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In Situ, Atomic‐Resolution Observation of Lithiation and Sodiation of WS 2 Nanoflakes: Implications for Lithium‐Ion and Sodium‐Ion Batteries
Author(s) -
Xu Yaobin,
Wang Ke,
Yao Zhenpeng,
Kang Joohoon,
Lam David,
Yang Dan,
Ai Wei,
Wolverton Chris,
Hersam Mark C.,
Huang Ying,
Huang Wei,
Dravid Vinayak P.,
Wu Jinsong
Publication year - 2021
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.202100637
Subject(s) - electrochemistry , lithium (medication) , materials science , intercalation (chemistry) , electrode , alkali metal , sodium ion battery , ion , sodium , battery (electricity) , chemical engineering , nanotechnology , inorganic chemistry , chemistry , metallurgy , medicine , organic chemistry , faraday efficiency , engineering , endocrinology , power (physics) , physics , quantum mechanics
WS 2 nanoflakes have great potential as electrode materials of lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs) because of their unique 2D structure, which facilitates the reversible intercalation and extraction of alkali metal ions. However, a fundamental understanding of the electrochemical lithiation/sodiation dynamics of WS 2 nanoflakes especially at the nanoscale level, remains elusive. Here, by combining battery electrochemical measurements, density functional theory calculations, and in situ transmission electron microscopy, the electrochemical‐reaction kinetics and mechanism for both lithiation and sodiation of WS 2 nanoflakes are investigated at the atomic scale. It is found that compared to LIBs, SIBs exhibit a higher reversible sodium (Na) storage capacity and superior cyclability. For sodiation, the volume change due to ion intercalation is smaller than that in lithiation. Also, sodiated WS 2 maintains its layered structure after the intercalation process, and the reduced metal nanoparticles after conversion in sodiation are well‐dispersed and aligned forming a pattern similar to the layered structure. Overall, this work shows a direct interconnection between the reaction dynamics of lithiated/sodiated WS 2 nanoflakes and their electrochemical performance, which sheds light on the rational optimization and development of advanced WS 2 ‐based electrodes.