LITHIUM-ALUMINUM HYDROTALCITE-BASED SOLID ELECTROLYTE FILM WORKING AT ROOM TEMPERATURE, PREPARATION METHOD THEREOF, AND LITHIUM BATTERY INCLUDING SAME

20240421347

18/696871

December 22, 2021

Disclosed are a lithium aluminum hydrotalcite-based solid electrolyte film, a preparation method and use thereof, and a lithium battery including the same. The lithium aluminum hydrotalcite-based solid electrolyte film includes: a solid electrolyte film substrate formed by an organic polymer, and a lithium salt and a lithium aluminum hydrotalcite uniformly dispersed in the solid electrolyte film substrate, wherein the lithium aluminum hydrotalcite has a content of 50 wt % to 80 wt %, based on a total mass of the solid electrolyte film substrate after removal of the lithium salt; and the organic polymer includes one or more selected from the group consisting of polyethylene glycol diacrylate, polyethylene oxide, polypropylene carbonate, and polyvinylidene fluoride-hexafluoropropylene copolymer.

1. A method for preparing a lithium aluminum hydrotalcite-based solid electrolyte film working at room temperature, comprising: step 1) dissolving a water-soluble lithium salt, a water-soluble aluminum salt, and a water-soluble meta-aluminate in deionized water that has been introduced with an inert gas and boiled to remove carbon dioxide, subjecting a resulting mixture to ultrasound or stirring to dissolve, then adding an alkali thereto to adjust a pH of the resulting mixture to 9 to 11, and controlling a temperature at 60° C. to 80° C., and subjecting a resulting adjusted mixture to reaction to produce a lithium aluminum hydrotalcite; step 2) calcination and grinding: placing the lithium aluminum hydrotalcite obtained in step 1) under protection of an inert gas, calcining at 100° C. to 150° C. for 2 h to 6 h to remove water between hydrotalcite layers to obtain a calcined sample, then grinding the calcined sample to power to obtain a lithium aluminum hydrotalcite powder; step 3) preparing a lithium aluminum hydrotalcite-based solid electrolyte slurry for later use by the following operations in a glove box: adding an organic solvent, an organic polymer, and a lithium salt into a container, stirring a resulting mixture to complete dissolution, then adding the lithium aluminum hydrotalcite powder to the resulting mixture, subjecting a resulting blend to ultrasound or stirring to homogeneous dispersion, then adding a photoinitiator or a thermal initiator thereto to obtain the lithium aluminum hydrotalcite-based solid electrolyte slurry; and wherein the organic polymer is polyethylene glycol diacrylate (PEGDA); and step 4) performing the following operations in a glove box: subjecting the lithium aluminum hydrotalcite-based solid electrolyte slurry obtained in step 3) to curing and film-forming to obtain the lithium aluminum hydrotalcite-based solid electrolyte film; wherein proportions of an inorganic phase and an organic phase in the solid electrolyte film are respectively as follows: a content of the inorganic phase lithium aluminum hydrotalcite is 59.9 wt %, and a content of the organic phase is 40.1%, based on a total mass of a solid electrolyte film after removal of the lithium salt; and in step 1), the water-soluble lithium salt is lithium chloride; the water-soluble aluminum salt is aluminum chloride; and a molar ratio of lithium to aluminum is in a range of 1:2 to 1:5.

2. The method for preparing the lithium aluminum hydrotalcite-based solid electrolyte film working at room temperature of claim 1, wherein in step 2), during the calcination process, the inert gas is argon and a heating rate is in a range of 5° C./min to 10° C./min.

3-6. (canceled)

7. The method for preparing the lithium aluminum hydrotalcite-based solid electrolyte film working at room temperature of claim 1, wherein in step 3), the organic solvent is one or more selected from the group consisting of N,N-dimethylacetamide, acetonitrile, ethylene carbonate (EC), and propylene carbonate (PC); and the photoinitiator is phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide, and the thermal initiator is azobisisobutyronitrile.

8. The method for preparing the lithium aluminum hydrotalcite-based solid electrolyte film working at room temperature of claim 1, wherein in step 4), the curing and film-forming is conducted by a process comprising: under the condition that the solid electrolyte slurry contains the PEGDA as the organic polymer and the photoinitiator is used in the step 3), transferring the slurry to a polytetrafluoroethylene plate, subjecting the slurry to scrape coating, then irradiating with an ultraviolet (UV) lamp with a UV wavelength of 365 nm for 5 min to 20 min, so that the slurry is cured to form the film; or under the condition that the solid electrolyte slurry contains the PEGDA as the organic polymer and the thermal initiator is used in the step 3), subjecting the slurry to scrape coating, then heating on a heating stage at 60° C. for 5 min to 20 min, so that the slurry is cured to form the film.

9. The method of for preparing the lithium aluminum hydrotalcite-based solid electrolyte film working at room temperature of claim 1, wherein under the condition that the organic polymer is the PEGDA, a molar ratio of an ethylene oxide (EO) segment to lithium ion is in a range of 16:1 to 20:1.

10-11. (canceled)

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