Efficient Direct Cathode Regeneration for Spent Lithium-Ion Batteries via Planetary Centrifugal Mixing and Eutectic Salts

Establishing a sustainable, closed-loop energy system of lithium-ion batteries (LIBs) requires the development of an efficient and scalable process for reclaiming cathode materials from end-of-life (EOL) LIBs. In this study, we introduce a novel approach for direct cathode regeneration leveraging planetary centrifugal mixing-assisted eutectic molten salt processes. Unlike conventional molten salt methods, our technique utilizes localized frictional heating induced by planetary centrifugal mixing to achieve transient eutectic melting at room temperature, enabling uniform lithium-ion transport into chemically delithiated Li1–xNi0.333Mn0.333Co0.333O2 cathode materials. This mechanochemical strategy enhances the homogeneity of the lithium distribution, shortens calcination times, and facilitates efficient structural repair of degraded cathodes. Comprehensive analyses confirmed partial relithiation and structural restoration even at the mixing stage, while subsequent short calcination and annealing fully restored lithium content, crystal lattice parameters, and electrochemical characteristics. Electrochemical evaluations revealed superior performance of the regenerated cathodes, demonstrating discharge capacities of up to 158.5 mAh/g at 0.1C with 97% capacity retention after 100 cycles at C/3. This innovative, scalable method significantly reduces energy consumption and processing time, marking an important advancement in sustainable LIB recycling.