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CN-122000272-A - Silane modified zinc anode material grafted with covalent organic framework protective coating and preparation method and application thereof

CN122000272ACN 122000272 ACN122000272 ACN 122000272ACN-122000272-A

Abstract

The disclosure provides a silane modified zinc anode material grafted with a covalent organic framework protective coating, and a preparation method and application thereof. The preparation method comprises the steps of adding zinc foil into pretreatment liquid of ethanol-water mixed solution dissolved with alkyl chain extender, adding silane coupling agent after reaction, continuing reaction, washing and drying to obtain silane modified zinc cathode, adding the silane modified zinc cathode into reaction solution dissolved with aldehyde monomer and amine monomer for reaction, washing, soxhlet extraction and drying to obtain the silane modified zinc cathode material grafted with covalent organic framework protective coating. The silane modified zinc anode material has the advantages of strong interfacial binding force, high ion transmission efficiency, excellent dendrite inhibition effect, simple and controllable process, easily available raw materials, suitability for large-scale production, excellent cycle stability and electrochemical performance, and is applied to a water-based zinc ion battery, thereby providing key material support for the industrialization of high-performance water-based zinc ion batteries.

Inventors

  • XU YONGJIE
  • GAO JIANBO
  • Qu Dianyi
  • LI CHENGGANG
  • ZHANG LIULIU
  • CHEN PU

Assignees

  • 宁波数字孪生(东方理工)研究院

Dates

Publication Date
20260508
Application Date
20251222

Claims (10)

  1. 1. The preparation method of the silane modified zinc anode material grafted with the covalent organic framework protective coating is characterized by comprising the following steps of: S1, adding zinc foil into pretreatment liquid of ethanol-water mixed solution dissolved with alkyl chain extender, adding silane coupling agent after reaction, continuing reaction, washing and drying to obtain silane modified zinc foil substrate; S2, adding the silane modified zinc foil substrate into a reaction solution in which aldehyde monomers and amine monomers are dissolved, reacting for 12-120 hours at 25-180 ℃, washing, soxhlet extraction and drying to obtain the silane modified zinc anode material grafted with the covalent organic framework protective coating.
  2. 2. The preparation method of claim 1, wherein in the step S1, the mass ratio of the alkyl chain extender to the zinc foil is 1:0.01-1:100; Preferably, the mass ratio of the alkyl chain extender to the silane coupling agent is 1:0.001-1:10.
  3. 3. The preparation method according to claim 1, wherein in the step S1, the alkyl chain extender is at least one of tetraethyl silicate and tetrabutyl titanate, and the silane coupling agent is at least one of silane containing amino, epoxy, vinyl and mercapto functional groups; Preferably, the silane coupling agent is 3-aminopropyl triethoxysilane or 3-glycidoxy propyl trimethoxysilane.
  4. 4. The method according to claim 1, wherein in the step S1, the reaction is performed at 25 to 35 ℃ for 1 to 2 hours, and the continuous reaction is performed for 4 to 6 hours.
  5. 5. The preparation method according to claim 1, wherein in the step S2, the molar ratio of the aldehyde monomer to the amine monomer is 1:0.1-1:10; Preferably, the aldehyde monomer is 1,3, 5-trimethyl phloroglucinol or 1,3, 5-trialdehyde benzene, and the amine monomer is 2, 5-diaminobenzene sulfonic acid or p-phenylenediamine; more preferably, the aldehyde monomer is 1,3, 5-trimethyl phloroglucinol and the amine monomer is 2, 5-diaminobenzene sulfonic acid.
  6. 6. The method according to claim 1, wherein in step S2, the solvent of the reaction solution is a mixed solvent of 1, 4-dioxane and mesitylene or dimethyl sulfoxide; Preferably, the washing is repeated washing with ethanol and N, N-dimethylformamide; more preferably, the Soxhlet extraction is carried out for 12-48 hours by using methanol and tetrahydrofuran respectively; Most preferably, the drying is performed at 50-70 ℃ for 8-16 hours.
  7. 7. The method according to claim 1, wherein in step S1, the zinc foil is polished zinc foil after polishing and ultrasonic cleaning.
  8. 8. The silane modified zinc anode material grafted with covalent organic framework protective coating prepared by the preparation method of any one of claims 1-7.
  9. 9. Use of the silane modified zinc anode material of claim 8 to improve the performance of a battery.
  10. 10. The water-based zinc ion battery is characterized in that the water-based zinc ion battery is assembled by taking the silane modified zinc anode material as the anode material, manganese dioxide, vanadium pentoxide or Prussian blue analogues as the cathode material, taking aqueous solution of zinc sulfate and manganese sulfate as electrolyte and glass fiber as a diaphragm.

