Enhanced active sites possessing three-dimensional ternary nanocomposites of reduced graphene oxide/polyaniline/Vulcan carbon for high performance supercapacitors

Three-dimensional ternary nanocomposites of reduced graphene oxide/polyaniline/Vulcan carbon(rGO/PANI/VC) were prepared through a simple sonication method. The Vulcan carbons within rGO/polyaniline composites (rGO/PANI) act as spacer to enhance the active sites for electrochemical reaction, resulting in the improvement of capacitive performances. Extra ion-diffusion paths were also created accordingly, resulting in the improvement of rate performance. Additionally, the cycle stability was improved by providing the space for stable expansion of PANI during capacitive reaction. The specific capacitance estimated by cycle voltammetry was enhanced to 446 Fg(-1) at a scan rate of 5 mV s(-1), while rGO/PANI showed 347 F g(-1). In addition, the rGO/PANI/VC exhibited better rate capability of 87% at 100 mV s(-1) (compared with 85% for the rGO/PANI) and cycle stability of 80% after 2000 cycles at 10 A g(-1) (compared with a 62.9% for the rGO/PANI). It is believed that rGO/PANI/VC with unique structure can be prospective electrode materials for supercapacitors. (C) 2016 Elsevier Ltd. All rights reserved.