Optimized Lithium Recovery from Brines by using an Electrochemical Ion-Pumping Process Based on λ-MnO2 and Nickel Hexacyanoferrate

Currently, Li is mainly produced from Li-rich brines through the lime-soda evaporation process, which requires a long time and several purification steps, and has a severe environmental impact. Herein, ion-pumping technology based on -MnO2 as lithium-capturing electrode is presented. The method has high lithium selectivity and can increase the lithium purity from 4.1 to 96% in a single step. In addition, the time required to achieve the target lithium concentration (5000ppm) can be reduced from the 12-14months needed for the lime-soda evaporation process to less than 7.4h. The small volume of water required, the absence of any chemical reactant, the recyclability of the used electrodes, and the possibility to combine ion-pumping technology with renewable energy sources makes this process a potential ecofriendly alternative to the current lithium-recovery methods.