Engineering Spin-Electronic Coupling at Fe Cluster/Single-Atom Interfaces via p-Block Modulation for Zn-Air Batteries

Area of Science:

• Electrochemistry and Materials Science
• Catalysis for Energy Storage

Background:

• Iron-nitrogen-carbon (Fe-N-C) single-atom catalysts are promising for zinc-air batteries (ZABs).
• Oxygen reduction reaction (ORR) kinetics are limited by strong intermediate binding at FeN4 sites.

Purpose of the Study:

• To develop a novel heterostructured catalyst to overcome kinetic limitations in ZABs.
• To improve the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity.

Main Methods:

• Fabrication of a heterostructured catalyst (FeAC/SbFeNC) with sub-nanometer Fe clusters coupled to Sb and Fe sites on N-doped carbon.
• Utilized operando spectroscopic analyses and first-principles calculations.
• Tested catalyst performance in aqueous and quasi-solid-state ZABs.

Main Results:

• Sb acts as an electronic modulator, redistributing charge and quenching magnetic moments via 5p-3d hybridization.
• Coupled electronic-spin modulation significantly lowers ORR energy barriers for O-O bond cleavage and *OH desorption.
• Achieved a peak power density of 244.6 mW cm⁻² and 2300 h lifespan in aqueous ZABs.
• Demonstrated excellent performance in quasi-solid-state ZABs, including 1.12 Ah capacity and 600 h operation at -40°C.

Conclusions:

• The FeAC/SbFeNC catalyst exhibits enhanced bifunctional activity for ZABs.
• Synergistic interplay between p-block electronic/spin modulation and metal clusters is an effective strategy to overcome ORR limitations.
• This approach offers a pathway for developing high-performance, durable ZABs for demanding applications.