Molten salt synthesis and energy storage studies on CuCo2O4 and CuO·Co3O4

Abstract

CuCo₂O₄ and CuO·Co₃O₄ compounds were prepared by a one-pot simple molten salt method (MSM) at 280 °C to 750 °C. Changes in morphology, crystal structure and electrochemical properties of CuCo₂O₄ as a function of preparation temperatures were investigated using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Brunauer–Emmett–Teller absorption isotherm. XRD patterns of the sample prepared at 280 °C show a crystalline cubic structure with a lattice parameter value of a = 8.131 Å and a surface area value of 9.8 m² g⁻¹. The sample prepared at temperatures >510 °C shows the presence of CuO·Co₃O₄ phases. Energy storage properties are evaluated using cyclic voltammetry (CV) and galvanostatic cycling studies. CV studies show a main anodic peak at ∼2.1 V and cathodic peak at ∼1.2 V. At a current rate of 60 mA g⁻¹ and in the voltage range of 0.005–3.0 V vs. Li, CuCo₂O₄ composite prepared at 510 °C shows a high and stable capacity of ∼680 (quenched) and 740 (slow cooling) mAh g⁻¹ at the end of the 40th cycle.