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Abstract Core-shell-structured system has been proved as one of the best architecture for clean energy products owing to its inherited superiorities from both the core and the shell part, which can provide better conductivity and high surface area. Herein, a hierarchical core-shell NiCo2S4@NiMoO4 heterostructure nanotube array on Ni foam (NF) (NiCo2S4@NiMoO4/NF) has been successfully fabricated. Because of its novel heterostructure, the capacitive performance has been enhanced. A specific capacitance up to 2006 F g-1 was obtained at a current density of 5 mA cm-2, which was far higher than that of pristine NiCo2S4 nanotube arrays (about 1264 F g-1). More importantly, NiCo2S4@NiMoO4/NF and active carbon (AC) were congregated as positive electrode and negative electrode in an asymmetric supercapacitor. As-fabricated NiCo2S4@NiMoO4/NF//AC device has a good cyclic behavior with 78% capacitance retention over 2000 cycles, and exhibits a high energy density of 21.4 Wh kg-1 and power density of 58 W kg-1 at 2 mA cm-2. As displayed, the NiCo2S4@NiMoO4/NF core-shell herterostructure holds great promise for supercapacitors in energy storage.

Core-shell-structured system has been proved as one of the best architecture for clean energy products owing to its inherited superiorities from both the core and the shell part, which can provide better conductivity and high surface area. Herein, a hierarchical core-shell NiCoS@NiMoO heterostructure nanotube array on Ni foam (NF) (NiCoS@NiMoO/NF) has been successfully fabricated. Because of its novel heterostructure, the capacitive performance has been enhanced. A specific capacitance up to 2006 F g was obtained at a current density of 5 mA cm, which was far higher than that of pristine NiCoS nanotube arrays (about 1264 F g). More importantly, NiCoS@NiMoO/NF and active carbon (AC) were congregated as positive electrode and negative electrode in an asymmetric supercapacitor. As-fabricated NiCoS@NiMoO/NF//AC device has a good cyclic behavior with 78% capacitance retention over 2000 cycles, and exhibits a high energy density of 21.4 Wh kg and power density of 58 W kg at 2 mA cm. As displayed, the NiCoS@NiMoO/NF core-shell herterostructure holds great promise for supercapacitors in energy storage. [ABSTRACT FROM AUTHOR]

Three dimensional (3D) hierarchical network configurations are composed of NiCo2S4 nanotube @Ni-Mn layered double hydroxide (LDH) arrays in situ grown on graphene sponge. The 3D graphene sponge with robust hierarchical porosity suitable for as a basal growth has been obtained from a colloidal dispersion of graphene oxide using a simple directional freeze-drying technique. The high conductive NiCo2S4 nanotube arrays grown on 3D graphene shows excellent pseudocapacity and good conductive support for high-performance Ni-Mn LDH. The 3D NiCo2S4@Ni-Mn LDH/GS shows a high specific capacitance (Csp) 1740 mF cm(-2) at 1 mA cm(-2), even at 10 mA cm(-2), 1267.9 mF cm(-2) maintained. This high-performance composite electrode proposes a new and feasible general pathway as 3D electrode configuration for energy storage devices.