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CN-121839851-B - Preparation method and application of solid electrolyte membrane based on sulfamate cellulose lithium

CN121839851BCN 121839851 BCN121839851 BCN 121839851BCN-121839851-B

Abstract

The invention relates to the technical field of solid electrolyte of lithium ion batteries, in particular to a preparation method and application of a solid electrolyte membrane based on sulfamate cellulose lithium. The preparation method comprises the following steps of S1, pretreatment and acidification reaction, S2, performing sulfamate grafting on CMC-H to obtain a reaction solution, S3, preparing sulfamate cellulose lithium, S4, preparing a solid electrolyte membrane, wherein S401, dispersing the sulfamate cellulose lithium into a solvent, stirring until the sulfamate cellulose lithium is dissolved, adding a modifier and a modified filler, performing ultrasonic dispersion to obtain slurry, S402, knife-coating the slurry on a release film, drying, hot-pressing, cooling to room temperature, stripping the release film, and drying to obtain the solid electrolyte membrane based on the sulfamate cellulose lithium. The invention provides a preparation method and application of a solid electrolyte membrane based on lithium sulfamate cellulose, which are used for solving the problems of low ionic conductivity, high interface impedance and easiness in oxidative decomposition of the solid electrolyte membrane in the related technology.

Inventors

  • QIU LEI
  • ZHANG LIN
  • LIU CHUNYAN
  • Jia Yueyue

Assignees

  • 绿能纤材(重庆)科技有限公司

Dates

Publication Date
20260508
Application Date
20260306

Claims (9)

  1. 1. A method for preparing a solid electrolyte membrane based on lithium aminosulfonate cellulose, characterized in that it comprises the following steps: s1, pretreatment and acidification reaction: s101, dispersing lithium carboxymethyl cellulose in absolute ethyl alcohol, stirring and dispersing for 30-40 min, adding a catalytic auxiliary agent, and stirring to obtain a suspension; s102, dropwise adding sulfuric acid solution, acidizing to adjust the pH value to 3.5-4, carrying out heat preservation reaction for 1-2 hours at 28-30 ℃, carrying out suction filtration, washing until the pH value of filtrate is 5.5-6, carrying out vacuum drying for 4-5 hours at 58-60 ℃, and crushing to obtain an acidized intermediate carboxymethyl cellulose acid CMC-H; S2, performing sulfamate grafting on CMC-H to obtain a reaction solution; S3, preparing sulfamate cellulose lithium: s301, dropwise adding LiOH into the reaction liquid, adjusting the pH to 9-10, and stirring and reacting for 2-3 hours at the temperature of 30-35 ℃; S302, filtering and collecting a product, washing, drying at room temperature for 25-30 min, and then vacuum drying at 55-60 ℃ for 6-7 h to obtain aminosulfonated cellulose lithium; S4, preparing a solid electrolyte membrane: s401, dispersing (5-6) of the sulfamate cellulose lithium into a solvent according to the mass volume ratio of 1g, stirring until the sulfamate cellulose lithium is dissolved, adding a modifier and a modified filler, continuously stirring for 1-2 hours, and performing ultrasonic dispersion to obtain slurry; the solvent comprises deionized water and 95wt% ethanol solution with the volume ratio of (0.9-1); The modified filler comprises (1-1.2) inorganic filler and a filler modifier in a mass ratio, wherein the inorganic filler is selected from at least one of graphene nano-sheets and montmorillonite, and the filler modifier is selected from one of lipoic acid and mercaptopropionic acid; The preparation method of the modifier comprises the following steps: Dispersing polyethylene glycol, polyetherimide and 2-furanmethanamine into deionized water, and stirring and reacting for 25-30 min at 35-40 ℃ to obtain a modifier, wherein the mass ratio of the polyethylene glycol, the polyetherimide, the 2-furanmethanamine and the deionized water is 5 (2-2.5): (0-1): 10; And S402, uniformly scraping the slurry on a polytetrafluoroethylene release film, wherein the scraping thickness is 30-100 mu m, drying at 55-60 ℃ for 1.5-2 hours, then placing into a hot press, cooling to room temperature after hot pressing, stripping the polytetrafluoroethylene release film, and continuously drying at 60-70 ℃ for 5-6 hours to obtain the solid electrolyte film based on the aminosulfonated cellulose lithium.
  2. 2. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 1, characterized in that: The step S2 comprises the following steps: dispersing CMC-H into a solvent system according to the mass volume ratio of 1g (10-12) mL, and stirring and dissolving at 40-45 ℃; Adding an amino sulfonation reagent, adding triethylene tetramine, adjusting the pH to 7.5-8, and carrying out heat preservation reaction for 3-4 hours at 40-50 ℃ under the stirring condition to complete amino sulfonation grafting, thereby obtaining a reaction solution; the mass ratio of the sulfamation reagent to CMC-H is (1.375-1.5): 1; The solvent system is selected from one or more of deionized water and absolute ethyl alcohol.
  3. 3. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 2, characterized in that: In S2, the sulfamating agent is selected from sulfamic acid or lithium sulfamate.
  4. 4. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 2, characterized in that: In the S2, after CMC-H is dispersed in a solvent system, sorbic acid is added, wherein the adding mass of the sorbic acid is 5-6% of the mass of the CMC-H.
  5. 5. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 1, characterized in that: In the step S1, the catalyst auxiliary agent is selected from urea, and the mass ratio of the urea to the lithium carboxymethyl cellulose is 1 (10-12).
  6. 6. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 1, characterized in that: In S401, the preparation method of the modified filler includes the following steps: Dispersing inorganic filler into deionized water, then performing ultrasonic dispersion for 10-15 min, adding a filler modifier, stirring for 1-1.5 h at 45-50 ℃, and performing centrifugal separation and drying to obtain modified filler; The mass ratio of the inorganic filler to the deionized water is 1:5.
  7. 7. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 1, characterized in that: In S401, the inorganic filler comprises graphene nano-sheets and montmorillonite with a mass ratio of 1 (1-2).
  8. 8. The method for producing a solid electrolyte membrane based on lithium sulfamate according to claim 1, characterized in that: in the step S402, the hot pressing condition is that the hot pressing is carried out for 25-30 min at 70-80 ℃ and 4-5 MPa.
  9. 9. Use of a solid electrolyte membrane prepared by the method for preparing a solid electrolyte membrane based on lithium sulfamate according to any one of claims 1 to 8 in a lithium battery.

