Controlled synthesis of 2H-WSe2@rGO nanocomposites: An efficient electrode material for high performance asymmetric supercapacitor device application

Abstract

In this article, 2H-WSe2 (WSe2) and 2H-WSe2@rGO (WSe2@rGO) nanocomposite are synthesized using one-step solvothermal method. The synthesized materials are characterized using different experimental techniques. The specific capacitance (SC) of WSe2@rGO electrode is calculated to be 1371 Fg−1 at 0.5 Ag−1 in 3 M KOH electrolyte. The value of SC of WSe2@rGO electrode is twice than that of the value of SC of WSe2 electrode. The WSe2@rGO electrode retains 88.0% of its initial SC after 3000 cycles. An asymmetric supercapacitor (WSe2@rGO//AC) device is fabricated by taking activated carbon (AC) and WSe2@rGO as negative and positive electrodes, respectively. The energy density of the fabricated device is calculated to be 51.5 Whkg−1 at the power density of 2133.3 Wkg−1. The WSe2@rGO//AC device retains 82.0% of its initial value of SC at 7 Ag−1 current density after 3000 cycles. The WSe2@rGO//AC device illuminates red, green, and blue light emitting diode (LEDs) for 20, 10, and 5 min, respectively after being charged for 30 s. Thus, the WSe2@rGO may be used as an effective electrode material for fabricating efficient and stable energy storage devices.