C. Matranga
National Energy Technology Laboratory,
United States
Keywords: graphite, critical minerals, battery, energy storage, materials, carbon, electric vehicles
Summary:
Global graphite production currently exceeds ~4 million metric tonnes per year with roughly ¾ of this occurring for synthetic graphite and the balance for natural graphite. Graphite demand is expected to grow in coming years driven, in part, by use of graphite for electric vehicle batteries. As graphite production increases, the impacts of manufacturing this material will also grow. For example, synthetic graphite production is an incredibly energy intensive and technically demanding process that involves heating a high-quality carbon coke up to ~2800 C, for several days. Methods that reduce the energy intensity of this process can potentially reduce greenhouse gas emissions and processing costs. Research conducted at the U.S. Department of Energy’s National Energy Technology Laboratory demonstrates that an Fe-based catalytic graphitization method can produce highly crystalline graphite from carbon chars and cokes at process temperatures between 1300-1500 C and process times of only a few hours. This method works with polyethylene-, biomass-, petroleum-, and coal- based char and coke and only requires modest adjustments to the catalytic graphitization step to accommodate different feedstocks. Additionally, the Fe-catalyst can easily be separated from the graphite product, recovered, regenerated, and re-used in the catalytic graphitization process. This approach offers opportunities to reduce the energy footprint and costs of graphite production and expand the range of feedstocks utilized to make this critical material.