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CN-122025750-A - Composite solid electrolyte membrane with three-dimensional network structure and preparation method thereof

CN122025750ACN 122025750 ACN122025750 ACN 122025750ACN-122025750-A

Abstract

The invention discloses a composite solid electrolyte membrane with a three-dimensional network structure and a preparation method thereof, wherein the preparation method comprises (1) immersing a silicon wafer into polystyrene microsphere emulsion, and obtaining a SiO 2 inverse opal template through deposition and calcination; the preparation method comprises the steps of (1) adding an SiO 2 inverse opal template into an oxide solid electrolyte precursor solution for infiltration, drying and calcining to obtain an oxide/SiO 2 composite skeleton, (3) removing an SiO 2 template in the oxide/SiO 2 composite skeleton, washing and drying the SiO 2 -removed composite skeleton, immersing the SiO 2 -removed composite skeleton into a silane hydrolysate for reaction, washing and drying to obtain a three-dimensional oxide solid electrolyte skeleton with surface modified-OH groups, and (4) immersing the three-dimensional oxide solid electrolyte skeleton with surface modified-OH groups into the polymer electrolyte precursor solution for infiltration, drying and solidifying to obtain the composite solid electrolyte membrane with a three-dimensional network structure. The composite solid electrolyte membrane can improve the ionic conductivity and the cycle performance.

Inventors

  • LIANG PING
  • YANG HUIMIN
  • AN HONGLI
  • SONG RANRAN
  • LIU GUIJUAN
  • JIANG ZHICHENG
  • JIN ZHAOXING
  • Li Mianqian

Assignees

  • 北京新能源汽车股份有限公司
  • 北京新能源汽车股份有限公司蓝谷动力系统分公司

Dates

Publication Date
20260512
Application Date
20260323

Claims (10)

  1. 1. The preparation method of the composite solid electrolyte membrane with the three-dimensional network structure is characterized by comprising the following steps: (1) Immersing a silicon wafer into polystyrene microsphere emulsion, and obtaining a SiO 2 inverse opal template through deposition and calcination; (2) Adding the SiO 2 inverse opal template into oxide solid electrolyte precursor liquid for infiltration, and then drying and calcining to obtain an oxide/SiO 2 composite framework; (3) Removing SiO 2 template in the oxide/SiO 2 composite framework, washing and drying the composite framework with SiO 2 removed, immersing the composite framework in silane hydrolysate for reaction, and finally washing and drying to obtain the three-dimensional oxide solid electrolyte framework with surface modified-OH groups; (4) Immersing the three-dimensional oxide solid electrolyte skeleton with the surface modified-OH group into polymer electrolyte precursor liquid for infiltration, and then drying and solidifying to obtain the composite solid electrolyte membrane with the three-dimensional network structure.
  2. 2. The preparation method of claim 1, wherein in the step (1), the polystyrene microsphere emulsion is prepared by a method comprising the steps of adding a styrene monomer, an initiator and an emulsifier into water, and stirring to obtain the polystyrene microsphere emulsion; Preferably, the initiator is at least one of potassium persulfate, ammonium persulfate, azodiisobutyronitrile and dibenzoyl peroxide, the emulsifier is at least one of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, polyvinylpyrrolidone and cetyltrimethylammonium bromide, and the content of the styrene monomer is 20-40wt%, the content of the initiator is 0.5-1wt%, the content of the emulsifier is 0.2-3wt% and the balance is water based on the total weight of the styrene monomer, the initiator, the emulsifier and the water.
  3. 3. The method according to claim 1, wherein in the step (1), the deposition temperature is 20 to 40 ℃, the relative humidity is 30 to 60%, and the deposition time is 6 to 24 h; the calcining condition is that the temperature is raised to 400-600 ℃ at the temperature rising rate of 1-2 ℃ per minute, and the heat preservation time is 2-6 h at 400-600 ℃.
  4. 4. The production method according to claim 1, wherein in the step (2), the oxide solid electrolyte includes at least one of a perovskite type, a garnet type and a NASICON type.
  5. 5. The preparation method according to claim 1, wherein in the step (2), the drying temperature is 60-100 ℃ and the time is 6-48 h; The calcination condition is that the temperature is firstly kept at 250-350 ℃ for 1-3 hours, then the temperature is raised to 800-1000 ℃, and the temperature is kept at 3-5 h.
  6. 6. The method of preparing the material according to claim 1, wherein in the step (3), the method of removing the SiO 2 template comprises immersing the oxide/SiO 2 composite skeleton in a hydrofluoric acid aqueous solution with a mass concentration of 2-10%, and etching 12-24 h; The composite skeleton with SiO 2 removed is washed and dried for 4 to 18 hours at the temperature of between 60 and 80 ℃.
  7. 7. The process according to claim 1, wherein in the step (3), the silane hydrolysate is obtained by adding acetic acid to an ethanol solution of 3- (trihydroxysilyl) -1-propanol, adjusting pH to 3-5, and then hydrolyzing 1-4 h with stirring to obtain the silane hydrolysate; immersing in the silane hydrolysate for reaction of 3-24 h, washing with absolute ethyl alcohol for 2-3 times, and vacuum drying at 60-80 ℃ for 4-6h.
  8. 8. The method according to claim 1, wherein in the step (4), the polymer electrolyte precursor solution comprises a polymer precursor, a lithium salt and a solvent, wherein the mass ratio of the polymer precursor to the lithium salt is 1 (0.5-1.0), and the mass ratio of the polymer precursor to the solvent is 1 (10-20); Preferably, the polymer precursor is at least one of vinylidene fluoride, polyethylene oxide, polymethyl methacrylate, polyacrylonitrile and polydioxanone, the lithium salt is at least one of lithium bis (trifluoromethanesulfonyl) imide, lithium bis (fluorosulfonyl) imide, lithium nitrate, lithium tetrafluoroborate and lithium hexafluorophosphate, and the solvent is at least one of N-methylpyrrolidone, N-dimethylformamide, acetonitrile, tetrahydrofuran and fluoroether solvent.
  9. 9. The production method according to claim 1, wherein in the step (4), the mass ratio of the three-dimensional oxide solid electrolyte skeleton with surface-modified-OH groups to the polymer precursor contained in the polymer electrolyte precursor solution is 1 (0.6-4); The infiltration temperature is 35-50 ℃ and the time is 6-10h; the drying and curing temperature is 40-60 ℃ and the time is 8-24 h.
  10. 10. A composite solid electrolyte membrane having a three-dimensional network structure produced by the production method according to any one of claims 1 to 9.

