Korea unlocks domestic graphite supply: From waste byproducts to high-performance battery anodes
The Korea Institute of Energy Research (KIER) has announced the development of a new technology that produces high-purity graphite anodes for lithium-ion batteries by utilizing domestic graphite byproducts.
image: Process flow of the developed technology
Credit: Korea Institute of Energy Research (KIER)
A KIER research team led by Dr. Yu-Jin Han and Dr. Sang-Hoon Park has developed a core technology to refine industrial graphite byproducts into high-purity anode materials for lithium-ion batteries, a breakthrough that could greatly lessen reliance on imported graphite.
Graphite, the essential raw material for lithium-ion battery anodes in electric vehicles, makes up about 30% of cell weight and 10% of production cost. Yet Korea relies on China for over 90% of its supply, creating risks of price surges and unstable availability amid global uncertainties.
Uncertainty became evident last July, when the U.S. Department of Commerce imposed steep tariffs on Chinese graphite used in anode materials, heightening concerns about future supply stability.
In response, the team developed a core technology to transform domestic industrial byproducts into high-value anode materials. Their new impurity-removal method simplifies conventional steps and enables the production of graphite anodes with cost competitiveness on par with commercial materials.
Producing high-purity anodes from graphite byproducts requires the complete removal of metallic impurities. Current methods rely on harsh acid treatment and heat processing above 2,000 °C, leading to environmental pollution and high costs that undermine economic viability. In addition, limited research on removing impurities within graphite raises doubts about the performance of recycled materials.
To address these challenges, the research team developed a multi-step process consisting of surface impurity removal through ultrasonic treatment, internal metallic impurity removal, and structural restoration through pyrolytic carbon coating. First, by using an ultrasonic reactor, they caused lighter impurities to float while heavier graphite particles settled, thereby removing surface impurities.
Next, by utilizing thermal migration and segregation phenomena, the team induced the residual metallic impurities within the graphite to migrate to the surface, where they were converted into oxides and made easier to remove. In the final step, they applied a carbon coating to the graphite surface, significantly enhancing structural stability and electrochemical performance. This approach enables effective impurity removal at lower temperatures than conventional methods, thereby achieving both economic efficiency and environmental friendliness.
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* Thermal migration and segregation phenomena: During heating, residual impurities within metals or ceramics migrate outward and accumulate on the surface, where they are converted into metal oxides. |
The graphite anodes produced with the developed technology achieved an initial coulombic efficiency of 92% and a discharge capacity of 362 milliampere-hours per gram (mAh/g), comparable to that of commercial graphite anodes. Furthermore, even after 200 charge–discharge cycles, they retained 98% of their initial capacity, demonstrating stability on par with commercial materials.
The economic analysis also revealed clear advantages. While producing commercial graphite anodes typically requires high-temperature heat treatment above 2,800 °C, consuming vast amounts of energy, the newly developed technology can reduce production costs by about 60% compared to conventional methods. The research team is also pursuing follow-up studies to develop a next-generation process that eliminates the need for both heat treatment and acid treatment.
“Our work shows that graphite, once left out of localization efforts, is now emerging as a national critical mineral,” said Dr. Yu-Jin Han, lead researcher. “By turning domestic byproducts into high-value anodes, this technology strengthens supply stability and builds a foundation for self-sufficiency.”
This research was published in the July 2025 issue of the Chemical Engineering Journal (Impact Factor 13.2), one of the world’s leading journals in chemical engineering and materials science. The work was supported by the Ministry of Trade, Industry and Energy and the Korea Evaluation Institute of Industrial Technology (KEIT) under the project “Development of Recycling Technology for Anode Materials from Used Batteries through Sorting and Purification,” led by Principal Researcher Ilchan Jang of KIER’s Gwangju Clean Energy Research Center.