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CN-121983748-A - Halogenated Ti3C2Modified diaphragm material, preparation method and application thereof in potassium metal battery

CN121983748ACN 121983748 ACN121983748 ACN 121983748ACN-121983748-A

Abstract

The invention relates to the technical field of new energy electrochemistry, in particular to a Ti 3 C 2 halide modified diaphragm material, a preparation method and application thereof in a potassium metal battery, wherein a Ti 3 C 2 halide (also called MXene halide) material is selected to prepare slurry, the slurry is coated on one side of a commercial diaphragm Glass Fiber, and the diaphragm is dried in vacuum to obtain the potassium metal battery modified diaphragm. The modified diaphragm obtained by the method has high ionic conductivity and high mechanical strength, and the potassium ion battery taking the modified diaphragm as the diaphragm has the advantages of long cycle life, high stability and the like, and is beneficial to inhibiting the growth of potassium dendrites and stabilizing a potassium metal negative electrode. The full battery assembled by the battery has the advantages of high specific capacity, low cycle attenuation rate and the like, and is particularly and efficiently applicable to the field of new energy sources such as potassium metal batteries.

Inventors

  • JIANG YU
  • XU YUBO

Assignees

  • 安徽大学

Dates

Publication Date
20260505
Application Date
20260204

Claims (10)

  1. 1. The preparation method of the halogenated Ti 3 C 2 modified diaphragm material is characterized by comprising the following steps of: S1, grinding nickel halide, potassium halide and sodium halide to obtain mixed salt; S2, placing the mixed salt and Ti 3 AlC 2 obtained in the step S1 in an upper layer and a lower layer in a ceramic crucible, sintering in a muffle furnace, washing after sintering, carrying out suction filtration, and magnetically sucking out redundant metal; s3, freeze-drying the product treated in the step S2 to obtain dry halogenated Ti 3 C 2 ; S4, mixing halogenated Ti 3 C 2 with polyvinylidene fluoride and N-methyl pyrrolidone, and grinding to obtain slurry; And S5, coating the slurry modified in the step S4 on a glass fiber diaphragm, and drying to obtain the modified diaphragm of the halogenated Ti 3 C 2 .
  2. 2. The method for preparing a Ti 3 C 2 halide modified separator material according to claim 1, wherein in the step S1, the molar ratio of nickel halide, potassium halide and sodium halide is 3:5:5.
  3. 3. The method for preparing a halogenated Ti 3 C 2 modified membrane material according to claim 1, wherein in the step S2, the molar ratio of the mixed salt to Ti 3 AlC 2 is 1:13-1:52.
  4. 4. The method for preparing a Ti 3 C 2 halide modified membrane material according to claim 1, wherein in the step S2, the muffle furnace sintering temperature is 600-800 ℃ and the heat preservation time is 30min.
  5. 5. The method for preparing a Ti 3 C 2 halide modified separator material according to claim 1, wherein in the step S3, the Ti 3 C 2 halide is any one of Ti 3 C 2 bromide, ti 3 C 2 chloride and Ti 3 C 2 fluoride.
  6. 6. The method for preparing a Ti 3 C 2 halide modified separator material according to claim 1, wherein in the step S3, the freeze-drying temperature is-50 ℃ and the drying time is 15h.
  7. 7. The method for preparing the halogenated Ti 3 C 2 modified membrane material according to claim 1, wherein in the step S4, the mass ratio of halogenated Ti 3 C 2 to polyvinylidene fluoride is 7:1, and the weight-volume ratio of halogenated Ti 3 C 2 to N-methylpyrrolidone is 1 g:50-65 ml.
  8. 8. The method for preparing a Ti 3 C 2 halide modified separator material according to claim 1, wherein in the step S5, the temperature of the drying is 60 ℃.
  9. 9. A Ti 3 C 2 halide modified separator material produced by the production method according to any one of claims 1 to 8.
  10. 10. Use of the Ti 3 C 2 halide modified separator material of claim 9 in a potassium metal battery.

