A Review of Direct Recycling Processes for Lithium-Ion Battery Cells

In recent years, circular economy principles have become a key paradigm in the design and evaluation of industrial processes, including recycling technologies. Direct recycling of used lithium-ion batteries is attracting particular attention, as it can significantly reduce energy consumption, reagent costs, and the carbon footprint of the entire process compared to traditional hydro- and pyrometallurgical methods. This paper provides an overview of the current state of knowledge, synthesizes contemporary methods of Li-ion battery cell recycling, and presents the most important achievements in the field of direct recycling, with particular emphasis on the regeneration and re-leaping of cathode materials, and discusses the implementation and economic premises. Key challenges and research gaps are also identified, including the need to use computational modeling (CFD/DEM, kinetic and data-driven models) to optimize the deactivation, separation, and regeneration stages. This review concludes that direct recycling has the potential to become the leading circular economy pathway for Li-ion batteries, provided that quality standardization and process modeling tools are developed in parallel.