Realizing Fast Charge Diffusion in Oriented Iron Carbodiimide Structure for High-Rate Sodium-Ion Storage Performance

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Iron carbodiimide (FeNCN) exhibits covalent bonding, offering potential for advanced battery materials.
• Improving charge-transfer kinetics is crucial for enhancing sodium-ion battery performance.

Purpose of the Study:

• To synthesize oriented iron carbodiimide crystallites on a carbon substrate.
• To investigate the electrochemical performance of oriented FeNCN for sodium-ion storage.

Main Methods:

• Synthesis of oriented FeNCN crystallites with exposed {010} faces along the [001] direction on a carbon-based substrate.
• Electrochemical testing to evaluate Na-ion storage capacity and rate capability.

Main Results:

• The oriented FeNCN/S material demonstrated high Na-ion storage capacity (680 mAh g⁻¹ at 0.2 A g⁻¹) and excellent rate capability (360 mAh g⁻¹ at 20 A g⁻¹).
• Rapid charge-transfer kinetics and significant pseudocapacitance contribution were observed during conversion reactions.
• The specific orientation facilitated efficient Na-ion diffusion, supporting fast charge/discharge processes.

Conclusions:

• Rational structural design of metal carbodiimides, particularly oriented FeNCN, is key to achieving high electrochemical performance in sodium-ion batteries.
• The study provides insights into optimizing ion diffusion pathways for improved battery kinetics.