EARTH

[2901-14-09] Selectively leaching of valuable matals from spent Lithium-ion battery by ammonium sulfate

○Nannan Liu¹, Yongming Chen¹, Cong Chang¹, Lulu Guo¹ (1. Central South University)

Chairman：Kyoungkeun Yoo （Korea Maritime and Ocean University）, Wei Sheng Chen (National Cheng Kung University)

Keywords:Spent Li-ion battery, Cathode active material, Recycling, Ammonium leaching

In this study, the leaching behavior of the cathode active materials separated from various commercial LIBs in mobile phone was investigated using ammonium leaching agent based on ammonia sulfate and ammonium sulfite.The process parameters foe the leaching of the cathode active powder were optimized by varying the leaching temperature, addition of reductant, concentration of leachant, S:L ratio and time. Results indicate that the optimized leaching rate of Ni, Co, Li and Mn is 96.49%, 88.42%,97.41% and 4.27% respectively when the material was leached in 3M (NH₄)₂SO₄, 136g (NH₄)₂SO₃(1.5 times of Co molar mass in the input cathode materials) at 200 degree Celsius, and S:L ratio of 100 g/L for 180 min. It was found that Mn could be reduced into the solution from Mn⁴⁺ to Mn²⁺ with appropriate addition of reductant. And, the Mn²⁺ in the solution would be precipitated out in the forms of (NH₄)₂Mn(SO₃)₂·H₂O and (NH₄)Mn(SO₄)₂·6H₂O with further increasing the addition of reductant. As a result, this ammonium leaching process could provide an alternative way for the selectively leaching of value metals from spent Lithium-ion battery in industry.