Thermally assisted efficient electrochemical lithium extraction from simulated seawater

Area of Science:

• Electrochemistry
• Materials Science
• Sustainable Energy

Background:

• Seawater contains abundant lithium, crucial for future energy demands.
• Current electrochemical lithium extraction methods are inefficient in low-concentration seawater.
• High sodium-to-lithium ratios in seawater pose a challenge for selective extraction.

Purpose of the Study:

• To investigate the effect of temperature on electrochemical lithium extraction from seawater.
• To enhance the kinetics and efficiency of lithium extraction at low concentrations.
• To develop a sustainable and energy-efficient process for lithium recovery from seawater.

Main Methods:

• Electrochemical extraction experiments at varying temperatures and lithium concentrations.
• Material characterization and mechanistic analysis of lithium intercalation and diffusion.
• Demonstration of a thermally assisted electrochemical process with integrated thermal energy harvesting.
• Coupling with a thermal-driven membrane process for freshwater production.

Main Results:

• Lithium extraction capacity and rate significantly increase with elevated temperatures (60°C).
• Improved extraction kinetics observed at low lithium concentrations (< 3 mM) and high Na+/Li+ ratios (>1000).
• Achieved rapid (36.8 mg g-1 day-1) and selective (51.79% purity) lithium extraction from simulated seawater.
• Demonstrated low electrical energy consumption (11.3-16.0 Wh mol-1 Li) and freshwater co-production (13.2 kg m-2 h-1).

Conclusions:

• Thermally assisted electrochemical extraction enhances lithium recovery from seawater by boosting kinetics.
• The process is energy-efficient, utilizing low-grade thermal energy.
• Co-production of freshwater adds value and improves overall process sustainability.
• This method presents a viable strategy for large-scale lithium mining from seawater.