Summary In this study, excellent performance and wide operating voltage are obtained with an aqueous electrolyte. Aqueous electrolytes are attracted more attention than other electrolytes (such as organic solvents, ionic liquids) in supercapacitor applications because of their safety, low cost, nontoxicity. Polypyrrole (PPy), aniline 2‐sulfonic acid (ASA) modified electrodes are hydrothermal synthesized on carbon felt (CFt) for supercapacitor applications. We investigate the presence of the concentration of ASA on the polymerization of the PPy. Furthermore, a high operating voltage of 3.0 V asymmetric supercapacitor (ASC) with graphite plate is assembled 3 M KCI. CFt/PPy/ASA(0.02)//GP exhibits a high specific capacitance value of 902.9 F g−1 at 5 mV s−1 and after 5000 cycle‐life testing 93.6% capacitance retention at a scan rate of 1000 mV s−1. The assembled ASC has an ultrahigh‐energy density of 1005 Wh kg−1 while delivering a power density of 3000 W kg−1 at a current density of 2 A g−1. The effect of ASA concentration on the supercapacitor performance has been observed.

In this study, Fe‐doped polyaniline/dye‐functional composite modified carbon felt electrode was synthesized using hydrothermal method and a supercapacitor exhibiting 1.5 V was obtained with 3.0 M KCl aqueous electrolyte. In order to improve supercapacitor performance easily and effectively, the effect of Lanaset Green B (LGB) acidic dye concentration on supercapacitor performance in polyaniline polymerization was investigated. Electrochemical, morphological and structural characterizations of the synthesized electrodes (CFt/Fe‐PANI/LGB) were carried out. The results showed that the capacitance increases due to the strong interaction of functional groups between PANI and dye molecules and improves the properties of pseudocapacitive supercapacitors by providing potential redox materials. The CFt/Fe‐PANI/LGB(3 mM) electrode displayed a high specific capacitance of 1543 F g−1 at a scan rate of 5 mV s−1 in half‐cell electrode system. In full‐cell, the assembled symmetric supercapacitor has a maximum energy density of 32.7 Wh kg−1 and power density of 1250 W kg−1. The supercapacitor electrode and symmetric supercapacitor display retention of capacitance performances 82.3 % and 78.8 % after 2400 and 5000 cycles in 3.0 KCl electrolyte, respectively. CFt/Fe‐PANI/LGB(3 mM), flexible, wearable carbon felt electrode material and improved redox behavior of the polymer material play an important role for textile electronics applications.

Conducting polymer and carbon-based materials are important in supercapacitor applications as capacitive materials. However, the use of these materials alone limits their application due to poor rate capability and short lifetime or low capacitance. Herein, the supercapacitor electrodes were successfully synthesized by two step process on the carbon-felt. Firstly, S-GO, N-GO and Cl-GO was obtained by chronoamperometry method at room temperature. After, PANI composites were synthesized through a hydrothermal method with S, N and Cl heteroatom doped graphene oxide powders. The best specific capacitance for Cl-GO doped PANI (PANI/Cl-GO) electrode reaches 1217 mFcm−2 (608.3 Fg-1) at 4 A g−1 and, significantly higher that the results of PANI and other hybrids. Moreover, the symmetric supercapacitor using PANI/Cl-GO electrodes demonstrates excellent long-life performance after 5000 cycle (96.9 %). The device has a maximum energy density of 42.8 Wh kg-1 while delivering a power density of 250 W kg-1.

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In this study, sunflower, corn, peanut and hazelnut oils were investigated according to their oxidative stability and antioxidant activity parameters. The related vegetable oils were treated with gallic acid, rutin and carotenoid. Olive leaf extract having a large variety of phytochemical was also valorized. After the leaf samples were extracted through a homogenizer, they were added into the vegetable oils, respectively. Moreover, synthetic antioxidants were also dissolved into the oils for control reasons. Stability of the vegetable oils against the oxidation was evaluated via Rancimat by measuring induction time. The quality parameters of treated and untreated oil samples were compared depending on phenolic and carotenoid contents, antioxidant activity and induction time.

Facile one-step electrochemical synthesis of a novel graphitic oxide/polypyrrole/2-acrylamido-2-methyl-1-propanesulfonic acid composite on carbon fabric were described for development of an efficient positive electrode for supercapacitor applications. The 2-acrylamido-2-methyl-1-propanesulfonate monomers behave as dopant in 3D polypyrrole network formed by synergetic coupling with graphitic oxide. Their free acrylic groups interact with each other to form polymer-hydrogel-layer on the external surface that facilitate transport of aqueous electrolyte ions inside of the electrode. The most efficient electrode material was synthesized by tuning dopant concentration at 0.01 M.The full-cell assembled using the composite electrode and graphite counter electrode works at 2.2 V in 3 M NaCl solution that equals to the highest values achieved yet for aqueous supercapacitors. This cell has a capacitance as high as 698.8 F g À1 at 5 mV s À1 and preserves its initial value even after 10 000 continuous CV cycles at 1000 mV s À1 . It also exhibits a high-energy density of 446.1 W h kg À1 at a power density of 366.7 W kg À1 , and it is still 65.2 W h kg À1 at 18.3 kW kg À1 . The asymmetric capacitor with 1 Â 1 cm 2 area successfully lit a red light-emitting diode.

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