Description

Preparation method and application of solid electrolyte membrane based on sulfamate cellulose lithium Technical Field The application relates to the technical field of solid electrolyte of lithium ion batteries, in particular to a preparation method and application of a solid electrolyte membrane based on sulfamate cellulose lithium. Background The solid electrolyte membrane is a film component taking a solid ion conductor as a core material, realizes the ion selective transmission function through an electrochemical separation principle, and is mainly applied to the fields of all-solid batteries, hydrogen fuel cells and the like. The electrolyte does not depend on a liquid solvent, has the functions of ion conduction, electronic insulation, physical isolation and safety guarantee, and has the advantages of incombustibility, no leakage, high stability, capability of being matched with a lithium metal negative electrode to improve energy density and the like compared with the traditional liquid electrolyte. The existing solid electrolyte membrane still has a plurality of technical bottlenecks in material selection and preparation process, and especially the cellulose-based solid electrolyte membrane becomes a research hot spot due to the characteristics of wide raw material sources, good biocompatibility, low cost and the like. The cellulose-based polymer molecular chain has a natural regular structure, the crystallinity is higher, the ion conduction mainly depends on molecular chain segment movement and ion migration channels of a polymer amorphous region, the molecular chain segment movement is slow at room temperature, the ion conductivity is lower, and an inherent interface gap exists between the sulfamated cellulose lithium salt and a metal lithium negative electrode, so that the interface impedance is obviously increased, meanwhile, the sulfamated cellulose salt is easy to be oxidized and decomposed in a high-potential environment to generate insulating products to be deposited on an interface, the continuity of ion transmission is further damaged, and the practical use requirement of the all-solid-state battery is difficult to meet. Disclosure of Invention The application provides a preparation method and application of a solid electrolyte membrane based on lithium sulfamate cellulose, which are used for solving the problems of low ionic conductivity, high interface impedance and easiness in oxidative decomposition of the solid electrolyte membrane in the related technology. In a first aspect, there is provided a method for preparing a solid electrolyte membrane based on lithium sulfamate, comprising the steps of: s1, pretreatment and acidification reaction: s101, dispersing lithium carboxymethyl cellulose in absolute ethyl alcohol, stirring and dispersing for 30-40 min, adding a catalytic auxiliary agent, and stirring to obtain a suspension; s102, dropwise adding sulfuric acid solution, acidizing to adjust the pH value to 3.5-4, carrying out heat preservation reaction for 1-2 hours at 28-30 ℃, carrying out suction filtration, washing until the pH value of filtrate is 5.5-6, carrying out vacuum drying for 4-5 hours at 58-60 ℃, and crushing to obtain an acidized intermediate carboxymethyl cellulose acid CMC-H; S2, performing sulfamate grafting on CMC-H to obtain a reaction solution; S3, preparing sulfamate cellulose lithium: s301, dropwise adding LiOH into the reaction liquid, adjusting the pH to 9-10, and stirring and reacting for 2-3 hours at the temperature of 30-35 ℃; S302, filtering and collecting a product, washing, drying at room temperature for 25-30 min, and then vacuum drying at 55-60 ℃ for 6-7 h to obtain aminosulfonated cellulose lithium; S4, preparing a solid electrolyte membrane: s401, dispersing (5-6) of the sulfamate cellulose lithium into a solvent according to the mass volume ratio of 1g, stirring until the sulfamate cellulose lithium is dissolved, adding a modifier and a modified filler, continuously stirring for 1-2 hours, and performing ultrasonic dispersion to obtain slurry; the solvent comprises deionized water and 95wt% ethanol solution with the volume ratio of (0.9-1); The modified filler comprises (1-1.2) inorganic filler and a filler modifier in a mass ratio, wherein the inorganic filler is selected from at least one of graphene nano-sheets and montmorillonite, and the filler modifier is selected from one of lipoic acid and mercaptopropionic acid; The preparation method of the modifier comprises the following steps: Dispersing polyethylene glycol, polyetherimide and 2-furanmethanamine into deionized water, and stirring and reacting for 25-30 min at 35-40 ℃ to obtain a modifier, wherein the mass ratio of the polyethylene glycol, the polyetherimide, the 2-furanmethanamine and the deionized water is 5 (2-2.5): (0-1): 10; And S402, uniformly scraping the slurry on a polytetrafluoroethylene release film, wherein the scraping thickness is 30-100 mu m, drying at 55-60 ℃ for 1.5-2 ho