In-situ electrochemical polymerization of multi-walled carbon nanotube/polyaniline composite films for electrochemical supercapacitors

Multi-walled carbon nanotube (MWCNT)/polyaniline (PANI) composite films were prepared by in-situ electrochemical polymerization of an aniline solution containing different MWCNT contents. The super-capacitive behaviors of these films were investigated with cyclic voltammetry (CV), charge-discharge tests, and ac impedance spectroscopy. The results revealed that the MWCNT/PANI films show much higher specific capacitance (SC), better power characteristic, better cyclic stability, and more promising for applications in supercapacitors than a pure PANI film electrode. The highest specific capacitance value of 500 F g(-1) was obtained for the MWCNT/PANI composite film containing MWCNT of 0.8 wt.%. The improvement mechanisms of the capacitance of the composites are also discussed in detail. (C) 2008 Elsevier B.V. All rights reserved.