The electrode materials for supercapacitors based on biomass-produced Rice Husk Activated Carbon (RHAC) and RHAC+50% MgO nanocomposite are compared in this article. The crystallinity, structural morphology, and crystalline size of the particles were determined using microstructural and electrochemical characterization. Scanning Electron Microscope and X-Ray Diffraction techniques were used to determine the surface morphology and crystallinity of the materials. The XRD results reveal that RHAC which has broad peaks indicates amorphous nature whereas RHAC+50% MgO nanocomposite which has sharp peaks exhibits crystalline nature. The RHAC+50% MgO nanocomposite electrode exhibits a specific capacitance of 220.52 F/g however RHAC electrode exhibited only 162.91 F/g at a scan rate of 2mV/s by Cyclic Voltammetry in 1 M KOH electrolyte. After 2500 cycles of Galvanic charge-discharge, it was discovered that RHAC+50% MgO nanocomposite has capacitance retention of 76.71% and RHAC has capacitance retention of 80.49%.