Supercapacitors are extensively studied in the energy storage field because of their high power density and cycle stability compared to batteries. Conducting a thorough electrochemical analysis is essential for developing high-performance electrode materials. This chapter offers an in-depth examination of the electrochemical performance of reduced graphene oxide (rGO)-based electrodes using galvanostatic charge–discharge (GCD) testing to fully unlock the potential of rGO in supercapacitors. The findings indicate that rGO-based electrodes, thanks to their superior material properties, can achieve higher energy density and better stability. The combined effects of reduction time, current density, and nanocomposites on electrochemical performance are analyzed in detail, highlighting their significant potential to enhance the capacity and efficiency of energy storage systems.