Research by NETL and its partners is advancing discoveries to produce graphite — a material whose unique properties make it an essential component for mass-producing battery electric vehicles (BEVs), energy storage systems and other green technologies — from unwanted carbon waste materials.

As the nation undergoes a transformational shift to a clean energy economy, demand for graphite has soared; however, the highly offshore nature of graphite supply chains has created price volatility. According to researchers at NETL and the Oak Ridge National Laboratory (ORNL), the price of graphite that the United States imports for synthetic graphite electrodes increased by more than 400% between 2016 and 2018, while the cost for other types of graphite imports rose by 100%-300% in the same time period.

NETL and ORNL research is addressing these challenges by developing new methods to manufacture graphite and create a reliable domestic supply chain. “Our work is showing that coal, coal waste and other unconventional materials are exceptional feedstocks for making high-quality graphite materials suitable for battery and other high-performance applications,” said NETL’s Joseph Stoffa, technology manager, Carbon Ore Processing.

A novel process developed by NETL researchers focuses on using abundant catalyst materials, such as iron, to facilitate the production of highly crystalline graphite. Coal of different ranks, coal waste, coal char and plastic waste have been demonstrated to work as feedstocks with this process. The catalyst used in this method is responsible for dropping process temperatures from 3,000 °C down to 1,500 °C and reducing process times from several days to just a few hours.

Additionally, the research demonstrates the catalyst can be recovered, recycled and reused, indefinitely, which improves the overall economics and environmental footprint of graphite production. The graphite produced with this process has been tested as a battery anode and has been shown to outperform anodes made with commercially sourced graphite materials.

A separate research effort at ORNL, supported by NETL, utilizes an electrochemical reactor to synthesize graphite directly from coal char. This process is unique because it allows low-value carbon feedstocks that typically are considered “non-graphitizable” to be converted directly into high-value graphite materials. The electrochemical reactor significantly reduces process temperatures and time, which improves the overall carbon footprint of the graphite manufacturing process.

Graphite is commonly used in batteries, steelmaking, aluminum production, refractories and lubricants. It has a particularly central role for renewable and low-carbon energy technologies, where it is used in modular nuclear reactors, advanced composites, bipolar plates for fuel cells and flow batteries, anodes for lithium-ion batteries, electrodes for supercapacitors and high-performance thermal management.

According to NETL researchers, demand for graphite is expected to increase by more than 2,000% between now and 2040 because of its use in lithium-ion batteries and BEVs.

“Graphite is listed as a critical mineral in the United States because of its broad use in manufacturing and the limitations caused by its offshore supply chain. NETL and our partners at ORNL are developing new approaches to produce the graphite needed for U.S. manufacturing and to preserve the environment for future generations,” Stoffa said.

NETL is a U.S. Department of Energy national laboratory that drives innovation and delivers technological solutions for an environmentally sustainable and prosperous energy future. By using its world-class talent and research facilities, NETL is ensuring affordable, abundant, and reliable energy that drives a robust economy and national security, while developing technologies to manage carbon across the full life cycle, enabling environmental sustainability for all Americans.