title: N-doped graphene-VO2(B) nanosheet-built 3D flower hybrid for lithium ion battery.
abstract: Recently, we have shown that the graphene-VO2(B) nanotube hybrid is a promising lithium ion battery cathode material (Nethravathi et al. Carbon, 2012, 50, 4839-4846). Though the observed capacity of this material was quite satisfactory, the rate capability was not. To improve the rate capability we wanted to prepare a graphene-VO2(B) hybrid in which the VO2(B) would be built on 2D nanosheets that would enable better electrode-electrolyte contact. Such a material, a N-doped graphene-VO2(B) nanosheet-built 3D flower hybrid, is fabricated by a single-step hydrothermal reaction within a mixture of ammonium vanadate and colloidal dispersion of graphite oxide. The 3D VO2(B) flowers which are uniformly distributed on N-doped graphene are composed of ultrathin 2D nanosheets. When used in lithium ion batteries, this material exhibits a large capacity, high rate capability, and excellent cycling stability. The enhanced performance results from its unique features: excellent electronic conductivity associated with the N-doped graphene, short transportation length for lithium ions related to ultrathin nanosheets, and improved charge transfer due to the anchoring of the VO2(B) flowers to N-doped graphene.
authors.affiliation: International Center for Materials, Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan. nethravathic@gmail.com
authors.forename: C
authors.initials: C
authors.lastname: Nethravathi
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Rajamathi
authors.forename: Michael
authors.initials: M
authors.lastname: Rajamathi
authors.forename: Ujjal K
authors.initials: UK
authors.lastname: Gautam
authors.forename: Xi
authors.initials: X
authors.lastname: Wang
authors.forename: Dmitri
authors.initials: D
authors.lastname: Golberg
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Bando