Ag3O4 grafted NiO nanosheets for high performance supercapacitors

Ag3O4 grafted NiO nanosheets were successfully synthesized via hydrothermal route. The morphological and structural analysis was performed using scanning transmission electron microscopy (STEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies. The grafting of Ag3O4 on NiO nanosheets enhanced the conductivity of the nanosheets and resulted in a maximum specific capacitance of 1504 F g(-1) for 5 wt% of Ag on NiO (AGN2) at a scan rate of 3 mV s(-1). The porous nature of AGN2 provides larger paths for ions, which significantly increases the intercalation of ions and utilization rate of electrode materials. Galvanostatic charge discharge (GCD) analysis reveals a specific capacitance of 1524 F g(-1) for AGN2 at a current density of 1 A g(-1) with excellent cyclic stability (12% loss after 1500 cycles). An asymmetric supercapacitor device (AGN2//RGO) achieved a specific capacitance of 274 F g(-1) with an energy density of 37 Wh kg(-1) and the power density of 499 W kg(-1) at a discharge current of 0.2 A g(-1).