▎ 摘　　要

To meet a fast-emerging demand, flexible energy storage applications have a great interest in the development of highly flexible hierarchical nanoarchitectures. Metal nitrides have recently been paid a significant interest as a promising electrode material for supercapacitors (SCs) owing to their high electrical conductivity, excellent redox properties, and outstanding mechanical strength. However, poor electrochemical stability seriously limits the commercialization possibilities. Herein, a novel strategy is presented for the synthesis of nitrogen-doped graphene encapsulated with ultrasmall nickel-cobalt nitride (NiCo2N) and nickel-iron nitride (NiFeN) core-shell architectures that are explored as advanced electrodes for flexible solid-state SC. The flexible NiCo2N@NG//NiFeN@NG asymmetric SC delivers an ultrahigh energy density of approximate to 94.93 Wh kg(-1) at 0.79 kW kg(-1), exceptional power density (approximate to 74.67 Wh kg(-1) at 39.53 kW kg(-1)), and ultralong cycle life (approximate to 5.07% drop in initial capacity after 25 000 cycles). These results promote the core-shell hybrids that can be served as advanced supercapacitor materials for flexible energy storage applications.