A fresh recycling technique tested at the U.S. Department of Energy’s Argonne National Laboratory shows how molten salts could play a decisive role in recovering valuable metals from end‑of‑life lithium‑ion batteries.
The approach focuses on extracting transition metals such as cobalt, nickel and manganese from used cathodes, helping to create a more cost‑effective and secure supply of these critical materials.
The method is a type of pyro-processing, using electricity to separate and recover metals at moderate temperatures. Researchers worked with two lithium hydroxide‑based salt mixtures that melt at lower temperatures than many industrial molten salts and cope far better with moisture — a practical advantage when dealing with real‑world battery waste.
In the first technique, a blend of lithium hydroxide and potassium hydroxide was heated to around 280°C, a temperature comparable to a domestic oven. Electricity dissolved the cathode metals into the molten salt, and electrolysis was then used to “plate” the metals onto an electrode. Crucially, the process still worked even when the salt contained moisture.
The second technique used a lithium hydroxide–lithium chloride mixture to remove lithium and oxygen from the cathode. This transformed the material into metal‑like clumps, which could then be recovered. Lithium itself was also extracted as metal through electrolysis.
“By using molten salts, we’ve developed a method that is not only efficient but also adaptable to the challenges of recycling lithium-ion batteries,” said Timothy Lichtenstein, researcher in Argonne’s Chemical and Fuel Cycle Technologies Division. Stephanie Dulovic, also of the research team, added, “This technology has the potential to transform how we recycle lithium-ion batteries.”
The team now aims to scale up to 100‑gram batches to understand how the process could fit into full industrial recycling flowsheets.
Image : Pyroprocessing lab. Credit: Argonne National Laboratory.
