Polyaniline composites incorporating transition metals are still an burgeoning interest as a supercapacitive material due to the formation of metal-PANI hetero junctions. Herein we demonstrate a facile chemical synthesis of ternary doped supercapacitive polyaniline using transition metal as a codopant with an inorganic acid dopant utilizing the oxidant ferric chloride, which itself acts as a dopant. More interestingly the rational combination of external binary dopants can successfully modify PANI morphology. The as synthesized transition metals incorporated PANI (0.7 M Cu2+ + 1 M HCl) with a flake like morphology outperform as an energy storage material due to its high surface to volume ratio. Thus the synergistic effect of transitions metals (Cu & Fe) with HCl contribute towards the enhanced electrochemical performance of ternary doped PANI. The frequency dependent dielectric properties, ac conductivity and electrochemical characterizations using cyclic voltammetry and Electrochemical Impedance Spectroscopy of ternary doped PANI has been systematically studied. The ternary doped polyaniline demonstrated a high specific capacitance of 880 F/g and good cyclic stability in 0.1 M H2SO4 electrolyte.