A Green Process for Effective Direct Recycling and Reuse of Graphite from End-of-Life Li-Ion Batteries Black Mass.

The demand for lithium-ion batteries (LIBs) is posing challenges in the management of end-of-life (EoL) systems and supply of critical raw materials. Such challenges can be addressed by recycling EoL LIBs through sustainable processes, involving metallurgy to recover higher-value metals like Co, Ni, and Li. Pretreatment strategies allowing to reclaim other valuable materials-such as graphite, binders, and electrolytes-are also crucial to enhance the overall recycling efficiency. Despite the strategic relevance of graphite in the battery supply chain, its recovery and reuse remain poorly explored. Herein, a sustainable closed-loop approach for the reclamation and reuse of graphite from EoL LIBs black mass is proposed, exploiting a low-impact froth flotation based on green chemicals. The recovered graphite is purified through a mild chemical leaching by natural organic acids and thermally treated to restore its microstructure from damages induced by the aging phenomenon. The regenerated material is characterized by multi-sample technique approach, demonstrating high separation efficiency (>96% yield) and purity (>99.6%). The direct recycling process is validated by reusing the reclaimed graphite as secondary anode active material in new cells, showing functional performance comparable to those of the commercially available material.