Electrochemical Behavior of MgO‐PPy‐AC Composite Material for Energy Storage Devices

ABSTRACT In the search for safer, more affordable, and environmentally friendly alternatives to Li‐ion batteries, scientists have turned their attention to multivalent ion battery systems, particularly magnesium‐ion (Mg‐ion) batteries. This study focuses on the synthesis and characterization of magnesium oxide (MgO) nanoparticles using a simple co‐precipitation method to explore their application in magnesium‐ion batteries. Characterization of the synthesized MgO nanoparticles was carried out using various techniques. X‐ray diffraction (XRD) analysis confirmed the crystalline nature and nanoscale structure of the samples, with an estimated crystallite size of approximately 46 nm. Fourier transform infrared spectroscopy (FTIR) identified the presence of Mg‐O stretching vibrations, whereas ultraviolet–visible‐near infrared (UV–vis–NIR) spectroscopy determined the optical band gap to be 5.07 eV. To enhance electrochemical performance, a composite material was fabricated by incorporating MgO nanoparticles with polypyrrole (PPy) and activated charcoal (AC). Cyclic voltammetry (CV) analysis revealed a quasi‐reversible redox process in the composite, with a peak specific capacitance of 713 F g −1 at a scan rate of 25 mV s −1 . Electrochemical impedance spectroscopy further demonstrated the dielectric behavior of MgO nanoparticles, reinforcing their potential in charge storage and ion transport. Overall, the findings of this research highlight the exceptional electrochemical properties of the MgO‐PPy‐AC composite, making it a promising electrode material for next‐generation energy storage devices, such as batteries and supercapacitors.