water in the step1 is 16 mmol:19 mmol:50 ml, the stirring time is 24 h, and the rotating speed is 150 r/min.
3. 3. The method for preparing the stable metallic zinc negative electrode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein in the step 2, a separating funnel is used for washing a sample, the dosage of deionized water is 50 ml each time, and the operation is repeated five times.
4. 4. The method for preparing the stable metallic zinc anode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the temperature of the vacuum oven in the step 3 is 80 ℃ and the time is 24 h.
5. 5. The method for preparing the stable metallic zinc negative electrode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the dosage ratio of the ionic liquid to the butyl acrylate in the step 4 is 4 mmol:12: 12 mmol:0.2. 0.2 mmol, the stirring time is 10 min, and the rotating speed is 150 r/min.
6. 6. The method for preparing the stable metallic zinc anode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the temperature of the vacuum oven in the step 5 is 60 ℃ and the time is 24 h.
7. 7. The method for preparing the stable metallic zinc anode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the dosage ratio of the polyion elastomer to the acetone in the step 6 is 4.8 mmol:10 ml:0.13 mmol, the power during ultrasonic treatment is 100W, the temperature is controlled at 25 ℃, and the time is 10 min.
8. 8. The method for preparing a stable metallic zinc anode surface of a beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein in the step 7, the metallic zinc purity in the metallic zinc substrate is 95%, the metallic zinc substrate is a zinc sheet, and the thickness of the metallic zinc substrate is 50 μm.
9. 9. The method for preparing the stable metallic zinc negative electrode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the coating method in the step 7 is knife coating, and the coating thickness is between 500 nm and 1000 nm.
10. 10. The method for preparing the stable metallic zinc anode surface of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane according to claim 1, wherein the room temperature environment for natural drying in the step 7 is 27 ℃ and the time is 24 h.

Description

Preparation method of beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane stable metallic zinc anode surface Technical Field The invention belongs to the technical field of modification of negative electrodes of water-based zinc metal batteries, and particularly relates to a preparation method of a stable metal zinc negative electrode surface of a beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane. Background Energy is an important material foundation for the survival and development of human society, and is critical for national life and national security. Along with the rapid development of intermittent energy sources such as solar energy, wind energy and the like, the development of an efficient energy storage system and the realization of large-scale storage and transportation of the energy sources have become important problems faced by human beings. Among many energy storage systems, aqueous Zinc Ion Batteries (AZIB) use aqueous solutions as electrolytes, have extremely high safety compared to flammable organic electrolytes, and metallic zinc has the advantages of low cost (earth zinc reserves are abundant), high theoretical specific capacity (820 mAh ·g -1 or 5855 mAh ·cm -3), low oxidation-reduction potential (compared to standard hydrogen electrodes, -0.76V), and the like, and are considered as ideal substitutes for next-generation energy storage batteries. However, the zinc cathode has problems of overgrowth of dendrite, hydrogen Evolution Reaction (HER), passivation of surface corrosion, poor stability of large current and the like, seriously influences the cycle life of the battery, and becomes a bottleneck for restricting AZIB further development and application. Up to now, many methods have been attempted to overcome the above problems faced by zinc anodes, mainly including modification of zinc anode host materials, construction of Artificial Solid Electrolyte Interfaces (ASEI), modification of separators, optimization of electrolytes, and the like. Among the numerous approaches, the construction of ASEI is becoming a research hotspot. This is mainly because zinc anode corrosion, HER and dendrite problems all occur at the electrolyte/electrode interface, and the construction of a protective coating between the electrolyte/electrode interface is an effective strategy to solve these problems. Studies have shown that by optimizing the protective coating composition and process, AZIB performance and cycle life are continually being refreshed. Based on the analysis, the beta-cyclodextrin modified polyion elastomer coating with the ion transmission and protection functions is constructed on the surface of the zinc negative electrode, and the hydrophobic interaction and the electrostatic interaction are combined to obtain the solvent-free transparent poly (ionic liquid) elastomer (PILE) coating system prepared by using the acrylate monomer and the ionic liquid to inhibit corrosion of the zinc negative electrode, HER and dendrite formation, and meanwhile, the beta-cyclodextrin is introduced to add a zinc ion diffusion channel in the polyion elastomer coating to promote planarization growth of the zinc dendrite and rapid desolventizing and diffusion of the zinc ion, so that the service life of the zinc negative electrode and the circulation stability under high current density are improved. Disclosure of Invention Aiming at the problems of overgrowth of dendrite, hydrogen evolution reaction, surface corrosion passivation, poor high-current stability and the like of a metal zinc cathode of a water system zinc ion battery in the charge and discharge process, the invention provides a preparation method for stabilizing the surface of the metal zinc cathode of a beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane. The process method is simple to prepare, environment-friendly, and capable of obtaining the interface layer with good adhesive force, high ion mobility and excellent dendrite inhibition performance, thereby realizing long-acting protection of the zinc cathode, improving the stability and service life of the zinc metal cathode in the circulating process of the water-based battery. Technical proposal In order to achieve the above purpose, the present invention is realized by the following technical scheme: The preparation method of the beta-cyclodextrin modified polyion elastomer copolymer electrolyte membrane stable metallic zinc anode surface specifically comprises the following steps: step 1, mixing lithium bistrifluoromethylsulfonylimide, acryloyloxyethyl trimethyl ammonium chloride and deionized water, and stirring the mixture; Step 2, washing and layering the stirred sample in the step 1, and enriching to obtain a lower ionic liquid; Step 3, placing the ionic liquid obtained in the step 2 in a vacuum oven for drying; step 4, mixing the ionic liquid dried in the step 3 with butyl acrylate and azodiisobutyronitrile, and sti