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CN-122025520-A - Preparation method and application of foliate ZIF-L/MXene composite material

CN122025520ACN 122025520 ACN122025520 ACN 122025520ACN-122025520-A

Abstract

The invention relates to the technical field of water-based zinc ion batteries, in particular to a preparation method and application of a foliated ZIF-L/MXene composite material. The preparation method comprises the steps of stirring and mixing a MXene suspension and zinc salt to obtain a mixed solution, and stirring and reacting the mixed solution and 2-methylimidazole to enable the leaf-shaped ZIF-L to uniformly and vertically grow on the surface of the MXene to obtain the leaf-shaped ZIF-L/MXene composite material. The method has simple process and mild reaction conditions, and the obtained composite material has the porous structure of the leaf-shaped ZIF-L and the conductive characteristic of MXene, so that the iodine loading capacity and the electrochemical performance of the anode of the zinc-iodine battery can be effectively improved.

Inventors

  • LingHu Yaoyao
  • YUAN KAI
  • MA JING
  • QU YONGPING
  • ZHOU RUI
  • GAO HUI

Assignees

  • 中北大学

Dates

Publication Date
20260512
Application Date
20260225

Claims (8)

  1. 1. The preparation method of the foliate ZIF-L/MXene composite material is characterized by comprising the following steps: Stirring and mixing the MXene suspension and zinc salt to directionally enrich and fix Zn 2+ on the surface of MXene to obtain a mixed solution, and stirring and reacting the mixed solution with 2-methylimidazole to vertically grow the foliate ZIF-L on the surface of MXene to obtain the foliate ZIF-L/MXene composite material.
  2. 2. The preparation method of the foliated ZIF-L/MXene composite material according to claim 1, wherein the mass ratio of MXene to 2-methylimidazole is 1:10-30, and the molar ratio of zinc salt to 2-methylimidazole is 1:6-10.
  3. 3. The preparation method of the foliated ZIF-L/MXene composite material according to claim 1, wherein the specific operation of stirring the mixed solution and 2-methylimidazole is that stirring is carried out for 25-30 min at a rotating speed of 200r/min +/-10 r/min, and stirring is carried out for 1h at a rotating speed of 300r/min +/-10 r/min.
  4. 4. The preparation method of the foliated ZIF-L/MXene composite material according to claim 1, wherein the suspension of MXene is a mixture of MXene and water, and the mass ratio of MXene to water is 1:5-20.
  5. 5. The preparation method of the foliated ZIF-L/MXene composite material according to claim 1, wherein the specific operation of stirring and mixing the suspension of MXene and the zinc salt is that stirring is carried out for 30min at a rotating speed of 100r/min +/-10 r/min at 20-30 ℃.
  6. 6. The method of preparing a foliated ZIF-L/MXene composite material of claim 1 wherein the MXene suspension is one or more of Ti 3 C 2 T x 、Nb 2 CT x 、Mo 2 CT x 、Ti 4 N 3 .
  7. 7. The method of preparing a foliated ZIF-L/MXene composite material according to claim 1, wherein the zinc salt is one or more of Zn(NO 3 ) 2 •6H 2 O、ZnSO 4 •7H 2 O、Zn(CH 3 COO) 2 •2H 2 O、ZnCl 2 .
  8. 8. Use of a foliated ZIF-L/MXene composite material prepared by the preparation method of any one of claims 1 to 7 as a carrier material in the preparation of an anode of a water-based zinc-iodine battery.

Description

Preparation method and application of foliate ZIF-L/MXene composite material Technical Field The invention relates to the technical field of water-based zinc ion batteries, in particular to a preparation method and application of a foliated ZIF-L/MXene composite material. Background The Aqueous Zinc Ion Battery (AZIBs) has the characteristics of low oxidation-reduction potential [ -0.76V (vs. SHE) ], low cost, high capacity (820 mAhj. G −1), superior safety and the like, and is considered as one of the most potential energy storage systems. Iodine is used as one of the positive electrode materials of the water-based zinc ion battery, and has the advantages of rich storage (the iodine content in the ocean reaches 50-60 mug L −1), relatively high specific capacity (211 mAh is equal to g −1), good cycle stability, environmental protection and no harm, and is also attractive to a large number of researchers. However, aqueous zinc-iodine batteries face challenges of poor conductivity, self-discharge, slow reaction kinetics, low energy density, and insufficient stability of the zinc anode. To address these problems, the construction of a carrier material for an iodine positive electrode is a popular and effective strategy aimed at solving the problem that iodine and its multi-iodide intermediate products are easily dissolved in electrolyte and shuttle effect. Therefore, there is an urgent need to design a carrier material with excellent conductivity and strong adsorption capacity to load iodine, so as to significantly improve the conductivity and stability of the positive electrode. ZIF-L (L-shaped layered zeolite imidazole ester skeleton) in metal organic frame Materials (MOFs) has a two-dimensional morphology, a regular pore structure and good molecular sieving performance, and is widely focused in the fields of separation membranes, catalysis, electrochemical energy storage and the like. MXene is used as a two-dimensional layered carbonitride material, has excellent conductivity and mechanical stability, and can effectively improve the conductivity and structural stability of ZIF-L by compounding the MXene with the ZIF-L, thereby expanding the application of the MXene in the field of electrochemical energy storage. At present, a common ZIF-L and MXene compounding method is a solution mixing method, such as documents Applied Surface Science, 2023 and 625: 157194, and reports that a composite material is obtained by dispersing ZIF-L and MXene in a specific solvent, realizing preliminary mixing by means of stirring, ultrasonic treatment and the like, and carrying out steps of suction filtration and the like. However, the method has the problems of uneven compounding and weak interfacial binding force, and is easy to cause unstable performance of the composite material. Disclosure of Invention In order to solve the problems, the invention provides a preparation method and application of a foliate ZIF-L/MXene composite material. The preparation method changes from physical mixing to chemical anchoring and in-situ growth, and the invention directionally enriches and fixes Zn 2+ on the surface of MXene through the strong interaction of the MXene surface functional group and Zn 2+, and then directionally grows the leaf-shaped ZIF-L on the surface of MXene through the coordination reaction of 2-methylimidazole and Zn 2+ to form the composite material with a porous structure and high conductivity. The process replaces the traditional physical adsorption by chemical bonding, and obviously enhances the interfacial binding force, so that the problems of uneven compounding and weak interfacial binding are solved, and the performance stability of the material in a zinc-iodine battery is improved. The preparation method has simple process and mild reaction conditions, and the obtained composite material has the porous structure of the leaf-shaped ZIF-L and the conductive characteristic of MXene, and can effectively improve the iodine loading capacity and the electrochemical performance of the anode of the zinc-iodine battery when being applied to the zinc-iodine battery. In order to achieve the above object, the technical scheme of the present invention is as follows. The invention provides a preparation method of a foliate ZIF-L/MXene composite material, which comprises the following steps: Stirring and mixing the MXene suspension and zinc salt to obtain a mixed solution, and stirring and reacting the mixed solution and 2-methylimidazole to uniformly grow the foliated ZIF-L on the surface of the MXene to obtain the foliated ZIF-L/MXene composite material. Preferably, the mass ratio of MXene to 2-methylimidazole is 1:10-30, and the molar ratio of zinc salt to 2-methylimidazole is 1:6-10. The ratio of MXene to ligand mainly controls the shape and coverage rate of ZIF-L, too low ratio leads to the formation of an agglomeration body instead of a leaf-shaped structure by excessive nucleation of ZIF-L, too high ratio leads to the