Confined space synthesis of Ni(OH)2-impregnated three-dimensional ordered mesoporous carbon as a high-performance supercapacitor electrode

Abstract

Regulable loading of Ni(OH)2 crystals by using three dimensionally ordered mesoporous carbon (3DOMC) as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization. Dual forms of high-crystalline nanosheet-like Ni(OH)2 severally distribute within mesopores or over the outer surface of 3DOMC particles depending on the loading amount (3% − 15%) of Ni(OH)2. Benefitted from the highly hybrid combination and efficient electrolyte diffusion, the obtained Ni(OH)2/carbon nanocomposites exhibit an excellent electrochemical performance, and the optimal sample of 6%_Ni(OH)2/3DOMC with confined extra-small Ni(OH)2 nanosheets as dominant shows the highest specific capacitance of 552.5F.g−1 at 1.0A·g−1, which is 330% higher than the contrast sample by using actived carbon as the support. Furthermore, the assembled hybrid supercapacitor by using 6%_Ni(OH)2/3DOMC and 3DOMC as positive and negative electrodes displays an energy density of 11.7 Wh.kg−1 at 288.1 W.kg−1 and a superior charge/discharge stability. It is expected that the flexible component, well-defined structure, and superior electrochemical performance could promote a great application potential of Ni(OH)2/3DOMC nanocomposites as supercapacitor electrodes and in other energy storage devices.

Keywords

• Composite electrodes
• Mesoporous carbon
• Ni(OH)2
• Confined space synthesis
• Supercapacitors