This study discusses a simple and feasible method that involves in-situ polymerization of aniline in the presence of zinc acetate dihydrate [Zn(CH3COO)2·2H2O] and graphene nanoplatelets (GNP) for the preparation of high performance electrode material (PZG composite) for supercapacitor application. In the presence of metal salt [Zn(CH3COO)2·2H2O], the capacitance value is changed and increased enormously compared to the capacitance value of PANI/GNP (PG) composite. Thus, the proposed method gives specific capacitance value for the PZG composite is ∼688F/g at a 10mV/s scan rate which is very high compared to the specific capacitance value (∼340F/g) of PG composite at the same scan rate. In the PZG composite, zinc acetate and GNP are successfully coated by PANI, which provides more active sites for nucleation and electron transfer path. In addition, the inter- and intra-molecular interactions among them facilitate the electron transfer path which plays an important role to enhance the capacitance value of the composite. Moreover, the prepared composite is electrically conducting in nature and shows electrical conductivity in the order of ≈4.67×10−2 Scm−1. In addition, PZG composite shows semi-conducting behavior. Field Emission Scanning Electron Microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) have been studied for the morphological analysis of the PZG composite.