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CN-121983639-A - Lithium ion solid-state battery and preparation method thereof

CN121983639ACN 121983639 ACN121983639 ACN 121983639ACN-121983639-A

Abstract

The invention relates to the technical field of lithium ion solid-state batteries, in particular to a lithium ion solid-state battery and a preparation method thereof. A lithium ion solid battery comprises a positive electrode plate, a solid polymer electrolyte membrane and a lithium metal negative electrode plate which are assembled together, wherein the polymer electrolyte membrane is prepared by respectively adding 3, 6-dioxa-1, 8-octanedithiol and triglycidyl isocyanurates into a solvent, stirring to obtain a mixed solution, adding bis (trifluoromethyl sulfonyl) imide lithium into the mixed solution, dissolving to obtain a precursor solution, and crosslinking and polymerizing the precursor solution to form a film. The lithium ion solid-state battery of the present invention exhibits excellent capacity, excellent cycle stability and reversibility.

Inventors

  • BI SHUGUANG
  • ZHANG YI
  • YANG YINGKUI
  • CHENG YU
  • RAN JIANHUA
  • HU JIAN

Assignees

  • 武汉纺织大学

Dates

Publication Date
20260505
Application Date
20260208

Claims (9)

  1. 1. The lithium ion solid-state battery is characterized by comprising a positive electrode plate, a solid polymer electrolyte membrane and a lithium metal negative electrode plate which are assembled together, wherein the solid polymer electrolyte membrane is prepared by the following method: S1, taking N, N-dimethylformamide, respectively adding 3, 6-dioxa-1, 8-octane dithiol and isocyanuric acid triglycidyl ester, and uniformly mixing to obtain a mixed solution; S2, adding lithium bis (trifluoromethylsulfonyl) imide into the mixed solution, and stirring to completely dissolve the lithium bis (trifluoromethylsulfonyl) imide to obtain a precursor solution; s3, pouring a proper amount of precursor solution into a polytetrafluoroethylene mould, paving, and polymerizing and crosslinking in a blast oven to form a film, thus obtaining the solid polymer electrolyte membrane.
  2. 2. The lithium-ion solid-state battery according to claim 1, wherein in step S1, the molar ratio of 3, 6-dioxa-1, 8-octanedithiol to triglycidyl isophthalonitrile urate is 1 to 3:1.
  3. 3. The lithium ion solid state battery of claim 1, wherein the mass ratio of N, N-dimethylformamide to 3, 6-dioxa-1, 8-octanedithiol is 25:3-1.
  4. 4. The lithium-ion solid state battery according to claim 1, wherein in step S2, the molar ratio of 3, 6-dioxa-1, 8-octanedithiol to lithium bis (trifluoromethylsulfonyl) imide is 3:2-1.
  5. 5. A lithium-ion solid-state battery according to claim 3, wherein in step S2, magnetic stirring is used, the rotational speed of the magnetic stirring is 1000-1500 rpm, the temperature is 50-100 ℃, and the time is 5-7 h.
  6. 6. The lithium-ion solid-state battery according to claim 1, wherein in step S3, the polymerization temperature is 60 to 80 ℃ and the polymerization time is 4 to 5 h.
  7. 7. The lithium ion solid state battery of claim 1, wherein the solid polymer electrolyte membrane has a thickness of 30-100 μm.
  8. 8. The lithium ion solid state battery of claim 1, wherein the positive electrode sheet is lithium iron phosphate LFP or nickel cobalt manganese NCM811.
  9. 9. A method of manufacturing a lithium-ion solid state battery according to any one of claims 1 to 8, wherein the lithium-ion solid state battery is assembled in the order of the negative electrode case, the lithium sheet, the polymer electrolyte membrane, the pole piece, the spacer, the spring sheet and the positive electrode case, and the assembled battery is packaged in a battery sealer.

