Hybrid Transition‐Metal Oxide and Nitride@N‐Doped Reduced Graphene Oxide Electrodes for High‐Performance, Flexible, and All‐Solid‐State Supercapacitors
Lili Jiang, Xiaotong Mei, Donglin Gan, Shaowei Song, Xiaobo Lei, Fanggong Cai, Yaqin Wang, Qinyong Zhang, Xiong Lu, Zhifeng Ren
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.