Fe₃ SnC@CNF: A 3 D Antiperovskite Intermetallic Carbide System as a New Robust High-Capacity Lithium-Ion Battery...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing advanced anode materials is crucial for improving lithium-ion battery performance.
• Intermetallic compounds offer potential for high energy density but often face challenges with stability and conductivity.

Purpose of the Study:

• To investigate the potential of a 3D intermetallic anti-perovskite carbide, Fe3SnC, as a lithium-ion battery anode.
• To enhance the electrochemical performance of Fe3SnC by synthesizing it as a composite with conducting carbon nanofibers (CNF).

Main Methods:

• In-situ synthesis of Fe3SnC@CNF composite via electrospinning and pyrolysis.
• Electrochemical testing including cyclic voltammetry, galvanostatic cycling, and electrochemical impedance spectroscopy.
• First-principles density functional theory (DFT) calculations to understand lithium ion incorporation.

Main Results:

• Single-phase Fe3SnC exhibited a reversible capacity of 426 mAh g⁻¹, while the Fe3SnC@CNF composite reached 600 mAh g⁻¹.
• The Fe3SnC@CNF composite demonstrated excellent cycling stability, retaining 96% capacity after 1000 cycles.
• High rate capability was observed, with 500 mAh g⁻¹ delivered at 2 A g⁻¹, and Li ion diffusion was enhanced by a factor of two compared to single-phase Fe3SnC.
• DFT calculations revealed favorable sites for Li atom incorporation and associated strain within the Fe3SnC unit cell.

Conclusions:

• The Fe3SnC@CNF composite is a promising anode material for high-performance lithium-ion batteries.
• The carbon nanofiber matrix effectively enhances the conductivity and stability of the Fe3SnC material.
• The study provides insights into the lithium storage mechanism in Fe3SnC through experimental and computational methods.