As the global automotive industry moves toward electrification, demand for lithium batteries is expected to quintuple by the end of the century. The surging demand for batteries is forcing companies to look for new sources of lithium. A scientist at the University of Chicago’s Pritzker School of Molecular Engineering believes that the vast lithium metal we need is in the sea, waiting to be discovered.
Currently, about 75% of the world’s lithium comes from a mountainous area spanning Argentina, Bolivia and Chile, an area known as the “Lithium Triangle.” There, the metal is extracted by pumping brine into huge open-air basins and evaporating it over the course of a year. However, this long process is a major bottleneck in a world hungry for lithium, and while there are other sources, most have environmental costs.
Recently, the lab of Chong Liu, the Neubauer Family Assistant Professor at the Pritzker School of Molecular Engineering at the University of Chicago, is developing a new type of electrode that can extract the valuable element from seawater through a process called electrochemical intercalation. Although the work is still in its early stages, it may be one of the most sustainable ways to extract lithium anywhere. The process avoids the need for strong heat or strong acids and only yields the desired element through single-ion selectivity. At the molecular level, this is achieved by designing highly specific electrode materials that attract ions to the electrode while only capturing certain elements, trapping them.
However, this approach also has challenges. Because the concentration of lithium in seawater is quite low, about 0.2 parts per million, any extraction technology will need to be very efficient in order to extract lithium at a reasonable rate. In addition, in order to use these electrodes on an industrial scale, they will also need to be made of highly selective and durable materials.