Electrochemical investigation on nickel-doped spinel magnesium ferrite nanoparticles for supercapacitor applications

Due to their extensive cycle life, significant power storage capacity, and quick recharge ability, electrochemical (EC) capacitors, namely supercapacitors (SCs), have attracted great interest from the scientific community. Recent research has shown transition metal oxides as the best material for the considerable performance of flexible SCs. X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) mapping, electron spin resonance (ESR) and Brunauer-Emmett-Teller (BET) studies were used to methodically characterize the synthesized Ni-doped MgFe2O4 nanoparticles. The typical size range of the nanoparticles is 8–11 nm. In 1 M KOH solution, the produced Ni0.35Mg0.65Fe2O4 (code as: NM3) electrode has been used as a pseudocapacitor, revealing an extraordinary specific capacitance of 119.04 F/g at a current density (CD) of 1.1 A/g compared to Ni0.15Mg0.85Fe2O4 (code as: NM1) and Ni0.25Mg0.75Fe2O4 (code as: NM2) electrodes. The electrochemical impedance spectra (EIS) were used to determine the electrode's EC properties. These findings indicate the potential use fullness of Ni-doped MgFe2O4 nanoparticles for SCs applications.