One-step preparation of 3D binder-free electrode of porous Co-Mo-S nanostructures grown on Ni foam for supercapacitors

Transition metal chalcogenides have wide studied as active electrode materials for electrochemical storage devices. In this study, we successfully fabricated a binder-free electrode of hierarchical Co-Mo-S nanosheets on nickel foam (CMS/NF) by a facile hydrothermal method under microwave irradiation. The CMS layer, with a thickness of a few nanometers, was decorated on the NF's surface. Taking advantage of the large specific surface area of NF and the high capacitance and porosity of CMS, the prepared electrode is believed to have a rapid electron and ion transport, large electroactive sites, and excellent cycle stability. The specific capacitance of 1080 F g−1 at 1 A g−1 and excellent cycling stability (90.4% retention in specific capacitance after 5000 cycles) were obtained. For further practical applications, an asymmetric supercapacitor was assembled using the CMS/NF as the cathode and the activated carbon as anode material. The prepared device exhibited a high capacitance of 47 F g−1 at 1 A g−1 and a high energy density of 42.6 Wh kg−1 at a power density of 850.3 W kg−1 at a wide operating voltage of 1.6 V. This current method could provide a rapid one-step process for other 3D porous electrodes for high-performance supercapacitors.