Affiliation:
1. Engineering Research Center of the Ministry of Education for Advanced Battery Materials Hunan Provincial Key Laboratory of Value‐added Metallurgy School of Metallurgy and Environment Central South University Changsha 410083 P. R. China
Abstract
AbstractLow‐cost and high‐efficiency non‐precious metal‐based oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional catalysts are the key to promoting the commercial application of metal–air batteries. Herein, a highly efficient catalyst of Fe0.18Co0.82 alloy anchoring on the nitrogen‐doped porous carbon hollow sphere (FexCo1‐x/N‐C) is intelligently designed by spray pyrolysis (SP). The zinc in the SP‐derived metal oxides and metal‐organic framework volatilize at high temperature to construct a hierarchical porous structure with abundant defects and fully exposes the FeCo nanoparticles which uniformly anchor on the carbon substrate. In this structure, the coexistence of Fe0.18Co0.82 alloy and binary metal active sites (Fe‐Nx/Co‐Nx) guarantees the Fe0.2Co0.8/N‐C catalyst exhibiting an excellent half‐wave potential (E1/2 ═ 0.84 V) superior to 20% Pt/C for ORR and a suppressed overpotential (280 mV) than RuO2 for OER. Assembled rechargeable Zn–air battery (RZAB) demonstrates a promising specific capacity of 807.02 mAh g−1, peak power density of 159.08 mW cm−2 and durability without electrolyte circulation (550 h). This work proposes the design concept of utilizing an oxide core to in situ consume the porous carbon shell for anchoring metal active sites and construct defects, which benefits from spray pyrolysis in achieving precise control of the alloy structure and mass preparation.
Subject
Biomaterials,Biotechnology,General Materials Science,General Chemistry