Recovering Spent Li-ion Batteries as Li2CO3 and NCM (Nickel Cobalt Manganese) Carbonate Precursor by Thermal Reduction and Co-precipitation Combined Process

Addressing the escalating volume of retired lithium-ion batteries (LIBs) is crucial for protecting the environment and minimizing resource wastage. In this study, Li 2 CO 3 and NCM 111 carbonate precursor ((Ni 1/3 Co 1/3 Mn 1/3 )CO 3 ) were successfully generated from the retired ternary LIBs through a combined process of thermal reduction and carbonate precipitation. During the thermal reduction process, graphite interacted with the cathode material (LiNi 0.5 Co 0.2 Mn 0.3 O 2 ) from used LIBs, facilitating the conversion of Li from its LiO x polyhedral structure into Li 2 CO 3 . Simultaneously, the transition metals within LiNi 0.5 Co 0.2 Mn 0.3 O 2 were transformed into Ni (0) , Co (0) , and MnO. Under optimal conditions, a graphite/LiNi 0.5 Co 0.2 Mn 0.3 O 2 mass ratio of 0.15/1 was sintered at 750 °C for 120   min, resulting in the recovery of 98.7% Li as Li 2 CO 3 with a purity of 99.65% through water leaching and evaporation. After isolating Li as Li 2 CO 3 from spent NCM, the residue was dissolved and co-precipitated as NCM111 carbonate precursor ((Ni 1/3 Co 1/3 Mn 1/3 )CO 3 ) using ammonium complexing agents, with recovery ratios of 98.4%, 99.4%, and 99.7% for Ni, Co and Mn, respectively. The recovered precursors exhibited spherical morphology and rhodochrosite crystal structure. These results offer valuable insights into recycling valuable metals from used NCM batteries, thereby promoting the sustainability of the new energy industry.