Li1−xNi0.33Co1/3Mn1/3O2/Ag for electrochemical lithium recovery from brine

With the heightened global demand for lithium, more energy-efficient processes with fast Li+ production rates are essential for sustainable Li+ supply. Electrochemical Li+ recovery is a promising method that could satisfy these process necessities. However, its success requires highly effective electrodes that could selectively capture Li+ at a competitive uptake capacity with minimal energy requirement. Delithiated Li1−xNi1/3Co1/3Mn1/3O2 (NCM) paired with silver (Ag) is introduced as a new electrochemical system for Li+ recovery from brine. NCM is characterized by its high Li+ selectivity and stability in aqueous environment. At an applied current in brine, NCM was able to intercalate Li+ into its lattice while the Ag captured the Cl− counter-ion. Reversal of the current in a receiving solution prompted the release of LiCl. Under optimal conditions (i = ±0.25 mA cm−2), NCM can produce 96.4% pure Li+ from brine by expending 2.60 W·h mol−1 Li+. The NCM/Ag was able to perform consistently and produce an enriched LiCl solution in cycled operations. These promising results indicate that NCM/Ag can be developed as a high-throughput Li+ mining process with low energy requirement.