Electrochemical performance investigation of different shaped transition metal diselenide materials based symmetric supercapacitor with theoretical investigation

Transition metal diselenide-based electrodes for hybrid symmetric supercapacitors appear as trending materials. Thereby in this paper, we report the preparation of different-shaped transition metal diselenides using a single-step hydrothermal route. The impact of the different morphology of the prepared transition metal diselenide material has been studied on their electrochemical performance. The nanoflower-shaped MoSe2 material was observed to deliver the highest electrochemical result than nanoneedles and nanospheres shape of CoSe2 and NiSe2 material respectively. The highest specific capacitance delivered by the MoSe2 material-based symmetric supercapacitor was 154 F g−1 at 10 mV s−1. It also exhibits a maximum energy density of 17 Wh kg−1 with 1267 W kg−1 power density. Further, the MoSe2-based symmetric supercapacitor has been utilized to burn different colors of light-emitting diodes along with a panel of 26 LEDs of red color. To make the working of the symmetric supercapacitor (MoSe2-based) easier to understand for the readers we have proposed a mechanism of charge storage associated with it. Additionally, the experimental finding has been supported by investigating the structural and electronic properties of MoSe2, CoSe2, and NiSe2 via density functional theory calculation.