Preparation of manganese vanadate cathode material for aqueous rechargeable zinc ION battery

Abstract

Aqueous rechargeable zinc ion battery(ZIB) is one of the promising alternatives to the lithium-ion battery owing to its high safety and low cost. However, suitable cathode material is still a major issue for their development. Here, we report a cathode material of manganese vanadate consisting a unique cauliflower morphology synthesized by using ammonium metavanadate and manganese acetate as precursor. One-step hydrothermal method is used to synthesize manganese vanadate. The material is characterized by x-ray crystallography (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) analysis. The synthesized product has cauliflower-like morphology with MnV2O6 structure that has monoclinic phase and is polycrystalline in nature. The d-spacing of the crystal planes are calculated which are suitable for the insertion/extraction of zinc ions from the cathode materials. The electrochemical performance is evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) using a two-electrode split-type coin cell under various scan rates. The specific capacity obtained 208 mAhg-1 using zinc sulphate electrolyte at 0.1 Ag-1 current density. The cycle stability was increased by the use of manganese sulfate additives up to 348 mAhg-1 at 0.1 A g-1 current density. These results clearly demonstrate that MnV2O6could be one of future cathode material for aqueous ZIBs.