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CN-121983661-A - Composite solid electrolyte membrane, preparation method thereof and battery

CN121983661ACN 121983661 ACN121983661 ACN 121983661ACN-121983661-A

Abstract

The application belongs to the technical field of batteries, and particularly relates to a composite solid electrolyte membrane, a preparation method thereof and a battery. The method comprises the steps of mixing perfluorinated sulfonic acid polymer and alkali metal compound, carrying out neutralization reaction to obtain first mixed solution, stirring and mixing the first mixed solution and alcohol solvent to obtain second mixed solution, stirring and mixing the second mixed solution, polyvalent metal ion compound and metal oxide nano particles to form composite slurry, coating the composite slurry on the surface of a current collector, and carrying out gradient drying to obtain the composite solid electrolyte membrane. The method improves the ionic conductivity of the solid electrolyte membrane and improves the coating uniformity or the membrane layer compactness.

Inventors

  • CHEN LIN
  • Gao Tingsong

Assignees

  • 深圳欣界能源科技股份有限公司

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. A method of making a composite solid electrolyte membrane comprising: mixing perfluorinated sulfonic acid polymer with alkali metal compound for neutralization reaction to obtain a first mixed solution; Mixing and stirring the first mixed solution and an alcohol solvent to obtain a second mixed solution; stirring and mixing the second mixed solution, the multivalent metal ion compound and the metal oxide nano particles to form composite slurry; coating the composite slurry on the surface of a current collector and performing gradient drying to obtain a composite solid electrolyte membrane; wherein the alkali metal compound comprises the alkali metal hydroxide and the alkali metal carbonate in a molar ratio of (0.5-2): 1.
  2. 2. The preparation method according to claim 1, wherein the alkali metal compound comprises at least one of an alkali metal hydroxide and an alkali metal carbonate, preferably at least one of lithium hydroxide, sodium hydroxide, lithium carbonate and sodium carbonate.
  3. 3. The method according to claim 2, wherein the molar ratio of the alkali metal hydroxide to the alkali metal carbonate is 1 (1.2 to 1.7).
  4. 4. The preparation method according to claim 1, wherein the alcohol solvent comprises a monohydric alcohol of C1 to C4, preferably at least one of ethanol and isopropanol.
  5. 5. The process according to claim 4, wherein the ratio of the total mass of the alcohol solvent to the perfluorosulfonic acid polymer is (0.5-5): 1, preferably (2-3): 1.
  6. 6. The method according to claim 1, wherein at least one of the following conditions is satisfied that the metal ions in the polyvalent metal ion compound comprise at least one of Ca2 + 、Mg² + 、Ba² + 、Al³ + 、Zn² + , preferably Ca 2+ ; The metal oxide nanoparticles comprise at least one of ZnO and TiO 2 、Al 2 O 3 、SiO 2 , preferably ZnO.
  7. 7. The production method according to claim 1, wherein the molar amount of the polyvalent metal ion in the polyvalent metal ion compound is 0.5 to 3.5% of the molar amount of the sulfonic acid group in the perfluorosulfonic acid polymer, based on the molar amount of the sulfonic acid group in the perfluorosulfonic acid polymer, and/or The mass of the metal oxide nano particles is 0.5% -3.5% of the mass of the perfluorinated sulfonic acid type polymer.
  8. 8. The method according to claim 1, wherein the gradient drying comprises drying the coated product at 40-60 ℃, starting from a first vacuum degree, reducing the vacuum degree by 0.005MPa~0.015 MPa every 1-3 hours until reaching a second vacuum degree, and maintaining the vacuum degree for 1-4 hours, wherein the first vacuum degree is-0.03-0.07-MPa, and the second vacuum degree is-0.08-0.15-MPa.
  9. 9. A composite solid electrolyte membrane prepared according to the method of any one of claims 1-8.
  10. 10. A battery comprising the composite solid electrolyte membrane of claim 9.

