title: Exfoliated Graphene Oxide/MoO2 Composites as Anode Materials in Lithium-Ion Batteries: An Insight into Intercalation of Li and Conversion Mechanism of MoO2.
abstract: Exfoliated graphene oxide (EG)/MoO2 composites are synthesized by a simple solid-state graphenothermal reduction method. Graphene oxide (GO) is used as a reducing agent to reduce MoO3 and as a source for EG. The formation of different submicron sized morphologies such as spheres, rods, flowers, etc., of monoclinic MoO2 on EG surfaces is confirmed by complementary characterization techniques. As-synthesized EG/MoO2 composite with a higher weight percentage of EG performed excellently as an anode material in lithium-ion batteries. The galvanostatic cycling studies aided with postcycling cyclic voltammetry and galvanostatic intermittent titrations followed by ex situ structural studies clearly indicate that Li intercalation into MoO2 is transformed into conversion upon aging at low current densities while intercalation mechanism is preferably taking place at higher current rates. The intercalation mechanism is found to be promising for steady-state capacity throughout the cycling because of excess graphene and higher current density even in the operating voltage window of 0.005-3.0 V in which MoO2 undergoes conversion below 0.8 V.
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India.
authors.forename: Shaikshavali
authors.initials: S
authors.lastname: Petnikota
authors.affiliation: NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957, Singapore.
authors.forename: Keefe Wayne
authors.initials: KW
authors.lastname: Teo
authors.affiliation: NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957, Singapore.
authors.forename: Luo
authors.initials: L
authors.lastname: Chen
authors.affiliation: NUS High School of Mathematics and Science , 20 Clementi Avenue 1, Singapore 129957, Singapore.
authors.forename: Amos
authors.initials: A
authors.lastname: Sim
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India.
authors.forename: Sandeep Kumar
authors.initials: SK
authors.lastname: Marka
authors.forename: M V
authors.initials: MV
authors.lastname: Reddy
authors.affiliation: School of Engineering Sciences and Technology, University of Hyderabad , Gachibowli, Hyderabad 500046, India.
authors.forename: V V S S
authors.initials: VV
authors.lastname: Srikanth
authors.forename: S
authors.initials: S
authors.lastname: Adams
authors.forename: B V R
authors.initials: BV
authors.lastname: Chowdari
keywords: anode; composite; graphene oxide; graphenothermal reduction; lithium ion batteries; molybdenum oxide