Fabrication of FeCo2S4/Ag NWs/G Ternary Nanocomposites with Honeycomb-Like Nanostructure for High-Performance Supercapacitors

Ferric cobalt sulfide/silver nanowires/graphene (FeCo2S4/Ag NWs/G) ternary nanocomposites with hierarchical honeycomb-like morphology have been obtained through hydrothermal synthesis. In the FeCo2S4/Ag NWs/G composite electrode, the Ag NWs provide effective electron transport channels and prevent the graphene and FeCo2S4 nanosheets from aggregating. The graphene sheets can not only provide connected channels for ion transportation and charge transfer but also significantly buffer the volume change of electrode. As a result, the as-prepared FeCo2S4/Ag NWs/G composite electrode exhibits a high specific capacitance of 2689.2 F/g at a current density of 1 A/g, and excellent capacitance retention of 96.1% after 5000 charge–discharge cycles. In addition, an asymmetric supercapacitor was fabricated using FeCo2S4/Ag NWs/G as positive electrode and flower-like hierarchical porous nitrogen-doped carbon sphere as negative electrode. The assembled supercapacitor delivered a high energy density of 80.6 Wh/kg at a power density of 806 W/kg. These results demonstrate that such FeCo2S4/Ag NWs/G nanocomposites have widespread application prospects in the field of electrochemical energy storage.