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CN-122000276-A - Preparation method of high-entropy MXene modified lithium metal anode based on solution coating

CN122000276ACN 122000276 ACN122000276 ACN 122000276ACN-122000276-A

Abstract

The invention discloses a preparation method of a high-entropy MXene modified lithium metal negative electrode based on solution coating, which belongs to the technical field of lithium metal battery electrode materials, and comprises the steps of adding a high-entropy MAX material into hydrofluoric acid solution, etching and stripping Al to obtain a high-entropy MXene single-layer solution, and then obtaining high-entropy MXene powder through vacuum freeze drying; dissolving high-entropy MXene powder in an N-methylpyrrolidone solvent to prepare a solution of 80mg/ml, and adding 5% of a pvdf solution as a binder to prepare a mixed solution; the three-dimensional multi-layer high-active-site composite electrode prepared by the method can remarkably improve the capacity of a battery and prolong the cycle life.

Inventors

  • JIA SONGYU
  • SUN JIAN
  • LIU RUJING

Assignees

  • 成都大学

Dates

Publication Date
20260508
Application Date
20260211

Claims (9)

  1. 1. The preparation method of the high-entropy MXene modified lithium metal anode based on solution coating is characterized by comprising the following steps of: S1, adding a high-entropy MAX material into a hydrofluoric acid solution, stirring at a constant temperature, then centrifugally washing until the material is neutral to obtain a high-entropy MXene dispersion liquid, and performing vacuum freeze drying to obtain high-entropy MXene powder A; s2, dissolving the powder A into an N-methyl pyrrolidone solvent and adding a PVDF binder to prepare a mixed solution A; And S3, dripping the mixed solution A on a lithium sheet by using a liquid-transferring gun, and drying in vacuum to obtain the electrode containing the protective layer.
  2. 2. The method for preparing the solution-coated high-entropy MXene-modified lithium metal negative electrode according to claim 1, wherein the high-entropy MAX material in S1 is MXene precursor powder containing five elements and more, and the mass is 1-3 g.
  3. 3. The preparation method of the solution-coated high-entropy MXene-modified lithium metal negative electrode is characterized in that the mass fraction of hydrofluoric acid in the S1 is 20% -60% and the volume is 20-60 mL.
  4. 4. The preparation method of the solution-coated high-entropy MXene-modified lithium metal negative electrode according to claim 1, wherein the constant-temperature stirring temperature in the step S1 is 20-30 ℃ and the constant-temperature stirring time is 36-48 h.
  5. 5. The method for preparing the high-entropy MXene modified lithium metal anode based on the solution coating according to claim 1, wherein the concentration of powder A in the mixed solution A in the step S2 is 60-100 mg/ml.
  6. 6. The method for preparing the high-entropy MXene modified lithium metal anode based on the solution coating according to claim 1, wherein the volume fraction of PVDF in the mixed solution A in the step S2 is 5%.
  7. 7. The method for preparing the solution-coated high-entropy MXene-modified lithium metal negative electrode according to claim 1, wherein the dropping operation in the step S3 is performed at a concentration of 0.3-0.5 ml/cm 2 .
  8. 8. The preparation method of the solution-coated high-entropy MXene-modified lithium metal negative electrode according to claim 1-7, wherein the drying mode in the step S3 is 30-40 ℃ and vacuum drying is carried out for 24-48 h.
  9. 9. The high-entropy MXene modified lithium metal anode material based on solution coating obtained by the preparation method according to any one of claims 1-8 is applied to a lithium metal battery anode.

Description

Preparation method of high-entropy MXene modified lithium metal anode based on solution coating Technical Field The invention belongs to the technical field of lithium metal battery electrode materials, and particularly relates to a preparation method of a high-entropy MXene modified lithium metal negative electrode based on solution coating. Background The high-entropy MXene is a novel functional material combining a two-dimensional material and a high-entropy alloy concept, and is formed by five or more transition metal elements in equimolar or nearly equimolar proportions to form a stable crystal structure with maximum configurational entropy, and common representative materials include TiVNbMoC and the like. The material inherits the excellent conductivity, the adjustable surface property and the ion intercalation capability of the traditional MXene, generates a lattice distortion effect, a slow diffusion effect and a cocktail effect by virtue of the high entropy property, and shows unique advantages in the field of electrochemical energy. 3Tx、TiVCrMoC3Tx The lithium metal battery can obviously promote the endurance of the electric automobile (up to more than 800 km) and support quick charge (for example, 12 minutes to 70 percent) due to the high energy density (theoretical capacity is up to mAh/g, which is 10 times of that of a graphite cathode), and is regarded as the key direction of the next-generation battery technology. The development scale is rapid, and the market prospect is wide. The lithium metal battery cathode technology still faces key challenges such as poor interface stability, dendrite growth, short cycle life, volume expansion in the charge and discharge process, and the like. Although the existing MXene modification layer can improve the lithium deposition behavior, the single transition metal composition of the existing MXene modification layer limits the further improvement of the performance, and particularly the effect of inhibiting the volume change is not satisfactory. Specifically, patent CN114512660a proposes a preparation method of an MXene/polymer composite modification layer, but the technology has obvious limitations that firstly, the surface chemical characteristics of the traditional MXene (such as Ti) are single, the guiding effect on lithium ions is limited, secondly, the polymer matrix may obstruct the rapid transmission of ions and electrons, furthermore, the method has limited effect in inhibiting the volume expansion in the charging and discharging process of the lithium metal anode, and furthermore, the preparation process needs to precisely control the reaction conditions of the monomer and the initiator, and the process complexity is higher. 3C2Tx Therefore, there is a need for an electrode material that is simple to operate, ensures uniform deposition of lithium ions, effectively suppresses volume expansion, and ensures battery performance, and a method for preparing the same. Disclosure of Invention In order to solve the problems, the invention provides a preparation method of a high-entropy MXene modified lithium metal anode based on solution coating. The preparation method of the high-entropy MXene modified lithium metal anode based on solution coating is characterized by comprising the following steps of: S1, adding a high-entropy MAX material into a hydrofluoric acid solution, stirring at a constant temperature, then centrifugally washing until the material is neutral to obtain a high-entropy MXene dispersion liquid, and performing vacuum freeze drying to obtain high-entropy MXene powder A; s2, dissolving the powder A into an N-methyl pyrrolidone solvent and adding a PVDF binder to prepare a mixed solution A; And S3, dripping the mixed solution A on a lithium sheet by using a liquid-transferring gun, and drying in vacuum to obtain the electrode containing the protective layer. Further, the high-entropy MAX material in the S1 is TiVCrMoAlC 3 or TiVNbMoAlC 3, and the mass is 1-3 g. Further, the mass fraction of hydrofluoric acid in the step S1 is 20% -60%, and the volume is 20-60 mL. Further, the constant-temperature stirring temperature in the step S1 is 20-30 ℃ and the constant-temperature stirring time is 36-48 h. Further, in the mixed solution B in the step S2, the concentration of the powder A is 60-100 mg/ml. Further, in the mixed solution B in S2, the volume fraction of PVDF is 5%. Further, the dripping operation in the step S3 is performed at a concentration of 0.3-0.5 ml/cm 2. Further, the drying mode in the step S3 is 30-40 ℃ vacuum drying for 24-48 hours. The high-entropy MXene modified lithium metal anode material based on solution coating, which is prepared by the method, is also in the protection scope of the invention. Compared with the prior art, the invention has the following advantages: (1) The high-entropy MXene material used in the invention has a unique layered structure and excellent mechanical elasticity, can well adapt to huge volume