Decrypting Synergy of Alloy & Metal Nanoparticles Within Nitrogen-Doped Carbon Nanosheets for Zn-Air Batteries with Ultralong Cycling Stability.

The exploration of efficient, robust, and low-cost bifunctional electrocatalysts to drive the commercial application of Zn-air batteries (ZABs) is of great significance but still remains a challenge. Herein, a 1D coordination polymer (1D-CP) derived FeNi alloy & Co nanoparticles (NPs) co-implanted N-doped carbon nanosheets (FNC/NCS) is judiciously crafted and employed as a high-performance electrocatalyst for ultralong lifetime ZABs. The key to this strategy is the leveraging of metal-coordinated melamine to direct the pyrolysis of 1D-CP, enabling the in situ formation of well-dispersed FeNi alloy and Co NPs within the carbon matrix. The resulting FNC/NCS exhibits prominent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity with a small overall oxygen potential difference (ΔE = 0.68 V). Density functional theory (DFT) simulation demonstrates that the synergistic effect between FeNi alloy and Co NPs can reduce energy barriers, promote electron transfer, and optimize the formation of crucial intermediates, thereby largely boost ORR/OER activity of FNC/NCS. The FNC/NCS-assembled ZABs possess high specific capacity, large power density, and ultralong cycling life in both aqueous (> 3300 h) and solid-state (150 h) electrolytes. This work provides a viable strategy for 1D-CP-derived bifunctional electrocatalysts and dissects the synergistic effect between different metal species, affording significant guidance for the development of renewable energy materials.