Technical, economic and environmental analysis of production scraps direct recycling from lithium-ion battery manufacturing

To address the well-known limitations of current recycling methods, particularly the challenges associated with heterogeneous and degraded end-of-life (EoL) lithium-ion batteries (LIBs), including complex disassembly, electrolyte removal, and material cross-contamination, this study proposes a practical and efficient alternative based on direct recycling of production scraps. In this study a direct recycling process, which recovers active materials without altering their crystal structure, consisting in thermal treatment followed by mechanical detachment through ball milling, was applied to production scraps of lithium iron phosphate (LFP) and lithium nickel manganese cobalt oxide (NMC) cathodes. Different temperatures (200-300-400-600 °C) and air or nitrogen were explored. Experiments showed that partial melting of PVDF binder at 200 °C was sufficient to enable effective material recovery, particularly for LFP, without inducing degradation. The highest recovery yields were recorded at 400 °C in air for LFP (98 ± 7 % Fe and 99 ± 11 % Li) and at 600 °C in air for NMC (99 ± 19 % Co, 99 ± 12 % Li, 99 ± 17 % Mn and 99 ± 5 % Ni). Thermal treatment at 300 °C led to PVDF melting without degradation which increased the concentration of Al impurities in both LFP and NMC materials, likely due to the binder's molten state enhancing adhesion to the Al foil prior to its complete thermal decomposition. The economic viability of the process was confirmed by recovery costs (0.71 €/kg LFP and 1.17 €/kg NMC) lower than current virgin material prices. Greenhouse gas (GHG) emissions equal to 1.18–2.56 kg CO 2 /kg for LFP and 1.94–6.98 kg CO 2 /kg for NMC were calculated, with the most favourable trade-offs achieved at moderate temperatures in air. Due to low energy demand and easy scalability, the proposed direct recycling process holds potential for on-site recycling of scrap cathodes, particularly in regions -such as the European Union, where critical raw materials supply security and waste reduction are significant issues. • LFP recovery was more efficient and less dependent on process' temperature than NMC. • Optimal LFP direct recycling corresponds to 400 °C, 0.71 €/kg and 1.18 kg CO 2 eq/kg. • Optimal NMC direct recycling corresponds to 600 °C, 1.17 €/kg and 1.94 kg CO 2 eq/kg. • Direct recycling scrap cathodes has lower cost and CO 2 eq emissions than end-of-life.