Sulphur-functionalized graphene towards high performance supercapacitor

To enhance the energy densities, pseudocapacitive materials are usually added to electric double layer carbonaceous materials. However in the process of energy densities enhancement, power densities are usually lowered which creates a dilemma situation for researchers. Thus to obtain high energy and power densities, a new pseudocapacitive mechanism, to the best of our knowledge, is introduced in this paper. High supercapacitive performance can be obtained by the redox mechanism of thiocarboxylic acid ester to sulphone with the aid of external current. The specific capacitance of the material is enhanced to as high as 1089 F g(-1) at 1 A g(-1), and even at high current density of 50 A g(-1), it is able to discharge a respectable 833 F g(-1). The material is able to exhibit high energy density of 43 Wh kg(-1) at high power density of 38 kW kg(-1) which validates the possibility of a harmonious coexistence between high energy density and high power density. (C) 2014 Elsevier Ltd. All rights reserved.