By: Mimi Martinez
Lithium has secured an unshakable position in the global energy transition. As electrification and decarbonization accelerate, the demand for lithium is skyrocketing, with projections reaching 1,607,000 tons by 2050. As part of an attempt to steer the world towards more sustainable practices, it is important that lithium extraction is conducted with the least invasive and most environmentally friendly practices.
Among the various lithium sources, salt-lake brine, seawater, mineral ores, and spent lithium-ion batteries, salt-lake brines have emerged as a cornerstone for global lithium supply due to their high lithium content and accessibility. Sustainably extracting lithium from these environments and resources is of the utmost importance. Current solvent extraction methods face significant limitations, including extractant loss and low separation efficiency, which hinder the sustainable scaling of lithium recovery.
A new study[i] introduces a method to extract lithium from one of its most common sources, salt-lake brine, using an oil-in-water Pickering emulsion stabilized by silica (SiO₂) nanoparticles with both water and oil-loving surfaces. The technology effectively confines tributyl phosphate (TBP) within the oil phase.
Through the Pickering method, the small spaces between the silica nanoparticles act as channels for lithium ions. Electric fields at the particle surfaces, combined with the confined spaces, help lithium ions lose water and move more easily.
This system dramatically enhances lithium extraction from salt-lake brine. The Pickering emulsion achieved a lithium recovery of 91.7%, a Li-Mg separation factor of 101.9 after just three extraction stages, and a Li⁺ mass transfer rate of 4.57 × 10⁻⁸ m/s. In comparison, conventional TBP systems only reached 52.8% recovery, a separation factor of 12 (a very low purification rate), and a transfer rate of 7.50 × 10⁻⁹ m/s (around 6 times slower than the Pickering method).
This new approach shows great promise for boosting lithium recovery and supporting a more sustainable supply to meet the growing demand from the global energy transition.