Description

Silane modified zinc anode material grafted with covalent organic framework protective coating and preparation method and application thereof Technical Field The disclosure relates to the technical field of preparation of cathodes of zinc ion batteries, in particular to a silane modified zinc cathode material grafted with a covalent organic framework protective coating, and a preparation method and application thereof. Background The water-based zinc ion battery has the advantages of low cost (low price of electrolyte raw materials), environmental friendliness (no pollution risk of the electrolyte), high safety (no hidden danger of explosion) and the like due to the adoption of water-soluble electrolyte (such as ZnSO 4 aqueous solution), and is considered to be an ideal candidate battery system in the fields of large-scale energy storage, portable electronic equipment and the like. The metal zinc cathode is the first-choice cathode material of the water-based zinc ion battery because of high theoretical capacity (820 mAh/g), low electrode potential (-0.76V vs standard hydrogen electrode), and abundant earth resource reserves (about 70 mg/kg of zinc crust abundance). However, zinc cathode has three major core problems in practical application, namely, the zinc cathode has serious restriction on the performance and service life, namely, firstly, zinc dendrite growth problems are that irregular dendrites are easily formed due to uneven surface electric field distribution when zinc ions are deposited on the surface of the cathode, a diaphragm is easily pierced in the dendrite growth process, so that the internal short circuit of the battery is caused, the safety risk is caused, meanwhile, dendrite falling can cause active material loss, the battery capacity is reduced, secondly, severe side reactions are caused, namely, when the zinc cathode is directly contacted with an aqueous electrolyte, hydrogen evolution reaction (2H 2O + 2e-→ H2↑ + 2OH-) and surface corrosion reaction are easily caused, a loose ZnO/Zn (OH) 2 passivation layer is generated, and the side reactions not only lead to the fluctuation of the pH value of the electrolyte and the loss of the active material, but also reduce the coulomb efficiency of the battery (the coulomb efficiency of the traditional zinc cathode is always lower than 85 percent), thirdly, the problem of poor interface stability is that the traditional zinc cathode has no effective protection layer on the surface, the electrode-electrolyte interface is easily damaged in the charge-discharge process, so that polarization is increased, and the rate performance and the cycling stability of the battery are reduced. In order to solve the problems, scientific researchers develop various modification strategies such as electrode surface coating, electrolyte additive introduction, diaphragm modification and the like. The Covalent Organic Frameworks (COFs) material is an ideal zinc anode protective coating matrix because of a highly ordered porous structure (the pore diameter is adjustable within the range of 1-5 nm), excellent chemical stability (acid-base resistance and water-resistant electrolyte corrosion resistance) and a smooth ion transmission channel. However, the existing COFs material has the defect that the bonding force between the COFs framework and the surface of the zinc anode is weak (only by physical adsorption), and the COFs framework is easy to fall off in the charge and discharge process. Therefore, a method for grafting a covalent organic framework protective coating on the surface of a zinc anode material through a strong covalent bond is developed, the problem of incompatibility of an organic-inorganic composite interface is fundamentally solved, and the problems of dendrite, side reaction, interface stability and the like of a zinc anode are further effectively solved, so that the method has important significance for development of a water-based zinc ion battery. Disclosure of Invention The present disclosure provides a silane modified zinc anode material grafted with a Covalent Organic Framework (COFs) protective coating, and a preparation method and application thereof, so as to at least solve the above technical problems in the prior art. According to a first aspect of the present disclosure, there is provided a method for preparing a silane modified zinc anode material grafted with a Covalent Organic Framework (COFs) protective coating, comprising the steps of: S1, adding zinc foil into pretreatment liquid of ethanol-water mixed solution dissolved with alkyl chain extender, adding silane coupling agent after reaction, continuing reaction, washing and drying to obtain silane modified zinc foil substrate; S2, adding the silane modified zinc foil substrate into a reaction solution in which aldehyde monomers and amine monomers are dissolved, reacting for 12-120 hours at 25-180 ℃, washing, soxhlet extraction and drying to obtain the silane modified zinc anode mate