Maximizing resource recovery: A green and economic strategy for lithium extraction from spent ternary batteries

Spent ternary lithium-ion batteries contain abundant lithium resource, and their proper disposal is conducive to environmental protection and the comprehensive utilization of resources. Separating valuable metals in the ternary leaching solution is the key to ensuring resource recovery. However, the traditional post-lithium extraction strategies, which heavily rely on ion exchange to remove transition metal ions in the leachate, encounter challenges in achieving satisfactory lithium yields and purities. Based on this, this paper proposed a new strategy to prioritize lithium extraction from ternary leachate using "(+) LiFePO4/FePO4 (-)" lithium extraction system. The preferential recovery of lithium can be realized by controlling the potential over 0.1 V versus Standard Hydrogen Electrode (SHE) without introducing any impurity ions. The lithium recovery rate reaches 98.91%, while the rejection rate of transition ions exceeds 99%, and the separation coefficients of lithium to transition metal ions can reach 126. Notably, the resulting lithium-rich liquid can directly prepare lithium carbonate with a purity of 99.36%. It provides a green and efficient strategy for the preferential recovery of lithium from the spent ternary leachate.

Selective lithium extraction from spent lithium-ion batteries through polyvinyl chloride thermal decomposition-based gas-solid reaction

The recovery of valuable metals from waste battery materials and the thermal decomposition of PVC both require significant energy and material consumption. In this study, we propose an innovative strategy that integrates the lithium extraction process from spent LiNi0.85Co0.15Al0.05O2 (S-NCA) with PVC pyrolysis, resulting in a substantial reduction in energy consumption and chemical additive. Various characterization techniques, including SEM, TEM, XRD, and XPS, are employed to investigate the mechanism of gas-solid lithium extraction and provide valuable insights into the migration pathway of lithium from S-NCA to soluble LiCl. The optimal conditions for the process were determined as follows: a temperature of 600 °C, S-NCA/PVC mass ratio of 1:4, and a baking time of 2 h, achieving a lithium extraction efficiency of 94.37 %. The research provides valuable insights for the valorization of PVC thermal decomposition and lithium extraction from NCA, presenting a novel approach for future applications.

Electrochemical selective lithium extraction and regeneration of spent lithium iron phosphate

In this paper, a green, efficient and low-cost process for the selective recovery of lithium from spent LiFePO4 by anodic electrolysis is proposed. The leaching rates of Li, Fe and P under different conditions were explored and the optimal conditions are obtained. In the optimal conditions, Li, Fe and P leaching rates were 96.31%, 0.06% and 0.62% respectively. The Li/Fe selectivity was over 99.9%. The product obtained is isostructural FePO4 and retains the original particle morphology. The FePO4 obtained can be synthesised into LiFePO4/C by direct regeneration process or impurity removal regeneration process. The material synthesized by the latter process has a better electrochemical performance, with a discharge specific capacity of 144.5 mAh/g at 1.0C and a capacity retention of 92.0% over 500cycles. The superior performance can be attributed to an impurity removal process that reduced agglomeration and improved particle morphology.