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CN-122010565-A - Oxyhalide solid electrolyte material, and preparation method and application thereof

CN122010565ACN 122010565 ACN122010565 ACN 122010565ACN-122010565-A

Abstract

The invention relates to the technical field of solid-state batteries, in particular to an oxyhalide solid-state electrolyte material, a preparation method and application thereof. The oxyhalide solid electrolyte provided by the invention is an oxyhalide with coexistent crystalline and amorphous states, and the molecular formula is Li 3+ x VO x Cl 6‑x , wherein x is more than 0 and less than or equal to 2. The ratio of crystalline state to amorphous state in the oxyhalide solid electrolyte material can be accurately regulated and controlled by utilizing multi-step control, so that the optimal crystal structure is obtained.

Inventors

  • YANG RUIZHI
  • LIU YIHAO

Assignees

  • 苏州大学

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The preparation method of the oxyhalide solid electrolyte material is characterized by comprising the following steps of: s11, adding LiCl organic dispersion liquid, li 2 O organic dispersion liquid and VCl 3 organic dispersion liquid into ethyl acetate in a protective atmosphere, and reacting at 50-100 ℃ for 2-8 h to obtain a reacted dispersion liquid, wherein the amount of ethyl acetate is kept unchanged during the reaction; s12, spray drying the reacted dispersion liquid at 180-260 ℃, tabletting and joule heat synthesis to obtain a ceramic sheet; and S13, grinding, tabletting and annealing the ceramic sheet in a protective atmosphere to obtain the oxyhalide solid electrolyte material, wherein the molecular formula of the oxyhalide solid electrolyte material is Li 3+x VO x Cl 6-x , and x is more than 0 and less than or equal to 2.
  2. 2. The method of claim 1, wherein the solvent in the LiCl organic dispersion, the Li 2 O organic dispersion and the VCl 3 organic dispersion is toluene or xylene.
  3. 3. The method of claim 1, wherein the LiCl concentration in the LiCl organic dispersion is 2-5 mol/L, the Li 2 O concentration in the Li 2 O organic dispersion is 1-3 mol/L, and the VCl 3 concentration in the VCl 3 organic dispersion is 1-5 mol/L.
  4. 4. The method according to claim 1, wherein the volume ratio of the LiCl organic dispersion, the Li 2 O organic dispersion, the VCl 3 organic dispersion and the ethyl acetate is 1:1-2:1-2:4-6.
  5. 5. The method of claim 1, wherein in the step S11, the organic dispersion is added into ethyl acetate by a microfluidic method, the flow rate of LiCl organic dispersion is 1-20 μL/min, the concentration of Li 2 O organic dispersion is 10-15 μL/min, and the concentration of VCl 3 organic dispersion is 5-10 μL/min.
  6. 6. The method of claim 1, wherein the Joule heating is performed at a current of 8-12A for 30-150S.
  7. 7. The method according to claim 1, wherein the spray-drying feed rate in the step S12 is 100-500 mL/h.
  8. 8. The method of claim 1, wherein the annealing temperature is 200-800 ℃ and the annealing time is 3-15 h in step S13.
  9. 9. An oxyhalide solid electrolyte material prepared by the preparation method of any one of claims 1 to 8.
  10. 10. An all-solid-state lithium battery, characterized in that the electrolyte of the all-solid-state lithium battery is the oxyhalide solid-state electrolyte material as claimed in claim 9.

