Recovery of Lithium and Heavy Non-Ferrous Metals from Spent Lithium-Ion Batteries

We describe an economical and environmentally advantageous, mechanical/chemical procedure for recycling spent lithium-ion batteries removed from a portable computer. The battery cathode comprises complex Li-based oxides: lithium-cobalt-oxide, lithium-nickel-cobalt-aluminum oxide and/or lithium-nickel-cobalt oxide, while the anode is constructed from a graphite-coated copper foil. Other carbon-containing materials should also be present. The electrolyte, the composition of which is not made available by the manufacturer, is probably a Li salt in organic solvent. Following hand removal of the non-metallic container, the battery elements undergo crushing/milling; no other component separation procedure is performed or required. Sixty minute dilute natural gas (4 vol.% in N2) sintering under reducing conditions (673-1123 K), followed by ice-water leaching, is used to efficiently separate Li from the heavy metals in the form of lithium carbonate at high yield and purity; 0.5 h smelting (1773 K) of the remaining metal clinker in air in a closed ceramic crucible, with sodium tetraborate as flux, allows recovery of the heavy, non-ferrous metals (Ni, Co, Cu and their alloys) as mm-size ingots (39% Co, 32.2% Ni, 26.3% Cu). Iron compounds, remanent Li, Al and unburnt graphite are removed as slag. Neither corrosive acids nor costly reagents are required, and hazardous liquid waste is not generated.