Researchers at the Department of Energy’s Oak Ridge National Laboratory have developed ground-breaking techniques for formulating, manufacturing and recycling the lithium-ion batteries used in hundreds of products, including electric vehicles. New technologies patented by ORNL researchers are ready for private companies to license and commercialize.
ORNL is uniquely positioned to help drive decarbonization through innovative energy storage with its DOE Battery Manufacturing Facility, or BMF, the country’s largest open-access battery manufacturing research and development center. BMF labs can analyze and improve every stage in a battery’s lifespan, from raw materials to performance testing to recycling. The facility’s research enhances U.S. supply chain options, improves battery life and performance and reduces battery size and cost.
Recent inventions by ORNL battery engineers have particular significance and commercialization potential. One set of patented innovations focuses on direct recycling of electric vehicle batteries. Another offers a new way to formulate and produce these batteries without using the rare metal cobalt.
Batteries consist of positive and negative electrodes, called cathodes and anodes, which exchange electrons to create a current. The current is then collected and directed to perform work such as running an engine.
One of the most difficult steps in battery recycling is separating the thin metal electrode layers from the current collector. To the limited extent these are recycled today, the most common techniques involve smelting battery materials or dissolving them in acid. These approaches are expensive and potentially polluting and require chemical processes to separate the components of a liquid slurry.
Direct recycling is a physical separation process that allows reuse of the cathode and anode metals without much additional retreatment. “No company is doing direct recycling today,” said Ilias Belharouak, who heads the electrification section and BMF in the Energy Sciences and Technology Directorate at ORNL. “To my knowledge, our technology is one of the most significant advancements we have seen in direct recycling. It is less energy intensive, more affordable, better environmentally and recovers more reusable material.”
ORNL researchers developed a menu of direct recycling methods, allowing companies to choose the one best suited to the way the components will be reused. These techniques expand both “upstream” recycling from the cutting room floor and “downstream” options after the battery has reached the end of its useful life.
One new method allows the electrode layers to be peeled off intact for reuse. This can save money and materials for battery manufacturers, because about 5% of expensive cathode materials are currently wasted as scrap during initial production, Belharouak said. Plus, the components don’t have to be reformulated from scratch.
ORNL researchers also developed recycling approaches that are more helpful for spent batteries. Either of two reusable, non-toxic solvent processes can be used to dissolve the cathode and anode, returning each to its component metal alloys in the form of powders or flakes.
Existing direct recycling approaches have mostly involved shredding the electrode into small, irregular pieces — a process that creates dusty debris — followed by mechanical shaking to beat the metal electrode coating off the battery’s current collector. The ORNL process is much cleaner and minimizes impurities, Belharouak said.
Another major challenge to the adoption of lithium-ion batteries — in addition to that of recycling — is their reliance on rare metals, such as cobalt, sourced from foreign countries. But few cobalt-free alternatives have provided the same battery life and power.
ORNL researchers have patented a vehicle battery formulation that uses nickel and iron instead of cobalt without loss of battery life. Belharouak said it uses less material than other cobalt-free formulations while getting the same mileage and faster acceleration.
Lead researcher Nitin Muralidharan said, “You want something that is similar to current EV battery materials in terms of structure, energy density, electrochemical behavior and voltage range.” The ORNL battery material provides that while adding an advantage over other cobalt-free batteries: “It fits seamlessly into existing products and processes,” Muralidharan said. “The materials can be manufactured, and battery components can be assembled, using existing facilities.” ORNL engineers have already figured out how to scale up the method for industrial production.
For more information about licensing the technologies invented by ORNL battery researchers, contact ORNL’s Partnerships team at firstname.lastname@example.org, or 865.574.1051.
Under DOE’s Office of Energy Efficiency and Renewable Energy, the Vehicle Technologies Office supported the research. Inventors of the licensed technologies include Ilias Belharouak, Yaocai Bai, Rachid Essehli, Nancy Dudney, Raymond Unocic, Jianlin Li, Zhijia Du, David Wood, Ethan Self and Nitin Muralidharan. Former ORNL researchers Jagjit Nanda, Sreekanth Pannala, Chaitanya Narula, Surendra Martha, Marissa Wood, Chengyu Mao and Devendrasinh Darbar also contributed to the patented technologies.
UT-Battelle manages ORNL for the Department of Energy’s Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.