Herein, we report the fabrication and characterization of hybrid electrode material for supercapacitor applications. CaCO3 nanoparticles (Nps) are used as intercalator to avoid the restacking behavior of reduced graphene oxide (rGO) nanosheets. CaCO3 Nps and rGO sheets are fabricated employing precipitation technique and microwave irradiation method, respectively. The intercalation process is performed by magnetic stirring followed by ultra-sonication technique. As prepared CaCO3 Nps, rGO and rGO intercalated with 2.5 wt.% and 5 wt.% CaCO3 Nps are characterized using X-ray diffraction analysis, Fourier transform infrared spectroscopy and field emission scanning electron microscopy to evaluate the crystalline characteristics, molecular vibrations, and morphology, respectively. The prepared electrode materials are coated separately on the glassy carbon electrode and their electrochemical performance displayed remarkable capacitance values for rGO nanosheets intercalated with 2.5 wt.% and 5 wt.% CaCO3 Nps. From the obtained results, it is clear that the specific capacitance of 2.5 wt.% CaCO3 intercalated rGO displays higher specific capacitance of 84.5 Fig at 5 mV/s with high retention stability. The mechanism behind the improvement in the electrochemical behavior is due to the increase in active surface area which is explained via Brunauer-Emmett-Teller analysis and energy-dispersive X-ray spectroscopic analysis. (C) 2019 Elsevier Inc. All rights reserved.