title: In situ nitrogenated graphene-few-layer WS2 composites for fast and reversible Li+ storage.
abstract: Two-dimensional nanosheets can leverage on their open architecture to support facile insertion and removal of Li(+) as lithium-ion battery electrode materials. In this study, two two-dimensional nanosheets with complementary functions, namely nitrogen-doped graphene and few-layer WS2, were integrated via a facile surfactant-assisted synthesis under hydrothermal conditions. The layer structure and morphology of the composites were confirmed by X-ray diffraction, scanning electron microscopy and high-resolution transmission microscopy. The effects of surfactant amount on the WS2 layer number were investigated and the performance of the layered composites as high energy density lithium-ion battery anodes was evaluated. The composite formed with a surfactant : tungsten precursor ratio of 1 : 1 delivered the best cyclability (average of only 0.08% capacity fade per cycle for 100 cycles) and good rate performance (80% capacity retention with a 50-fold increase in current density from 100 mA g(-1) to 5000 mA g(-1)), and may find uses in power-oriented applications.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: Dongyun
authors.initials: D
authors.lastname: Chen
authors.forename: Ge
authors.initials: G
authors.lastname: Ji
authors.forename: Bo
authors.initials: B
authors.lastname: Ding
authors.forename: Yue
authors.initials: Y
authors.lastname: Ma
authors.forename: Baihua
authors.initials: B
authors.lastname: Qu
authors.forename: Weixiang
authors.initials: W
authors.lastname: Chen
authors.forename: Jim Yang
authors.initials: JY
authors.lastname: Lee
mesh_terms: D011211:Electric Power Supplies; D055664:Electrochemical Techniques; D006108:Graphite / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D010087:Oxides / Q000737:chemistry
chemical_list: D007477:Ions; D008670:Metals; D010087:Oxides; D006108:Graphite; D008094:Lithium