A Novel Method for the Recovery of Li from Spent Lithium-Ion Batteries Using Reduction Roasting–Countercurrent Leaching.

A novel method for the recovery of Li from cathode material of waste ternary lithium-ion batteries is proposed, wherein water-based leaching of the reduction roasting product was conducted. First, the effects of leaching temperature, leaching time, liquid–solid ratio, and CO₂ aeration rate on the recovery of Li were investigated, demonstrating that the leaching rate of Li can reach 79.95% under optimal conditions, i.e., a CO₂ aeration rate of 200 mL/min, leaching time of 1.5 h, and liquid–solid ratio of 15:1, at 15°C. The leaching time and CO₂ aeration rate had little impact, while the liquid–solid ratio and temperature were found to significantly affect the leaching rate of Li. Then, counter-current leaching experiments were carried out, and the total leaching rate of Li exceeded 98% after four stages with a liquid-to-solid ratio of 15:1. Battery-grade purity of the lithium carbonate product was obtained by evaporative crystallization. [ABSTRACT FROM AUTHOR]