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Surface Amorphization of Vanadium Dioxide (B) for K‐Ion Battery
Author(s) -
Li Youpeng,
Zhang Qiaobao,
Yuan Yifei,
Liu Haodong,
Yang Chenghao,
Lin Zhang,
Lu Jun
Publication year - 2020
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202000717
Subject(s) - materials science , amorphous solid , electrolyte , anode , chemical engineering , vanadium , nanorod , ion , battery (electricity) , density functional theory , ionic bonding , chemical physics , nanotechnology , electrode , crystallography , chemistry , thermodynamics , power (physics) , physics , computational chemistry , engineering , metallurgy , quantum mechanics
Given the merits of low cost, fast ionic transport in electrolyte, and high operating voltage, potassium ion batteries (PIBs) are promising alternatives to lithium‐ion batteries. However, developing suitable electrode materials that can reversibly accommodate large potassium ions is a great challenge. Here, guided by density functional theory (DFT) calculations, it is demonstrated that the strategy of interfacial engineering via surface amorphization of VO 2 (B) nanorods (SA‐VO 2 ), which results in the formation of a crystalline core/amorphous shell heterostructure, enables superior K + storage performance in terms of large capacity, outstanding rate capability, and long cycle stability working as an anode for PIBs. DFT calculations reveal that the created crystalline/amorphous heterointerface in SA‐VO 2 can substantially lower the surface energy, narrow the band gap, and reduce the K + diffusion barrier of VO 2 (B). These conditions enable enhanced K + storage capacity and rapid K + /electron transfer, which result in large capacity and outstanding rate capability. Using in situ X‐ray diffraction and in situ transmission electron microscopy complemented by ex situ microscopic and spectroscopic techniques, it is unveiled that the superior cycling stability originates from the excellent phase reversibility with negligible strain response and robust mechanical behavior of SA‐VO 2 upon (de)potassiation.