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WO-2026091772-A1 - SUBMICRON SULFIDE SOLID ELECTROLYTE AND PREPARATION METHOD THEREFOR

WO2026091772A1WO 2026091772 A1WO2026091772 A1WO 2026091772A1WO-2026091772-A1

Abstract

A submicron sulfide solid electrolyte and a preparation method therefor. The preparation method comprises: weighing an appropriate amount of Li 2 S, P 2 S 5 , and LiX as starting materials, wherein X is a halogen element; mechanically milling the starting materials to obtain a sulfide solid electrolyte precursor; sintering the sulfide solid electrolyte precursor and cooling same at room temperature to obtain a large-particle-size sulfide solid electrolyte; and mechanically milling the large-particle-size sulfide solid electrolyte to obtain a submicron sulfide solid electrolyte. The submicron sulfide solid electrolyte is prepared by combining high-temperature solid-state sintering and mechanical milling, thereby effectively reducing starting material loss and improving starting material purity.

Inventors

  • ZHANG, HONGWU
  • LI, SIJIA
  • HE, Tete
  • PAN, XINGXING
  • LIU, YANG
  • PENG, CHAO

Assignees

  • 湖南恩捷前沿新材料科技有限公司

Dates

Publication Date
20260507
Application Date
20250813
Priority Date
20241028

Claims (15)

  1. A submicron-sized sulfide solid electrolyte, characterized by the chemical formula Li a P b S c X d , wherein a, b, c, and d represent the number of Li, P, S, and X elements respectively under the condition of one submicron-sized sulfide solid electrolyte, a, b, c, and d ensure that the submicron-sized sulfide solid electrolyte is electrically neutral, wherein X is a halogen element, and the particle size of the submicron-sized sulfide solid electrolyte is between 100 nm and 1 μm.
  2. According to claim 1, the submicron-scale sulfide solid electrolyte is characterized in that the halogen element is one or more of F, Cl, Br, and I.
  3. According to claim 1, the submicron-scale sulfide solid electrolyte is characterized in that a + 5b = 2c + d.
  4. According to claim 1, the submicron-scale sulfide solid electrolyte is characterized in that a = 5 to 6, b = 1, c = 4 to 5, and d = 1 to 2.
  5. The submicron-scale sulfide solid electrolyte according to claim 1 is characterized in that a = 5.5, b = 1, c = 4.5, d = 1.5; a = 6, b = 1, c = 5, d = 1; or a = 5.7, b = 1, c = 4.7, d = 1.3.
  6. A method for preparing a submicron-sized sulfide solid electrolyte, characterized by comprising: Weigh appropriate amounts of Li₂S , P₂S₅ and LiX as raw materials, wherein X is a halogen element; The raw material is mechanically ground to obtain a sulfide solid electrolyte precursor; The sulfide solid electrolyte precursor was sintered and cooled to room temperature to obtain a large-particle-size sulfide solid electrolyte; and The large-particle-size sulfide solid electrolyte is mechanically ground to obtain a submicron-sized sulfide solid electrolyte.
  7. The method for preparing submicron-scale sulfide solid electrolyte according to claim 6 is characterized in that the halogen element is one or more of F, Cl, Br, and I.
  8. The method for preparing submicron-scale sulfide solid electrolyte according to claim 6 is characterized in that the raw materials further include metal salts, wherein the metal salts include one or more of Fe, Zn, Ge, Zr, Ca, Mg, Ti, and Ag.
  9. The method for preparing submicron-sized sulfide solid electrolyte according to claim 6 is characterized in that the mechanical grinding of the raw material is carried out in a high-speed mixer, a planetary ball mill, a horizontal ball mill, or an air jet mill.
  10. The method for preparing submicron-scale sulfide solid electrolyte according to claim 6 is characterized in that, when mechanically grinding the raw material, the pressure inside the ball mill is 800 Pa to 1000 Pa, the ball-to-material ratio is (20 to 60): 1, the ball milling speed is 10 r/min to 50 r/min, and the ball milling time is 2 h to 4 h.
  11. The method for preparing submicron-scale sulfide solid electrolyte according to claim 6 is characterized in that the sintering temperature is 400℃ to 500℃ and the sintering time is 2h to 4h.
  12. The method for preparing submicron-sized sulfide solid electrolyte according to claim 6 is characterized in that, when mechanically grinding the large-particle-size sulfide solid electrolyte, the ball-to-material ratio is (20 to 60):1, the liquid-to-material ratio is 1:(20 to 60), the ball milling speed is 100 r/min to 2800 r/min, and the ball milling time is 0.5 h to 4 h.
  13. The method for preparing submicron-sized sulfide solid electrolyte according to claim 6 is characterized in that the large-particle-size sulfide solid electrolyte is mechanically ground in a ball milling solvent, wherein the ball milling solvent includes one or more of cyclohexane, xylene, o-xylene, methyl xylene, n-heptane, dimethyl carbonate, and isobutyl isobutyrate.
  14. The method for preparing submicron-sized sulfide solid electrolyte according to claim 6 is characterized in that the raw material is mechanically ground by dry ball milling, and the large-particle-size sulfide solid electrolyte is mechanically ground by wet ball milling.
  15. The method for preparing submicron-scale sulfide solid electrolyte according to claim 6 is characterized in that the molar ratio between Li₂S , P₂S₅ and LiX is (2 to 6): 1: (2 to 4).

