CuFe alloys encapsulated in COF/MOF-derived 1D N-doped carbon nanofibers for boosting oxygen reduction reaction in highly efficient and durable zinc-air batteries

The exploration of non-precious metal electrocatalysts with superior oxygen reduction reaction (ORR) activity is a key but significant challenge for industrialization of rechargeable zinc-air batteries (ZABs). Herein, we rationally design an efficient and stable ORR catalyst based on CuFe alloy nanoparticles embedded in N-doped carbon nanofibers (CuFe-NHPC/CNFs) that derived from covalent organic framework/metal organic framework (COF/MOF) hybrids. Merited from strong synergistic effect of multiple active sites and advantage of three-dimensional hierarchical porous structure, CuFe-NHPC/CNFs electrode exhibits outstanding ORR activity in alkaline media, with a half-wave potential ( E 1/2 ​= ​0.88 ​V) and electrocatalytic stability (91 % current retention after 950 ​min). The above results reveal that overall performance of CuFe-NHPC/CNFs catalyst outperforms both commercial Pt/C and non-precious metal electrocatalysts reported recently. Impressively, aqueous ZAB driven by CuFe-NHPC/CNFs delivers a peak power density of 207 ​mW ​cm −2 and cycling stability over 300 ​h. Furthermore, corresponding solid-state ZAB displays appealing discharge capability, energy storage ability and flexibility, and can power wearable electronic devices such as safety warning lights under different deformation. This study offers a reliable idea for fabrication of low-cost and high ORR activity non-precious metal electrocatalysts from MOF/COF hybrids, which is important for development of efficient energy conversion and storage systems.