465875 Advancement in High Capacity Adsorbent Materials for Lithium Recovery from Secondary Resources
One of the alternative ways offered to ensure a steady flow of Li supply is through its recovery from all viable resources such as brine pools, seawater, coal ash, and industrial wastes. However, existing technologies are not designed to recover Li from alternative resources, which typically contain low Li+ levels in the presence of more abundant interfering cations. Among the known processes, adsorption is considered as one of the simplest and most promising methods. The issue on highly selective Li+ capture can be addressed by using adsorbents with Li ion (Li+) sieving capability and/or ion recognition property.
While the potential of inorganic lithium ion sieves (LIS) and organic crown ethers (CEs) as Li+ adsorbents have been known for several decades, their application in actual systems are yet to be fully materialized. The hurdle of employing these materials primarily stems from their physical forms (i.e. either as powder or viscous fluids), which are prone to physical loss if directly used as adsorbents. Herein, the research status and progress on the development of advanced materials with high capacity and selectivity for Li+ capture are presented. Particularly, various synthesis routes and solutions to render the LIS and CEs stable, recyclable, and applicable for long term use (i.e. continuous Li recovery application in actual systems) are discussed. Immobilization and multi-step functionalization routes using different supports (i.e. polymers, inorganic nanomaterials, etc.) processed into different configurations (i.e. nanofibers, membranes, forms, etc.) as composite Li+ adsorbents are highlighted. Their potential application in actual systems are also demonstrated.
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2009-0093816) and Ministry of Science, ICT and future Planning (2015R1A2A1A15055407).