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CN-121005385-B - Lithium ion solid electrolyte material yttrium lithium sodium phosphate and preparation method and application thereof

CN121005385BCN 121005385 BCN121005385 BCN 121005385BCN-121005385-B

Abstract

The invention relates to lithium ion solid electrolyte material yttrium lithium sodium phosphate, a preparation method and application thereof. The chemical formula of the lithium ion solid electrolyte material lithium yttrium lithium sodium phosphate is Li x Na 7‑ x Y 2 P 7 O 24 , wherein x=0-6.0, and preferably x=4.

Inventors

  • LIU JIANJUN
  • GUO YUANHANG
  • WANG YOUWEI

Assignees

  • 中国科学院上海硅酸盐研究所

Dates

Publication Date
20260512
Application Date
20250715

Claims (11)

  1. 1. A lithium ion solid electrolyte material yttrium lithium sodium phosphate, characterized in that the chemical formula of the lithium ion solid electrolyte material yttrium lithium sodium phosphate is Li x Na 7-x Y 2 P 7 O 24 , wherein x=0-6.0 and x is not 0.
  2. 2. The lithium ion solid state electrolyte material lithium yttrium sodium phosphate according to claim 1, wherein x = 4.
  3. 3. The lithium ion solid state electrolyte material lithium yttrium sodium phosphate according to claim 1, wherein the crystal structure of the lithium ion solid state electrolyte material lithium yttrium sodium phosphate belongs to monoclinic system, the space group is P2/c (No. 13), and the unit cell parameter is α=γ=90°, β=98-105 °.
  4. 4. A method for preparing lithium ion solid electrolyte material lithium yttrium sodium phosphate according to claim 1, comprising the following steps: (1) Weighing sodium salt, ammonium phosphate and yttrium oxide raw materials according to the stoichiometric ratio of the sodium yttrium phosphate Na 7 Y 2 P 7 O 24 , and mixing to obtain raw material mixed powder; (2) Presintering the raw material mixed powder, grinding, tabletting and calcining at high temperature again to obtain precursor powder; (3) And dissolving lithium salt in the ionic liquid, adding precursor powder, stirring, heating, reacting to perform ion replacement, washing, centrifuging and drying to obtain the lithium ion solid electrolyte material yttrium lithium sodium phosphate.
  5. 5. The method according to claim 4, wherein in the step (1), the sodium salt comprises at least one of sodium oxide, sodium carbonate, and sodium bicarbonate, and the ammonium phosphate salt comprises at least one of ammonium dihydrogen phosphate and ammonium dihydrogen phosphate.
  6. 6. The method according to claim 4, wherein in the step (2), the pre-firing temperature is 250-500 ℃, the heating rate is 2-10 ℃ per minute, and the holding time is 3-24 hours.
  7. 7. The process of claim 4, wherein in step (2), the tabletting is performed by uniaxial cold pressing or cold isostatic pressing at a pressure of 50 to 400MPa and a dwell time of 3 to 80min.
  8. 8. The method according to claim 4, wherein in the step (2), the high-temperature calcination is carried out at 550-650 ℃, the temperature rising rate is 2-10 ℃ per minute, and the heat preservation time is 8-36 hours.
  9. 9. The method according to claim 4, wherein in the step (3), the lithium salt comprises at least one of lithium bis (fluorosulfonyl) imide, lithium bis (difluoromethyl) sulfonyl imide, lithium bis (trifluoromethylsulfonyl) imide, and the ionic liquid comprises at least one of 1-butyl-3-methylimidazolium, 1-ethyl-2, 3-dimethylimidazolium, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide salt, and polyethylene glycol.
  10. 10. The method according to claim 4, wherein in the step (3), the molar ratio of the lithium salt to the ionic liquid is (1.5-2.5): 1, and the mass ratio of the mixed solution of the lithium salt and the ionic liquid to the precursor powder is (20-30): 1; the temperature of the stirring and heating reaction is 100-200 ℃, the time is 12-36h, and the rotating speed is 100-400rpm.
  11. 11. Use of the lithium ion solid state electrolyte material lithium yttrium sodium phosphate in accordance with claim 1 in a secondary battery, wherein the secondary battery comprises a lithium ion battery and a sodium ion battery.

