Nanopore Confinement of Electrocatalysts Optimizing Triple Transport for an Ultrahigh-Power-Density Zinc-Air Fuel Cell with Robust Stability.

Zhou, Tianpei; Shan, Huan; Yu, Hao; Zhong, Cheng'an; Ge, Jiankai; Zhang, Nan; Chu, Wangsheng; Yan, Wensheng et al. · Adv Mater · 2020

basic_science · Level V

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Abstract

Metal-air fuel cells with high energy density, eco-friendliness, and low cost bring significantly high security to future power systems. However, the impending challenges of low power density and high-current-density stability limit their widespread applications. In this study, an ultrahigh-power-density Zn-air fuel cell with robust stability is highlighted. Benefiting from the water-resistance effect of the confined nanopores, the highly active cobalt cluster electrocatalysts reside in specific nanopores and possess stable triple-phase reaction areas, leading to the synergistic optimization of electron conduction, oxygen gas diffusion, and ion transport for electrocatalysis. As a result, the as-established Zn-air fuel cell shows the best stability under high-current-density discharging (>90 h at 100 mA cm<sup>-2</sup> ) and superior power density (peak power density: >300 mW cm<sup>-2</sup> , specific power: 500 Wg<sub>cat</sub> <sup>-1</sup> ) compared to most reported non-noble-metal electrocatalysts. The findings will provide new insights in the rational design of electrocatalysts for advanced metal-air fuel cell systems.