Description

Composite solid electrolyte membrane with three-dimensional network structure and preparation method thereof Technical Field The invention belongs to the technical field of electrolyte, and in particular relates to a composite solid electrolyte membrane with a three-dimensional network structure and a preparation method thereof. Background As a substitute for liquid electrolytes with great potential for development, the development of solid electrolytes with high mechanical strength and high safety is an important direction for the development of lithium battery technology. However, the current solid-state battery is subject to factors such as low ion conductivity, high interface impedance, poor chemical stability and the like, so that the current solid-state battery is difficult to realize large-scale industrialized application. Among them, the polymer solid electrolyte has a good flexibility and can stabilize the interface, but has low ionic conductivity and mechanical strength, and the inorganic solid electrolyte represented by oxides and sulfides has high mechanical strength and high ionic conductivity, but has the defects of high interface resistance, poor chemical stability and the like. In order to solve the technical problems, researchers have proposed various strategies such as surface coating, element doping, multiphase compounding and the like. Among them, the inorganic/organic polymer solid electrolyte prepared by the heterogeneous composite method can integrate the advantages of inorganic and organic solid electrolytes and make up for the deficiency thereof, and is regarded as a very potential solid electrolyte development direction. However, this method has limitations in that inorganic particles dispersed in the composite solid electrolyte cannot construct a continuous lithium ion transport channel, and non-uniformity caused by particle agglomeration may lead to performance degradation. Therefore, simple combination of the polymer matrix and the inorganic material is difficult to effectively improve the ion conductivity, thereby affecting the overall performance of the semi-solid battery. Disclosure of Invention The invention aims to provide a composite solid electrolyte membrane with a three-dimensional network structure and a preparation method thereof, and the composite solid electrolyte membrane can improve ion conductivity and cycle performance and provide new material support for the development of solid batteries. In order to achieve the above object, an aspect of the present invention provides a method for preparing a composite solid electrolyte membrane having a three-dimensional network structure, the method comprising: (1) Immersing a silicon wafer into Polystyrene (PS) microsphere emulsion, and obtaining a SiO 2 inverse opal template through deposition and calcination; (2) Adding the SiO 2 inverse opal template into oxide solid electrolyte precursor liquid for infiltration, and then drying and calcining to obtain an oxide/SiO 2 composite framework; (3) Removing SiO 2 template in the oxide/SiO 2 composite framework, washing and drying the composite framework with SiO 2 removed, immersing the composite framework in silane hydrolysate for reaction, and finally washing and drying to obtain the three-dimensional oxide solid electrolyte framework with surface modified-OH groups; (4) Immersing the three-dimensional oxide solid electrolyte skeleton with the surface modified-OH group into polymer electrolyte precursor liquid for infiltration, and then drying and solidifying to obtain the composite solid electrolyte membrane with the three-dimensional network structure. According to the invention, in the step (1), preferably, the polystyrene microsphere emulsion is prepared by a method comprising the steps of adding a styrene monomer, an initiator and an emulsifier into water, and stirring to obtain the polystyrene microsphere emulsion; Preferably, the initiator is at least one of potassium persulfate, ammonium persulfate, azodiisobutyronitrile and dibenzoyl peroxide, the emulsifier is at least one of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, polyvinylpyrrolidone and cetyltrimethylammonium bromide, and the content of the styrene monomer is 20-40wt%, the content of the initiator is 0.5-1wt%, the content of the emulsifier is 0.2-3wt% and the balance is water based on the total weight of the styrene monomer, the initiator, the emulsifier and the water. According to the invention, preferably, in the step (1), the deposition temperature is 20-40 ℃, the relative humidity is 30-60%, and the deposition time is 6-24 h; The calcining condition is that the temperature is raised to 400-600 ℃ at the temperature rising rate of 1-2 ℃ per minute, and the heat preservation time is 2-6 h at 400-600 ℃. According to the present invention, preferably, in step (2), the oxide solid electrolyte includes at least one of perovskite type, garnet type and NASICON type. In the invention, the raw materia