MTU Researchers Look to Make LiB Recycling More Economically Feasible
New research from Michigan Technological University (MTU) took another step toward making the battery-recycling process more cost-effective.
Lithium-Ion batteries are crucial to many applications. With the increasing demand for lithium batteries and the decreasing amount of lithium on the earth’s crust, battery recycling has come to the forefront of research.
A research team from ReCell Center, a battery recycling research and development center, found a way to overcome a challenge that was making lithium-battery recycling a non-economically feasible process.
Direct recycling is the least energy-intensive method of recycling a lithium-ion battery. Image courtesy of Argonne National Laboratory
Traditional Recycling Methods
Currently, the number of end-of-life batteries is low, but the researchers project that within a decade two million tons of end-of-life lithium-ion batteries from electric vehicles are going to be sent to retirement. Current methods of battery recycling will not be able to compensate for this amount of lithium recycling.
Current recycling methods such as hydro process recycling and pyro process recycling face two problems. The first is that the metals recovered from recycling are of low value to the manufacturers. The second problem is that these methods are highly energy-intensive.
“If the battery industry is going to buy recycled cathode material to reuse in new batteries, they are not going to sacrifice purity,” said Jessica Durham, a materials scientist at Argonne and co-author of the study.
The Direct Recycling Method
The researchers used the froth flotation process. Froth flotation is a process that separates hydrophobic materials from hydrophilic materials.
The researchers used two mixtures, lithium nickel manganese cobalt oxide (LMC111) and lithium manganese oxide (LMO). Using the froth flotation process LMC111 materials were hydrophobized where the researchers found that NMC111 floats when introduced to a chemical that repels water and LMO materials were left hydrophilic.
The results showed that the materials maintained their electrochemical properties. The froth product purity of NMC111 lied between 95% and 98%. These results ensure that if combined with a good restoration process the cathode materials recycled can be used to manufacture new lithium-ion batteries.
“That’s very important,” says Durham. “Because if the battery industry is going to buy recycled cathode material to reuse in new batteries, they are not going to sacrifice purity.”
The ReCell team completed one step toward reaching a feasible recycling process, and are willing to complete the process.
“Whatever method is used to do this recycling, the recycler has to be able to profit from it,” Durham said. “We’re putting the steps together knowing that, in the end, the total process is going to have to be profitable.”
Direct recycling and reusing battery cathode materials closes the loop. Image courtesy of Argonne National Laboratory
The research is conducted at the Materials Engineering Research, Argonne National Laboratory. It is supported by the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy, and the Vehicle Technological Office.