β-Ni(OH)2/nickel-cobalt layered double hydroxides coupled with fluorine-modified graphene as high-capacitance supercapacitor electrodes with improved cycle life
| Autor: | Fanggang Li, Li Ma, Hao Yuan, Yuxiu You, Wenzhong Shen, Maojun Zheng, Wenlan Zhang, Dongkai Jiang |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Supercapacitor
Materials science Graphene Mechanical Engineering Metals and Alloys Layered double hydroxides 02 engineering and technology engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Capacitance Exfoliation joint 0104 chemical sciences law.invention Chemical engineering Mechanics of Materials law Electrode Materials Chemistry engineering Graphite 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 875:159929 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2021.159929 |
| Popis: | As energy consumption grows, the demand for a new generation of high-security, long-life and large-capacity power supplies is growing rapidly. Here we demonstrate a facile and binder-free strategy to obtain β-Ni(OH)2/nickel–cobalt layered double hydroxides (β-Ni(OH)2/NiCo-LDH) coupled with fluorine-modified graphene (FG) as supercapacitor electrodes (β-Ni(OH)2/NiCo-LDH@FG) via hydrothermal method, synchronous electrochemical exfoliation of graphite into fluorine-modified graphene and assembly on β-Ni(OH)2/NiCo-LDH. This hybrid structure of β-Ni(OH)2/NiCo-LDH and modified graphene as supercapacitor electrode displays high conductivity, high ion diffusivity and strong mechanical strength. As a result, the β-Ni(OH)2/NiCo-LDH@FG electrode possesses excellent capacitance (3996 mF cm−2 at 1 mA cm−2), remarkable rate capability and improved cycle life. The β-Ni(OH)2/NiCo-LDH coupled with undoped electrochemically exfoliated graphene exhibits the significantly improved cycle stability (79% capacitance retention after 1000 cycles at 5 mA cm−2), superior to that of β-Ni(OH)2/NiCo-LDH (31%). Therefore, this strategy has great potential to improve the performance of electrodes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect