Fe-MOF-Derived Efficient ORR/OER Bifunctional Electrocatalyst for Rechargeable Zinc-Air Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Developing efficient bifunctional electrocatalysts for oxygen reduction and evolution reactions (ORR/OER) is crucial for high-performance metal-air batteries.
• Existing catalysts often face challenges in achieving both high activity and long-term durability.

Purpose of the Study:

• To fabricate a novel, highly efficient ORR/OER bifunctional electrocatalyst for rechargeable zinc-air batteries.
• To investigate the performance and durability of the synthesized material as a cathode.

Main Methods:

• Pyrolysis of a single-crystal Fe-MOF to create uniform FeS/Fe3C nanoparticles embedded in a porous N,S-dual doped carbon honeycomb-like composite (FeS/Fe3C@NS-C-900).
• Characterization of the material's structure and electrochemical properties.
• Testing the material as a cathode in rechargeable zinc-air batteries.

Main Results:

• The FeS/Fe3C@NS-C-900 composite exhibited a low potential gap (ΔE) of approximately 0.72 V.
• Achieved a competitive power density of 90.9 mW/cm² and a high specific capacity of 750 mAh/g.
• Demonstrated excellent cycling stability over 865 hours (1730 cycles) at 2 mA/cm².
• Two series-linked Zn-air batteries successfully powered a 2.4 V LED light.

Conclusions:

• The synthesized FeS/Fe3C@NS-C-900 composite demonstrates superior ORR/OER bifunctional electrocatalytic activity and durability.
• The honeycomb-like porous structure, synergistic effects of FeS and Fe3C, and N,S-codoped carbon contribute to the enhanced performance.
• This material shows significant potential for applications in portable electronic Zn-air battery devices.