FePc Coupled with FeNi/WxC Embeded in Leaf like Multistage Pore Carbon as Highly Efficient Bifunctional Electrocatalyst for Long Life Zinc-air Battery.

The development of oxygen reduction/evolution reaction (ORR/OER) bifunctional electrocatalysts with excellent electrocatalytic activity and stability is critical for Zinc-air batteries (ZABs), but remains challenging. Herein, NiFe-WNC with abundant multistage pore structure was prepared by chemical bath deposition and pyrolysis. FePc@NiFe-WNC bifunctional electrocatalyst was obtained by coupling dispersed FePc on it at room temperature. Experimental and theoretical calculations indicate that the electron injection from pyridine nitrogen of NiFe-WNC into FePc regulates the electronic structure of FeNx active site and then enhances the ORR catalytic activity. On the other hand, the electronic structure modulation of NiFe alloy by tungsten carbide in NiFe-WNC improves its OER electrocatalytic performance. All these contribute to the excellent ORR/OER electrocatalytic performance of FePc@NiFe-WNC with half-wave potential of 0.911 V, small potential gap (ΔE = 0.67 V), and good durability. The corresponding liquid ZABs delivers a specific capacity of 818 mAh/g and a long cycle life of up to 5000 h. Its quasi-solid-state battery shows a peak power density of up to 441 mW/cm, which can drive some electrical appliances, highlighting its extensive and safe application potential. This work offers a simple and feasible strategy to construct highly active and stable ORR/OER bifunctional electrocatalysts for developing high-performance ZABs.