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EP-4741343-A1 - METHOD FOR PRODUCING DOPED GRAPHITE FLAKES

EP4741343A1EP 4741343 A1EP4741343 A1EP 4741343A1EP-4741343-A1

Abstract

The present disclosure provides a method for manufacturing doped graphite flakes. According to one embodiment of the present disclosure, the graphite flakes can be manufactured economically by feeding a doping source together with an inert gas through air jet milling when manufacturing the graphite flakes. The doped graphite flakes manufactured by the method according to one embodiment of the present disclosure can be applied to various fields, including petrochemicals, cosmetics, pharmaceuticals, batteries, etc.

Inventors

  • HONG, BYUNG HEE
  • KIM, DONG JIN
  • PARK, JONG BO

Assignees

  • Seoul National University R&DB Foundation
  • Graphene Square Inc.
  • Graphene Square Chemical Inc.

Dates

Publication Date
20260513
Application Date
20240704

Claims (7)

  1. A method for manufacturing doped graphite flakes, the method comprising steps of: preparing graphite raw materials; and pulverizing the graphite raw materials using an air jet mill, wherein the pulverizing step is performed while feeding a mixed gas of an inert gas and a dopant source gas.
  2. The method of claim 1, wherein the dopant source gas is one or more selected from ammonia (NH 3 ), hydrazine (NH 2 NH 2 ), pyridine (C 5 H 5 N), acetonitrile (CH 3 CN), triethanolamine (C 6 H 15 NO 3 ), and aniline (C 6 H 7 N)
  3. The method of claim 1, wherein the inert gas and the dopant source gas in the mixed gas have a mixing volume ratio of 1:0.001 to 1:1000.
  4. The method of claim 1, wherein the mixed gas has a feed rate of 0.1 to 1,000 standard cubic centimeter per minute (SCCM).
  5. Doped graphite flakes which are manufactured by the method according to any one of claims 1 to 4, and have a dopant content of 0.01 vol% to 30 vol%.
  6. The doped graphite flakes of claim 5, having an average particle diameter of 0.01 to 100 µm.
  7. The doped graphite flakes of claim 5, wherein the dopant is one or more selected from -NH 2 , -NHNH 2 , -C 5 H 4 N, -CH 2 CN, -C 6 H 14 NO 3 , and -C 6 H 6 N.

Description

Technical Field The present disclosure claims the benefit of Korean Patent Application No. 10-2023-0086576, filed with the Korean Intellectual Property Office on July 4, 2023, the entire contents of which are incorporated in the present disclosure. The present disclosure relates to a method for manufacturing doped graphite flakes. Specifically, the present disclosure relates to a method that can manufacture doped graphite flakes simply and effectively. Background Art Graphite is a chemically considerably stable material having a shape in which rings composed of six carbons are connected to form layers, and graphite has strong heat resistance, thermal shock resistance and corrosion resistance, and good electrical and thermal conductivity. In particular, graphite flakes are used as various electrode materials for secondary batteries, electrolysis devices, etc. and raw materials for heat-resistant devices, etc. Graphite flakes can be manufactured by pulverizing graphite raw materials by a mechanical or chemical method. The mechanical method includes air jet milling, which is a method of using high-pressure compressed air in an air jet mill device to pulverize the sample. Specifically, the graphite raw materials fed into the air jet mill from the feed hopper are transported to the center of the inside of air jet mill by air injected at high pressures from the compressor nozzle are pulverized by interactive self-collision. The powder pulverized in the internal air jet mill is automatically classified to the desired particle size by a classifier installed at the top of the air jet mill and moved to the collection unit. Meanwhile, when pulverizing graphite using air jet milling, it can be performed under an inert gas or halogen gas atmosphere, such as high-pressure helium (He), argon (Ar), or nitrogen (N2). This is because milling in an air atmosphere can oxidize graphite. Meanwhile, since conventional mechanical pulverizing simply aims to pulverize the graphite raw materials, it is necessary to improve the electrical properties of the graphite flakes through additional processes. For example, since, after manufacturing graphite flakes, a doping process must be additionally performed through a chemical vapor deposition method using amine compounds, a hydrothermal reaction method, and other chemical reactions, or plasma treatment, there are economic and time-related disadvantages in terms of mass production. DISCLOSURE Technical Problem A technical object to be achieved by the present disclosure is to provide a method capable of economically manufacturing doped graphite flakes by simultaneously performing pulverization and doping of graphite raw materials. Technical Solution According to one aspect of the present disclosure, there is provided a method for manufacturing doped graphite flakes, the method including steps of: preparing graphite raw materials; andpulverizing the graphite raw materials using an air jet mill,wherein the pulverizing step is performed while feeding a mixed gas of an inert gas and a dopant source gas. According to another aspect of the present disclosure, there are provided doped graphite flakes which are manufactured by the method described herein, and have a dopant content of 0.01 vol% to 30 vol%. Advantageous Effects According to a manufacturing method according to one embodiment of the present disclosure, doped graphite flakes can be mass-produced through a simple process. Brief Description of Drawings FIG. 1A is a partial schematic drawing of an air jet mill device usable in a manufacturing method according to one embodiment of the present disclosure.FIG. 1B is a schematic drawing of a pulverization unit of the air jet mill device usable in the manufacturing method according to one embodiment of the present disclosure.FIG. 1C is a cross-sectional schematic drawing of the pulverization unit of the air jet mill device usable in the manufacturing method according to one embodiment of the present disclosure.FIG. 2 is a photograph of an air jet mill used in the manufacturing method according to one embodiment of the present disclosure.FIG. 3 is SEM photographs and graphs showing the particle sizes and size distributions of graphite flakes manufactured by a manufacturing method according to Reference Example 1 of the present disclosure.FIG. 4 is Raman spectra of graphite flakes manufactured by the manufacturing method according to Reference Example 1 of the present disclosure.FIGS. 5A to 5H are FT-IR spectra of doped graphite flakes manufactured by manufacturing methods according to Examples 1 to 6 and Comparative Example 1 of the present disclosure. Best Mode for Carrying Out the Invention When a part in the present specification is said to "include" a component, unless otherwise specifically stated, this means that other components are not excluded, but the other components may be further included. Hereinafter, the present disclosure will be described in more detail with reference to the dr