Upgraded Coal Graphitization for Low-Ash Battery-Grade Graphite
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Solution Overview
Problem
Natural coal sources, particularly low-rank coals, have undesirable properties such as low fixed carbon concentration, high oxygen content, and high ash content, making them unsuitable for energy generation and graphene production, and the demand for graphite for lithium-ion batteries exceeds the supply of natural graphite resources.
Innovation Solution
A method involving the carbonization and graphitization of upgraded coal, where coal is cleaned and treated with oxidizable inorganic metallic agents or reducing agents to reduce ash and oxygen content, followed by heating in an inert environment to produce carbonized upgraded coal with high fixed carbon content, which is then graphitized to form high-quality graphite.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If natural graphite resources are used to meet growing demand, then graphite supply can be maintained, but natural graphite resources are becoming increasingly scarce and unable to meet rapidly growing demand
Solution Approach 1:
The patent substitutes expensive, scarce natural graphite with synthetic graphite produced from abundant, low-cost coal resources. The synthetic graphite is manufactured through carbonization and graphitization processes that convert coal into graphite with comparable properties, effectively replacing depleting natural resources with artificially produced materials.
Solution Approach 2:
The patent transforms coal into graphite by changing its physical and chemical parameters through controlled heating processes. The carbonization process converts coal's molecular structure at 500-700°C, followed by graphitization at 2500-3000°C to achieve the crystalline structure of graphite, fundamentally altering the material parameters to meet demand.
2Ease of manufacture
If low-rank coal is used directly for energy generation or graphene production, then processing costs are reduced, but the coal has low fixed carbon concentration, high oxygen concentration, and high ash content making it less suitable
Solution Approach 1:
The patent applies preliminary upgrading treatments to coal before carbonization to improve its quality. This includes cleaning processes to remove impurities and chemical treatments to adjust the coal's composition, ensuring the feed material has optimal properties for subsequent graphitization and producing high-quality graphite output.
Solution Approach 2:
The patent modifies coal's chemical composition parameters through upgrading processes that reduce oxygen content and ash content while increasing fixed carbon concentration. These parameter changes transform low-rank coal into a suitable feedstock for graphite production, bridging the gap between raw coal quality and final product requirements.
3Manufacturing precision
If multi-stage heating process is applied to carbonize upgraded coal, then graphite quality is improved, but process complexity and energy consumption increase
Solution Approach 1:
The patent divides the graphite production process into distinct stages: cleaning, carbonization at 500-700°C, and graphitization at 2500-3000°C. Each stage has specific objectives and controlled parameters, allowing systematic optimization of graphite quality while managing process complexity through modular, sequential operations.
Solution Approach 2:
The patent exploits phase transitions of carbon during heating to achieve graphitization. The controlled heating process induces structural transformations from amorphous carbonized coal to crystalline graphite at high temperatures, using thermal energy to drive the phase change that creates the desired material properties.
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
The method produces graphite with a high carbon content and controlled ash levels, suitable for lithium-ion batteries and other applications, offering a cost-effective and efficient alternative to traditional graphite sources.
Implementation Method 1
heating the upgraded coal in an inert environment, to form a carbonized upgraded coal
Implementation Method 2
graphitizing carbonized upgraded coal, to form the graphite
Data Source
AI summary
A method of forming graphite includes carbonizing an upgraded coal, to form a carbonized upgraded coal. The method also includes graphitizing the carbonized upgraded coal, to form the graphite.