Recycling and regeneration of failed layered oxide cathode materials for lithium-ion batteries

With broad usage of lithium-ion batteries (LIBs) in electronic devices and electric vehicles (EVs), a large number of decommissioned LIBs will be generated, which cause serious environmental pollution and waste of resources. Therefore, to reduce environmental pressure and realize secondary resource utilization of valuable metals, recycling decommissioned LIBs is urgent. At present, although pyrometallurgy, hydrometallurgy, direct regeneration and other methods have been used significantly in the recovery of failed LIB cathode materials, it is still necessary to formulate the best recovery strategy to achieve higher recovery efficiencies and value-added materials from spent cathodes. Thus, in this article, the latest progress in the recycling of retired LIB layered oxide cathode materials is reviewed in detail, and the recycling process, advantages and limits of each recycling method are analyzed. In view of the recycling challenges, the future development is prospected to promote the sustainable, environmentally friendly and efficient reutilization of failed LIB cathodes and contribute to the low-carbon circular economy.