標題: | Synthesis of Free-Standing Flexible rGO/MWCNT Films for Symmetric Supercapacitor Application |
作者: | Kumar, Amit Kumar, Nagesh Sharma, Yogesh Leu, Jihperng Tseng, Tseung Yuen 材料科學與工程學系 電子工程學系及電子研究所 Department of Materials Science and Engineering Department of Electronics Engineering and Institute of Electronics |
關鍵字: | Graphene;Reduced graphene oxide;MWCNTs;Specific capacitance;Supercapacitor;Energy and power densities |
公開日期: | 6-八月-2019 |
摘要: | Herein, we report a novel, simple, and cost-effective way to synthesize flexible and conductive rGO and rGO/MWCNT freestanding films. The effects of MWCNT addition on the electrochemical performance of rGO/MWCNT nanocomposite films are investigated in some strong base aqueous electrolytes, such as KOH, LiOH, and NaOH via three-electrode system. The supercapacitor behavior of the films is probed via cyclic voltammetry, galvanostatic charging-discharging, and electrochemical impedance spectroscopy. The structural and morphological studies of the films are performed by X-ray diffractometer, Raman spectrometer, surface area analyzer, thermogravimetric analysis, field emission scanning electron microscope and transmission electron microscope. The rGO/MWCNT film synthesized with 10 wt% MWCNTs (GP10C) exhibits high specific capacitance of 200 Fg(-1), excellent cyclic stability with 92% retention after 15,000 long cycle test, small relaxation time constant (similar to 194 ms), and high diffusion coefficient (7.8457 x 10(-9) cm(2) s(-1)) in 2 M KOH electrolyte. Furthermore, the symmetric supercapacitor coin cell with GP10C as both anode and cathode using 2 M KOH as electrolyte demonstrates high energy density of 29.4 Whkg(-1) and power density of 439 Wkg(-1) at current density 0.1 Ag-1 and good cyclic stability with 85% retention of the initial capacitance at 0.3 Ag-1 after 10,000 cycles. Such a high performance of the GP10C film in the supercapacitor can be ascribed to the large surface area and small hydration sphere radius and high ionic conductivity of K+ cations in KOH electrolyte. |
URI: | http://dx.doi.org/10.1186/s11671-019-3100-1 http://hdl.handle.net/11536/152581 |
ISSN: | 1931-7573 |
DOI: | 10.1186/s11671-019-3100-1 |
期刊: | NANOSCALE RESEARCH LETTERS |
Volume: | 14 |
Issue: | 1 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |