High performance asymmetric supercapacitor based on molybdenum disulphide/graphene foam and activated carbon from expanded graphite

Molybdenum disulphide which has a graphene-like single layer structure has excellent mechanical and electrical properties and unique morphology, which might be used with graphene foam as composite in supercapacitor applications. In this work, Molybdenum disulphide (MoS2)/graphene foam (GF) composites with different graphene foam loading were synthesized by the hydrothermal process to improve on specific capacitance of the composites. Asymmetric supercapacitor device was fabricated using the best performing MoS2/GF composite and activated carbon derived from expanded graphite (AEG) as positive and negative electrodes, respectively, in 6 M KOH electrolyte. The asymmetric MoS2/GF//AEG device exhibited a maximum specific capacitance of 59 F g(-1) at a current density of 1 A g(-1) with maximum energy and power densities of 16 W h kg(-1) and 758 W kg(-1), respectively. The supercapacitor also exhibited a good cyclic stability with 95% capacitance retention over 2000 constant charge-discharge cycles. The results obtained demonstrate the potential of MoS2/GF/AEG as a promising material for electrochemical energy storage application. (C) 2016 Elsevier Inc. All rights reserved.