LiFePO4-Zn battery system for electrochemical extraction of Li+ from salt lake brine with high Na+/Li+ ratio

Lithium extraction from salt lakes represents a crucial approach to developing lithium resources and plays a vital role in advancing the global energy transition. China possesses abundant lithium resources in its salt lakes. However, the high sodium content present in salt lake brines presents a significant challenge to efficient lithium extraction. This study investigates the capability of the LiFePO 4 -Zn battery system for extracting lithium from salt lake brine with a high Na + /Li + ratio. The system demonstrates a significant rejection effect on Na + and exceptional selectivity for Li + , even in high-concentration sodium ion aqueous solutions. In a chloride aqueous solution containing 0.25 g/L of Li⁺ and 100 g/L of Na⁺, the sodium-to-lithium mass ratio decreased from 400 to 13.52 after three cycles, indicating that the extraction efficiency of Li⁺ achieved reached 90.28 %.