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CN-121035330-B - Sulfur-containing all-solid-state polymer electrolyte membrane for energy storage type lithium battery and preparation method thereof

CN121035330BCN 121035330 BCN121035330 BCN 121035330BCN-121035330-B

Abstract

The invention discloses a sulfur-containing all-solid polymer electrolyte membrane for an energy storage type lithium battery and a preparation method thereof, and belongs to the technical field of polymer electrolytes. The preparation method of the sulfur-containing all-solid polymer electrolyte membrane comprises the steps of uniformly mixing 2,2' -diaminodiphenyl disulfide and vulcanized divinyl, obtaining polymer solids through polymerization reaction, dissolving the polymer solids in dimethyl sulfoxide to obtain a mixed solution, adding lithium bis (trifluoromethanesulfonyl) imide into the mixed solution, uniformly mixing to obtain a precursor solution, pouring the precursor solution into a mold, and vacuum drying to obtain the sulfur-containing all-solid polymer electrolyte membrane. The electrolyte membrane provided by the invention perfectly solves the technical problems of low ionic conductivity, insufficient migration number of lithium ions, serious interface polarization and weak oxidation resistance of the traditional solid electrolyte through a triple mechanism. Meanwhile, the lithium metal battery assembled by the sulfur-containing all-solid-state polymer electrolyte has excellent electrochemical performance and cycle performance.

Inventors

  • YANG JIAMING
  • GU ZHENYU
  • WU JIAN
  • LI XIAOCHEN
  • JIANG HUI
  • WANG WENHUA
  • CHEN JIE
  • Guan Jianian

Assignees

  • 西安热工研究院有限公司
  • 华能上海石洞口发电有限责任公司

Dates

Publication Date
20260512
Application Date
20250825

Claims (10)

  1. 1. The sulfur-containing all-solid polymer electrolyte membrane is characterized by being prepared from a sulfur-containing all-solid polymer through hot melting, pouring and evaporating, wherein the sulfur-containing all-solid polymer has a structural general formula as follows: wherein n is the polymerization degree, and n is more than or equal to 5000 and less than or equal to 50000.
  2. 2. The sulfur-containing all-solid polymer electrolyte membrane according to claim 1, wherein the thickness of the sulfur-containing all-solid polymer electrolyte membrane is 55 μm±5 μm.
  3. 3. A method for preparing the sulfur-containing all-solid polymer electrolyte membrane according to claim 1, comprising the steps of: uniformly mixing 2,2' -diaminodiphenyl disulfide and vulcanized divinyl, and obtaining polymer solid through polymerization reaction; Dissolving polymer solids in dimethyl sulfoxide to obtain a mixed solution, adding lithium bistrifluoromethane sulfonyl imide into the mixed solution, and uniformly mixing to obtain a precursor solution; pouring the precursor solution into a mould, and vacuum drying to obtain the sulfur-containing all-solid polymer electrolyte membrane.
  4. 4. The method for producing a sulfur-containing all-solid polymer electrolyte membrane according to claim 3, wherein the mass ratio of 2,2' -diaminodiphenyl disulfide to vulcanized divinyl is 1 (1-8).
  5. 5. The method for preparing a sulfur-containing all-solid polymer electrolyte membrane according to claim 3, wherein the polymerization reaction is carried out in an oil bath environment at a temperature of 80-160 ℃ for 30-120 min, and the polymer solid is obtained by cooling to room temperature after the completion of the reaction.
  6. 6. The method for preparing a sulfur-containing all-solid polymer electrolyte membrane according to claim 3, wherein the addition amount of the lithium bistrifluoromethane sulfonyl imide is 20% -80% of the total mass of 2,2' -diaminodiphenyl disulfide and vulcanized divinyl.
  7. 7. The method for preparing a sulfur-containing all-solid polymer electrolyte membrane according to claim 3, wherein lithium bis (trifluoromethanesulfonyl) imide is added into the mixed solution, and the mixture is magnetically stirred for 12-48 hours at the temperature of 25-60 ℃ until the precursor solution is obtained after the mixture is uniformly mixed.
  8. 8. The method for preparing a sulfur-containing all-solid polymer electrolyte membrane according to claim 3, wherein the specific method for pouring the precursor solution into the mold is as follows: Slowly pouring the precursor solution in the central position of the PTFE mould until the PTFE mould is fully paved, and stopping pouring; The depth of the PTFE mold is 250-350 mu m.
  9. 9. The method for preparing a sulfur-containing all-solid polymer electrolyte membrane according to claim 3, wherein the temperature of vacuum drying is 25-130 ℃ and the drying time is 12-24 hours.
  10. 10. Use of the sulfur-containing all-solid polymer electrolyte membrane according to claim 1 or 2 for a lithium ion battery.

