We report a simple yet robust route to bifunctional electrocatalysts comprising FeNi and Co4N hybrid nanoparticles co-embedded within N-doped carbon nanosheets (denoted FeNi/Co4N-NCS) for rechargeable Zn-air batteries (ZABs) with high power density and capacity as well as outstanding cycling stability, markedly outperforming the Pt/C&IrO2 electrocatalyst counterpart. The as-crafted FeNi/Co4N-NCS electrocatalysts display outstanding bifunctional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity with a low overall oxygen electrode activity (ΔE = 0.664 V). Density functional theory (DFT) calculations reveal that the synergy of FeNi and Co4N reduces the rate-determining step (RDS) energy barrier, thereby greatly increasing electrocatalytic activity. The aqueous ZAB assembled with FeNi/Co4N-NCS delivers a high power density of 160 mW cm−2, large specific capacity of 812 mAh g−1Zn, and long cycling life of 1450 h at 5 mA cm−2. This study highlights an effective strategy to yield durable bifunctional electrocatalysts for metal-air batteries.
Bibliographical noteFunding Information:
This work is supported by the National Natural Science Foundation of China (52173207, 51674219), the Science Fund for Distinguished Young Scholars of Hunan Province of China (2023JJ10040), Natural Science Foundation of Hunan province (2022JJ30563), Outstanding Youth Fund Project of Hunan Provincial Department of Education (21B0119), the Science and Technology Innovation Program of Hunan Province (2022RC1077) and the Construct Program of the Key Discipline in Hunan Province is greatly acknowledged.
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- Bifunctional catalyst
- FeNi and CoN hybrid nanoparticles
- N-doped carbon nanosheets
- Schiff base polymer
- Zn-air battery