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In Situ Formation of Hierarchical Bismuth Nanodots/Graphene Nanoarchitectures for Ultrahigh‐Rate and Durable Potassium‐Ion Storage
Author(s) -
Zhao Yuanxin,
Ren Xiaochuan,
Xing Zhenjiang,
Zhu Daming,
Tian Weifeng,
Guan Cairu,
Yang Yong,
Qin Wenming,
Wang Juan,
Zhang Lili,
Huang Yaobo,
Wen Wen,
Li Xiaolong,
Tai Renzhong
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201905789
Subject(s) - materials science , nanodot , graphene , bismuth , anode , gravimetric analysis , chemical engineering , nanotechnology , potassium ion battery , potassium , electrode , chemistry , metallurgy , organic chemistry , engineering , lithium vanadium phosphate battery
Metallic bismuth (Bi) has been widely explored as remarkable anode material in alkali‐ion batteries due to its high gravimetric/volumetric capacity. However, the huge volume expansion up to ≈406% from Bi to full potassiation phase K 3 Bi, inducing the slow kinetics and poor cycling stability, hinders its implementation in potassium‐ion batteries (PIBs). Here, facile strategy is developed to synthesize hierarchical bismuth nanodots/graphene (BiND/G) composites with ultrahigh‐rate and durable potassium ion storage derived from an in situ spontaneous reduction of sodium bismuthate/graphene composites. The in situ formed ultrafine BiND (≈3 nm) confined in graphene layers can not only effectively accommodate the volume change during the alloying/dealloying process but can also provide high‐speed channels for ionic transport to the highly active BiND. The BiND/G electrode provides a superior rate capability of 200 mA h g −1 at 10 A g −1 and an impressive reversible capacity of 213 mA h g −1 at 5 A g −1 after 500 cycles with almost no capacity decay. An operando synchrotron radiation‐based X‐ray diffraction reveals distinctively sharp multiphase transitions, suggesting its underlying operation mechanisms and superiority in potassium ion storage application.