Large-Scale Feasibility of the EnAM-Concept Demonstrated in the Pyrometallurgical Treatment of NMC Lithium-Ion Battery Black Mass and Full Cells

Abstract Pyrometallurgical recycling of spent lithium-ion batteries enables efficient recovery of cobalt, nickel and copper, while lithium predominantly reports to the slag phase. Valorizing lithium-rich slags remains a key challenge, with limited pilot-scale data available on mass flows, energy demand and emissions. This study presents pilot-scale trials in a 300 L Top Blown Rotary Converter (TBRC), treating black mass and full end-of-life NMC cells under near-industrial conditions. Continuous monitoring and centralized data acquisition enabled complete mass and energy balances, time-resolved off-gas analysis and product characterization. A novel approach—Engineering of Artificial Minerals (EnAM)—was introduced, employing controlled cooling to promote γ -LiAlO 2 formation in slags, facilitating flotation-based lithium recovery. Key results include ~99% reduction efficiency for Cu, Ni and Co, and ~45% Mn transfer to metal for black mass feed. Energy consumption averaged ~8.5 kWh/kg, with approximately 62% supplied by the burner. Black mass treatments yielded higher HF emissions than full-cell treatments, while Al foils in full cells enhanced Mn partitioning into the slag–metal system. Controlled cooling at 25 °C/h, either directly after treatment (full battery cells) or after post-remelting (black mass), is beneficial for immobilizing lithium as γ -LiAlO 2 . The EnAM from full battery cells immobilized 76% of the lithium present in the slag as γ -LiAlO 2 , compared with 44% immobilized in the EnAM from black mass. These pilot-scale trials provide a dataset to support future life-cycle assessments and demonstrate that EnAM could be a viable pathway for lithium recovery when integrated with established pyrometallurgical practices. Graphical Abstract