Tuning Work Function of Fe₂N@C Nanosheets by Co Doping for Enhanced Lithium Storage

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Transition metal nitrides (TMNs) show promise as lithium-ion battery (LIB) anode materials due to high capacity and conductivity.
• However, slow kinetics limit the rate performance of TMNs.
• Enhancing charge transfer and ion adsorption is crucial for improving LIB anode performance.

Purpose of the Study:

• To investigate the effect of cobalt (Co) doping on the properties of iron nitride (Fe2N) nanoparticles.
• To improve the work function of Fe2N to accelerate charge transfer and Li+ adsorption.
• To develop high-performance anode materials for LIBs.

Main Methods:

• Synthesis of Co-doped Fe2N nanoparticles anchored on honeycomb porous carbon foam (Co_x-Fe2N@C).
• Characterization of the electronic properties, including work function, of the synthesized materials.
• Electrochemical testing of Co_x-Fe2N@C as an anode material in LIBs.

Main Results:

• Co doping increased the work function of Fe2N from 5.23 eV to 5.67 eV (Co0.3-Fe2N@C) and 5.56 eV (Co0.1-Fe2N@C).
• The Co0.1-Fe2N@C electrode demonstrated a high specific capacity of 673 mA h g-1 at 100 mA g-1.
• Exceptional rate capability was observed, with 375 mA h g-1 at 5000 mA g-1.

Conclusions:

• Co doping is an effective strategy to enhance the electrochemical performance of Fe2N anode materials for LIBs.
• Optimized Co doping improves charge transfer kinetics and Li+ ion adsorption, leading to superior capacity and rate capability.
• This research presents a viable approach for designing advanced anode materials for high-performance LIBs.