In 2024, University of Chicago researchers turned discarded bio-oil char into graphite; 8 hours of cooling made crystals 5 times thicker and over 15 times wider

Most phone, laptop, and electric-vehicle batteries rely on graphite, a material the United States does not currently produce domestically. In 2024, researchers at the University of Chicago discovered a way to offset some of this graphite shortfall by turning plant waste into high-quality graphite. The team's discovery came after they slowly cooled the material over about 8 hours instead of 3, resulting in crystals about 5 times thicker and about 15 times wider than in previous attempts.

According to the University of Chicago Pritzker School of Molecular Engineering, the discovery could have major implications for how the United States sources one of its heaviest import-dependent materials. It affects the supply chains for electric vehicles, laptops, and power banks we use daily.

Why the US has a graphite problem


Graphite helps a battery's anode store and release charge; without it, batteries in phones, laptops, and electric vehicles would not work. According to the U.S. Geological Survey, there was no domestic graphite mined in the United States in 2025. Graphite is also one of the materials the government designated as a critical mineral on the USGS 2025 List of Critical Minerals because of its importance in modern technologies and its vulnerability to supply chain disruption. This makes manufacturers reliant on imports to keep battery production going. With a domestic, plant-based alternative, the U.S. would have an option it does not currently have, and that is what the UChicago team set out to create.

Turning throwaway plant char into a high-tech material

Most graphite today is extracted from nature at the expense of the landscape or synthesized from crude oil, both of which have a heavy carbon footprint. Scientists have previously tried to create graphite from plant matter, but the resulting product has been too disordered and low-quality for practical electronics. Stuart Rowan, a professor at UChicago Pritzker Molecular Engineering and Argonne National Laboratory, and his collaborators started the process with a different material. They used biochar, the residue from producing bio-oil fuel. This carbon-rich material has a higher carbon content than raw plant matter, giving it an advantage over previous attempts to create graphite. The team has also used a common element, iron, to help turn the chaotic carbon into the hexagonal pattern of the desired material. The process required some trial and error, but the team discovered that the key to making it work is cooling the material.

How cooling time improved the graphite

Rowan's team cooled the mixture for eight hours, up from the roughly 3-hour standard timeframe, so that carbon atoms would have sufficient time to arrange themselves in ordered patterns on the surface of iron particles. As a result, the crystal structures formed were five times thicker and more than 15 times wider than those obtained from the standard procedure. The researchers also calculated and compared their process with different methods for making graphite from biomass, as well as conventional graphite mined from natural sources or produced through other synthetic methods. The team found the bio-based alternative was superior in terms of both fossil fuel consumption and greenhouse gas emissions.

Putting the new graphite to a real test

A promising result on paper means little if the material performs poorly in practice. So far, that test has focused on printed electronics rather than battery cells themselves: the researchers produced graphene inks used to print sensors and simplified electronic circuits. They found that inks made from their bio-graphite conducted electricity better than similar inks made from other types of bio-graphite and worked in actual electronics. The project, named MADE-PUBLIC, was supported by the National Science Foundation's Future Manufacturing Program and conducted in collaboration with Northwestern University and the University of Illinois Urbana-Champaign.

A homegrown fix still years from your battery

The team's work is far from over. According to the researchers, to truly harness this material for batteries rather than printed electronics, they'll need to grow even larger chunks of graphite and lower production costs as they scale up. Those are among the main challenges before battery manufacturers could adopt the material at commercial scale. If that happens, the benefits would extend beyond a single lab. It would create a domestic supply of a material that is currently unavailable in the U.S. for companies looking to make advanced batteries from what is essentially waste material. For now, the research shows how to take something currently considered an unusable byproduct and turn it into valuable, high-tech material that could become part of the everyday lives of millions of Americans who charge their devices overnight.