Pre-treatment Strategies for Efficient Pyrometallurgical Recycling of Lithium-Ion Batteries within the InduRed Reactor

Abstract Economic and ecological recycling of lithium-ion batteries (LIBs) is vital due to the limitations of current technologies, such as lithium-slagging in pyrometallurgy or the production of huge amounts of wastewater in hydrometallurgy. The InduRed reactor offers a potential solution capable of processing diverse input streams to produce lithium and phosphorus in the gas phase and an alloy mostly free of impurities, ideal for downstream hydrometallurgical treatment. However, achieving desired product qualities requires critical evaluation of pre-treatment steps. This study reviews existing and emerging pre-treatment technologies for LIB recycling that meet the requirements of the InduRed reactor. The discharging process, possibly through ohmic methods, moves lithium into the cathode and ensures safety during manual dismantling, acting as the primary step, followed by binder decomposition through thermal treatment at 500 to 600 °C. This optimizes material separation for mechanical comminution, sieving and other processes, which effectively yields a fine black mass powder with minimal contamination of aluminium (Al) and copper (Cu) foils. Finally, flotation adjusts the carbon content of the black mass, directly influencing its kinetic and thermodynamic behaviour in the reactor. Additionally, it was observed that for an open-loop recycling approach, phosphorus (P) and Cu should be separated as much as possible, as both elements negatively affect steel qualities.