Preparation method of graphene sheet

A graphene flake and graphite technology, applied in the field of graphene flake preparation, can solve problems such as difficulty in obtaining graphene materials, low yield, detachment of graphite fragments and the like

Active Publication Date: 2015-12-16
HEFEI UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process has the problem of low yield. The graphite fragments that are peeled off are easy to detach from the graphite electrode, which stops the peeling reaction and makes it difficult to obtain graphene materials.

Method used

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  • Preparation method of graphene sheet
  • Preparation method of graphene sheet

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] 1) Electrolyte configuration

[0027] In the glove box, a certain amount of hexafluorophosphoric acid (LiPF 6 ) into the propylene carbonate (PC) solution, shake well until the lithium salt is completely dissolved, and the concentration is 1mol / LLiPF 6 / PC electrolyte.

[0028] 2) Evenly disperse 2g of graphite in the reaction vessel, and drop a certain amount of 1mol / LLiPF under the protective atmosphere of argon 6 / PC electrolyte, add a certain amount of metal lithium flakes into it and stir, and after a period of reaction, expanded graphite can be obtained, such as figure 1 , figure 2 Shown are the optical micrographs of expanded graphite reacted for 2h and 4h respectively. Disperse the exfoliated expanded graphite in an alcohol solution and separate to obtain graphene flakes, such as image 3 , Figure 4 Shown are TEM pictures of graphene flakes reacted for 2h and 4h, respectively.

Embodiment 2

[0030] Repeat Example 1, the difference is that step 1) electrolyte is 0.5mol / LLiI / PC-DMC (1:1, wt), step 2) graphite and binder polyvinylidene fluoride (PVDF) are mixed by mass Mix and add appropriate amount of N-methylpyrrolidone (NMP) at a ratio of 92:8 to adjust it into a uniform slurry with certain fluidity. Coat the slurry on the pre-cleaned substrate (choose the thickness according to the need), and place it in a constant temperature oven at 60°C for 4-5h, and then transfer it to a vacuum oven at 60°C to dry for 2h, in order to completely volatilize NMP . The copper foil coated with the active material was wrapped with sulfuric acid paper (to prevent contamination), compacted with a roller press, and then dried in a vacuum oven at 60 °C for 2 h.

Embodiment 3

[0032] Repeat Example 1, the difference is that the electrolyte used in step 1) is 1.2mol / LLiTFSI / DMSO.

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Abstract

The invention discloses a preparation method of a graphene sheet. The graphene sheet is prepared from graphite and alkali metal through electrochemical reduction exfoliation of the graphite in a short-circuit-resembling environment under the condition of a nonaqueous electrolyte as an intercalation agent. The preparation method has the benefits as follows: oxidizing raw materials such as strong acid and the like are not used, the graphite is mixed with the alkali metal directly in the electrolyte and exfoliated in an short-circuit-resembling electrochemical environment, the operation is simple, an exfoliation product is in the electrochemical environment all along, and the graphene sheet material with sufficient exfoliation is obtained more easily; further, the method is amplified easily for macroscopic preparation, and the prepared graphene sheet have complete structure, fewer defects, good homogeneity and good electrical conductivity.

Description

technical field [0001] The invention relates to a method for preparing graphene flakes, and mainly relates to the technical field of graphene preparation. Background technique [0002] Graphene is a graphite sheet composed of a single layer of carbon atoms. It has excellent electrical conductivity and thermal stability, and has been widely used in catalysis, energy storage and other fields. At present, graphene can be prepared by various methods, such as mechanical exfoliation method, oxidation-reduction method, crystal epitaxial growth method, chemical vapor deposition method, organic synthesis method and exfoliated carbon nanotube method, but these methods are complicated in process and high in production cost , serious pollution, and the prepared graphene often has more surface defects and oxygen-containing functional groups. Electrochemical exfoliation of graphite is a fast, simple and feasible method for the preparation of new thin-sheet carbon materials (graphene nano...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B31/04
Inventor 项宏发石鹏程
Owner HEFEI UNIV OF TECH
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