In situ preparation of caterpillar-like polyaniline/carbon nanotube hybrids with core shell structure for high performance supercapacitors

An easy and cost-effective approach was developed to deposit polyaniline (PANI) on a single graphitized multiwalled carbon nanotube (GMWCNT) by in situ chemical polymerization. The GMWCNTs were previously grafted with poly(4-vinylpyridine) (P4VP). The morphology and composition of the as-prepared PANI/P4VP-g-GMWCNT hybrids were characterized by the Fourier transform infrared spectroscopy, thermogravimetric analysis and transmission electron microscopy (TEM). The TEM images reveal these PANI/P4VP-g-GMWCNT hybrids possess a core shell structure and take shape as caterpillar. The storage energy performance was investigated by cyclic voltammetry, galvanostatic charge/discharge tests and electrochemical impedance spectroscopy. The PANI/P4VP-g-GMWCNT hybrids exhibit a high specific capacitance up to 1065 F g−1 and a long cyclic durability with 92.2% capacitance retention over 1000 cycling. A comparative study was carried out between PANI covered on the GMWCNTs with P4VP (PANI/P4VP-g-GMWCNT) and those without P4VP (PANI/GMWCNT). The PANI/P4VP-g-GMWCNT hybrids are superior to PANI/GMWCNT in term of specific capacitance, rate capability and cyclic stability due to their unique structure and full coverage of PANI on the GMWCNTs.