Network-like holey NiCo2O4 nanosheet arrays on Ni foam synthesized by electrodeposition for high-performance supercapacitors.

To achieve high-performance supercapacitors, electrode materials with the accessible electrode area, electrons, and ions diffusion channels are strongly needed. Herein, the network-like holey NiCo2O4 nanosheet arrays grown on Ni foam have been synthesized by a facile and efficient electrodeposition followed by calcination as a binder-free electrode for supercapacitors. The nanosheets are interconnected and interlocked together to form a network-like structure with abundant open channels, and the arrays are about 2.3 μm in thickness. Interestingly, the holey nanosheets include numerous macropores (50-160 nm) and mesopores (3-10 nm), which contribute to the rapid electrolyte ions diffusion between the nanosheet layers and the increase of capacitances. The NiCo2O4 nanosheet arrays electrode displays a high capacitance of 2.23 F cm−2 (1012.5 F g−1) at a current density of 5 mA cm−2, good rate capability of 67.3% at a current density of 50 mA cm−2, and high-cycling stability. These results indicate that the network-like holey NiCo2O4 nanosheet arrays electrode has a significant potential application in supercapacitors. [ABSTRACT FROM AUTHOR]