title: Effects of Preinserted Na Ions on Li-Ion Electrochemical Intercalation Properties of V2O5.
abstract: Na-preinserted V2O5 samples of NaxV2O5 (x = 0.00, 0.005, 0.01, or 0.02) were synthesized through sol-gel and freeze-drying routes and subsequent calcination. X-ray diffraction (XRD) results showed that all of the synthesized materials have typical orthorhombic structures without impurity phases. The lattice parameters were refined via the Rietveld refinement method, and the results suggested that the lattice parameters of preinserted samples increased in comparison with pristine V2O5. X-ray photoelectron spectroscopy (XPS) measurements demonstrated that the V(4+) concentration in the Na-preinserted V2O5 samples gradually increased as amount of sodium increased. Results from both XRD and XPS strongly suggested that Na ions indeed enter the interlamination position in the V2O5 crystal to expand the channels for Li-ion migration. NaxV2O5 samples exhibited improved electrochemical properties compared with those of pristine V2O5. Among all of the samples, Na0.01V2O5 delivered the highest reversible specific capacity, best cycling stability, and excellent rate capability. The analysis and discussion on ion diffusion revealed that the preinserted Na ions benefited the mobility of Li ions to improve the rate capabilities of electrodes.
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.|College of Life and Environmental Science, Minzu University of China , Beijing 100081, China.
authors: Xinyuan
authors: X
authors: Li
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Chaofeng
authors: C
authors: Liu
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Changkun
authors: C
authors: Zhang
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Haoyu
authors: H
authors: Fu
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Xihui
authors: X
authors: Nan
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Wenda
authors: W
authors: Ma
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Zhuoyu
authors: Z
authors: Li
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.
authors: Kan
authors: K
authors: Wang
authors: College of Life and Environmental Science, Minzu University of China , Beijing 100081, China.
authors: Haibo
authors: H
authors: Wu
authors: Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, National Center for Nanoscience and Technology (NCNST) , Beijing 100083, China.|Department of Materials Science and Engineering, University of Washington , Seattle, Washington 98195, United States.
authors: Guozhong
authors: G
authors: Cao
keywords: Na preinsertion; V2O5; cathode; electrochemical intercalation; lithium-ion battery