Please use this identifier to cite or link to this item:
Title: Metal oxyfluorides TiOF2 and NbO2F as anodes for Li-ion batteries
Authors: Reddy, M.V. 
Madhavi, S.
Subba Rao, G.V. 
Chowdari, B.V.R. 
Keywords: Anodes
Coulombic efficiency
Discharge-charge cycling
Li-ion batteries
Metal oxyfluorides
Issue Date: 22-Nov-2006
Citation: Reddy, M.V., Madhavi, S., Subba Rao, G.V., Chowdari, B.V.R. (2006-11-22). Metal oxyfluorides TiOF2 and NbO2F as anodes for Li-ion batteries. Journal of Power Sources 162 (2 SPEC. ISS.) : 1312-1321. ScholarBank@NUS Repository.
Abstract: Lithium insertion and extraction in to/from the oxyfluorides TiOF2 and NbO2F is investigated by galvanostatic cycling, cyclic voltammetry and impedance spectroscopy in cells using Li-metal as a counter electrode at ambient temperature. The host compounds are prepared by low-temperature reaction and characterized by powder X-ray diffraction (XRD), Rietveld refinement and Brunauer, Emmett and Teller (BET) surface area. Crystal structure destruction occurs during the first-discharge reaction with Li at voltages below 0.8-0.9 V for LixTiOF2 as shown by ex situ XRD and at ≤1.4 V for LixNbO2F to form amorphous composites, 'LixTi/NbOy-LiF'. Galvanostatic discharge-charge cycling of 'LixTiOy' in the range 0.005-3.0 V at a current density of 65 mA g-1 gives a capacity of 400 (±5) mAh g-1 during 5-100 cycles with no noticeable capacity fading. This value corresponds to 1.52 mol of recycleable Li/Ti. The coulombic efficiency (η) is >98%. Results on 'LixNbOy' show good reversibility of the electrode and a η >98% is achieved only after 10 cycles (range 0.005-3.0 V and at 30 mA g-1) and a capacity of 180 (±5) mAh g-1 (0.97 mol of Li/Nb) was stable up to 40 cycles. In both 'LixTiOy' and 'LixNbOy', the average discharge and charge voltages are 1.2-1.4 and 1.7-1.8 V, respectively. The impedance spectral data measured during the first cycle and after selected numbers of cycles are fitted to an equivalent circuit and the roles played by the relevant parameters as a function of cycle number are discussed. © 2006 Elsevier B.V. All rights reserved.
Source Title: Journal of Power Sources
ISSN: 03787753
DOI: 10.1016/j.jpowsour.2006.08.020
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Nov 14, 2019


checked on Nov 6, 2019

Page view(s)

checked on Nov 9, 2019

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.