Fe-Single-Atom Incorporated Wood-Derived Anode with Fe─N─C/Fe₃C Structural Unit and Hollow Diffusion Sites for...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Sluggish sodium-ion (Na+) diffusion kinetics limit the rate capability and capacitance of anodes in sodium-ion batteries (SIBs).
• Developing efficient anode materials is crucial for advancing SIB technology.

Purpose of the Study:

• To engineer Fe single-atom active sites integrated with Fe3C species on wood-derived nanoporous carbon (WNC) for enhanced SIB anode performance.
• To investigate the synergistic effects of Fe─N4─O2 active sites and Fe3C species on Na+ diffusion and electrochemical properties.

Main Methods:

• Fabrication of Fe single-atom active sites (Fe─N4─O2) coupled with Fe3C species on a wood-derived nanoporous carbon (WNC) support.
• Electrochemical characterization including capacitive and charge-discharge studies to evaluate Na+ diffusion and migration energy.
• Theoretical calculations to determine Na+ migration energy barriers along diffusion paths.

Main Results:

• The Fe─N4─O2-WNC anode demonstrated a high discharge-specific capacity of 318 mAh g-1 at 50 mA g-1.
• Electrochemical analysis confirmed the role of Fe─N bonding in optimizing Na+ diffusion sites.
• Faster Na+ diffusion was observed through hollow sites, with Fe─N bond stretching during discharge cycles.

Conclusions:

• The Fe─N4─O2-WNC anode facilitates reversible Na+ conversion and diffusion, overcoming kinetic limitations in SIBs.
• The strategy of incorporating Fe single atoms on WNC provides a promising pathway for manufacturing advanced SIBs from renewable resources.
• The study highlights the potential of sodiophilic Fe─N sites for future battery development.