The field of science has shown an abundance of interest in electrochemical capacitors, namely supercapacitors. They have a large power storage capacity and short recharging times due to their lengthy cycle life. In the present study, the Mg-doped nickel ferrite Ni1-xMgxFe2O4 (x=0.5) was prepared by the co-precipitation method. The samples were examined using different techniques for various annealing temperatures (400℃,600℃,700℃) for structural and morphological characterization. By using XRD, the structural details of the synthesized samples were elucidated. By using TG/DT analysis the optimum temperature of the samples, determining to be 700℃. As a result, additional analysis was done for the sample annealed at 700℃. SEM and HR-TEM were used to study the nanoparticle’s morphology which revealed well-defined nanostructures with an agglomerated spherical morphology. From the obtained vibrational bands, the FTIR spectra illustrate the occurrence of the spinel phase. The surface area of the nanoparticles was used to record the BET technique. The elemental composition and chemical states of constituent elements were identified through XPS analysis. The electrochemical properties of the nanoparticles were assessed by CV from which a higher capacitance reading of 412 Fg-1 at a low scan rate of 2mVs-1 has been reached confirming which will be suitable for supercapacitor applications.