Highly Reversible Zn-Air Batteries Enabled by Tuned Valence Electron and Steric Hindrance on Atomic Fe-N4-C Sites

Huanran Zheng; Danni Deng; Xinran Zheng; Yingbi Chen; Yu Bai; Mengjie Liu; Jiabi Jiang; Haitao Zheng; Yuchao Wang; Jinxian Wang; Peiyao Yang; Yu Xiong; Xiang Xiong; Yongpeng Lei

doi:10.1021/acs.nanolett.4c01078

Highly Reversible Zn-Air Batteries Enabled by Tuned Valence Electron and Steric Hindrance on Atomic Fe-N₄-C Sites

Nano Lett. 2024 Apr 17;24(15):4672-4681. doi: 10.1021/acs.nanolett.4c01078. Epub 2024 Apr 8.

Authors

Affiliations

¹ State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, P. R. China.
² College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China.

PMID: 38587873
DOI: 10.1021/acs.nanolett.4c01078

Abstract

The bifunctional oxygen electrocatalyst is the Achilles' heel of achieving robust reversible Zn-air batteries (ZABs). Herein, durable bifunctional oxygen electrocatalysis in alkaline media is realized on atomic Fe-N₄-C sites reinforced by Ni_xCo_3-xO₄ (Ni_xCo_3-xO₄@Fe₁/NC). Compared with that of pristine Fe₁/NC, the stability of the oxygen evolution reaction (OER) is increased 10 times and the oxygen reduction reaction (ORR) performance is also improved. The steric hindrance alters the valence electron at the Fe-N₄-C sites, resulting in a shorter Fe-N bond and enhanced stability of the Fe-N₄-C sites. The corresponding solid-state ZABs exhibit an ultralong lifespan (>460 h at 5 mA cm^-2) and high rate performance (from 2 to 50 mA cm^-2). Furthermore, the structural evolution of Ni_xCo_3-xO₄@Fe₁/NC before and after the OER and ORR as well as charge-discharge cycling is explored. This work develops an efficient strategy for improving bifunctional oxygen electrocatalysis and possibly other processes.

Keywords: Zn−air battery; single-atom catalysts; steric hindrance; valence electron.