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CN-121976357-A - Skeleton membrane, composite solid electrolyte membrane, preparation method of composite solid electrolyte membrane, battery and power utilization device

CN121976357ACN 121976357 ACN121976357 ACN 121976357ACN-121976357-A

Abstract

The application belongs to the technical field of batteries, and in particular relates to a skeleton membrane, a composite solid electrolyte membrane, a preparation method of the skeleton membrane, a battery and an electric device, wherein the skeleton membrane comprises organic fibers, the organic fibers comprise first fibers with an orientation angle of 0-15 degrees, and the orientation angle is an acute included angle between the length direction of the organic fibers and the thickness direction of the skeleton membrane; the quantity of the first fibers in the organic fibers is 60% -100%. The skeleton membrane has higher mechanical property.

Inventors

  • WU QIHANG
  • TANG CHENGYU

Assignees

  • 比亚迪股份有限公司

Dates

Publication Date
20260505
Application Date
20251209

Claims (15)

  1. 1. A skeletal membrane, comprising: The organic fiber comprises first fibers with an orientation angle of 0-15 degrees, wherein the orientation angle is an acute angle included angle between the length direction of the organic fiber and the thickness direction of the skeleton membrane, and the quantity of the first fibers in the organic fiber accounts for 60-100%.
  2. 2. The skeletal film of claim 1, wherein the first fibers are present in an amount of 80% to 100% of all of the organic fibers.
  3. 3. The skeletal film of claim 1 or 2, wherein the organic fibers comprise a polymer comprising at least one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trifluoroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, polyethylene oxide, polyvinyl alcohol, polyacrylonitrile, polyimide, polyvinylpyrrolidone, and cellulose.
  4. 4. A matrix film according to claim 3 wherein the organic fibres further comprise a lithium salt and at least one of the following conditions is met: The lithium salt comprises at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethanesulfonyl) imide and lithium nitrate; The mass ratio of the polymer to the lithium salt is 5-30:0.01-15.
  5. 5. The skeletal film of any one of claims 1 to 4, wherein the organic fibers have a diameter of 0.01 μm to 10 μm.
  6. 6. A composite solid electrolyte membrane comprising: The skeletal membrane of any one of claims 1 to 5; an inorganic electrolyte matrix filled in the gaps between the organic fibers in the skeletal film.
  7. 7. The composite solid electrolyte membrane of claim 6 wherein the inorganic electrolyte matrix comprises an inorganic electrolyte that satisfies at least one of the following conditions: The inorganic electrolyte comprises at least one of an oxide electrolyte and a sulfide electrolyte, preferably at least one of lithium aluminum titanium phosphate, lithium lanthanum zirconium oxide, LGPS and Li 6 PS 5 X, wherein X is at least one of Cl, br and I; The inorganic electrolyte matrix further comprises a binder, wherein the binder comprises at least one of polyvinylidene fluoride, polyethylene oxide, polyvinyl alcohol, polyacrylonitrile and hydrogenated nitrile rubber, and/or the mass ratio of the binder to the inorganic electrolyte is 0.1-5:10-60.
  8. 8. The composite solid electrolyte membrane according to claim 6 or 7, wherein the thickness of the composite solid electrolyte membrane is 10 μm to 200 μm.
  9. 9. A method of preparing the skeletal film of any one of claims 1-5, comprising: Mixing an organic fiber raw material with a first solvent to obtain a spinning solution; And carrying out electrostatic spinning on the spinning solution, and collecting to obtain a skeleton membrane, wherein the organic fiber is collected and simultaneously a shearing force is applied to the organic fiber.
  10. 10. The method according to claim 9, wherein the method of collecting the skeletal membrane comprises any one of a high-speed rotation collection method, a high-speed air-flow auxiliary method, a parallel electrode collection method, a magnetic field auxiliary collection method, preferably any one of the high-speed rotation collection method and the magnetic field auxiliary collection method.
  11. 11. The method of claim 10, wherein at least one of the following conditions is satisfied: In the high-speed rotation collection method, the rotation speed of a collector is 1000 rpm-5000 rpm; The first solvent comprises at least one of water, N-dimethylformamide, N-methylpyrrolidone, acetone, acetonitrile, dichloromethane, chloroform, methanol, ethanol, formic acid, acetic acid and tetrahydrofuran; The spinning solution comprises a polymer, lithium salt and the first solvent, wherein the mass ratio of the polymer to the lithium salt is 5-30:0.01-15:55-95.
  12. 12. A method of preparing the composite solid electrolyte membrane of any one of claims 6 to 8, comprising: preparing a skeletal film by the method of any one of claims 9 to 11; Mixing an inorganic electrolyte matrix raw material with a second solvent to obtain an inorganic slurry; And coating the inorganic slurry on the cross section of the skeleton membrane, enabling the inorganic slurry to permeate into gaps among the organic fibers, and drying to obtain the composite solid electrolyte membrane.
  13. 13. The method of claim 12, wherein at least one of the following conditions is satisfied: The second solvent comprises at least one of water, N-dimethylformamide, N-methylpyrrolidone, acetone, acetonitrile, dichloromethane, chloroform, methanol, ethanol, formic acid, acetic acid, tetrahydrofuran and anisole; The inorganic slurry comprises a binder, an inorganic electrolyte and the second solvent in a mass ratio of 0.1-5:10-60:40-90.
  14. 14. A battery comprising the composite solid electrolyte membrane according to any one of claims 6 to 8 or the composite solid electrolyte membrane produced by the method according to claim 12 or 13.
  15. 15. An electrical device comprising the composite solid electrolyte membrane according to any one of claims 6 to 8, the composite solid electrolyte membrane produced by the method according to claim 12 or 13, or the battery according to claim 14.

