writer：Yanwei Li, Jinhuan Yao, Evan Uchaker, Ming Zhang, Jianjun Tian, Xiaoyan Liu, and Guozhong Cao*
keywords：V2O5, Thin film, Lithium ion storage performance
source：期刊
specific source：http://pubs.acs.org/doi/abs/10.1021/jp406927m
Issue time：2013年
Homogeneous
Sn-doped V₂O₅ sol was prepared by sol-gel method with H₂O₂,
V₂O₅, and  SnCl₄?5H₂O
as precursors and the films were fabricated by drop-casting, drying at ambient,
and then annealing at 450 °C
in air for 2 hours. X-ray photoelectron spectroscopy (XPS) reveals that the
Sn-doped V₂O₅ film contains 10% V⁴⁺, likely compensates
with the
accommodation of Sn⁴⁺ ions. Electrochemical and lithium-ion intercalation
properties of both the pure and Sn-doped V₂O₅ films are
systematically studied by means of cyclic voltammetry (CV), electrochemical
impedance spectroscopy (EIS), and chronopotentiometry (CP) tests. The Sn-doped V₂O₅
film shows much enhanced lithium-ion storage capacity, faster kinetics, and improved cyclic
stability in comparison with pure V₂O₅ film. For example,
after 50 cycles, the specific capacity of the Sn-doped V₂O₅
film retains 334 mAh g^?1 with a current density of 500 mA g^?1,
much higher than 157 mAh g^?1 of the pure V₂O₅
film. Sn-doping is found to reduce the electrochemical reaction resistance,
increase the electrochemical reaction reversibility, and enhance the
lithium-ion diffusivity. The possible explanation for such significant
enhancement in lithium-ion intercalation capacity and cyclic stability of the
Sn-doped V₂O₅ film is discussed.