• Selective leaching of Li, Co, Ni, and Mn from spent LIBs is achieved in an alkaline glycinate system, with recoveries of 96.31%, 83.18%, 91.56%, and 31.16%, respectively, while Ca, Al, Fe, and Cu remain nearly insoluble.
• The process uses environmentally friendly glycine as a complexing agent, enabling high metal recovery without strong acids and reducing toxic waste.
• Kinetic analysis reveals activation energies of 45–61 kJ/mol for Li, Co, Ni, and Mn, indicating that leaching is controlled by chemical reactions, not diffusion.
• This selective leaching approach simplifies downstream metal separation and enhances the sustainability of spent lithium-ion battery recycling.
• Optimal conditions include 3 mol/L glycine at pH 8, L/S ratio 5 mL/g, 5 vol.% H2O2, 90 °C, and 400 r/min for 3 h.