It remains a great challenge to develop high-efficient, low-cost and robustly stable bifunctional oxygen electrocatalysts for rechargeable metal-air batteries. Herein, we report a promising electrocatalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The electrocatalysts are composed of nanostructured FeNi alloy nanoparticles inlaid on N-doped carbon nanotubes (CNTs)-tangled porous carbon fibers (FeNi/N-CPCF). Benefiting from its hierarchically porous structures with bamboo-like CNTs grafted, and strong synergetic coupling between FeNi alloys and N-doped carbon species, the as-prepared FeNi/N-CPCF-950 demonstrates a half-wave potential of 0.867 V for ORR and a low operating potential of 1.585 V at 10 mA cm^-2 for OER in 0.1 M KOH, outperforming commercial Pt/C and RuO₂. Moreover, such bifunctioal catalyst endows the homemade zinc-air batteries with a high energy efficiency of 61.5%, small charge-discharge voltage gap of 0.764 V, and outstanding cycling performance (640 hours, 960 cycles) at 10 mA cm^-2 under ambient conditions.

开发用于可再充电金属空气电池的高效，低成本和鲁棒稳定的双功能氧电催化剂仍然是一个巨大的挑战。在本文中，我们报道了一种有希望的用于氧还原反应（ORR）和氧释放反应（OER）的电催化剂。电催化剂由镶嵌在N掺杂的碳纳米管（CNT）缠结的多孔碳纤维（FeNi / N-CPCF）上的纳米结构FeNi合金纳米颗粒组成。得益于FeNi / N-CPCF-950的分层多孔结构，其接枝了竹子状CNTs的分层多孔结构，以及FeNi合金与N掺杂碳物种之间的强协同耦合，显示出ORR和0.86 V的半波电势。在0.1 M KOH中的OER时，在10 mA cm ^-2时具有1.585 V的低工作电势，优于商用Pt / C和RuO₂。此外，这种双功能催化剂使自制的锌-空气电池在环境温度为10 mA cm ^-2时具有61.5％的高能效，0.764 V的小充放电电压间隙以及出色的循环性能（640小时，960个循环）。情况。