NiCo2O4 nanostructure materials: morphology control and electrochemical energy storage.

Three types of NiCo₂O₄ nanostructure, homogeneous NiCo₂O₄ nanoneedle arrays, heterogeneous NiCo₂O₄ nanoflake arrays and NiCo₂O₄ nanoneedle-assembled sisal-like microspheres are synthesized via facile solution methods in combination with thermal treatment. The NiCo₂O₄ nanoneedle arrays are evaluated as supercapacitor electrodes and demonstrate excellent electrochemical performances with a high specific capacitance (923 F g^-1 at 2 A g^-1), good rate capability, and superior cycling stability. The superior capacitive performances are mainly due to the unique one dimensional porous nanoneedle architecture, which provides a faster ion/electron transfer rate, improved reactivity, and enhanced structural stability. The fabrication method presented here is facile, cost-effective and scalable, which may open a new pathway for real device applications. [ABSTRACT FROM AUTHOR]