Methods for Preparing Graphene Powder

Overview: A method for preparing graphene powder includes the following steps:

1. Reduction pre-treatment of flake graphite.
2. Adding lithium and liquid ammonia to the pre-treated graphite flakes.
3. Achieving efficient liquid-phase dissolution of graphene, increasing the graphene yield by over 40% compared to untreated graphite.

Here are some specific methods for preparing graphene powder:

1. Reduction Pre-treatment Method:

• Step 1: Reduce and pre-treat flake graphite.
• Step 2: Add lithium and liquid ammonia to the pre-treated graphite flakes.
• Step 3: Achieve liquid-phase dissolution of graphene. This method enhances the efficiency of graphene production by over 40% compared to untreated graphite.

2. System for Preparing Graphene Powder for Carbon Nanotube Slurry:

• Components: Grinding device, conveying device, drying device.
• Drying Device: Includes a drying cylinder with a guiding plate arranged spirally inside.
• Process:
  • Heat is supplied via an electric heater and fan.
  • Graphene powder is rolled down the guiding plate, increasing drying time.
  • A water tank with a pump supplies water through pipes, aiding in the drying process.

3. Liquid Phase Ball Milling Method:

• A liquid-phase ball milling process is used to exfoliate graphite into graphene.

4. Optimized Production of Three-Dimensional Graphene Powder:

• Steps:
  • Sensitize polymers with treatments like alkalization, acidification, metal ion exchange, and pore formation.
  • Dry the sensitized material.
  • Pyrolyze the dried material.
  • Disintegrate the pyrolyzed sample in a solvent.
  • Perform metal recovery on the disintegrated sample.

5. Graphene Preparation with Lithium and Liquid Ammonia:

• Steps:
  • Pre-treat graphite flakes.
  • Add lithium and liquid ammonia.
  • After liquid ammonia evaporates, add water or dilute acid and perform ultrasonic treatment to achieve liquid-phase exfoliation of graphene.

6. Graphene and Its Applications:

• Steps:
  • Disperse graphite flakes uniformly in a medium to obtain a dispersion.
  • Mix the dispersion uniformly using a mixing device.
  • Physically exfoliate the mixed dispersion to obtain a coarse graphene product.
  • Pass the coarse product through a high-pressure micro-jetting device for further processing.
  • Subject the graphene slurry to physical precipitation or centrifugation to obtain stable graphene slurries of different grades.
  • Dilute, wash, and dry the graphene slurry repeatedly to obtain graphene powder.

These methods highlight various techniques and processes used to prepare high-quality graphene powder, focusing on improving yield, efficiency, and scalability for industrial applications.