A multi-metal (Fe, Cu, Zn) coordinated hollow porous dodecahedron nanocage catalyst reduces oxygen in Zn-air battery

Yanan Pan ^a,1, Qi Yang ^{a, 1}, Xiaoying Liu ^a, Fan Qiu ^a, Junjie Chen ^a, Mengdie Yang ^a, Yang Fan ^a, Haiou Song ^b, and Shupeng Zhang ^{a, *}

¹ Y.N Pan and Q. Yang contributed equally to this work.

ABSTRACT

The coupling of low-cost, multiple metals and porous nanocarbon materials, aimed at replacing precious metals to enhance electrocatalytic oxygen reduction, is a critical challenge to some crucial research. This paper constructed a hollow dodecahedron nanocage catalyst (Fe₃O₄/CuNCs/ZnN_x-PHNC) by supporting copper nanoclusters, Fe₃O₄ nanoparticles, and Zn-N_X after sintering and annealing, using the coordination of ZIF-8 and doping copper and iron ions. We observed that the synergy of the multi-metals in the magnetically separable heterojunction catalyst induced an electron transfer and inhibits hydrogen peroxide formation, thus, improving its catalytic performance for oxygen reduction reaction. Its half-wave potential is as high as 0.832 V, and the Tafel slope is 54 mV/decade, superior to many non-precious metal catalysts in literature. The assembled Zn-air battery (ZAB) exhibits a maximum power density of 162 mW⸱cm^-2 and ultra-high stability of >500 h at a 5 mA⸱cm^-2 current density. The ZAB’s excellent performance also proves high development and practical application prospects.

A heterogeneous skeletonized nanocage catalyst Fe₃O₄/CuNCs/ZnN_x-PHNC loaded with bimetals was prepared by stirring at room temperature and annealed at high temperature with NaCl and KCl as protectants and stripping agents, respectively. The rich active sites produced by the synergistic action of various metals and hollow nanostructures enable the catalysts to show excellent ORR performance. When the prepared materials were used as liquid ZAB cathode catalysts, ZAB exhibited excellent performance with high OCV (1.45 V) and peak power density (162 mW⸱cm^-2). In addition, the ultra-high specific capacity (760 mA⸱h⸱g^-2) at a 10 mA⸱cm^-2 current density is far superior to that of the benchmark Pt/C-based catalyst. In addition, the Fe₃O₄/CuNCs/ZnN_x-PHNC-based ZAB was charged and discharged for more than 500 h at a 5 mA⸱cm^-2 current density, achieving high stability and high cycling performance. The excellent performance of the assembled FAZBs also proved their practical application potential as wearable flexible batteries. Overall, this study provides a feasible way to prepare efficient catalysts for ZABs cathodes to replace noble metal catalysts in practical applications.

原文链接：https://pubs.rsc.org/en/content/articlelanding/2024/ya/d4ya00295d 

柔性锌空电池可以支持计数器工作。 Video.mp4