Reduced graphene oxide/polypyrrole nanotube papers for flexible all-solid-state supercapacitors with excellent rate capability and high energy density

Pseudocapacitive materials are known to suffer from severe capacitance loss during charging/discharging cycling. Here we report flexible all-solid-state supercapacitors (ASSSCs) based on reduced graphene oxide (rG0)/polypyrrole nanotube (PPy NT) papers prepared by a facile vacuum filtration method. It is revealed that the incorporation of rGO nanosheets can improve the electrochemical stability of PPy NT paper electrodes for pseudocapacitors. The hybrid paper electrode shows a high areal specific capacitance of 807 mF/cm(2) at 1 mA/cm(2) and a large volumetric specific capacitance of 943 F/cm(3) at 0.1 A/cm(3). The assembled ASSSC possesses a maximum areal specific capacitance of 512 mF/cm(2) at 1 mA/cm(2) and a maximum volumetric specific capacitance of 59.9 F/cm(3) at 0.1 A/cm(3). Moreover, it also exhibits excellent rate capability (86.3% capacitance retention from 1 to 10 mA/cm(2)) and cycling stability, little capacitance deviation under different bending states, a small leakage current and a low self-discharge characteristic. The device can provide an areal energy density of 61.4 mu Wh/cm(2) at 10 mW/cm(2) and a volumetric energy density of 7.18 mWh/cm(3) at 1.17 W/cm(3), indicating this high-performance ASSSC is a promising candidate for flexible high-power supply devices. (C) 2015 Elsevier B.V. All rights reserved.