Nano-ZnCo2O4 material preparation by molten salt method and its electrochemical properties for lithium batteries

Abstract

We synthesized nano-ZnCo2O4 using molten salt method at low temperature 280C for 30 min or 3h in air, at a heating and cooling rate of 3Cmin and quenching. Reported are the effects of Co-sulphate, hydroxide and Zn-sulphate salt combinations, and heating, cooling rate on morphology and crystal structure of the ZnCo2O4. ZnCo2O 4-I to IV phases were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Density and Brunauer-Emmett-Teller (BET) surface area methods. All samples (ZnCo2O4-I to III) showed single phase materials with a lattice parameter values of ∼8.102-8.126 and surface area are in the range of 5 to 32 m2+ g-1. Electrochemical properties were evaluated via cyclic voltammetry (CV) and galvanostatic cycling studies. CV studies showed a minor differences in the peak potentials depending on preparation method, and all compounds exhibits a main anodic peaks to occur at ∼1.65 V and ∼2.1 V and cathodic peaks at ∼0.95V, ∼1.25 V. Nano-ZnCo2O4-II prepared using Zn-sulphate and Co-hydroxide source showed a high and stable capacity of ∼974 mAh g-1 at the end of 40th cycle, at a current rate of 60 mA g-1 in the voltage range, 0.005V-3.0 V. Heat treated electrode of ZnCo2O4- III showed improved cycling stability up to 30 cycles. © 2011 The Electrochemical Society.