Electrochemical lithium extraction with continuous flow electrodes

Electrochemical lithium extraction presents the advantages of superior ion selectivity and environmental friendliness. However, it faces challenges of intermittent operation, limited areal capacity and constrained mass transfer with conventional solid electrodes. In this work, we propose a continuous electrochemical lithium extraction system by using flow electrodes. Due to the inherent fluidic characteristics, the flow electrodes facilitate efficient mass transfer, thereby manifesting boosted kinetics in the insertion and extraction of lithium ions. Compared with solid electrodes, flow electrodes exhibit a substantial augmentation in lithium extraction capacity, demonstrating a nearly sixfold increase in simulated Atacama brine and a nineteen-fold in diluted Atacama saline under equivalent current density. Furthermore, we achieve a lithium production rate of 1 mol m−2 h−1 with a purity level of 0.97 at a high current density of 4 mA cm−2. These results exemplify the capability of flow electrodes for industrial-scale lithium extraction, particularly emphasizing their suitability for large-scale and high-speed production.