Precipitation of Lithium Phosphate from Cathode Materials of Spent Lithium-Ion Battery by Hydrometallurgy Process

Abstract

Spent lithium-ion batteries (LIBs) have significantly increased due to the high consumption of LIBs for automobile applications; therefore, the recovery of valuable materials to use as the second resource can bring economic benefits and reduce an environmental impact. This study investigated the production of lithium phosphate (Li3PO4), which can be used as a starting material for the synthesis of LIBs, from spent LiNixMnyCozO2 (NMC) cathodes. The experimental procedure started with discharging, dismantling the battery, and removing the aluminum foil, followed by the leaching of cathode material before precipitating the lithium phosphate from the solution. In the leaching stage, the parameters to optimize the process were studied. The results showed that the lithium leaching efficiency could be achieved at 96.10% using 2 M H2SO4, 8 vol.% H2O2, 40 g/L pulp density, and 4 hrs at 70°C. The final precipitate product of 98.98% purity of Li3PO4 was recovered from the solution using Na2HPO4 under the experimental condition.