Description

Composite solid electrolyte membrane, preparation method thereof and battery Technical Field The application belongs to the technical field of batteries, and particularly relates to a composite solid electrolyte membrane, a preparation method thereof and a battery. Background Lithium metal batteries are widely concerned due to their high energy density, but at present they still face two major core bottlenecks, namely the risk of internal short circuits of the battery caused by non-uniform and uncontrollable lithium dendrite growth, and the rapid drop in capacity caused by the accumulation of lithium due to the continuous side reactions occurring in the cycle, resulting in the reduction of the cycle life of the battery. While solid electrolyte membranes have a critical impact on the performance of the cell. Therefore, the solid electrolyte membrane needs to be further 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 a composite solid electrolyte membrane, a preparation method thereof and a battery. The method improves the ionic conductivity of the solid electrolyte membrane and improves the coating uniformity or the membrane layer compactness. In a first aspect of the present application, a method for preparing a composite solid electrolyte membrane is provided, comprising: mixing a perfluorinated sulfonic acid polymer with an alkali metal compound, and carrying out neutralization reaction to obtain a first mixed solution; stirring and mixing the first mixed solution and an alcohol solvent to obtain a second mixed solution; stirring and mixing the second mixed solution, the multivalent metal ion compound and the metal oxide nano particles to form composite slurry; and coating the composite slurry on the surface of a current collector and carrying out gradient drying to obtain the composite solid electrolyte membrane. According to the application, three methods of metal ion complexation, solution modification and gradient drying are cooperatively combined, so that the ionic conductivity of the solid electrolyte membrane is improved, the fluidity and dispersibility of the composite slurry are optimized, the uniform coating is ensured, meanwhile, the internal stress caused by rapid volatilization of the solvent is reduced by gradient drying, and the compactness of the membrane layer is improved. The solid electrolyte membrane obtained by the method is uniform and compact, has no damage, remarkably improves the mechanical strength and the ionic conductivity, can be tightly attached to a negative current collector, effectively inhibits dendrite, and improves the capacity retention rate of the battery. According to an embodiment of the application, the alkali metal compound comprises at least one of an alkali metal hydroxide, an alkali metal carbonate, preferably at least one of lithium hydroxide, sodium hydroxide, lithium carbonate, sodium carbonate. According to an embodiment of the present application, the alkali metal compound includes the alkali metal hydroxide and the alkali metal carbonate in a molar ratio of (0.5-2): 1, specifically (1.2-1.7): 1. According to an embodiment of the present application, the alcoholic solvent comprises a monohydric alcohol of C1-C4, preferably at least one of ethanol and isopropanol. According to the embodiment of the application, the ratio of the total added mass of the alcohol solvents to the mass of the perfluorinated sulfonic acid polymer is (0.5-5): 1, specifically (2-3): 1. According to an embodiment of the application, the above method fulfils at least one of the following conditions: The metal ions in the polyvalent metal ion compound comprise at least one of Ca2 +、Mg²+、Ba²+、Al³+、Zn²+, in particular Ca 2+; The metal oxide nanoparticles comprise at least one of ZnO and TiO 2、Al2O3、SiO2, preferably ZnO. According to an embodiment of the present application, the polyvalent metal ion compound has a molar amount of polyvalent metal ion of 0.5 to 5% based on the molar amount of sulfonic acid groups in the perfluorosulfonic acid type polymer, and/or The mass of the metal oxide nano particles is 0.5% -5% of the mass of the perfluorinated sulfonic acid type polymer. According to the embodiment of the application, the gradient drying comprises the steps of drying the coated product at 40-60 ℃, starting from a first vacuum degree, increasing the vacuum degree by 0.005-0.015 MPa every 1-3 h until reaching a second vacuum degree, and maintaining for 1-4 h, wherein the first vacuum degree is-0.04-0.06-MPa, and the second vacuum degree is-0.09-0.11-MPa. In a second aspect of the present application, a composite solid electrolyte membrane is provided, prepared according to the method of the first aspect. All features and advantages of the composite solid electrolyte membrane, including all features and advantages of the method of manufacturing according to