Background
Dr. Thomas C. Underwood and his team have developed a technology by which brine phase Li+ ions are converted directly to Li metals through electromagnetic-enhanced electroreduction, which is available for licensing. Dr. Underwood is an assistant professor in the Department of Aerospace Engineering and Engineering Mechanics at UT Austin with primary interests in space propulsion, non-equilibrium reacting flows, reactive transport, plasma wave interactions, plasma chemistry, and optical diagnostics. The focus of his work has broad applicability to emerging technologies within aerospace engineering, hypersonic applications, photonics, and chemical separation/recovery. Dr. Underwood has authored numerous journal publications on these subjects over the past nine years.
Invention
The developed technology overcomes many of the current limitations of existing Li extraction technologies (evaporative, non-evaporative) used to recover Li metals from brines—namely low/slow recovery, poor selectivity, environmental issues, high costs, use of reagents, fouling, and processing requirements. This Li electroreduction technology allows for the direct extraction of Li metals from Li brines (geothermal, produced subsurface formation waters from oil reservoirs, etc.) with Li+ concentrations ranging from ~10-1000 ppm.
Electromagnetic forces drive Li ions towards a cathode to reduce free Li+ to Li metal through controlled electromagnetic forces. The electromagnetically driven advection process increases the packing density of the Li(s) dendrite on the cathode, improving cation portioning in the brine based on charge and mass. The technology allows the cathode to accumulate Li-metal dendrites via electroreduction, and then the Li metal is extracted by removing the Li(s) from the cathode. To prevent an exothermic reaction between the Li(s) and water and to increase the Faradaic efficiency of the reaction, the constructed electrochemical cell immerses the cathode in a Li-selective organic solvent (e.g., diethyl carbonate).
The system shows the potential to increase recovery rates to ~ 0.01-0.2 g/cm2/hr, requires no reagents (such as those needed in non-evaporative recovery techniques), and eliminates the use of freshwater (required in evaporative techniques). The developed Li extraction process has application not only for the domestic extraction, separation, and processing of Li from brines for use in Lithium-ion battery construction, but can also be used to upgrade Li+ from Li-salt products (e.g., LiCl, Li2CO3) created by other techniques into Li metals, and also shows potential to convert rare earth oxides to rare earth metals.
