▎ 摘　　要

Manganese dioxide/reduced graphene oxide/indium tin oxide (MRI) and polypyrrole/reduced graphene oxide/indium tin oxide (PRI) electrodes were prepared via the chronopotentiometric-deposition of either manganese oxide or polypyrrole, respectively, onto a RGO/ITO film at a constant current density. Solid-state asymmetric supercapacitors (ASC) were assembled using MRI as the positive electrode and PRI as the negative electrode in a PVA/LiCl gel electrolyte. These devices displayed a power density of 7.4 kW/kg (for an energy density of 13 Wh/kg), an energy density of 16 Wh/kg (for a power density of 0.3 kW/kg), and a capacitance retention of 75% over 2000 cycles. The MRI//PRI ASC exhibited a much improved capacitive performance compared to the symmetric PRI//PRI (3 Wh/kg at 0.47 kW/kg) and MRI//MRI (9 Wh/kg at 0.12 kW/kg) supercapacitors. The superior capacitive performance of the MRI//PRI ASC was ascribed the improved conductivities and mechanical stabilities of MRI and PRI electrodes, obtained by preparing the polypyrrole and manganese oxide films on a graphene-coated electrode. (C) 2014 Elsevier B.V. All rights reserved.