SnO2 Based Materials and Their Energy Storage Studies

We attempted to prepare SnO2 based oxide materials by molten salt method (MSM) using KCl at 850 and 1050 °C and 0.5 M KCl/0.5 M NaCl at 650 °C for 3 h in air. The compounds were characterized by Rietveld refined X-ray diffraction (XRD), X-ray photo electron spectroscopy (XPS), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) surface area methods. XRD studies show tetragonal SnO2 type structure. Compounds exhibited surface areas ranging from 0.78 to 5.68 m2 g–1. The electrochemical (anodic) behavior of samples prepared at 850 and 650 °C were examined by galvanostatic cycling (GC) and cyclic voltammetry (CV) vs Li-metal in the voltage range 0.005–1.0 V or 0.005–3.0 V vs Li. All compounds display the main cathodic peak at ∼0.25 V and anodic peak at ∼0.5 V based on the CV studies, which are characteristic cathodic and anodic peaks of SnO2. Anodic properties showed reversible capacity values in the range 631–679 mAhg–1 in the voltage range, 0.005–1.0 V vs Li. Tin oxides made from Co-sulfate and SnCl2 generally displayed a high storage capacity with good capacity retention. When we cycled to higher cutoff voltage (0.005–3.0 V), capacity fading was noted in all compounds due to the huge volume variation conversion reaction of respective Sn-oxides.