▎ 摘　　要

Asymmetric Supercapacitor (ASC) was effectively fabricated using CR 2032-coin cell based on the positive electrode of the hybrid Ag@rGO nanocomposite and the negative electrode of reduced Graphene Oxide (rGO) material with polyvinyl alcohol (PVA)/6 M KOH electrolyte. The Ag@rGO nanocomposite was prepared through a seed-mediated growing process by a 10 wt% of Ag nanomaterials deposits in suspension rGO 90 wt% which presented a specific capacitance value of 65.9 F g(-1) at current density of 0.5 A g(-1). Moreover, the rGO electrode with a 5 mg/mL concentration was synthesized by the modified Hummers' method and revealed a high specific capacitance value of 317.3 F g(-1) at current density of 0.5 A g(-1). Interestingly, the ASC assembly of Ag@rGO//rGO hybrid energy-storage device provided a wide voltage window of 0.0-1.4 V and showed a specific capacitance (C-SC) value of 44.17 F g(-1) at current density of 3 A g(-1). This hybrid energy-storage device indicated specific energy density (Esp ) of 11.09 W h kg(-1) and specific power density (E-SP) of 2.67 kW kg(-1), respectively. It also showed a good cycle stability of 81.5%. The capacitance retention finished at 500 cycles. (C) 2020 Elsevier B.V. All rights reserved.