A microwave-enhanced method able to substitute traditional pyrometallurgy for the future of metals supply from spent lithium-ion batteries

This work presents a new and promising method to recover Li, Co, Mn, and Ni from spent LIBs, based on a hybrid heating mechanism, obtained by using microwave radiation. Due to the presence of graphite, the heating is induced by the interfacial polarization of carbon atoms. The hybrid heating is based on the synergistic combination of an external susceptor with a graphite crucible. The system allows reaching carbothermic reduction conditions of black mass originating from spent LIBs, with a treatment of only a few minutes considering an electromagnetic radiation power ⋜1000 W, without any other additives. This process reduces the required associated energy by more than 2 orders of magnitude in comparison to conventional thermal treatments. The thermal process is followed by leaching in water and l-malic acid, obtaining a recovery process resulting to be competitive with metals extraction from respective ores.