Designing FeCo-NC-Based Air Cathode for Sustained Zn-Air Flow Batteries Through Equipping Electrocatalyst with...

Area of Science:

• Electrochemistry
• Materials Science
• Energy Storage

Background:

• Zinc-air flow batteries (ZnAFB) are crucial for large-scale energy storage.
• Improving ZnAFB performance hinges on advanced cathode electrocatalysts and air cathode infrastructure.

Purpose of the Study:

• To develop a highly active and durable FeCo-NC-based air cathode for ZnAFB.
• To investigate the catalytic mechanism and interfacial water behavior at the electrode surface.

Main Methods:

• Fabrication of a Fe7Co3@Fe-N3&Co-N3 catalyst (Fe8Co2@FeCo-NC) on an Fe-NC support.
• Utilized ab initio molecular dynamics (AIMD) and in situ Raman spectroscopy to study interfacial water.
• Assembled and tested Zn-air batteries (ZnAB) and ZnAFB devices.

Main Results:

• The Fe8Co2@FeCo-NC catalyst demonstrated enhanced bifunctional catalytic activity and reaction kinetics.
• AIMD and Raman spectroscopy revealed improved interfacial water management, facilitating faster intermediate transfer.
• The ZnAFB achieved a high power density of 208 mW cm-2 and a discharge capacity of 56 mAh cm-2.
• Exceptional durability was observed, with uninterrupted operation for 469 hours at 28 mAh cm-2.

Conclusions:

• The FeCo-NC air cathode significantly boosts ZnAFB performance and longevity.
• Optimized interfacial water dynamics are key to efficient electrocatalysis in ZnAFB.
• This work presents a promising low-cost catalyst for next-generation energy storage systems.