Densely-packed graphene/conducting polymer nanoparticle papers for high-volumetric-performance flexible all-solid-state supercapacitors

Graphene-based all-solid-state supercapacitors (ASSSCs) are one of the most ideal candidates for highperformance flexible power sources. The achievement of high volumetric energy density is highly desired for practical application of this type of ASSSCs. Here, we present a facile method to boost volumetric performances of graphene-based flexible ASSSCs through incorporation of ultrafine polyaniline-poly(4-styrenesulfonate) (PANI-PSS) nanoparticles in reduced graphene oxide (rGO) papers. A compact structure is obtained via intimate contact and pi-pi interaction between PANI-PSS nanoparticles and rGO sheets. The hybrid paper electrode with the film thickness of 13.5 mu m, shows an extremely high volumetric specific capacitance of 272 F/cm(3) (0.37 A/cm(3) in a three-electrode cell). The assembled ASSSCs show a large volumetric specific capacitance of 217 F/cm(3) (0.37 A/cm(3) in a two-electrode cell), high volumetric energy and power density, excellent capacitance stability, small leakage current as well as low self-discharge characteristics, revealing the usefulness of this robust hybrid paper for high-performance flexible energy storage devices. (C) 2016 Elsevier B.V. All rights reserved.