Regulating atomic Fe/Cu dual sites with unsymmetrical Fe-N6 and Cu-N1S2 coordination for promoting bifunctional oxygen electrocatalysis in advanced zinc-air batteries

Dual-metal single-atom catalysts with heteronuclear active sites exhibit superior oxygen catalysis performance than their single-atom counterparts, facilitating the practical applications in advanced electrochemical energy devices. Herein, a Fe-Cu dual-metal single-atom catalyst with Fe-N6 and Cu-N1S2 coordination environment (FeCu-DSAs/NSC) is reported. Due to the synergism of bimetallic active sites and asymmetric heteroatom coordination, the resultant FeCu-DSAs/NSC displays better bifunctional catalytic performance (a small potential gap between the Eη10 and E1/2, ΔE=0.647 V) when compared with the counterparts (Pt/C+IrO2 and Cu-ISAs/NSC), as well as surpassing most of bifunctional metal atom-based catalysts reported to date. As expected, FeCu-DSAs/NSC based rechargeable zinc-air battery shows remarkable superiority than commercial Pt/C+IrO2 benchmark, resulting in a high peak power density (230.66 mW cm−2), open-circuit voltage (1.464 V) and long-term cycling stability (up to 350 h at 10 mA cm−2).