A flexible porous electrospun carbon nanofiber cathode catalyst for rechargeable liquid and flexible Zn-air batteries

Exploring flexible, porous, efficient, and stable cathodic electrocatalysts is crucial for the development of ZABs. In this study, an effective porous and flexible carbon nanofiber catalyst (Fe-ZCNF) was successfully constructed via electrospinning. PAN was used as the spinning substrate material, and hemin was incorporated to create the main active sites, while a NaCl molten salt-assisted ZIF-8 templating strategy was employed to form a connected pore structure. The Fe-ZCNF possesses an interconnected hierarchical porous structure and a high specific surface area of 1035.5 m 2  g −1 . Compared with commercial Pt/C (20 wt%), the E 1/2  = 0.88 V vs . RHE for ORR of Fe-ZCNF shifted positively by 20 mV, and a significant improvement in stability was observed. The ZABs assembled using Fe-ZCNF as the cathode exhibits excellent performance, with an OCV of 1.59 V and a power density of 179.2 mW cm −2 , which are superior to those of Pt/C + RuO 2 , along with a cycling stability of up to 200 h. Additionally, Fe-ZCNF can be used as the air cathode for FZABs, demonstrating high specific capacity and good cycling stability under different bending conditions. This work provides valuable insights into the design of flexible catalysts, potentially advancing the development of flexible electronic devices.