Description

Halogenated Ti 3C2 modified diaphragm material, preparation method and application thereof in potassium metal battery Technical Field The invention relates to the technical field of new energy electrochemistry, in particular to a halogenated Ti 3C2 modified diaphragm material, a preparation method and application thereof in a potassium metal battery. Background With the increasing demand of high energy density energy storage technology, especially in the field of electric automobiles, rechargeable batteries employing alkali metal anodes are increasingly under study. The natural abundance of potassium, as well as the low cost, further supports the utility of the scalable battery system. Based on these advantageous characteristics, potassium metal batteries are becoming a high energy density alternative or supplement to lithium batteries in a cost-effective and sustainable manner. Glass Fiber (GF) separators commonly used in potassium cells have inherent brittleness and insufficient mechanical strength, which lead to premature failure and shortened service life of the cells, and have serious problems such as lower conductivity, which are impediments to research and development of potassium cells. To enhance the conductivity and mechanical strength of the separator, thereby improving the lifetime of the K battery. Researchers use Al 2O3 and AlF3 to coat the separator to enhance the stability of the battery anode. These methods enhance the cycling of the cell to some extent, but the problems of low ionic conductivity and low strength of the glass fiber GF remain unsolved. In view of the above drawbacks, the present inventors have finally achieved the present invention through long-time studies and practices. Disclosure of Invention The invention aims to solve the problems that the inherent brittleness and insufficient mechanical strength of a Glass Fiber (GF) diaphragm commonly used in a potassium battery lead to premature failure of the battery and shortened service life and lower conductivity, and provides a Ti 3C2 halide modified diaphragm material, a preparation method and application thereof in a potassium metal battery. In order to achieve the above purpose, the invention discloses a preparation method of a halogenated Ti 3C2 modified diaphragm material, which comprises the following steps: S1, grinding nickel halide, potassium halide and sodium halide to obtain mixed salt; S2, placing the mixed salt and Ti 3AlC2 obtained in the step S1 in an upper layer and a lower layer in a ceramic crucible, sintering in a muffle furnace, washing after sintering, carrying out suction filtration, and magnetically sucking out redundant metal; S3, freeze-drying the product processed in the step S2 to obtain dried halogenated Ti 3C2 (also called halogenated MXene); S4, mixing halogenated Ti 3C2 with polyvinylidene fluoride and N-methyl pyrrolidone, and grinding to obtain slurry; And S5, coating the slurry modified in the step S4 on a glass fiber diaphragm, and drying to obtain the modified diaphragm of the halogenated Ti 3C2. In the step S1, the molar ratio of the nickel halide, the potassium halide and the sodium halide is 3:5:5. In the step S2, the molar ratio of the mixed salt to the Ti 3AlC2 is 1:13-1:52. In the step S2, the sintering temperature of the muffle furnace is 600-800 ℃ and the heat preservation time is 30min. In the step S3, the halogenated Ti 3C2 is any one of brominated Ti 3C2, chlorinated Ti 3C2, and fluorinated Ti 3C2. In the step S3, the freeze drying temperature is-50 ℃ and the drying time is 15h. In the step S4, the mass ratio of the halogenated Ti 3C2 to the polyvinylidene fluoride is 7:1, and the weight-volume ratio of the halogenated Ti 3C2 to the N-methylpyrrolidone is 1 g:50-65 mL. In the step S5, the temperature of the drying is 60 ℃. The invention also discloses a Ti-halide 3C2 modified diaphragm material prepared by the preparation method and application of the Ti-halide 3C2 modified diaphragm material in a potassium metal battery. Compared with the prior art, the invention has the beneficial effects that the MXene with a two-dimensional lamellar structure is selected, and the thickness of the coating layer is smaller, so that the whole thickness is not influenced. In addition, the addition of surface bromination greatly improves the ion conduction capacity and greatly improves the cycle performance of the battery. The method is environment-friendly, low in energy consumption and has great application potential. Drawings FIG. 1 is an XRD result of MXene bromide prepared in example 1 of the present invention; FIG. 2 is an SEM result of the brominated MXene prepared in example 1 of the invention; FIG. 3 is a photograph showing the thickness of a modified separator of MXene bromide prepared in example 1 of the present invention; FIG. 4 is a graph showing the tensile strength results of a modified diaphragm of MXene bromide obtained in example 1 of the present invention; FIG. 5 is a graph showing