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EP-4738507-A1 - SOLID ELECTROLYTE MEMBRANE AND PREPARATION METHOD AND APPLICATION THEREOF

EP4738507A1EP 4738507 A1EP4738507 A1EP 4738507A1EP-4738507-A1

Abstract

The invention provides a solid electrolyte membrane and a preparation method and application thereof, wherein the solid electrolyte membrane includes a binder; and a sulfide solid electrolyte, and a molecular formula of the sulfide solid electrolyte is Li a P 1-b M b S c O d X e ; wherein 5<a<6, 0<b<1, 1.5<c<5, 0<d<2.5, 4<c+d<5, 1<e<2; M is selected from one or a plurality of Al, Ga, In, Ti, Sc, As, Sb, Bi, As, V, or Nb; X is selected from one or a plurality of Cl, Br, or I; and an ionic conductivity of the solid electrolyte membrane is 1×10 -3 S/cm to 2×10 -2 S/cm. The invention provides a solid electrolyte membrane and a preparation method and application thereof to improve the stability of the conductivity of the solid electrolyte membrane, enhance air stability, improve electrolyte/active material interface properties, and improve the life and the safety of the all-solid-state lithium-ion battery.

Inventors

  • YU, LE
  • WU, MING

Assignees

  • AESC Japan Ltd.

Dates

Publication Date
20260506
Application Date
20250822

Claims (11)

  1. A solid electrolyte membrane, at least comprising: a binder; and a sulfide solid electrolyte, wherein a molecular formula of the sulfide solid electrolyte is Li a P 1-b M b S c O d X e ; wherein 5<a<6, 0<b<1, 1.5<c<5, 0<d<2.5, 4<c+d<5, 1<e<2; M is selected from one or a plurality of Al, Ga, In, Ti, Sc, As, Sb, Bi, V, or Nb; X is selected from one or a plurality of Cl, Br, or I; an ionic conductivity of the solid electrolyte membrane is 1×10 -3 S/cm to 2×10 -2 S/cm.
  2. The solid electrolyte membrane of claim 1, wherein M is one or a plurality of Sb, In, or Bi.
  3. The solid electrolyte membrane of claim 1, wherein X is Cl; and a value range of b is 0<b≤0.1.
  4. The solid electrolyte membrane of claim 1, wherein a thickness of the solid electrolyte membrane is 1 µm to 200 µm.
  5. The solid electrolyte membrane of claim 1, wherein a mass ratio of the binder to the sulfide solid electrolyte is 0.1:99.9 to 10:90.
  6. A preparation method of the solid electrolyte membrane of claim 1, comprising steps of: mixing raw materials evenly according to a stoichiometric amount and placing in a ball mill for ball milling according to a chemical formula of a sulfide solid electrolyte to obtain a sulfide solid electrolyte precursor powder; calcining the sulfide solid electrolyte precursor powder at a preset temperature to obtain the sulfide solid electrolyte; and mixing the sulfide solid electrolyte with a binder, and the solid electrolyte membrane is prepared by a dry method or a wet method.
  7. The preparation method of the solid electrolyte membrane of claim 6, wherein the raw materials comprise a Li source, a P source, an M source, a S source, and an X source, the Li source is selected from one or a plurality of LiCl, LiBr, LiI, or Li 2 S; the P source is selected from one or a plurality of elemental P, P 2 S 5 , P 4 S 6 , PCl 5 , or PBr 5 ; the M source is selected from one or a plurality of an oxide of M or a sulfide of M; the S source is selected from one or a plurality of elemental S, Li 2 S, P 2 S 5 , P 4 S 6 , As 2 S 5 , As 2 S 3 , Sb 2 S 5 , Sb 2 S 3 , Bi 2 S 5 , Bi 2 S 3 , Ga 2 S 3 , In 2 S 3 , or Sc 2 S 3 ; the X source is selected from one or a plurality of LiCl, PCl 5 , LiBr, PBr 5 , LiI, or I 2 ; the O element in the chemical formula comes from the oxide of M.
  8. The preparation method of the solid electrolyte membrane of claim 6, wherein when the solid electrolyte membrane is prepared by the dry method, the binder is selected from a first binder, and the first binder is selected from one or a plurality of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, fluorinated ethylene-propylene copolymer, perfluoroalkoxy resin, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, or polyvinylidene fluoride-chlorotrifluoroethylene copolymer.
  9. The preparation method of the solid electrolyte membrane of claim 6, wherein when the solid electrolyte membrane is prepared by the wet method, the binder is selected from a second binder, and the second binder is selected from one or a plurality of polyvinylidene fluoride, carboxymethyl cellulose, styrene-butadiene rubber, polyvinyl pyrrolidone, polymethyl methacrylate, polyacrylonitrile, polyacrylic acid, polyurethane, polyvinyl alcohol, sodium alginate, ethylene-propylene-diene monomer, styrene-butadiene rubber, fluororubber, β -cyclodextrin polymer, polypropylene emulsion, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, fluorinated ethylene-propylene copolymer, perfluoroalkoxy resin, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride-hexafluoropropylene copolymer, or polyvinylidene fluoride-chlorotrifluoroethylene copolymer.
  10. An all-solid-state lithium-ion battery, at least comprising: a positive electrode sheet, wherein the positive electrode sheet comprises a halide solid electrolyte, wherein the halide solid electrolyte comprises Li 2.35 Zr 0.65 Fe 0.35 Cl 5 Br 0.5 I 0.5 ; a negative electrode sheet; and a solid electrolyte membrane, wherein the solid electrolyte membrane is disposed between the adjacent positive electrode sheet and the negative electrode sheet, and the solid electrolyte membrane is selected from the solid electrolyte membrane of any of claims 1 to 5.
  11. An electronic apparatus, comprising the all-solid-state lithium-ion battery of claim 10.

