Unveiling a binary metal selenide composite of CuSe polyhedrons/CoSe2 nanorods decorated graphene oxide as an active electrode material for high-performance hybrid supercapacitors

Abstract With the unceasing upsurge in the evolution of electric vehicles flea market, supercapacitors (SCs) must be able to function under severe ecological situations. Although SCs are at the frontline in various technologies, their poor conductivity and energy density needs to be improved for commercial applicability. In this regard, various highly active electrode materials with compatible nanostructures and tunable chemical properties have been prepared and employed. In this work, a new category of CoSe2 nanorod-CuSe polyhedron- decorated graphene oxide (GO) (CCS@GO) hybrid electrode material was designed and studied for its application in high-performance hybrid asymmetric SCs (HASCs) for the first time. Owing to their specific architecture, high mesoporosity, and rapid transportation of electrons/ions, an asymmetric SC device with a CCS@GO//activated-carbon (AC) electrode exhibited excellent electrochemical properties that endowed it with a high specific capacitance of 192.8 Fg−1 at 1 Ag−1 and extensive energy and power densities of 54.6 Whkg−1 and 700 Wkg−1 respectively. Furthermore, the long-term durability over 10,000 cycles with capacitance retention of 82.5% suggests that the CCS@GO//AC HASC has immense potential for future-generation electronic devices and hybrid electric vehicles.