Abstract:

The unavoidable need for growth of transport electrification, electric cars, and renewable energy systems has driven the demand for lithium-ion batteries (LIBs), resulting in a surge of end-of-life (EOL) batteries, creating both challenges and opportunities for recycling. Recycling efforts have traditionally focused on recovering high-value metals (such as lithium, cobalt, and nickel); however, graphite used as the primary anode material remains largely overlooked despite its significant contribution to battery mass and its strategic importance in the supply chain. This study explores the economic feasibility of recycling graphite from EOL LIBs by comparing its recovery costs with those of natural and synthetic graphite sources. Graphite, often treated as waste or incinerated, represents a lower value opportunity for battery recycling efficiency and circular economic strategies. To address this gap, we evaluate the cost efficiency of graphite recovery from Black Mass; Black mass is produced and processed by discharging and dismantling used batteries, followed by mechanical treatment such as shredding, grinding, and magnetic or density separation to remove plastics and casings from the rest of the battery. The proposed process starts with heat treatment, followed by flotation, acid washing, solid/liquid separation, drying, second heat treatment (regeneration), lump breaking, agglomeration and carbon coating, third heat treatment (carbonization). Beyond direct economics, graphite recovery offers environmental and strategic benefits, including reduced dependence on imported natural graphite and a lower carbon footprint. These advantages may strengthen long‑term feasibility as sustainability policies evolve. Despite all technical and environmental advantages, recycled graphite must still meet electric vehicle-grade performance requirements, which can be challenging due to mixed feed compositions. Since commercial LIBs rely on optimized blends of natural and synthetic graphite, quality inconsistencies are common in recycled material. Density-based separation and other advanced methods can help improve product performance. Logistical design also affects feasibility. As graphite constitutes approximately 30–40% of black mass by weight, integrating graphite separation at the spoke facilities can reduce transportation volumes and associated emissions, particularly when graphite processing occurs at a different site. This approach improves both cost efficiency and sustainability.

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Thomas Bibienne