ALBERT

Description: In order to meet the global demand for lithium-ion batteries, salt lakes have been targeted as a source of lithium. However, extracting lithium from brine that contains a high Mg/Li ratio is a challenge due to the similar chemical properties of Mg 2+ and Li + . In article number 1700079 by Zhongwei Zhao and co-workers, a novel electrochemical cell is used to extract lithium from brine with high selectivity: LiFePO 4 (anode) | NaCl solution | anion exchange membrane | brine |FePO 4 (cathode). The system demonstrates good cycling performance, effective lithium enrichment, low cost, and use of environmentally friendly materials, making it a practical means to address the issue of lithium extraction.

Description: Lithium extraction from high Mg/Li ratio brine is a key technical problem in the world. Based on the principle of rocking-chair lithium-ion batteries, cathode material LiFePO 4 is applied to extract lithium from brine, and a novel lithium-ion battery system of LiFePO 4 | NaCl solution | anion-exchange membrane | brine | FePO 4 is constructed. In this method, Li + is selectively absorbed from the brine by FePO 4 (Li + + e + FePO 4 = LiFePO 4 ); meanwhile, Li + is desorbed from LiFePO 4 (LiFePO 4 − e = Li + + FePO 4 ) and enriched efficiently. To treat a raw brine solution, the Mg/Li ratio decreases from the initial 134.4 in the brine to 1.2 in the obtained anolyte and 83% lithium is extracted. For the treatment of an old brine solution, the Mg/Li ratio decreases from the initial 48.4 in the brine to 0.5 and the concentration of lithium in the anolyte is accumulated about six times (from the initial 0.51 g L −1 in the brine to 3.2 g L −1 in the anolyte), with the absorption capacity of about 25 mg (Li) g (LiFePO 4 ) −1 . Additionally, it displays a great perspective on the application in light of its high selectively, good cycling performance, effective lithium enrichment, environmental friendliness, low cost, and avoidance of poisonous organic reagents and harmful acid or oxidant. Lithium extraction from high Mg/Li ratio brine is a global technical problem. In this study, cathode material LiFePO 4 is applied to extract lithium from the brine via a novel electrochemical system of LiFePO 4 | NaCl solution | anion-exchange membrane | brine |FePO 4 . It displays a great perspective on the application in light of its high selectively, good cycling performance, effective lithium enrichment, and low cost.