Conventional lithium extraction methods exhibit limited efficiency in strongly acidic solutions. This study developed a brand-new and universal lithium recovery strategy from strongly acidic systems using Li+ migration between directionally formed solid phase of lithium-aluminum layered double hydroxides (Li/Al-LDHs) and alternate aqueous solutions. Li+ ions in strongly acidic solutions with massive coexisting cations (Na+, K+, Fe2+, Ca2+, Mg2+, Al3+, etc.) were inductively converted into the solid precipitate through a precise crystal phase regulation. A non-equilibrium thermodynamic model was developed and revealed that the lithium deintercalation flux exhibited a linear dependence on the chemical potential gradient, systematically elucidating the critical parameters governing extraction efficiency. Subsequently, lithium extraction from Li+-enriched solid could be accomplished easily using neutral aqueous solutions with a complete delithiation, and the overall lithium recovery from acidic systems exceeded 96% with the residual solid recycling process and waste-free disposal. Furthermore, the lithium extraction strategy was proven applicable in authentic multi-component acidic solutions with efficient lithium recovery and low costs. This work is expected to significantly promote the development of universal extreme system lithium separation technology.
Guo et al. (Thu,) studied this question.