Organometallic Polymer Constructed by Active Fe-C₁₂N₈ Centers for Boosting Sodium-Ion Storage

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Organic-metal coordination materials are promising for sodium-ion batteries but face limitations in active sites and structural stability.
• Developing robust and efficient electrode materials is crucial for advancing rechargeable battery technology.

Purpose of the Study:

• To design and synthesize novel organometallic polymer microspheres (Fe-PDA-220) for high-performance sodium-ion batteries.
• To investigate the structure-property relationships governing the electrochemical performance of these materials.

Main Methods:

• Synchronous polymerization and coordination reactions using phenylenediamine and iron ions (Fe3+/Fe2+) to form Fe-C12N8 active centers.
• Fabrication of organometallic polymer microspheres with a d-π conjugated structure.
• Electrochemical testing of the synthesized material as an electrode for sodium-ion batteries.

Main Results:

• Fe-PDA-220 exhibits enhanced structural stability due to distinctive Fe-C bonds and facilitated electron transfer via the π-d conjugation system.
• Achieved a high reversible capacity of 345 mAh g-1 at 0.1 A g-1.
• Demonstrated excellent long-term cycling stability, retaining 106 mAh g-1 at 1.0 A g-1 after 5000 cycles.

Conclusions:

• The d-π conjugated organometallic polymer microspheres provide a promising electrode material for sodium-ion batteries.
• The study highlights the potential of designing organometallic polymers to overcome performance limitations in organic electrode materials.
• Reversible redox reactions involving C=N groups and Fe ions contribute to the high electrochemical performance.