Facile synthesis of three-dimensional NiCo2O4 with different morphology for supercapacitors

Three-dimensional (3D) hierarchical NiCo 2 O 4 with tremella-like, flower-like, urchin-like and pine-needle-like structures has been prepared through a facile hydrothermal method. The key roles of the alkali source and NH 4 F in the formation of these nanostructures have been investigated. When applied to supercapacitors as an electrode material, the urchin-like NiCo 2 O 4 sample exhibits the optimal electrochemical performance among all the four samples, demonstrating its promising application potential for supercapacitors. Such excellent performance is attributed to the unique mesoporous structure of the superfine nanoneedle-assembled urchin-like NiCo 2 O 4 with large specific surface area. This investigation about morphology control of NiCo 2 O 4 electrode materials and the relationship between the morphologies and corresponding electrochemical performances also provides a reference for the rational design and synthesis of electrode materials with desirable morphology for high performance supercapacitor applications. The morphology of NiCo 2 O 4 can be controlled by changing the kinds of alkali source and the addition of NH 4 F, influencing its electrochemical properties.