Review of recent advances in lithium extraction from subsurface brines

Lithium has been a critical metal for energy transition, mainly because of its application as an energy storage matrix, which has seen its demand increasing exponentially in the last decades. To supply the current demand chain and overcome the geographical and technological limitations of lithium extraction from Salt Lake brines, the present article investigates the possibility of lithium extraction from non-conventional resources, such as Oilfields and Geothermal brines. Thus, our investigation seeks to answer the following research questions: (1) Are there identified lithium-rich subsurface brine resources? (2) Could the conventional lithium extraction precipitation method be successfully applied to those resources? (3) What are the state-of-the-art of alternative technologies that can economically be applied for efficient lithium recovery from those subsurface brine resources? First, our investigation identifies and distributes geographically lithium-rich subsurface brine resources worldwide, with the American continent being abundant on Oilfield brine. Europe, on the other hand, was much more abundant in Geothermal water. The UK possesses lithium-rich oilfields at relatively low concentrations and highly enriched geothermal brine, with an abundance of other lithium-rich brine sites possible across Africa and Asia. Secondly, it was established through a critical evaluation that conventional precipitation methods are insufficient for lithium extraction when applied to subsurface brines. Thus, it leads us to survey the state-of-theart of novel extraction technologies with data from 1960 to the present, with the highest information density covering the last 22 years. Out of the reviewed extraction technologies, ion-sieve adsorbent and nanofiltration were found to be the best ally for lithium extraction from subsurface brine in the present and near future with low energy consumption, excellent lithium recovery, high extraction rate, outstanding selectivity, and forming adaptability.