Lithium-storage and cycleability of nano-CdSnO3 as an anode material for lithium-ion batteries

Nano-CdSnO3 is prepared by thermal decomposition of the precursor, CdSn(OH)(6) at 600 degrees C for 6 h in air. The material is characterized physically by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM) and selected-area electron diffraction (SAED) techniques. Nano-CdSnO3 exhibits a reversible and stable capacity of 475(+/- 5) mAh g(-1) (similar to 5 mol of cycleable Li per mole of CdSnO3) for at least 40 cycles between 0.005 and 1.0 V at a current rate of 0.13 C. Extensive capacity fading is found when cycling in the range 0.005-1.3 V. Cyclic voltammetry studies complement galvanostatic cycling data and reveal average discharge and charge potentials of 0.2 and 0.4 V, respectively. The proposed reaction mechanism is supported by ex situ XRD, TEM and SAED studies. The electrochemical impedance spectra taken during 1st and 10th cycle are fitted with an equivalent circuit to evaluate impedance parameters and the apparent chemical diffusion coefficient (DLi+) of Li. The bulk impedance, R-b, dominates at low voltages (<= 0.25 V), whereas the combined surface film and charge-transfer impedance (R(sf+ct)) and the Warburg impedance dominate at higher voltages, >= 0.25 V. The DLi+ is in the range of (0.5-0.9) x 10(-13) cm(2) s(-1) at V=0.5-1.0 V during the 10th cycle. (C) 2009 Elsevier B.V. All rights reserved.