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A binder‐free supercapacitor electrode of NiCo2O4 nanograss coated on nickel foam (NF) was prepared by single‐mode microwave method along with calcination, displaying a higher specific capacitance (1042 F/g at 1 mV/s). Furthermore, we demonstrate excellent electrochemical performance of NiCo2O4 nanograss as anode electrode and carbide‐derived carbon as cathode electrode. The resultant asymmetric supercapacitors possess high specific capacitance (105.6 F/g at 1 mV/s), good cycling stability (retention capacitance of 78.5% after 5000 cycles), high energy density (32.9 Wh/kg) and large power density (970.1 W/kg), which has potential application in energy storage devices. [ABSTRACT FROM AUTHOR]

In this work, we demonstrate the synthesis of three-dimensional hierarchical nanostructured cobalt disulfide/molybdenum disulfide growth on carbon fiber cloth (CoS 2 /MoS 2 /CC) for hydrogen evolution reaction and supercapacitor. CoS 2 nanoparticles anchor on flower-like MoS 2 nanosheets grown on CC by a two-step procedure via facile single mode microwave-assisted hydrothermal technique. It was observed that CoS 2 /MoS 2 nanocomposites were uniformly dispersed on CC and CoS 2 nanoparticles were wrapped by flower-like MoS 2 nanosheets. Remarkably, the binder-free CoS 2 /MoS 2 /CC maintains its activity after 1000 cycles and exhibits superior catalytic activity in hydrogen evolution reaction, with a low overpotential of 177 mV to achieve current density of 10 mA cm −2 and a Tafel slope of 66 mV dec −1 . Furthermore, the bifunctional CoS 2 /MoS 2 /CC for supercapacitor delivers a higher specific capacitance of 406 F/g and excellent long-life cycling stability, retaining 95.27% of the initial capacitance after 10000 cycles. The enhanced hydrogen evolution reaction and supercapacitor property may be ascribed to the synergistic effect between metallic CoS 2 and MoS 2 , moreover more electrochemical accessible active sites and fast electron transport path can be obtained. [ABSTRACT FROM AUTHOR]

Porous nanostructure composites materials had attracted widely attention due to their potential application in energy storage (Lithium ion batteries (LIBs) and supercapacitor) and electrocatalyst of oxygen evolution reaction (OER). Co 3 O 4 @CoO@Co@C nanocomposites had been successfully synthesized using glucose as carbon source and cobalt nitrate as metalprecurs or of Co 3 O 4 @CoO@Co@C, which has excellent electrochemical performance for LIBs, supercapacitor and OER. Three kinds of morphology samples marked by Co 3 O 4 @CoO@Co@C-2/1, Co 3 O 4 @CoO@Co@C-1/1 and Co 3 O 4 @CoO@Co@C-1/2 are synthesized due to different atomic ratio of cobalt/carbon in precursors. Electrochemical and catalytic performance of Co 3 O 4 @CoO@Co@C-2/1 nanocomposites is more excellent than Co 3 O 4 @CoO@Co@C-1/1 and Co 3 O 4 @CoO@Co@C-1/2. Co 3 O 4 @CoO@Co@C-2/1 shows that discharge capacity can maintain 450 mA h g −1 and coulombic efficiency is nearly 100% during 500 cycles for LIBs. It indicates the excellent cycling stability of Co 3 O 4 @CoO@Co@C-2/1 as electrode for supercapacitor that about 78.3% of initial specific capacitance can be retained after 10000 cycles at current density of 2 A g −1 . Co 3 O 4 @CoO@Co@C-2/1 as catalyst of OER shows excellent electrochemical durability over 15 hours continuous experiment. [ABSTRACT FROM AUTHOR]