N.T Huynh, KJ Kim, TD Nguyen, Y. Gao, B. Gita, Y. Li, V.H Pham, C. Wang, C. Matranga
National Energy Technology Laboratory,
United States
Keywords: crystalline graphite, lithium-ion batteries, recycle catalyst of graphitization
Summary:
Graphite is designated as a critical mineral because of its essential applications in the aerospace and energy sectors. Graphite is traditionally synthesized from a petroleum-derived needle coke using an energy-intensive and time-consuming process. These characteristics of graphite use, supply chains, and production illustrate the need to explore alternative feedstocks and manufacturing processes for graphite production. We will present a strategy for synthesizing highly-crystalline graphite powder from coal using a Fe2O3-catalyzed graphitization process. In this strategy, the use of a catalyst dropped the processing temperatures to 1500 °C and processing times to a few hours. The graphite produced using this process was characterized and shown to have comparable physical and chemical properties to commercially sourced graphite materials. We will also present a method that recovers and reuses the catalyst and acid used to retrieve them, thereby implementing a closed-loop chemical process. When the lithium-ion battery anode is fabricated with a series of graphite, all the graphite anodes show a consistent capacity and initial Coulombic efficiency and retain their electrochemical performance over 100 cycles. This work highlights the underutilized value of coal as a carbon feedstock, contributing to resource diversification and domestic supply resilience in support of the global energy transition.