Lithium, a cornerstone of the global transition to green energy, is a strategic resource with far-reaching implications for economic development, environmental sustainability, and geopolitical dynamics. Extracting lithium from low-concentration brines – and especially from ultra-dilute sources such as seawater – remains one of the greatest technical challenges in lithium resource development.
Overcoming this hurdle would mark a major breakthrough in rebalancing global lithium supply and demand. Dr. Lan Weiguang, in collaboration with the Department of Chemistry at the NUS, has pioneered an advanced membrane-based technology for Direct Lithium Extraction (DLE) from seawater.
In this project, Dr. Lan introduced an innovative three-layer composite membrane structure, comprising an adsorption layer, a selective layer, and a ceramic support layer. Lithium lanthanum titanate (LLTO) is used as the active material to enable selective lithium ion enrichment, while the ceramic substrate ensures mechanical stability and scalability. Electrodialysis is employed as the driving force for ion separation.
Leveraging the advantages of this composite structure, Dr. Lan’s team successfully scaled the membrane and extraction system to pilot level – becoming the first team in China to develop a pilot-scale seawater DLE platform. Their system achieved over a 100-fold enrichment of lithium from seawater, with outstanding lithium – magnesium selectivity, representing a major step forward in the sustainable recovery of lithium from unconventional sources.
Dr. Lan Weiguang’s impact in the field of Direct Lithium Extraction (DLE) extends well beyond academia. In November 2018, he received the 2016 – 2018 Technology Award from the Inorganic Chemical Industry Science and Technology Awards Committee for pioneering a novel process using nanofiltration membranes to efficiently separate, enrich, and concentrate lithium from salt lake brine. This breakthrough marked the first successful application of nanofiltration membranes in DLE from salt lake brines to selectively separate monovalent metal ions. Dr. Lan led Suntar’s development of a complete salt lake DLE production line, integrating key process modules – including pretreatment, adsorption, magnesium-lithium separation, boron removal, lithium concentration, and lithium precipitation. China currently has an annual production capacity of 200,000 tonnes of lithium carbonate from salt lakes. Suntar has played a pivotal role, contributing to more than 13 salt lake DLE projects with a combined capacity exceeding 120,000 tonnes. Backed by field-validated, advanced technologies, Suntar has established itself as a market leader with clear advantages in both technical maturity and operational efficiency.