Quest to Mine Seawater for Lithium Advances
Researchers at Japan’s Atomic Energy Agency have come up with a new method of processing seawater to extract lithium, an element that plays a key role in advanced batteries for electric vehicles and one that, if current predictions for the EV market prove accurate, could be in short supply before the end of the decade.
Writing in the new issue of the journal Desalination, Tsuyoshi Hoshino, a scientist at the JAEA’s Rokkasho Fusion Institute, proposed a method for recovering lithium from seawater using dialysis. Still years from commercialization, the system is based on a dialysis cell with a membrane consisting of a superconductor material. Lithium is the only ion in the seawater that can pass through the membrane, from the negative-electrode side of the cell to the positive-electrode side. The method “shows good energy efficiency and is easily scalable,” Hoshino writes.
Today a thriving industry extracts magnesium from seawater, but the economical production of lithium from the sea has proved elusive. The element is found in extremely low concentrations in the ocean and already has an established supply chain, mostly from salt lakes in South America.
If Hoshino’s method proves efficient and economical, it could transform a market that has seen lots of investment and supposed innovation in recent years but has remained stubbornly resistant to new technologies and new sources of supply. Most lithium is still recovered today in the way it has been for half a century: by evaporating brine collected from salt lakes in enclosed valleys in parts of Chile, Argentina, and Bolivia.
Predictions of lithium supply crunches have appeared with increasing frequency in recent years. Many analysts, though not all, believe that rising demand from makers of batteries for electric vehicles, particularly Tesla, whose forthcoming Gigafactory is expected to nearly double world lithium demand, is sure to strain supplies from traditional sources.