Description

BACKGROUND OF THE INVENTION Field of the Invention The invention relates to the technical field of lithium-ion batteries, and in particular to a solid electrolyte membrane and a preparation method and application thereof. Description of Related Art At present, lithium-ion batteries are widely used in fields such as portable electronic apparatus, electric vehicles, and energy storage systems. However, traditional lithium-ion batteries use flammable organic liquid electrolytes, which have the drawbacks of safety risks and lower energy density, thus limiting the further development thereof. All-solid-state lithium batteries use solid electrolytes instead of liquid electrolytes, have higher safety, wider operating temperature range, and higher energy density, and are an important development direction of the next generation of battery techniques. Sulfide solid electrolytes have become one of the most promising electrolyte materials of all-solid-state lithium batteries due to the high ionic conductivity and good mechanical properties thereof. However, most sulfide electrolytes are readily decomposed in the air to generate toxic hydrogen sulfide gas, and the production conditions are strict, thus increasing the complexity and the cost of production. In addition, sulfide electrolytes have worse compatibility with lithium metal negative electrodes, and are prone to interfacial reactions, inducing the formation of lithium dendrites and causing battery short circuits. SUMMARY OF THE INVENTION The invention provides a solid electrolyte membrane and a preparation method and application thereof. The solid electrolyte membrane and the preparation method and application thereof provided by the invention may improve the stability of the electrical conductivity of the solid electrolyte membrane, enhance air stability, improve electrolyte/active material interface properties, and improve the life and the safety of the all-solid-state lithium-ion battery. In order to solve the above technical issues, the invention provides a solid electrolyte membrane, at least including: a binder; anda sulfide solid electrolyte, wherein a molecular formula of the sulfide solid electrolyte is LiaP1-bMbScOdXe; wherein 5<a<6, 0<b<1, 1.5<c<5, 0<d<2.5, 4<c+d<5, 1<e<2; M is selected from one or a plurality of Al, Ga, In, Ti, Sc, As, Sb, Bi, As, V, or Nb; X is selected from one or a plurality of Cl, Br, or I;an ionic conductivity of the solid electrolyte membrane is 1×10-3 S/cm to 2×10-2 S/cm. In an embodiment of the invention, M is one or a plurality of Sb, In, or Bi. In an embodiment of the invention, X is Cl; a value range of b is 0<b≤0.1. In an embodiment of the invention, a thickness of the solid electrolyte membrane is 1 µm to 200 µm. In an embodiment of the invention, a mass ratio of the binder to the sulfide solid electrolyte is 0.1:99.9 to 10:90. The invention also provides a preparation method of the above solid electrolyte membrane, including steps of: mixing raw materials evenly according to a stoichiometric amount, and then placing in a ball mill for ball milling according to a chemical formula of a sulfide solid electrolyte to obtain a sulfide solid electrolyte precursor powder;calcining the sulfide solid electrolyte precursor powder at a preset temperature to obtain the sulfide solid electrolyte; andmixing the sulfide solid electrolyte with a binder, and the solid electrolyte membrane is prepared by a dry method or prepared by a wet method. In an embodiment of the invention, the raw materials include a Li source, a P source, an M source, a S source, and an X source, the Li source is selected from one or a plurality of LiCl, LiBr, LiI, or Li2S; the P source is selected from one or a plurality of elemental P, P2S5, P4S6, PCl5, or PBr5; the M source is selected from one or a plurality of an oxide of M or a sulfide of M; the S source is selected from one or a plurality of elemental S, Li2S, P2S5, P4S6, As2S5, As2S3, Sb2S5, Sb2S3, Bi2S5, Bi2S3, Al2S3, Ga2S3, In2S3, or Sc2S3 ; the X source is selected from one or a plurality of LiCl, PCl5, LiBr, PBr5, LiI, or I2; the O element in the chemical formula comes from the oxide of M. In an embodiment of the invention, when the solid electrolyte membrane is prepared by the dry method, the binder is selected from a first binder, and the first binder is selected from one or several of polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, fluorinated ethylene-propylene copolymer, perfluoroalkoxy resin, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, or polyvinylidene fluoride-chlorotrifluoroethylene copolymer. In an embodiment of the invention, when the solid electrolyte membrane is prepared by the wet method, the binder is selected from a second binder, and the second binder is selected from one or a plurality of polyvinylidene fluoride, carboxymethyl cellulose, styrene-butadiene rubbe