Materials based on phosphate have been suggested as suitable electrode components for energy storage devices and also indicated that the phosphate framework can help to keep active sites stable. The physical and chemical properties of Fe-based phosphates make them promising cathode compounds for energy storage systems. In this work, the additive carbonous material as a bamboo charcoal (BCC) which was prepared and activated using the pyrolysis process. The irradiation of DC glow discharge plasma improved the surface attributes such as wettability, adhesion, and conductivity. Here, the hydrothermal technique was used to synthesize FePO4 nano particles. The dielectric behaviour was analysed at room temperature for pure FePO4 and composite of FePO4/Plasma treated BCC. The GCD behaviour of pure FePO4 and composite of FePO4/Plasma treated BCC was analysed with aqueous electrolyte of 2M KOH at different current densities. In perspective, the dielectric constant and specific capacitance of the FePO4/plasma treated BCC material seems to be very strong.