Phase-selective recovery and regeneration of end-of-life electric vehicle blended cathodes via selective leaching and direct recycling
Laura L. Driscoll, Abbey Jarvis, Rosie Madge, Elizabeth H. Driscoll, Jaime-Marie Price, Roberto Sommerville, Felipe Schnaider Tontini, Mounib Bahri, M. A. A. Miah, B. Layla Mehdi, Emma Kendrick, Nigel D. Browning, Phoebe K. Allan, Paul A. Anderson, Peter R. Slater
Abstract
Large-scale recycling and regeneration of lithium-ion cathode materials is hindered by the complex mixture of chemistries often present in the waste stream. We outline an efficient process for the separation and regeneration of phases within a blended cathode. We demonstrate the efficacy of this approach using cathode material from a Nissan Leaf end-of-life (40,000 miles) cell. Exploiting the different stabilities of transition metals in acidic media, we demonstrate that ascorbic acid selectively leaches low-value spinel electrode material (LiMn2O4) from mixed cathode electrode (LiMn2O4/layered Ni-rich oxide) in minutes, allowing both phases to be effectively recovered separately. This process facilitates upcycling of the Li/Mn content from the resultant leachate solution into higher-value LiNixMnyCozO2 (NMC) phases, whereas the remaining nickel-rich layered oxide can then be directly regenerated. The method has been extended to other mixtures, with preliminary results illustrating the successful selective leaching of a sodium-ion cathode from a mixture with NMC811.