The construction and design of highly efficient and inexpensive bifunctional oxygen electrocatalysts substitute for noble-metal-based catalysts is highly desirable for the development of rechargeable Zn-air battery (ZAB). In this work, a bifunctional oxygen electrocatalysts of based on ultrafine CoFe alloy (4-5 nm) dispersed in defects enriched hollow porous Co-N-doped carbons, made by annealing SiO₂ coated zeolitic imidazolate framework-67 (ZIF-67) encapsulated Fe ions. The hollow porous structure not only exposed the active sites inside ZIF-67, but also provided efficient charge and mass transfer. The strong synergetic coupling among high-density CoFe alloys and Co-N_x sites in Co, N-doped carbon species ensures high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity. First-principles simulations reveal that the synergistic promotion effect between CoFe alloy and Co-N site effectively reduced the formation energy of from O* to OH*. The optimized CoFe-Co@PNC exhibits outstanding electrocatalytic stability and activity with the overpotential of only 320 mV for OER at 10 mA·cm⁻² and the half-wave potential of 0.887 V for ORR, outperforming that of most recent reported bifunctional electrocatalysts. A rechargeable ZAB constructed with CoFe-Co@PNC as the air cathode displays long-term cyclability for over 200 h and high power density (152.8 mW·cm⁻²). Flexible solid-state ZAB with our CoFe-Co@PNC as the air cathode possesses a high open circuit potential (OCP) up to 1.46 V as well as good bending flexibility. This universal structure design provides an attractive and instructive model for the application of nanomaterials derived from MOF in the field of sustainable flexible energy applications device.

高效和廉价的双功能氧电催化剂替代贵金属基催化剂的构造和设计对于可再充电锌空气电池（ZAB）的开发是非常需要的。在这项工作中，一种基于超细CoFe合金（4-5 nm）的双功能氧电催化剂，分散在富含缺陷的中空多孔掺Co-N的碳中，是通过对SiO ₂包覆的沸石咪唑酸盐骨架67（ZIF-67）进行退火而制成铁离子。中空的多孔结构不仅暴露了ZIF-67内部的活性位，而且还提供了有效的电荷和质量传递。高密度CoFe合金与Co-N _x之间的强协同耦合Co，N掺杂的碳物种中的两个位点可确保较高的氧还原反应（ORR）和氧释放反应（OER）活性。第一性原理模拟表明，CoFe合金与Co-N部位之间的协同促进作用有效地降低了O *到OH *的形成能。优化的CoFe-Co @ PNC具有出色的电催化稳定性和活性，在10 mA·cm ^-2时，OER的超电势仅为320 mV ，ORR的半波电势为0.887 V，优于最新报道的双功能电催化剂。以CoFe-Co @ PNC为空气阴极构造的可充电ZAB具有200 h以上的长期循环能力和高功率密度（152.8 mW·cm ^-2））。以我们的CoFe-Co @ PNC作为空气阴极的柔性固态ZAB具有高达1.46 V的高开路电位（OCP）和良好的弯曲柔韧性。这种通用的结构设计为在可持续柔性能源应用设备领域应用源自MOF的纳米材料提供了有吸引力且具有启发性的模型。