Graphite Nanoarrays-Confined Fe and Co Single-Atoms within Graphene Sponges as Bifunctional Oxygen Electrocatalyst for Ultralong Lasting Zinc-Air Battery

• Published in: ACS applied materials & interfaces Vol. 12; no. 36; pp. 40415 - 40425
• Main Authors: Chen, Chang, Li, Yifan, Cheng, Dan, He, Hua, Zhou, Kebin
• Format: Journal Article
• Language: English
• Published: American Chemical Society 09.09.2020
• Subjects: air; batteries; cathodes; commercialization; electrochemistry; electron transfer; Energy, Environmental, and Catalysis Applications; graphene; oxygen; oxygen production; long lifetime; single-atom; oxygen evolution reaction; zinc-air battery; oxygen reduction reaction; bifunctional oxygen electrocatalyst
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.0c12801

The inferior stability of bifunctional oxygen electrocatalysts in the air cathode is one of the main obstacles that impedes the commercialization of zinc-air batteries (ZABs). This work describes a self-assembly technique combined with subsequent calcination to prepare a bifunctional oxygen electrocatalyst of graphite nanoarrays-confined Fe and Co single-atoms within graphene sponges (FeCo-NGS). Specifically, graphene sponges overspread with graphite nanoarrays as a structure regulation, which can prevent the metal single-atoms from aggregating and accelerate the mass/electron transfer, provides a guarantee for the long-term operation. Furthermore, M-N4 (M = Fe/Co) as the intrinsic activity regulation can effectively drive the heterogeneous oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic processes. Thanks to the rationally designed regulations, FeCo-NGS shows both extraordinary electrocatalytic activity for ORR and OER, even outperforming commercial Pt/C and IrO2. Remarkably, ZABs with FeCo-NGS air cathode demonstrate a record-breaking cycle lifetime of more than 1500 h (over 9000 cycles) at 10 mA cm–2 with a small charge–discharge gap.