2D nanosheet/3D cubic framework Ni-Co sulfides for improved supercapacitor performance via structural engineering.

The construction of multi-dimensional structured battery-type electrode materials is a promising strategy to develop high performance electrodes for supercapacitors. Herein, a series of battery-type Ni3S2@Co3S4 electrodes with different morphologies are synthesized by controlling the hydrothermal reaction time. Owing to the unique structure with independent but interconnected 2D nanosheets and 3D cubic frameworks, NCS-60 displays high conductivity, numerous active sites and good wettability behavior. It can deliver a high specific capacity of 388.9 mA h g(-1)(3500 F g(-1)) at 1 A g(-1), an outstanding rate capacity of maintaining 88.6% at 10 A g(-1)and long cycle stability. The battery-type supercapacitor hybrid (BSH) device with active carbon (AC) as the negative electrode delivers an energy density of 41.8 W h kg(-1)at the power density of 800 W kg(-1). This study provides a feasible route for regulating the morphologies ofin situgrowth materials that improve the electrochemical performance of supercapacitors.