Engineering Mn-Nx sites on porous carbon via molecular assembly strategy for long-life zinc-air batteries

Zehui Wang; Daijie Deng; Huan Wang; Suqin Wu; Linhua Zhu; Li Xu; Henan Li

doi:10.1016/j.jcis.2023.09.174

Engineering Mn-N_x sites on porous carbon via molecular assembly strategy for long-life zinc-air batteries

J Colloid Interface Sci. 2024 Jan;653(Pt B):1348-1357. doi: 10.1016/j.jcis.2023.09.174. Epub 2023 Sep 29.

Authors

Zehui Wang¹, Daijie Deng¹, Huan Wang¹, Suqin Wu¹, Linhua Zhu², Li Xu³, Henan Li⁴

Affiliations

¹ Institute for Energy Research, School of Chemistry and Chemical Engineering, Jiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural Equipment, Jiangsu University, Zhenjiang 212013, China.
² College of Chemistry and Chemical Engineering, Key Laboratory of Water Pollution Treatment and Resource Reuse of Hainan Province, Hainan Normal University, Haikou 571158, China.
³ Institute for Energy Research, School of Chemistry and Chemical Engineering, Jiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural Equipment, Jiangsu University, Zhenjiang 212013, China. Electronic address: xulichem@ujs.edu.cn.
⁴ Institute for Energy Research, School of Chemistry and Chemical Engineering, Jiangsu Province and Education Ministry Co-Sponsored Synergistic Innovation Center of Modern Agricultural Equipment, Jiangsu University, Zhenjiang 212013, China. Electronic address: lhn@ujs.edu.cn.

PMID: 37801845
DOI: 10.1016/j.jcis.2023.09.174

Abstract

Nitrogen-coordinated manganese atoms on carbon materials denoted as MnNC, serve as the highly active non-precious metal electrocatalysts for oxygen reduction reaction (ORR) in zinc-air batteries (ZABs). Nonetheless, a significant challenge arises from the tendency of Mn atoms to aggregate during heat treatment, thereby compromising ORR performance in ZABs. In this work, the molecular assembly strategy based on the hydrogen bond interaction was employed to fabricate the MnNC electrocatalyst. This approach promotes the dispersion of Mn atoms, creating abundant Mn-N_x active sites. Furthermore, the resulting three-dimensional porous nanostructure, formed by molecular assembly, significantly enhances accessibility to the Mn-N_x active sites. The porous nanostructure not only shortens the diffusion path of reactants and charges but also improves mass transfer. The MnNC exhibits impressive ORR catalytic performance with a half-wave potential of 0.90 V (vs. RHE). The liquid-type ZAB based on MnNC displays a high specific capacity of 816.6 mAh/g and an extended charge-discharge cycle life of 1000 h. Quasi-solid-state ZAB based on MnNC can operate stably for 24 h. This work presents an effective strategy to synthesize transition metal-nitrogen-carbon (MNC) electrocatalysts tailored for long-life zinc-air battery.

Keywords: Hydrogen bond; Mn−N(x); Molecular assembly; Oxygen reduction reaction; Porous structure; Zinc-air battery.