Lithium recovery from mixed spent LFP-NMC batteries through atmospheric water leaching
Indra Perdana, Doni Riski Aprilianto, Farika Asna Fadillah, Riskal Fadli, Himawan Tri Bayu Murti Petrus, Widi Astuti, Muhammad Akhsin Muflikhun, Hanida Nilasary, Haryo Satriya Oktaviano, Ferry Fathoni, Edo Raihan, Soraya Ulfa Muzayanha
Abstract
Selective lithium recovery from a mixture of LFP-NMC spent lithium batteries presents significant challenges due to differing structures and elemental compositions of the batteries. These differences necessitate a distinct recycling pathway for each, complicating the process for the mixture. This study explored a carbothermal reduction approach combined with water leaching under atmospheric conditions to achieve a selective lithium recovery. For individual NMC black mass, at the optimal carbothermal conditions (950 °C, 15 °C/min, 2 h), lithium recovery of 95.7 ± 0.31% with 100% selectivity could be achieved. However, when the black mass was mixed with that of LFP in a 50:50 ratio, the recovery dropped to 9.78 ± 0.44%. Solid-state reactions during carbothermal process resulted in the formation of highly insoluble Li 3 PO 4 , and Fe-Ni-Co/Ni-Co alloys, which hinder lithium dissolution. To address these challenges, Na 2 CO 3 was introduced as an additive to suppress Li 3 PO 4 . The addition of Na 2 CO 3 to the 50:50 ratio of LFP-NMC black mass, increased lithium recovery to 59.47% with 100% selectivity. This enhancement was due to the stabilization of lithium as Li 2 CO 3 , a water-soluble compound. The results demonstrated that addition of Na 2 CO 3 is a promising strategy for improving lithium recovery from mixed LFP-NMC batteries, providing a potential pathway for a more efficient recycling process.