Thermally reduced fluorographenes as efficient electrode materials for supercapacitors
| Autor: | Radek Zbořil, Vojtěch Kupka, Piotr Błoński, Martin Petr, Petr Jakubec, Václav Ranc, Josef Kašlík, Michal Otyepka, Veronika Šedajová, Miroslav Medveď, Rostislav Langer |
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| Jazyk: | angličtina |
| Předmět: |
Supercapacitor
Electrode material Materials science chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 7. Clean energy 01 natural sciences Durability Capacitance Isothermal process 0104 chemical sciences chemistry Chemical engineering Fluorine General Materials Science 0210 nano-technology Fluorographene Current density |
| Zdroj: | Nanoscale |
| ISSN: | 2040-3372 2040-3364 |
| DOI: | 10.1039/c9nr07255a |
| Popis: | There is an urgent need for a simple and up-scalable method for the preparation of supercapacitor electrode materials due to increasing global energy consumption worldwide. We have discovered that fluorographene exhibits great potential for the development of new kinds of supercapacitors aimed at practical applications. We have shown that time control of isothermal reduction of fluorographite at 450 °C under a hydrogen atmosphere led to the fine-tuning of fluorine content and electronic properties of the resulting fluorographene derivatives. Charge transfer resistances (Rct) of the thermally reduced fluorographenes (TRFGs) were decreased with respect to the pristine fluorographene; however, the Rctvs. time-of-reduction plot showed a v-shaped profile. The specific capacitance vs. time-of-reduction of TRFG followed the v-shaped trend, which could be the result of the decreasing content of sp3 carbons and increasing content of structural defects. An optimized material exhibited values of specific capacitance up to 539 F g−1 recorded at a current density of 0.25 A g−1 and excellent cycling durability with 100% specific capacitance retention after 1500 cycles in a three-electrode configuration and 96.7% of specific capacitance after 30 000 cycles in a two-electrode setup. |
| Databáze: | OpenAIRE |
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