NiCo2S4 nanosheet/Co9S8 hollow nanoparticle derived from MOF hierarchical core/shell electrode material for supercapacitor applications

Hierarchically engineered three-dimensional (3D) nanostructures are interesting materials for supercapacitors application due to their excellent accessible active sites, and enhanced mass transport and diffusion. However, the design of robust 3D hierarchical core/shell nanostructures with good electrical conductivity and large accessible active site is still challenging. Herein, a 3D honeycomb-like NiCo2S4 nanosheet/Co9S8 hollow derived from metal–organic framework (MOF) hierarchical core/shell electrode material for supercapacitor application is reported. The synthesized 3D hierarchical core/shell structure endowed open diffusion channels and good active sites. This hierarchical core/shell structure exhibits a high areal-specific capacitance of 13.04 F cm−2 at current density of 10 mA cm−2; excellent rate performance of 77% as current density increased from 5 to 80 mA cm−2; and an excellent cycle stability of 94% after 6000 cycles of charge–discharge. Furthermore, the asymmetric electrode device made of NF/NCS/HCS//rGO showed an excellent energy density of 36.9 Wh kg−1 at a power density of 800 W kg−1. Such impressive results suggest promising applications of MOF-derived hierarchical structures for design of advanced energy storage devices.