Controlled growth of NiMoO4·H2O nanoflake and nanowire arrays on Ni foam for superior performance of asymmetric supercapacitors
| Autor: | Chen Qing, Bixiao Wang, Hai Wang, Yiwen Tang, Xiaodan Sun, Daming Sun, Lifeng Xu, Qin Zhou, Yanan Liu, Xiaxia OuYang |
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| Rok vydání: | 2016 |
| Předmět: |
Supercapacitor
Fabrication Materials science business.industry General Chemical Engineering Nanowire Nanotechnology 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Electrochemical energy conversion Capacitance 0104 chemical sciences Electrode Optoelectronics 0210 nano-technology business Power density |
| Zdroj: | RSC Advances. 6:67785-67793 |
| ISSN: | 2046-2069 |
| DOI: | 10.1039/c6ra13483a |
| Popis: | A facile hydrothermal method is developed for fabrication of large-scale NiMoO4·H2O arrays with robust adhesion on Ni foam. Importantly, the morphology of NiMoO4·H2O can be easily controlled to be nanoflake (H-NF) or nanowire (H-NW) arrays by using NH4F as additive. The obtained nanoflake morphology delivers better electrochemical activity than that of nanowire. The electrochemical performance of anhydrous NiMoO4 arrays obtained by annealing the NiMoO4·H2O has also been investigated for comparison. It is believed that the presence of the structural water of NiMoO4 enhances the capacitive performance by making it a good ionic conductor. Furthermore, an asymmetric supercapacitor (ASC) is constructed using the as-prepared NiMoO4·H2O nanoflake arrays as the positive electrode and activated carbon (AC) as the negative electrode. The optimized ASC with an extended operating voltage range of 0–1.6 V displays excellent electrochemical performance with a high energy density of 53.8 W h kg−1 at a power density of 239 W kg−1 in addition to superior rate capability. Moreover, the H-NF//AC ASC device exhibits remarkable cycling stability with 73.4% specific capacitance retention after 4000 cycles. Our result shows that this unique NiMoO4·H2O nanoflake array is promising for electrochemical energy applications. |
| Databáze: | OpenAIRE |
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