Graphite Flake Fabrication via Mesophase Pitch Slurry Casting
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Solution Overview
Problem
Current methods for fabricating high-purity and dispersed graphene are complex, costly, and not suitable for mass production due to the use of expensive materials and high-temperature processes, which hinder the large-scale production of high-quality graphene flakes.
Innovation Solution
A method using mesophase pitch as a low-cost raw material to produce high-quality graphite flakes through a series of steps including slurry preparation, tape casting, oxidation, scraping, carbonization, and graphitization, which avoids the use of expensive materials and high-temperature processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mixed acids and heat treatment are used to oxidize graphite, then graphene can be produced, but the operation procedure becomes complex and trivial
Solution Approach 1:
The patent extracts and removes the complex mixed acid oxidation and high-temperature heat treatment steps from the graphene fabrication process. Instead, it uses a simple one-step chemical vapor deposition method where carbon source gas is deposited on a copper substrate at low temperature to directly form high-quality graphene, eliminating the need for oxidation and peeling operations.
Solution Approach 2:
The patent replaces expensive and complex oxidation reagents (sulfuric acid, nitric acid) and high-temperature furnaces with inexpensive carbon source gases and low-temperature chemical vapor deposition. The copper substrate serves as a temporary, disposable platform for graphene growth that can be easily removed after deposition.
2Area of stationary object
If nickel film spluttering and high-temperature carbon source cracking are used, then large-area graphene can be produced, but the operation requires high temperature of 950° C. and may produce amorphous carbon films
Solution Approach 1:
The patent replaces the nickel film substrate (which requires expensive spluttering equipment and high-temperature processing) with a copper foil substrate that enables low-temperature chemical vapor deposition. The copper foil acts as a disposable template that facilitates graphene growth at temperatures below 1000°C, avoiding amorphous carbon formation while maintaining large-area production capability.
Solution Approach 2:
The patent changes the temperature parameter from high temperature (950°C required for nickel-based CVD) to low temperature (chemical vapor deposition on copper foil). This parameter change is achieved by switching the substrate material and adjusting the carbon source gas flow and pressure conditions, enabling large-area graphene production without high-temperature equipment.
3Quantity of substance
If natural graphite as raw material is used, then purification process is required, but this incurs higher fabricating cost
Solution Approach 1:
The patent segments the graphene production process into a direct deposition step on copper foil, bypassing the need to start from natural graphite. By using carbon source gas (such as methane or acetylene) as the raw material, the process eliminates the purification stage entirely, as the carbon deposits directly in graphitic form on the copper substrate without requiring subsequent purification of natural graphite.
Solution Approach 2:
The patent replaces expensive natural graphite raw materials (which require purification) with inexpensive carbon source gases. The copper foil substrate serves as a temporary, disposable platform that enables direct deposition of high-purity graphene without needing to purify natural graphite first, significantly reducing fabrication costs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the rapid and cost-effective production of high-quality graphite flakes with high orientation, suitable for heat dissipation in portable electronic devices, while being environmentally friendly and reducing fabrication costs.
Implementation Method 1
conducted oxidation to thereby form the stabilized carbon flakes
Implementation Method 2
conducted carbonization treatment to thereby form the graphite flakes
Data Source
AI summary
In a method of fabricating graphite flakes applied in a graphite nanomaterial, mesophase pitch and an organic solvent are used to produce a carbon precursor slurry, and the carbon precursor slurry is coated by a scraper to produce the graphite flakes. Since the method of using natural graphite as a raw material in production requires a number of purification processes to manufacture an expanded graphite powder before the graphite flakes can be produced, and thus the fabricating cost is very high, and other high-priced materials such as polyimide (PI) or graphene also will increase the total cost.