Microwave-assisted process for sustainable recycling of blended cathodes from E-scooter batteries: An integrated optimization approach

This study focuses on mitigating the challenge of recycling Lithium-ion Batteries by proposing an optimized process for recovering critical metals from spent lithium-ion batteries. The study focuses on the leaching of black mass from used blended cathode material composed of lithium-manganese oxide (LiMn2O4) and lithium nickel-manganese-cobalt oxide (LiNixMnyCozO2), employing two approaches: hot plate and microwave-assisted methods. Experimental results revealed that the microwave method, using nitric acid as a leaching agent, offers several advantages over conventional techniques, such as shorter leaching times and reduced energy consumption. A comprehensive analysis of process variables was performed using Doehlert's experimental design. The initial stage involved separating the aluminum collector from the cathode material, accomplished with a NaOH solution at a concentration of 100 g/L and 1.8 mol/L over 125 min. Furthermore, the microwave-assisted leaching technique was more effective in dissolving these metals, with a complete dissolution of Li, Co, Mn, and Ni. The leached solution that was recovered was subsequently used to regenerate LiNi1/3Co1/3Mn1/3O2, which demonstrated outstanding electrochemical performances with a specific capacity of 160 mAh/g after 100 cycles at C/5 rate.