A Membrane-Free Rechargeable Seawater Battery Unlocked by Lattice Engineering

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Energy

Background:

• Seawater batteries offer sustainable, safe, and cost-effective energy storage.
• Current limitations include the lack of suitable anodes for rechargeable seawater batteries.

Purpose of the Study:

• To develop a highly active anode for rechargeable seawater batteries.
• To enable the reversible uptake of multiple cations from seawater electrolytes.

Main Methods:

• Lattice engineering of anatase titanium dioxide (TiO2).
• Density functional theory (DFT) calculations to understand charge storage mechanisms.
• Electrochemical performance testing in natural seawater and aqueous Na+ electrolyte.

Main Results:

• Engineered anatase TiO2 exhibits high activity for reversible cation uptake (Na+, Mg2+, Ca2+).
• Lattice expansion significantly reduces cation diffusion barriers within TiO2.
• Capacities increased by ~100x in seawater and ~200x in aqueous Na+ electrolyte.

Conclusions:

• Lattice-engineered TiO2 unlocks potential for high-performance rechargeable seawater batteries.
• This advancement brings practical aqueous seawater energy storage devices closer to reality.