Description

Skeleton membrane, composite solid electrolyte membrane, preparation method of composite solid electrolyte membrane, battery and power utilization device Technical Field The application relates to the technical field of batteries, in particular to a skeleton membrane, a composite solid electrolyte membrane, a preparation method of the skeleton membrane and the composite solid electrolyte membrane, a battery and an electric device. Background The solid-state battery has potential advantages in all aspects of safety, energy density, power density and the like by adopting the solid-state electrolyte with high ion conductivity to replace the existing liquid electrolyte, and is expected to greatly improve the competitiveness of the power battery in the aspects of long circulation, quick charge and the like. As a key component in the solid-state battery, solid-state electrolytes are mainly classified into inorganic electrolytes (oxides, sulfides, halides, and the like), polymer electrolytes, and composite electrolytes. The common composite electrolyte consists of flexible polymer electrolyte and rigid inorganic electrolyte, balances the performances of the two electrolytes and is expected to realize industrial application. It has been proposed to collect oriented composite fiber bundles by using an inorganic electrolyte and an organic polymer as spinning materials through a high-speed drum, obtain inorganic electrolyte fiber bundles after calcination, and fill the molten polymer between the inorganic electrolyte fiber bundles to obtain a composite solid electrolyte membrane. However, this method requires high temperature calcination to remove the polymer, which is cumbersome and wasteful of material. Accordingly, the solid electrolyte related art has yet to be improved. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, the invention provides the skeleton membrane, the composite solid electrolyte membrane and the preparation method thereof, the battery and the power utilization device, and the skeleton membrane has the advantages of simple preparation method, lower cost or mechanical property and ion transmission property. In a first aspect of the application, a skeletal membrane is provided. According to the embodiment of the application, the skeleton membrane comprises organic fibers, wherein the organic fibers comprise first fibers with an orientation angle of 0-15 degrees, the orientation angle is an acute included angle between the length direction of the organic fibers and the thickness direction of the skeleton membrane, and the quantity of the first fibers in the organic fibers is 60-100%. The skeleton membrane has the advantages that the organic fibers are arranged in a highly oriented mode, so that the skeleton membrane can be used for effectively supporting stress in a synergic mode, and the mechanical strength is high. Meanwhile, the organic fibers which are arranged in an oriented way can form a straight-through hole structure, so that a shorter and more direct transmission path is provided for active ions, the ion transmission resistance is effectively reduced, and the higher ion conductivity is obtained. According to the embodiment of the application, the number of the first fibers in all the organic fibers is 80% -100%. According to an embodiment of the present application, the organic fiber includes a polymer including at least one of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trifluoroethylene, polyvinylidene fluoride-chlorotrifluoroethylene, polyethylene oxide, polyvinyl alcohol, polyacrylonitrile, polyimide, polyvinylpyrrolidone, and cellulose. According to an embodiment of the application, the organic fiber further comprises a lithium salt. The lithium salt comprises at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium bis (fluorosulfonyl) imide, lithium bis (trifluoromethanesulfonyl) imide and lithium nitrate. According to the embodiment of the application, the mass ratio of the polymer to the lithium salt is 5-30:0.01-15. According to the embodiment of the application, the diameter of the organic fiber is 0.01-10 mu m. In a second aspect of the present application, a composite solid electrolyte membrane is provided. According to an embodiment of the present application, the composite solid electrolyte membrane includes the skeletal membrane described previously, and an inorganic electrolyte matrix filled in the interstices between the organic fibers in the skeletal membrane. The composite solid electrolyte membrane has the advantages that the organic fibers are arranged in a highly oriented mode, so that the stress can be effectively and cooperatively borne, and the mechanical strength is high. Meanwhile, the organic fibers which are arranged in an oriented way can form a straight-through hole structu