Electrode material with exceptional durability, energy density, and rate performance has been of great interest in next-generation advanced supercapacitor applications in recent years. In this paper, we portray the facile synthesis of carbon nanofibers (CNFs) and cadmium sulfide (CdS) for a supercapacitor that obtained the capacitances of 335 F/g and 210 F/g when tested in an aqueous conducting medium in a three-electrode mode over a wide potential range between 0.0 to 0.8 V. The performance of pure electrode materials is not satisfactory; therefore, a composite of CdS/CNFs was further fabricated that exhibits enhanced energy storage performance in terms of the capacitance of 510 F/g, and a minor charge transfer resistance compared with pure counterparts. The fascinating performance was turned to develop an asymmetric supercapacitor (CdS/CNFs||AC), which realizes a high voltage of up to 2.0 V. It is believed that optimization of voltage put significant enhancement in energy and power delivery. Interestingly, a high power of 9000 W/kg was accomplished with maximum energy of 31.94 Wh/kg at high and low discharge current rates. Additionally, only a 15.3% capacity fade was attained and 85.7% retention at a high current rate of 20 A/g for 7500 cycles. Our strategy is synthesizing other metal oxide-based composite electrodes for future energy storage domains. [ABSTRACT FROM AUTHOR]