Description

Submicron-sized sulfide solid electrolyte and its preparation method Technical Field This invention relates to the technical field of sulfide solid electrolytes, and specifically to a submicron-scale sulfide solid electrolyte and its preparation method. Background Technology All-solid-state batteries have attracted much attention due to their high safety and higher energy density. Solid-state electrolytes, as key materials in all-solid-state batteries, directly affect the cycle performance of these batteries through their ionic conductivity, interfacial contact, and electrochemical stability. Sulfide solid-state electrolytes, with their excellent ionic conductivity and good interfacial contact, have become a research hotspot among inorganic solid-state electrolytes. Currently, the main methods for preparing sulfide solid electrolytes are dry ball milling and wet ball milling. Dry ball milling produces sulfide solid electrolyte particles with larger sizes, requiring further processing. Wet ball milling produces smaller particles, but suffers from decreased ionic conductivity and poorer performance. Doping with halogen elements can improve the electrochemical stability of the electrolyte, enhance its stability in contact with the positive and negative electrodes, and improve the safety and stability of all-solid-state batteries. Currently, the amount of sulfide electrolytes prepared in the laboratory is small, thus affecting large-scale production. Therefore, developing new processes for the mass production of sulfide solid electrolytes is one of the challenges. Summary of the Invention The purpose of this invention is to propose a submicron-scale sulfide solid electrolyte and its preparation method, which can improve the safety and stability of batteries, increase the mass production capacity of submicron-scale sulfide electrolytes, and provide assistance for the industrialization of all-solid-state batteries. The present invention is implemented as follows: a submicron-sized sulfide solid electrolyte, represented by the chemical formula Li a P b S c X d , wherein a, b, c, and d represent the number of Li, P, S, and X elements under the condition of one submicron-sized sulfide solid electrolyte, respectively, and a, b, c, and d ensure that the submicron-sized sulfide solid electrolyte is electrically neutral, wherein X is a halogen element, and the particle size of the submicron-sized sulfide solid electrolyte is between 100 nm and 1 μm. For example, the halogen element is one or more of F, Cl, Br, and I. For example, a + 5b = 2c + d. For example, a = 5 to 6, b = 1, c = 4 to 5, d = 1 to 2. For example, a = 5.5, b = 1, c = 4.5, d = 1.5; a = 6, b = 1, c = 5, d = 1; or a = 5.7, b = 1, c = 4.7, d = 1.3. The present invention is implemented as follows: a method for preparing a submicron-sized sulfide solid electrolyte, comprising: weighing appropriate amounts of Li₂S , P₂S₅ , and LiX as raw materials, wherein X is a halogen element; mechanically grinding the raw materials to obtain a sulfide solid electrolyte precursor; sintering the sulfide solid electrolyte precursor and cooling it at room temperature to obtain a large-particle-size sulfide solid electrolyte; and mechanically grinding the large-particle-size sulfide solid electrolyte to obtain a submicron-sized sulfide solid electrolyte. For example, the halogen element is one or more of F, Cl, Br, and I. For example, the raw material further includes metal salts, which include one or more of Fe, Zn, Ge, Zr, Ca, Mg, Ti, and Ag. For example, the mechanical grinding of the raw material is carried out in a high-speed mixer, a planetary ball mill, a horizontal ball mill, or an air jet mill. For example, when mechanically grinding the raw material, the pressure inside the ball mill is 800 Pa to 1000 Pa, the ball-to-material ratio is (20 to 60): 1, the ball mill speed is 10 r/min to 50 r/min, and the ball milling time is 2 h to 4 h. For example, the sintering temperature is 400°C to 500°C, and the sintering time is 2 hours to 4 hours. For example, when mechanically grinding the large-particle-size sulfide solid electrolyte, the ball-to-material ratio is (20 to 60):1, the liquid-to-material ratio is 1:(20 to 60), the ball milling speed is 100 r/min to 2800 r/min, and the ball milling time is 0.5 h to 4 h. For example, the large-particle-size sulfide solid electrolyte is mechanically milled in a ball milling solvent, which includes one or more of cyclohexane, xylene, o-xylene, methyl xylene, n-heptane, dimethyl carbonate, and isobutyl isobutyrate. For example, the raw material is mechanically ground using dry ball milling, and the large-particle-size sulfide solid electrolyte is mechanically ground using wet ball milling. For example, the molar ratio between Li₂S , P₂S₅ and LiX is (2 to 6): 1: (2 to 4). Based on the above solutions, this invention proposes a sulfide solid electrolyte and its preparation method, taking into account the properties of sulfide electrolytes