Description

Lithium ion solid-state battery and preparation method thereof Technical Field The invention relates to the technical field of lithium metal solid-state batteries, in particular to a lithium ion solid-state battery and a preparation method thereof. Technical Field Solid state lithium metal batteries have higher energy density and superior safety compared to conventional liquid electrolyte lithium ion batteries, making them a potential candidate for future development of electric vehicles. The solid electrolyte is used as an important component of the solid lithium metal battery, and has great influence on the cycle stability and the service life of the solid lithium metal battery. Among the solid electrolytes, although the inorganic solid electrolyte has high ion conductivity and exhibits excellent thermal/chemical stability, poor interface contact may cause problems such as high interface resistance and non-uniform lithium ion transport, and the preparation cost of the inorganic solid electrolyte is high, which is difficult to be industrially applied. In contrast, solid polymer electrolytes exhibit good interfacial contact due to their high flexibility and processability. Solid polymer electrolytes, particularly polyether electrolytes, have been widely studied for their high ether group solvating ability and optimal chain spacing. However, the most commonly used polyethylene oxide has a high crystallinity and a high melting point, resulting in poor ionic conductivity and a low cation transfer number, which hinders its practical application in solid molecular films. Disclosure of Invention In view of this, in order to achieve the above object, the technical solution of the present invention is as follows: The lithium ion solid-state battery comprises a positive electrode plate, a solid polymer electrolyte membrane and a lithium metal negative electrode plate which are assembled together, wherein the solid polymer electrolyte membrane is prepared by the following method: s1, taking a proper amount of N, N-dimethylformamide, respectively adding 3, 6-dioxa-1, 8-octane dithiol and isocyanuric acid triglycidyl ester, and uniformly mixing to obtain a mixed solution; S2, adding lithium bis (trifluoromethyl sulfonyl) imide into the mixed solution, and adding a magneton on a magnetic stirrer to completely dissolve the lithium bis (trifluoromethyl sulfonyl) imide to obtain a precursor solution; s3, pouring a proper amount of precursor solution into a polytetrafluoroethylene die, paving, and polymerizing and crosslinking in a blast oven to form a film, thus obtaining the thioether crosslinked network type polymer electrolyte. Further, in the step S1, the molar ratio of the 3, 6-dioxa-1, 8-octanedithiol to the triglycidyl isophthalonitrile urate is 1-3:1. Further, the mass ratio of the N, N-dimethylformamide to the 3, 6-dioxa-1, 8-octanedithiol is 25:3-1. Further, in the step S2, the molar ratio of the 3, 6-dioxa-1, 8-octanedithiol to the lithium bis (trifluoromethylsulfonyl) imide is 3:2-1. Further, in the step S2, the rotating speed of the magnetic stirring is 1000-1500 rpm, the temperature is 50-100 ℃ and the time is 5-7 h. Further, in step S3, the polymerization temperature is 60-80 ℃ and the polymerization time is 4-5 h. Further, the thickness of the solid polymer electrolyte membrane is 30-100 μm. Further, the positive electrode plate is lithium iron phosphate LFP or nickel cobalt manganese NCM811. Based on the above scheme, a second object of the present invention is to provide a method for preparing a lithium ion solid-state battery as described above, wherein the lithium ion solid-state battery is obtained by assembling a negative electrode shell, a lithium sheet, a polymer electrolyte membrane, a pole piece, a gasket, a spring piece and a positive electrode shell in this order, and the assembled battery is packaged on a button cell sealing machine. Compared with the prior art, the invention has the following advantages: (1) Firstly, the solid polymer electrolyte membrane adopted by the invention is based on thiol-epoxy click chemistry reaction, and S atoms in thioether groups of 3, 6-dioxa-1, 8-octanedithiol have lone pair electrons which are used as nucleophiles to attack ternary rings of isocyanuric acid triglycidyl epoxy groups. The epoxy three-membered ring is opened by a nucleophile to generate a three-dimensional thioether crosslinked network structure. A large amount of weakly coordinated thioether groups can promote dissociation of lithium salts, producing a large amount of free Li +, increasing the amount of Li +. And secondly, the steric hindrance of the three-dimensional thioether crosslinked network crosslinked points can prevent ordered stacking of molecular chains, so that the crystallinity of the polymer is obviously reduced, the proportion of an amorphous region is enlarged, the segment movement capacity is improved, the activation energy of segment movement of an amorphous region is reduced,