Regeneration of graphite and manganese carbonate from spent lithium-ion batteries for electric vehicles

Nowadays, recycling highly valuable elements from spent lithium-ion batteries has attracted widespread attention. In this paper, the valuable components in spent lithium manganate batteries were systematically recycled. For the mixed powder of lithium manganate and graphite, the acid leaching process was used to separate graphite and metal elements such as lithium and manganese. When the concentration of H2SO4 is 0.5 mol/L and the concentration of H2O2 is 6%, LiMn2O4 is basically completely decomposed, and the leaching rates of manganese and lithium reach 98.13% and 99.62%, respectively; meanwhile, regenerated graphite with purity of 97.62% was obtained. The particle size distribution and specific surface area of regenerated graphite meet the standard of graphite anode material for lithium-ion battery, and the electrochemical tests indicate that the regenerated graphite has high capacity and good cycling performance; the initial discharge-specific capacity and coulombic efficiency at 0.2 C are 286.9 mAh·g−1 and 71.0%, respectively. In addition, the regenerated graphite also exhibits excellent long cycle life. Furthermore, the extraction of manganese was carried out from the acid leaching solution, and the MnCO3 with purity of 98.41% were prepared. This process has great potential for industrial-scale recycling from spent lithium-ion batteries.