Engineering Porous Quasi‐Spherical Fe−N−C Nanocatalysts with Robust Oxygen Reduction Performance for Zn‐Air Battery Application

Abstract

AbstractThe accessibility to highly active oxygen reduction reaction (ORR) catalysts with low cost is a priority for the rapid industrialization of Zn‐Air batteries. Herein, we propose a facile engineering synthesis of high‐activity quasi‐spherical Fe−N−C ORR nanocatalysts by chemical self‐assmbly. The morphological and structural features of the materials have been fully characterized. The synchrotron radiation techniques reveal that the targeted Fe−N−PQS‐900 with highly exposed Fe−Nx active sites well dispersed on the N‐rich micro‐nano carbon framework, endowing them with efficient access to oxygeneous species. The electrochemical measurements show its superior ORR catalytic performance to the commercial Pt/C catalyst, including a more positive half‐wave potential, smaller Tafel slope, better methanol‐tolerance capability, and more sustainable cycloability as well. An assembled Zn‐Air battery using the Fe−N−PQS‐900 as the cathode catalyst shows a specific capacity of 798 mAh g−1 with a power density of 114 mW cm−2 and an energy density of 958 Wh kg−1, enabling this non‐precious metal electrocatalyst very competitive in metal air fuel cell applications.