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CN-122000442-A - Sulfide electrolyte film preparation method of all-solid-state battery

CN122000442ACN 122000442 ACN122000442 ACN 122000442ACN-122000442-A

Abstract

The invention discloses a method for preparing sulfide electrolyte film of all-solid-state battery, which comprises the steps of preparing interface modified slurry containing fast ion conductor, polymer elastomer and photoinitiator, preparing electrolyte functional slurry containing sulfide electrolyte and crosslinkable binder, coating two layers of slurry on a substrate to form a composite wet film, carrying out synchronous hot pressing and ultraviolet irradiation treatment on the composite wet film to realize interface in-situ crosslinking and densification, and optionally stripping and winding. According to the invention, through the key component collocation and the synergistic process, the interface compatibility is effectively improved, the ion transmission impedance is reduced, the penetration of lithium dendrites is inhibited, and the prepared sulfide electrolyte film has high ion conductivity, high compactness and excellent mechanical stability. After the film is applied to all-solid-state batteries, the cycling stability, the multiplying power performance and the safety of the batteries can be obviously improved, and the preparation process is suitable for large-scale production, and has important significance for promoting the industrialization of all-solid-state batteries.

Inventors

  • HAN YONGBIN

Assignees

  • 东莞力朗电池科技有限公司

Dates

Publication Date
20260508
Application Date
20260209

Claims (8)

  1. 1. A method for preparing a sulfide electrolyte film of an all-solid-state battery, comprising the steps of: Step S1, preparing interface modification slurry, namely mixing an interface modifier with a first solvent to obtain the interface modification slurry, wherein the interface modifier comprises a fast ion conductor and a polymer elastomer; Step S2, preparing electrolyte functional slurry, namely mixing sulfide electrolyte, a binder and a second solvent to obtain the electrolyte functional slurry; Step S3, composite coating, namely coating the interface modification slurry on a substrate to form a modification layer, and coating the electrolyte functional slurry on the modification layer to form an electrolyte layer to obtain a composite wet film; and S4, performing in-situ crosslinking and densification treatment, namely performing synchronous hot pressing and ultraviolet irradiation treatment on the composite wet film, so that the interface between the modification layer and the electrolyte layer is in-situ crosslinked, and the composite wet film is densified to form a sulfide electrolyte film.
  2. 2. The method for preparing a sulfide electrolyte film of an all-solid-state battery according to claim 1, wherein in the step S1, the fast ion conductor is at least one of lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide or lithium nitride, and the polymer elastomer is at least one of polyurethane, polybutadiene or styrene-butadiene-styrene block copolymer.
  3. 3. The method for preparing a sulfide electrolyte film for an all-solid-state battery according to claim 1, wherein in step S1, a photoinitiator is further included in the interface modification slurry, and the photoinitiator is at least one of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone or 1-hydroxycyclohexyl phenyl ketone.
  4. 4. The method for producing a sulfide electrolyte film for an all-solid state battery according to claim 1, wherein in step S3, the coating is performed by a micro gravure coating method, the wet film thickness of the finishing layer is 1 to 5. Mu.m, and the wet film thickness of the electrolyte layer is 10 to 50. Mu.m.
  5. 5. The method for preparing a sulfide electrolyte film for an all-solid-state battery according to claim 1, wherein in the step S4, the heat pressing treatment is performed at a temperature of 60-100 ℃, a pressure of 10-50MPa, and a time of 1-10 minutes, the ultraviolet irradiation is performed at a wavelength of 320-400nm, and an irradiation intensity of 50-200mW/cm2.
  6. 6. The method for producing a sulfide electrolyte film for an all-solid state battery according to any one of claims 1 to 5, wherein in step S2, the binder is a crosslinkable binder containing a carbon-carbon double bond, which is at least one of a modified styrene-butadiene rubber, a modified polyacrylate, or an ethylene-vinyl acetate copolymer.
  7. 7. The method for preparing a sulfide electrolyte film for an all-solid state battery according to claim 6, wherein the modified styrene-butadiene rubber is a styrene-butadiene rubber modified by maleic anhydride grafting.
  8. 8. The method according to any one of claims 1 to 5, further comprising, after step S4, step S5 of peeling and winding, namely peeling the sulfide electrolyte film from the substrate and winding.

