Lithium Brines: Origin, Characteristics, and Global Distribution

Abstract Over the past two decades, considerable attention has been focused on lithium as a critical mineral resource. This is driven primarily by the unprecedented need for this element in moving the energy transition forward because of its utility in lithium-ion batteries for electric vehicles and energy storage. Lithium resources are found in three main types of deposits, but closed-basin brines are known to currently contain most of the global resources. Lithium resources are also present in sedimentary basin (oil field) and geothermal basin brines, although these are emerging and not yet produced at a commercial scale. Here we provide an update on the global state of lithium brine resources by type but with a focus on updating the ore deposit model for closed-basin lithium brines and introducing a seventh important characteristic for the formation of closed-basin lithium brines. This characteristic is hydro(geo)ology, which refers to the coupled role of hydrological basin characteristics and subsurface hydrogeological properties and their structure and distribution. Emerging lithium brine types are incorporated into our updated conceptual model, and case studies of two globally important lithium brine systems are also presented. Pegmatite and volcano-sedimentary lithium deposits are compiled to complete the lithium resource picture. Lastly, we consider lithium production over time and some guidelines for the exploration of closed-basin brines.