Freestanding core-shell Ni(OH)2@MnO2 structure with enhanced energy density and cyclic performance for asymmetric supercapacitors
| Autor: | Dachun Peng, Xiaohong Xia, Qian Ma, Yuxi Chen, Hui Chen, Ruohan Shen, Hongbo Liu, Wenming Hu |
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| Rok vydání: | 2019 |
| Předmět: |
Supercapacitor
Materials science Mechanical Engineering Metals and Alloys Shell (structure) 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Capacitance 0104 chemical sciences Core shell Chemical engineering Mechanics of Materials Electrode Materials Chemistry medicine Energy density 0210 nano-technology Activated carbon medicine.drug Power density |
| Zdroj: | Journal of Alloys and Compounds. 803:866-874 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2019.06.368 |
| Popis: | Core-shell structural Ni(OH)2@MnO2 electrodes with widened potential window and great stability are prepared through a two-step strategy, in which freestanding Ni(OH)2 discs grow on nickel-foam as core and wrinkled MnO2 coatings are electrodeposited as shell. The MnO2 shell successfully inhibits the O2 evolution process at the high oxidation potential so that the potential window of Ni(OH)2@MnO2 electrode is up to 1 V. Besides, the Ni(OH)2@MnO2 electrode presents a high specific capacity of 642.3 C g−1 at 1 mV s−1 and a long cyclic life without capacity fading, which is a breakthrough against the poor stability of reported Ni(OH)2/MnO2 electrodes Remarkably, an asymmetric supercapacitor (ASC) constructed by Ni(OH)2@MnO2 electrode and activated carbon electrode delivers a high energy density of 66.7 Wh kg−1 at a power density of 485.7 W kg−1 under potential window of 1.7 V. Furthermore, the ASC exhibits an energy density of 17.8 Wh kg−1 at a high power density of 14571.4 W kg−1 and a capacitance retention of 101.4% after 15,000 cycles, showing great rate capability and stable cyclic performance. |
| Databáze: | OpenAIRE |
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