The present work includes fabrication of a binary and ternary and composites of reduced graphene oxide (RGO), Polyaniline (Pani), and cobalt Prussian blue analog (Co-PA) for high performance supercapacitor. The materials were characterized using XRD, SEM, FT-IR, and BET techniques. The results confirm the formation of the desired nanocomposites. The electrochemical properties were evaluated in three electrode configuration using CV, CCD and EIS methods. The ternary composite of RGO@Pani@Co-PA showed better electrochemical properties than that obtained from the binary composites as well as their constituent components. The ternary-based sample had a specific capacitance of 490 Fg-1 at a current density of 1 A g-1 and a minimal capacitance loss of 93.9% after 3000 electric cycles. The ternary composites' remarkable electrochemical performance has been attributed to their well-thought-out, distinctive architecture, which offers a substantial surface area and promotes synergistic effects among the other ingredients. The ternary RGO@Pani@Co-PA composite was used as the anode electrode (positive) and activated carbon as the cathode (negative) materials in the assembly of the asymmetric supercapacitor (ASC) device. Over a wide potential window of 2 V, the fabricated ASC had a remarkable specific energy of 58.9 Wh kg-1 at a specific power of 9210 W kg-1 and 88.5% device capacitance stability after 5000 cycles of charge/discharge.