title: Niobium(V) oxynitride: synthesis, characterization, and feasibility as anode material for rechargeable lithium-ion batteries.
abstract: The decomposition reaction of niobium(V) oxytrichloride ammoniate to the oxynitride of niobium in the 5+ oxidation state was developed in a methodological way. By combining elemental analysis, Rietveld refinements of X-ray and neutron diffraction data, SEM and TEM, the sample compound was identified as approximately 5 nm-diameter particles of NbO(1.3(1))N(0.7(1)) crystallizing with baddeleyite-type structure. The thermal stability of this compound was studied in detail by thermogravimetric/differential thermal analysis and temperature-dependent X-ray diffraction. Moreover, the electrochemical uptake and release by the galvanostatic cycling method of pure and carbon-coated NbO(1.3(1))N(0.7(1)) versus lithium was investigated as an example of an Li-free transition-metal oxynitride. The results showed that reversible capacities as high as 250 and 80 A h  kg(-1) can be reached in voltage ranges of 0.05-3 and 1-3 V, respectively. Furthermore, a plausible mechanism for the charge-discharge reaction is proposed.
authors.affiliation: Laboratory of Inorganic Chemistry, ETH Zürich, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland. xj.wang@inorg.chem.ethz.ch
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Wang
authors.forename: Frank
authors.initials: F
authors.lastname: Krumeich
authors.forename: Michael
authors.initials: M
authors.lastname: Wörle
authors.forename: Reinhard
authors.initials: R
authors.lastname: Nesper
authors.forename: Laurent
authors.initials: L
authors.lastname: Jantsky
authors.forename: Helmer
authors.initials: H
authors.lastname: Fjellvåg
mesh_terms: D011211:Electric Power Supplies; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D009556:Niobium / Q000737:chemistry*
chemical_list: D009556:Niobium; D008094:Lithium