Facile one pot synthesis and Li-cycling properties of MnO sub(2)

For the first time, a molten salt method was attempted to prepare MnO sub(2) with three different precursors of Mn(CH sub(3)COO) sub(2), Mn(NO sub(3)) sub(2) and MnSO sub(4).H sub(2)O by using 0.375 M LiNO sub(3), 0.18 M NaNO sub(3) : 0.445 M KNO sub(3) as a molten salt heated at 380 degree C for the application of lithium batteries. The prepared compounds were characterized by various techniques such as, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), a surface area analyzer and scanning electron microscopy (SEM), respectively. XRD results revealed the cubic phase of lambda -MnO sub(2) and tetragonal phase of alpha -MnO sub(2) and the morphology of the compounds shows spherical particles as well as rod shaped nano-sized particles. The electrochemical performance of the compounds has been evaluated by, galvanostatic cycling (GC), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The Li-cycling results indicated that the performance of nano-rod shaped alpha -MnO sub(2) prepared by MnSO sub(4).H sub(2)O exhibits a stable and high reversible capacity of 845 mA h g super(-1) (87.5% capacity retention) at the end of the 50 super(th) cycle, cycled at a constant current density of 60 mA g super(-1), in the potential range of 0.005-3.0 V vs.Li. The MnO sub(2) compound prepared by using three different precursors shows a stable coulombic efficiency of 99% after a few cycles.