Se Vacancy Activated Bi2Se3 Nanodots Encapsulated in Porous Carbon Nanofibers for Aqueous Zinc and Ammonium Ion Batteries

• Published in: Advanced functional materials 2024-11, Vol.34 (48), p.n/a
• Main Authors: Long, Bei, Ma, Xinyang, Chen, Lijuan, Song, Ting, Pei, Yong, Wang, Xianyou, Wu, Xiongwei
• Format: Article
• Language: English
• Subjects: Activated carbon; aqueous zinc/ammonium ion batteries; Bi2Se3 nanodots; Bismuth; Carbon fibers; Design; Electrodes; high mass loading; long cyclic life; Nanofibers; Porous materials; Se vacancy; Selenium; Zinc
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202411430

Bismuth‐based materials show great potential in aqueous batteries. But it is difficult to design a bifunctional bismuth‐based material for zinc and ammonium ion batteries (ZIBs and AIBs). Herein, a electrospinning method followed by a selenization strategy is used to design Bi2Se3 nanodots embedded in porous carbon nanofibers. Experimental studies coupled with theoretical calculations prove that the designs of nanodot and Se vacancy improve the transfer and storage of Zn2+ and NH4+. Bi2Se3 nanodots are restricted to porous carbon nanofibers during cyclic test. An insertion‐type mechanism is revealed by ex situ characterizations. As a result, this well‐designed electrode (6 mg cm−2) offers high reversible capacities of 270 mA h g−1 in ZIBs and 192 mA h g−1 in AIBs at 0.05 A g−1 and long‐term cycle life (60% capacity retention at 10 A g−1 after 20 K cycles for ZIBs, 78% capacity retention at 2 A g−1 after 9 K cycles for AIBs). Remarkably, it still displays satisfactory performances even at an ultrahigh mass loading of 18 mg cm−2. Furthermore, Zn2+ and NH4+ full cells offer high reversible capacities of 120 and 90 mA h g−1 at 0.05 A g−1 respectively. This work provides a reference for designing a bifunctional electrode. Bifunctional Bi2Se3 NF electrodes are designed as insertion‐type anodes for Zn2+ and NH4+ storage. The designs of nanodot and Se vacancy enhance charge transfer and storage, proved by theoretical and experimental studies. Bi2Se3 NF displays satisfactory electrochemical performances even at an ultrahigh mass loading of 18 mg cm‐2. Significantly, Zn2+ and NH4+ full cells show great potential.