Comprehensive recovery of mixed spent of LiNixCoyMn(1−x−y)O2 and LiFePO4

Lithium-ion batteries are currently being scrapped in large quantities, and there are almost no reports of mixed waste disposal. This paper describes research on a comprehensive recovery process for the mixed waste of LiNixCoyMn(1−x−y)O2 and LiFePO4. The interaction of LiFePO4 and LiNixCoyMn(1−x−y)O2 is utilized to achieve selective leaching through a low H2SO4-low H2O2 system, removal of P and Fe by Fe2(SO4)3-NaOH, preparation of Ni–Co–Mn hydroxide by addition of NaOH, preparation of Li3PO4 using Na3PO4, and separation of Fe and P by acid. The research shows that when 5.23 ml/g 1 M H2SO4 and 0.308 g/g 30% H2O2 were added at 90 °C for 5 h, the leaching ratios of Li, Ni, Mn, and Co achieved were 99.589%, 98.524%, 97.079%, and 96.257%, respectively. At 90 °C and a pH 12 for 2 h, the precipitation ratios of Ni, Co, and Mn were 99.79%, 99.89%, and 99.89%, respectively. A total of 55.12 g/l of Na3PO4 was added to the solution to effect settling of Li, and a sedimentation rate of 98.46% was achieved. The leaching residue was dissolved in 3 M HCl of 6.62 ml/g, and the achieved leaching ratio of the FePO4 was more than 95%.