Description

Sulfide electrolyte film preparation method of all-solid-state battery Technical Field The invention relates to the technical field of batteries, in particular to a method for preparing a sulfide electrolyte film of an all-solid-state battery. Background The all-solid-state battery has no potential safety hazards such as liquid electrolyte leakage and explosion, and the energy density and the cycling stability are obviously superior to those of the traditional liquid battery, so that the all-solid-state battery becomes a core research and development direction in the new energy field. Sulfide electrolyte is a key material for preparing a high-performance all-solid-state battery because of high lithium ion mobility and low electronic conductivity, and the preparation quality of a film directly determines the overall performance of the battery. At present, the sulfide electrolyte film preparation has a plurality of technical bottlenecks, such as poor interface compatibility, easy generation of gaps between an electrolyte layer and a substrate and between electrodes, high ion transmission impedance, difficulty in realizing uniform compounding of a modification layer and the electrolyte layer, poor film thickness controllability, multi-step crosslinking and densification, easy occurrence of problems of loose interface combination, film rebound and too high porosity, incapability of effectively inhibiting penetration of lithium dendrites, complex process, low production efficiency and difficulty in adapting to large-scale production. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides a method for preparing a sulfide electrolyte film of an all-solid-state battery, which can effectively solve the problems proposed by the background technology. The technical scheme adopted for solving the technical problems is as follows: a method for preparing a sulfide electrolyte film of an all-solid-state battery, comprising the steps of: Step S1, preparing interface modification slurry, namely mixing an interface modifier with a first solvent to obtain the interface modification slurry, wherein the interface modifier comprises a fast ion conductor and a polymer elastomer; Step S2, preparing electrolyte functional slurry, namely mixing sulfide electrolyte, a binder and a second solvent to obtain the electrolyte functional slurry; Step S3, composite coating, namely coating the interface modification slurry on a substrate to form a modification layer, and coating the electrolyte functional slurry on the modification layer to form an electrolyte layer to obtain a composite wet film; and S4, performing in-situ crosslinking and densification treatment, namely performing synchronous hot pressing and ultraviolet irradiation treatment on the composite wet film, so that the interface between the modification layer and the electrolyte layer is in-situ crosslinked, and the composite wet film is densified to form a sulfide electrolyte film. As a further description of the above technical solution, in step S1, the fast ion conductor is at least one of lithium lanthanum zirconium oxide, lithium lanthanum titanium oxide or lithium nitride, and the polymer elastomer is at least one of polyurethane, polybutadiene or styrene-butadiene-styrene block copolymer. As a further description of the above technical solution, in step S1, the interface modification slurry further includes a photoinitiator, where the photoinitiator is at least one of benzoin dimethyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, or 1-hydroxycyclohexyl phenyl ketone. As a further description of the above technical solution, in step S3, the coating is performed by a micro gravure coating method, the wet film thickness of the finishing layer is 1 to 5 μm, and the wet film thickness of the electrolyte layer is 10 to 50 μm. As a further description of the technical scheme, in the step S4, the temperature of the hot pressing treatment is 60-100 ℃, the pressure is 10-50MPa, the time is 1-10 minutes, the wavelength of the ultraviolet irradiation is 320-400nm, and the irradiation intensity is 50-200mW/cm < 2 >. As a further description of the above technical solution, in step S2, the binder is a crosslinkable binder containing a carbon-carbon double bond, which is at least one of modified styrene-butadiene rubber, modified polyacrylate, or ethylene-vinyl acetate copolymer. As a further description of the above technical solution, the modified styrene-butadiene rubber is a styrene-butadiene rubber modified by maleic anhydride grafting. As a further description of the technical scheme, after the step S4, the method further comprises the step S5 of stripping and winding, namely stripping the sulfide electrolyte film from the substrate and winding. Compared with the prior art, the invention has the beneficial effects that: the preparation method of the sulfide electrolyte film of the all-solid-state battery has at least one of the followi