|Abstract||Energy storage devices including supercapacitor are among the rapidly growing field of alternatives for rechargeable batteries due to its high energy density and long life cyclability performance. Electrospinning is a versatile process that produces polymer fibers. The diameter of these fibers ranges from micrometers to few nanometers. In this work, we aimed to synthesize Carbon nanofibers (CNF) from these polymer fibers by employing annealing (high temperature heat treatment). The fibers were doped with nitrogen (N) and/or sulfur (S) source during electrospun fibers fabrication. Later, the N and/or S doped CNF were loaded with mixed metal oxide e.g. Ni, Sn, and Ru by microwave technique. We characterized and investigated these materials and measured their performance for supercapacitor applications. Metal loaded 1 wt. % Thiourea doped sample electrodes showed a high specific capacitance value of 207.29 F.g-1 at scan rate of 10 mVs-1. This was ascribed to improved electrical conductivity and ion permittivity of carbon materials due to the presence of graphitic-nitrogen on carbon ring structure and nature of catalyst used. Hence, the synthesized materials represents as suitable electrode materials for high-performance supercapacitors.