Regulated electronic structure and improved electrocatalytic performances of S-doped FeWO4 for rechargeable zinc-air batteries

Abstract

The exploration of active and long-lived oxygen reduction reaction (ORR) catalysts for the commercialization of zinc-air batteries are of immense significance but challenging. Herein, the sulfur doped FeWO4 embedded in the multi-dimensional nitrogen-doped carbon structure (S-FeWO4/NC) was successfully synthesized. The doped S atoms optimized the charge distribution in FeWO4 and enhanced the intrinsic activity. At the same time, S doping accelerated the formation of reaction intermediates during the adsorption reduction of O2 on the surface of S-FeWO4/NC. Accordingly, the S-FeWO4/NC catalyst showed more positive half-wave potential (0.85 V) and better stability than that of the FeWO4/NC catalyst. Furthermore, the S-FeWO4/NC-based zinc-air battery exhibited considerable power density of 150.3 mW cm−2, high specific capacity of 912.7 mA h g−1, and prominent cycle stability up to 220 h. This work provides an assistance to the development of cheap and efficient tungsten-based oxygen reduction catalysts and the promotion of its application in the zinc-air battery.