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

Area of Science:

• Materials Science
• Electrochemistry
• Chemical Engineering

Background:

• Growing demand for lithium-ion batteries in electric vehicles and energy storage necessitates sustainable lithium extraction methods.
• Geothermal brines represent an abundant, alternative source of lithium.
• Electrochemical intercalation offers a selective and chemical-free approach to lithium extraction.

Purpose of the Study:

• To design an economically feasible electrochemical process for selective lithium extraction from geothermal brine.
• To purify lithium chloride and convert it to battery-grade lithium hydroxide.
• To assess the techno-economic feasibility of the proposed lithium extraction technology.

Main Methods:

• Utilized electrochemical intercalation materials for selective lithium extraction from Salton Sea geothermal brine.
• Employed bipolar membrane electrodialysis for purification of lithium chloride and conversion to lithium hydroxide.
• Conducted techno-economic assessments using a parametric model.

Main Results:

• Achieved selective lithium extraction and purification from geothermal brine.
• Converted lithium chloride to battery-grade lithium hydroxide (>99.5% purity).
• Estimated the levelized cost of lithium hydroxide production at 4.6 USD/kg with a 0.5-year electrode lifespan.

Conclusions:

• The developed electrochemical process is a promising, chemical-free method for lithium extraction from alternative aqueous sources.
• The technology demonstrates economic feasibility for producing high-purity lithium hydroxide.
• This approach supports sustainable lithium sourcing for the growing battery market.