Electro-driven direct lithium extraction from geothermal brines to generate battery-grade lithium hydroxide

Abstract

As Li-ion batteries are increasingly being deployed in electric vehicles and grid-level energy storage, the demand for Li is growing rapidly. Extracting lithium from alternative aqueous sources such as geothermal brines plays an important role in meeting this demand. Electrochemical intercalation emerges as a promising Li extraction technology due to its ability to offer high selectivity for Li and its avoidance of harsh chemical regenerants. In this work, we design an economically feasible electrochemical process that achieves selective lithium extraction from Salton Sea geothermal brine and purification of lithium chloride using intercalation materials, and conversion to battery grade (>99.5% purity) lithium hydroxide by bipolar membrane electrodialysis. We conduct techno-economic assessments using a parametric model and estimated the levelized cost of LiOH•H₂O as 4.6 USD/kg at an electrode lifespan of 0.5 years. The results demonstrate the potential of our technology for electro-driven, chemical-free lithium extraction from alternative sources.