Local structure of vanadium in doped LiFePO4.
LiFePO(4) composites with 5 at.% vanadium doping are prepared by solid state reactions. X-ray absorption fine-structure spectroscopy is used as a novel technique to identify vanadium sites. Both experimental analyses and theoretical simulations show that vanadium does not enter into the LiFePO(4) crystal lattice. When the vanadium concentration is lower then 1 at.%, the dopant remains insoluble. Thus, a single-phase vanadium-doped LiFePO(4) cannot be formed and the improved electrochemical properties of vanadium-doped LiFePO(4) previously reported cannot be associated with crystal structure changes of the LiFePO(4) via vanadium doping.
Zhao
Ting
T
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Xu
Wei
W
Ye
Qing
Q
Cheng
Jie
J
Zhao
Haifeng
H
Wu
Ziyu
Z
Xia
Dingguo
D
Chu
Wangsheng
W