Ni/NiFe₂O₄@carbon nanocomposite involving synergistic effect for high-energy density and high-power density supercapattery

In this work, a facile one step solution combustion method was applied to generate Nickel-nickel ferrite@Carbon nanocomposite using glycine as a fuel. The formation of metal ferrite@carbon phase was confirmed by x-ray diffraction, Raman and Fourier transformed infrared spectroscopy analyses. Field emission scanning electron microscope/energy dispersive x-ray analysis observations confirmed the presence of agglomerated spherical particles with uniform size distribution. The estimated pore size was in the range of 35-55 nm. High resolution transmission electron microscope analysis of the nickel-nickel ferrite@carbon nanocomposite revealed the presence of spherical nickel/ferrite grains in the size range of 13-19 nm within the carbon matrix. Ni/NiFe₂O₄@C was found to be electrochemically active in 1 M KOH delivering specific capacity of 1710 C g^-1 at a current density of 2 A g^-1. Supercapattery device were assembled using the Ni/NiFe₂O₄@C as positive electrode and reduced graphene-oxide (rGO) as negative electrode exhibited energy density of 62 Wh kg^-1 at a power density of 3440 W kg^-1 in the optimum potential window of 0-1.2 V, while the power density approached over 8000 W kg^-1 at the energy density of 22 Wh kg^-1. The practical applicability of the supercapattery was demonstrated by powering a commercial LED bulb.