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

In this study, α-LiAlO 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 α-LiAlO phase, and electrochemical activation revealed the presence of AlO* as a Li deficient form that can intercalate Li. The AlO*/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, and the energy consumption was 27.98 Wh mol Li. 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.