Phase Chemistry for Hydration Sensitive (De)intercalation of Lithium Aluminum Layered Double Hydroxide Chlorides.

Content Provider	Europe PMC
Author	Li, Dongdong Zhang, Ning Gao, Dandan Zhuang, Ziyu Zeng, Dewen
Copyright Year	2023
Description	Lithium aluminum layered double hydroxide chlorides (LADH-Cl) have been widely used for lithium extraction from brine. Elevation of the performances of LADH-Cl sorbents urgently requires knowledge of the composition–structure–property relationship of LADH-Cl in lithium extraction applications, but these are still unclear. Herein, combining the phase equilibrium experiments, advanced solid characterization methods, and theoretical calculations, we constructed a cyclic work diagram of LADH-Cl for lithium capture from aqueous solution, where the reversible (de)hydration and (de)intercalation induced phase evolution of LADH-Cl dominates the apparent lithium “adsorption–desorption” behavior. It is found that the real active ingredient in LADH-Cl type lithium sorbents is a dihydrated LADH-Cl with an Al:Li molar ratio varying from 2 to 3. This reversible process indicates an ultimate reversible lithium (de)intercalation capacity of ∼10 mg of Li per g of LADH-Cl. Excessive lithium deintercalation results in the phase structure collapse of dihydrated LADH-Cl to form gibbsite. When interacting with a concentrated LiCl aqueous solution, gibbsite is easily converted into lithium saturated intercalated LADH-Cl phases. By further hydration with a diluted LiCl aqueous solution, this phase again converts to the active dihydrated LADH-Cl. In the whole cyclic progress, lithium ions thermodynamically favor staying in the Al–OH octahedral cavities, but the (de)intercalation of lithium has kinetic factors deriving from the variation of the Al–OH hydroxyl orientation. The present results provide fundamental knowledge for the rational design and application of LADH-Cl type lithium sorbents.
Abstract	Lithium aluminumlayered double hydroxide chlorides (LADH-Cl) havebeen widely used for lithium extraction from brine. Elevation of theperformances of LADH-Cl sorbents urgently requires knowledge of thecomposition–structure–property relationship of LADH-Clin lithium extraction applications, but these are still unclear. Herein,combining the phase equilibrium experiments, advanced solid characterizationmethods, and theoretical calculations, we constructed a cyclic workdiagram of LADH-Cl for lithium capture from aqueous solution, wherethe reversible (de)hydration and (de)intercalation induced phase evolutionof LADH-Cl dominates the apparent lithium “adsorption–desorption”behavior. It is found that the real active ingredient in LADH-Cl typelithium sorbents is a dihydrated LADH-Cl with an Al:Li molar ratiovarying from 2 to 3. This reversible process indicates an ultimatereversible lithium (de)intercalation capacity of ∼10 mg ofLi per g of LADH-Cl. Excessive lithium deintercalation results inthe phase structure collapse of dihydrated LADH-Cl to form gibbsite.When interacting with a concentrated LiCl aqueous solution, gibbsiteis easily converted into lithium saturated intercalated LADH-Cl phases.By further hydration with a diluted LiCl aqueous solution, this phaseagain converts to the active dihydrated LADH-Cl. In the whole cyclicprogress, lithium ions thermodynamically favor staying in the Al–OHoctahedral cavities, but the (de)intercalation of lithium has kineticfactors deriving from the variation of the Al–OH hydroxyl orientation.The present results provide fundamental knowledge for the rationaldesign and application of LADH-Cl type lithium sorbents.
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Volume Number	4
DOI	10.1021/acsmaterialsau.3c00063
PubMed Central reference number	PMC10786131
Issue Number	1
PubMed reference number	38221919
Journal	ACS Materials Au [ACS Mater Au]
e-ISSN	26942461
Language	English
Publisher	American Chemical Society
Publisher Date	2023-10-06
Access Restriction	Open
Rights License	Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/). © 2023 The Authors. Published by American Chemical Society
Subject Keyword	lithium sorbent LADH-Cl phase evolution hydration intercalation deintercalation
Content Type	Text
Resource Type	Article
Subject	Materials Chemistry Biomaterials Polymers and Plastics Electronic, Optical and Magnetic Materials