Hydrothermal assisted in situ growth of CoSe onto graphene nanosheets as a nanohybrid positive electrode for asymmetric supercapacitors

摘要: Cobalt selenide–graphene (CoSe–G) nanohybrid was successfully synthesised by a simple and facile one-pot hydrothermal method used as positive electrode for an asymmetric supercapacitor. The CoSe–G exhibits higher specific capacitance of 1037 F g−1 at 5 mV s−1 than CoSe. electrochemical impedance studies revealed that the graphene in not only reduced contact resistance but also significantly increases electrons transport. good performance is synergy between CoSe graphene. In addition, supercapacitor (ASC) fabricated using activated carbon negative electrode, respectively, electrospun PVdF membrane containing 6 M KOH separator well electrolyte. ASC delivered extended operating voltage window 1.6 V. It provides energy density 45.5 W h kg−1 power 1.1 kW retains 81% its initial even after 5000 cycles.