Bioprocessing-Inspired Construction of Hierarchically Porous Structure and Phosphorus Doping in Fe-N-C for High-Performance Zinc-Air Battery
摘要
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are key cathode reactions in clean energy storage devices such as zinc–air batteries. However, their sluggish kinetics severely limit device efficiency and large-scale application. Currently, M–N–C catalysts are considered the most promising candidates, yet they still suffer from issues such as mass transport limitations and insufficient stability. Inspired by the dynamic regulation of organic–inorganic interfaces during the formation of biological materials, we developed a novel method using 1,3,5-trimethylbenzene (TMB) as a mediating molecule to dynamically regulate the organic-inorganic interface between templates and ZIF-8 precursors, achieving the micro-meso-macropores of ZIF-8, which synergistically enhanced mass transport and active site accessibility. Meanwhile, phosphorus doping modulated the electronic structure of the Fe centers, forming Fe-N-P active sites and thereby significantly enhancing both catalytic activity and stability. Electrochemical tests showed that HPZIF-8-FeNP5 exhibited excellent ORR performance in alkaline medium, with a half-wave potential of 0.8595~V (vs. RHE), outperforming commercial Pt/C while demonstrating good methanol tolerance and cycling stability. Furthermore, the catalyst also showed promising OER activity, with an over-potential of 284~mV at 10~mA~cm-2. When applied in a zinc–air battery, the device delivered a high open-circuit voltage (1.52~V), a high power density (227.4~mW~cm-2), and long-term cycling stability ($>$400~h), surpassing the Pt/C-RuO2 benchmark. This work provides a new material design strategy to advance rechargeable zinc-air battery technology, enabling efficient and durable energy storage.
