Novel LiAlO2 Material for Scalable and Facile Lithium Recovery Using Electrochemical Ion Pumping

In this study, alpha-LiAlO2 was investigated for the first time as a Li-capturing positive electrode material to recover Li from aqueous Li resources. The material was synthesized using hydrothermal synthesis and air annealing, which is a low-cost and low-energy fabrication process. The physical characterization showed that the material formed an alpha-LiAlO2 phase, and electrochemical activation revealed the presence of AlO2* as a Li deficient form that can intercalate Li+. The AlO2*/activated carbon electrode pair showed selective capture of Li+ ions when the concentrations were between 100 mM and 25 mM. In mono salt solution comprising 25 mM LiCl, the adsorption capacity was 8.25 mg g(-1), and the energy consumption was 27.98 Wh mol Li-1. The system can also handle complex solutions such as first-pass seawater reverse osmosis brine, which has a slightly higher concentration of Li than seawater at 0.34 ppm.

Automated summary

In this study, alpha-LiAlO2 was used as a Li-capturing positive electrode material to recover Li from aqueous Li resources. The material synthesis was cost-effective and low-energy. It showed selective capture of Li+ ions in the concentration range of 100 mM to 25 mM. The system demonstrated the ability to handle complex solutions such as seawater reverse osmosis brine.