Can Wood Byproducts Prevent Graphite Shortages in Li-ion Batteries?
Electric vehicles are critical to the collective shift toward cleaner and greener forms of transportation, but the graphite-based components of Li-ion batteries tax supply chains and the environment in myriad ways. Recycling wood byproducts might offer a renewable solution to the graphite supply problem.
The combustion engine car may be on its way out. The Environmental Protection Agency recently set stricter regulations to eliminate half of tailpipe emissions by 2032. The measure could result in electric vehicles (EVs) making up about 56% of all new vehicles.
But, some underestimate the environmental complexity associated with securing the materials needed to produce EV parts, particularly lithium-ion (Li-on) batteries. Graphite, commonly used for the battery anode, is a critical component of Li-ion battery manufacturing.
Both mining graphite and creating synthetic graphite have environmental drawbacks. However, one New Zealand firm has found a way to use scrap wood byproducts to synthesize graphite from a natural source. This process can dramatically cut down on wood waste while also preventing the use of fossil fuels needed for more traditional methods of securing the graphite supply required to support Li-ion production.
CarbonScape’s graphite production. Image used courtesy of CarbonScape
Rapidly Growing Graphite Demand
As the EV market grows, concerns about sustaining this growth also rise as the demand for materials like graphite outpaces the supply. Currently, 1.3 million metric tons of graphite are mined annually, but experts estimate that by 2030, it will take up to 6 million metric tons to supply the Li-ion manufacturing market.
Such a significant discrepancy between current rates of graphite production and future needs shows a clear challenge ahead. However, the means for meeting this demand are fraught with various challenges. Both mining and processing synthetic graphite present environmental challenges and supply chain obstacles.
Natural and Synthetic Graphite Production Challenges
Regardless of production methods, graphite demands a significant amount of energy, and there is no simple way to sidestep the challenges associated with mining natural graphite or synthesizing graphite.
Mined graphite must still undergo processing to meet the purity standards needed for Li-ion batteries. Hydrofluoric acid and sodium hydroxide are both required for this process, and if not managed carefully, they can easily compromise ecosystems, wastewater, groundwater, and runoff. In addition, calcined petroleum coke is used to “upgrade” mined graphite, so what some might consider a “natural” source ultimately relies on a coal-like product with its share of harmful effects.
The same calcined petroleum coke is also used to create synthetic graphite and other oil byproducts such as coal tar pitch. Creating synthetic graphite requires an intense heating process to reach 3,000°C. Coal powers these furnaces.
In addition, manufacturing infrastructure and political dynamics impact the supply chain significantly. Graphite remains the most important mineral for the production of Li-ion batteries, but there is only one graphite mine in North America. China controls 70% of the world’s synthetic and natural graphite supply. There is a fundamental need for a technological innovation that can spur graphite production forward in other corners of the world without compromising the renewable energy goals associated with Li-ion battery production.
The Biographite Alternative and Using Wood Waste to Create a Circular Economy
CarbonScape, a New Zealand firm working toward sustainable graphite alternatives, is pioneering a method for synthesizing graphite using wood chips. The product is called biographite.
Rather than relying on fossil-fuel-driven production methods, CarbonScape uses existing wood waste to create charcoal. This charcoal is then turned into graphite through a technique known as thermo-catalytic graphitization, which creates a crystalline structure.
Biographite from CarbonScape. Image used courtesy of CarbonScape
The company claims its biographite anode provides faster charging capacity than natural or synthetic graphite. Its microstructure permits lithium ions to move rapidly through the battery.
CarbonScape estimates it can meet 50% of the world’s graphite demand by 2030 using only 5% of the lumber industry's waste. Wood waste creates a significant carbon footprint, but for every ton of biographite produced, 2.7 tons of carbon will be removed from the environment.
As society pivots to carbon-free innovations, engineers must understand the complexity of how energy technologies can still impact the environment and create unique chemical and technological problems. Repurposing wood waste for graphite production will streamline support for EV market growth without compromising renewable energy goals.
