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CN-122000481-A - Preparation method of low-temperature oxidation-dynamic sintering nano LATP

CN122000481ACN 122000481 ACN122000481 ACN 122000481ACN-122000481-A

Abstract

The invention relates to the technical field of materials, and particularly discloses a preparation method of low-temperature oxidation-dynamic sintering nanometer LATP, which comprises the following steps of S1, mixing a lithium source, an aluminum source, a titanium source and a phosphorus source according to the stoichiometric ratio of LATP, adding at least one of a boron-containing glass phase forming agent or a doping modifier containing lanthanide to prepare a modified precursor mixture, S2, carrying out sectional low-temperature oxidation heat treatment on the modified precursor mixture in an oxygen-containing atmosphere to obtain pre-oxidized powder, and S3, carrying out dynamic sintering treatment on the pre-oxidized powder to obtain a modified nanocrystalline LATP solid electrolyte material.

Inventors

  • ZHAN WEIDONG
  • CHAI XIAODONG
  • Zhan Xinya

Assignees

  • 浙江东太新材料有限公司

Dates

Publication Date
20260508
Application Date
20260211

Claims (9)

  1. 1. The preparation method of the low-temperature oxidation-dynamic sintering nano LATP is characterized by comprising the following steps of: s1, mixing a lithium source, an aluminum source, a titanium source and a phosphorus source according to a LATP stoichiometric ratio, and adding at least one of a boron-containing glass phase forming agent or a doping modifier containing lanthanide to prepare a modified precursor mixture; s2, carrying out sectional low-temperature oxidation heat treatment on the modified precursor mixture in an oxygen-containing atmosphere to obtain pre-oxidized powder; S3, carrying out dynamic sintering treatment on the pre-oxidized powder to obtain the modified nano-crystal LATP solid electrolyte material.
  2. 2. The method for preparing low-temperature oxidation-dynamic sintering nano LATP according to claim 1, wherein the boron-containing glass phase forming agent is at least one of boric acid, boron oxide and lithium borate, and the addition amount of the boron-containing glass phase forming agent is 0.1-5wt.% of the theoretical mass fraction of LATP.
  3. 3. The method of claim 1, wherein the doping modifier is at least one of lanthanum oxide, cerium oxide, and yttrium oxide, and the addition amount of the doping modifier is 0.1-5at.% Ti sites in LATP.
  4. 4. The method for preparing low-temperature oxidation-dynamic sintering nano LATP according to claim 1, wherein in the step S1, the boron-containing glass phase forming agent is added by dissolving the boron-containing glass phase forming agent in an organic solvent to form a solution, and then uniformly mixing the solution with the mixture of the lithium source, the aluminum source, the titanium source and the phosphorus source.
  5. 5. The preparation method of low-temperature oxidation-dynamic sintering nano LATP according to claim 1, wherein the step S2 of the segmented low-temperature oxidation heat treatment specifically comprises: The first stage, namely preserving heat for 1-5 hours at 300-450 ℃; and in the second stage, the temperature is kept at 500-650 ℃ for 2-8 hours, wherein a gaseous precursor of the doping modifier containing the lanthanide is introduced in the temperature rising process of the second stage for gas-phase auxiliary doping.
  6. 6. The method of claim 1 wherein the gaseous precursor is at least one of an acetylacetonate, a cyclopentadienyl compound, or a halide of a lanthanide.
  7. 7. The method for preparing the low-temperature oxidation-dynamic sintering nano LATP according to claim 1, wherein the dynamic sintering treatment in the step S3 adopts spark plasma sintering, the technological parameters are that the sintering temperature is 700-900 ℃, the sintering pressure is 30-100 MPa, the heat preservation time is 5-30 minutes, and a strong magnetic field of 0.1-10T is added while pulse current is applied in the sintering process.
  8. 8. The method of claim 1, wherein the strong magnetic field has a magnetic field strength of 1-5T and is perpendicular to or forms a specific angle with the direction of the pulse current.
  9. 9. The method of preparing low temperature oxidation-dynamic sintering nano LATP according to claim 1, wherein in the step S3, 0.01-2wt.% of two-dimensional nano material is added to the pre-oxidized powder before dynamic sintering as grain boundary reinforcing agent, wherein the two-dimensional nano material comprises but is not limited to hexagonal boron nitride nano-sheets, transition metal carbonitride MXene or graphene nano-sheets.

