Enhanced lithium separation with Li1.3Al0.3Ti1.7(PO4)3 lithium superionic conductor and aided charge balance

Abstract

Traditional technologies of lithium extraction from salt lakes suffer the low efficiency of Li⁺/Mg²⁺ separation and high energy consumption. We introduce a novel electrodialysis process that leverages Li_1.3Al_0.3Ti_1.7(PO₄)₃ (LATP, one of lithium superionic conductors) and incorporates an aided charge balance (ACB) system, all under low voltage and ultra-low current conditions. The remarkable ion selectivity of LATP, coupled with the enhanced recovery ratio facilitated by ACB, collectively empower this technology to achieve extremely high separation efficiency and remarkably low energy consumption. In a simulated pristine brine, the average Li/Mg separation coefficient reached 5924, accompanied by an exceptionally low energy consumption of only 0.80 kWh·kg⁻¹_Li. Furthermore, this technique enabled the production of battery-grade Li₂CO₃ with an outstanding purity of 99.93 %, achieved through a streamlined process comprising only two stages.