New technology can effectively recover cobalt and nickel -Lithium - Ion Battery Equipment
A new study led by Xiao Su, a professor of chemistry and biomolecular engineering at the University of Illinois at Urbana Champaign, uses selective electrodeposition to recover valuable metals from commercially available lithium nickel manganese cobalt oxide (or NMC) battery electrodes. The method was published in the journal of Nature Communication, and the final products of cobalt and nickel with purity of 96.4% and 94.1% were produced from waste NMC electrode waste respectively.(Lithium - Ion Battery Equipment)
Su said that cobalt and nickel have similar electrochemical characteristics - or standard reduction potential - which makes it difficult for chemists to recover the pure form of each metal from the battery electrode.
"There are many ways to recover cobalt and nickel from battery electrodes, but they all have disadvantages," Su said. "Most require energy intensive high-temperature processes or strong solvents, which pose treatment challenges. The industry needs methods that do not cause additional problems, such as high energy consumption or toxic waste."
The unique feature of this study is that the team developed an adjustable liquid electrolyte and polymer coating on the electrode.
In the laboratory, the researchers combined the electrolyte polymer method with the disassembly, leaching and liquefaction modules of fully discharged NMC battery electrodes. By adjusting the salt concentration of the electrolyte and the thickness of the polymer coating, the researchers noticed that different cobalt and nickel deposits were accumulated on the electrode surface area through continuous electrodeposition. At the end of the process, the electrode has collected high-purity cobalt and nickel coatings.
According to the research report, the economic analysis of the new method shows that it is competitive with the current lithium battery recycling method once the material income, material cost and energy consumption are comprehensively considered.
"Further engineering optimization of the process is required in the future, but the first proof of concept study confirmed that the electrochemical recovery of cobalt and nickel at low temperature is possible," Su said. "We are very excited because this study shows a good example of sustainable power driven separation being used to recycle electrochemical batteries."
Sue also belongs to the Beckman Institute for Advanced Science and Technology and is a professor of civil and environmental engineering in Illinois. This work was led by Kwiyong Kim, a postdoctoral research assistant in Illinois, and also contributed by graduate students Darien Raymond and Riccardo Candeago.