The recent advances and modification strategies of Li/Al-LDHs toward lithium extraction

Abstract

The soaring demand for lithium resources has driven increasing interest in extracting lithium from low-grade brines. Among available techniques, adsorption is considered the optimal method due to its efficiency and selectivity. Lithium‑aluminum layered double hydroxide (LiAl-LDHs) has emerged as the only commercially implemented adsorbent, owing to its high adsorption efficiency, excellent structural stability, and mild desorption conditions. Nevertheless, its inherently limited adsorption capacity remains a major constraint. Although extensive research has been devoted to modifying Li/Al-LDHs materials in recent years, a comprehensive and systematic review remains scarce. This study systematically investigates the correlation between the unique structure of Li/Al-LDHs and their adsorption mechanisms to elucidate structure-property relationships. Subsequently, a detailed analysis of adsorption processes and selectivity profiles is presented. Furthermore, an overview of common synthesis routes for Li/Al-LDHs is provided, highlighting the advantages and limitations of each approach. Modification strategies are reviewed to offer a theoretical framework for enhancing the capacity of LDHs-based adsorbents. Additionally, the pivotal role of powder loading technology in practical applications is discussed. Besides, the practicality and efficiency of regeneration techniques for Li/Al-LDHs are evaluated. Finally, the review concludes with a prospective analysis of future research directions and design strategies for Li/Al-LDHs. This work establishes a scientific foundation for designing high-performance Li/Al-LDHs, which are critical for advancing new energy technologies and safeguarding China's lithium resource security.