Selective Lithium Adsorption of Silicon Oxide Coated Lithium Aluminum Layered Double Hydroxide Nanocrystals and Their Regeneration

Abstract

Silicon oxide-coated lithium aluminum layered double hydroxide (Li x Al 2 -LDH@SiO 2 ) nanocrystals (NCs) are investigated to selectively separate lithium cations in aqueous lithium resources. We directly synthesized Li x Al 2 -LDH NC arrays by oxidation of aluminum foil substrate under a urea and lithium solution. Various lithium salts, including Cl À , CO 3 2À , NO 3 À , and SO 4 2À , were applied in aqueous solution to confirm the anion effect on the captured and released lithium quantity of the Li x Al 2 -LDH NCs. In a 5% solution of sulfate ions mix with lithium chloride, the Li x Al 2 -LDH NCs separated a larger quantity of lithium than in other anion conditions. To enhance regeneration stability and lithium selectivity, thin layers of SiO 2 were coated onto the Li x Al 2 -LDH nanostructure arrays for inhibition of nanostructure destruction after desorption of lithium cations in hot water. The Li x Al 2 -LDH@SiO 2 nanostructures showed enhanced properties for lithium adsorption, including increase of stable regeneration cycles from three to five cycles, and they showed high lithium selectivity in the Mg 2 + , Na + , and K + cation mixed aqueous resource. Our nanostructured LDH lithium adsorbents would provide a facile and efficient application for cost-efficient and large-scale lithium production.

Cross-Linked Phosphorylated Cellulose as a Potential Sorbent for Lithium Extraction from Water: Dynamic Column Studies and Modeling

“…Adsorption is the most promising strategy for recovering Li from aqueous resources because it is more climate-friendly and more effective in an industrial application . Although there are many studies reported in the literature regarding metal ion extraction based on different functionalized composite materials, − aluminum hydroxides (AlOH), , aluminum oxides (AlO x ), manganese oxides (MnO x ), − and titanium oxides (TiO x ) ,− have been known to be the most selective lithium adsorbents until now. They are classified as inorganic crystalline solids either being studied for direct lithium extraction from brines or employed as cathode materials in lithium-ion batteries.…”