Dual-Channel-Ion Conductor Membrane for Low-Energy Lithium Extraction

Abstract

The development of energy-efficient and environmentally friendly lithium extraction techniques is essential to meet the growing global demand for lithium-ion batteries. In this work, a dual-channel ion conductor membrane was designed for a concentration-driven lithium-selective ion diffusion process. The membrane was based on a porous lithium-ion conductor, and its pores were modified with an anion-exchange polymer. Thus, the sintered lithium-ion conductors provided highly selective cation transport channels, and the functionalized nanopores with positive charges enabled the complementary permeation of anions to balance the transmembrane charges. As a result, the dual-channel membrane realized an ultrahigh Li + /Na + selectivity of ∼1389 with a competitive Li + flux of 21.6 mmol•m −2 •h −1 in a diffusion process of the LiCl/NaCl binary solution, which was capable of further maintaining the high selectivity over 7 days of testing. Therefore, this work demonstrates the great potential of the dual-channel membrane design for high-performing lithium extraction from aqueous resources with low energy consumption and minimal environmental impact.

Membrane Design Principles for Ion-Selective Electrodialysis: An Analysis for Li/Mg Separation

“…However, it is unclear whether such PA-CEMs can readily be made following the protocols for fabricating PA-based NFMs reported in the literature since the properties of the support layer (e.g., CEM vs polysulfone support) may substantially change the interfacial polymerization process and thus the final PA layer properties. We also note that membranes with ion-specific channels or other separation mechanisms may achieve better separation performance than the composite membranes considered here and is thus worthy of future investigation and comparison. ,, Furthermore, energy consumption and cost analysis are also necessary in future analysis for a comprehensive performance comparison, especially considering that one major benefit to substitute monovalent selective CEMs by NFMs is to reduce the membrane cost.…”

“…We also note that membranes with ion-specific channels or other separation mechanisms may achieve better separation performance than the composite membranes considered here and is thus worthy of future investigation and comparison. 14 , 76 , 77 Furthermore, energy consumption and cost analysis are also necessary in future analysis for a comprehensive performance comparison, especially considering that one major benefit to substitute monovalent selective CEMs by NFMs is to reduce the membrane cost.…”

Lithium-Ion-Sieve-Embedded Hybrid Membranes for Anion-Exchange- and Cation-Concentration-Driven Li/Mg Separation

“…At present, the technologies for extracting lithium from salt-lake brine mainly include precipitation, solvent extraction, adsorption, and membrane separation. − Among them, membrane-based separation technologies, such as nanofiltration, − electrodialysis, diffusion dialysis, and liquid membrane extraction, ,, are considered to be a clean strategy because of their high efficiency, low energy input, and low pollution. , The concentration-driven diffusion dialysis is independent from the pressure and electrical potentials, making it a cost- and energy-efficient process for ion separation. , …”