A method for the continuous exfoliation of graphene based on electrostatic repulsion

Abstract

The invention belongs to the technical field of preparation processes of graphene materials and particularly relates to a method for preparing graphene by continuous peeling on the basis of electrostatic repulsive force. The process comprises the following steps: multiple layered crystalline graphene materials, an ammonium source, a lithium source, strong alkali and water are mixed into alkali graphene slurry under the conditions of mechanical stirring and ultrasonic treatment; the alkali graphene slurry is sprayed out through a high-pressure atomizing nozzle provided with a point corona device to form an atomized shape, simultaneously the atomized slurry particles are treated by corona, negative charges are quickly gathered on the surfaces of graphite particles, burst occurs when the electrostatic repulsive force among the charges is larger than the interlayer van der waals force of the graphite particles, after collection, inorganic ions are removed by filtering and washing and then the graphene is obtained. In the method, the oxidation treatment process is avoided, and the graphite is peeled into one or more layers of graphene by high yield. The method can be scaled up to industrial production. Compared with other graphene preparation processes, the method has the advantages that the produced graphene sheet is fewer in defect and higher in electrical property, mechanical property and hydrophobic property.

Description

technical field [0001] The invention belongs to the technical field of graphene material preparation technology, and in particular relates to a method for preparing graphene by continuous exfoliation based on electrostatic repulsion. Background technique [0002] Carbon material is a common and special material on the earth. It can form diamond with higher hardness and soft graphite. In the past 20 years, carbon nanomaterials have been the frontier of scientific and technological innovation. In 1985, the rich Both Leene and the carbon nanotubes discovered in 1991 caused great repercussions, and a research boom arose. In 2004, Geim's group at the University of Manchester first obtained a single-layer or thin-layer two-dimensional atomic crystal-graphene by mechanical exfoliation. . The discovery of graphene has enriched the family of carbon materials, forming a complete system from zero-dimensional fullerenes, one-dimensional CNTs, two-dimensional graphene to three-dimension...

AI Technical Summary

Problems solved by technology

The mechanical exfoliation method is a simple and feasible method that can produce high-quality graphene at low cost. However, in order to improve the exfoliation effect during the mechanical exfoliation process, organic solvent intercalation is usually introduced, although it can improve the intercalation reaction to a certain extent. Efficiency and control of particle distribution, but the solvent residues in graphene are not easy to remove and easily cause product contamination

Moreover, the existing mechanical stripping efficiency is low; in addition, the strong pressure of the grinding medium will cause the graphite layer structure to become more compact, which will lead to a decrease in the stripping effect, resulting in long grinding time and very high costs; moreover, the current grinding production of graphene is intermittent. While exfoliating graphite, the exfoliated graphene cannot be screened out in time, so it is difficult to carry out continuous and stable mass production, and it is difficult to carry out large-scale industrial production

The arc discharge method mainly uses graphite rods as raw materials. The graphene prepared by the arc method is large in size. When used as the anode material of lithium ion batteries, the migration path of lithium ions is long, the charge and discharge performance is not good, and the output is difficult to meet the needs of industrial applications.