<p>In view of the difference in coordination capacity of the glycine ion (Gly⁻), a selective leaching process for treating with spent lithium-ion batteries (LIBs) in the alkaline glycinate system was proposed. The effects of retention time, leaching temperature, concentration of glycine ligand, liquid-solid ratio (L/S), pH, stirring speed, and H₂O₂ dosage on the leaching efficiency of valuable metals and the dissolution of impurities were investigated. When the spent LIBs were leached in 3 mol/L glycine aqueous solution with pH of 8, L/S of 5 mL:1 g and H₂O₂ dosage of 5 vol.% at 90 °C and stirring speed of 400 r/min for 3 h, lithium, cobalt, nickel, and manganese recoveries were 96.31%, 83.18%, 91.56%, and 31.16%, respectively, but Ca, Al, Fe, and Cu were almost insoluble. Meanwhile, the kinetic study showed that the activation energies for the leaching of Li, Co, Ni, and Mn were all in the range of 45–61 kJ/mol. The results indicate that the leaching process is all controlled by chemical reactions.</p>