Description

Lithium ion solid electrolyte material yttrium lithium sodium phosphate and preparation method and application thereof Technical Field The invention belongs to the technical field of battery electrolyte materials, and particularly relates to a lithium ion solid electrolyte material yttrium lithium sodium phosphate, a preparation method and application thereof. Background Lithium-ion power batteries with high energy density are becoming a research hotspot. The traditional battery uses an organic liquid electrolyte, has potential safety hazards such as fire and explosion, and has the advantages that the liquid electrolyte is replaced by a solid electrolyte with high safety, dendrite growth can be resisted, and the solid electrolyte is good in stability. The lithium ion solid electrolyte mainly includes an organic solid electrolyte, an oxide solid electrolyte, a sulfide solid electrolyte, and the like. The oxide solid electrolyte has a wide electrochemical window and chemical and electrochemical stability, but the oxide solid electrolyte has the problems of low ionic conductivity (less than 10 < -3 > S/cm) and the like, the conventional solid electrolyte material has been developed for a long time to approach the theoretical limit, and the breakthrough of the ionic conductivity also needs the discovery of a new structure. It was found that Na 7Y2P7O24, as a 30% one phase in a two-phase structure, is rich in monovalent ions, is a near-lamellar structure, has the potential to be a solid electrolyte, but cannot synthesize a pure phase such that performance cannot be measured and used. The low temperature liquid phase ion replacement method has been successfully demonstrated to have the ability to change a sodium ion conductor to a lithium ion conductor and can produce excellent performance. Disclosure of Invention Aiming at the problem of low ionic conductivity of the existing solid electrolyte of the lithium ion battery, the invention aims to provide a brand new frame yttrium lithium sodium phosphate material, and a preparation method and application thereof. When the material is used as a solid electrolyte, the material has bulk phase ion conductivity exceeding 10 < -3 > S/cm, and the method is simple and easy to implement. In a first aspect, the present invention provides a lithium ion solid state electrolyte material lithium yttrium sodium phosphate having the chemical formula Li xNa7-xY2P7O24, wherein x=0-6.0, preferably x=4. Preferably, the crystal structure of the lithium ion solid electrolyte material lithium yttrium sodium phosphate belongs to a monoclinic system, the space group is P2/c (No. 13), and the unit cell parameter is alpha=gamma=90 degrees and beta=98-105 degrees. In a second aspect, the invention provides a preparation method of the lithium ion solid electrolyte material yttrium lithium sodium phosphate, which comprises the following steps: (1) Weighing sodium salt, ammonium phosphate and yttrium oxide raw materials according to the stoichiometric ratio of the sodium yttrium phosphate Na 7Y2P7O24, and mixing to obtain raw material mixed powder; (2) Presintering the raw material mixed powder, grinding, tabletting and calcining at high temperature again to obtain precursor powder; (3) And dissolving lithium salt in the ionic liquid, adding precursor powder, stirring, heating, reacting to perform ion replacement, washing, centrifuging and drying to obtain the lithium ion solid electrolyte material yttrium lithium sodium phosphate. Preferably, in step (1), the sodium salt includes at least one of sodium oxide, sodium carbonate, and sodium bicarbonate, and the ammonium phosphate salt includes at least one of ammonium dihydrogen phosphate and ammonium dihydrogen phosphate. Preferably, in the step (2), the presintering temperature is 250-500 ℃, the heating rate is 2-10 ℃ per minute, and the heat preservation time is 3-24 hours. Preferably, in the step (2), the tabletting can adopt uniaxial cold pressing or cold isostatic pressing, the pressure is 50-400MPa, and the pressure maintaining time is 3-80min. Preferably, in the step (2), the high-temperature calcination temperature is 550-650 ℃, the heating rate is 2-10 ℃ per minute, and the heat preservation time is 8-36h. Preferably, in the step (3), the lithium salt comprises at least one of lithium bis (fluorosulfonyl) imide, lithium bis (difluoromethyl) imide, lithium bis (trifluoromethylsulfonyl) imide and lithium bis (trifluoromethylsulfonyl) imide, and the ionic liquid comprises at least one of 1-butyl-3-methylimidazolium, 1-ethyl-2, 3-dimethylimidazolium, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide salt and polyethylene glycol. Preferably, in the step (3), the molar ratio of the lithium salt to the ionic liquid is (1.5-2.5): 1, and the mass ratio of the mixed solution of the lithium salt and the ionic liquid to the precursor powder is (20-30): 1; Preferably, the temperature of the stirring and heating reaction is 100-200 ℃, the