Description

Oxyhalide solid electrolyte material, and preparation method and application thereof Technical Field The invention relates to the technical field of solid-state batteries, in particular to an oxyhalide solid-state electrolyte material, a preparation method and application thereof. Background All-solid-state lithium batteries are one of the candidates for the next generation battery system with great competitiveness because of their high energy density, long cycle life and high safety. The core of developing the high-performance all-solid-state lithium battery is to prepare a solid electrolyte material with high lithium ion conductivity at room temperature, wide electrochemical stability window and good compatibility with an electrode/electrolyte interface. At present, research on inorganic solid electrolyte materials mainly includes oxide-type, sulfide-type and halide-type solid electrolytes. The oxide type solid electrolyte has good electrochemical stability, but the rigid lattice thereof leads to poor electrode/electrolyte interface contact, and is accompanied by low lithium ion conductivity and high grain boundary impedance, thus being not suitable for high-power density all-solid lithium batteries. Sulfide-type solid state electrolytes have room temperature lithium ion conductivities that are comparable to or even exceed those of liquid electrolytes, but their limited electrochemical stability and structural and interfacial instability are short plates that limit their further development. The halide type solid electrolyte can achieve both oxidation resistance of oxide and high ion conductivity and mechanical ductility of sulfide, has simple preparation process, does not need harsh environment and extremely high sintering temperature, and has great potential in high-performance all-solid-state lithium battery application. The conventional halide still has the problem of insufficient ion conductivity, and oxygen doping induction material amorphization is usually carried out to prepare oxyhalide so as to improve the ion conductivity, such as a recently reported Li 1.2TaO1.2Cl3.8 oxyhalide solid electrolyte (J. Phys. Chem. Lett. 2025, 16, 8283-8289) with the ion conductivity of 9 mS cm -1 at room temperature. However, this method is effective only for a part of specific halides, and has been reported (ChemSusChem 2025,00, e 202500495), whereas for high crystallinity halides, oxygen doping decreases the room temperature ionic conductivity. Disclosure of Invention Therefore, the invention aims to solve the technical problem of insufficient ion conductivity in the prior art, and can accurately regulate and control the ratio of crystalline state to amorphous state in oxyhalide solid electrolyte material by utilizing multi-step control to obtain an optimal crystal structure. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The invention provides a preparation method of oxyhalide solid electrolyte material, which comprises the following steps: S11, adding LiCl organic dispersion liquid, li 2 O organic dispersion liquid and VCl 3 organic dispersion liquid into ethyl acetate in a protective atmosphere, and reacting at 50-100 ℃ for 2-8 h to obtain a reacted dispersion liquid, wherein the volume of the ethyl acetate is kept unchanged during the reaction; s12, spray-drying the reacted dispersion liquid at 180-260 ℃, tabletting and performing Joule thermal synthesis to obtain a ceramic sheet; and S13, grinding, tabletting and annealing the ceramic sheet in a protective atmosphere to obtain the oxyhalide solid electrolyte material, wherein the molecular formula of the oxyhalide solid electrolyte material is Li 3+xVOxCl6-x, and x is more than 0 and less than or equal to 2. The oxyhalide solid electrolyte material is an oxyhalide with coexistent crystalline and amorphous states. Preferably, the solvents in the LiCl organic dispersion, li 2 O organic dispersion, and VCl 3 organic dispersion are all toluene or xylene. Xylene is poorly miscible with ethyl acetate and is prone to forming "water-in-oil" type emulsion droplets. Preferably, the protective atmospheres are all argon. Preferably, the LiCl concentration in the LiCl organic dispersion is 2-5 mol/L, the Li 2 O concentration in the Li 2 O organic dispersion is 1-3 mol/L, and the VCl 3 concentration in the VCl 3 organic dispersion is 1-5 mol/L. Preferably, the molar ratio of LiCl, li 2 O, and VCl 3 is 2:1:1. Preferably, the volume ratio of the LiCl organic dispersion, the Li 2 O organic dispersion, the VCl 3 organic dispersion, and the ethyl acetate is 1:1:1:4-6. The temperature of the ethyl acetate is controlled to be 50-100 ℃, and the ethyl acetate is continuously replenished along with the evaporation of the ethyl acetate, and the liquid phase reaction is carried out for 2-8 h in the device after the ethyl acetate is added dropwise. Preferably, in the step S11, the organic dispersion liquid is added into ethyl aceta