Flexible and Freestanding\nMoS₂/Graphene\nComposite for High-Performance Supercapacitors

Abstract

Two-dimensional atomically thick materials such as graphene\nand\nlayered molybdenum disulfide (MoS₂) have been studied as\npotential energy storage materials because of their high specific\nsurface area, potential redox activity, and mechanical flexibility.\nHowever, because of the layered structure restacking and poor electrical\nconductivity, these materials are unable to attain their full potential.\nComposite electrodes made of a mixture of graphene and MoS₂ have been shown to partially resolve these issues in the past, although\ntheir performance is still limited by inadequate mixing at the nanoscale.\nHerein, we report three composites via a simple ball-milling method\nand analyze supercapacitor electrodes. Compared with pristine graphene\nand MoS₂, the composites showed high capacitance. The as-obtained\nMoS₂@Graphene composite (1:9) possesses a high surface\narea and uniform dispersion of MoS₂ on the graphene sheet.\nThe MoS₂@Graphene (1:9) composite electrode has a high\nspecific capacitance of 248 F g^–1 at 5 A g^–1 in an electrochemical supercapacitor compared with the other two\ncomposites. Simultaneously, the flexible symmetric supercapacitor\ndevice prepared demonstrated superior flexibility and a long lifespan\n(93% capacitance retention after 8000 cycles) with no obvious changes\nin performance under different angles. In portable and wearable energy\nstorage devices, the current experimental results will result in scalable,\nfreestanding hybrid electrodes with improved, flexible, supercapacitive\nperformance.