In the modern era, it is still a challenge to develop an easy, inexpensive, and scalable technique to fabricate an energy storage system. Here, a low-cost and simple process was used to fabricate a silver−polyaniline/multiwalled carbon nanotubes ((Ag-PANI)/MWCNTs) nanocomposite for high-performance supercapacitor electrodes. The possible interactions between Ag and PANI were characterized by Fourier transform infrared and UV−visible spectroscopies. Morphological study confirmed the formation of Ag nanoparticles in the PANI surface, and the MWCNTs were uniformly coated by PANI with the presence of Ag nanoparticles. The nanocomposite showed better electrical conductivity of 4.24 S/cm at room temperature and also attained nonlinear current−voltage characteristics. The highest specific capacitance of 528 F/g has been obtained for the nanocomposite at 5 mV/s scan rate. The nanocomposite also showed better energy as well as power density. Ag-PANI/CNT based supercapacitors with outstanding energy and power density make them a potentially promising candidate for future energy storage systems.

The development of promising microwave absorbing materials is a booming field of research in both the commercial and defense sectors to prevent electromagnetic pollution, and also to enrich the field of stealth technology. Supercapacitors are a symbol of clean energy storage devices. The present work attends to the preparation of hexagonal shaped magnetic M-type hexaferrite, CuFe 10 Al 2 O 19 (CFA) by a facile chemical co-precipitation method, and the formation of its composites (graphene/CFA) in the presence of acid modified graphene. An in situ approach was employed for the coating of graphene with CFA. Another nanocomposite (graphene/CFA/PANI) was prepared by the wrapping of graphene/CFA with polyaniline (PANI), which was prepared through the in situ chemical oxidation polymerization of aniline.The prepared multifunctional nanocomposites showed an outstanding and improved microwave absorption property (the maximum reflection loss was À63.6 dB at a thickness of 2.5 mm with a broad absorption range) and electrochemical properties (the highest specific capacitance value was 342 F g À1 ), in contrast to the pristine graphene and CFA. The addition of PANI also improves the microwave absorption and specific capacitance of the nanocomposites. The formation of the multifunctional nanocomposites and their structural characteristics are discussed thoroughly with their impact on the two different fields of applications i.e. microwave absorbing and energy storage device applications individually.

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The demand for superior energy storage devices, such as supercapacitors, has been growing to meet the application requirements of hybrid vehicles and renewable energy systems. Here, we report a simple method to synthesize manganese chloride (MnCl2)-doped polyaniline (PANI)/single-walled carbon nanotubes (SWCNTs) nanocomposites for electrochemical supercapacitors. The possible interactions between MnCl2 and both PANI and SWCNTs was studied by Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy, and Raman spectroscopy. The morphological characteristics of the electrode materials were investigated by field emission scanning microscopy (FESEM) and transmission electron microscopy (TEM). As-prepared nanocomposites showed higher electrical conductivity of 9.65 S/cm at room temperature and reached nonlinear current–voltage characteristics. A maximum specific capacitance of 546 F/g has been obtained for the nanocomposites at 0.5 A/g current density. Transition metal doping and SWCNTs enhance the electrochemical properties of the nanocomposites. The better specific capacitance and charge/discharge rates make them promising candidates as electrodes in supercapacitors, combining high energy densities with high levels of power delivery.

Copper chloride (CuCl2)‐doped polypyrrole (PPy)/multiwalled carbon nanotube (MWCNTs) nanocomposites were synthesized by an in situ oxidative polymerization method with ammonium persulfate as the oxidant in HCl medium and investigated as electrode materials for supercapacitors. The interaction of metal cations (Cu2+ ions) with PPy was confirmed by Fourier transform infrared spectroscopic analysis. The morphology of the nanocomposites was characterized by field emission scanning electron microscopy and high‐resolution transmission electron microscopy. Electrochemical characterizations of the composites materials were carried out by a three‐electrode probe method, where platinum and a saturated standard calomel electrode were used as the counter and reference electrodes, respectively. A 1M KCl solution was used as the electrolyte for all of the electrochemical characterizations. The transition‐metal‐ion doping enhanced the electrochemical properties of the conducting polymer. Among all of the composites, the CuCl2‐doped PPy/MWCNTs showed the highest specific capacitance value of 312 F/g at a 10 mV/s scan rate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013