Cost-effective and efficient preparation of FePO₄ electrodes from spent LiFePO₄ batteries for enhanced lithium extraction from salt lakes

Abstract

Cost-effective and efficient lithium extraction technology is vital to foster the growth of lithium industry. This paper proposed a novel approach for the high value utilization of spent LiFePO₄ (S-LiFePO₄) in the field of lithium extraction from salt lakes was proposed using spent LiFePO₄ (S-LiFePO₄) as raw material. The anode, made from spent LiFePO₄, is prepared via a sintering process, while FePO₄, obtained through chemical oxidation, is used as the cathode. Compared with commercial LiFePO₄, this system not only reduces the cost but also greatly shortens the preparation time of FePO₄ (only about 10min is required). And the electrochemical extraction system had a favorable lithium extraction capacity (29.25 mg/g) from actual brine, reducing the Mg/Li ratio from 61.4 to 0.8. This study not only achieved the low-cost preparation of electrode materials and facilitated the large-scale implementation of this process, but also proposed a high-value comprehensive utilization strategy for lithium-ion batteries recycling.