Synthesis and characterization of M3V2O8 (M = Ni or Co) based nanostructures: a new family of high performance pseudocapacitive materials

Abstract

Binary metal oxides have recently attracted extensive attention from researchers in the energy storage field due to their multiple oxidation states and high energy density. In the present work, Ni₃V₂O₈, Co₃V₂O₈, and the Ni₃V₂O₈/Co₃V₂O₈ nanocomposite are designed and synthesized as a new class of high performance electrode material for supercapacitors. Ni₃V₂O₈ and Co₃V₂O₈ show a structure comprising nanoflakes and nanoparticles, respectively. The Ni₃V₂O₈/Co₃V₂O₈ nanocomposite is prepared by growing Co₃V₂O₈ nanoparticles on the surface of Ni₃V₂O₈ nanoflakes. The composite inherits the structural characteristics and combines the pseudocapacitive benefits of both Ni₃V₂O₈ and Co₃V₂O₈, showing higher specific capacitance than Co₃V₂O₈ and superior rate capability as well as better cycle stability to Ni₃V₂O₈. The dependence of pseudocapacitive properties of the Ni₃V₂O₈/Co₃V₂O₈ nanocomposite on the Ni/Co mass ratio is also investigated, indicating that the high specific capacitance of the composite is contributed by Ni₃V₂O₈, while its excellent rate capability and cycle stability can be attributed to the Co₃V₂O₈ component.