title: One-Pot Fabrication of Hierarchical Nanosheet-Based TiO2 -Carbon Hollow Microspheres for Anode Materials of High-Rate Lithium-Ion Batteries.
abstract: Hierarchical and hollow nanostructures have recently attracted considerable attention because of their fantastic architectures and tunable property for facile lithium ion insertion and good cycling stability. In this study, a one-pot and unusual carving protocol is demonstrated for engineering hollow structures with a porous shell. Hierarchical TiO2 hollow spheres with nanosheet-assembled shells (TiO2 NHS) were synthesized by the sequestration between the titanium source and 2,2'-bipyridine-5,5'-dicarboxylic acid, and kinetically controlled etching in trifluoroacetic acid medium. In addition, annealing such porous nanostructures presents the advantage of imparting carbon-doped functional performance to its counterpart under different atmospheres. Such highly porous structures endow very large specifics surface area of 404 m(2)  g(-1) and 336 m(2)  g(-1) for the as-prepared and calcination under nitrogen gas. C/TiO2 NHS has high capacity of 204 mA h g(-1) at 1 C and a reversible capacity of 105 mA h g(-1) at a high rate of 20 C, and exhibits good cycling stability and superior rate capability as an anode material for lithium-ion batteries.
authors.affiliation: School of Materials and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian district, 100083, P.R. China.
authors.forename: Zhaokui
authors.initials: Z
authors.lastname: Jin
authors.affiliation: School of Materials and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian district, 100083, P.R. China.
authors.forename: Mu
authors.initials: M
authors.lastname: Yang
authors.affiliation: School of Materials and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian district, 100083, P.R. China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Materials and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian district, 100083, P.R. China. gaojiangniaoyi@163.com.
authors.forename: Hongyi
authors.initials: H
authors.lastname: Gao
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA, 90095, USA.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Lu
authors.affiliation: School of Materials and Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian district, 100083, P.R. China. gewang@126.com.
authors.forename: Ge
authors.initials: G
authors.lastname: Wang
keywords: doping; electrochemistry; lithium; nanostructures; titanium