Researchers at Michigan Technological University (MTU), part of the US Department of Energy’s (DoE) ReCell team, have developed a process for separating the materials that make up the cathode, a battery’s positively charged electrode. Scientists at the Materials Engineering Research Facility, a part of DoE’s Argonne Laboratory, are now working to scale up the technology to support large scale recycling of electric vehicles.
ReCell reports that the technique is based on one used by the mining industry to separate and purify ores. It uses froth flotation to separate materials in a flotation tank based on whether they repel water and float, or absorb water and sink. Generally, cathode materials sink, which makes them difficult to separate from each other. What the researchers found was that separation can be achieved by making one of the cathode materials, lithium nickel manganese cobalt oxide (NMC111), float via the introduction of a chemical that makes the target material repel water.
Once the cathode materials were separated, the researchers determined that the process had a negligible impact on the electrochemical performance of the materials and also resulted in high purity levels (95 percent or above).
The ReCell Center is a collaboration of industry, academia and national laboratories working to advance recycling technologies along the entire battery life-cycle for current and future battery chemistries. The Center aims to grow a sustainable advanced battery recycling industry by developing economic and environmentally sound recycling process that can be adopted by industry for lithium-ion and future battery chemistries.
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