Description

Sulfur-containing all-solid-state polymer electrolyte membrane for energy storage type lithium battery and preparation method thereof Technical Field The invention belongs to the technical field of polymer electrolytes, and particularly relates to a sulfur-containing all-solid polymer electrolyte membrane for an energy storage type lithium battery and a preparation method thereof. Background Lithium metal batteries are an ideal choice for energy storage devices due to their outstanding energy density and cycling stability. However, the problems of flammability, severe side reaction with lithium metal and the like of the traditional organic liquid electrolyte lead to potential safety hazards such as electrode corrosion, uncontrolled growth of dendrites and the like, and seriously restrict the commercialized application of the electrolyte. The solid electrolyte can inhibit the penetration of lithium dendrites, so that the risk of thermal runaway is reduced, and the solid electrolyte becomes a key path for breaking through the safety bottleneck. Currently, solid electrolytes are largely classified into inorganic and polymer systems, and polymer types are of great interest because of their good flexibility and suitability for processing. However, conventional polymer electrolyte materials, represented by polyethylene oxide (PEO), still face many challenges. For example, the ionic conductivity at room temperature is generally low, the quick charge requirement is difficult to meet, the contact impedance of an electrode/electrolyte interface is large, the polarization is aggravated, an electrochemical stability window is narrow, oxidative decomposition is easy to occur under a high-pressure condition, the mechanical strength is insufficient, and the penetration of lithium dendrites is difficult to continuously inhibit. In recent years, various novel polymer electrolyte systems such as nitrile groups, siloxanes, carbonates and polyvinylidene fluoride groups have been developed successively, but they often have difficulty in achieving a combination of high ionic conductivity, excellent mechanical strength and desirable safety due to the inherent characteristics of a single polymer backbone structure. Aiming at the challenge, the organic polysulfide electrolyte is focused on the structural characteristics that a polysulfide chain segment- (S-S) n -forms a high-efficiency lithium ion transmission channel by virtue of abundant sulfur atoms and lone pair electrons, the low electronegativity of sulfur element not only obviously reduces the lithium ion migration energy barrier and improves the ion conductivity and the circulation stability, but also effectively improves the interface compatibility, and the unique dynamic S-S bond further endows the material with self-repairing capability, thereby being beneficial to inhibiting the generation of lithium dendrite. Nevertheless, such electrolytes still face limitations in practical applications, particularly in electrochemical stability under high voltage conditions, inhibiting anion migration to increase lithium ion migration number, enhancing interfacial compatibility to mitigate polarization, and fully performing self-healing functions, which limits breakthroughs in solid-state lithium batteries over long cycle life and interfacial stability. Disclosure of Invention In order to overcome the technical problems of low ionic conductivity, insufficient migration number of lithium ions, serious interface polarization and weak oxidation resistance of the traditional solid electrolyte, the invention provides a sulfur-containing all-solid polymer electrolyte membrane for an energy storage type lithium battery and a preparation method thereof, and the three synergistic mechanisms of sulfur chain coordination conduction, amino bidentate chelation and dynamic S-S bond repair are adopted to break through the bottleneck of solid battery interface stability and long cycle life. In order to achieve the above purpose, the invention is realized by adopting the following technical scheme: in a first aspect, the invention provides a sulfur-containing all-solid polymer electrolyte membrane, which is prepared from a sulfur-containing all-solid polymer through hot melting, pouring and evaporating, wherein the sulfur-containing all-solid polymer has a structural general formula as follows: wherein n is the polymerization degree, and n is more than or equal to 5000 and less than or equal to 50000. A further improvement of the present invention is that the thickness of the sulfur-containing all-solid polymer electrolyte membrane is 55 μm.+ -. 5. Mu.m. In a second aspect, the present invention also provides a method for preparing a sulfur-containing all-solid polymer electrolyte membrane, comprising the steps of: uniformly mixing 2,2' -diaminodiphenyl disulfide and vulcanized divinyl, and obtaining polymer solid through polymerization reaction; Dissolving polymer solids in dimethyl sulfoxide to ob