Hierarchical CuCo Carbonate Hydroxide Nanowires@FeCo-Layered Double Hydroxide Hexagonal Nanosheets of Penetrating Architecture for High-Performance Asymmetric Supercapacitor

Rational construction of heterostructures can compensate for the property shortfalls of a single component, which is a promising and challenging approach to develop high-performance electrode materials. Herein, CuCo carbonate hydroxide nanowires@FeCo-layered double hydroxide hexagonal nanosheets (CuCo-CH@FeCo-LDH) with a unique nanowire-penetrated-nanosheet architecture have been prepared through a facile two-step hydrothermal method. The nanowires serve as fast channels for charge transfer of FeCo-LDH and alleviate the blocked electroactive utilization induced by self-stacking of LDH nanosheets, while the FeCo-LDH contributes high specific capacitance. The resultant CuCo-CH@FeCo-LDH exhibits pseudocapacitive behavior with near-rectangular CV profiles and overall enhanced electrochemical performance compared to individual CuCo-CH and FeCo-LDH. An assembled asymmetric supercapacitor (CuCo-CH@FeCo-LDH//N/S co-doped graphene) delivers high energy density (46.9 Wh kg(-1) at 750 W kg(-1)), high power density (29.0 Wh kg(-1) at 7500 W kg(-1)), and outstanding cycling stability (81.7 % capacitance retention after 5000 cycles).