Design of Ni(OH) Nanosheets@NiMoO Nanofibers' Hierarchical Structure for Asymmetric Supercapacitors.

Transition-metal-based materials show great promise for energy conversion and storage due to their excellent chemical properties, low cost, and excellent natural properties. In this paper, through simple strategies such as classical electrospinning, air calcination, and the one-step hydrothermal method, a large area of Ni(OH) nanosheets were grown on NiMoO nanofibers, forming NiMoO@Ni(OH) nanofibers. The one-dimensional nanostructure was distributed with loose nanosheets, and this beneficial morphology made charge-transfer and diffusion more rapid, so the newly developed material showed good capacitance and conductivity. Under the most suitable experimental conditions, the optimal electrode exhibited the highest specific capacitance (1293 F/g at 1 A/g) and considerable rate capability (56.8% at 10 A/g) under typical test conditions. Most interestingly, the corresponding asymmetrical capacitors exhibited excellent electrochemical cycle stability, maintaining 77% of the original capacitance. NiMoO@Ni(OH) nanofibers were verified to be simple to prepare and to have good performances as energy-storage devices within this experiment.