Synthesis of porous flower-like Ni-Co-Mo-S nanostructures on Ni foam for battery-supercapacitor hybrid devices

The synergistic effects of multiple components and unique nanostructures were contributed to prepare the high-performance battery-type electrode materials. In this work, Mo element was introduced to form the ternary transition metal oxides/hydroxides of Ni-Co to improve conductivity, and then charge transfer was accelerated to enhance the capacity storage. After sulfidation, the electrical conductivity was further improved, and a porous flower-like nanostructure was formed. Except for that, the composites of transition metal oxides/hydroxides and sulfides were formed via sulfidation. With the help of the synergistic effects of multiple components and a porous flower-like nanostructure, more Faradic redox reactions occurred. Therefore, the as-prepared porous flower-like Ni-Co-Mo-S nanostructures on Ni foam exhibited an excellent areal capacitance of 7.22 C center dot cm(-2) at 5 mA center dot cm(-2) and long-cycle stability (96.9% retention after 5000 cycles). Furthermore, a coin-type battery-supercapacitor hybrid (BSH) device was assembled, which achieved 54.54 Wh center dot kg(-1) at 540 W center dot kg(-1) and displayed 74.8% capacitance retention after 3500 cycles. All mentioned above demonstrated that ternary transition metal oxides/hydroxides precursors via sulfidation can form special structures and the composites of transition metal oxides/hydroxides and sulfides to prepare high-performance battery-type electrodes for energy storage.