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

Abstract

Abstract 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 2 @Co 3 O 4 @Co 2 N, NiMoO 4 @MoO 3 @Mo 2 N, and NiFe 2 O 4 @Fe 3 O 4 @Fe 2 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 −1 (39.85 F cm −2 ), 3472.6 F g −1 (41.43 F cm −2 ) and 1907.5 F g −1 (3.41 F cm −2 ) for the composites incorporating Co, Mo, and Fe, respectively]. The as‐assembled flexible, all‐solid‐state NiCoO 2 @Co 3 O 4 @Co 2 N//KOH/PVA//NiCoO 2 @Co 3 O 4 @Co 2 N device can be easily bent and exhibits high energy density and power density of 92.8 Wh kg −1 and 1670.4 W kg −1 , respectively. The universality of this design strategy could allow it to be employed in producing hybrid materials for high‐performance energy‐storage devices.