无定形固体
材料科学
氧化钒
钒
拉曼光谱
锂(药物)
X射线吸收光谱法
氧化物
吸收光谱法
分析化学(期刊)
结晶学
化学
光学
物理
内分泌学
冶金
医学
量子力学
色谱法
作者
Bei Wu,Shuwen Niu,Chao Wang,Geng Wu,Yida Zhang,Xiao Han,Peigen Liu,Yue Lin,Wensheng Yan,Gongming Wang,Xun Hong
出处
期刊:Small
[Wiley]
日期:2023-06-28
被引量:1
标识
DOI:10.1002/smll.202303360
摘要
Transition metal oxides with high theoretical capacities are promising anode materials for lithium-ion batteries (LIBs). However, the sluggish reaction kinetics remain a bottleneck for fast-charging applications due to its slow Li+ migration rate. Herein, a strategy is reported of significantly reducing the Li+ diffusion barrier of amorphous vanadium oxide by constructing a specific ratio of the VO local polyhedron configuration in amorphous nanosheets. The optimized amorphous vanadium oxide nanosheets with a ratio ≈1:4 for octahedron sites (Oh ) to pyramidal sites (C4v ) revealed by Raman spectroscopy and X-ray absorption spectroscopy (XAS) demonstrate the highest rate capability (356.7 mA h g-1 at 10.0 A g-1 ) and long-term cycling life (455.6 mA h g-1 at 2.0 A g-1 over 1200 cycles). Density functional theory (DFT)calculations further verify that the local structure (Oh :C4v = 1:4) intrinsically changes the degree of orbital hybridization between V and O atoms and contributes to a higher intensity of electron occupied states near the Fermi level, thus resulting in a low Li+ diffusion barrier for favorable Li+ transport kinetics. Moreover, the amorphous vanadium oxide nanosheets possess a reversible VO vibration mode and volume expansion rate close to 0.3%, as determined through in situ Raman and in situ transmission electron microscopy.
科研通智能强力驱动
Strongly Powered by AbleSci AI