Facile preparation and sulfidation analysis for activated multiporous carbon@NiCo2S4 nanostructure with enhanced supercapacitive properties

A facile two-step hydrothermal method is modified to synthesize NiCo2S4 nanosheets on activated multiporous carbon (AMC) for application in supercapacitors. The structure and performance of both NiCo2S4 and the intermediate product, i.e. NiCo2O4 on AMC are investigated in detail to clarify the effect of the sulfidation treatment. Owing to the high electronic conductivity of NiCo2S4, the unique designed nanostructure exhibits a high specific capacitance (651.1 F g−1 at 0.6 A g−1), good rate performance (88.1% retention for current increases around 17 times) and excellent cycling stability (87.4% retention after 2000 cycles). These results suggest this hybrid composite to be a promising electrode material for high-performance supercapacitors and the rational fabrication provides an approach to improve the electrochemical energy storage for other transition metal sulfides and oxides.