عنوان المقالة:A wide potential window symmetric supercapacitor by TEMPO functionalized MWCNTs A wide potential window symmetric supercapacitor by TEMPO functionalized MWCNTs
Gomaa A.M. Ali, E. Megiel, J. Romański, H. Algarni, K.F. Chong
English Authors
Gomaa A.M. Ali, E. Megiel, J. Romański, H. Algarni, K.F. Chong
Abstract
In this paper, we report a simple and effective method to functionalize industrial-grade multi-walled carbon nanotubes (MWCNTs) with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), via oxidation of MWCNTS and followed by carbodiimide coupling of amino-TEMPO. The effective coupling is confirmed and studied by EPR, HRTEM, BET, XPS, FTIR, TGA and XRD techniques. Electrochemical studies reveal the capacitive enhancement of MWCNTs-TEMPO, where MWCNTs-TEMPO shows capacitance value (66 F g−1 at 0.25 A g−1) that is 5-times higher than that of industrial grade MWCNTs (13.5 F g−1 at 0.25 A g−1). This can be due to the reversible redox reaction of nitroxide radicals on TEMPO that contributes to pseudocapacitance. A symmetrical supercapacitor is assembled with MWCNTs-TEMPO as electrode material and optimized with wide operating voltage (2 V) to produce high energy density of 26.6 Wh kg−1 with high stability (90% capacitance retention over 4000 cycles). The findings propose a facile approach to modify industrial grade MWCNTs as the electrode materials in supercapacitors.
جمعه عبدالجواد محمد على | Gomaa A. M. Ali | 20315