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

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 LiFePO 4 (S-LiFePO 4 ) in the field of lithium extraction from salt lakes was proposed using spent LiFePO 4 (S-LiFePO 4 ) as raw material. The anode, made from spent LiFePO 4 , is prepared via a sintering process, while FePO 4 , obtained through chemical oxidation, is used as the cathode. Compared with commercial LiFePO 4 , this system not only reduces the cost but also greatly shortens the preparation time of FePO 4 (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.