"Lithium Extraction from Seawater through Pulsed Electrochemical Intercalation"

Chong Liu: Yanbin Li, Dingchang Lin, Po-Chun Hsu, Bofei Liu, Gangbin Yan, Tong Wu, Yi Cui, Steven Chu; Joule, 07/01/20.

Additional Authors: Yanbin Li, Dingchang Lin, Po-Chun Hsu, Bofei Liu, Gangbin Yan, Tong Wu, Yi Cui, Steven Chu

Abstract:

It is highly attractive to develop efficient methods to directly extract Li from seawater to secure the supply of Li. However, high concentration of Na in the seawater poses a great challenge in Li extraction. Here, we developed pulsed-rest and pulse-rest-reverse pulse-rest electrochemical intercalation methods with TiO2-coated FePO4 electrodes for Li extraction. The method can lower the intercalation overpotential and successfully boost the Li selectivity. Moreover, the pulse-rest-reverse pulse-rest method can also promote electrode crystal structure stability during the co-intercalation of Li and Na and prolong the lifetime of the electrode. We demonstrated 10 cycles of successful and stable Li extraction with 1:1 of Li to Na recovery from authentic seawater, which is equivalent to the selectivity of ∼1.8 × 104. Also, with lake water of higher initial Li/Na ratio of 1.6 × 10−3, we achieved Li extraction with more than 50:1 of Li to Na recovery.