January 2, 2025 - RNL scientists have developed two methods to convert coal into graphite, a critical mineral used in EV batteries. 

With limited domestic graphite supplies and dependence on foreign imports, this initiative aims to boost EV adoption, reduce reliance on foreign materials, and revitalize coal mining communities. 

The project involves optimizing graphite production, ensuring economic viability, and scaling for manufacturing. 

“Lithium and cobalt are two critical minerals in batteries that grab all the headlines, but the biggest material by weight in the EV battery is graphite,” said Eric Wolfe, an engineer at ORNL. 

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  Two routes for coal-to-graphite conversion

  ORNL researchers are exploring two ways to transform coal into graphite. One uses coal char, a solid byproduct, while the other utilizes coal liquids. By heating coal without oxygen, researchers create both char and liquids. One team treats the liquid byproduct to make particles, while another converts the particles or char into graphite within an electrochemical reactor.
  
  
   
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  ORNL's electrochemical graphite production

  ORNL's electrochemical process creates graphite from coal byproducts at 1,500 degrees Fahrenheit. This contrasts with the conventional method, which requires temperatures over 4,000 degrees Fahrenheit. The conversion occurs when 2.7 volts are applied to an electrochemical reactor. Ions travel through molten salts between electrodes.
  
  
   
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  Improving graphite for EV battery performance

  ORNL researchers adapted an industrial process to spray a mixture of coal liquids and a solvent through a nozzle. Pressurized air evaporates the solvent, solidifying the pitch into spherical particles. This shape improves flow during battery manufacturing and ion movement within the battery. This method allows for precise particle size control without material waste, which is crucial for creating the tiny particles needed in lithium-ion batteries.
  
  
  

   

  Coal mining waste transformed into graphite

  ORNL's electrochemical process utilizes coal mining waste to create graphite. By heating coal granules in a process called pyrolysis, researchers produce coal char and coal liquids, which are then converted to graphite using a benchtop electrochemical process. This method effectively transforms waste into a valuable material for battery anodes.
   
  

   

  Efficient and cost-effective graphite production

  A preliminary techno-economic analysis concluded that the new process could be less expensive than conventional methods of making graphite. The new process would cost about 13% less than the cost of the conventional Acheson process, which ranges from $7 to $20 per kilogram. Moreover, ORNL’s method takes only hours instead of 3 to 6 days.
   
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  Developing coal-to-graphite technology

  ORNL partnered with the University of Kentucky and Ramaco Carbon to develop and commercialize its coal-to-graphite technology.  Ramaco Carbon supplies coal and is exploring commercialization, including building a pilot production facility.  They are also experimenting with graphite production from char in their Wyoming lab and exploring manufacturing near their Appalachian mines.
  
  
  

   

  Revitalizing coal communities through graphite production

  ORNL's coal-to-graphite project aims to revitalize coal communities by creating new jobs and promoting environmental sustainability. ORNL plans to share study results with battery and equipment manufacturers, enabling them to license the technology and establish production facilities in coal regions. This could lead to the manufacturing of both graphite and batteries, further boosting local economies.