Description

Preparation method of low-temperature oxidation-dynamic sintering nano LATP Technical Field The invention belongs to the technical field of materials, and particularly relates to a preparation method of low-temperature oxidation-dynamic sintering nanometer LATP. Background The solid electrolyte is a core component of the next generation of high-safety and high-energy density all-solid lithium batteries. Among them, lithium aluminum titanium phosphate materials based on NASICON structure are attracting attention due to their high room temperature ion conductivity, excellent air stability and wide electrochemical window. Currently, the preparation of LATP materials mainly relies on a high temperature solid phase reaction method, i.e. by mechanically mixing precursors such as lithium source, aluminum source, titanium source and phosphorus source, followed by sintering at high temperature (typically higher than 900 ℃) for a long time to complete the solid phase diffusion reaction and obtain a dense ceramic body, and in addition, wet chemical methods such as sol-gel method, coprecipitation method are used to improve the uniformity of the precursors, but they still finally need to undergo a high temperature sintering step to achieve crystallization and densification of the materials. However, the above-described existing preparation method is extremely prone to abnormal coarsening of LATP grains during sintering at high temperature and for a long time, forming micrometer-sized or even larger grains, which not only reduces the effective ion transport interface, but may introduce more grain boundary defects. Secondly, the high temperature environment aggravates the reduction tendency of titanium, and the impurity phases such as low-valence titanium oxide are easy to generate, so that the uniformity and stability of the crystal structure are damaged, and the ion conductivity is damaged. Disclosure of Invention The invention aims to provide a preparation method of low-temperature oxidation-dynamic sintering nanometer LATP, which aims to solve the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: A preparation method of low-temperature oxidation-dynamic sintering nanometer LATP comprises the following steps: s1, mixing a lithium source, an aluminum source, a titanium source and a phosphorus source according to a LATP stoichiometric ratio, and adding at least one of a boron-containing glass phase forming agent or a doping modifier containing lanthanide to prepare a modified precursor mixture; s2, carrying out sectional low-temperature oxidation heat treatment on the modified precursor mixture in an oxygen-containing atmosphere to obtain pre-oxidized powder; S3, carrying out dynamic sintering treatment on the pre-oxidized powder to obtain the modified nano-crystal LATP solid electrolyte material. Preferably, the boron-containing glass phase forming agent is at least one of boric acid, boron oxide and lithium borate, and the addition amount of the boron-containing glass phase forming agent is 0.1-5wt.% of the theoretical mass fraction of LATP. Preferably, the doping modifier containing lanthanide is at least one of lanthanum oxide, cerium oxide and yttrium oxide, and the addition amount of the doping modifier is 0.1-5at.% Ti site in the LATP. Preferably, in the step S1, the boron-containing glass phase forming agent is added by dissolving the boron-containing glass phase forming agent in an organic solvent to form a solution, and then uniformly mixing the solution with the mixture of the lithium source, the aluminum source, the titanium source and the phosphorus source. Preferably, the step S2 of the staged low temperature oxidation heat treatment specifically includes: The first stage, namely preserving heat for 1-5 hours at 300-450 ℃; and in the second stage, the temperature is kept at 500-650 ℃ for 2-8 hours, wherein a gaseous precursor of the doping modifier containing the lanthanide is introduced in the temperature rising process of the second stage for gas-phase auxiliary doping. Preferably, the gaseous precursor is at least one of an acetylacetonate, a cyclopentadienyl compound or a halide of the lanthanide series. Preferably, the dynamic sintering treatment in the step S3 adopts spark plasma sintering, wherein the process parameters are that the sintering temperature is 700-900 ℃, the sintering pressure is 30-100 MPa, the heat preservation time is 5-30 minutes, and a strong magnetic field of 0.1-10T is added while pulse current is applied in the sintering process. Preferably, the direction of the strong magnetic field is perpendicular to the direction of the pulse current or forms a specific included angle, and the magnetic field strength is 1-5T. Preferably, in the step S3, 0.01-2wt.% of a two-dimensional nanomaterial including, but not limited to, hexagonal boron nitride nanoplatelets, transition metal carbonitride MXe