Electrochemical ion-pumping-assisted transfer system featuring a heterogeneous membrane for lithium recovery

Abstract

Enormous demand and limited resources enable Li-ions extraction as emerging research. Herein, we demonstrate how coupled voltage facilitates lithium-selective extraction across a heterogeneous membrane consisting of a glass-type ceramic electrolyte membrane and a stable conductive composite layer. A cell voltage that directs the one-way selective permeation of Li ions is coupled with a pulse voltage that is applied to the conductive layer to accelerate the transmembrane transport of Li ions. This leads to a high Li-ion flux of 124 mmol m−2h−1, which is enhanced to 238% of the flux of no ion-pumping-assisted process. The proposed electrochemical ion-pumping-assisted transfer system (EIPATS) exhibits an excellent ability to extract Li ions from a mixed electrolyte solution, achieving Li+/Na+, Li+/K+, and Li+/Mg2+ selectivity ratios of 242, 870, and 5032, respectively. The proposed EIPATS featuring a heterogeneous membrane anticipates wide potentials in sustainable resource recovery.