Atomic-Level Tin Regulation for High-Performance Zinc-Air Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Designing efficient bifunctional electrocatalysts for aqueous rechargeable zinc-air batteries (a-r-ZABs) is challenging due to the trade-off between oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics.
• Precise control over atomic and electronic structures is essential for optimizing catalyst performance.

Purpose of the Study:

• To develop a novel trimetallic oxide catalyst, Sn-Co/RuO2, that enhances both ORR and OER activities for high-performance a-r-ZABs.
• To investigate the role of tin (Sn) in regulating the atomic and electronic properties of dual-active sites (Co for ORR, RuO2 for OER).

Main Methods:

• Synthesis of Sn-Co/RuO2 trimetallic oxide catalyst.
• Utilized theoretical calculations and advanced dynamic monitoring experiments to analyze catalyst behavior.
• Fabricated and tested a-r-ZABs using the developed catalyst, evaluating performance under various conditions and over extended periods.

Main Results:

• The Sn-Co/RuO2 catalyst demonstrated a low oxygen potential difference (ΔE) of 0.628 V, indicating excellent bifunctional activity.
• The catalyst exhibited remarkable stability, with negligible degradation after 200,000 ORR cycles and 20,000 OER cycles.
• a-r-ZABs based on Sn-Co/RuO2 showed superior lifespan (138 days at 5 mA cm-2) and stability (766.45 h at 10 mA cm-2), especially at low temperatures, outperforming Pt/C + IrO2 catalysts.

Conclusions:

• Tin (Sn) effectively regulates the atomic/electronic environment of Ru and Co sites, optimizing adsorption/desorption processes and enhancing bifunctional oxygen electrocatalysis.
• The developed Sn-Co/RuO2 catalyst represents a significant advancement for high-performance and durable aqueous rechargeable zinc-air batteries.
• This strategy offers a promising pathway for designing advanced electrocatalysts for next-generation energy storage devices.