Hybrid Transition-Metal Oxide and Nitride@N-Doped Reduced Graphene Oxide Electrodes for High-Performance, Flexible, and All-Solid-State Supercapacitors.

Nanoscale composites for high-performance electrodes employed in flexible, all-solid-state supercapacitors are being developed. A series of binder-free composites, each consisting of a transition bimetal oxide, a metal oxide, and a metal nitride grown on N-doped reduced graphene oxide (rGO)-wrapped nickel foam are obtained by using a universal strategy. Three different transition metals, Co, Mo, and Fe, are separately compounded with nickel ions, which originate from the nickel foam, to form three composites, NiCoO @Co O @Co N, NiMoO @MoO @Mo N, and NiFe O @Fe O @Fe N, respectively. These as-prepared active materials have similar regular variation patterns in their properties, including better conductivity and battery-mimicking pseudocapacitance, which result in their high whole-electrode capacitance performance [2598.3 F g (39.85 F cm ), 3472.6 F g (41.43 F cm ) and 1907.5 F g (3.41 F cm ) for the composites incorporating Co, Mo, and Fe, respectively]. The as-assembled flexible, all-solid-state NiCoO @Co O @Co N//KOH/PVA//NiCoO @Co O @Co N device can be easily bent and exhibits high energy density and power density of 92.8 Wh kg and 1670.4 W kg , respectively. The universality of this design strategy could allow it to be employed in producing hybrid materials for high-performance energy-storage devices.