Electrochemical Lithium Extraction from Brines and Electrochemical Production of Lithiated Transition Metal Oxides

Geothermal and other brines can contain large amounts of lithium, however, a commercially viable method to extract lithium from such brines remains limited. We have developed lithium-ion selective redox materials that are stable, even in chemically aggressive brines, and effectively extract lithium ions from brines and convert the lithium into LiOH via an electrochemical process. In one example, we use thick films of electrodeposited LiCoO2 due to the chemical stability of binder and conductive additive-free electrodeposited LiCoO2 in aggressive environments such as geothermal brines. Tested in a flow cell, the redox electrode shows remarkable lithium-ion selectivity (Li/Na>75), good structural stability in hot brine environment, and high coulombic lithium extraction efficiency. We further demonstrated that the redox membrane is most effective when cycled at high rate in its lithium deficient state. As part of my talk, I will include how we electrodeposit LiCoO2 and other transition metal oxides in highly and appropriately textured form to provide fast lithium insertion and deinsertion kinetics.