Ten thousand hour stable zinc air batteries via Fe and W dual atom sites
Yifan Li, Hanlin Wang, Chang Chen, Xuesong Xie, Yang Yang, Xuehai Tan, Keren Jiang, Ning Chen, Hao Zhang, Zhi Li
Abstract
Durable and highly active oxygen electrocatalysts are crucial to the large-scale application of rechargeable zinc-air batteries. Here we utilize the N4 unit in phthalocyanine molecule to trap the tungsten atoms scratched off from the tungsten carbide milling balls and place the obtained W-N4 unit adjacent to the Fe-N4 units from iron (Ⅱ) phthalocyanine, resulting in highly active Fe-N4/W-N4 diatomic sites with well-pronounced 3d−5d hybrid for efficient and durable oxygen electrocatalysis. The electron distribution of the Fe-N4 site is optimized by the neighboring W-N4 site, which facilitates the O2 activation and the desorption of *OH and enhances the catalytic activity of the Fe-N4 site. Meanwhile, the unsaturated 5 d orbitals and tunable valence of the W atoms could modulate the electronic state of the Fe species, prevent leaching, and further enhance the catalytic stability. The resulting zinc-air battery with Fe,W-N-C air cathode exhibits notable cycling stability and repeatability for over 10,000 h. This enhanced stability highlights the possibility of developing 5 d metal-boosted 3 d metal active sites for the fabrication of efficient oxygen electrocatalysts and stable zinc-air batteries. Long-lasting oxygen catalysts are crucial for rechargeable zinc-air batteries. Here, the authors report that placing tungsten atoms next to iron atoms within N4 units creates durable Fe-N4/W-N4 diatomic sites, enabling a zinc-air battery to cycle reliably for more than 10,000 h.