A novel method for recovering valuable metals from spent lithium-ion batteries inspired by the mineral characteristics of natural spodumene

Abstract

Based on the unique crystal structure characteristics of natural spodumene (LiAlSi2O6) with six coordination of Li at the M2 position and monoclinic crystal system, an innovative approach is developed for the simultaneous recovery of Co, Ni, and Cu, while selectively enriching Li into the slag. The slag system was designed and controlled according to thermodynamic simulations and calculations to provide the theoretical basis for subsequent experiments. The effects of the ratio of Al2O3 to SiO2, temperature, and ratio of raw material to oxidizer addition on metal recovery were systematically investigated. The results showed that Li, Co, Ni, and Cu recovery efficiencies could exceed 99%, while Li was concentrated in the slag with a high grade of Li2O (6.0–9.0 wt%) under the experimental conditions, which is about 1.0–1.6 times that of the commercially available spodumene concentrate (Li2O, 5.5 wt%). By sulfation roasting-leaching of this lithium-rich slag, a leaching efficiency of Li can be achieved to 93%. This study provides valuable insights into shortening the recycling process of spent lithium-ion batteries and increasing the comprehensive utilization rate of high-value metals.